Volcanic ash deposition and long-term vegetation change on Subantarctic Marion Island

NARCIS (Netherlands)

Yeloff, D.; Mauquoy, D.S.; Barber, K.; Way, S.; van Geel, B.; Turney, C.S.M.

2007-01-01

A c. 5500 year record of peatland development and vegetation change was generated from a core recovered from an Agrostis magellanica peat bog on subantarctic Marion Island, using palynomorph, plant macrofossil, and tephra analyses. Two tephra horizons (both 17 cm thick) were identified and dated to

Effect of long-term organic fertilization on the soil pore characteristics of greenhouse vegetable fields converted from rice-wheat rotation fields.

Science.gov (United States)

Xu, L Y; Wang, M Y; Shi, X Z; Yu, Q B; Shi, Y J; Xu, S X; Sun, W X

2018-08-01

The shift from rice-wheat rotation (RWR) to greenhouse vegetable soils has been widely practiced in China. Several studies have discussed the changes in soil properties with land-use changes, but few studies have sought to address the differences in soil pore properties, especially for fields based on long-term organic fertilization under greenhouse vegetable system from RWR fields. This study uses the X-ray computed tomography (CT) scanning and statistical analysis to compare the long-term effects of the conversion of organic greenhouse vegetable fields (over one year, nine years, and fourteen years) from RWR fields on the soil macropore structure as well as the influencing factors from samples obtained in Nanjing, Jiangsu, China, using the surface soil layer and triplicate samples. The results demonstrated that the macropore structure became more complex and stable, with a higher connectivity, fractal dimension (FD) and a lower degree of anisotropy (DA), as the greenhouse vegetable planting time increased. The total topsoil macroporosity increased considerably, but the rate of increase gradually decelerated with time. The transmission pores (round pores ranging from 50 to 500μm) increased with time, but the biopores (>2000μm) clearly decreased after nine years of use as greenhouse vegetable fields. Soil organic matter (OM) has a significant relationship with the soil pore structure characteristics, especially for the transmission pores. In addition, organic fertilization on the topsoil had a short-term effect on the pores, but the effect stabilized and had a weak influence on the pores over longer periods. These results suggested that organic fertilization was conducive for controlling soil degradation regarding it physical quality for water and oxygen availability in the short term. Copyright © 2018 Elsevier B.V. All rights reserved.

[Effects of a long-term intervention in a work cafeteria on employee vegetable intake].

Science.gov (United States)

Misawa, Akemi; Yoshita, Katsushi; Fukumura, Tomoe; Tanaka, Taichiro; Tamaki, Junko; Takebayashi, Toru; Kusaka, Yukinori; Nakagawa, Hideaki; Yamato, Hiroshi; Okayama, Akira; Miura, Katsuyuki; Okamura, Tomonori; Ueshima, Hirotsugu

2015-01-01

We examined the effects on employee vegetable intake of a long-term intervention in an employee work cafeteria. The subjects were approximately 1,200 employees (aged 19-61 years) of an industrial company in Fukui prefecture. We promoted the intake of typical Japanese style meals that combined three elements (staple foods, main dishes and vegetable dishes) to increase vegetables intake. We displayed all items on the menus of the employee cafeteria using three colors (yellow, red and green to denote three elements) to indicate healthy food choices for the maintenance of a healthy food environment. We advised employees to choose meals containing the three elements at the time of payment, for nutritional education (appropriate portion choice: APC). We evaluated the ratio of APC at the same time. To calculate the mean daily intake per person, we carried out a questionnaire survey similar to the "semi-quantitative food frequency questionnaire" and asked about the frequency and approximate intake of vegetables. The APC was 63.5% after one year of intervention, significantly increased to 82.1% after two years (p breakfast (p < 0.001), lunch (p < 0.001) and dinner (p = 0.011), and from vegetable juice (p = 0.030) significantly increased after three years of intervention. The consumption of pickles significantly decreased after three years of intervention (p = 0.009). It was estimated that the vegetable intake of men increased from 167.3 to 184.6 g, and that of women from 157.9 to 187.7 g. Employee estimated vegetable intake was significantly increased and that of pickles was significantly decreased by a long-term intervention (three years) in the employee work cafeteria.

The analysis of long-term changes in plant communities using large databases: the effect of stratified resampling.

NARCIS (Netherlands)

Haveman, R.; Janssen, J.A.M.

2008-01-01

Question: Releves in large phytosociological databases used for analysing long-term changes in plant communities are biased towards easily accessible places and species-rich stands. How does this bias influence trend analysis of floristic composition within a priori determined vegetation types and

Long-term ecophysiological responses to climate change

DEFF Research Database (Denmark)

Boesgaard, Kristine Stove; Ro-Poulsen, Helge

Plant physiology is affected by climate change. Acclimations of photosynthetic processes are induced by short-term changes in climatic conditions. Further acclimation can be caused by longterm adjustments to climate change due to ecosystem-feedbacks. The aim of this PhD was to investigate plant...... term responses of plant physiology to the climate change factors were investigated. In the CLIMAITE-experiment it has been shown that 2 years of treatment altered physiological responses in Deschampsiaand Calluna. In the work of this PhD similar responses were observed after 6 years of treatment...... physiological responses to climate change in a seasonal and long-term perspective. The effects of elevated CO2, passive night time warming and periodic summer drought as single factor and in combination, on plant physiology were investigated in the long-term multifactorial field experiment CLIMAITE in a Danish...

CLIMATE CHANGE: LONG-TERM TRENDS AND SHORT-TERM OSCILLATIONS

Institute of Scientific and Technical Information of China (English)

GAO Xin-quan; ZHANG Xin; QIAN Wei-hong

2006-01-01

Identifying the Northern Hemisphere (NH) temperature reconstruction and instrumental data for the past 1000 years shows that climate change in the last millennium includes long-term trends and various oscillations. Two long-term trends and the quasi-70-year oscillation were detected in the global temperature series for the last 140 years and the NH millennium series. One important feature was emphasized that temperature decreases slowly but it increases rapidly based on the analysis of different series. Benefits can be obtained of climate change from understanding various long-term trends and oscillations. Millennial temperature proxies from the natural climate system and time series of nonlinear model system are used in understanding the natural climate change and recognizing potential benefits by using the method of wavelet transform analysis. The results from numerical modeling show that major oscillations contained in numerical solutions on the interdecadal timescale are consistent with that of natural proxies. It seems that these oscillations in the climate change are not directly linked with the solar radiation as an external forcing. This investigation may conclude that the climate variability at the interdecadal timescale strongly depends on the internal nonlinear effects in the climate system.

Changing incentives for long-term gas contracts

International Nuclear Information System (INIS)

Bohi, D.R.

1992-01-01

There is much concern about the absence of long-term gas contracts with fixed price and quantity conditions, which until recent years was the standard way of doing business in the gas industry. These types of contracts performed a valuable service in the development of the gas industry, and there comparative absence today is sometimes thought to be one reason for the current malaise in the industry. One hears the argument that there must be some kind of 'market failure' that prevents buyers and sellers from entering into these long term arrangements, and recent changes in state and federal regulations are often cited as the cause of the problem. The purpose of the author's remarks is to argue that what is taken as a breakdown in the market may be simply a reaction to a decline in economic incentives to enter into long-term contracts with rigid price and quantity terms. This is, in other words, simply one more aspect of change in the gas business that Frank Heintz referred to in his opening remarks this morning. The author starts by giving a brief description of the motives for engaging in long-term contracts, and then describes how incentives to use long-term contracts have declined for both gas buyers and gas sellers. He concludes that the decline in the use of long-term contracts is not cause for regulatory concern, but a result of the continuing transformation of the gas business to one that more closely resembles other commodity markets

Influence of Vegetation on Long-term Phosphorus Sequestration in Subtropical Treatment Wetlands.

Science.gov (United States)

Bhomia, R K; Reddy, K R

2018-03-01

Sustainable operation of a treatment wetland depends on its continued treatment of influent water to achieve desired outflow water quality targets. Water treatment or nutrient reduction is attained by a combination of biotic and abiotic processes. We studied one of the world's largest treatment wetlands established to revive the Florida Everglades from impacts of excessive phosphorus (P) inputs. Phosphorus retained in the treatment wetlands is sequestered within the accumulated material via biotic and abiotic pathways that are influenced by the existing wetland vegetation. Recently accreted soils (RAS) provide a major sink for stored P, and long-term P removal efficiency of treatment wetlands is governed by the stability of accreted P because more stable P pools are less susceptible to mobilization and loss. We quantified reactive P (extracted with acid and alkali) and nonreactive P (not extracted with acid and alkali) pools in wetland soils by using an operationally defined P fractionation scheme and assessed the effect of emergent vs. submerged vegetation communities on stability of sequestered P. Reactive P comprised 63 to 79% of total P in wetland soils without a clear difference between two vegetation groups. The quantities of reactive P forms (inorganic vs. organic P) were significantly different between two vegetation types. A higher proportion of reactive P was stored as organic P in flocculent detrital organic matter (floc) and RAS under emergent vegetation (46-47% total P) in comparison with submerged vegetation (21-34% total P). The dominant P removal pathway in the submerged vegetation system was associated with calcium whereas plant uptake and peat burial appeared to be the main pathway in the emergent vegetation system. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Long-term effects of climate and land cover change on freshwater provision in the tropical Andes

Science.gov (United States)

Molina, A.; Vanacker, V.; Brisson, E.; Mora, D.; Balthazar, V.

2015-06-01

Andean headwater catchments play a pivotal role to supply fresh water for downstream water users. However, few long-term studies exist on the relative importance of climate change and direct anthropogenic perturbations on flow regimes. In this paper, we assess multi-decadal change in freshwater provision based on long time series (1974-2008) of hydrometeorological data and land cover reconstructions for a 282 km2 catchment located in the tropical Andes. Three main land cover change trajectories can be distinguished: (1) rapid decline of native vegetation in montane forest and páramo ecosystems in ~1/5 or 20% of the catchment area, (2) expansion of agricultural land by 14% of the catchment area, (3) afforestation of 12% of native páramo grasslands with exotic tree species in recent years. Given the strong temporal variability of precipitation and streamflow data related to El Niño-Southern Oscillation, we use empirical mode decomposition techniques to detrend the time series. The long-term increasing trend in rainfall is remarkably different from the observed changes in streamflow that exhibit a decreasing trend. Hence, observed changes in streamflow are not the result of long-term climate change but very likely result from direct anthropogenic disturbances after land cover change. Partial water budgets for montane cloud forest and páramo ecosystems suggest that the strongest changes in evaporative water losses are observed in páramo ecosystems, where progressive colonization and afforestation of high alpine grasslands leads to a strong increase in transpiration losses.

NDVI indicated long-term interannual changes in vegetation activities and their responses to climatic and anthropogenic factors in the Three Gorges Reservoir Region, China.

Science.gov (United States)

Wen, Zhaofei; Wu, Shengjun; Chen, Jilong; Lü, Mingquan

2017-01-01

Natural and social environmental changes in the China's Three Gorges Reservoir Region (TGRR) have received worldwide attention. Identifying interannual changes in vegetation activities in the TGRR is an important task for assessing the impact these changes have on the local ecosystem. We used long-term (1982-2011) satellite-derived Normalized Difference Vegetation Index (NDVI) datasets and climatic and anthropogenic factors to analyze the spatiotemporal patterns of vegetation activities in the TGRR, as well as their links to changes in temperature (TEM), precipitation (PRE), downward radiation (RAD), and anthropogenic activities. At the whole TGRR regional scale, a statistically significant overall uptrend in NDVI variations was observed in 1982-2011. More specifically, there were two distinct periods with different trends split by a breakpoint in 1991: NDVI first sharply increased prior to 1991, and then showed a relatively weak rate of increase after 1991. At the pixel scale, most parts of the TGRR experienced increasing NDVI before the 1990s but different trend change types after the 1990s: trends were positive in forests in the northeastern parts, but negative in farmland in southwest parts of the TGRR. The TEM warming trend was the main climate-related driver of uptrending NDVI variations pre-1990s, and decreasing PRE was the main climate factor (42%) influencing the mid-western farmland areas' NDVI variations post-1990s. We also found that anthropogenic factors such as population density, man-made ecological restoration, and urbanization have notable impacts on the TGRR's NDVI variations. For example, large overall trend slopes in NDVI were more likely to appear in TGRR regions with large fractions of ecological restoration within the last two decades. The findings of this study may help to build a better understanding of the mechanics of NDVI variations in the periods before and during TGDP construction for ongoing ecosystem monitoring and assessment in the

Impacts of vegetation change on groundwater recharge

Science.gov (United States)

Bond, W. J.; Verburg, K.; Smith, C. J.

2003-12-01

Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

Unravelling long-term vegetation change patterns in a binational watershed using multitemporal land cover data and historical photography

Science.gov (United States)

Villarreal, Miguel L.; Norman, Laura M.; Webb, Robert H.; Boyer, Diane E.; Turner, Raymond M.

2011-01-01

A significant amount of research conducted in the Sonoran Desert of North America has documented, both anecdotally and empirically, major vegetation changes over the past century due to human land use activities. However, many studies lack coincidental landscape-scale data characterizing the spatial and temporal manifestation of these changes. Vegetation changes in a binational (USA and Mexico) watershed were documented using a series of four land cover maps (1979-2009) derived from multispectral satellite imagery. Cover changes are compared to georeferenced, repeat oblique photographs dating from the late 19th century to present. Results indicate the expansion of grassland over the past 20 years following nearly a century of decline. Historical repeat photography documents early-mid 20th century mesquite invasions, but recent land cover data and rephotography demonstrate declines in xeroriparian/riparian mesquite communities in recent decades. These vegetation changes are variable over the landscape and influenced by topography and land management.

Functional Trait Changes, Productivity Shifts and Vegetation Stability in Mountain Grasslands during a Short-Term Warming.

Science.gov (United States)

Debouk, Haifa; de Bello, Francesco; Sebastià, Maria-Teresa

2015-01-01

Plant functional traits underlie vegetation responses to environmental changes such as global warming, and consequently influence ecosystem processes. While most of the existing studies focus on the effect of warming only on species diversity and productivity, we further investigated (i) how the structure of community plant functional traits in temperate grasslands respond to experimental warming, and (ii) whether species and functional diversity contribute to a greater stability of grasslands, in terms of vegetation composition and productivity. Intact vegetation turves were extracted from temperate subalpine grassland (highland) in the Eastern Pyrenees and transplanted into a warm continental, experimental site in Lleida, in Western Catalonia (lowland). The impacts of simulated warming on plant production and diversity, functional trait structure, and vegetation compositional stability were assessed. We observed an increase in biomass and a reduction in species and functional diversity under short-term warming. The functional structure of the grassland communities changed significantly, in terms of functional diversity and community-weighted means (CWM) for several traits. Acquisitive and fast-growing species with higher SLA, early flowering, erect growth habit, and rhizomatous strategy became dominant in the lowland. Productivity was significantly positively related to species, and to a lower extent, functional diversity, but productivity and stability after warming were more dependent on trait composition (CWM) than on diversity. The turves with more acquisitive species before warming changed less in composition after warming. Results suggest that (i) the short-term warming can lead to the dominance of acquisitive fast growing species over conservative species, thus reducing species richness, and (ii) the functional traits structure in grassland communities had a greater influence on the productivity and stability of the community under short-term warming

Functional Trait Changes, Productivity Shifts and Vegetation Stability in Mountain Grasslands during a Short-Term Warming.

Directory of Open Access Journals (Sweden)

Haifa Debouk

Full Text Available Plant functional traits underlie vegetation responses to environmental changes such as global warming, and consequently influence ecosystem processes. While most of the existing studies focus on the effect of warming only on species diversity and productivity, we further investigated (i how the structure of community plant functional traits in temperate grasslands respond to experimental warming, and (ii whether species and functional diversity contribute to a greater stability of grasslands, in terms of vegetation composition and productivity. Intact vegetation turves were extracted from temperate subalpine grassland (highland in the Eastern Pyrenees and transplanted into a warm continental, experimental site in Lleida, in Western Catalonia (lowland. The impacts of simulated warming on plant production and diversity, functional trait structure, and vegetation compositional stability were assessed. We observed an increase in biomass and a reduction in species and functional diversity under short-term warming. The functional structure of the grassland communities changed significantly, in terms of functional diversity and community-weighted means (CWM for several traits. Acquisitive and fast-growing species with higher SLA, early flowering, erect growth habit, and rhizomatous strategy became dominant in the lowland. Productivity was significantly positively related to species, and to a lower extent, functional diversity, but productivity and stability after warming were more dependent on trait composition (CWM than on diversity. The turves with more acquisitive species before warming changed less in composition after warming. Results suggest that (i the short-term warming can lead to the dominance of acquisitive fast growing species over conservative species, thus reducing species richness, and (ii the functional traits structure in grassland communities had a greater influence on the productivity and stability of the community under short-term

Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

Directory of Open Access Journals (Sweden)

Laura Ulsig

2017-01-01

Full Text Available Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI. This study investigates the potential of a Photochemical Reflectance Index (PRI, which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36–0.8, which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 > 0.6 in all cases. The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.

Long-term changes in river system hydrology in Texas

Directory of Open Access Journals (Sweden)

Y. Zhang

2018-06-01

Full Text Available Climate change and human actives are recognized as a topical issue that change long-term water budget, flow-frequency, and storage-frequency characteristics of different river systems. Texas is characterized by extreme hydrologic variability both spatially and temporally. Meanwhile, population and economic growth and accompanying water resources development projects have greatly impacted river flows throughout Texas. The relative effects of climate change, water resources development, water use, and other factors on long-term changes in river flow, reservoir storage, evaporation, water use, and other components of the water budgets of different river basins of Texas have been simulated in this research using the monthly version of the Water Rights Analysis Package (WRAP modelling system with input databases sets from the Texas Commission on Environmental Quality (TCEQ and Texas Water Development Board (TWDB. The results show that long-term changes are minimal from analysis monthly precipitation depths. Evaporation rates vary greatly seasonally and for much of the state appear to have a gradually upward trend. River/reservoir system water budgets and river flow characteristics have changed significantly during the past 75 years in response to water resources development and use.

Short-term changes in arterial inflammation predict long-term changes in atherosclerosis progression

Energy Technology Data Exchange (ETDEWEB)

Joseph, Philip [Massachusetts General Hospital and Harvard Medical School, Cardiology Division and Cardiac MR PET CT Program, Boston, MA (United States); McMaster University, Population Health Research Institute, Department of Medicine, and Department of Radiology, Hamilton, ON (Canada); Ishai, Amorina; Tawakol, Ahmed [Massachusetts General Hospital and Harvard Medical School, Cardiology Division and Cardiac MR PET CT Program, Boston, MA (United States); Mani, Venkatesh [Icahn School of Medicine at Mount Sinai School of Medicine, Translational and Molecular Imaging Institute and Department of Radiology, New York, NY (United States); Kallend, David [The Medicines Company, Parsippany, NJ (United States); Rudd, James H.F. [University of Cambridge, Division of Cardiovascular Medicine, Cambridge (United Kingdom); Fayad, Zahi A. [Icahn School of Medicine at Mount Sinai School of Medicine, Translational and Molecular Imaging Institute and Department of Radiology, New York, NY (United States); Icahn School of Medicine at Mount Sinai School of Medicine, Hess CSM Building Floor TMII, Rm S1-104, Translational and Molecular Imaging Institute and Department of Radiology, New York, NY (United States)

2017-01-15

It remains unclear whether changes in arterial wall inflammation are associated with subsequent changes in the rate of structural progression of atherosclerosis. In this sub-study of the dal-PLAQUE clinical trial, multi-modal imaging was performed using 18-fludeoxyglucose (FDG) positron emission tomography (PET, at 0 and 6 months) and magnetic resonance imaging (MRI, at 0 and 24 months). The primary objective was to determine whether increasing FDG uptake at 6 months predicted atherosclerosis progression on MRI at 2 years. Arterial inflammation was measured by the carotid FDG target-to-background ratio (TBR), and atherosclerotic plaque progression was defined as the percentage change in carotid mean wall area (MWA) and mean wall thickness (MWT) on MRI between baseline and 24 months. A total of 42 participants were included in this sub-study. The mean age of the population was 62.5 years, and 12 (28.6 %) were women. In participants with (vs. without) any increase in arterial inflammation over 6 months, the long-term changes in both MWT (% change MWT: 17.49 % vs. 1.74 %, p = 0.038) and MWA (% change MWA: 25.50 % vs. 3.59 %, p = 0.027) were significantly greater. Results remained significant after adjusting for clinical and biochemical covariates. Individuals with no increase in arterial inflammation over 6 months had no significant structural progression of atherosclerosis over 24 months as measured by MWT (p = 0.616) or MWA (p = 0.373). Short-term changes in arterial inflammation are associated with long-term structural atherosclerosis progression. These data support the concept that therapies that reduce arterial inflammation may attenuate or halt progression of atherosclerosis. (orig.)

Short-term changes in arterial inflammation predict long-term changes in atherosclerosis progression

International Nuclear Information System (INIS)

Joseph, Philip; Ishai, Amorina; Tawakol, Ahmed; Mani, Venkatesh; Kallend, David; Rudd, James H.F.; Fayad, Zahi A.

2017-01-01

It remains unclear whether changes in arterial wall inflammation are associated with subsequent changes in the rate of structural progression of atherosclerosis. In this sub-study of the dal-PLAQUE clinical trial, multi-modal imaging was performed using 18-fludeoxyglucose (FDG) positron emission tomography (PET, at 0 and 6 months) and magnetic resonance imaging (MRI, at 0 and 24 months). The primary objective was to determine whether increasing FDG uptake at 6 months predicted atherosclerosis progression on MRI at 2 years. Arterial inflammation was measured by the carotid FDG target-to-background ratio (TBR), and atherosclerotic plaque progression was defined as the percentage change in carotid mean wall area (MWA) and mean wall thickness (MWT) on MRI between baseline and 24 months. A total of 42 participants were included in this sub-study. The mean age of the population was 62.5 years, and 12 (28.6 %) were women. In participants with (vs. without) any increase in arterial inflammation over 6 months, the long-term changes in both MWT (% change MWT: 17.49 % vs. 1.74 %, p = 0.038) and MWA (% change MWA: 25.50 % vs. 3.59 %, p = 0.027) were significantly greater. Results remained significant after adjusting for clinical and biochemical covariates. Individuals with no increase in arterial inflammation over 6 months had no significant structural progression of atherosclerosis over 24 months as measured by MWT (p = 0.616) or MWA (p = 0.373). Short-term changes in arterial inflammation are associated with long-term structural atherosclerosis progression. These data support the concept that therapies that reduce arterial inflammation may attenuate or halt progression of atherosclerosis. (orig.)

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

DEFF Research Database (Denmark)

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

2011-01-01

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

Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution

Directory of Open Access Journals (Sweden)

P. A. Troch

2013-06-01

Full Text Available Budyko (1974 postulated that long-term catchment water balance is controlled to first order by the available water and energy. This leads to the interesting question of how do landscape characteristics (soils, geology, vegetation and climate properties (precipitation, potential evaporation, number of wet and dry days interact at the catchment scale to produce such a simple and predictable outcome of hydrological partitioning? Here we use a physically-based hydrologic model separately parameterized in 12 US catchments across a climate gradient to decouple the impact of climate and landscape properties to gain insight into the role of climate-vegetation-soil interactions in long-term hydrologic partitioning. The 12 catchment models (with different paramterizations are subjected to the 12 different climate forcings, resulting in 144 10 yr model simulations. The results are analyzed per catchment (one catchment model subjected to 12 climates and per climate (one climate filtered by 12 different model parameterization, and compared to water balance predictions based on Budyko's hypothesis (E/P = ϕ (Ep/P; E: evaporation, P: precipitation, Ep: potential evaporation. We find significant anti-correlation between average deviations of the evaporation index (E/P computed per catchment vs. per climate, compared to that predicted by Budyko. Catchments that on average produce more E/P have developed in climates that on average produce less E/P, when compared to Budyko's prediction. Water and energy seasonality could not explain these observations, confirming previous results reported by Potter et al. (2005. Next, we analyze which model (i.e., landscape filter characteristics explain the catchment's tendency to produce more or less E/P. We find that the time scale that controls subsurface storage release explains the observed trend. This time scale combines several geomorphologic and hydraulic soil properties. Catchments with relatively longer

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.

Improving simulated long-term responses of vegetation to temperature and precipitation extremes using the ACME land model

Science.gov (United States)

Ricciuto, D. M.; Warren, J.; Guha, A.

2017-12-01

While carbon and energy fluxes in current Earth system models generally have reasonable instantaneous responses to extreme temperature and precipitation events, they often do not adequately represent the long-term impacts of these events. For example, simulated net primary productivity (NPP) may decrease during an extreme heat wave or drought, but may recover rapidly to pre-event levels following the conclusion of the extreme event. However, field measurements indicate that long-lasting damage to leaves and other plant components often occur, potentially affecting the carbon and energy balance for months after the extreme event. The duration and frequency of such extreme conditions is likely to shift in the future, and therefore it is critical for Earth system models to better represent these processes for more accurate predictions of future vegetation productivity and land-atmosphere feedbacks. Here we modify the structure of the Accelerated Climate Model for Energy (ACME) land surface model to represent long-term impacts and test the improved model against observations from experiments that applied extreme conditions in growth chambers. Additionally, we test the model against eddy covariance measurements that followed extreme conditions at selected locations in North America, and against satellite-measured vegetation indices following regional extreme events.

Initial Analyses of Change Detection Capabilities and Data Redundancies in the Long Term Resource Monitoring Program

National Research Council Canada - National Science Library

Lubinski, Kenneth

2001-01-01

Evaluations of Long Term Resource Monitoring Program sampling designs for water quality, fish, aquatic vegetation, and macroinvertebrates were initiated in 1999 by analyzing data collected since 1992...

Microbial and plant ecology of a long-term TNT-contaminated site

International Nuclear Information System (INIS)

Travis, Emma R.; Bruce, Neil C.; Rosser, Susan J.

2008-01-01

The contamination of the environment with explosive residues presents a serious ecological problem at sites across the world, with the highly toxic compound trinitrotoluene (TNT) the most widespread contaminant. This study examines the soil microbial community composition across a long-term TNT-contaminated site. It also investigates the extent of nitroaromatic contamination and its effect on vegetation. Concentrations of TNT and its metabolites varied across the site and this was observed to dramatically impact on the extent and diversity of the vegetation, with the most heavily contaminated area completely devoid of vegetation. Bryophytes were seen to be particularly sensitive to TNT contamination. The microbial population experienced both a reduction in culturable bacterial numbers and a shift in composition at the high concentrations of TNT. DGGE and community-level physiological profiling (CLPP) revealed a clear change in both the genetic and functional diversity of the soil when soil was contaminated with TNT. - Long-term contamination of soil with TNT reduces the extent and diversity of vegetation, decreases culturable bacterial numbers and shifts the microbial community composition

Long-term Diet and Biomarker Changes after a Short-term Intervention among Hispanic Breast Cancer Survivors: The ¡Cocinar Para Su Salud! Randomized Controlled Trial.

Science.gov (United States)

Greenlee, Heather; Ogden Gaffney, Ann; Aycinena, A Corina; Koch, Pam; Contento, Isobel; Karmally, Wahida; Richardson, John M; Shi, Zaixing; Lim, Emerson; Tsai, Wei-Yann; Santella, Regina M; Blaner, William S; Clugston, Robin D; Cremers, Serge; Pollak, Susan; Sirosh, Iryna; Crew, Katherine D; Maurer, Matthew; Kalinsky, Kevin; Hershman, Dawn L

2016-11-01

Among Hispanic breast cancer survivors, we examined the long-term effects of a short-term culturally based dietary intervention on increasing fruits/vegetables (F/V), decreasing fat, and changing biomarkers associated with breast cancer recurrence risk. Spanish-speaking women (n = 70) with a history of stage 0-III breast cancer who completed treatment were randomized to ¡Cocinar Para Su Salud! (n = 34), a culturally based 9-session program (24 hours over 12 weeks, including nutrition education, cooking classes, and food-shopping field trips), or a control group (n = 36, written dietary recommendations for breast cancer survivors). Diet recalls, fasting blood, and anthropometric measures were collected at baseline, 6, and 12 months. We report changes between groups at 12 months in dietary intake and biomarkers using 2-sample Wilcoxon t tests and generalized estimating equation (GEE) models. At 12 months, the intervention group compared with the control group reported higher increases in mean daily F/V servings (total: +2.0 vs. -0.4; P Salud! program was effective at increasing long-term F/V intake in Hispanic breast cancer survivors and changed biomarkers associated with breast cancer recurrence risk. It is possible for short-term behavioral interventions to have long-term effects on behaviors and biomarkers in minority cancer patient populations. Results can inform future study designs. Cancer Epidemiol Biomarkers Prev; 25(11); 1491-502. ©2016 AACR. ©2016 American Association for Cancer Research.

Long-term trends in vegetation phenology and productivity over Namaqualand using the GIMMS AVHRR NDVI3g data from 1982 to 2011

CSIR Research Space (South Africa)

Davis, CL

2017-07-01

Full Text Available Vegetation monitoring of arid and semi-arid environments using remotely sensed vegetation indices over long periods of time is essential to improve the understanding of the processes related to change. In this paper, 30 years of biweekly AVHRR NDVI3...

Long-term effects of submergence and wetland vegetation on metals in a 90-year old abandoned Pb-Zn mine tailings pond

International Nuclear Information System (INIS)

Jacob, Donna L.; Otte, Marinus L.

2004-01-01

A Pb-Zn tailings pond, abandoned for approximately 90 years, has been naturally colonized by Glyceria fluitans and is an excellent example of long-term metal retention in tailings ponds under various water cover and vegetation conditions. Shallow/intermittently flooded areas (dry zone) were unvegetated and low in organic matter (OM) content. Permanently flooded areas were either unvegetated with low OM, contained dead vegetation and high OM, or living plants and high OM. It was expected that either water cover or high OM would result in enhanced reducing conditions and lower metal mobility, but live plants would increase metal mobility due to root radial oxygen loss. The flooded low OM tailings showed higher As and Fe mobility compared with dry low OM tailings. In the permanently flooded areas without live vegetation, the high OM content decreased Zn mobility and caused extremely high concentrations of acid-volatile sulfides (AVS). In areas with high OM, living plants significantly increased Zn mobility and decreased concentrations of AVS, indicating root induced sediment oxidation or decreased sulfate-reduction. This is the first study reporting the ability of wetland plants to affect the metal mobility and AVS in long-term (decades), unmanaged tailings ponds. - Metal and acid-volatile sulfide concentrations were affected differently by flooding vegetation

Long-term runoff changes in regions of Slovakia

International Nuclear Information System (INIS)

Miklanek, Pavol; Pekarova; Pavla

2004-01-01

Mean annual runoff variability includes both natural and anthropogenic (climate change) impacts. Aim of the paper is to identify the long-term trends and the cyclic runoff components of selected Slovak rivers for the period 1931-2000, and of the Danube river for the period 1840-2000. The variability is analysed by the long-term runoff trends of 27 Slovak rivers for the period 1931-2000. The stations were included into the Slovak National Climate Program and they are supposed not to be influenced by anthropogenic activities except of possible climate change. Comparison of the monthly runoff series of the 27 rivers allowed us to draw 3 regions with different runoff trends on the territory of Slovakia (constant trend in Northern and Eastern Slovakia, slow decrease in Central Slovakia, and rapid decrease in Southern Slovakia; The identification of different cyclic components of the runoff series is included. The length of the series allows to identify the 22-year cycles as maximum. By means of the longer runoff series of the Danube river it is shown that the more dry periods occurred in the central Europe and Slovakia in mid 19 th century. The longer Danube series were used also to find the longer runoff cycles of about 31 and 46 years. The mean annual temperature in Europe was lower by 0.6 o C in mid 19 th century compared to 1990s. The temperature increase is put down to climate change impact. The driest period shown by Danube runoff series in mid 19 th century occurred before the start of the climate change. Therefore it is probable that the long-term runoff variability has its own dynamics as well. (Author)

Effects of a long-term disturbance on arthropods and vegetation in subalpine wetlands: manifestations of pack stock grazing in early versus mid-season.

Directory of Open Access Journals (Sweden)

Jeffrey G Holmquist

Full Text Available Conclusions regarding disturbance effects in high elevation or high latitude ecosystems based solely on infrequent, long-term sampling may be misleading, because the long winters may erase severe, short-term impacts at the height of the abbreviated growing season. We separated a long-term effects of pack stock grazing, manifested in early season prior to stock arrival, from b additional pack stock grazing effects that might become apparent during annual stock grazing, by use of paired grazed and control wet meadows that we sampled at the beginning and end of subalpine growing seasons. Control meadows had been closed to grazing for at least two decades, and meadow pairs were distributed across Sequoia National Park, California, USA. The study was thus effectively a landscape-scale, long-term manipulation of wetland grazing. We sampled arthropods at these remote sites and collected data on associated vegetation structure. Litter cover and depth, percent bare ground, and soil strength had negative responses to grazing. In contrast, fauna showed little response to grazing, and there were overall negative effects for only three arthropod families. Mid-season and long-term results were generally congruent, and the only indications of lower faunal diversity on mid-season grazed wetlands were trends of lower abundance across morphospecies and lower diversity for canopy fauna across assemblage metrics. Treatment x Season interactions almost absent. Thus impacts on vegetation structure only minimally cascaded into the arthropod assemblage and were not greatly intensified during the annual growing season. Differences between years, which were likely a response to divergent snowfall patterns, were more important than differences between early and mid-season. Reliance on either vegetation or faunal metrics exclusively would have yielded different conclusions; using both flora and fauna served to provide a more integrative view of ecosystem response.

Effects of a long-term disturbance on arthropods and vegetation in subalpine wetlands: manifestations of pack stock grazing in early versus mid-season.

Science.gov (United States)

Holmquist, Jeffrey G; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A

2013-01-01

Conclusions regarding disturbance effects in high elevation or high latitude ecosystems based solely on infrequent, long-term sampling may be misleading, because the long winters may erase severe, short-term impacts at the height of the abbreviated growing season. We separated a) long-term effects of pack stock grazing, manifested in early season prior to stock arrival, from b) additional pack stock grazing effects that might become apparent during annual stock grazing, by use of paired grazed and control wet meadows that we sampled at the beginning and end of subalpine growing seasons. Control meadows had been closed to grazing for at least two decades, and meadow pairs were distributed across Sequoia National Park, California, USA. The study was thus effectively a landscape-scale, long-term manipulation of wetland grazing. We sampled arthropods at these remote sites and collected data on associated vegetation structure. Litter cover and depth, percent bare ground, and soil strength had negative responses to grazing. In contrast, fauna showed little response to grazing, and there were overall negative effects for only three arthropod families. Mid-season and long-term results were generally congruent, and the only indications of lower faunal diversity on mid-season grazed wetlands were trends of lower abundance across morphospecies and lower diversity for canopy fauna across assemblage metrics. Treatment x Season interactions almost absent. Thus impacts on vegetation structure only minimally cascaded into the arthropod assemblage and were not greatly intensified during the annual growing season. Differences between years, which were likely a response to divergent snowfall patterns, were more important than differences between early and mid-season. Reliance on either vegetation or faunal metrics exclusively would have yielded different conclusions; using both flora and fauna served to provide a more integrative view of ecosystem response.

New views on changing Arctic vegetation

Science.gov (United States)

Kennedy, Robert E.

2012-03-01

means of tracking retrospective changes in Arctic and boreal vegetation. These images are attractive because they are consistent over time, are good at mapping vegetation, are available for areas difficult to reach on the ground, and are of broad geographic extent. In a now-classic study, Myneni et al (1998) used historical reanalysis of AVHRR image data to document changes in vegetation phenology at continental scales in the northern hemisphere, finding patterns of change consistent with impacts of increased growing season in boreal and near-polar regions. The year 2000 launch of the MODIS sensors has allowed even more robust assessment of vegetation change in the Arctic (de Beurs and Henebry 2010) and at global scales (Zhao and Running 2010). Despite opening a window into vegetation change in the Arctic, these studies provide a relatively coarsely filtered view of change. To track trends occurring before the year 2000, researchers are constrained to the large pixel sizes of the AVHRR instrument (nominally 1 km, but typically 4-8 km for derived datasets). Even the finer grain of MODIS (250 m to 1 km resolution) obscures many important natural and anthropogenically derived spatial patterns. The effects of climate change may exacerbate contrasts in competitive status of different vegetative groups (Klady et al 2011, Pieper et al 2011, Seastedt et al 2004). Resolving mechanisms of response requires empirical observation at the scale of individual vegetative communities. Thus, the new work of Fraser et al (2011) represents a critical milestone in climate change related monitoring of Arctic vegetation. Their work is important in three ways. First, the authors provide the first spatially explicit, continuous record of long-term trends in Arctic vegetation condition at a pixel resolution of 30 m. Based on Landsat Thematic Mapper (TM) data reaching back to the mid 1980s, the work required the overcoming of several key methodological challenges to build a dataset from which

Long-term changes and trends in the upper atmosphere - An introduction

Czech Academy of Sciences Publication Activity Database

Laštovička, Jan; Akmaev, R. A.; Emmert, J. T.

2009-01-01

Roč. 71, 14-15 (2009), s. 1511-1513 ISSN 1364-6826 Institutional research plan: CEZ:AV0Z30420517 Keywords : long-term changes * long-term trends * upper atmosphere Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.643, year: 2009 http://www.sciencedirect.com/science/journal/13646826

Orbital scale vegetation change in Africa

Science.gov (United States)

Dupont, Lydie

2011-12-01

Palynological records of Middle and Late Pleistocene marine sediments off African shores is reviewed in order to reveal long-term patterns of vegetation change during climate cycles. Whether the transport of pollen and spores from the source areas on the continent to the ocean floor is mainly by wind or predominantly by rivers depends on the region. Despite the differences in transportation, accumulation rates in the marine sediments decline exponentially with distance to the shore. The marine sediments provide well-dated records presenting the vegetation history of the main biomes of western and southern Africa. The extent of different biomes varied with the climate changes of the glacial interglacial cycle. The Mediterranean forest area expanded during interglacials, the northern Saharan desert during glacials, and the semi-desert area in between during the transitions. In the sub-Saharan mountains ericaceous scrubland spread mainly during glacials and the mountainous forest area often increased during intermediate periods. Savannahs extended or shifted to lower latitudes during glacials. While the representation of the tropical rain forest fluctuated with summer insolation and precession, that of the subtropical biomes showed more obliquity variability or followed the pattern of glacial and interglacials.

Reconciling change blindness with long-term memory for objects.

Science.gov (United States)

Wood, Katherine; Simons, Daniel J

2017-02-01

How can we reconcile remarkably precise long-term memory for thousands of images with failures to detect changes to similar images? We explored whether people can use detailed, long-term memory to improve change detection performance. Subjects studied a set of images of objects and then performed recognition and change detection tasks with those images. Recognition memory performance exceeded change detection performance, even when a single familiar object in the postchange display consistently indicated the change location. In fact, participants were no better when a familiar object predicted the change location than when the displays consisted of unfamiliar objects. When given an explicit strategy to search for a familiar object as a way to improve performance on the change detection task, they performed no better than in a 6-alternative recognition memory task. Subjects only benefited from the presence of familiar objects in the change detection task when they had more time to view the prechange array before it switched. Once the cost to using the change detection information decreased, subjects made use of it in conjunction with memory to boost performance on the familiar-item change detection task. This suggests that even useful information will go unused if it is sufficiently difficult to extract.

Long-term memory and volatility clustering in high-frequency price changes

Science.gov (United States)

oh, Gabjin; Kim, Seunghwan; Eom, Cheoljun

2008-02-01

We studied the long-term memory in diverse stock market indices and foreign exchange rates using Detrended Fluctuation Analysis (DFA). For all high-frequency market data studied, no significant long-term memory property was detected in the return series, while a strong long-term memory property was found in the volatility time series. The possible causes of the long-term memory property were investigated using the return data filtered by the AR(1) model, reflecting the short-term memory property, the GARCH(1,1) model, reflecting the volatility clustering property, and the FIGARCH model, reflecting the long-term memory property of the volatility time series. The memory effect in the AR(1) filtered return and volatility time series remained unchanged, while the long-term memory property diminished significantly in the volatility series of the GARCH(1,1) filtered data. Notably, there is no long-term memory property, when we eliminate the long-term memory property of volatility by the FIGARCH model. For all data used, although the Hurst exponents of the volatility time series changed considerably over time, those of the time series with the volatility clustering effect removed diminish significantly. Our results imply that the long-term memory property of the volatility time series can be attributed to the volatility clustering observed in the financial time series.

Detecting robust signals of interannual variability of gross primary productivity in Asia from multiple terrestrial carbon cycle models and long-term satellite-based vegetation data

Science.gov (United States)

Ichii, K.; Kondo, M.; Ueyama, M.; Kato, T.; Ito, A.; Sasai, T.; Sato, H.; Kobayashi, H.; Saigusa, N.

2014-12-01

Long term record of satellite-based terrestrial vegetation are important to evaluate terrestrial carbon cycle models. In this study, we demonstrate how multiple satellite observation can be used for evaluating past changes in gross primary productivity (GPP) and detecting robust anomalies in terrestrial carbon cycle in Asia through our model-data synthesis analysis, Asia-MIP. We focused on the two different temporal coverages: long-term (30 years; 1982-2011) and decadal (10 years; 2001-2011; data intensive period) scales. We used a NOAA/AVHRR NDVI record for long-term analysis and multiple satellite data and products (e.g. Terra-MODIS, SPOT-VEGETATION) as historical satellite data, and multiple terrestrial carbon cycle models (e.g. BEAMS, Biome-BGC, ORCHIDEE, SEIB-DGVM, and VISIT). As a results of long-term (30 years) trend analysis, satellite-based time-series data showed that approximately 40% of the area has experienced a significant increase in the NDVI, while only a few areas have experienced a significant decreasing trend over the last 30 years. The increases in the NDVI were dominant in the sub-continental regions of Siberia, East Asia, and India. Simulations using the terrestrial biosphere models also showed significant increases in GPP, similar to the results for the NDVI, in boreal and temperate regions. A modeled sensitivity analysis showed that the increases in GPP are explained by increased temperature and precipitation in Siberia. Precipitation, solar radiation, CO2fertilization and land cover changes are important factors in the tropical regions. However, the relative contributions of each factor to GPP changes are different among the models. Year-to-year variations of terrestrial GPP were overall consistently captured by the satellite data and terrestrial carbon cycle models if the anomalies are large (e.g. 2003 summer GPP anomalies in East Asia and 2002 spring GPP anomalies in mid to high latitudes). The behind mechanisms can be consistently

A Remote Sensing and GIS Approach to Study the Long-Term Vegetation Recovery of a Fire-Affected Pine Forest in Southern Greece

Directory of Open Access Journals (Sweden)

Foula Nioti

2015-06-01

Full Text Available Management strategies and silvicultural treatments of fire-prone ecosystems often rely on knowledge of the regeneration potential and long-term recovery ability of vegetation types. Remote sensing and GIS applications are valuable tools providing cost-efficient information on vegetation recovery patterns and their associated environmental factors. In this study we used an ordinal classification scheme to describe the land cover changes induced by a wildfire that occurred in 1983 in Pinus brutia woodlands on Karpathos Aegean Island, south-eastern Greece. As a proxy variable that indicates ecosystem recovery, we also estimated the difference between the NDVI and NBR indices a few months (1984 and almost 30 years after the fire (2012. Environmental explanatory variables were selected using a digital elevation model and various thematic maps. To identify the most influential environmental factors contributing to woodland recovery, binary logistic regression and linear regression techniques were applied. The analyses showed that although a large proportion of the P. brutia woodland has recovered 26 years after the fire event, a considerable amount of woodland had turned into scrub vegetation. Altitude, slope inclination, solar radiation, and pre-fire woodland physiognomy were identified as dominant factors influencing the vegetation’s recovery probability. Additionally, altitude and inclination are the variables that explain changes in the satellite remote sensing vegetation indices reflecting the recovery potential. Pinus brutia showed a good post-fire recovery potential, especially in parts of the study area with increased moisture availability.

Long-term relationship between climate change and nomadic migration in historical China

Directory of Open Access Journals (Sweden)

Qing Pei

2014-06-01

Full Text Available We investigated the relationship between a 2000-year history of nomadic migration and climate change in historical China. By using updated data and statistical methods, the study solved several unanswered questions from past research about the relationship between climate change and the nomadic migration, especially over the long term and on a large spatial scale. The study used correlation analysis, multiple regression analysis, and Granger causality analysis to quantitatively verify the following causal pathway: climate change â†' nomadic migration â†' conflicts between pastoralists and agriculturalists. In the long term, precipitation was a statistically more influential factor on nomadic migration than temperature in historical China. How climate change affects the migration of nomadic minorities in the long term is theoretically explained based on the Push-Pull model as well as statistical evidence.

Vegetation Change in Interior Alaska Over the Last Four Decades

Science.gov (United States)

Huhman, H.; Dewitz, J.; Cristobal, J.; Prakash, A.

2017-12-01

The Arctic has become a generally warmer place over the past decades leading to earlier snowmelt, permafrost degradation and changing plant communities. One area in particular, vegetation change, is responding relatively rapidly to climate change, impacting the surrounding environment with changes to forest fire regime, forest type, forest resiliency, habitat availability for subsistence flora and fauna, hydrology, among others. To quantify changes in vegetation in the interior Alaska boreal forest over the last four decades, this study uses the National Land Cover Database (NLCD) decision-tree based classification methods, using both C5 and ERDAS Imagine software, to classify Landsat Surface Reflectance Images into the following NLCD-consistent vegetation classes: planted, herbaceous, shrubland, and forest (deciduous, evergreen and mixed). The results of this process are a total of four vegetation cover maps, that are freely accessible to the public, one for each decade in the 1980's, 1990's, 2000's, and a current map for 2017. These maps focus on Fairbanks, Alaska and the surrounding area covering approximately 36,140 square miles. The maps are validated with over 4,000 ground truth points collected through organizations such as the Landfire Project and the Long Term Ecological Research Network, as well as vegetation and soil spectra collected from the study area concurrent with the Landsat satellite over-passes with a Spectral Evolution PSR+ 3500 spectro-radiometer (0.35 - 2.5 μm). We anticipate these maps to be viewed by a wide user-community and may aid in preparing the residents of Alaska for changes in their subsistence food sources and will contribute to the scientific community in understanding the variety of changes that can occur in response to changing vegetation.

Terrestrial transect study on driving mechanism of vegetation changes

Institute of Scientific and Technical Information of China (English)

2008-01-01

In terms of Chinese climate-vegetation model based on the classification of plant functional types, to- gether with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2 and SRES-B2) in China from the highest and the lowest emission scenarios of greenhouse gases, the distribution patterns of vegetation types and their changes along the Northeast China Transect (NECT) and the North-South Transect of Eastern China (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate, and the major factors driving the vegetation changes were water and heat. However, the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensi- tive to heat factors than to water factors. Thus, in the future climate warming will significantly affect vegetation distribution patterns.

Medium-long term soil resilience against different disturbances: wildfires, silvicultural treatments and climate change

Science.gov (United States)

Hedo de Santiago, Javier; Borja, Manuel Esteban Lucas; de las Heras, Jorge

2016-04-01

Soils of semiarid Mediterranean forest ecosystems are very fragile and sensitive to changes due to different anthropogenic and natural disturbances. The increasing vulnerability of semiarid lands within this world framework has generated growing awareness in the field of research, with highly intensified study into soils properties. One of the main problems of Mediterranean forests is wildfire disturbance. Fire should be considered more an ecological factor but, in contrast to the role of fire, it is now a closely related factor to human action. On the other hand, to improve the recovery of forest communities after fire, silvicultural treatments are needed and, for that matter, another disturbance is added to the ecosystem. By last, climate change is also affecting the fire regime increasing fire frequency and burned area, enhancing the destructiveness to Mediterranean ecosystems. After all of these three disturbances, changes in vegetation dynamics and soil properties are expected to occur due to the plant-soil feedback. Soil plays an essential role in the forest ecosystem's fertility and stability and specifically soil microorganisms, which accomplish reactions to release soil nutrients for vegetation development, for that is essential to enlarge knowledge about soil properties resilience in semiarid forest ecosystems. Physico-chemical and microbiological soil properties, and enzyme activities have been studied in two Aleppo pine forest stands that have suffered three disturbances: 1) a wildfire event, 2) silvicultural treatments (thinning) and 3) an artificial drought (simulating climate change) and results showed that soil recovered after 15 years. Final results showed that soils have been recovered from the three disturbances at the medium-long term.

Permafrost warming and vegetation changes in continental Antarctica

International Nuclear Information System (INIS)

Guglielmin, Mauro; Dalle Fratte, Michele; Cannone, Nicoletta

2014-01-01

Continental Antarctica represents the last pristine environment on Earth and is one of the most suitable contexts to analyze the relations between climate, active layer and vegetation. In 2000 we started long-term monitoring of the climate, permafrost, active layer and vegetation in Victoria Land, continental Antarctica. Our data confirm the stability of mean annual and summer air temperature, of snow cover, and an increasing trend of summer incoming short wave radiation. The active layer thickness is increasing at a rate of 0.3 cm y −1 . The active layer is characterized by large annual and spatial differences. The latter are due to scarce vegetation, a patchy and very thin organic layer and large spatial differences in snow accumulation. The active layer thickening, probably due to the increase of incoming short wave radiation, produced a general decrease of the ground water content due to the better drainage of the ground. The resultant drying may be responsible for the decline of mosses in xeric sites, while it provided better conditions for mosses in hydric sites, following the species-specific water requirements. An increase of lichen vegetation was observed where the climate drying occurred. This evidence emphasizes that the Antarctic continent is experiencing changes that are in total contrast to the changes reported from maritime Antarctica. (paper)

The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought

KAUST Repository

Meng, X. H.

2014-04-01

Moderate Resolution Imaging Spectroradiometer (MODIS)-derived vegetation fraction data were used to update the boundary conditions of the advanced research Weather Research and Forecasting (WRF) Model to assess the influence of realistic vegetation cover on climate simulations in southeast Australia for the period 2000–08. Results show that modeled air temperature was improved when MODIS data were incorporated, while precipitation changes little with only a small decrease in the bias. Air temperature changes in different seasons reflect the variability of vegetation cover well, while precipitation changes have a more complicated relationship to changes in vegetation fraction. Both MODIS and climatology-based simulation experiments capture the overall precipitation changes, indicating that precipitation is dominated by the large-scale circulation, with local vegetation changes contributing variations around these. Simulated feedbacks between vegetation fraction, soil moisture, and drought over southeast Australia were also investigated. Results indicate that vegetation fraction changes lag precipitation reductions by 6–8 months in nonarid regions. With the onset of the 2002 drought, a potential fast physical mechanism was found to play a positive role in the soil moisture–precipitation feedback, while a slow biological mechanism provides a negative feedback in the soil moisture–precipitation interaction on a longer time scale. That is, in the short term, a reduction in soil moisture leads to a reduction in the convective potential and, hence, precipitation, further reducing the soil moisture. If low levels of soil moisture persist long enough, reductions in vegetation cover and vigor occur, reducing the evapotranspiration and thus reducing the soil moisture decreases and dampening the fast physical feedback. Importantly, it was observed that these feedbacks are both space and time dependent.

Long-Term Studies of Prescribed Burning in Loblolly Pine Forests of the Southeastern Coastal Plain

Science.gov (United States)

Thomas A. Waldrop; David H. van Lear; F. Thomas Lloyd; William R. Harms

1987-01-01

Prescribed fire provides many benefits in southern pine A study begun in 1946 provides a unique opportunity stands. to observe long-term changes in understory vegetation, soil properties, and overstory tree growth caused by repeated burning.

Long-term CO2 fertilization increases vegetation productivity and has little effect on hydrological partitioning in tropical rainforests

Science.gov (United States)

Yang, Yuting; Donohue, Randall J.; McVicar, Tim R.; Roderick, Michael L.; Beck, Hylke E.

2016-08-01

Understanding how tropical rainforests respond to elevated atmospheric CO2 concentration (eCO2) is essential for predicting Earth's carbon, water, and energy budgets under future climate change. Here we use long-term (1982-2010) precipitation (P) and runoff (Q) measurements to infer runoff coefficient (Q/P) and evapotranspiration (E) trends across 18 unimpaired tropical rainforest catchments. We complement that analysis by using satellite observations coupled with ecosystem process modeling (using both "top-down" and "bottom-up" perspectives) to examine trends in carbon uptake and relate that to the observed changes in Q/P and E. Our results show there have been only minor changes in the satellite-observed canopy leaf area over 1982-2010, suggesting that eCO2 has not increased vegetation leaf area in tropical rainforests and therefore any plant response to eCO2 occurs at the leaf level. Meanwhile, observed Q/P and E also remained relatively constant in the 18 catchments, implying an unchanged hydrological partitioning and thus approximately conserved transpiration under eCO2. For the same period, using a top-down model based on gas exchange theory, we predict increases in plant assimilation (A) and light use efficiency (ɛ) at the leaf level under eCO2, the magnitude of which is essentially that of eCO2 (i.e., 12% over 1982-2010). Simulations from 10 state-of-the-art bottom-up ecosystem models over the same catchments also show that the direct effect of eCO2 is to mostly increase A and ɛ with little impact on E. Our findings add to the current limited pool of knowledge regarding the long-term eCO2 impacts in tropical rainforests.

Changes in the skeleton after long-term treatment with retinoids

Energy Technology Data Exchange (ETDEWEB)

Montag, M.; Reiser, M.; Hamm, H.; Traupe, H.; Vogt, H.J.

1988-07-01

The synthetic retinoids, the vitamin-A-derivatives ethretinate and isotretinoin, have substantially enlarged the therapeutic arsenal in dermatology. They are primarily used in severe cases of acne and cornification disorders. In the majority of cases, long-term treatment is necessary. Certain side effects in the skeletal system can occur, e.g., osteoporosis, premature epiphyseal closure, and changes similar to DISH (diffuse idiopathic skeletal hyperostosis). We discuss the reports in the literature and our own observations in 31 patients treated at the Westphalian Wilhelms University in Muenster, as well as at the Technical University in Munich. In 3 out of 31 patients treated by retinoids on a long-term basis, skeletal changes were found radiologically as a result of the retinoid medication.

Monitoring the long term vegetation phenology change in Northeast China from 1982 to 2015.

Science.gov (United States)

Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yan, Fengqin; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

2017-11-07

Global warming has contributed to the extension of the growing season in North Hemisphere. In this paper, we investigated the spatial characteristics of the date of the start of the season (SOS), the date of the end of the season (EOS) and the length of the season (LOS) and their change trends from 1982 to 2015 in Northeast China. Our results showed that there was a significant advance of SOS and a significant delay of EOS, especially in the north part of Northeast China. For the average change slope of EOS in the study area, the delay trend was 0.25 d/y, which was more obvious than the advance trend of -0.13 d/y from the SOS. In particular, the LOS of deciduous needleleaf forest (DNF) and grassland increased with a trend of 0.63 d/y and 0.66 d/y from 1982 to 2015, indicating the growth season increased 21.42 and 22.44 days in a 34-year period, respectively. However, few negative signals were detected nearby Hulun Lake, suggesting that the continuous climate warming in the future may bring no longer growing periods for the grass in the semiarid areas as the drought caused by climate warming may limit the vegetation growth.

What are driving the long-term Caspian Sea level change?

Science.gov (United States)

Chen, J.

2017-12-01

Caspian Sea level (CSL) has undergone substantial fluctuations during the past several hundred years. The causes over the entire historical period are uncertain, but we investigate here large changes seen in the past several decades. We use climate model predicted precipitation (P), evaporation (E), and observed river runoff (R) to reconstruct long-term CSL changes for 1979-2015, and show that PER (P-E+R) flux predictions agree very well with observed CSL changes. The observed rapid CSL increase (about 12.74 cm/yr) and significant drop ( -6.72 cm/yr) during the periods 1979-1995 and 1996-2015 are well accounted for by integrated PER flux predictions of +12.38 and -6.79 cm/yr, respectively. We show that increased evaporation rates over the Caspian Sea play a dominant role in reversing the increasing trend in CSL during the past 37 years. The current long-term decline in CSL is expected to continue into the foreseeable future, under global warming scenarios.

Changes of the eye during long-term spaceflight. Review

Directory of Open Access Journals (Sweden)

I. A. Makarov

2016-01-01

Full Text Available The review includes the publications of the scientific literature on the eye change during long-term spaceflight. The any eye changes such as visual impairment, hyperopic shift in refraction, changes in the intraocular pressure, increased the intracranial pressure, globe flattening, choroidal folding, optic disc edema, and optic nerve kinking and other changes were reported. The main cause of eye disorders, in all probability, is the increase of the intracranial pressure during long-term spaceflight. The reasons of the increased intracranial pressure are a collection of various factors of adaptation mechanisms in the body to weightless conditions. The leading role in the development of intracranial hypertension takes a redistribution of the body fluids (blood and lymph in the direction of the head, but the opportunities and the effect of other factors are present. Also the displacement and increase of the internal organs volume of the chest can cause external compression of the jugular veins, increasing the pressure of the blood in them, and as the result to lead to the increase of the intracranial pressure. The role of trigger such mechanisms in the development of the intracranial hypertension in the microgravity environment as anatomical predisposition of the body, race, metabolic changes under the influence of high carbon dioxide content in the different compartments of the station, high sodium intake, the enzyme dysfunction, weight exercises of the astronauts was discussed. However, the pathogenic mechanisms is currently still under investigation. An important role in the study of the adaptation mechanisms is given to research not only before and after the flight, but also during the space flight. The accumulated knowledge and experience about the changes in organs and systems in the conditions of human adaptation to microgravity will help answer many questions related to the implementation of the long spaceflights.

Long-Term Soil Chemistry Changes in Aggrading Forest Ecosystems

Science.gov (United States)

Jennifer D. Knoepp; Wayne T. Swank

1994-01-01

Assessing potential long-term forest productivity requires identification of the processes regulating chemical changes in forest soils. We resampled the litter layer and upper two mineral soil horizons, A and AB/BA, in two aggrading southern Appalachian watersheds 20 yr after an earlier sampling. Soils from a mixed-hardwood watershed exhibited a small but significant...

Long-term fundus changes in acquired partial lipodystrophy.

Science.gov (United States)

Jansen, Joyce; Delaere, Lien; Spielberg, Leigh; Leys, Anita

2013-11-18

We describe long-term fundus changes in a patient with partial lipodystrophy (PL). Retinal pigment alterations, drusen and subretinal neovascularisation were seen without evidence for membranoproliferative glomerulonephritis. Fundus alterations similar to those seen in age-related macular degeneration can occur at an earlier age in patients with PL, even without renal disease. Dysregulation of an alternative complement pathway with low serum levels of C3 has been implicated as a pathogenetic mechanism.

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

Science.gov (United States)

Yiqi Luo; Jerry Melillo; Shuli Niu; Claus Beier; James S. Clark; Aime E.T. Classen; Eric Dividson; Jeffrey S. Dukes; R. Dave Evans; Christopher B. Field; Claudia I. Czimczik; Michael Keller; Bruce A. Kimball; Lara M. Kueppers; Richard J. Norby; Shannon L. Pelini; Elise Pendall; Edward Rastetter; Johan Six; Melinda Smith; Mark G. Tjoelker; Margaret S. Torn

2011-01-01

Many serious ecosystem consequences of climate change will take decades or even centuries to emerge. Long-term ecological responses to global change are strongly regulated by slow processes, such as changes in species composition, carbon dynamics in soil and by long-lived plants, and accumulation of nutrient capitals. Understanding and predicting these processes...

Radiological features of osteoarticular changes in long-term (15 years) hemodialysis patients

International Nuclear Information System (INIS)

Orzincolo, C.; Ghedini, M.; Cardona, P.; Bedani, P.L.; Storari, A.; Scutellari, P.N.; Cavallari, L.

1991-01-01

Osteoarticular complications, which are characterized by osseous pain, pathologic fractures, and decreased articular mobility, represent one of the mayor problems affecting long-term (over 15 years) hemodialysis patients. These changes seem to have a multifactorial etiology; they include osteomalacia, secondary hyperparathyroidism, and dialysis-related amyloidosis. Ten patients (5 males and 5 females, mean age 55± 7 years) on long-term (over 15 years) hemodialysis were submitted to X-ray examinations of the skull, spine, shoulders, wrists, pelvis, and knees. Serum calcium, phosphorous, parathyroid hormone, alkaline phosphatase, and basal aluminium levels were also calculated. Osteopenia was demonstrated in all patients. Seven of them had alterations due to hyperparathyroidism. Six patients exhibited signs related to dialysis spondyloarthropathy; in 9 cases amyloid lesions, geodes, and erosions were present in wrists, humeral heads, or hips. One patients exhibited osteomalacic changes. Most long-terms dialysis patients presented multifactorial osteoarticular changes due to hyperparathyroidism, osteomalacia and dialysis-related amyloidosis. Clinical sympoms and decreased articular mobility appeared to be due mainly to amyloid osteoarthropathy

Vegetation dynamics of the Tanbi Wetland National Park, The Gambia

Science.gov (United States)

Ceesay, A.

2016-12-01

Changes in mangrove vegetation have been identified as an important indicator of environmental change. The mangroves of the Tanbi Wetland National Park (TWNP) connect the Atlantic coast with the estuary of the River Gambia and as such, play an invaluable role in the agriculture, tourism and fisheries sectors of The Gambia. Our research seeks to understand the long-term changes in the mangrove vegetation to strengthen the formulation of sustainable alternative livelihoods and adaptation strategies to climate change. Mangrove vegetation dynamics was assessed by remote sensing, using decadal Landsat images covering 1973 - 2012. Physicochemical parameters were analyzed during the rainy and dry seasons of The Gambia for correlation with climate data. Our findings indicate that the long-term changes in salinity (24.5 and 35.8ppt) and water temperature (27.6oC and 30.2oC) during the rainy and dry seasons respectively are retarding mangrove growth. Mangrove vegetation cover declined by 6%, while grassland increased by 56.4%. This research concludes that long-term hyper-salinity is the cause for the stunted vegetation and lack of mangrove rejuvenation. We propose that specialized replanting systems such as the use of saplings be adopted instead of the conventional use of propagules. Alternative livelihoods also need to be diversified to support coastal communities.

Long-term effects of climate change on Europe's water resources

NARCIS (Netherlands)

Domnisoru, A.

2006-01-01

Climate variations from last century show a global warming trend. Evidence from the past reveals that the anthropogenic greenhouse effect caused changes in climate parameters (temperature, precipitation and evaporation) at the European scale as well. On long-term this might have essential impact on

Long-term stabilization of uranium mill tailings

International Nuclear Information System (INIS)

Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

1984-01-01

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are (1) rock cover, (2) soil and revegetation, or (3) a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%. For these steeper slopes, the use of rock talus or riprap will be necessary to maximize the probability of long-term stability. The use of vegetation to control erosion on the flatter portions of the site may be practicable in regions of the USA with sufficient rainfall and suitable soil types, but revegetation practices must be carefully evaluated to ensure that long-term

Long-term effects of seeding after wildfire on vegetation in Great Basin shrubland ecosystems

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Knutson, Kevin C.; Pyke, David A.; Wirth, Troy A.; Arkle, Robert S.; Pilliod, David S.; Brooks, Matthew L.; Chambers, Jeanne C.; Grace, James B.

2014-01-01

1. Invasive annual grasses alter fire regimes in shrubland ecosystems of the western USA, threatening ecosystem function and fragmenting habitats necessary for shrub-obligate species such as greater sage-grouse. Post-fire stabilization and rehabilitation treatments have been administered to stabilize soils, reduce invasive species spread and restore or establish sustainable ecosystems in which native species are well represented. Long-term effectiveness of these treatments has rarely been evaluated. 2. We studied vegetation at 88 sites where aerial or drill seeding was implemented following fires between 1990 and 2003 in Great Basin (USA) shrublands. We examined sites on loamy soils that burned only once since 1970 to eliminate confounding effects of recurrent fire and to assess soils most conducive to establishment of seeded species. We evaluated whether seeding provided greater cover of perennial seeded species than burned–unseeded and unburned–unseeded sites, while also accounting for environmental variation. 3. Post-fire seeding of native perennial grasses generally did not increase cover relative to burned–unseeded areas. Native perennial grass cover did, however, increase after drill seeding when competitive non-natives were not included in mixes. Seeding non-native perennial grasses and the shrub Bassia prostrata resulted in more vegetative cover in aerial and drill seeding, with non-native perennial grass cover increasing with annual precipitation. Seeding native shrubs, particularly Artemisia tridentata, did not increase shrub cover or density in burned areas. Cover of undesirable, non-native annual grasses was lower in drill seeded relative to unseeded areas, but only at higher elevations. 4. Synthesis and applications. Management objectives are more likely to be met in high-elevation or precipitation locations where establishment of perennial grasses occurred. On lower and drier sites, management objectives are unlikely to be met with seeding alone

Long-term monitoring of change in Tropical grasslands- GLORIA network in the Andes

Science.gov (United States)

Cuesta, F. X.; Muriel, P.; Halloy, S.; Beck, S.; Meneses, R. I.; Irazabal, J.; Aguirre, N.; Viñas, P.; Suarez, D.; Becerra, M. T.; Gloria-Andes Network

2013-05-01

It has been shown that predicted warming and increased frequency of extreme weather events increase with altitude in the Andean mountains. Combined with enormous topographic (and hence precipitation) heterogeneity, poverty and intensive land use, creates in the region a situation of high vulnerability to global change. Since 2005 the network Global Research Initiative in Alpine Environment (GLORIA) sites have been progressively installed in Andean countries to monitor changes, document the type and magnitude of impacts and provide guidance to develop adaptation strategies for biodiversity, humans, and productive systems. We report the preliminary results from 10 of those sites, in addition to new sites planned in South America. These sites provide baseline data and identify processes and patterns in plant biodiversity across different geographic contexts. These preliminary results show the tremendous singularity of the vegetation and flora patterns in the study sites, suggesting high sensitivity of these ecosystems to climate anomalies. It is expected that the consolidation of this network will support and strengthen long-term observation and monitoring research programs to enable the documentation and understanding of climate change impacts on the Andean biota. Our research considers complementary modules of investigation (e.g. carbon stocks and fluxes, plant responses to experimental manipulation) that contextualize the challenges and opportunities of adaptation for biodiversity and socio-economic components, providing measures of trends as well as effectiveness of adaptive management strategies.

The changing flow of management information systems in long-term care facilities.

Science.gov (United States)

Stokes, D F

1997-08-01

Over the past three decades, the long-term care community has seen continual increases in the complexity and sophistication of management information systems. These changes have been brought about by the ever-increasing demands on owners and managers to provide accurate and timely data to both regulators and financial investors. The evolution of these systems has increased rapidly in recent years as the nation attempts to reinvent the funding mechanisms for long-term care.

Responses of Vegetation Cover to Environmental Change in Large Cities of China

Directory of Open Access Journals (Sweden)

Kai Jin

2018-01-01

Full Text Available Vegetation cover is crucial for the sustainability of urban ecosystems; however, this cover has been undergoing substantial changes in cities. Based on climate data, city statistical data, nighttime light data and the Normalized Difference Vegetation Index (NDVI dataset, we investigate the spatiotemporal variations of climate factors, urban lands and vegetation cover in 71 large cities of China during 1998–2012, and explore their correlations. A regression model between growing-season NDVI (G-NDVI and urban land proportion (PU is built to quantify the impact of urbanization on vegetation cover change. The results indicate that the spatiotemporal variations of temperature, precipitation, PU and G-NDVI are greatly different among the 71 cities which experienced rapid urbanization. The spatial difference of G-NDVI is closely related to diverse climate conditions, while the inter-annual variations of G-NDVI are less sensitive to climate changes. In addition, there is a negative correlation between G-NDVI trend and PU change, indicating vegetation cover in cities have been negatively impacted by urbanization. For most of the inland cities, the urbanization impacts on vegetation cover in urban areas are more severe than in suburban areas. But the opposite occurs in 17 cities mainly located in the coastal areas which have been undergoing the most rapid urbanization. Overall, the impacts of urbanization on G-NDVI change are estimated to be −0.026 per decade in urban areas and −0.015 per decade in suburban areas during 1998–2012. The long-term developments of cities would persist and continue to impact on the environmental change and sustainability. We use a 15-year window here as a case study, which implies the millennia of human effects on the natural biotas and warns us to manage landscapes and preserve ecological environments properly.

Patterns of Change in Interpersonal Problems During and After Short-term and Long-term Psychodynamic Group Therapy: A Randomized Clinical Trial.

Science.gov (United States)

Fjeldstad, Anette; Høglend, Per; Lorentzen, Steinar

2017-05-01

In this study, we compared the patterns of change in interpersonal problems between short-term and long-term psychodynamic group therapy. A total of 167 outpatients with mixed diagnoses were randomized to 20 or 80 weekly sessions of group therapy. Interpersonal problems were assessed with the Inventory of Interpersonal Problems at six time points during the 3-year study period. Using linear mixed models, change was linearly modelled in two steps. Earlier (within the first 6 months) and later (during the last 2.5 years) changes in five subscales were estimated. Contrary to what we expected, short-term therapy induced a significantly larger early change than long-term therapy on the cold subscale and there was a trend on the socially avoidant subscale, using a Bonferroni-adjusted alpha. There was no significant difference between short-term and long-term group therapy for improving problems in the areas cold, socially avoidant, nonassertive, exploitable, and overly nurturant over the 3 years.

Target-Dependent Structural Changes Accompanying Long-Term Synaptic Facilitation in Aplysia Neurons

Science.gov (United States)

Glanzman, David L.; Kandel, Eric R.; Schacher, Samuel

1990-08-01

The mechanisms underlying structural changes that accompany learning and memory have been difficult to investigate in the intact nervous system. In order to make these changes more accessible for experimental analysis, dissociated cell culture and low-light-level video microscopy were used to examine Aplysia sensory neurons in the presence or absence of their target cells. Repeated applications of serotonin, a facilitating transmitter important in behavioral dishabituation and sensitization, produced growth of the sensory neurons that paralleled the long-term enhancement of synaptic strength. This growth required the presence of the postsynaptic motor neuron. Thus, both the structural changes and the synaptic facilitation of Aplysia sensorimotor synapses accompanying long-term behavioral sensitization can be produced in vitro by applying a single facilitating transmitter repeatedly. These structural changes depend on an interaction of the presynaptic neuron with an appropriate postsynaptic target.

Long-term changes in the surface conditions of PLT

International Nuclear Information System (INIS)

Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Picraux, S.T.; Borders, J.A.; Magee, C.W.

1977-01-01

Long-term changes in the surface conditions of the PLT vacuum vessel wall have been monitored by the periodic analysis of a variety of sample substrates (stainless steel, alumina, silicon), exposed to PLT discharges for periods of up to several months and subsequently removed for analysis by Auger electron spectroscopy (AES), photoelectron spectroscopy, ion backscattering, nuclear reaction analysis, secondary ion mass spectroscopy, and scanning electron microscopy

The long-term Global LAnd Surface Satellite (GLASS) product suite and applications

Science.gov (United States)

Liang, S.

2015-12-01

Our Earth's environment is experiencing rapid changes due to natural variability and human activities. To monitor, understand and predict environment changes to meet the economic, social and environmental needs, use of long-term high-quality satellite data products is critical. The Global LAnd Surface Satellite (GLASS) product suite, generated at Beijing Normal University, currently includes 12 products, including leaf area index (LAI), broadband shortwave albedo, broadband longwave emissivity, downwelling shortwave radiation and photosynthetically active radiation, land surface skin temperature, longwave net radiation, daytime all-wave net radiation, fraction of absorbed photosynetically active radiation absorbed by green vegetation (FAPAR), fraction of green vegetation coverage, gross primary productivity (GPP), and evapotranspiration (ET). Most products span from 1981-2014. The algorithms for producing these products have been published in the top remote sensing related journals and books. More and more applications have being reported in the scientific literature. The GLASS products are freely available at the Center for Global Change Data Processing and Analysis of Beijing Normal University (http://www.bnu-datacenter.com/), and the University of Maryland Global Land Cover Facility (http://glcf.umd.edu). After briefly introducing the basic characteristics of GLASS products, we will present some applications on the long-term environmental changes detected from GLASS products at both global and local scales. Detailed analysis of regional hotspots, such as Greenland, Tibetan plateau, and northern China, will be emphasized, where environmental changes have been mainly associated with climate warming, drought, land-atmosphere interactions, and human activities.

Implementing culture change in long-term dementia care settings.

Science.gov (United States)

McGreevy, Jessica

2016-01-06

The approach to nursing in long-term care settings for people living with dementia continues to evolve from a traditional, task-oriented culture to one that is person-centred. Such change can be difficult to manage and may encounter considerable opposition; having an understanding of change management and leadership styles may help to make this transition easier. This article discusses the differences between task-oriented and person-centred care, theories of management, motivation and leadership styles, and focuses on those that are most appropriate for this type of change. An improved understanding of these theories will enable nurses to support others in the delivery of person-centred care.

Non-climatic factors and long-term, continental-scale changes in seasonally frozen ground

Science.gov (United States)

Shiklomanov, Nikolay I.

2012-03-01

). In their recent paper entitled 'An observational 71-year history of seasonally frozen ground changes in Eurasian high latitudes', Frauenfeld and Zhang (2011) provided detailed analysis of soil temperature data to assess 1930-2000 trends in seasonal freezing depth. The data were obtained from 387 Soviet non-permafrost meteorological stations. The authors performed systematic, quality-controlled, integrative analysis over the entire former Soviet Union domain. The long-term changes in depth of seasonal freezing were discussed in relation to such forcing variables as air temperature, degree days of freezing/thawing, snow depth and summer precipitation as well as modes of the North Atlantic Oscillation. The spatially average approach adopted for the study provides a generalized continental-scale trend. The study greatly improves, expands and extends previous 1956-90 analysis of the ground thermal regime over the Eurasian high latitudes (Frauenfeld et al 2004). Although the work of Frauenfeld and Zhang (2011) is the most comprehensive assessment of the continental-scale long-term trends in seasonal freezing available to date, more detailed analysis is needed to determine the effect of climate change on seasonally frozen ground. It should be noted that, in addition to the variables considered for analysis, other non-climatic factors affect the depth of freezing propagation. Unlike the surface, which is influenced by the climate directly, the ground even at shallow depth receives a climatic signal that is substantially modified by edaphic processes, contributing to highly localized thermal sensitivities of the ground to climatic forcing. Subsurface properties, soil moisture, and snow and vegetation covers influence the depth of freezing. Topography also plays an important role in establishing the ground thermal regime. It is an important determinant of the amount of heat received by the ground surface, affects the distribution of snow and vegetation, and influences the

Fire and vegetation history on Santa Rosa Island, Channel Islands, and long-term environmental change in southern California

Science.gov (United States)

Starratt, Scott W.; Pinter, N.; Anderson, Robert S.; Jass, R.B.

2009-01-01

The long-term history of vegetation and fire was investigated at two locations – Soledad Pond (275 m; from ca. 12 000 cal. a BP) and Abalone Rocks Marsh (0 m; from ca. 7000 cal. a BP) – on Santa Rosa Island, situated off the coast of southern California. A coastal conifer forest covered highlands of Santa Rosa during the last glacial, but by ca. 11 800 cal. a BP Pinus stands, coastal sage scrub and grassland replaced the forest as the climate warmed. The early Holocene became increasingly drier, particularly after ca. 9150 cal. a BP, as the pond dried frequently, and coastal sage scrub covered the nearby hillslopes. By ca. 6900 cal. a BP grasslands recovered at both sites. Pollen of wetland plants became prominent at Soledad Pond after ca. 4500 cal. a BP, and at Abalone Rocks Marsh after ca. 3465 cal. a BP. Diatoms suggest freshening of the Abalone Rocks Marsh somewhat later, probably by additional runoff from the highlands. Introduction of non-native species by ranchers occurred subsequent to AD 1850. Charcoal influx is high early in the record, but declines during the early Holocene when minimal biomass suggests extended drought. A general increase occurs after ca. 7000 cal. a BP, and especially after ca. 4500 cal. a BP. The Holocene pattern closely resembles population levels constructed from the archaeological record, and suggests a potential influence by humans on the fire regime of the islands, particularly during the late Holocene.

Changes in northeast African hydrology and vegetation associated with Pliocene–Pleistocene sapropel cycles

Science.gov (United States)

Rose, Cassaundra; Polissar, Pratigya J.; Tierney, Jessica E.; Filley, Timothy

2016-01-01

East African climate change since the Late Miocene consisted of persistent shorter-term, orbital-scale wet–dry cycles superimposed upon a long-term trend towards more open, grassy landscapes. Either or both of these modes of palaeoclimate variability may have influenced East African mammalian evolution, yet the interrelationship between these secular and orbital palaeoclimate signals remains poorly understood. Here, we explore whether the long-term secular climate change was also accompanied by significant changes at the orbital-scale. We develop northeast African hydroclimate and vegetation proxy data for two 100 kyr-duration windows near 3.05 and 1.75 Ma at ODP Site 967 in the eastern Mediterranean basin, where sedimentation is dominated by eastern Sahara dust input and Nile River run-off. These two windows were selected because they have comparable orbital configurations and bracket an important increase in East African C4 grasslands. We conducted high-resolution (2.5 kyr sampling) multiproxy biomarker, H- and C-isotopic analyses of plant waxes and lignin phenols to document orbital-scale changes in hydrology, vegetation and woody cover for these two intervals. Both intervals are dominated by large-amplitude, precession-scale (approx. 20 kyr) changes in northeast African vegetation and rainfall/run-off. The δ13Cwax values and lignin phenol composition record a variable but consistently C4 grass-dominated ecosystem for both intervals (50–80% C4). Precessional δDwax cycles were approximately 20–30‰ in peak-to-peak amplitude, comparable with other δDwax records of the Early Holocene African Humid Period. There were no significant differences in the means or variances of the δDwax or δ13Cwax data for the 3.05 and 1.75 Ma intervals studied, suggesting that the palaeohydrology and palaeovegetation responses to precessional forcing were similar for these two periods. Data for these two windows suggest that the eastern Sahara did not experience the

Long-term potentiation and long-term depression: a clinical perspective

Directory of Open Access Journals (Sweden)

Timothy V.P. Bliss

2011-01-01

Full Text Available Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke.

Long-term potential and actual evapotranspiration of two different forests on the Atlantic Coastal Plain

Science.gov (United States)

Devendra Amatya; S. Tian; Z. Dai; Ge Sun

2016-01-01

A reliable estimate of potential evapotranspiration (PET) for a forest ecosystem is critical in ecohydrologic modeling related with water supply, vegetation dynamics, and climate change and yet is a challenging task due to its complexity. Based on long-term on-site measured hydro-climatic data and predictions from earlier validated hydrologic modeling studies...

Exploring the Future of Fuel Loads in Tasmania, Australia: Shifts in Vegetation in Response to Changing Fire Weather, Productivity, and Fire Frequency

Directory of Open Access Journals (Sweden)

Rebecca Mary Bernadette Harris

2018-04-01

Full Text Available Changes to the frequency of fire due to management decisions and climate change have the potential to affect the flammability of vegetation, with long-term effects on the vegetation structure and composition. Frequent fire in some vegetation types can lead to transformational change beyond which the vegetation type is radically altered. Such feedbacks limit our ability to project fuel loads under future climatic conditions or to consider the ecological tradeoffs associated with management burns. We present a “pathway modelling” approach to consider multiple transitional pathways that may occur under different fire frequencies. The model combines spatial layers representing current and future fire danger, biomass, flammability, and sensitivity to fire to assess potential future fire activity. The layers are derived from a dynamically downscaled regional climate model, attributes from a regional vegetation map, and information about fuel characteristics. Fire frequency is demonstrated to be an important factor influencing flammability and availability to burn and therefore an important determinant of future fire activity. Regional shifts in vegetation type occur in response to frequent fire, as the rate of change differs across vegetation type. Fire-sensitive vegetation types move towards drier, more fire-adapted vegetation quickly, as they may be irreversibly impacted by even a single fire, and require very long recovery times. Understanding the interaction between climate change and fire is important to identify appropriate management regimes to sustain fire-sensitive communities and maintain the distribution of broad vegetation types across the landscape.

The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought

KAUST Repository

Meng, X. H.; Evans, J. P.; McCabe, Matthew

2014-01-01

Simulated feedbacks between vegetation fraction, soil moisture, and drought over southeast Australia were also investigated. Results indicate that vegetation fraction changes lag precipitation reductions by 6–8 months in nonarid regions. With the onset of the 2002 drought, a potential fast physical mechanism was found to play a positive role in the soil moisture–precipitation feedback, while a slow biological mechanism provides a negative feedback in the soil moisture–precipitation interaction on a longer time scale. That is, in the short term, a reduction in soil moisture leads to a reduction in the convective potential and, hence, precipitation, further reducing the soil moisture. If low levels of soil moisture persist long enough, reductions in vegetation cover and vigor occur, reducing the evapotranspiration and thus reducing the soil moisture decreases and dampening the fast physical feedback. Importantly, it was observed that these feedbacks are both space and time dependent.

Medium- and Long-term Prediction of LOD Change with the Leap-step Autoregressive Model

Science.gov (United States)

Liu, Q. B.; Wang, Q. J.; Lei, M. F.

2015-09-01

It is known that the accuracies of medium- and long-term prediction of changes of length of day (LOD) based on the combined least-square and autoregressive (LS+AR) decrease gradually. The leap-step autoregressive (LSAR) model is more accurate and stable in medium- and long-term prediction, therefore it is used to forecast the LOD changes in this work. Then the LOD series from EOP 08 C04 provided by IERS (International Earth Rotation and Reference Systems Service) is used to compare the effectiveness of the LSAR and traditional AR methods. The predicted series resulted from the two models show that the prediction accuracy with the LSAR model is better than that from AR model in medium- and long-term prediction.

Transformative art: art as means for long-term neurocognitive change.

Science.gov (United States)

Preminger, Son

2012-01-01

Every artwork leads to a unique experience by the observer or participant, may it be sensory, emotional, cognitive, interactive, or spiritual experience. At the neurobiological level, such experiences are manifested as activation of the corresponding neural networks. Neuroscience has demonstrated that experience, in particular repeated experience, can cause a long-term change in the involved brain circuits (experience-dependent plasticity). This review will discuss the molding and transformative aspect of arts, examining how repeated and on-going experience of arts may alter cognitive, emotional, and behavioral patterns as well as their underlying neural circuits. The application of this approach to cognitive training and neuropsychological rehabilitation methods will be addressed as well. In addition, it will be suggested that this approach to art, as a long-term transformative medium, may lead to a novel viewpoint on art and a different approach to its creation. Artists can design artworks that aspire to form, in addition to one-shot influencing experience, on-going experiences which gradually create a lasting change, possibly improving audiences' neuropsychological functions.

Transformative Art:Art as Means for Long-term Neurocognitive Change

Directory of Open Access Journals (Sweden)

Son ePreminger

2012-04-01

Full Text Available Every artwork leads to a unique experience by the observer or participant, may it be sensory, emotional, cognitive, interactive or spiritual experience. At the neurobiological level, such experiences are manifested as activation of the corresponding neural networks. Neuroscience has demonstrated that experience, in particular repeated experience, can cause a long-term change in the involved brain circuits (experience-dependent plasticity. This review will discuss the molding and transformative aspect of arts, examining how repeated and on-going experience of arts may alter cognitive, emotional and behavioral patterns as well as their underlying neural circuits. The application of this approach to cognitive training and neuropsychological rehabilitation methods will be addressed as well. In addition, it will be suggested that this approach to art, as long-term transformative, may lead to a novel viewpoint on art and a different approach to its creation. Artists can design artworks that aspire to form, in addition to one-shot influencing experience, on-going experiences which gradually create a lasting change, possibly improving audiences' neuropsychological functions.

Near-Term Actions to Address Long-Term Climate Risk

Science.gov (United States)

Lempert, R. J.

2014-12-01

Addressing climate change requires effective long-term policy making, which occurs when reflecting on potential events decades or more in the future causes policy makers to choose near-term actions different than those they would otherwise pursue. Contrary to some expectations, policy makers do sometimes make such long-term decisions, but not as commonly and successfully as climate change may require. In recent years however, the new capabilities of analytic decision support tools, combined with improved understanding of cognitive and organizational behaviors, has significantly improved the methods available for organizations to manage longer-term climate risks. In particular, these tools allow decision makers to understand what near-term actions consistently contribute to achieving both short- and long-term societal goals, even in the face of deep uncertainty regarding the long-term future. This talk will describe applications of these approaches for infrastructure, water, and flood risk management planning, as well as studies of how near-term choices about policy architectures can affect long-term greenhouse gas emission reduction pathways.

Effects of organic matter removal, soil compaction, and vegetation control on 5-year seedling performance: a regional comparison of long-term soil productivity sites

Science.gov (United States)

Robert L. Fleming; Robert F. Powers; Neil W. Foster; J. Marty Kranabetter; D. Andrew Scott; Felix Jr. Ponder; Shannon Berch; William K. Chapman; Richard D. Kabzems; Kim H. Ludovici; David M. Morris; Deborah S. Page-Dumroese; Paul T. Sanborn; Felipe G. Sanchez; Douglas M. Stone; Allan E. Tiarks

2006-01-01

We examined fifth-year seedling response to soil disturbance and vegetation control at 42 experimental locations representing 25 replicated studies within the North American Long-Term Soil Productivity (LTSP) program. These studies share a common experimental design while encompassing a wide range of climate, site conditions, and forest types. Whole-tree harvest had...

Global variation in the long-term seasonal changes observed in ionospheric F region data

Directory of Open Access Journals (Sweden)

C. J. Scott

2015-04-01

Full Text Available Long-term variability has previously been observed in the relative magnitude of annual and semi-annual variations in the critical frequency (related to the peak electron concentration of the ionospheric F2 layer (foF2. In this paper we investigate the global patterns in such variability by calculating the time varying power ratio of semi-annual to annual components seen in ionospheric foF2 data sequences from 77 ionospheric monitoring stations around the world. The temporal variation in power ratios observed at each station was then correlated with the same parameter calculated from similar epochs for the Slough/Chilton data set (for which there exists the longest continuous sequence of ionospheric data. This technique reveals strong regional variation in the data, which bears a striking similarity to the regional variation observed in long-term changes to the height of the ionospheric F2 layer. We argue that since both the height and peak density of the ionospheric F2 region are influenced by changes to thermospheric circulation and composition, the observed long-term and regional variability can be explained by such changes. In the absence of long-term measurements of thermospheric composition, detailed modelling work is required to investigate these processes.

How Do You Motivate Long-Term Behavior Change to Prevent Cancer?

Science.gov (United States)

John P. Pierce PhD, a professor in the Department of Family and Preventive Medicine at the University of California, San Diego and Director of Population Science at Moores Cancer Center, presented "How Do You Motivate Long-Term Behavior Change to Prevent Cancer?" 

Structural change of the economy, technological progress and long-term energy demand

International Nuclear Information System (INIS)

Klinge Jacobsen, H.

2000-01-01

The material included in the report is a collection of papers dealing with different issues related to the topics included in the title. Some of these papers have already either been published or presented at various conferences. Together with a general introduction, they constitute the author's PhD dissertation. The dissertation includes six papers and two shorter notes on different aspects of structural change of the economy and energy demand. Three different issues related to long-term energy demand are discussed: (1) the importance of technological change and its representation in energy-economy modelling, (2) an integration of two different modelling approaches, and (3) the effect on energy demand of structural changes exemplified by changes in the energy supply sector and in Danish trade patterns. The report highlights a few aspects of the interaction between structural economic changes and energy demand, but it does not intend to cover a wide range of issues related to these topics. In the introductory chapter some discussions and thoughts about issues not covered by the articles are brought forward. The introductory chapter includes an overview of possible relations between longterm energy demand and the economy, technical progress demography, social conditions and politics. The first two papers discuss the importance for projections of long-term energy demand of the way in which technological progress is modelled. These papers focus on energy-economy modelling. A paper dealing with two different approaches to energy demand modelling and the possible integration of these approaches in the Danish case follows next. The integrated Danish model, is then used for analysing different revenue recycling principles in relation to a CO 2 tax. The effect of subsidising biomass use is compared with recycling through corporate tax rates. Then a paper follows describing the structural change of a specific sector, namely the energy supply sector, and the implications for

Long-term change of activity of very low-frequency earthquakes in southwest Japan

Science.gov (United States)

Baba, S.; Takeo, A.; Obara, K.; Kato, A.; Maeda, T.; Matsuzawa, T.

2017-12-01

On plate interface near seismogenic zone of megathrust earthquakes, various types of slow earthquakes were detected including non-volcanic tremors, slow slip events (SSEs) and very low-frequency earthquakes (VLFEs). VLFEs are classified into deep VLFEs, which occur in the downdip side of the seismogenic zone, and shallow VLFEs, occur in the updip side, i.e. several kilometers in depth in southwest Japan. As a member of slow earthquake family, VLFE activity is expected to be a proxy of inter-plate slipping because VLFEs have the same mechanisms as inter-plate slipping and are detected during Episodic tremor and slip (ETS). However, long-term change of the VLFE seismicity has not been well constrained compared to deep low-frequency tremor. We thus studied long-term changes in the activity of VLFEs in southwest Japan where ETS and long-term SSEs have been most intensive. We used continuous seismograms of F-net broadband seismometers operated by NIED from April 2004 to March 2017. After applying the band-pass filter with a frequency range of 0.02—0.05 Hz, we adopted the matched-filter technique in detecting VLFEs. We prepared templates by calculating synthetic waveforms for each hypocenter grid assuming typical focal mechanisms of VLFEs. The correlation coefficients between templates and continuous F-net seismograms were calculated at each grid every 1s in all components. The grid interval is 0.1 degree for both longitude and latitude. Each VLFE was detected as an event if the average of correlation coefficients exceeds the threshold. We defined the detection threshold as eight times as large as the median absolute deviation of the distribution. At grids in the Bungo channel, where long-term SSEs occurred frequently, the cumulative number of detected VLFEs increases rapidly in 2010 and 2014, which were modulated by stress loading from the long-term SSEs. At inland grids near the Bungo channel, the cumulative number increases steeply every half a year. This stepwise

Social Stairs : taking the Piano Staircase towards long-term behavioral change

NARCIS (Netherlands)

Peeters, M.M.R.; Megens, C.J.P.G.; Hoven, van den E.A.W.H.; Hummels, C.C.M.; Brombacher, A.C.; Berkovsky, S.; Freyne, J.

2013-01-01

This paper addresses the development of Social Stairs, an intelligent musical staircase to change people’s behavior in the long-term to take the stairs in favor of the elevator. Through designing with the Experiential Design Landscape (EDL) method, a design opportunity was found that social

Climate change-induced vegetation change as a driver of increased subarctic biogenic volatile organic compound emissions.

Science.gov (United States)

Valolahti, Hanna; Kivimäenpää, Minna; Faubert, Patrick; Michelsen, Anders; Rinnan, Riikka

2015-09-01

Emissions of biogenic volatile organic compounds (BVOCs) have been earlier shown to be highly temperature sensitive in subarctic ecosystems. As these ecosystems experience rapidly advancing pronounced climate warming, we aimed to investigate how warming affects the BVOC emissions in the long term (up to 13 treatment years). We also aimed to assess whether the increased litterfall resulting from the vegetation changes in the warming subarctic would affect the emissions. The study was conducted in a field experiment with factorial open-top chamber warming and annual litter addition treatments on subarctic heath in Abisko, northern Sweden. After 11 and 13 treatment years, BVOCs were sampled from plant communities in the experimental plots using a push-pull enclosure technique and collection into adsorbent cartridges during the growing season and analyzed with gas chromatography-mass spectrometry. Plant species coverage in the plots was analyzed by the point intercept method. Warming by 2 °C caused a 2-fold increase in monoterpene and 5-fold increase in sesquiterpene emissions, averaged over all measurements. When the momentary effect of temperature was diminished by standardization of emissions to a fixed temperature, warming still had a significant effect suggesting that emissions were also indirectly increased. This indirect increase appeared to result from increased plant coverage and changes in vegetation composition. The litter addition treatment also caused significant increases in the emission rates of some BVOC groups, especially when combined with warming. The combined treatment had both the largest vegetation changes and the highest BVOC emissions. The increased emissions under litter addition were probably a result of a changed vegetation composition due to alleviated nutrient limitation and stimulated microbial production of BVOCs. We suggest that the changes in the subarctic vegetation composition induced by climate warming will be the major factor

Monitoring temporal Vegetation changes in Lao tropical forests

International Nuclear Information System (INIS)

Phompila, Chittana; Lewis, Megan; Clarke, Kenneth; Ostendorf, Bertram

2014-01-01

Studies on changes in vegetation are essential for understanding the interaction between humans and the environment. These studies provide key information for land use assessment, terrestrial ecosystem monitoring, carbon flux modelling and impacts of global climate change. The primary purpose of this study was to detect temporal vegetation changes in tropical forests in the southern part of Lao PDR from 2001-2012. The study investigated the annual vegetation phenological response of dominant land cover types across the study area and relationships to seasonal precipitation and temperature. Improved understanding of intra-annual patterns of vegetation variation was useful to detect longer term changes in vegetation. The breaks for additive season and trend (BFAST) approach was implemented to detect changes in these land cover types throughout the 2001-2012 period. We used the enhanced vegetation index (EVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) (MOD13Q1 products) and monthly rainfall and temperature data obtained from the Meteorology and Hydrology Department, Ministry of Agriculture-Forestry, published by Lao National Statistical Centre in this research. EVI well documented the annual seasonal growth of vegetation and clearly distinguished the characteristic phenology of four different land use types; native forest, plantation, agriculture and mixed wooded/cleared area. Native forests maintained high EVI throughout the year, while plantations, wooded/cleared areas and agriculture showed greater inter-annual variation, with minimum EVI at the end of the dry season in April and maximum EVI in September-October, around two months after the wet season peak in rainfall. The BFAST analysis detected abrupt temporal changes in vegetation in the tropical forests, especially in a large conversion of mixed wooded/cleared area into plantation. Within the study area from 2001-2012 there has been an overall decreasing trend of vegetation cover for

Changes in the properties of superalloys by long term heating

International Nuclear Information System (INIS)

Susukida, H.; Tsuji, I.; Kawai, H.

1976-01-01

A laboratory study was conducted in order to determine the effect of long term heating (max. 10000h at 850 0 and 950 0 C) on the microstructure, tensile properties, hardness and stress rupture properties of four kinds of superalloys. These superalloys are two kinds of solid solution hardened Ni-base superalloys Hastelloy X and Inconel 617 and two kinds of dispersion strengthened Ni-base superalloys TD-Ni and TD-NiCr. The result of the study can be summarized as follows: (1) Solid solution hardened superalloys: Many precipitates were observed in the grains and on the grain boundaries after 100 hours of heating, and the precipitates became coarse-grained by over 1000 hours of heating. This tendency was remarkable when they were heated at 950 0 C. With the change of their microstructure, their mechanical properties also changed, particularly their tensile ductility decreased remarkably. (2) Dispersion strengthened superalloys: Their microstructure and mechanical properties were almost unchanged by long term heating. (3) The authors proposed ''solid solution hardening value'' in order to grasp quantitatively the solid solution hardening which has been discussed by the content of each element hitherto. (auth.)

Long-term climatic change and sustainable ground water resources management

International Nuclear Information System (INIS)

Loaiciga, Hugo A

2009-01-01

Atmospheric concentrations of greenhouse gases (GHGs), prominently carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), and halocarbons, have risen from fossil-fuel combustion, deforestation, agriculture, and industry. There is currently heated national and international debate about the consequences of such increasing concentrations of GHGs on the Earth's climate, and, ultimately, on life and society in the world as we know it. This paper reviews (i) long-term patterns of climate change, secular climatic variability, and predicted population growth and their relation to water resources management, and, specifically, to ground water resources management, (ii) means available for mitigating and adapting to trends of climatic change and climatic variability and their impacts on ground water resources. Long-term (that is, over hundreds of millions of years), global-scale, climatic fluctuations are compared with more recent (in the Holocene) patterns of the global and regional climates to shed light on the meaning of rising mean surface temperature over the last century or so, especially in regions whose historical hydroclimatic records exhibit large inter-annual variability. One example of regional ground water resources response to global warming and population growth is presented.

Incidence of climate on common frog breeding: Long-term and short-term changes

Science.gov (United States)

Neveu, André

2009-09-01

In Brittany (northwest France), the climate is showing a trend toward warming. This change is increasingly suspected to have a role in driving amphibian decline, but it is very difficult to determine at what level the climate affects the future of species. Recently, some studies have detected some direct effects on breeding phenology and indirect effects on energy allocation. The present study explores some of these effects on the common frog ( Rana temporaria) from 1984 to 2007. The results show two trends: a long-term change in breeding activities and a short-term influence due to the 2003 climatic anomaly. For the period of study, the start of egg-laying shows a precocity that was correlated with thermal conditions during the preceding 40 days as well as milder springs during the previous year. This degree of precocity is currently the highest found in Europe (+26.6 days). As a result of the 2003 heat wave, the clutch mean fecundity in 2004 was smaller than for other years, the fecundity rates were reduced and abortions were numerous (unlike other years). Moreover, young females were the smallest observed in recent years and some females seemed to exhibit a trade-off between fecundity and growth. Before or after egg-laying, female body condition and mean weight of mature ovules were both lower. The year 2005 appears as a transition period before the recovery in 2006-2007. The results show that climate warming endangers the vital rates of the common frog, while the 2003 climatic events seem more detrimental than the long-term warming trend.

Short-term vegetation change on rehabilitated peatland on Rietvlei Nature Reserve

Directory of Open Access Journals (Sweden)

C.E. Venter

2003-12-01

Full Text Available Natural peatlands occur on the Rietvlei Nature Reserve. Before the Pretoria City Council acquired the land, these peatlands were mined by private land-owners. Ditches were constructed to drain the area for mining and the peatlands became desicrated. Later the area was proclaimed as a nature reserve and has since then been managed as such. Rehabilitation of the drained peatland on Rietvlei Nature Reserve first started in 2000 as a Working for Water project. The aim of the rehabilitation was to close the ditches and rewet the peatland, to enable possible revival of the peatland. A baseline vegetation survey was undertaken during the summer (March to April of 2001 to determine the nature of the pioneer communities that established on the rehabilitated area. This survey was repeated during the summer (March to April of 2002 to detect changes in the vegetation. The same sample plots were used on both occasions. The initial pioneer vegetation was mostly composed of weedy annuals.

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...

What factors influence the effectiveness of financial incentives on long-term natural resource management practice change?

Directory of Open Access Journals (Sweden)

Emma Swann

2016-12-01

Full Text Available Financial incentives are used by natural resource management organisations to encourage landholders to adopt sustainable practices where the outcomes on a farm scale may be negative or marginal. There is a growing body of research aimed at understanding why landholders do or do not agree to participate in financial incentive programs, however research that considers when and how financial incentives work to bring about long-term behaviour change is relatively immature. The purpose of this review is to answer the question ‘What factors influence the effectiveness of financial incentives on long-term natural resource management practice change?’ In synthesising the evidence, it was found that there are numerous characteristics of the practice change itself, along with the program design and implementation, which are important to understand long-term behaviour change. These include whether inexpensive maintenance or long-term funding is available; whether the changes are relatively simple to sustain; whether the program involves structural changes; whether there is land use rigidity; and whether the changes have resulting environmental benefits that are highly observable. Additionally, it is advisable for programs that use financial incentives to include the following program features: ongoing extension support and a focus on building relationship and trust; flexibility in how the practice change is applied; active landholder involvement from planning to evaluation; and contract length that is appropriate for the complexity of the NRM practice. These characteristics can be used to guide policy makers in their natural resource management investment decisions. There is a clear need for greatly increased monitoring and evaluation of existing programs, both during the program and after its conclusion, in order to more fully understand its long-term impacts and ultimate effectiveness. Finally, landholders undertaking a practice change generally

Resurveying historical vegetation data – opportunities and challenges

Czech Academy of Sciences Publication Activity Database

Kapfer, J.; Hédl, Radim; Jurasinski, G.; Kopecký, Martin; Schei, F. H.; Grytnes, J.-A.

2017-01-01

Roč. 20, č. 2 (2017), s. 164-171 ISSN 1402-2001 EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : environmental change * long-term vegetation dynamics * vegetation resampling Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 2.474, year: 2016

Long-term WWER-440 dynamics in cyclic power output changes

International Nuclear Information System (INIS)

Petruzela, I.

1989-01-01

Xenon poisoning is one of the main factors limiting the operation of a nuclear power plant with a WWER-440 reactor in the variable load mode, when long-term dynamics applies to cyclic power output changes. An analysis of the xenon poisoning linearized transfer shows that a phase shift of 180deg takes place between the summed-up reactivity change due to a power change and the reactivity change due to xenon poisoning, this for a sine-wave power change with a period of 24 hours. Thus, the requirements are minimized for the change in reactivity of the control elements, and the maximum value can be achieved of released reactivity that can be utilized before the end of the campaign. (B.S.). 6 figs., 4 tabs., 9 refs

Surviving in Changing Seascapes: Sediment Dynamics as Bottleneck for Long-Term Seagrass Presence

NARCIS (Netherlands)

Suykerbuyk, W.; Bouma, T.J.; Govers, L.L.; Giesen, K.; de Jong, D.J.; Herman, P.M.J.; Hendriks, J.; van Katwijk, M.M.

2016-01-01

Changes in the seascape often result in altered hydrodynamics that lead to coinciding changes in sediment dynamics. Little is known on how altered sediment dynamics affect long-term seagrass persistence. We studied the thresholds of sediment dynamics in relation to seagrass presence by comparing

Research priorities for grassland science: the need of long term integrated experiments networks

Directory of Open Access Journals (Sweden)

G. Lemaire

2007-07-01

Full Text Available Grasslands have to be considered not only as a mean for providing foods for domestic herbivore but also as an important biome of terrestrial biosphere. This function of grasslands as an active component of our environment requires specific studies on the role and impact of this ecosystem on soil erosion and soil quality, quality and quantity of water resources, atmosphere composition and greenhouse gas emission or sequestration, biodiversity dynamics at different scales from field plot to landscape. All these functions have to be evaluated in conjunction with the function of providing animal products for increasing human population. So multifunctionality of grasslands become a new paradigm for grassland science. Environmental and biodiversity outputs require long term studies, being the long term retro-active processes within soil, vegetation and micro-organism communities in relation to changes in management programme. So grassland science needs to carry on long term integrated experimentation for studying all the environmental outputs and ecological services associated to grassland management systems.

Flood effects on an Alaskan stream restoration project: the value of long-term monitoring

Science.gov (United States)

Densmore, Roseann V.; Karle, Kenneth F.

2009-01-01

On a nationwide basis, few stream restoration projects have long-term programs in place to monitor the effects of floods on channel and floodplain configuration and floodplain vegetation, but long-term and event-based monitoring is required to measure the effects of these stochastic events and to use the knowledge for adaptive management and the design of future projects. This paper describes a long-term monitoring effort (15 years) on a stream restoration project in Glen Creek in Denali National Park and Preserve in Alaska. The stream channel and floodplain of Glen Creek had been severely degraded over a period of 80 years by placer mining for gold, which left many reaches with unstable and incised streambeds without functioning vegetated floodplains. The objectives of the original project, initiated in 1991, were to develop and test methods for the hydraulic design of channel and floodplain morphology and for floodplain stabilization and riparian habitat recovery, and to conduct research and monitoring to provide information for future projects in similar degraded watersheds. Monitoring methods included surveyed stream cross-sections, vegetation plots, and aerial, ground, and satellite photos. In this paper we address the immediate and outlying effects of a 25-year flood on the stream and floodplain geometry and riparian vegetation. The long-term monitoring revealed that significant channel widening occurred following the flood, likely caused by excessive upstream sediment loading and the fairly slow development of floodplain vegetation in this climate. Our results illustrated design flaws, particularly in regard to identification and analysis of sediment sources and the dominant processes of channel adjustment.

Ten years of vegetation assembly after a North American mega-fire

Science.gov (United States)

Scott Abella; Paula J. Fornwalt

2015-01-01

Altered fuels and climate change are transforming fire regimes in many of Earth's biomes. Postfire reassembly of vegetation - paramount to C storage and biodiversity conservation ­ frequently remains unpredictable and complicated by rapid global change. Using a unique data set of pre and long-term postfire data, combined with long-term data from nearby unburned...

Emulation of long-term changes in global climate: Application to the late Pliocene and future

KAUST Repository

Lord, Natalie S.

2017-04-26

Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs), long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term

Emulation of long-term changes in global climate: application to the late Pliocene and future

KAUST Repository

Lord, Natalie S.

2017-11-16

Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs), long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term

Emulation of long-term changes in global climate: application to the late Pliocene and future

KAUST Repository

Lord, Natalie S.; Crucifix, Michel; Lunt, Dan J.; Thorne, Mike C.; Bounceur, Nabila; Dowsett, Harry; O& apos; Brien, Charlotte L.; Ridgwell, Andy

2017-01-01

Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs), long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term

Emulation of long-term changes in global climate: Application to the late Pliocene and future

KAUST Repository

Lord, Natalie S.; Crucifix, Michel; Lunt, Dan J.; Thorne, Mike C.; Bounceur, Nabila; Dowsett, Harry; O& apos; Brien, Charlotte L.; Ridgwell, Andy

2017-01-01

Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs), long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term

The effect of long-term changes in plant inputs on soil carbon stocks

Science.gov (United States)

Georgiou, K.; Li, Z.; Torn, M. S.

2017-12-01

Soil organic carbon (SOC) is the largest actively-cycling terrestrial reservoir of C and an integral component of thriving natural and managed ecosystems. C input interventions (e.g., litter removal or organic amendments) are common in managed landscapes and present an important decision for maintaining healthy soils in sustainable agriculture and forestry. Furthermore, climate and land-cover change can also affect the amount of plant C inputs that enter the soil through changes in plant productivity, allocation, and rooting depth. Yet, the processes that dictate the response of SOC to such changes in C inputs are poorly understood and inadequately represented in predictive models. Long-term litter manipulations are an invaluable resource for exploring key controls of SOC storage and validating model representations. Here we explore the response of SOC to long-term changes in plant C inputs across a range of biomes and soil types. We synthesize and analyze data from long-term litter manipulation field experiments, and focus our meta-analysis on changes to total SOC stocks, microbial biomass carbon, and mineral-associated (`protected') carbon pools and explore the relative contribution of above- versus below-ground C inputs. Our cross-site data comparison reveals that divergent SOC responses are observed between forest sites, particularly for treatments that increase C inputs to the soil. We explore trends among key variables (e.g., microbial biomass to SOC ratios) that inform soil C model representations. The assembled dataset is an important benchmark for evaluating process-based hypotheses and validating divergent model formulations.

Long-term vegetation changes in a temperate forest impacted by climate change

Science.gov (United States)

Lauren E. Oakes; Paul E. Hennon; Kevin L. O' Hara; Rodolfo Dirzo

2014-01-01

Pervasive forest mortality is expected to increase in future decades as a result of increasing temperatures. Climate-induced forest dieback can have consequences on ecosystem services, potentially mediated by changes in forest structure and understory community composition that emerge in response to tree death. Although many dieback events around the world have been...

Perceived stress and anhedonia predict short-and long-term weight change, respectively, in healthy adults.

Science.gov (United States)

Ibrahim, Mostafa; Thearle, Marie S; Krakoff, Jonathan; Gluck, Marci E

2016-04-01

Perceived stress; emotional eating; anhedonia; depression and dietary restraint, hunger, and disinhibition have been studied as risk factors for obesity. However, the majority of studies have been cross-sectional and the directionality of these relationships remains unclear. In this longitudinal study, we assess their impact on future weight change. Psychological predictors of weight change in short- (6month) and long-term (>1year) periods were studied in 65 lean and obese individuals in two cohorts. Subjects participated in studies of food intake and metabolism that did not include any type of medication or weight loss interventions. They completed psychological questionnaires at baseline and weight change was monitored at follow-up visits. At six months, perceived stress predicted weight gain (r(2)=0.23, P=0.02). There was a significant interaction (r(2)=.38, P=0.009) between perceived stress and positive emotional eating, such that higher scores in both predicted greater weight gain, while those with low stress but high emotional eating scores lost weight. For long-term, higher anhedonia scores predicted weight gain (r(2)=0.24, P=0.04). Depression moderated these effects such that higher scores in both predicted weight gain but higher depression and lower anhedonia scores predicted weight loss. There are different behavioral determinants for short- and long-term weight change. Targeting perceived stress may help with short-term weight loss while depression and anhedonia may be better targets for long-term weight regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vegetation change, malnutrition and violence in the Horn of Africa

Science.gov (United States)

Rowhani, P.; Degomme, O.; Linderman, M.; Guha-Sapir, D.; Lambin, E.

2008-12-01

In certain circumstances, climate change in association with a broad range of social factors may increase the risk of famines and subsequently, violent conflict. The impacts of climate change on society will be experienced both through changes in mean conditions over long time periods and through increases in extreme events. Recent studies have shown the historical effects of long term climate change on societies and the importance of short term climatic triggers on armed conflict. However, most of these studies are at the state level ignoring local conditions. Here we use detailed information extracted from wide-swath satellite data (MODIS) to analyze the impact of climate variability change on malnutrition and violent conflict. More specifically, we perform multivariate logistic regression analysis in order to explain the geographical distribution of malnutrition and conflict in the Horn of Africa on a sub-national level. This region, constituted by several unstable and poor states, has been affected by droughts, floods, famines, and violence in the past few years. Three commonly used nutrition and mortality indicators are used to characterize the health situation (CE-DAT database). To map violence we use the georeferenced Armed Conflicts dataset developed by the Center for the Study of Civil War. Explanatory variables include several socio-economic variables and environmental variables characterizing land degradation, vegetation activity, and interannual variability in land-surface conditions. First results show that interannual variability in land-surface conditions is associated with malnutrition but not with armed conflict. Furthermore, land degradation seems not to be associated with either malnutrition or armed conflict.

Vegetation cover, tidal amplitude and land area predict short-term marsh vulnerability in Coastal Louisiana

Science.gov (United States)

Schoolmaster, Donald; Stagg, Camille L.; Sharp, Leigh Anne; McGinnis, Tommy S.; Wood, Bernard; Piazza, Sarai

2018-01-01

The loss of coastal marshes is a topic of great concern, because these habitats provide tangible ecosystem services and are at risk from sea-level rise and human activities. In recent years, significant effort has gone into understanding and modeling the relationships between the biological and physical factors that contribute to marsh stability. Simulation-based process models suggest that marsh stability is the product of a complex feedback between sediment supply, flooding regime and vegetation response, resulting in elevation gains sufficient to match the combination of relative sea-level rise and losses from erosion. However, there have been few direct, empirical tests of these models, because long-term datasets that have captured sufficient numbers of marsh loss events in the context of a rigorous monitoring program are rare. We use a multi-year data set collected by the Coastwide Reference Monitoring System (CRMS) that includes transitions of monitored vegetation plots to open water to build and test a predictive model of near-term marsh vulnerability. We found that despite the conclusions of previous process models, elevation change had no ability to predict the transition of vegetated marsh to open water. However, we found that the processes that drive elevation change were significant predictors of transitions. Specifically, vegetation cover in prior year, land area in the surrounding 1 km2 (an estimate of marsh fragmentation), and the interaction of tidal amplitude and position in tidal frame were all significant factors predicting marsh loss. This suggests that 1) elevation change is likely better a predictor of marsh loss at time scales longer than we consider in this study and 2) the significant predictive factors affect marsh vulnerability through pathways other than elevation change, such as resistance to erosion. In addition, we found that, while sensitivity of marsh vulnerability to the predictive factors varied spatially across coastal Louisiana

Changes in heart rate variability are associated with expression of short-term and long-term contextual and cued fear memories.

Directory of Open Access Journals (Sweden)

Jun Liu

Full Text Available Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I and a more variable phase (stage-II. We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice.

Long term monitoring system integrated in an elevational gradient in NW Argentina

Science.gov (United States)

Carilla, J.; Malizia, A.; Osinaga, O.; Blundo, C.; Grau, R.; Malizia, L.; Aráoz, E.

2013-05-01

composition over time, despite different previous land use. Floristic changes are also reflected in structural changes, showing an increasing trend in biomass in the last 15 years for most of the plots. Exotic tree species are expanding their distribution (e.g. Ligustrum lucidum) and have a strong influence on the structure and dynamics of some secondary forests. 2) High Andean vegetation diversity decrease with altitude, while several functional groups cover increase with temperature. 3) There is a clear association between lake fluctuations, ecosystem productivity and regional climatic patterns. The long term record provided by dendrochronology showed that plant productivity of the last decades is the lowest in the last 180 years, with a consistent drying trend in the last years. We are generating longer temporal series of meteorological data and biological ecosystems measurements; this will help to differentiate between the effect of climate change, land use change and natural ecosystems variability, to understand the way vegetation and ecosystems response to these changes.

Adaptive Change Detection for Long-Term Machinery Monitoring Using Incremental Sliding-Window

Science.gov (United States)

Wang, Teng; Lu, Guo-Liang; Liu, Jie; Yan, Peng

2017-11-01

Detection of structural changes from an operational process is a major goal in machine condition monitoring. Existing methods for this purpose are mainly based on retrospective analysis, resulting in a large detection delay that limits their usages in real applications. This paper presents a new adaptive real-time change detection algorithm, an extension of the recent research by combining with an incremental sliding-window strategy, to handle the multi-change detection in long-term monitoring of machine operations. In particular, in the framework, Hilbert space embedding of distribution is used to map the original data into the Re-producing Kernel Hilbert Space (RKHS) for change detection; then, a new adaptive threshold strategy can be developed when making change decision, in which a global factor (used to control the coarse-to-fine level of detection) is introduced to replace the fixed value of threshold. Through experiments on a range of real testing data which was collected from an experimental rotating machinery system, the excellent detection performances of the algorithm for engineering applications were demonstrated. Compared with state-of-the-art methods, the proposed algorithm can be more suitable for long-term machinery condition monitoring without any manual re-calibration, thus is promising in modern industries.

Long-Term Developmental Changes in Children's Lower-Order Big Five Personality Facets

NARCIS (Netherlands)

A.D. de Haan (Amaranta); S.S.W. de Pauw (Sarah); A.L. van den Akker (Alithe); M. Deković (Maja); P.J. Prinzie (Peter)

2016-01-01

markdownabstract__Objective:__ This study examined long-term developmental changes in mother-rated lower-order facets of children's Big Five dimensions. __Method:__ Two independent community samples covering early childhood (2-4.5 years; N=365, 39% girls) and middle childhood to the end of middle

Biochemical Changes in Erythrocytes as a Molecular Marker of Cell Damage during Long-Term Simvastatin Treatment.

Science.gov (United States)

Mikashinovich, Z I; Belousova, E S

2016-08-01

Long-term administration of simvastatin to rats, irrespective of the baseline cholesterol levels, induced biochemical changes in erythrocytes attesting to hypoxic damage (accumulation of lactate and 2,3-diphosphoglycerate), disturbances in ATP-dependent mechanisms of ion homeostasis regulation (decrease in total ATPase and Ca(2+)-ATPase activities), and antioxidant enzymes system imbalance. These changes can be considered as a sensitive indicator and molecular basis of cell damage during long-term administration of statins.

Nonlinear vegetation cover changes in the North Ethiopian Highlands: Evidence from the Lake Ashenge closed basin

Energy Technology Data Exchange (ETDEWEB)

Lanckriet, Sil, E-mail: sil.lanckriet@ugent.be [Department of Geography, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent (Belgium); Rucina, Stephen [National Museum of Kenya, Earth Science Department, Palynology Section, P.O. Box 40658 00100, Nairobi (Kenya); Frankl, Amaury [Department of Geography, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent (Belgium); Ritler, Alfons [Centre for Development and Environment, University of Bern, Hallerstrasse 10, CH-3012 Bern (Switzerland); Gelorini, Vanessa [Department of Geology and Soil Science, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent (Belgium); Nyssen, Jan [Department of Geography, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent (Belgium)

2015-12-01

Vegetation cover changes in African drylands are often thought to result from population growth, social factors and aridification. Here we show that long-term vegetation proxy records can help disentangling these main driving factors. Taking the case of North Ethiopia, we performed an integrated investigation of land cover changes over the last four centuries around the endorheic Lake Ashenge, as derived from pollen analysis and repeat photography complemented with information from historical sources. Pollen and sediment analysis of radiocarbon-dated lake deposits shows a phase of environmental destabilization during the 18th century, after a more stable previous period. This is evidenced by decreases of tree pollen (Juniperus, Olea, Celtis, Podocarpus < 5%), increases in Poaceae (> 40%) and deposition of coarser silt lake sediments (> 70%). Quantitative analysis of 30 repeated landscape photographs around the lake indicates a gradual decline of the vegetation cover since a relative maximum during the mid-19th Century. Vegetation cover declined sharply between the 1950s and the 1980s, but has since begun to recover. Overall, the data from around Lake Ashenge reveal a nonlinear pattern of deforestation and forest regrowth with several periods of vegetation cover change over the past four centuries. While there is forcing of regional drought and the regional land tenure system, the cyclic changes do not support a simplified focus on aridification or population growth. - Highlights: • Vegetation cover changes are often related with population growth or climate • We investigated land cover changes over the last four centuries near Lake Ashenge • Overall, the data reveal a nonlinear pattern of deforestation and forest regrowth.

Nonlinear vegetation cover changes in the North Ethiopian Highlands: Evidence from the Lake Ashenge closed basin

International Nuclear Information System (INIS)

Lanckriet, Sil; Rucina, Stephen; Frankl, Amaury; Ritler, Alfons; Gelorini, Vanessa; Nyssen, Jan

2015-01-01

Vegetation cover changes in African drylands are often thought to result from population growth, social factors and aridification. Here we show that long-term vegetation proxy records can help disentangling these main driving factors. Taking the case of North Ethiopia, we performed an integrated investigation of land cover changes over the last four centuries around the endorheic Lake Ashenge, as derived from pollen analysis and repeat photography complemented with information from historical sources. Pollen and sediment analysis of radiocarbon-dated lake deposits shows a phase of environmental destabilization during the 18th century, after a more stable previous period. This is evidenced by decreases of tree pollen (Juniperus, Olea, Celtis, Podocarpus < 5%), increases in Poaceae (> 40%) and deposition of coarser silt lake sediments (> 70%). Quantitative analysis of 30 repeated landscape photographs around the lake indicates a gradual decline of the vegetation cover since a relative maximum during the mid-19th Century. Vegetation cover declined sharply between the 1950s and the 1980s, but has since begun to recover. Overall, the data from around Lake Ashenge reveal a nonlinear pattern of deforestation and forest regrowth with several periods of vegetation cover change over the past four centuries. While there is forcing of regional drought and the regional land tenure system, the cyclic changes do not support a simplified focus on aridification or population growth. - Highlights: • Vegetation cover changes are often related with population growth or climate • We investigated land cover changes over the last four centuries near Lake Ashenge • Overall, the data reveal a nonlinear pattern of deforestation and forest regrowth

Exploring vegetation in the fourth dimension.

Science.gov (United States)

Mitchell, Fraser J G

2011-01-01

Much ecological research focuses on changes in vegetation on spatial scales from stands to landscapes; however, capturing data on vegetation change over relevant timescales remains a challenge. Pollen analysis offers unrivalled access to data with global coverage over long timescales. Robust techniques have now been developed that enable pollen data to be converted into vegetation data in terms of individual taxa, plant communities or biomes, with the possibility of deriving from those data a range of plant attributes and ecological indicators. In this review, I discuss how coupling pollen with macrofossil, charcoal and genetic data opens up the extensive pollen databases to investigation of the drivers of vegetation change over time and also provides extensive data sets for testing hypotheses with wide ecological relevance. © 2010 Elsevier Ltd. All rights reserved.

Lock-in and change: Distributed generation in Denmark in a long-term perspective

International Nuclear Information System (INIS)

Vleuten, Erik van der; Raven, Rob

2006-01-01

There is a renewed attention for distributed generation (DG) in European electricity sectors, but implementing DG is often problematic. This article studies the current relative success of DG in Denmark. We take into account not only recent drivers of change such as energy policy and green activism, but also long-term stability and change in the electricity supply sector. In particular we analyse the lock-in on centralized electricity supply, that still frustrates DG development elsewhere. We discuss three successive national electricity regimes, analysing regime lock-in and change in terms of technologies, actors, institutions and the position of DG. Our analysis shows that Danish energy policy as well as innovative activity by key actors indeed were crucial to the recent DG revival in Denmark. On the other hand, our long-term perspective shows that Danish energy policy and actor strategies were tuned to specifically Danish opportunities and barriers created during earlier regimes. These include experience with wind turbines and CHP as well as urban municipal and rural cooperative involvement. Copying the Danish energy policy model to other countries, regardless of national specific opportunities and barriers, will therefore not guarantee a similar outcome

Long-term developmental changes in children's lower-order Big Five personality facets

NARCIS (Netherlands)

Haan, A.D. de; Pauw, S. de; Akker, A.J. van den; Dekovic, M.; Prinzie, P.

2017-01-01

Objective: This study examined long-term developmental changes in mother-rated lower-order facets of children's Big Five dimensions. Method: Two independent community samples covering early childhood (2-4.5 years; N = 365, 39% girls) and middle childhood to the end of middle adolescence (6-17 years;

Regeneration after fire in campo rupestre : Short- and long-term vegetation dynamics

OpenAIRE

Le Stradic , Soizig; Hernandez , Pauline; Fernandes , Geraldo Wilson; Buisson , Elise

2018-01-01

International audience; The Cerrado (Brazilian savanna) is the second largest biome in Brazil, covering 22% of the country, and campo rupestre is one of the most biodiverse ecosystem. Campo rupestre are extremely old mountaintop tropical ecosystems, composed of a mosaic of herbaceous, shrubland and savanna vegetation, generally located above 900 m above sea level characterized by shallow, acidic and nutrient-poor soils. In the context of increased land-use changes, effective conservation and ...

Intraindividual Variability and Long-Term Changes of Thermal Quantitative Sensory Testing

DEFF Research Database (Denmark)

Krøigård, Thomas; Sothynathan, Isaivani; Sindrup, Søren H

2015-01-01

Thermal threshold examinations are widely used in the clinical setting and in studies to assess the function of the peripheral sensory nervous system. Little is known about the variation from one side of the body to the other and the long-term temporal changes and variability. In this study, 134...... and foot. Bilateral stimulations resulted in relative intertrial variations ranging from 19% to 40%. There was no significant temporal change for repeated measures. Analysis of the individual measurements of each subject at baseline and at 26 weeks, however, resulted in relatively large intertrial...

Facilitating long-term changes in student approaches to learning science.

Science.gov (United States)

Buchwitz, Brian J; Beyer, Catharine H; Peterson, Jon E; Pitre, Emile; Lalic, Nevena; Sampson, Paul D; Wakimoto, Barbara T

2012-01-01

Undergraduates entering science curricula differ greatly in individual starting points and learning needs. The fast pace, high enrollment, and high stakes of introductory science courses, however, limit students' opportunities to self-assess and modify learning strategies. The University of Washington's Biology Fellows Program (BFP) intervenes through a 20-session, premajors course that introduces students to the rigor expected of bioscience majors and assists their development as science learners. This study uses quantitative and qualitative approaches to assess whether the 2007-2009 BFP achieved its desired short- and long-term impacts on student learning. Adjusting for differences in students' high school grade point average and Scholastic Aptitude Test scores, we found that participation in the BFP was associated with higher grades in two subsequent gateway biology courses, across multiple quarters and instructors. Two to 4 yr after participating in the program, students attributed changes in how they approached learning science to BFP participation. They reported having learned to "think like a scientist" and to value active-learning strategies and learning communities. In addition, they reported having developed a sense of belonging in bioscience communities. The achievement of long-term impacts for a short-term instructional investment suggests a practical means to prepare diverse students for the rigors of science curricula.

Long-term hydrologic effects on marsh plant community structure in the southern Everglades

Science.gov (United States)

Busch, David E.; Loftus, W.F.; Bass, O.L.

1998-01-01

Although large-scale transformation of Everglades landscapes has occurred during the past century, the patterns of association among hydrologic factors and southern Everglades freshwater marsh vegetation have not been well-defined. We used a 10-year data base on the aquatic biota of Shark Slough to classify vegetation and describe plant community change in intermediate- to long-hydroperiod Everglades marshes. Study area marsh vegetation was quantitatively grouped into associations dominated by 1) Cladium jamaicense, 2) a group of emergents including Eleocharis cellulosa, Sagittaria lancifolia, and Rhyncospora tracyi, 3) taxa associated with algal mats (Utricularia spp. and Bacopa caroliniana), and 4) the grasses Panicum hemitomon and Paspalidium geminatum. During the decade evaluated, the range of water depths that characterized our study sites approached both extremes depicted in the 40-year hydrologic record for the region. Water depths were near the long-term average during the mid-1980s, declined sharply during a late 1980s drought, and underwent a prolonged increase from 1991 through 1995. Overall macrophyte cover varied inversely with water depth, while the response of periphyton was more complex. An ordination analysis, based on plant species abundance, revealed that study area vegetation structure was associated with hydrologic patterns. Marsh plant community structure showed evidence of cyclic interannual variation corresponding to hydrologic change over the decade evaluated. Lower water depths, the occurrence of marl substrates, and high periphyton cover were correlated. These factors contributed to reduced macrophyte cover in portions of the study area from which water had been diverted.

Application of a Coupled Vegetation Competition and Groundwater Simulation Model to Study Effects of Sea Level Rise and Storm Surges on Coastal Vegetation

Directory of Open Access Journals (Sweden)

Su Yean Teh

2015-09-01

Full Text Available Global climate change poses challenges to areas such as low-lying coastal zones, where sea level rise (SLR and storm-surge overwash events can have long-term effects on vegetation and on soil and groundwater salinities, posing risks of habitat loss critical to native species. An early warning system is urgently needed to predict and prepare for the consequences of these climate-related impacts on both the short-term dynamics of salinity in the soil and groundwater and the long-term effects on vegetation. For this purpose, the U.S. Geological Survey’s spatially explicit model of vegetation community dynamics along coastal salinity gradients (MANHAM is integrated into the USGS groundwater model (SUTRA to create a coupled hydrology–salinity–vegetation model, MANTRA. In MANTRA, the uptake of water by plants is modeled as a fluid mass sink term. Groundwater salinity, water saturation and vegetation biomass determine the water available for plant transpiration. Formulations and assumptions used in the coupled model are presented. MANTRA is calibrated with salinity data and vegetation pattern for a coastal area of Florida Everglades vulnerable to storm surges. A possible regime shift at that site is investigated by simulating the vegetation responses to climate variability and disturbances, including SLR and storm surges based on empirical information.

A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA

Science.gov (United States)

Scott A. Mensing; John L. Korfmacher; Thomas Minckley; Robert C. Musselman

2012-01-01

Future climate projections predict warming at high elevations that will impact treeline species, but complex topographic relief in mountains complicates ecologic response, and we have a limited number of long-term studies examining vegetation change related to climate. In this study, pollen and conifer stomata were analyzed from a 2.3 m sediment core extending to 15,...

Sustainable Change Sequence: a framework for developing behavior change interventions for patients with long-term conditions

OpenAIRE

Elwyn, Glyn; Marrin, Katy; Frosch, Dominick; White, James

2014-01-01

Objective\\ud \\ud Interactive interventions are increasingly advocated to support behavior change for patients who have long-term conditions. Such interventions are most likely to achieve behavior change when they are based on appropriate theoretical frameworks. Developers of interventions are faced with a diverse set of behavioral theories that do not specifically address intervention development. The aim of our work was to develop a framework to guide the developers of interactive healthcare...

Vegetation response to climate change : implications for Canada's conservation lands

International Nuclear Information System (INIS)

Scott, D.; Lemieux, C.

2003-01-01

Studies have shown that Canada's national parks are vulnerable to the impacts of climate change. A wide range of biophysical climate change impacts could affect the integrity of conservation lands in each region of Canada. This report examines the potential impact of climate change on landscape alterations and vegetation distribution in Canada's wide network of conservation lands. It also presents several ways to integrate climate change into existing conservation policy and adaptation strategies. Canada's conservation lands include provincial parks, migratory bird sanctuaries, national wildlife areas and wildlife protected areas. This is the first study to examine biome changes by applying an equilibrium Global Vegetation Model (GVM) to Canada's network of national park systems. Some of the policy and planning challenges posed by changes in landscape level vegetation were also addressed. The report indicates that in terms of potential changes to the biome classification of Canada's national forests, more northern biomes are projected to decrease. These northern biomes include the tundra, taiga and boreal conifer forests. 56 refs., 8 tabs., 6 figs

Development of a Long-term Sampling Network to Monitor Restoration Success in the Southwest Coastal Everglades: Vegetation, Hydrology, and Sediments

Science.gov (United States)

Smith, Thomas J.

2004-01-01

Introduction and History Hurricane Andrew, a Category 5 storm, crossed the southern Florida peninsula on the morning of August 24, 1992 (Fig. 1). Following the storm, the National Park Service conducted an environmental damage assessment to gauge the storm's impacts on the natural resources of south Florida Park Service holdings (Pimm et al., 1994). Although hurricanes have impacted Park Service lands such as the Everglades in the past (Houston and Powell, 2003), no systematic, permanent sampling scheme has been established to monitor long-term recovery (or lack thereof) following disturbance. In October 1992, vegetation monitoring plots were established in heavily damaged areas of mangrove forest on the southwest coast of the Everlgades, along the Lostmans and Broad Rivers (Smith et al., 1994, see Fig. 2). As the permanent plot network was being established, funding was awarded for the South Florida Global Climate Change project (SOFL-GCC). This led to the establishment of a network of hydrological monitoring stations (Anderson and Smith, 2004). Finally, sediment elevation tables (SETs) were installed at many locations. SETs provide the means to measure very small changes (2 mm) in the sediment surface elevation accurately over time (Cahoon et al., 2002). We also set up marker horizons to measure accretion of sediment at each site (Smith and Cahoon, 2003). Sampling sites were located along three transects extending from upstream freshwater wetlands to downstream saltwater wetlands along the Shark, Lostmans and Chatham Rivers in Everglades National Park (Fig. 2). While we were developing our sampling network for basic scientific research needs, concern mounted over the health of the Greater Everglades Ecosystem and in particular over the influence of decreased freshwater flows (Smith et al., 1989). Ecosystem restoration planning was begun, resulting in the multi-agency, $8 billion Comprehensive Everglades Restoration Plan (CERP). Our co-located sampling networks

Evidence from a rare case-study for Hebbian-like changes in structural connectivity induced by long-term deep brain stimulation

Directory of Open Access Journals (Sweden)

Tim J Van Hartevelt

2015-06-01

Full Text Available It is unclear whether Hebbian-like learning occurs at the level of long-range white matter connections in humans, i.e. where measurable changes in structural connectivity are correlated with changes in functional connectivity. However, the behavioral changes observed after deep brain stimulation (DBS suggest the existence of such Hebbian-like mechanisms occurring at the structural level with functional consequences. In this rare case study, we obtained the full network of white matter connections of one patient with Parkinson's disease before and after long-term DBS and combined it with a computational model of ongoing activity to investigate the effects of DBS-induced long-term structural changes. The results show that the long-term effects of DBS on resting-state functional connectivity is best obtained in the computational model by changing the structural weights from the subthalamic nucleus to the putamen and the thalamus in a Hebbian-like manner. Moreover, long-term DBS also significantly changed the structural connectivity towards normality in terms of model-based measures of segregation and integration of information processing, two key concepts of brain organization. This novel approach using computational models to model the effects of Hebbian-like changes in structural connectivity allowed us to causally identify the possible underlying neural mechanisms of long-term DBS using rare case study data. In time, this could help predict the efficacy of individual DBS targeting and identify novel DBS targets.

Long-term climate change effects on dynamics of microorganisms and carbon in the root-zone

DEFF Research Database (Denmark)

Reinsch, Sabine

Climate change factors such as elevated CO2 concentration, warming and changes in precipitation patterns have been shown to affect terrestrial carbon (C) cycling. The objective of this Ph.D. project is to track recently assimilated C into belowground compartments to investigate the effects...... of climate change on belowground C allocation. The impacts of climate change as single and combined treatments were applied to heath/grassland vegetation and the short-term terrestrial C turnover was investigated using in-situ 13CO2 pulse-labeling. We developed a mobile and low-cost pulse-labeling setup...... have major impacts on the C balance under changing climatic conditions. A comparison of C allocation under ambient and simulated future climatic conditions showed that the terrestrial C balance might be changed by reducing soil organic matter mineralization. Our results suggest that the impact...

Effect of organisational change type and frequency on long-term sickness absence in hospitals.

Science.gov (United States)

Bernstrøm, Vilde H; Kjekshus, Lars Erik

2015-09-01

The present study was conducted to investigate how the frequency of structural change and patient care-related change is related to employees' long-term sickness absence. Although a growing body of research is investigating the potentially harmful effects of organisational change on employee health, most studies have focused on single episodes of organisational change and do not differentiate among the types and frequencies of change. National registry data were collected from 2005 and 2007. A total of 34 712 health professionals from 56 hospitals were included (76% nurses, 18% physicians and 6% other health professionals) and the data were analysed using multilevel logistic regression. The research findings reveal a significantly higher probability of long-term sickness absence among employees who experienced more frequent structural changes (OR = 1.03; CI: 1.00-1.06; P changes. A higher frequency of organisational change may lead to more sickness-related absence among employees, with the effect depending on the type of change. These findings highlight the need for managers who are contemplating or are in the process of implementing organisational change to become more aware of the potentially harmful effects of frequent organisational change on employee health. © 2014 John Wiley & Sons Ltd.

Heterogeneity in global vegetation and terrestrial climate change during the late Eocene to early Oligocene transition.

Science.gov (United States)

Pound, Matthew J; Salzmann, Ulrich

2017-02-24

Rapid global cooling at the Eocene - Oligocene Transition (EOT), ~33.9-33.5 Ma, is widely considered to mark the onset of the modern icehouse world. A large and rapid drop in atmospheric pCO 2 has been proposed as the driving force behind extinctions in the marine realm and glaciation on Antarctica. However, the global terrestrial response to this cooling is uncertain. Here we present the first global vegetation and terrestrial temperature reconstructions for the EOT. Using an extensive palynological dataset, that has been statistically grouped into palaeo-biomes, we show a more transitional nature of terrestrial climate change by indicating a spatial and temporal heterogeneity of vegetation change at the EOT in both hemispheres. The reconstructed terrestrial temperatures show for many regions a cooling that started well before the EOT and continued into the Early Oligocene. We conclude that the heterogeneous pattern of global vegetation change has been controlled by a combination of multiple forcings, such as tectonics, sea-level fall and long-term decline in greenhouse gas concentrations during the late Eocene to early Oligocene, and does not represent a single response to a rapid decline in atmospheric pCO 2 at the EOT.

Long-term changes in the flora and vegetation of Lake Mikołajskie (Poland as a result of its eutrophication

Directory of Open Access Journals (Sweden)

Barbara Solińska-Górnicka

2014-01-01

Full Text Available Changes in littoral flora as well as aquatic and swamp vegetation were analysed with increasing eutrophication of the mesotrophic Lake Mikołajskie. Over 30 years the habitat conditions of the lake deteriorated and the phy-tolittoral was reduced from a zone 6 metres wide to one of only 2 metres. In addition, the number of submerged macrophyte species decreased by 50% and the frequency of most of the remaining species declined severalfold. No new species were encountered. Species retreating from the lake littoral included all Chara species, Potamogeton obtusifolius, P. natans and Hydrocharis morsus-ranae. A significant lowering of the phytosociological diversity and species richness of aquatic and swamp communities was observed. By 1994, six of the 12 associations identified in 1964 and representing the submerged and floating-leaved vegetation (e.g. Nitellopsidetum ubtusae, Charetum asperae and Potamogetonetum compressi were no longer present. In turn, 6 swamp communities from among the original 14 identified in the lake were lacking (e.g. Typhetum angustifoliae, Sugittario-Sparganietum emersi and Eleocharitetum palustris. At the same time, two new aquatic and swamp communities appeared (Ranunculetum circinuti, Myriophylletum spicati, Caricetum acutiformis and Caricetum distichae. In contrast there was an increase in the species richness of reedswamp communities due to an influx of marshland species. While the 1990s witnessed a distinct decrease in concentrations of nutrients in Lake Mikołajskie, the consequent increase in water transparency was not associated with an increase in the area of submerged macrophytes, or the species richness of aquatic vegetation.

Long-term dataset on aquatic responses to concurrent climate change and recovery from acidification

Science.gov (United States)

Leach, Taylor H.; Winslow, Luke A.; Acker, Frank W.; Bloomfield, Jay A.; Boylen, Charles W.; Bukaveckas, Paul A.; Charles, Donald F.; Daniels, Robert A.; Driscoll, Charles T.; Eichler, Lawrence W.; Farrell, Jeremy L.; Funk, Clara S.; Goodrich, Christine A.; Michelena, Toby M.; Nierzwicki-Bauer, Sandra A.; Roy, Karen M.; Shaw, William H.; Sutherland, James W.; Swinton, Mark W.; Winkler, David A.; Rose, Kevin C.

2018-04-01

Concurrent regional and global environmental changes are affecting freshwater ecosystems. Decadal-scale data on lake ecosystems that can describe processes affected by these changes are important as multiple stressors often interact to alter the trajectory of key ecological phenomena in complex ways. Due to the practical challenges associated with long-term data collections, the majority of existing long-term data sets focus on only a small number of lakes or few response variables. Here we present physical, chemical, and biological data from 28 lakes in the Adirondack Mountains of northern New York State. These data span the period from 1994-2012 and harmonize multiple open and as-yet unpublished data sources. The dataset creation is reproducible and transparent; R code and all original files used to create the dataset are provided in an appendix. This dataset will be useful for examining ecological change in lakes undergoing multiple stressors.

Long-term contracts vs. short-term trade of natural gas - a European perspective

International Nuclear Information System (INIS)

Neuhoff, Karsten; Hirschhausen, Christian von

2005-01-01

This paper analyses the economics of long-term gas contracts under changing institutional conditions, mainly gas sector liberalisation. The paper is motivated by the increasingly tense debate in continental Europe, UK and the US on the security of long-term gas supply. We discuss the main issues regarding long-term contracts, i.e. the changing role of the flexibility clause, the effect of abandoning the destination clause, and the strategic behaviour of producers between long-term sales and spot-sales. The literature suggests consumers and producers benefit from risk hedging through long-term contracts. Furthermore long-term contracts may reduce exercise of market power. Our analysis adds an additional benefit if the long-run demand elasticity is significantly lower than the short-run elasticity, both strategic producers and consumers benefit from lower prices and larger market volume. Some policy implications of the findings are also discussed. (Author)

Long-term trends in submersed aquatic vegetation (SAV) in Chesapeake Bay, USA, related to water quality

Science.gov (United States)

Orth, Robert J.; Williams, Michael R.; Marion, Scott R.; Wilcox, David J.; Carruthers, Tim J.B.; Moore, Kenneth A.; Kemp, W.M.; Dennison, William C.; Rybicki, Nancy B.; Peter Bergstrom,; Batiuk, Richard A.

2010-01-01

Chesapeake Bay supports a diverse assemblage of marine and freshwater species of submersed aquatic vegetation (SAV) whose broad distributions are generally constrained by salinity. An annual aerial SAV monitoring program and a bi-monthly to monthly water quality monitoring program have been conducted throughout Chesapeake Bay since 1984. We performed an analysis of SAV abundance and up to 22 environmental variables potentially influencing SAV growth and abundance (1984-2006). Historically, SAV abundance has changed dramatically in Chesapeake Bay, and since 1984, when SAV abundance was at historic low levels, SAV has exhibited complex changes including long-term (decadal) increases and decreases, as well as some large, single-year changes. Chesapeake Bay SAV was grouped into three broad-scale community-types based on salinity regime, each with their own distinct group of species, and detailed analyses were conducted on these three community-types as well as on seven distinct case-study areas spanning the three salinity regimes. Different trends in SAVabundance were evident in the different salinity regimes. SAV abundance has (a) continually increased in the low-salinity region; (b) increased initially in the medium-salinity region, followed by fluctuating abundances; and (c) increased initially in the high-salinity region, followed by a subsequent decline. In all areas, consistent negative correlations between measures of SAV abundance and nitrogen loads or concentrations suggest that meadows are responsive to changes in inputs of nitrogen. For smaller case-study areas, different trends in SAV abundance were also noted including correlations to water clarity in high-salinity case-study areas, but nitrogen was highly correlated in all areas. Current maximum SAV coverage for almost all areas remain below restoration targets, indicating that SAV abundance and associated ecosystem services are currently limited by continued poor water quality, and specifically high

New Zealand: long-term care in a decade of change.

Science.gov (United States)

Ashton, T

2000-01-01

Long-term care in New Zealand incorporates a mix of public and private funding and provision. After a decade of structural change, the purchasing of almost all publicly funded health and social care is now the responsibility of one central agency. Services for older persons are poorly integrated, and there are problems of access to and quality of some services. Efforts are being made to address these problems. The challenge now is to ensure that this groundwork is not lost amid the turmoil of yet another round of restructuring by an enthusiastic, newly elected government.

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

Directory of Open Access Journals (Sweden)

Lanhui Wang

2017-12-01

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

Salt Marsh development studies at Waquoit Bay, Massachusetts: Influence of geomorphology on long-term plant community structure

Science.gov (United States)

Orson, Richard A.; Howes, Brian L.

1992-11-01

Stochastic events relating to beach formation and inlet dynamics have been the major factors influencing the development of the Waquoit Bay tidal marshes. This results from the physical structure of the Waquoit Bay system where tidal exchange is limited to one or two small inlets and is in contrast to marsh development in nearby Barnstable Marsh where direct unrestricted exchange with Cape Cod Bay has smoothed the effects of stochastic events on vegetation development. We contend that vegetation development in salt marshes where connections to adjacent waters are restricted will be dominated by abiotic factors (e.g. storms, sedimentation rates, etc.) while those marshes directly linked to open bodies of water and where alterations to hydrodynamic factors are gradual, autecological processes (e.g. interspecific competition) will dominate long-term plant community development. The results from the five marsh systems within the Waquoit Bay complex suggest that once a vegetation change occurs the new community tended to persist for long periods of time (100's-1000's years). Stability of the 'new' community appeared to depend upon the stability of the physical structure of the system and/or time between perturbations necessary to allow the slower autecological processes to have a discernable effect. In order for the plant community to persist as long as observed, the vegetation must also be exerting an influence on the processes of development. Increased production of roots and rhizomes and growth characteristics (density of culms) are some of the factors which help to maintain long-term species dominance. It is clear from this investigation that the structure of the plant community at any one point in time is dependent upon numerous factors including historical developmental influences. To properly assess changes to the present plant community or determine recent rates of accretion, historic developmental trends must be considered. The factors that have influenced the

Self-guided Change: The most common form of long-term, maintained health behavior change

Science.gov (United States)

Bishop, F Michler

2018-01-01

Millions of people change risky, health-related behaviors and maintain those changes. However, they often take years to change, and their unhealthy behaviors may harm themselves and others and constitute a significant cost to society. A review—similar in nature to a scoping review—was done of the literature related to long-term health behavior change in six areas: alcohol, cocaine and heroin misuse, gambling, smoking, and overeating. Based on the limited research available, reasons for change and strategies for changing and for maintaining change were also reviewed. Fifty years of research clearly indicate that as people age, in the case of alcohol, heroin and cocaine misuse, smoking, and gambling, 80–90 percent moderate or stop their unhealthy behaviors. The one exception is overeating; only 20 percent maintain their weight loss. Most of these changes, when they occur, appear to be the result of self-guided change. More ways to accelerate self-guided, health-related behavior change need to be developed and disseminated. PMID:29375888

Experimental Forests and climate change: views of long-term employees on ecological change and the role of Experimental Forests and Ranges in understanding and adapting to climate change

Science.gov (United States)

Laurie Yung; Mason Bradbury; Daniel R. Williams

2012-01-01

In this project, we examined the views of 21 long-term employees on climate change in 14 Rocky Mountain Research Station Experimental Forests and Ranges (EFRs). EFRs were described by employees as uniquely positioned to advance knowledge of climate change impacts and adaptation strategies due to the research integrity they provide for long-term studies, the ability to...

Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

Directory of Open Access Journals (Sweden)

Lauren eChaby

2013-07-01

Full Text Available Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid stress hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g. isolation, crowding, cage tilt were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias (F1,12 = 5.000, P < 0.05, altered coping response (T1,14 = 2.216, P = 0.04, and accelerated decision making (T1,14 = 3.245, P = 0.01. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object (T1,14 = 2.240, P = 0.04; T1,14 = 2.419, P = 0.03, respectively. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions. Stress during adolescence also induced short-term changes in the way animals moved around a novel environment.

Long-term bird study records Arctic climate change

Science.gov (United States)

Zielinski, Sarah

Alaska's summer of 2005 was the second warmest on record there, with a record retreat of arctic pack ice. As Alaskan temperatures gradually increase, artic birds, such as the black guillemots of Cooper Island, near Barrow, Alaska, are experiencing drastic habitat changes. Though these small black and white birds—the subjects of a long-term study of climate change—fared better this year than they have in the recent past (due to local cool conditions), they are nonetheless struggling to adapt as their artic island summer home becomes subarctic.George Divokyan ornithologist at the Institute of Arctic Biology, University of Alaska Fairbanks, discovered the Cooper Island colony of guillemots in the early 1970s and has spent every summer since 1975 there studying these birds. He presented his latest research during a 3 November talk in Washington, D.C.

Integrating Social Science into the Long-Term Ecological Research (LTER) Network: Social Dimensions of Ecological Change and Ecological Dimensions of Social Change

Science.gov (United States)

Charles L. Redman; J. Morgan Grove; Lauren H. Kuby; Lauren H. Kuby

2004-01-01

The integration of the social sciences into long-term ecological research is an urgent priority. To address this need, a group of social, earth, and life scientists associated with the National Science Foundation's (NSF) Long-Term Ecological Research (LTER) Network have articulated a conceptual framework for understanding the human dimensions of ecological change...

Enabling long-term oceanographic research: Changing data practices, information management strategies and informatics

Science.gov (United States)

Baker, Karen S.; Chandler, Cynthia L.

2008-09-01

Interdisciplinary global ocean science requires new ways of thinking about data and data management. With new data policies and growing technological capabilities, datasets of increasing variety and complexity are being made available digitally and data management is coming to be recognized as an integral part of scientific research. To meet the changing expectations of scientists collecting data and of data reuse by others, collaborative strategies involving diverse teams of information professionals are developing. These changes are stimulating the growth of information infrastructures that support multi-scale sampling, data repositories, and data integration. Two examples of oceanographic projects incorporating data management in partnership with science programs are discussed: the Palmer Station Long-Term Ecological Research program (Palmer LTER) and the United States Joint Global Ocean Flux Study (US JGOFS). Lessons learned from a decade of data management within these communities provide an experience base from which to develop information management strategies—short-term and long-term. Ocean Informatics provides one example of a conceptual framework for managing the complexities inherent to sharing oceanographic data. Elements are introduced that address the economies-of-scale and the complexities-of-scale pertinent to a broader vision of information management and scientific research.

Surface ozone in China: present-day distribution and long-term changes

Science.gov (United States)

Xu, X.; Lin, W.; Xu, W.

2017-12-01

Reliable knowledge of spatio-temporal variations of surface ozone is highly needed to assess the impacts of ozone on human health, ecosystem and climate. Although regional distributions and trends of surface ozone in European and North American countries have been well characterized, little is known about the variability of surface ozone in many other countries, including China, where emissions of ozone precursors have been changing rapidly in recent decades. Here we present the first comprehensive description of present-day (2013-2017) distribution and long-term changes of surface ozone in mainland China. Recent ozone measurements from China's air quality monitoring network (AQMN) are analyzed to show present-day distributions of a few ozone exposure metrics for urban environment. Long-term measurements of ozone at six background sites, a rural site and an urban are used to study the trends of ozone in background, rural and urban air, respectively. The average levels of ozone at the AQMN sites (mainly urban) are close to those found at many European and North American sites. However, ozone at most of the sites shows very large diurnal and seasonal variations so that ozone nonattainment can occur in many cities, particularly those in the North China Plain (NCP), the south of Northeast China (NEC), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Sichuan Basin-Chongqing region (SCB). In all these regions, particularly in the NCP, the maximum daily 8-h average (MDA8) ozone concentration can significantly exceed the national limit (75 ppb). High annual sum of ozone means over 35 ppb (SOMO35) exist mainly in the NCP, NEC and YRD, with regional averages over 4000 ppb·d. Surface ozone has significantly increased at Waliguan (a baseline site in western China) and Shangdianzi (a background site in the NCP), and decreased in winter and spring at Longfengshan (a background site in Northeast China). No clear trend can be derived from long-term measurements

How will climate change affect the vegetation cycle over France? A generic modeling approach

Directory of Open Access Journals (Sweden)

Nabil Laanaia

2016-01-01

over most of France. This shows that developing in situ soil moisture networks could help monitoring the long-term impacts of climate change.

Analysis of Decadal Vegetation Dynamics Using Multi-Scale Satellite Images

Science.gov (United States)

Chiang, Y.; Chen, K.

2013-12-01

This study aims at quantifying vegetation fractional cover (VFC) by incorporating multi-resolution satellite images, including Formosat-2(RSI), SPOT(HRV/HRG), Landsat (MSS/TM) and Terra/Aqua(MODIS), to investigate long-term and seasonal vegetation dynamics in Taiwan. We used 40-year NDVI records for derivation of VFC, with field campaigns routinely conducted to calibrate the critical NDVI threshold. Given different sensor capabilities in terms of their spatial and spectral properties, translation and infusion of NDVIs was used to assure NDVI coherence and to determine the fraction of vegetation cover at different spatio-temporal scales. Based on the proposed method, a bimodal sequence of intra-annual VFC which corresponds to the dual-cropping agriculture pattern was observed. Compared to seasonal VFC variation (78~90%), decadal VFC reveals moderate oscillations (81~86%), which were strongly linked with landuse changes and several major disturbances. This time-series mapping of VFC can be used to examine vegetation dynamics and its response associated with short-term and long-term anthropogenic/natural events.

Long-term disturbance dynamics and resilience of tropical peat swamp forests.

Science.gov (United States)

Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

2015-01-01

1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude

Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence.

Science.gov (United States)

Chaby, Lauren E; Cavigelli, Sonia A; White, Amanda; Wang, Kayllie; Braithwaite, Victoria A

2013-01-01

Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid "stress" hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision-making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g., isolation, crowding, cage tilt) were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias [F (1, 12) = 5.000, P chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object [T (1, 14) = 2.240, P = 0.04; T (1, 14) = 2.419, P = 0.03, respectively]. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions.

Short-Term and Long-Term Forecasting for the 3D Point Position Changing by Using Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Eleni-Georgia Alevizakou

2018-03-01

Full Text Available Forecasting is one of the most growing areas in most sciences attracting the attention of many researchers for more extensive study. Therefore, the goal of this study is to develop an integrated forecasting methodology based on an Artificial Neural Network (ANN, which is a modern and attractive intelligent technique. The final result is to provide short-term and long-term forecasts for point position changing, i.e., the displacement or deformation of the surface they belong to. The motivation was the combination of two thoughts, the insertion of the forecasting concept in Geodesy as in the most scientific disciplines (e.g., Economics, Medicine and the desire to know the future position of any point on a construction or on the earth’s crustal. This methodology was designed to be accurate, stable and general for different kind of geodetic data. The basic procedure consists of the definition of the forecasting problem, the preliminary data analysis (data pre-processing, the definition of the most suitable ANN, its evaluation using the proper criteria and finally the production of forecasts. The methodology gives particular emphasis on the stages of the pre-processing and the evaluation. Additionally, the importance of the prediction intervals (PI is emphasized. A case study, which includes geodetic data from the year 2003 to the year 2016—namely X, Y, Z coordinates—is implemented. The data were acquired by 1000 permanent Global Navigation Satellite System (GNSS stations. During this case study, 2016 ANNs—with different hyper-parameters—are trained and tested for short-term forecasting and 2016 for long-term forecasting, for each of the GNSS stations. In addition, other conventional statistical forecasting methods are used for the same purpose using the same data set. Finally the most appropriate Non-linear Autoregressive Recurrent network (NAR or Non-linear Autoregressive with eXogenous inputs (NARX for the forecasting of 3D point

Long-term developmental changes in children’s lower-order big five personality facets

NARCIS (Netherlands)

de Haan, A.; de Pauw, S.; van den Akker, A.; Deković, M.; Prinzie, P.

2017-01-01

Objective This study examined long-term developmental changes in mother-rated lower-order facets of children's Big Five dimensions. Method Two independent community samples covering early childhood (2–4.5 years; N = 365, 39% girls) and middle childhood to the end of middle adolescence (6–17 years;

Long-term developmental changes in children’s lower-order Big Five personality facets

NARCIS (Netherlands)

de Haan, A.D.; de Pauw, S.; van den Akker, A.L.; Dekovic, M.; Prinzie, Peter

2017-01-01

Objective This study examined long-term developmental changes in mother-rated lower-order facets of children's Big Five dimensions. Method Two independent community samples covering early childhood (2–4.5 years; N = 365, 39% girls) and middle childhood to the end of middle adolescence (6–17 years;

Long-term air temperature changes in a Central European sedge-grass marsh

Czech Academy of Sciences Publication Activity Database

Dušek, Jiří; Stellner, Stanislav; Komárek, A.

2013-01-01

Roč. 6, č. 2 (2013), s. 182-190 ISSN 1936-0584 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŽP(CZ) SP/2D1/93/07 Institutional research plan: CEZ:AV0Z60870520 Keywords : Carex acuta * fen * wetland * long-term monitoring * global change Subject RIV: EH - Ecology, Behaviour Impact factor: 2.634, year: 2013

Comparison of Modeling Grassland Degradation with and without Considering Localized Spatial Associations in Vegetation Changing Patterns

Directory of Open Access Journals (Sweden)

Yuwei Wang

2018-01-01

Full Text Available Grassland ecosystems worldwide are confronted with degradation. It is of great importance to understand long-term trajectory patterns of grassland vegetation by advanced analytical models. This study proposes a new approach called a binary logistic regression model with neighborhood interactions, or BLR-NIs, which is based on binary logistic regression (BLR, but fully considers the spatio-temporally localized spatial associations or characterization of neighborhood interactions (NIs in the patterns of grassland vegetation. The BLR-NIs model was applied to a modeled vegetation degradation of grasslands in the Xilin river basin, Inner Mongolia, China. Residual trend analysis on the normalized difference vegetation index (RESTREND-NDVI, which excluded the climatic impact on vegetation dynamics, was adopted as a preprocessing step to derive three human-induced trajectory patterns (vegetation degradation, vegetation recovery, and no significant change in vegetation during two consecutive periods, T1 (2000–2008 and T2 (2007–2015. Human activities, including livestock grazing intensity and transportation accessibility measured by road network density, were included as explanatory variables for vegetation degradation, which was defined for locations if vegetation recovery or no significant change in vegetation in T1 and vegetation degradation in T2 were observed. Our work compared the results of BLR-NIs and the traditional BLR model that did not consider NIs. The study showed that: (1 both grazing intensity and road density had a positive correlation to vegetation degradation based on the traditional BLR model; (2 only road density was found to positively correlate to vegetation degradation by the BLR-NIs model; NIs appeared to be critical factors to predict vegetation degradation; and (3 including NIs in the BLR model improved the model performance substantially. The study provided evidence for the importance of including localized spatial

Neural Rhythms of Change: Long-Term Improvement after Successful Treatment in Children with Disruptive Behavior Problems

Directory of Open Access Journals (Sweden)

Steven Woltering

2015-01-01

Full Text Available Neural changes were investigated for children with disruptive behavior problems one year after a treatment program ended. Thirty-nine children and their parents visited the research lab before, after, and a year after treatment ended. During those lab visits, electroencephalography (EEG was recorded during a challenging Go/No-go task. Treatment consisted of intensive 14-week combined cognitive behavioral therapy and parent management training sessions. For the analysis, participants were divided into long-term improvers (IMPs and long-term nonimprovers (NIMPs based on changes in their externalizing problem scores. The results showed early no-go theta power (4–8 Hz, 100–250 ms decreased for long-term IMPs compared to NIMPs. When participants were divided based on changes in their comorbid internalizing symptoms, effects were stronger and reductions in theta power were found for early as well as later phases (250–650 ms. We provided preliminary evidence that theta power is a useful neural measure to trace behavioral change linked to improved self-regulation even up to a year after treatment ended. Results may have implications for the characterization of children with disruptive behavior problems and may lead to the development of novel markers of treatment success.

The long-term climate change task of the Hanford permanent isolation barrier development program

International Nuclear Information System (INIS)

1994-01-01

The Hanford Site Permanent Isolation Barrier Development Program is developing an in-place disposal capability for low-level nuclear waste for the US Department of Energy at the Hanford Site in southeastern Washington State. Layered earthen and engineered barriers are being developed that will function in what is currently a semiarid environment (mean annual precipitation and temperature of 16 cm and 11.8 degrees C, respectively) for at least 1,000 yr by limiting the infiltration of water through the waste. The Long-Term Climate Change Task has specific goals of (1) obtaining defensible probabilistic projections of the long-term climate variability in the Hanford Site region at many different time scales into the future; (2) developing several test-case climate scenarios that bracket the range of potential future climate, including both greenhouse warming and cycling into another ice age; and (3) using the climate scenarios both to test and to model protective barrier performance. Results from the Carp Lake Pollen Coring Project indicate that for the last approximately 100,000 yr the Columbia River Basin's long-term range of mean annual precipitation ranged from 25%--50% below to 28% above modern levels, while temperature has ranged from 7 degrees C--10 degrees C below to 2 degrees C above modern levels. This long record provides confidence that such a range should bracket potential natural climate change even if the earth cycles back into another Ice Age in the next few millennia

Assessment of vegetation trends in drylands from time series of earth observation data

NARCIS (Netherlands)

Fensholt, R.; Horion, S.; Tagesson, T.; Ehammer, A.; Grogan, K.; Tian, F.; Huber, S.; Verbesselt, J.; Prince, S.D.; Tucker, C.J.; Rasmussen, K.

2015-01-01

This chapter summarizes approaches to the detection of dryland vegetation change and methods for observing spatio-temporal trends from space. An overview of suitable long-term Earth Observation (EO) based datasets for assessment of global dryland vegetation trends is provided and a status map of

Long-term outcome of biopsy-proven, frequently relapsing minimal-change nephrotic syndrome in children.

NARCIS (Netherlands)

Kyrieleis, H.A.; Lowik, M.M.; Pronk, I.; Cruysberg, J.R.M.; Kremer, J.A.M.; Oyen, W.J.G.; Heuvel, L.P.W.J. van den; Wetzels, J.F.M.; Levtchenko, E.N.

2009-01-01

BACKGROUND AND OBJECTIVES: Frequently relapsing and steroid-dependent minimal-change nephrotic syndrome (MCNS) that originates in childhood can persist after puberty in >20% of patients. These patients require immunosuppressive treatment during several decades of their life. We examined long-term

Metamemory ratings predict long-term changes in reactivated episodic memories

Directory of Open Access Journals (Sweden)

Amnon eYacoby

2015-02-01

Full Text Available Reactivation of long-term memory can render the memory item temporarily labile, offering an opportunity to modify it via behavioral or pharmacological intervention. Declarative memory reactivation is accompanied by a metamemory ability to subjectively assess the knowledge available concerning the target item (Feeling of knowing, FOK. We set out to examine whether FOK can predict the extent of change of long-term episodic memories by post-retrieval manipulations. To this end, participants watched a short movie and immediately thereafter tested on their memory for it. A day later, they were reminded of that movie, and either immediately or one day later, were presented with a second movie. The reminder phase consisted of memory cues to which participants were asked to judge their FOK regarding the original movie. The memory performance of participants to whom new information was presented immediately after reactivating the original episode corresponded to the degree of FOK ratings upon reactivation such that the lower their FOK, the less their memory declined. In contrast, no relation was found between FOK and memory strength for those who learned new information one day after the reminder phase. Our findings suggest that the subjective accessibility of reactivated memories may determine the extent to which new information might modify those memories.

Long-term stabilization of uranium mill tailings: effects of rock material on vegetation on soil moisture

International Nuclear Information System (INIS)

Beedlow, P.A.; Carlile, D.W.

1982-11-01

A field-scale experiment was conducted to investigate the effects of pit-run rock and washed cobble on vegetation and soil moisture. The success of various seed mixtures, transplanting and irrigation levels were evaluated. Total cover changed negligibly from the first growing season to the next, but the structure of the vegetation changed markedly. Moderate levels of irrigation increased the establishment of perennial grasses and shrubs. Rock placed on the surface prior to planting resulted in increased cover of weeds, shrubs and forbs and decreased grass cover relative to soil without surface rock. The most successful seed mixture was one of predominantly shrub and forb species adapted to the local environment. No significant differences in soil moisture were found between surface cover types. 6 references, 7 figures

Minor long-term changes in weight have beneficial effects on insulin sensitivity and beta-cell function in obese subjects

DEFF Research Database (Denmark)

Rosenfalck, A M; Hendel, Helle Westergren; Rasmussen, M H

2002-01-01

To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function.......To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function....

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences

Energy Technology Data Exchange (ETDEWEB)

Beck, Pieter S A; Goetz, Scott J, E-mail: pbeck@whrc.org [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States)

2011-10-15

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differences are discussed.

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences

International Nuclear Information System (INIS)

Beck, Pieter S A; Goetz, Scott J

2011-01-01

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differences are discussed.

Scientific Understanding from Long Term Observations: Insights from the Long Term Ecological Research (LTER) Program

Science.gov (United States)

Gosz, J.

2001-12-01

The network dedicated to Long Term Ecological Research (LTER) in the United States has grown to 24 sites since it was formed in 1980. Long-term research and monitoring are performed on parameters thatare basic to all ecosystems and are required to understand patterns, processes, and relationship to change. Collectively, the sites in the LTER Network provide opportunities to contrast marine, coastal, and continental regions, the full range of climatic gradients existing in North America, and aquatic and terrestrial habitats in a range of ecosystem types. The combination of common core areas and long-term research and monitoring in many habitats have allowed unprecedented abilities to understand and compare complex temporal and spatial dynamics associated with issues like climate change, effects of pollution, biodiversity and landuse. For example, McMurdo Dry Valley in the Antarctic has demonstrated an increase in glacier mass since 1993 which coincides with a period of cooler than normal summers and more than average snowfall. In contrast, the Bonanza Creek and Toolik Lake sites in Alaska have recorded a warming period unprecedented in the past 200 years. Nitrogen deposition effects have been identified through long-term watershed studies on biogeochemical cycles, especially at Coweeta Hydrological Lab, Harvard Forest, and the Hubbard Brook Experimental Forest. In aquatic systems, such as the Northern Temperate Lakes site, long-term data revealed time lags in effects of invaders and disturbance on lake communities. Biological recovery from an effect such as lake acidification was shown to lag behind chemical recovery. The long-term changes documented over 2 decades have been instrumental in influencing management practices in many of the LTER areas. In Puerto Rico, the Luquillo LTER demonstrated that dams obstruct migrations of fish and freshwater shrimp and water abstraction at low flows can completely obliterate downstream migration of juveniles and damage

The long-term effect of screening and lifestyle counseling on changes in physical activity and diet

DEFF Research Database (Denmark)

Baumann, Sophie; Toft, Ulla; Aadahl, Mette

2015-01-01

five years, all participants in the intervention group (n = 6,091) received individual lifestyle counseling; participants at high risk of ischemic heart disease - according to pre-specified criteria - were also offered group-based counseling. The control group (n = 3,324) was followed by questionnaires.......6 min/week, p = 0.003) and less intake of saturated fat (OR = 0.31, 95% CI: 0.17-0.56) than the control group. Improvements in the intake of vegetables and fish achieved during the intervention were not maintained in the longer-term. CONCLUSIONS: Screening and lifestyle counseling had sustained effects....... Both groups were followed one, three, five, and ten years after baseline. Changes in physical activity and dietary habits (intake of vegetables, fruit, fish, and saturated fat) during and after the intervention were investigated using random-coefficient models. RESULTS: Five years after...

Sleep facilitates long-term face adaptation

OpenAIRE

Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

2013-01-01

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted imag...

Vegetation Response to Climate Change in the Southern Part of Qinghai-Tibet Plateau at Basinal Scale

Science.gov (United States)

Liu, X.; Liu, C.; Kang, Q.; Yin, B.

2018-04-01

Global climate change has significantly affected vegetation variation in the third-polar region of the world - the Qinghai-Tibet Plateau. As one of the most important indicators of vegetation variation (growth, coverage and tempo-spatial change), the Normalized Difference Vegetation Index (NDVI) is widely employed to study the response of vegetation to climate change. However, a long-term series analysis cannot be achieved because a single data source is constrained by time sequence. Therefore, a new framework was presented in this paper to extend the product series of monthly NDVI, taking as an example the Yarlung Zangbo River Basin, one of the most important river basins in the Qinghai-Tibet Plateau. NDVI products were acquired from two public sources: Global Inventory Modeling and Mapping Studies (GIMMS) Advanced Very High Resolution Radiometer (AVHRR) and Moderate-Resolution Imaging spectroradiometer (MODIS). After having been extended using the new framework, the new time series of NDVI covers a 384 months period (1982-2013), 84 months longer than previous time series of NDVI product, greatly facilitating NDVI related scientific research. In the new framework, the Gauss Filtering Method was employed to filter out noise in the NDVI product. Next, the standard method was introduced to enhance the comparability of the two data sources, and a pixel-based regression method was used to construct NDVI-extending models with one pixel after another. The extended series of NDVI fit well with original AVHRR-NDVI. With the extended time-series, temporal trends and spatial heterogeneity of NDVI in the study area were studied. Principal influencing factors on NDVI were further determined. The monthly NDVI is highly correlated with air temperature and precipitation in terms of climatic change wherein the spatially averaged NDVI slightly increases in the summer and has increased in temperature and decreased in precipitation in the 32 years period. The spatial heterogeneity of

Enabling Long-Term Earth Science Research: Changing Data Practices (Invited)

Science.gov (United States)

Baker, K. S.

2013-12-01

Data stewardship plans are shaped by our shared experiences. As a result, community engagement and collaborative activities are central to the stewardship of data. Since modes and mechanisms of engagement have changed, we benefit from asking anew: ';Who are the communities?' and ';What are the lessons learned?'. Data stewardship with its long-term care perspective, is enriched by reflection on community experience. This presentation draws on data management issues and strategies originating from within long-term research communities as well as on recent studies informed by library and information science. Ethnographic case studies that capture project activities and histories are presented as resources for comparative analysis. Agency requirements and funding opportunities are stimulating collaborative endeavors focused on data re-use and archiving. Research groups including earth scientists, information professionals, and data systems designers are recognizing the possibilities for new ways of thinking about data in the digital arena. Together, these groups are re-conceptualizing and reconfiguring for data management and data curation. A differentiation between managing data for local use and production of data for re-use remotely in locations and fields remote from the data origin is just one example of the concepts emerging to facilitate development of data management. While earth scientists as data generators have the responsibility to plan new workflows and documentation practices, data and information specialists have responsibility to promote best practices as well as to facilitate the development of community resources such as controlled vocabularies and data dictionaries. With data-centric activities and changing data practices, the potential for creating dynamic community information environments in conjunction with development of data facilities exists but remains elusive.

Changes in vegetation phenology are not reflected in atmospheric CO2 and 13 C/12 C seasonality.

Science.gov (United States)

Gonsamo, Alemu; D'Odorico, Petra; Chen, Jing M; Wu, Chaoyang; Buchmann, Nina

2017-10-01

Northern terrestrial ecosystems have shown global warming-induced advances in start, delays in end, and thus increased lengths of growing season and gross photosynthesis in recent decades. The tradeoffs between seasonal dynamics of two opposing fluxes, CO 2 uptake through photosynthesis and release through respiration, determine the influence of the terrestrial ecosystem on the atmospheric CO 2 and 13 C/ 12 C seasonality. Here, we use four CO 2 observation stations in the Northern Hemisphere, namely Alert, La Jolla, Point Barrow, and Mauna Loa Observatory, to determine how changes in vegetation productivity and phenology, respiration, and air temperature affect both the atmospheric CO 2 and 13 C/ 12 C seasonality. Since the 1960s, the only significant long-term trend of CO 2 and 13 C/ 12 C seasonality was observed at the northern most station, Alert, where the spring CO 2 drawdown dates advanced by 0.65 ± 0.55 days yr -1 , contributing to a nonsignificant increase in length of the CO 2 uptake period (0.74 ± 0.67 days yr -1 ). For Point Barrow station, vegetation phenology changes in well-watered ecosystems such as the Canadian and western Siberian wetlands contributed the most to 13 C/ 12 C seasonality while the CO 2 seasonality was primarily linked to nontree vegetation. Our results indicate significant increase in the Northern Hemisphere soil respiration. This means, increased respiration of 13 C depleted plant materials cancels out the 12 C gain from enhanced vegetation activities during the start and end of growing season. These findings suggest therefore that parallel warming-induced increases both in photosynthesis and respiration contribute to the long-term stability of CO 2 and 13 C/ 12 C seasonality under changing climate and vegetation activity. The summer photosynthesis and the soil respiration in the dormant seasons have become more vigorous which lead to increased peak-to-through CO 2 amplitude. As the relative magnitude of the increased

The Impact of Long-Term Climate Change on Nitrogen Runoff at the Watershed Scale.

Science.gov (United States)

Dorley, J.; Duffy, C.; Arenas Amado, A.

2017-12-01

The impact of agricultural runoff is a major concern for water quality of mid-western streams. This concern is largely due to excessive use of agricultural fertilizer, a major source of nutrients in many Midwestern watersheds. In order to improve water quality in these watersheds, understanding the long-term trends in nutrient concentration and discharge is an important water quality problem. This study attempts to analyze the role of long-term temperature and precipitation on nitrate runoff in an agriculturally dominated watershed in Iowa. The approach attempts to establish the concentration-discharge (C-Q) signature for the watershed using time series analysis, frequency analysis and model simulation. The climate data is from the Intergovernmental Panel on Climate Change (IPCC), model GFDL-CM3 (Geophysical Fluid Dynamic Laboratory Coupled Model 3). The historical water quality data was made available by the IIHR-Hydroscience & Engineering at the University of Iowa for the clear creek watershed (CCW). The CCW is located in east-central Iowa. The CCW is representative of many Midwestern watersheds with humid-continental climate with predominantly agricultural land use. The study shows how long-term climate changes in temperature and precipitation affects the C-Q dynamics and how a relatively simple approach to data analysis and model projections can be applied to best management practices at the site.

Evaluating temporal consistency of long-term global NDVI datasets for trend analysis

DEFF Research Database (Denmark)

Tian, Feng; Fensholt, Rasmus; Verbesselt, Jan

2015-01-01

-sensor NDVI time series by analyzing the co-occurrence between breaks in the NDVI time series and sensor shifts from GIMMS3g (Global Inventory Modeling and Mapping Studies 3rd generation), VIP3 (Vegetation Index and Phenology version 3), LTDR4 (Long Term Data Record version 4) and SPOT-VGT (Système Pour l......, potentially introducing uncertainties in NDVI trend analysis. Platform/sensor change from VGT-1 to VGT-2 is found to cause a significant positive break in the SPOT-VGT NDVI time series. Potential artifacts exist in humid, dry-subhumid, semi-arid and hyper-arid regions of GIMMS3g NDVI, whereas no signs...

Long-term changes in flood event patterns due to changes in hydrological distribution parameters in a rural-urban catchment, Shikoku, Japan

Science.gov (United States)

Mouri, Goro; Kanae, Shinjiro; Oki, Taikan

2011-07-01

This article describes the principal control parameters of flood events and precipitation and the relationships between corresponding hydrologic and climatologic parameters. The long-term generation of runoff and associated processes is important in understanding floods and droughts under changes in climate and land use. This study presents detailed analyses of flood events in a coastal amphitheatre catchment with a total area of 445 km 2 in western Japan, followed by analyses of flood events in both urban and forest areas. Using long-term (1962 to 2002) hydrological and climatological data from the Ministry of Land, Infrastructure and Transport, Japan, the contributions of precipitation, river discharge, temperature, and relative humidity to flood events were analysed. Flood events could be divided into three types with respect to hydrologic and climatologic principal control parameters: the long-term tendency; medium-term changes as revealed by hydrographs and hyetographs of high-intensity events such as the relative precipitation, river discharge, and temperature; and large events, as shown by the flow-duration curve, with each cluster having particular characteristics. River discharge showed a decreasing tendency of flow quantity during small rainfall events of less than 100 mm/event from the 1980s to the present. An approximately 7% decrease from 44.8 to 37.3% occurred in the percentage of river water supplied by precipitation in the years after the 1980s. For the medium-term changes, no marked change occurred in the flow quantity of the peak point over time in event hydrographs. However, flow quantities before and after the peak tended to decrease by 1 to 2 m 3/s after the 1980s. Theoretical considerations with regard to the influence of hydrologic and climatologic parameters on flood discharge are discussed and examined in terms of observational data. These findings provide a sound foundation for use in hydrological catchment modelling.

Nile Basin Vegetation Response and Vulnerability to Climate Change: A Multi-Sensor Remote Sensing Approach

Science.gov (United States)

Yitayew, M.; Didan, K.; Barreto-munoz, A.

2013-12-01

The Nile Basin is one of the world's water resources hotspot that is home to over 437 million people in ten riparian countries with 54% or 238 millions live directly within the basin. The basin like all other basins of the world is facing water resources challenges exacerbated by climate change and increased demand. Nowadays any water resource management action in the basin has to assess the impacts of climate change to be able to predict future water supply and also to help in the negotiation process. Presently, there is a lack of basin wide weather networks to understand sensitivity of the vegetation cover to the impacts of climate change. Vegetation plays major economic and ecological functions in the basin and provides key services ranging from pastoralism, agricultural production, firewood, habitat and food sources for the rich wildlife, as well as a major role in the carbon cycle and climate regulation of the region. Under the threat of climate change and the incessant anthropogenic pressure the distribution and services of the region's ecosystems are projected to change The goal of this work is to assess and characterize how the basin vegetation productivity, distribution, and phenology have changed over the last 30+ years and what are the key climatic drivers of this change. This work makes use of a newly generated multi-sensor long-term land surface data set about vegetation and phenology. Vegetation indices derived from remotely sensed surface reflectance data are commonly used to characterize phenology or vegetation dynamics accurately and with enough spatial and temporal resolution to support change detection. We used more than 30 years of vegetation index and growing season data from AVHRR and MODIS sensors compiled by the Vegetation Index and Phenology laboratory (VIP LAB) at the University of Arizona. Available climate data about precipitation and temperature for the corresponding 30 years period is also used for this analysis. We looked at the

Natural gas market assessment: Long-term Canadian natural gas contracts

International Nuclear Information System (INIS)

1992-08-01

A descriptive analysis is presented of the changes which have occurred and the developing trends in the long-term Canadian contracts governing the sale of western Canadian gas into the domestic and export markets from 1985 to 1991. The report is limited to domestic and export contracts for Canadian gas and does not include imported gas under contract. Contract structures prior to deregulation, the changing role of long-term contracts, size and duration of long-term contracts, and terms and conditions of long-term contracts are discussed. Important changes since the mid-1980s include: increased flexibility in long-term contracts enabling the parties to respond more readily to changing supply and demand conditions; greater balance between the buyer's obligation to purchase and the seller's obligation to deliver; flexible and increasingly simple pricing terms that track competitive market conditions; shorter contract terms; reduced contract volumes as smaller end-users and producer/marketers enter the market; and unbundling of gas sales and transportation service providing a wider range of contracting choices and options. 36 figs., 2 tabs

Long-term fashion forecast based on the sociological model of cyclic changes

Directory of Open Access Journals (Sweden)

А V Lebsak-Kleimans

2010-09-01

Full Text Available The concepts of social changes coined by classical sociology may be incorporated as the basis for the elaboration of social prognostication models which, in turn, may suitable for fashion forecast applied technologies development. In the framework of the given paper fashion is described as the phenomenon of collective behaviour. The principles of long-term fashion trends forecast are shown to be in line with the concepts of cyclic development.

Medium- and Long-term Prediction of LOD Change by the Leap-step Autoregressive Model

Science.gov (United States)

Wang, Qijie

2015-08-01

The accuracy of medium- and long-term prediction of length of day (LOD) change base on combined least-square and autoregressive (LS+AR) deteriorates gradually. Leap-step autoregressive (LSAR) model can significantly reduce the edge effect of the observation sequence. Especially, LSAR model greatly improves the resolution of signals’ low-frequency components. Therefore, it can improve the efficiency of prediction. In this work, LSAR is used to forecast the LOD change. The LOD series from EOP 08 C04 provided by IERS is modeled by both the LSAR and AR models. The results of the two models are analyzed and compared. When the prediction length is between 10-30 days, the accuracy improvement is less than 10%. When the prediction length amounts to above 30 day, the accuracy improved obviously, with the maximum being around 19%. The results show that the LSAR model has higher prediction accuracy and stability in medium- and long-term prediction.

Long Term Storage of cytogenetic changes in liquidators of Chernobyl

International Nuclear Information System (INIS)

Karpov, V. B.

2004-01-01

At present chromosome aberration analysis in lymphocytes as well as micronucleus assay are most reliable methods of bio indication of radiation effects. The problem of persistent of cytogenetic changes during the long term after exposure is very important. The cytogenetic studies of liquidators residents of St. Petersburg and region revealed that the average chromosome aberration rate 4-5 years after the accident constitutes 4.94±0.38, number of aberrant cells was 4.82±0.36, dicentrics -0.23±0.10 per 100 cells, micronucleus number -46.1±2.1 per 100 cells that is significantly higher than in control group. dispersion analysis confirms the reported level of external exposure effects on chromosome aberration rate (?=0.04) in this group of liquidators. In 73 persons from the group of high risk participants of nuclear tests, nuclear submarine personnel 8-45 years after average number of chromosome aberrations was 6.5±0.32; dicentrics - 0.64±0.10, centric rings- 0.04±0.02 per 100 cells, for micronuclei -51.4±2.82 per thousand cells, that is significantly higher than in control group (p<0.01). In 45.2% cases the aberration markers (disentrics and centric rings) were found. The late cytogenetic effects were observed after decades and possibility to use these indicators for long term diagnosis is now under consideration. (Author)

Long-term herbarium records reveal temperature-dependent changes in flowering phenology in the southeastern USA

Science.gov (United States)

Park, Isaac W.; Schwartz, Mark D.

2015-03-01

In recent years, a growing body of evidence has emerged indicating that the relationship between flowering phenology and climate may differ throughout various portions of the growing season. These differences have resulted in long-term changes in flowering synchrony that may alter the quantity and diversity of pollinator attention to many species, as well as altering food availability to pollenivorous and nectarivorous animal species. However, long-term multi-season records of past flowering timing have primarily focused on temperate environments. In contrast, changes in flowering phenology within humid subtropical environments such as the southeastern USA remain poorly documented. This research uses herbarium-based methods to examine changes in flowering time across 19,328 samples of spring-, summer-, and autumn-flowering plants in the southeastern USA from the years 1951 to 2009. In this study, species that flower near the onset of the growing season were found to advance under increasing mean March temperatures (-3.391 days/°C, p = 0.022). No long-term advances in early spring flowering or spring temperature were detected during this period, corroborating previous phenological assessments for the southeastern USA. However, late spring through mid-summer flowering exhibited delays in response to higher February temperatures (over 0.1.85 days/°C, p ≤ 0.041 in all cases). Thus, it appears that flowering synchrony may undergo significant restructuring in response to warming spring temperatures, even in humid subtropical environments.

Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions.

Science.gov (United States)

Ellingsen, Kari E; Yoccoz, Nigel G; Tveraa, Torkild; Hewitt, Judi E; Thrush, Simon F

2017-10-30

The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability of data. In Norway, the authorities require environmental monitoring of the impacts of the offshore petroleum industry on the Norwegian continental shelf, and in 1996, a large-scale regional environmental monitoring program was established. As a case study, we used a sub-set of data from this monitoring to explore concepts regarding best practices for long-term environmental monitoring. Specifically, we examined data from physical and chemical sediment samples and benthic macroinvertebrate assemblages from 11 stations from six sampling occasions during the period 1996-2011. Despite the established quality assessment and quality control protocols for this monitoring program, we identified several data challenges, such as missing values and outliers, discrepancies in variable and station names, changes in procedures without calibration, and different taxonomic resolution. Furthermore, we show that the use of different laboratories over time makes it difficult to draw conclusions with regard to some of the observed changes. We offer recommendations to facilitate comparison of data over time. We also present a new procedure to handle different taxonomic resolution, so valuable historical data is not discarded. These topics have a broader relevance and application than for our case study.

Long-term sustainability of a worksite canteen intervention of serving more fruit and vegetables

DEFF Research Database (Denmark)

Thorsen, Anne Vibeke; Lassen, Anne Dahl; Tetens, Inge

2010-01-01

Objective: To analyse the 5-year sustainability of a worksite canteen intervention of serving more fruit and vegetables (F&V). Design: Average F&V consumption per customer per meal per day was assessed in five worksite canteens by weighing F&V served and subtracting waste. Data were collected by ...... where the participatory and empowering approach, self-monitoring, environmental change, dialogue with suppliers and networking among worksite canteens are applied....

Global changes in dryland vegetation dynamics (1988–2008 assessed by satellite remote sensing: comparing a new passive microwave vegetation density record with reflective greenness data

Directory of Open Access Journals (Sweden)

N. Andela

2013-10-01

Full Text Available Drylands, covering nearly 30% of the global land surface, are characterized by high climate variability and sensitivity to land management. Here, two satellite-observed vegetation products were used to study the long-term (1988–2008 vegetation changes of global drylands: the widely used reflective-based Normalized Difference Vegetation Index (NDVI and the recently developed passive-microwave-based Vegetation Optical Depth (VOD. The NDVI is sensitive to the chlorophyll concentrations in the canopy and the canopy cover fraction, while the VOD is sensitive to vegetation water content of both leafy and woody components. Therefore it can be expected that using both products helps to better characterize vegetation dynamics, particularly over regions with mixed herbaceous and woody vegetation. Linear regression analysis was performed between antecedent precipitation and observed NDVI and VOD independently to distinguish the contribution of climatic and non-climatic drivers in vegetation variations. Where possible, the contributions of fire, grazing, agriculture and CO2 level to vegetation trends were assessed. The results suggest that NDVI is more sensitive to fluctuations in herbaceous vegetation, which primarily uses shallow soil water, whereas VOD is more sensitive to woody vegetation, which additionally can exploit deeper water stores. Globally, evidence is found for woody encroachment over drylands. In the arid drylands, woody encroachment appears to be at the expense of herbaceous vegetation and a global driver is interpreted. Trends in semi-arid drylands vary widely between regions, suggesting that local rather than global drivers caused most of the vegetation response. In savannas, besides precipitation, fire regime plays an important role in shaping trends. Our results demonstrate that NDVI and VOD provide complementary information and allow new insights into dryland vegetation dynamics.

Dynamic response of land use and river nutrient concentration to long-term climatic changes.

Science.gov (United States)

Bussi, Gianbattista; Janes, Victoria; Whitehead, Paul G; Dadson, Simon J; Holman, Ian P

2017-07-15

The combined indirect and direct impacts of land use change and climate change on river water quality were assessed. A land use allocation model was used to evaluate the response of the catchment land use to long-term climatic changes. Its results were used to drive a water quality model and assess the impact of climatic alterations on freshwater nitrate and phosphorus concentrations. Climatic projections were employed to estimate the likelihood of such response. The River Thames catchment (UK) was used as a case-study. If land use is considered as static parameter, according to the model results, climate change alone should reduce the average nitrate concentration, although just by a small amount, by the 2050s in the Lower Thames, due to reduced runoff (and lower export of nitrate from agricultural soils) and increased instream denitrification, and should increase the average phosphorus concentration by 12% by the 2050s in the Lower Thames, due to a reduction of the effluent dilution capacity of the river flow. However, the results of this study also show that these long-term climatic alterations are likely to lead to a reduction in the arable land in the Thames, replaced by improved grassland, due to a decrease in agriculture profitability in the UK. Taking into account the dynamic co-evolution of land use with climate, the average nitrate concentration is expected to be decreased by around 6% by the 2050s in both the upper and the lower Thames, following the model results, and the average phosphorus concentration increased by 13% in the upper Thames and 5% in the lower Thames. On the long term (2080s), nitrate is expected to decrease by 9% and 8% (upper and lower Thames respectively) and phosphorus not to change in the upper thames and increase by 5% in the lower Thames. Copyright © 2017 Elsevier B.V. All rights reserved.

Resilience of Mediterranean terrestrial ecosystems and fire severity in semiarid areas: Responses of Aleppo pine forests in the short, mid and long term.

Science.gov (United States)

González-De Vega, S; De Las Heras, J; Moya, D

2016-12-15

In recent decades, the fire regime of the Mediterranean Basin has been disturbed by various factors: climate change; forest management policies; land cover; changed landscape. Size and severity have notably increased, which in turn have increased large fires events with >500ha burned (high severity). In spite of Mediterranean ecosystems' high resilience to fire, these changes have implied more vulnerability and reduced natural recovery with irreparable long-term negative effects. Knowledge of the response of ecosystems to increasing severity, mainly in semiarid areas, is still lacking, which is needed to rehabilitate and restore burned areas. Our approach assessed the resilience concept by focusing on the recovery of ecosystem functions and services, measured as changes in the composition and diversity of plant community vegetation and structure. This will be validated in the long term as a model of ecosystem response. Also, depending on the pre-fire characteristics of vegetation, fire severity and the post-fire management, this approach will lead to tools that can be applied to implement post-fire restoration efforts in order to help decision making in planning activities. Regarding Mediterranean ecosystems' ability to recover after wildfires, this study concludes that pre-fire communities are resilient in these fire-prone areas, but the window for natural recovery in semiarid areas of Aleppo pine forest in SE Iberian Peninsula varied from 3 to 15 post-fire years. Fire severity was also key for effects on the ecosystem: the vegetation types of areas burned with low and medium severity recovered naturally, while those areas with a high-severity burn induced shrublands. We concluded that very strong regeneration activity exists in the short term, and that the negative effects of medium- and high-severity fire are evidenced in the mid and long term, which affect natural recovery. Adaptive forest management to rehabilitate and restore burned Mediterranean ecosystems

Drivers of inter-annual variation and long-term change in High-Arctic spider species abundances

DEFF Research Database (Denmark)

Bowden, Joseph J.; Hansen, Oskar L. P.; Olsen, Kent

2018-01-01

Understanding how species abundances vary in space and time is a central theme in ecology, yet there are few long-term field studies of terrestrial invertebrate abundances and the determinants of their dynamics. This is particularly relevant in the context of rapid climate change occurring...... in the Arctic. Arthropods can serve as strong indicators of ecosystem change due to their sensitivity to increasing temperatures and other environmental variables. We used spider samples collected by pitfall trapping from three different habitats (fen, mesic and arid heath) in High-Arctic Greenland to assess...... interpretation of long-term trends. We used model selection to determine which climatic variables and/or previous years’ abundance best explained annual variation in species abundances over this period. We identified and used 28 566 adult spiders that comprised eight species. Most notably, the abundances of some...

Vegetation response to climate change : implications for Canada's conservation lands

Energy Technology Data Exchange (ETDEWEB)

Scott, D. [Environment Canada, Ottawa, ON (Canada). Adaptation and Impact Research Group; Lemieux, C. [Waterloo Univ., ON (Canada). Dept. of Geography

2003-05-01

Studies have shown that Canada's national parks are vulnerable to the impacts of climate change. A wide range of biophysical climate change impacts could affect the integrity of conservation lands in each region of Canada. This report examines the potential impact of climate change on landscape alterations and vegetation distribution in Canada's wide network of conservation lands. It also presents several ways to integrate climate change into existing conservation policy and adaptation strategies. Canada's conservation lands include provincial parks, migratory bird sanctuaries, national wildlife areas and wildlife protected areas. This is the first study to examine biome changes by applying an equilibrium Global Vegetation Model (GVM) to Canada's network of national park systems. Some of the policy and planning challenges posed by changes in landscape level vegetation were also addressed. The report indicates that in terms of potential changes to the biome classification of Canada's national forests, more northern biomes are projected to decrease. These northern biomes include the tundra, taiga and boreal conifer forests. 56 refs., 8 tabs., 6 figs.

Short-term responses of wetland vegetation after liming of an Adirondack watershed

Energy Technology Data Exchange (ETDEWEB)

Mackun, I.R.; Leopold, D.J.; Raynal, D.J. (State Univ. of New York, Syracuse, NY (United States))

1994-08-01

Watershed liming has been suggested as a long-term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition. However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO[sub 3]) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west-central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0-m[sup 2] plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small-statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

The challenges of long-term ecological research in springs in the northern and southern Alps: indicator groups, habitat diversity, and medium-term change

Directory of Open Access Journals (Sweden)

Sofia WIEDENBRUG

2011-09-01

Full Text Available After extensive exploratory investigations into crenic habitats at the beginning of the 1990s, a number of springs were selected and long-term ecological research programmes independently initiated in the Berchtesgaden National Park (north-eastern Alps, Bavaria and the Adamello-Brenta Nature Park (south-eastern Alps, Trentino. Following more than a decade of standardized work, this paper presents a selection of results from both sides of the Alps, with a focus on zoobenthos in Bavaria and on pro- and eukaryotic algae in Trentino. In order to test the assumption that permanent springs are particularly suitable habitats for long-term ecological research, the following topics are addressed: (1 taxonomic diversity and relationships between diversity and spring typology; (2 transverse gradients in crenic habitats, hygrophilous terrestrial invertebrates and xerotolerant algae; (3 possibilities of documenting changes in species composition over decadal time scales ("medium-term" based on emergence traps, benthos, and benthic algae. The data obtained show that: (1 crenic habitats support particularly high biological diversity (but a thorough documentation of insect diversity is impossible without emergence studies; (2 helocrenes are the most species-rich habitats, for both invertebrates and diatoms; (3 dynamic (unstable and occasionally-impacted springs show identifiable signs of medium-term change, whilst particularly complex and stable crenic habitats seem to be controlled by internal processes. Our results suggest that: (1 the meiofauna is likely to react directly to environmental change, while emergers and the hygrophilous terrestrial fauna are indirectly affected, and (2 diatoms react both to direct effects of environmental change, e.g. discharge and hydrochemistry, and to indirect effects on the surroundings of the spring. Based on our results, long-term research strategies are discussed. For long-term studies, we propose a focus on meiofauna and

The effects of short- and long-term air pollutants on plant phenology and leaf characteristics

International Nuclear Information System (INIS)

Jochner, Susanne; Markevych, Iana; Beck, Isabelle; Traidl-Hoffmann, Claudia

2015-01-01

Pollution adversely affects vegetation; however, its impact on phenology and leaf morphology is not satisfactorily understood yet. We analyzed associations between pollutants and phenological data of birch, hazel and horse chestnut in Munich (2010) along with the suitability of leaf morphological parameters of birch for monitoring air pollution using two datasets: cumulated atmospheric concentrations of nitrogen dioxide and ozone derived from passive sampling (short-term exposure) and pollutant information derived from Land Use Regression models (long-term exposure). Partial correlations and stepwise regressions revealed that increased ozone (birch, horse chestnut), NO_2, NO_x and PM levels (hazel) were significantly related to delays in phenology. Correlations were especially high when rural sites were excluded suggesting a better estimation of long-term within-city pollution. In situ measurements of foliar characteristics of birch were not suitable for bio-monitoring pollution. Inconsistencies between long- and short-term exposure effects suggest some caution when interpreting short-term data collected within field studies. - Highlights: • We present results of a field survey examining pollution effects on vegetation. • Particularly ozone was significantly associated with delays in spring phenology. • Leaf morphology of birch was found to be inadequate for bio-monitoring pollution. • Inconsistencies between long-/short-term exposure effects suggest caution. - Pollutants were significantly associated with delays in spring phenology. However, inconsistencies between long- and short-term exposure effects suggest some caution when interpreting results.

Long-term agricultural experiments inform the development of climate-smart agricultural practices

Directory of Open Access Journals (Sweden)

Kristina Wolf

2017-09-01

Full Text Available California's Mediterranean agro-ecosystems are a major source of U.S. fruits and vegetables, and vulnerable to future extremes of precipitation and temperature brought on by climate change, including increased drought and flooding, and more intense and longer heat waves. To develop resilience to these threats, strategies are necessary for climate-smart management of soil and water. Long-term, large-scale, replicated ecological experiments provide unique testbeds for studying such questions. At the UC Davis Russell Ranch Sustainable Agriculture Facility (RRSAF, the 100-year Century Experiment, initiated in 1992, is investigating the effects of multiple farming practices in a farm-scale replicated study of 10 row crop cropping systems. It includes different fertility management systems: organic, conventional and hybrid (conventional plus winter cover crop systems; different crops: wheat, tomatoes, corn, alfalfa, cover crops and grasslands; and different irrigation systems: rainfed, flood irrigated and drip irrigated. We briefly describe and report on a selection of long-term experiments conducted at RRSAF investigating soil management and irrigation practices, which are an important focus for developing climate-smart strategies in Mediterranean systems. For example, long-term monitoring of soil carbon content revealed that most crop systems have experienced a small increase in soil carbon since 1993, and increases in organically managed plots were substantially higher. As RRSAF continues to build upon this rich dataset from one of a very few long-term row crop experiments in Mediterranean ecosystems, it provides a testbed for identifying climate-smart solutions for these agronomically important ecosystems.

Long-term enhanced winter soil frost alters growing season CO2 fluxes through its impact on vegetation development in a boreal peatland.

Science.gov (United States)

Zhao, Junbin; Peichl, Matthias; Nilsson, Mats B

2017-08-01

At high latitudes, winter climate change alters snow cover and, consequently, may cause a sustained change in soil frost dynamics. Altered winter soil conditions could influence the ecosystem exchange of carbon dioxide (CO 2 ) and, in turn, provide feedbacks to ongoing climate change. To investigate the mechanisms that modify the peatland CO 2 exchange in response to altered winter soil frost, we conducted a snow exclusion experiment to enhance winter soil frost and to evaluate its short-term (1-3 years) and long-term (11 years) effects on CO 2 fluxes during subsequent growing seasons in a boreal peatland. In the first 3 years after initiating the treatment, no significant effects were observed on either gross primary production (GPP) or ecosystem respiration (ER). However, after 11 years, the temperature sensitivity of ER was reduced in the treatment plots relative to the control, resulting in an overall lower ER in the former. Furthermore, early growing season GPP was also lower in the treatment plots than in the controls during periods with photosynthetic photon flux density (PPFD) ≥800 μmol m -2  s -1 , corresponding to lower sedge leaf biomass in the treatment plots during the same period. During the peak growing season, a higher GPP was observed in the treatment plots under the low light condition (i.e. PPFD 400 μmol m -2  s -1 ) compared to the control. As Sphagnum moss maximizes photosynthesis at low light levels, this GPP difference between the plots may have been due to greater moss photosynthesis, as indicated by greater moss biomass production, in the treatment plots relative to the controls. Our study highlights the different responses to enhanced winter soil frost among plant functional types which regulate CO 2 fluxes, suggesting that winter climate change could considerably alter the growing season CO 2 exchange in boreal peatlands through its effect on vegetation development. © 2017 John Wiley & Sons Ltd.

Locating Changes in Land Use from Long Term Remote Sensing Data in Morocco

Science.gov (United States)

We present a method that allows mapping changes in vegetation cover over large areas quickly and inexpensively, thus providing policy makers with the capability to locate and assess areas undergoing environmental change, and improving their ability to positively respond or adapt ...

Monitoring the Long-Term Performance of Engineered Containment Systems: Role of Ecological Processes

International Nuclear Information System (INIS)

Traynham, B.; Clarke, J.H.; Burger, J.; Waugh, J.

2009-01-01

Engineered covers have been widely used to minimize water infiltration into landfills used by U. S. Department of Energy (DOE) for the disposal of radioactive and hazardous chemical waste. The degradation of engineered covers over time is a complex process that is influenced by site specific characteristics, the structure and dynamics of the indigenous plant community, and the interplay of physical and biological factors at contaminated sites. It is necessary to develop a rigorous method to evaluate long-term performance of covers and other engineered barriers with quantification of risk and uncertainty. Because many of the contaminants of concern are long-lived, this methodology must consider changes in the environmental setting (e.g., precipitation, temperature) and cover components for long time periods (>100 years). Current monitoring approaches focus solely on hydrologic properties of the cover system. Additionally, cover design guidelines, such as those from RCRA, are not performance based and do not consider long-term site-specific influences such as climate, vegetation, and soils. Fundamental ecological processes such as succession are not even factored into current models, yet they directly affect the integrity of landfill covers through biointrusion, erosion, and water balance. Therefore, it is useful to identify ecological parameters and processes most important to performance for prioritization of site characterization and long-term monitoring activities. This investigation into the role of ecological monitoring of isolation containment systems utilizes the software platform GoldSim to identify important parameters and processes for performance verification and monitoring. (authors)

Long-term changes in organic matter of woodland soils cleared for arable cropping in Zimbabwe

NARCIS (Netherlands)

Zingore, S.; Manyame, C.; Nyamugafata, P.; Giller, K.E.

2005-01-01

Subsistence farmers in Africa depend largely on the soil organic matter to sustain crop productivity. Long-term changes in soil organic carbon and nitrogen were measured after woodland clearance for smallholder subsistence farming or for commercial farming. The contents of organic carbon and

The impact of future forest dynamics on climate: interactive effects of changing vegetation and disturbance regimes

Science.gov (United States)

Thom, Dominik; Rammer, Werner; Seidl, Rupert

2018-01-01

Currently, the temperate forest biome cools the earth’s climate and dampens anthropogenic climate change. However, climate change will substantially alter forest dynamics in the future, affecting the climate regulation function of forests. Increasing natural disturbances can reduce carbon uptake and evaporative cooling, but at the same time increase the albedo of a landscape. Simultaneous changes in vegetation composition can mitigate disturbance impacts, but also influence climate regulation directly (e.g., via albedo changes). As a result of a number of interactive drivers (changes in climate, vegetation, and disturbance) and their simultaneous effects on climate-relevant processes (carbon exchange, albedo, latent heat flux) the future climate regulation function of forests remains highly uncertain. Here we address these complex interactions to assess the effect of future forest dynamics on the climate system. Our specific objectives were (1) to investigate the long-term interactions between changing vegetation composition and disturbance regimes under climate change, (2) to quantify the response of climate regulation to changes in forest dynamics, and (3) to identify the main drivers of the future influence of forests on the climate system. We investigated these issues using the individual-based forest landscape and disturbance model (iLand). Simulations were run over 200 yr for Kalkalpen National Park (Austria), assuming different future climate projections, and incorporating dynamically responding wind and bark beetle disturbances. To consistently assess the net effect on climate the simulated responses of carbon exchange, albedo, and latent heat flux were expressed as contributions to radiative forcing. We found that climate change increased disturbances (+27.7% over 200 yr) and specifically bark beetle activity during the 21st century. However, negative feedbacks from a simultaneously changing tree species composition (+28.0% broadleaved species) decreased

The impact of future forest dynamics on climate: interactive effects of changing vegetation and disturbance regimes.

Science.gov (United States)

Thom, Dominik; Rammer, Werner; Seidl, Rupert

2017-11-01

Currently, the temperate forest biome cools the earth's climate and dampens anthropogenic climate change. However, climate change will substantially alter forest dynamics in the future, affecting the climate regulation function of forests. Increasing natural disturbances can reduce carbon uptake and evaporative cooling, but at the same time increase the albedo of a landscape. Simultaneous changes in vegetation composition can mitigate disturbance impacts, but also influence climate regulation directly (e.g., via albedo changes). As a result of a number of interactive drivers (changes in climate, vegetation, and disturbance) and their simultaneous effects on climate-relevant processes (carbon exchange, albedo, latent heat flux) the future climate regulation function of forests remains highly uncertain. Here we address these complex interactions to assess the effect of future forest dynamics on the climate system. Our specific objectives were (1) to investigate the long-term interactions between changing vegetation composition and disturbance regimes under climate change, (2) to quantify the response of climate regulation to changes in forest dynamics, and (3) to identify the main drivers of the future influence of forests on the climate system. We investigated these issues using the individual-based forest landscape and disturbance model (iLand). Simulations were run over 200 yr for Kalkalpen National Park (Austria), assuming different future climate projections, and incorporating dynamically responding wind and bark beetle disturbances. To consistently assess the net effect on climate the simulated responses of carbon exchange, albedo, and latent heat flux were expressed as contributions to radiative forcing. We found that climate change increased disturbances (+27.7% over 200 yr) and specifically bark beetle activity during the 21st century. However, negative feedbacks from a simultaneously changing tree species composition (+28.0% broadleaved species) decreased

The long-term trends (1982-2006) in vegetation greenness of the alpine ecosystem in the Qinghai-Tibetan Plateau

Science.gov (United States)

Zhang, Li; Guo, Huadong; Wang, Cuizhen; Ji, Lei; Li, Jing; Wang, Kun; Dai, Lin

2014-01-01

The increased rate of annual temperature in the Qinghai-Tibetan Plateau exceeded all other areas of the same latitude in recent decades. The influence of the warming climate on the alpine ecosystem of the plateau was distinct. An analysis of alpine vegetation under changes in climatic conditions was conducted in this study. This was done through an examination of vegetation greenness and its relationship with climate variability using the Advanced Very High Resolution Radiometer satellite imagery and climate datasets. Vegetation in the plateau experienced a positive trend in greenness, with 18.0 % of the vegetated areas exhibiting significantly positive trends, which were primarily located in the eastern and southwestern parts of the plateau. In grasslands, 25.8 % of meadows and 14.1 % of steppes exhibited significant upward trends. In contrast, the broadleaf forests experienced a trend of degradation. Temperature, particularly summer temperature, was the primary factor promoting the vegetation growth in the plateau. The wetter and warmer climate in the east contributed to the favorable conditions for vegetation. The alpine meadow was mostly sensitive to temperature, while the steppes were sensitive to both temperature and precipitation. Although a warming climate was expected to be beneficial to vegetation growth in the alpine region, the rising temperature coupled with reduced precipitation in the south did not favor vegetation growth due to low humidity and poor soil moisture conditions.

The response of lake area and vegetation cover variations to climate change over the Qinghai-Tibetan Plateau during the past 30years.

Science.gov (United States)

Zhang, Zengxin; Chang, Juan; Xu, Chong-Yu; Zhou, Yang; Wu, Yanhong; Chen, Xi; Jiang, Shanshan; Duan, Zheng

2018-09-01

Lakes and vegetation are important factors of the Earth's hydrological cycle and can be called an "indicator" of climate change. In this study, long-term changes of lakes' area and vegetation coverage in the Qinghai-Tibetan Plateau (QTP) and their relations to the climate change were analyzed by using Mann-Kendall method during the past 30years. Results showed that: 1) the lakes' area of the QTP increased significantly during the past 30years as a whole, and the increasing rates have been dramatically sped up since the year of 2000. Among them, the area of Ayakekumu Lake has the fastest growing rate of 51.35%, which increased from 618km 2 in the 1980s to 983km 2 in the 2010s; 2) overall, the Normalized Difference Vegetation Index (NDVI) increased in the QTP during the past 30years. Above 79% of the area in the QTP showed increasing trend of NDVI before the year of 2000; 3) the air temperature increased significantly, the precipitation increased slightly, and the pan evaporation decreased significantly during the past 30years. The lake area and vegetation coverage changes might be related to the climate change. The shifts in the temporal climate trend occurred around the year 2000 had led the lake area and vegetation coverage increasing. This study is of importance in further understanding the environmental changes under global warming over the QTP. Copyright © 2018 Elsevier B.V. All rights reserved.

Coding early naturalists' accounts into long-term fish community changes in the Adriatic Sea (1800-2000.

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Tomaso Fortibuoni

Full Text Available The understanding of fish communities' changes over the past centuries has important implications for conservation policy and marine resource management. However, reconstructing these changes is difficult because information on marine communities before the second half of the 20(th century is, in most cases, anecdotal and merely qualitative. Therefore, historical qualitative records and modern quantitative data are not directly comparable, and their integration for long-term analyses is not straightforward. We developed a methodology that allows the coding of qualitative information provided by early naturalists into semi-quantitative information through an intercalibration with landing proportions. This approach allowed us to reconstruct and quantitatively analyze a 200-year-long time series of fish community structure indicators in the Northern Adriatic Sea (Mediterranean Sea. Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species. This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources. To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

Quantification and Mitigation of Long-Term Impacts of Urbanization and Climate Change in the Tropical Coastal City of San Juan, Puerto Rico

Science.gov (United States)

Comarazamy, Daniel; Gonzalez, Jorge E.; Luvall, Jeffrey C.

2014-01-01

Urbanization, along with other cases of land cover and land use changes, has significant climate impacts in tropical regions with the added complexity of occurring within the context of global warming. The individual and combined effects of these two factors on the surface energy balance of a tropical city are investigated by use of an integrated atmospheric modeling approach, taking the San Juan Metropolitan Area (SJMA), Puerto Rico as the test case. To achieve this goal, an ensemble of climate and weather simulations is performed, with the climate scenarios combining urban development and sprawl with regional climate change over the past 50 years, and the short-term simulations designed to test the sensitivity to different urban vegetation configurations as mitigating alternatives. As indicator of change, we use the thermal response number (TRN), which is a measure of the sensible heating to the thermal storage of a surface or region, and the Bowen ratio, which is defined as the ratio of sensible to latent heat fluxes. The TRN of the area occupied by the SJMA has decreased as a consequence of replacing the low land coastal plain vegetation with man made materials, indicating that it takes less energy to raise the surface temperature of the urban area, whereas the TRN of forested regions has remained virtually unchanged. The global warming signal also has effects on the thermal response of the SJMA, where dryer current conditions generate lower TRN values. Differences due to global warming are more evident in the Bowen ratio pattern, mostly associated with the drier present conditions observed and its effects on sensible and latent heat fluxes. In terms of testing different mitigation strategies, the short-term simulations show that the urban area is more efficient in partitioning surface energy balance terms when green roofs are specified, as opposed to including vegetation inside the urban core.

Accelerated long-term assessment of thermal and chemical stability of bio-based phase change materials

Science.gov (United States)

Thermal energy storage (TES) systems incorporated with phase change materials (PCMs) have potential applications to control energy use by building envelopes. However, it is essential to evaluate long term performance of the PCMs and cost effectiveness prior to full scale implementation. For this rea...

Assessing Forest Carbon Response to Climate Change and Disturbances Using Long-term Hydro-climatic Observations and Simulations

Science.gov (United States)

Trettin, C.; Dai, Z.; Amatya, D. M.

2014-12-01

Long-term climatic and hydrologic observations on the Santee Experimental Forest in the lower coastal plain of South Carolina were used to estimate long-term changes in hydrology and forest carbon dynamics for a pair of first-order watersheds. Over 70 years of climate data indicated that warming in this forest area in the last decades was faster than the global mean; 35+ years of hydrologic records showed that forest ecosystem succession three years following Hurricane Hugo caused a substantial change in the ratio of runoff to precipitation. The change in this relationship between the paired watersheds was attributed to altered evapotranspiration processes caused by greater abundance of pine in the treatment watershed and regeneration of the mixed hardwood-pine forest on the reference watershed. The long-term records and anomalous observations are highly valuable for reliable calibration and validation of hydrological and biogeochemical models capturing the effects of climate variability. We applied the hydrological model MIKESHE that showed that runoff and water table level are sensitive to global warming, and that the sustained warming trends can be expected to decrease stream discharge and lower the mean water table depth. The spatially-explicit biogeochemical model Forest-DNDC, validated using biomass measurements from the watersheds, was used to assess carbon dynamics in response to high resolution hydrologic observation data and simulation results. The simulations showed that the long-term spatiotemporal carbon dynamics, including biomass and fluxes of soil carbon dioxide and methane were highly regulated by disturbance regimes, climatic conditions and water table depth. The utility of linked-modeling framework demonstrated here to assess biogeochemical responses at the watershed scale suggests applications for assessing the consequences of climate change within an urbanizing forested landscape. The approach may also be applicable for validating large

Calcium regulation in long-term changes of neuronal excitability in the hippocampal formation

Energy Technology Data Exchange (ETDEWEB)

Mody, I.

1985-01-01

The regulation of calcium (Ca/sup 2 +/) was examined during long-term changes of neuronal excitability in the mammalian CNS. The preparations under investigation included the kindling model of epilepsy, a genetic form of epilepsy and long-term potentiation (LTP) of neuronal activity. The study also includes a discussion of the possible roles of a neuron-specific calcium-binding protein (CaBP). The findings are summarized as follows: (1) CaBP was found to have an unequal distribution in various cortical areas of the rat with higher levels in ventral structures. (2) The decline in CaBP was correlated to the number of evoked afterdischarges (AD's) during kindling-induced epilepsy. (3) Marked changes in CaBP levels were also found in the brains of the epileptic strain of mice (El). The induction of seizures further decreased the levels of CaBP in the El mice, indicating a possible genetic impairment of neuronal Ca/sup 2 +/ homeostasis in the El strain. (4) The levels of total hippocampal Ca/sup 2 +/ and Zn/sup 2 +/ were measured by atomic absorption spectrophotometry in control and commissural-kindled animals. (5) To measure Ca/sup 2 +/-homeostasis, the kinetic analysis of /sup 45/Ca uptake curves was undertaken in the in vitro hippocampus. (6) The kinetic analysis of /sup 45/Ca uptake curves revealed that Ca/sup 2 +/-regulation of the hippocampus is impaired following amygdala- and commissural kindling. (7). A novel form of long-term potentiation (LTP) of neuronal activity in the CA1 region of the hippocampus is described. The findings raise the possibility that the Ca/sup 2 +/ necessary for induction of LTP may be derived from an intraneuronal storage site.

Long-term energy balance and vegetation water stress monitoring of Mediterranean oak savanna using satellite thermal data

Science.gov (United States)

González-Dugo, Maria P.; Chen, Xuelong; Andreu, Ana; Carpintero, Elisabet; Gómez-Giraldez, Pedro; Su, Z.(Bob)

2017-04-01

Drought is one of the major hazards faced by natural and cropped vegetation in the Mediterranean Sea Basin. Water scarcity is likely to be worsened under the predicted conditions of climate change, which is expected to make this region both warmer and drier. A Holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs. This ecosystem is considered an example of sustainable land use, supporting a large number of species and diversity of habitats and for its importance in rural economy. A similar ecosystem is worldwide distributed in areas with Mediterranean climate (as California or South Africa) and shares structural and functional properties with tropical savannas in Africa, Australia and South America. Remote sensing time series can assist the monitoring of the energy balance components, with special attention to the evapotranspiration and vegetation water stress over these areas. Long-term data analysis may improve our understanding of the functioning of the system, helping to assess drought impacts and leading to reduce the economic and environmental vulnerability of this ecosystem. This work analyzes the evolution the surface energy balance components, mapping the evapotranspiration and moisture stress of holm oak woodlands of Spain and Portugal during the last 15 years (2001-2015). The surface energy balance model (SEBS) has been applied over the Iberian Peninsula on a monthly time scale and 0.05° spatial resolution, using multi-satellite and meteorological forcing data. Modelled energy and water fluxes have been validated using ground measurements of two eddy covariance towers located in oak savanna sites during 3 years, resulting in moderate deviations from observations (10-25 W/m2). The departure of actual ET from the

Long-Term Changes in Pain Sensitivity in an Animal Model of Social Anxiety

Directory of Open Access Journals (Sweden)

Alessandra Berry

2014-07-01

Full Text Available Animal models with an eco-ethological relevance can help in identifying novel and reliable stress-related markers. To this end, 3-month-old C57BL/6J male mice were exposed to social defeat (SD stress for 10 days as this stressor shows good face and predictive validity for several models of human affective disorders including depression, social phobia and post-traumatic stress disorder. Social avoidance and pain threshold were assessed 24 h and 4 weeks after the end of SD stress, while corticosterone was assayed at the beginning and at the end of the stressful procedure (days 1 and 10. SD subjects were characterized by increased corticosterone levels (30 min following stress exposure, increased latency to approach the social target in the short-term as well as increased emotionality in the long-term. Moreover, an increase in nociceptive threshold (stress-induced analgesia was found both in the short-term and 4 weeks after the end of stress. These data indicate that the SD paradigm is able to induce emotional changes associated with a stressful/traumatic event. In addition, they indicate that variations in the nociceptive threshold might represent a physiological marker of both short- and long-term effects of stress.

Change of nuclear administrative system and long-term program for nuclear energy in Japan

International Nuclear Information System (INIS)

Yun, S. W.; Yang, M. H.; Jeong, H. S.

2001-01-01

Japanese new governmental adminstrative system was restructured and became in operation from January 1, 2001 including newly establishment of the Ministry of Cabinet. Accordingly, Japanese nuclear administrative system were also changed significantly, in order to reflect the changing policy environment and response to them more efficiently in the use and development of nuclear energy. Atomic Energy Commission, Nuclear Safety Commission administrated by Science and Technology Agency in the past, were moved to the Ministry of Cabinet, and Integrated Science and Technology Council was also newly established under the Ministry of Cabinet. And Ministry of Economy, Trade and Industry(METI) is in charge of nuclear energy policy and the Ministry of Education, Culture, Sports, Science and Technology(MEXT) is in charge of nuclear academic science consequently. At the same time, the revision work of 'Long-term Program for Research, Development and Utilization of Nuclear of Japan' established in 1994, has been carried out from 1999 in order to set up the long term based national nuclear policy towards the 21st century, and finally the results were open to the public in November 2000. Major changes of nuclear policy of Japan the will be good references in the establishing future national nuclear policy for the use and development of nuclear energy

VEGETATION RESPONSE TO CLIMATE CHANGE IN THE SOUTHERN PART OF QINGHAI-TIBET PLATEAU AT BASINAL SCALE

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X. Liu

2018-04-01

Full Text Available Global climate change has significantly affected vegetation variation in the third-polar region of the world – the Qinghai-Tibet Plateau. As one of the most important indicators of vegetation variation (growth, coverage and tempo-spatial change, the Normalized Difference Vegetation Index (NDVI is widely employed to study the response of vegetation to climate change. However, a long-term series analysis cannot be achieved because a single data source is constrained by time sequence. Therefore, a new framework was presented in this paper to extend the product series of monthly NDVI, taking as an example the Yarlung Zangbo River Basin, one of the most important river basins in the Qinghai-Tibet Plateau. NDVI products were acquired from two public sources: Global Inventory Modeling and Mapping Studies (GIMMS Advanced Very High Resolution Radiometer (AVHRR and Moderate-Resolution Imaging spectroradiometer (MODIS. After having been extended using the new framework, the new time series of NDVI covers a 384 months period (1982–2013, 84 months longer than previous time series of NDVI product, greatly facilitating NDVI related scientific research. In the new framework, the Gauss Filtering Method was employed to filter out noise in the NDVI product. Next, the standard method was introduced to enhance the comparability of the two data sources, and a pixel-based regression method was used to construct NDVI-extending models with one pixel after another. The extended series of NDVI fit well with original AVHRR-NDVI. With the extended time-series, temporal trends and spatial heterogeneity of NDVI in the study area were studied. Principal influencing factors on NDVI were further determined. The monthly NDVI is highly correlated with air temperature and precipitation in terms of climatic change wherein the spatially averaged NDVI slightly increases in the summer and has increased in temperature and decreased in precipitation in the 32 years period. The

Pulmonary function changes in long-term survivors of bone marrow transplantation

International Nuclear Information System (INIS)

Gore, Elizabeth M.; Lawton, Colleen A.; Ash, Robert C.; Lipchik, Randolph J.

1996-01-01

Purpose: This study was undertaken to evaluate long-term pulmonary function changes in patients undergoing bone marrow transplantation (BMT), to assess their clinical significance, and to identify factors influencing these changes. Methods and Materials: Pulmonary function tests (PFT) were evaluated before and after BMT in 111 adult patients undergoing BMT between 1985 and 1991. Forced expiratory volume at 1 s (FEV 1 ), forced vital capacity (FVC), diffusing capacity (DLCO), and total lung capacity (TLC) were evaluated. One hundred and three patients (92.8%) received total body irradiation (TBI) to a total dose of 14 Gy in nine equal fractions. The lung dose was restricted to 1 , FVC, and TLC were lower than pre transplant values (p 1 did not fall significantly in patients without acute or chronic GVHD and recovered earlier than in patients without post transplant pulmonary infection. Recovery of FVC, TLC, and DLCO was also delayed in patients with acute and chronic GVHD and post transplant pulmonary infection. Multiple regression analysis revealed an association between a higher radiation dose to the lungs, and decreased FVC at 2 years (p = 0.01). Progressive obstructive pulmonary disease was not observed. Conclusions: An initial decline in PFTs with subsequent recovery was observed. Factors associated with delayed recovery and incomplete recovery of PFTs were GVHD, post transplant pulmonary infection, and higher radiation dose to the lungs. The conditioning regimen used at Medical College of Wisconsin, including relatively high TBI doses with partial transmission pulmonary shielding, appears to be well tolerated by the lungs in long-term survivors. No progressive decline in PFTs or symptomatic decline in pulmonary function was observed during the time interval studied

Risk factors and long-term changes of non-arteritis anterior ischaemic optic neuropathy

Directory of Open Access Journals (Sweden)

Ying-Xin Cui

2016-01-01

Full Text Available AIM:To investigate the risk factors and long-term changes of non-arteritis anterior ischaemic optic neuropathy(NAION. METHODS:Three hundred and sixty cases of patients with NAION in our hospital from January 2010 to Juny 2015 were used as patients group and another 400 people undergoing health examination were used as control group. The clinical data was collected. Optical coherence tomography(OCTwas performed. RESULTS:There were significant difference on gender, history of diabetes or hypertension, arteriosclerosis history, disc area, cup area, rim area, cup/disc area ratio, horizontal cup-disc ratio, vertical cup-disc ratio, FBG and TG of two groups(PPP>0.05. CONCLUSION:Male, with diabetes, history of hypertension, arteriosclerosis history, disc area, cup area, rim area, cup/disc area ratio, horizontal cup-disc ratio, vertical cup-disc ratio, FBG and TG are independent risk factors of NAION. Long-term damage of RNFL may not aggravate.

Temporal reflectance changes in vegetables

DEFF Research Database (Denmark)

Dissing, Bjørn Skovlund; Clemmensen, Line Katrine Harder; Ersbøll, Bjarne Kjær

2009-01-01

Quality control in the food industry is often performed by measuring various chemical compounds of the food involved. We propose an imaging concept for acquiring high quality multispectral images to evaluate changes of carrots and celeriac over a period of 14 days. Properties originating...... in the surface chemistry of vegetables may be captured in an integrating sphere illumination which enables the creation of detailed surface chemistry maps with a good combination of spectral and spatial resolutions. Prior to multispectral image recording, the vegetables were prefried and frozen at -30Â......°C for four months. During the 14 days of image recording, the vegetables were kept at +5°C in refrigeration. In this period, surface changes and thereby reflectance properties were very subtle. To describe this small variation we employed advanced statistical techniques to search a large featurespace...

The relationship of long term global temperature change and human fertility.

Science.gov (United States)

Fisch, Harry; Andrews, Howard F; Fisch, Karen S; Golden, Robert; Liberson, Gary; Olsson, Carl A

2003-07-01

According to the United Nations, global fertility has declined in the last century as reflected by a decline in birth rates. The earth's surface air temperature has increased considerably and is referred to as global warming. Since changes in temperature are well known to influence fertility we sought to determine if a statistical relationship exists between long-term changes in global air temperatures and birth rates. The most complete and reliable birth rate data in the 20th century was available in 19 industrialized countries. Using bivariate and multiple regression analysis, we compared yearly birth rates from these countries to global air temperatures from 1900 to 1994.A common pattern of change in birth rates was noted for the 19 industrialized countries studied. In general, birth rates declined markedly throughout the century except during the baby boom period of approximately 1940 to 1964. An inverse relationship was found between changes in global temperatures and birth rates in all 19 countries. Controlling for the linear yearly decline in birth rates over time, this relationship remained statistically significant for all the 19 countries in aggregate and in seven countries individually (phuman fertility may have been influenced by change in environmental temperatures.

Thin-plate spline analysis of mandibular shape changes induced by functional appliances in Class II malocclusion : A long-term evaluation.

Science.gov (United States)

Franchi, Lorenzo; Pavoni, Chiara; Faltin, Kurt; Bigliazzi, Renato; Gazzani, Francesca; Cozza, Paola

2016-09-01

The purpose of this work was to evaluate the long-term morphological mandibular changes induced by functional treatment of Class II malocclusion with mandibular retrusion. Forty patients (20 females, 20 males) with Class II malocclusion consecutively treated with either a Bionator or an Activator followed by fixed appliances were compared with a control group of 40 subjects (19 females, 21 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (T1, mean age 9.9 years), at the end of treatment with functional appliances (T2, mean age 12.2 years), and for long-term follow-up (T3, mean age 18.3 years). Mandibular shape changes were analyzed on lateral cephalograms of the subjects in both groups via thin-plate spline (TPS) analysis. Shape differences were statistically analyzed by conducting permutation tests on Goodall F statistics. In the long term, both the treated and control groups exhibited significant longitudinal mandibular shape changes characterized by upward and forward dislocation of point Co associated with a vertical extension in the gonial region and backward dislocation of point B. Functional appliances induced mandible's significant posterior morphogenetic rotation over the short term. The treated and control groups demonstrated similar mandibular shape over the long term.

Simulating the Holocene climate evolution at northern high latitudes using a coupled atmosphere-sea ice-ocean-vegetation model

NARCIS (Netherlands)

Renssen, H.; Goosse, H.; Fichefet, T.; Brovkin, V.; Driesschaert, E.; Wolk, F.

2005-01-01

The response of the climate at high northern latitudes to slowly changing external forcings was studied in a 9,000-year long simulation with the coupled atmosphere-sea ice-ocean-vegetation model ECBilt-CLIO-VECODE. Only long-term changes in insolation and atmospheric CO

Trends in landscape and vegetation change and implications for the Santa Cruz Watershed

Science.gov (United States)

Villarreal, Miguel; Norman, Laura M.; Webb, Robert H.; Turner, Raymond M.

2013-01-01

Monitoring and characterizing the interactive effects of land use and climate on land surface processes is a primary focus of land change science, and of particular concern in arid Wells Distribution in Shallow Groundwater Areas Pumping Trends Increase Streamflow Extent Declines 27 environments where both landscapes and livelihoods can be impacted by short-term climate variability. Using a multi-observational approach to land-change analysis that included landownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. Our study area is the bi-national Santa Cruz Watershed, a topographically complex watershed that straddles the Sonoran Desert and the Madrean Archipelago Ecoregions. In this presentation we focus on historical changes in vegetation and land use in grasslands and riparian areas of the Madrean Ecoregion (San Raphael Valley, Cienega Creek, Sonoita), and compare changes in these areas to changes in the warmer and drier Sonoran Ecoregion. Analysis of historical photography confirms major 20th century vegetation shifts documented in other research: woody plant encroachment, desertification of grasslands, and changing riparian and xeroriparian vegetation occurred in both ecoregions following human settlement. However, vegetation changes over the past decade appear to be more subtle and some of the past trajectories appear to be reversing; most notable are recent mesquite declines in xeroriparian and upland areas, and changes from shrubland to grassland area in the Madrean ecoregion. Land cover changes were temporally variable, reflecting broad climate changes. The most dynamic cover changes occurred during the period from 1989 to 1999, a period with two intense droughts. The degree of vegetation change

Modeling Wettability Variation during Long-Term Water Flooding

Directory of Open Access Journals (Sweden)

Renyi Cao

2015-01-01

Full Text Available Surface property of rock affects oil recovery during water flooding. Oil-wet polar substances adsorbed on the surface of the rock will gradually be desorbed during water flooding, and original reservoir wettability will change towards water-wet, and the change will reduce the residual oil saturation and improve the oil displacement efficiency. However there is a lack of an accurate description of wettability alternation model during long-term water flooding and it will lead to difficulties in history match and unreliable forecasts using reservoir simulators. This paper summarizes the mechanism of wettability variation and characterizes the adsorption of polar substance during long-term water flooding from injecting water or aquifer and relates the residual oil saturation and relative permeability to the polar substance adsorbed on clay and pore volumes of flooding water. A mathematical model is presented to simulate the long-term water flooding and the model is validated with experimental results. The simulation results of long-term water flooding are also discussed.

Barriers and Facilitators to Implementing a Change Initiative in Long-Term Care Using the INTERACT® Quality Improvement Program.

Science.gov (United States)

Tappen, Ruth M; Wolf, David G; Rahemi, Zahra; Engstrom, Gabriella; Rojido, Carolina; Shutes, Jill M; Ouslander, Joseph G

Implementation of major organizational change initiatives presents a challenge for long-term care leadership. Implementation of the INTERACT® (Interventions to Reduce Acute Care Transfers) quality improvement program, designed to improve the management of acute changes in condition and reduce unnecessary emergency department visits and hospitalizations of nursing home residents, serves as an example to illustrate the facilitators and barriers to major change in long-term care. As part of a larger study of the impact of INTERACT® on rates of emergency department visits and hospitalizations, staff of 71 nursing homes were called monthly to follow-up on their progress and discuss successful facilitating strategies and any challenges and barriers they encountered during the yearlong implementation period. Themes related to barriers and facilitators were identified. Six major barriers to implementation were identified: the magnitude and complexity of the change (35%), instability of facility leadership (27%), competing demands (40%), stakeholder resistance (49%), scarce resources (86%), and technical problems (31%). Six facilitating strategies were also reported: organization-wide involvement (68%), leadership support (41%), use of administrative authority (14%), adequate training (66%), persistence and oversight on the part of the champion (73%), and unfolding positive results (14%). Successful introduction of a complex change such as the INTERACT® quality improvement program in a long-term care facility requires attention to the facilitators and barriers identified in this report from those at the frontline.

Long-term climate monitoring by the global climate observing system

International Nuclear Information System (INIS)

Karl, T.R.

1995-12-01

Is the climate warming? Is the hydrologic cycle changing? Is the atmospheric/oceanic circulation changing? Is the climate becoming more variable or extreme? Is radiative forcing of the climate changing? are complex questions not only from the standpoint of a multi-variate problem, but because of the various aspects of spatial and temporal sampling that must be considered on a global scale. The development of a Global Climate Observing System (GCOS) offers the opportunity for scientists to do something about existing observing deficiencies in light of the importance of documenting long-term climate changes that may already be affected by anthropogenic changes of atmospheric composition and land use as well as other naturally occurring changes. As an important step toward improving the present inadequacies, a workshop was held to help define the long-term monitoring requirements minimally needed to address the five questions posed above, with special emphasis on detecting anthropogenic climate change and its potential impact on managed and unmanaged systems The workshop focussed on three broad areas related to long-term climate monitoring: (a) the scientific rationale for the long-term climate products (including their accuracy, resolution, and homogeneity) required from our observing systems as related to climate monitoring and climate change detection and attribution; (b) the status of long-term climate products and the observing systems from which these data are derived; and (c) implementation strategies necessary to fulfill item (a) in light of existing systems. Item (c) was treated more in terms of feasibility rather than as a specific implementation plan. figs., tabs., refs

Long-term energy futures: the critical role of technology

International Nuclear Information System (INIS)

Grubler, A.

1999-01-01

The paper briefly reviews the results of a 5-year study conducted by IIASA jointly with the World Energy Council (WEC) on long term-energy perspectives. After summarizing the study's main findings, the paper addresses the crucial role of technological change in the evolution of long-term energy futures and in responding to key long-term uncertainties in the domains of energy demand growth, economics, as well as environmental protection. Based on most recent empirical and methodological findings, long-term dynamics of technological change portray a number of distinct features that need to be taken account of in technology and energy policy. First, success of innovation efforts and ultimate outcomes of technological are uncertain. Second, new, improved technologies are not a free good, but require continued dedicated efforts. Third, technological knowledge (as resulting from R and D and accumulation of experience, i.e. technological learning) exhibits characteristics of (uncertain) increasing returns. Forth, due to innovation - diffusion lags, technological interdependence, and infrastructure needs (network externalities), rates of change in large-scale energy systems are necessarily slow. This implies acting sooner rather than later as a contigency policy to respond to long-term social, economic and environmental uncertainties, most notably possible climate change. Rather than picking technological 'winners' the results of the IIASA-WEC scenario studies are seen most appropriate to guide technology and R and D portfolio analysis. Nonetheless, robust persistent patterns of technological change invariably occur across all scenarios. Examples of primising groups of technologies are given. The crucial importance of meeting long-energy demand in developing countries, assuring large-scale infrastructure investments, maintaining a strong and diversified R AND D protfolio, as well as to dvise new institutional mechnisms for technology development and diffusion for instance

Increasing children's lunchtime consumption of fruit and vegetables: an evaluation of the Food Dudes programme.

Science.gov (United States)

Upton, Dominic; Upton, Penney; Taylor, Charlotte

2013-06-01

Although previous research has shown that the Food Dudes programme increases children's fruit and vegetable consumption at school, there has been limited evaluation of the extent to which changes are maintained in the long term. Furthermore, despite knowledge that the nutritional content of home-supplied meals is lower than that of school-supplied meals, little consideration has been given to the programme's impact on meals provided from home. The present study therefore assessed the long-term effectiveness of the Food Dudes programme for both school- and home-supplied lunches. Two cohorts of children participated, one receiving the Food Dudes intervention and a matched control group who did not receive any intervention. Consumption of fruit and vegetables was assessed pre-intervention, then at 3 and 12 months post-intervention. Consumption was measured across five consecutive days in each school using weighed intake (school-provided meals) and digital photography (home-provided meals). Fifteen primary schools, six intervention (n 1282) and seven control schools (n 1151). Participants were children aged 4-11 years. A significant increase in the consumption of fruit and vegetables was found at 3 months for children in the intervention schools, but only for those eating school-supplied lunches. However, increases were not maintained at 12 months. The Food Dudes programme has a limited effect in producing even short-term changes in children's fruit and vegetable consumption at lunchtime. Further development work is required to ensure the short- and long-term effectiveness of interventions promoting fruit and vegetable consumption in children such as the Food Dudes programme.

Changes in composition, ecology and structure of high-mountain vegetation: a re-visitation study over 42 years.

Science.gov (United States)

Evangelista, Alberto; Frate, Ludovico; Carranza, Maria Laura; Attorre, Fabio; Pelino, Giovanni; Stanisci, Angela

2016-01-27

High-mountain ecosystems are increasingly threatened by climate change, causing biodiversity loss, habitat degradation and landscape modifications. However, very few detailed studies have focussed on plant biodiversity in the high mountains of the Mediterranean. In this study, we investigated the long-term changes that have occurred in the composition, structure and ecology of high-mountain vegetation in the central Apennines (Majella) over the last 42 years. We performed a re-visitation study, using historical and newly collected vegetation data to explore which ecological and structural features have been the most successful in coping with climatic changes. Vegetation changes were analysed by comparing geo-referenced phytosociological relevés collected in high-mountain habitats (dolines, gentle slopes and ridges) on the Majella massif in 1972 and in 2014. Composition analysis was performed by detrended correspondence analysis, followed by an analysis of similarities for statistical significance assessment and by similarity percentage procedure (SIMPER) for identifying which species indicate temporal changes. Changes in ecological and structural indicators were analysed by a permutational multivariate analysis of variance, followed by a post hoc comparison. Over the last 42 years, clear floristic changes and significant ecological and structural variations occurred. We observed a significant increase in the thermophilic and mesonitrophilic plant species and an increment in the frequencies of hemicryptophytes. This re-visitation study in the Apennines agrees with observations in other alpine ecosystems, providing new insights for a better understanding of the effects of global change on Mediterranean high-mountain biodiversity. The observed changes in floristic composition, the thermophilization process and the shift towards a more nutrient-demanding vegetation are likely attributable to the combined effect of higher temperatures and the increase in soil nutrients

Effects of Cortisol on Short and Long Term Diet and Morphology

DEFF Research Database (Denmark)

Peiman, Kathryn S.; Birnie-Gauvin, Kim; Larsen, Martin Hage

2017-01-01

Glucocorticoids such as cortisol are released during stressful events. However, many of the effects of cortisol on animals in the wild are still poorly documented. We evaluated the effects of artificially elevated cortisol on diet and morphology over the short term (2 weeks) and long term (4 months......) using a wild population of juvenile semi-anadromous brown trout (Salmo trutta) in Denmark. We caught, tagged and manipulated juvenile fish while in their natal freshwater streams in the fall. Manipulations consisted of an exogenous intracoelomic injection of cortisol suspended in vegetable shortening...... using geometric morphometrics. Cortisol affected carbon stable isotope signatures but had minimal effects on nitrogen isotopes and morphology. Irrespective of treatment, carbon and nitrogen stable isotope values increased over time. This study shows that cortisol can have both short and long term...

Extra-auditory responses to long-term intermittent noise stimulation in humans.

Science.gov (United States)

Fruhstorfer, B; Hensel, H

1980-12-01

Respiration, heart rate, cutaneous blood flow, and electroencephalogram (EEG) reactions to long-term intermittent noise exposure were recorded from 13 volunteers (20-29 yr) with normal hearing and vegetative reactivity. They received daily within 1 h 12 noise stimuli (16 s 100 dB (A) white noise) for 10 or 21 days, respectively. Most subjects reported partial subjective adaptation to the noise. Heart rate adapted within a session but did not change considerably during successive days. Vascular responses did not change during one session but diminished mainly during the first 10 days. Noise responses in the EEG remained constant, but a decrease in vigilance occurred during the whole experimental series. Respiration responses were unpredictable and showed no trend within the sessions. It was concluded that certain physiological responses adapt to loud noise but that the time course of adaptation is different. Therefore a general statement about physiological noise adaptation is not possible.

Investing in rangeland restoration in the Arid West, USA: countering the effects of an invasive weed on the long-term fire cycle.

Science.gov (United States)

Epanchin-Niell, Rebecca; Englin, Jeffrey; Nalle, Darek

2009-01-01

In large areas of the arid western United States, much of which are federally managed, fire frequencies and associated management costs are escalating as flammable, invasive cheatgrass (Bromus tectorum) increases its stronghold. Cheatgrass invasion and the subsequent increase in fire frequency result in the loss of native vegetation, less predictable forage availability for livestock and wildlife, and increased costs and risk associated with firefighting. Revegetation following fire on land that is partially invaded by cheatgrass can reduce both the dominance of cheatgrass and its associated high fire rate. Thus restoration can be viewed as an investment in fire-prevention and, if native seed is used, an investment in maintaining native vegetation on the landscape. Here we develop and employ a Markov model of vegetation dynamics for the sagebrush steppe ecosystem to predict vegetation change and management costs under different intensities and types of post-fire revegetation. We use the results to estimate the minimum total cost curves for maintaining native vegetation on the landscape and for preventing cheatgrass dominance. Our results show that across a variety of model parameter possibilities, increased investment in post-fire revegetation reduces long-term fire management costs by more than enough to offset the costs of revegetation. These results support that a policy of intensive post-fire revegetation will reduce long-term management costs for this ecosystem, in addition to providing environmental benefits. This information may help justify costs associated with revegetation and raise the priority of restoration in federal land budgets.

Synapses between parallel fibres and stellate cells express long-term changes in synaptic efficacy in rat cerebellum.

Science.gov (United States)

Rancillac, Armelle; Crépel, Francis

2004-02-01

Various forms of synaptic plasticity underlying motor learning have already been well characterized at cerebellar parallel fibre (PF)-Purkinje cell (PC) synapses. Inhibitory interneurones play an important role in controlling the excitability and synchronization of PCs. We have therefore tested the possibility that excitatory synapses between PFs and stellate cells (SCs) are also able to exhibit long-term changes in synaptic efficacy. In the present study, we show that long-term potentiation (LTP) and long-term depression (LTD) were induced at these synapses by a low frequency stimulation protocol (2 Hz for 60 s) and that pairing this low frequency stimulation protocol with postsynaptic depolarization induced a marked shift of synaptic plasticity in favour of LTP. This LTP was cAMP independent, but required nitric oxide (NO) production from pre- and/or postsynaptic elements, depending on the stimulation or pairing protocol used, respectively. In contrast, LTD was not dependent on NO production but it required activation of postsynaptic group II and possibly of group I metabotropic glutamate receptors. Finally, stimulation of PFs at 8 Hz for 15 s also induced LTP at PF-SC synapses. But in this case, LTP was cAMP dependent, as was also observed at PF-PC synapses for presynaptic LTP induced in the same conditions. Thus, long-term changes in synaptic efficacy can be accomplished by PF-SCs synapses as well as by PF-PC synapses, suggesting that both types of plasticity might co-operate during cerebellar motor learning.

Short- and long-term eating habit modification predicts weight change in overweight, postmenopausal women: results from the WOMAN study.

Science.gov (United States)

Barone Gibbs, Bethany; Kinzel, Laura S; Pettee Gabriel, Kelley; Chang, Yue-Fang; Kuller, Lewis H

2012-09-01

Standard behavioral obesity treatment produces poor long-term results. Focusing on healthy eating behaviors rather than energy intake may be an alternative strategy. In addition, important behaviors might differ for short- vs long-term weight control. Our aim was to describe and compare associations between changes in eating behaviors and weight after 6 and 48 months. We performed secondary analysis of data collected during a randomized weight-loss intervention trial with 48-month follow-up. We studied 481 overweight and obese postmenopausal women enrolled in the Women on the Move through Activity and Nutrition (WOMAN) Study. We measured changes in weight from baseline to 6 and 48 months. Linear regression models were used to examine the associations between 6- and 48-month changes in eating habits assessed by the Conner Diet Habit Survey and changes in weight. Analyses were conducted in the combined study population and stratified by randomization group. At 6 months in the combined population, weight loss was independently associated with decreased desserts (Pstudies should determine whether interventions targeting these behaviors could improve long-term obesity treatment outcomes. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Short-term fluctuations in vegetation and phytoplankton during the Middle Eocene greenhouse climate: a 640-kyr record from the Messel oil shale (Germany)

Science.gov (United States)

Lenz, Olaf K.; Wilde, Volker; Riegel, Walter

2011-11-01

The Palaeogene was the most recent greenhouse period on Earth. Especially for the Late Palaeocene and Early Eocene, several superimposed short-term hyperthermal events have been described, including extremes such as the Palaeocene-Eocene Thermal Maximum. Major faunal and floral turnovers in the marine and terrestrial realms were recorded in association with these events. High-resolution palynological analysis of the early Middle Eocene maar lake sediments at Messel, near Darmstadt, Germany, provides an insight into the dynamics of a climax vegetation during the Middle Eocene greenhouse climate in a time span without significant climatic excursions. Numerical techniques like detrended correspondence analysis and wavelet analysis have been applied to recognize cyclic fluctuations and long-term trends in the vegetation through a time interval of approximately 640 kyr. Based on the numerical zoning of the pollen diagram, three phases in the development of the vegetation may be distinguished. Throughout these phases, the climax vegetation did not change substantially in qualitative composition, but a trend towards noticeably less humid conditions probably in combination with a drop of the water level in the lake may be recognized. A shift in algal population from the freshwater dinoflagellate cyst Messelodinium thielepfeifferae to a dominance of Botryococcus in the uppermost part of the core is interpreted as a response to changes in acidity and nutrient availability within the lake. Time series analyses of pollen assemblages show that variations in the Milankovitch range of eccentricity, obliquity and precession can be distinguished. In addition, fluctuations in the sub-Milankovitch range are indicated. This demonstrates that floral changes during steady depositional conditions in the Middle Eocene of Messel were controlled by orbital forcing.

Long-term skeletal findings in Menkes disease

International Nuclear Information System (INIS)

Amador, Eva; Domene, Ruth; Fuentes, Cristian; Carreno, Juan-Carlos; Enriquez, Goya

2010-01-01

Skeletal findings in infants with Menkes disease, the most characteristic of which are metaphyseal spurs, long-bone fractures and wormian bones, have been widely reported. However, the changes in skeletal features over time are not well known. The long-term findings differ completely from those initially observed and consist of undertubulation and metaphyseal flaring, similar to the findings seen in some types of bone dysplasia. The initial and long-term radiological features in an 8-year-old boy with Menkes disease are illustrated. (orig.)

Modeling long-term changes in forested landscapes and their relation to the Earth's energy balance

Science.gov (United States)

Shugart, H. H.; Emanuel, W. R.; Solomon, A. M.

1984-01-01

The dynamics of the forested parts of the Earth's surface on time scales from decades to centuries are discussed. A set of computer models developed at Oak Ridge National Laboratory and elsewhere are applied as tools. These models simulate a landscape by duplicating the dynamics of growth, death and birth of each tree living on a 0.10 ha element of the landscape. This spatial unit is generally referred to as a gap in the case of the forest models. The models were tested against and applied to a diverse array of forests and appear to provide a reasonable representation for investigating forest-cover dynamics. Because of the climate linkage, one important test is the reconstruction of paleo-landscapes. Detailed reconstructions of changes in vegetation in response to changes in climate are crucial to understanding the association of the Earth's vegetation and climate and the response of the vegetation to climate change.

Long-term forest resilience to climate change indicated by mortality, regeneration, and growth in semiarid southern Siberia.

Science.gov (United States)

Xu, Chongyang; Liu, Hongyan; Anenkhonov, Oleg A; Korolyuk, Andrey Yu; Sandanov, Denis V; Balsanova, Larisa D; Naidanov, Bulat B; Wu, Xiuchen

2017-06-01

Several studies have documented that regional climate warming and the resulting increase in drought stress have triggered increased tree mortality in semiarid forests with unavoidable impacts on regional and global carbon sequestration. Although climate warming is projected to continue into the future, studies examining long-term resilience of semiarid forests against climate change are limited. In this study, long-term forest resilience was defined as the capacity of forest recruitment to compensate for losses from mortality. We observed an obvious change in long-term forest resilience along a local aridity gradient by reconstructing tree growth trend and disturbance history and investigating postdisturbance regeneration in semiarid forests in southern Siberia. In our study, with increased severity of local aridity, forests became vulnerable to drought stress, and regeneration first accelerated and then ceased. Radial growth of trees during 1900-2012 was also relatively stable on the moderately arid site. Furthermore, we found that smaller forest patches always have relatively weaker resilience under the same climatic conditions. Our results imply a relatively higher resilience in arid timberline forest patches than in continuous forests; however, further climate warming and increased drought could possibly cause the disappearance of small forest patches around the arid tree line. This study sheds light on climate change adaptation and provides insight into managing vulnerable semiarid forests. © 2016 John Wiley & Sons Ltd.

Compositional Changes in Selected Minimally Processed Vegetables

OpenAIRE

O'Reilly, Emer, (Thesis)

2000-01-01

Compositional, physiological and microbiological changes in selected minimally processed vegetables packaged under a modified atmosphere of 2% oxygen and 5% carbon dioxide were monitored over a ten day storage period at 40 C and 80 C. The analysis targeted specific changes in the nutritional, chemical and physiological make up of the vegetables as well as the changes in the microbial levels. In addition the changes in the gas atmospheres within the packs were monitored. It has been widely acc...

Effects on the function of Arctic ecosystems in the short- and long-term perspectives.

Science.gov (United States)

Callaghan, Terry V; Björn, Lars Olof; Chernov, Yuri; Chapin, Terry; Christensen, Torben R; Huntley, Brian; Ims, Rolf A; Johansson, Margareta; Jolly, Dyanna; Jonasson, Sven; Matveyeva, Nadya; Panikov, Nicolai; Oechel, Walter; Shaver, Gus

2004-11-01

Historically, the function of Arctic ecosystems in terms of cycles of nutrients and carbon has led to low levels of primary production and exchanges of energy, water and greenhouse gases have led to low local and regional cooling. Sequestration of carbon from atmospheric CO2, in extensive, cold organic soils and the high albedo from low, snow-covered vegetation have had impacts on regional climate. However, many aspects of the functioning of Arctic ecosystems are sensitive to changes in climate and its impacts on biodiversity. The current Arctic climate results in slow rates of organic matter decomposition. Arctic ecosystems therefore tend to accumulate organic matter and elements despite low inputs. As a result, soil-available elements like nitrogen and phosphorus are key limitations to increases in carbon fixation and further biomass and organic matter accumulation. Climate warming is expected to increase carbon and element turnover, particularly in soils, which may lead to initial losses of elements but eventual, slow recovery. Individual species and species diversity have clear impacts on element inputs and retention in Arctic ecosystems. Effects of increased CO2 and UV-B on whole ecosystems, on the other hand, are likely to be small although effects on plant tissue chemisty, decomposition and nitrogen fixation may become important in the long-term. Cycling of carbon in trace gas form is mainly as CO2 and CH4. Most carbon loss is in the form of CO2, produced by both plants and soil biota. Carbon emissions as methane from wet and moist tundra ecosystems are about 5% of emissions as CO2 and are responsive to warming in the absence of any other changes. Winter processes and vegetation type also affect CH4 emissions as well as exchanges of energy between biosphere and atmosphere. Arctic ecosystems exhibit the largest seasonal changes in energy exchange of any terrestrial ecosystem because of the large changes in albedo from late winter, when snow reflects most

Short- and long-term eating habit modification predict weight change in overweight, post-menopausal women: results from the WOMAN Study

Science.gov (United States)

Gibbs, Bethany Barone; Kinzel, Laura S.; Gabriel, Kelley Pettee; Chang, Yue-fang; Kuller, Lewis H.

2012-01-01

Background Standard behavioral obesity treatment produces poor long-term results. Focusing on healthy eating behaviors, rather than caloric intake, may be an alternative strategy. Furthermore, important behaviors might differ for short- vs. long-term weight control. Objective To describe and compare associations between changes in eating behaviors and weight after 6 and 48 months Design Secondary analysis of data collected during a randomized weight loss intervention trial with 48-month follow-up Participants 465 overweight and obese postmenopausal women enrolled in the Women on the Move through Activity and Nutrition (WOMAN) Study Main outcome measures Changes in weight from baseline to 6 and 48 months. Statistical analyses performed Linear regression models examined the associations between 6- and 48-month changes in eating habits assessed by the Conner Diet Habit Survey and changes in weight. Analyses were conducted in the combined study population and stratified by randomization group. Results At 6 months in the combined population, weight loss was independently associated with decreased desserts (pstudies should determine whether interventions targeting these behaviors could improve long-term obesity treatment outcomes. PMID:22939439

Long-term Satellite NDVI Data Sets: Evaluating Their Ability to Detect Ecosystem Functional Changes in South America.

Science.gov (United States)

Baldi, Germán; Nosetto, Marcelo D; Aragón, Roxana; Aversa, Fernando; Paruelo, José M; Jobbágy, Esteban G

2008-09-03

In the last decades, South American ecosystems underwent important functional modifications due to climate alterations and direct human intervention on land use and land cover. Among remotely sensed data sets, NOAA-AVHRR "Normalized Difference Vegetation Index" (NDVI) represents one of the most powerful tools to evaluate these changes thanks to their extended temporal coverage. In this paper we explored the possibilities and limitations of three commonly used NOAA-AVHRR NDVI series (PAL, GIMMS and FASIR) to detect ecosystem functional changes in the South American continent. We performed pixel-based linear regressions for four NDVI variables (average annual, maximum annual, minimum annual and intra-annual coefficient of variation) for the 1982-1999 period and (1) analyzed the convergences and divergences of significant multi-annual trends identified across all series, (2) explored the degree of aggregation of the trends using the O-ring statistic, and (3) evaluated observed trends using independent information on ecosystem functional changes in five focal regions. Several differences arose in terms of the patterns of change (the sign, localization and total number of pixels with changes). FASIR presented the highest proportion of changing pixels (32.7%) and GIMMS the lowest (16.2%). PAL and FASIR data sets showed the highest agreement, with a convergence of detected trends on 71.2% of the pixels. Even though positive and negative changes showed substantial spatial aggregation, important differences in the scale of aggregation emerged among the series, with GIMMS showing the smaller scale (≤11 pixels). The independent evaluations suggest higher accuracy in the detection of ecosystem changes among PAL and FASIR series than with GIMMS, as they detected trends that match expected shifts. In fact, this last series eliminated most of the long term patterns over the continent. For example, in the "Eastern Paraguay" and "Uruguay River margins" focal regions, the

Long term mineralogical changes in salt formations due to water and brine interactions

International Nuclear Information System (INIS)

Herbert, H.J.; Brewitz, W.

1996-01-01

Four very common long term mineralogical changes in salt formations are discussed in the view of the safety considerations for underground repositories. Two of these processes, the 'Hartsalz' and 'Carnallite' dissolution were studied in two scale in situ experiments. The results are presented and compared with the results of the geochemical modelling with the computer code EQ3/6. Furthermore the reactions leading to the formation of the gypsum cap rock on the top of the Zechstein salt formations and to the polyhalitization of anhydrite are discussed. Geological field observations and mineral assemblages agree well with the results of the geochemical modelling employing the Pitzer formalism along with the Harvie, Moller and Weare database. We conclude that once the mechanisms of the chemical reactions are well understood it becomes possible to evaluate realistically whether such processes, when encountered in the repository, are still active or whether they are finished. It also becomes possible to estimate the volume changes associated with the reactions and thus the impact of these reactions on the integrity and the geomechanical stability of the salt formation. The intimate knowledge of the reaction mechanisms of the short and long term changes in the mineralogical assemblages and the associated brine chemistry is a first prerequisite for the correct evaluation of the origin of brines. Thus, it is essential for the correct assessment of the hazards which brine inflows may pose for the safety of a repository in salt formations. (authors). 8 refs., 14 figs., 8 tabs

Variability and climate change trend in vegetation phenology of recent decades in the Greater Khingan Mountain area, Northeastern China

Directory of Open Access Journals (Sweden)

Huan Tang

2015-09-01

Full Text Available Vegetation phenology has been used in studies as an indicator of an ecosystem’s responses to climate change. Satellite remote sensing techniques can capture changes in vegetation greenness, which can be used to estimate vegetation phenology. In this study, a long-term vegetation phenology study of the Greater Khingan Mountain area in Northeastern China was performed by using the Global Inventory Modeling and Mapping Studies (GIMMS normalized difference vegetation index version 3 (NDVI3g dataset from the years 1982–2012. After reconstructing the NDVI time series, the start date of the growing season (SOS, the end date of the growing season (EOS and the length of the growing season (LOS were extracted using a dynamic threshold method. The response of the variation in phenology with climatic factors was also analyzed. The results showed that the phenology in the study area changed significantly in the three decades between 1982 and 2012, including a 12.1-day increase in the entire region’s average LOS, a 3.3-day advance in the SOS and an 8.8-day delay in the EOS. However, differences existed between the steppe, forest and agricultural regions, with the LOSs of the steppe region, forest region and agricultural region increasing by 4.40 days, 10.42 days and 1.71 days, respectively, and a later EOS seemed to more strongly affect the extension of the growing season. Additionally, temperature and precipitation were closely correlated with the phenology variations. This study provides a useful understanding of the recent change in phenology and its variability in this high-latitude study area, and this study also details the responses of several ecosystems to climate change.

Long-term genetic monitoring of a riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae]: Direct anthropogenic impact versus climate change effects.

Science.gov (United States)

Herzog, Rebecca; Hadrys, Heike

2017-01-01

Modern conservationists call for long term genetic monitoring datasets to evaluate and understand the impact of human activities on natural ecosystems and species on a global but also local scale. However, long-term monitoring datasets are still rare but in high demand to correctly identify, evaluate and respond to environmental changes. In the presented study, a population of the riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae), was monitored over a time period from 1989 to 2013. Study site was an artificial irrigation ditch in one of the last European stone steppes and "nature heritage", the Crau in Southern France. This artificial riverine habitat has an unusual high diversity of odonate species, prominent indicators for evaluating freshwater habitats. A clearing of the canal and destruction of the bank vegetation in 1996 was assumed to have great negative impact on the odonate larval and adult populations. Two mitochondrial markers (CO1 & ND1) and a panel of nuclear microsatellite loci were used to assess the genetic diversity. Over time they revealed a dramatic decline in diversity parameters between the years 2004 and 2007, however not between 1996 and 1997. From 2007 onwards the population shows a stabilizing trend but has not reached the amount of genetic variation found at the beginning of this survey. This decline cannot be referred to the clearing of the canal or any other direct anthropogenic impact. Instead, it is most likely that the populations' decay was due to by extreme weather conditions during the specific years. A severe drought was recorded for the summer months of these years, leading to reduced water levels in the canal causing also other water parameters to change, and therefore impacting temperature sensitive riverine habitat specialists like the O. coerulescens in a significant way. The data provide important insights into population genetic dynamics and metrics not always congruent with traditional monitoring data (e

Using endmembers in AVIRIS images to estimate changes in vegetative biomass

Science.gov (United States)

Smith, Milton O.; Adams, John B.; Ustin, Susan L.; Roberts, Dar A.

1992-01-01

Field techniques for estimating vegetative biomass are labor intensive, and rarely are used to monitor changes in biomass over time. Remote-sensing offers an attractive alternative to field measurements; however, because there is no simple correspondence between encoded radiance in multispectral images and biomass, it is not possible to measure vegetative biomass directly from AVIRIS images. Ways to estimate vegetative biomass by identifying community types and then applying biomass scalars derived from field measurements are investigated. Field measurements of community-scale vegetative biomass can be made, at least for local areas, but it is not always possible to identify vegetation communities unambiguously using remote measurements and conventional image-processing techniques. Furthermore, even when communities are well characterized in a single image, it typically is difficult to assess the extent and nature of changes in a time series of images, owing to uncertainties introduced by variations in illumination geometry, atmospheric attenuation, and instrumental responses. Our objective is to develop an improved method based on spectral mixture analysis to characterize and identify vegetative communities, that can be applied to multi-temporal AVIRIS and other types of images. In previous studies, multi-temporal data sets (AVIRIS and TM) of Owens Valley, CA were analyzed and vegetation communities were defined in terms of fractions of reference (laboratory and field) endmember spectra. An advantage of converting an image to fractions of reference endmembers is that, although fractions in a given pixel may vary from image to image in a time series, the endmembers themselves typically are constant, thus providing a consistent frame of reference.

Institutionalization and Organizational Long-term Success

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Denise L. Fleck

2007-05-01

Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization’s relations with the environment, clearly contributing to environmental institutionalization.

Automatic Threshold Determination for a Local Approach of Change Detection in Long-Term Signal Recordings

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David Hewson

2007-01-01

Full Text Available CUSUM (cumulative sum is a well-known method that can be used to detect changes in a signal when the parameters of this signal are known. This paper presents an adaptation of the CUSUM-based change detection algorithms to long-term signal recordings where the various hypotheses contained in the signal are unknown. The starting point of the work was the dynamic cumulative sum (DCS algorithm, previously developed for application to long-term electromyography (EMG recordings. DCS has been improved in two ways. The first was a new procedure to estimate the distribution parameters to ensure the respect of the detectability property. The second was the definition of two separate, automatically determined thresholds. One of them (lower threshold acted to stop the estimation process, the other one (upper threshold was applied to the detection function. The automatic determination of the thresholds was based on the Kullback-Leibler distance which gives information about the distance between the detected segments (events. Tests on simulated data demonstrated the efficiency of these improvements of the DCS algorithm.

Long-Term Soil Experiments: A Key to Managing Earth's Rapidly Changing Critical Zones

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Richter, D., Jr.

2014-12-01

In a few decades, managers of Earth's Critical Zones (biota, humans, land, and water) will be challenged to double food and fiber production and diminish adverse effects of management on the wider environment. To meet these challenges, an array of scientific approaches is being used to increase understanding of Critical Zone functioning and evolution, and one amongst these approaches needs to be long-term soil field studies to move us beyond black boxing the belowground Critical Zone, i.e., to further understanding of processes driving changes in the soil environment. Long-term soil experiments (LTSEs) provide direct observations of soil change and functioning across time scales of decades, data critical for biological, biogeochemical, and environmental assessments of sustainability; for predictions of soil fertility, productivity, and soil-environment interactions; and for developing models at a wide range of temporal and spatial scales. Unfortunately, LTSEs globally are not in a good state, and they take years to mature, are vulnerable to loss, and even today remain to be fully inventoried. Of the 250 LTSEs in a web-based network, results demonstrate that soils and belowground Critical Zones are highly dynamic and responsive to human management. The objective of this study is to review the contemporary state of LTSEs and consider how they contribute to three open questions: (1) can soils sustain a doubling of food production in the coming decades without further impinging on the wider environment, (2) how do soils interact with the global C cycle, and (3) how can soil management establish greater control over nutrient cycling. While LTSEs produce significant data and perspectives for all three questions, there is on-going need and opportunity for reviews of the long-term soil-research base, for establishment of an efficiently run network of LTSEs aimed at sustainability and improving management control over C and nutrient cycling, and for research teams that

Long-term (1993-2013) changes in macrozooplankton off the Western Antarctic Peninsula

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Steinberg, Deborah K.; Ruck, Kate E.; Gleiber, Miram R.; Garzio, Lori M.; Cope, Joseph S.; Bernard, Kim S.; Stammerjohn, Sharon E.; Schofield, Oscar M. E.; Quetin, Langdon B.; Ross, Robin M.

2015-07-01

The Western Antarctic Peninsula (WAP) is one of the most rapidly warming regions on Earth, and where a high apex predator biomass is supported in large part by macrozooplankton. We examined trends in summer (January-February) abundance of major taxa of macrozooplankton along the WAP over two decades (1993-2013) and their relationship with environmental parameters (sea ice, atmospheric climate indices, sea surface temperature, and phytoplankton biomass and productivity). Macrozooplankton were collected from the top 120 m of the water column in a mid-Peninsula study region divided into latitudinal (North, South, and Far South) and cross-shelf (coastal, shelf, slope) sub-regions. Trends for krill species included a 5-year cycle in abundance peaks (positive anomalies) for Euphausia superba, but no directional long-term trend, and an increase in Thysanoessa macrura in the North; variability in both species was strongly influenced by primary production 2-years prior. E. crystallorophias abundance was best explained by the Southern Annular Mode (SAM) and Multivariate El Niño Southern Oscillation Index (MEI), and was more abundant in higher ice conditions. The salp Salpa thompsoni and thecosome pteropod Limacina helicina cycled between negative and positive anomalies in the North, but showed increasing positive anomalies in the South over time. Variation in salp and pteropod abundance was best explained by SAM and the MEI, respectively, and both species were more abundant in lower ice conditions. There was a long-term increase in some carnivorous gelatinous zooplankton (polychaete worm Tomopteris spp.) and amphipods. Abundance of Pseudosagitta spp. chaetognaths was closely related to SAM, with higher abundance tied to lower ice conditions. Long-term changes and sub-decadal cycles of WAP macrozooplankton community composition may affect energy transfer to higher trophic levels, and alter biogeochemical cycling in this seasonally productive and sensitive polar ecosystem.

The uranium industry: long-term planning for short-term competition

International Nuclear Information System (INIS)

Vottero, X.; Georges Capus, G.

2001-01-01

Long term planning for short term competition Today, uranium producers face new challenges in terms of both production (new regulatory, environmental and social constraints) and market conditions (new sources of uranium supply, very low prices and tough competition). In such a context, long-term planning is not just a prerequisite to survive in the nuclear fuel cycle industry. In fact, it also contributes to sustaining nuclear electricity generation facing fierce competition from other energy sources in increasingly deregulated markets. Firstly, the risk of investing in new mining projects in western countries is growing because, on the one hand, of very erratic market conditions and, on the other hand, of increasingly lengthy, complex and unpredictable regulatory conditions. Secondly, the supply of other sources of uranium (uranium derived from nuclear weapons, uranium produced in CIS countries, ...) involve other risks, mainly related to politics and commercial restrictions. Consequently, competitive uranium supply requires not only technical competence but also financial strength and good marketing capabilities in order to anticipate long-term market trends, in terms of both demand and supply. It also requires taking into account new parameters such as politics, environment, regulations, etc. Today, a supplier dedicated to the sustainable production of nuclear electricity must manage a broad range of long-term risks inherent to the procurement of uranium. Taking into account all these parameters in a context of short-term, fast-changing market is a great challenge for the future generation. World Uranium Civilian Supply and Demand. (authors)

Global vegetation change predicted by the modified Budyko model

Energy Technology Data Exchange (ETDEWEB)

Monserud, R.A.; Tchebakova, N.M.; Leemans, R. (US Department of Agriculture, Moscow, ID (United States). Intermountain Research Station, Forest Service)

1993-09-01

A modified Budyko global vegetation model is used to predict changes in global vegetation patterns resulting from climate change (CO[sub 2] doubling). Vegetation patterns are predicted using a model based on a dryness index and potential evaporation determined by solving radiation balance equations. Climate change scenarios are derived from predictions from four General Circulation Models (GCM's) of the atmosphere (GFDL, GISS, OSU, and UKMO). All four GCM scenarios show similar trends in vegetation shifts and in areas that remain stable, although the UKMO scenario predicts greater warming than the others. Climate change maps produced by all four GCM scenarios show good agreement with the current climate vegetation map for the globe as a whole, although over half of the vegetation classes show only poor to fair agreement. The most stable areas are Desert and Ice/Polar Desert. Because most of the predicted warming is concentrated in the Boreal and Temperate zones, vegetation there is predicted to undergo the greatest change. Most vegetation classes in the Subtropics and Tropics are predicted to expand. Any shift in the Tropics favouring either Forest over Savanna, or vice versa, will be determined by the magnitude of the increased precipitation accompanying global warming. Although the model predicts equilibrium conditions to which many plant species cannot adjust (through migration or microevolution) in the 50-100 y needed for CO[sub 2] doubling, it is not clear if projected global warming will result in drastic or benign vegetation change. 72 refs., 3 figs., 3 tabs.

Long-term maxillomandibular skeletal and dental changes in children with cleft lip and palate after maxillary distraction.

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Harada, Kiyoshi; Sato, Masaru; Omura, Ken

2006-09-01

Long-term skeletal and dental changes were examined in 8 children with cleft lip and palate who underwent maxillary distraction to allow the maxilla to catch up to their mandibular growth at the treatment point. Changes in the overjet (OJ), overbite (OB), and positions of the anterior nasal spine (ANS), upper incisors (U1), pogonion (Pog), and lower incisors (L1) were measured on preoperative to 36 months postoperative lateral-cephalograms. In most of the children, the long-term changes after the maxillary distraction resulted in an inferior growth of the maxilla and anteroinferior growth of the mandible. This seems to suggest that maxillary distraction performed during childhood needs considerable overcorrection. However, if the maxilla is distracted to an adult position during childhood, the masticatory functions of the children will markedly deteriorate until their jaws grow. Therefore, we believe that one goal of maxillary distraction during childhood can be to allow the maxilla to catch up to the mandibular growth of the children at the treatment point.

Space ventures and society long-term perspectives

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Brown, W. M.

1985-01-01

A futuristic evaluation of mankind's potential long term future in space is presented. Progress in space will not be inhibited by shortages of the Earth's physical resources, since long term economic growth will be focused on ways to constrain industrial productivity by changing social values, management styles, or government competence. Future technological progress is likely to accelerate with an emphasis on international cooperation, making possible such large joint projects as lunar colonies or space stations on Mars. The long term future in space looks exceedingly bright even in relatively pessimistic scenarios. The principal driving forces will be technological progress, commercial and public-oriented satellites, space industrialization, space travel, and eventually space colonization.

Mapping long-term wetland response to climate

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Zhou, Q.; Gallant, A.; Rover, J.

2016-12-01

Wetlands provide unique feeding and breeding habitat for numerous waterfowl species. The distribution of wetlands has been considerably changed due to agricultural land conversion and hydrologic modification. Climate change may further impact wetlands through altered moisture regimes. This study characterized long-term variation in wetland conditions by using dense time series from all available Landsat data from 1985 to 2014. We extracted harmonic frequencies from 30 years to two years to delineate the long-term variation in all seven Landsat bands. A cluster analysis and unsupervised classification then enabled us to map different classes of wetland response. We demonstrated the method in the Prairie Pothole Region in North Dakota.

Long-term effects of ionizing radiation

International Nuclear Information System (INIS)

Kaul, Alexander; Burkart, Werner; Grosche, Bernd; Jung, Thomas; Martignoni, Klaus; Stephan, Guenther

1997-01-01

This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

Impact of water-level changes to aquatic vegetation in small oligotrophic lakes

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Egert VANDEL

2016-06-01

Full Text Available This study demonstrates the effect of drastic water-level changes to the aquatic vegetation in three small oligotrophic lakes situated in Kurtna Kame Field in north-eastern Estonia. The area holds around 40 lakes in 30 km2 of which 18 lakes are under protection as Natura Habitat lakes (Natura 2000 network. The area is under a strong human impact as it is surrounded by oil shale mines, sand quarry, peat harvesting field etc. The most severe impact comes from the groundwater intake established in 1972 in the vicinity of three studied lakes. The exploitation of groundwater led to drastic water-level drops. In 1980s the water-level drops were measured to be up to 3 to 4 meters compared to the levels of 1946. Lake Martiska and Lake Kuradijärv were severely affected and only 29% and 45% of lake area respectively and 21% of initial volume remained. Both lakes were described as oligotrophic lakes before severe human impact and held characteristic macrophytes such as Isoëtes lacustris L., Sparganium angustifolium Michx and Lobelia dortmanna L. As the water level declined the lakes lost their rare characteristic species and can now be described more as a meso- or even eutrophic lakes. When the volume of groundwater abstraction decreased in the 1990s the water levels started to recover but did not reach the natural levels of pre-industrialized era. Also the vegetation did not show any signs of recovery. In 2012 the pumping rates increased again causing a new rapid decline in water levels which almost exceed the previous minimum levels. The water-level monitoring alongside with the macrophyte monitoring data gives us a good case study on how the long term abrupt water-level changes can affect the aquatic vegetation

Disrupted Bone Metabolism in Long-Term Bedridden Patients.

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Eimori, Keiko; Endo, Naoto; Uchiyama, Seiji; Takahashi, Yoshinori; Kawashima, Hiroyuki; Watanabe, Kei

2016-01-01

Bedridden patients are at risk of osteoporosis and fractures, although the long-term bone metabolic processes in these patients are poorly understood. Therefore, we aimed to determine how long-term bed confinement affects bone metabolism. This study included 36 patients who had been bedridden from birth due to severe immobility. Bone mineral density and bone metabolism markers were compared to the bedridden period in all study patients. Changes in the bone metabolism markers during a follow-up of 12 years were studied in 17 patients aged bedridden period. During the follow-up, osteocalcin and parathyroid hormone were decreased, and the 25(OH) vitamin D was increased. NTX at baseline was negatively associated with bone mineral density after 12 years. Unique bone metabolic abnormalities were found in patients who had been bedridden for long periods, and these metabolic abnormalities were altered by further bed confinement. Appropriate treatment based on the unique bone metabolic changes may be important in long-term bedridden patients.

Short- and long-term variability of spectral solar UV irradiance at Thessaloniki, Greece: effects of changes in aerosols, total ozone and clouds

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I. Fountoulakis

2016-03-01

Full Text Available In this study, we discuss the short- and the long-term variability of spectral UV irradiance at Thessaloniki, Greece, using a long, quality-controlled data set from two Brewer spectrophotometers. Long-term changes in spectral UV irradiance at 307.5, 324 and 350 nm for the period 1994–2014 are presented for different solar zenith angles and discussed in association with changes in total ozone column (TOC, aerosol optical depth (AOD and cloudiness observed in the same period. Positive changes in annual mean anomalies of UV irradiance, ranging from 2 to 6 % per decade, have been detected both for clear- and all-sky conditions. The changes are generally greater for larger solar zenith angles and for shorter wavelengths. For clear-skies, these changes are, in most cases, statistically significant at the 95 % confidence limit. Decreases in the aerosol load and weakening of the attenuation by clouds lead to increases in UV irradiance in the summer, of 7–9 % per decade for 64° solar zenith angle. The increasing TOC in winter counteracts the effect of decreasing AOD for this particular season, leading to small, statistically insignificant, negative long-term changes in irradiance at 307.5 nm. Annual mean UV irradiance levels are increasing from 1994 to 2006 and remain relatively stable thereafter, possibly due to the combined changes in the amount and optical properties of aerosols. However, no statistically significant corresponding turning point has been detected in the long-term changes of AOD. The absence of signatures of changes in AOD in the short-term variability of irradiance in the UV-A may have been caused by changes in the single scattering albedo of aerosols, which may counteract the effects of changes in AOD on irradiance. The anti-correlation between the year-to-year variability of the irradiance at 307.5 nm and TOC is clear and becomes clearer as the AOD decreases.

The long term agroecosystem research network - shared research strategy

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Jean L. Steiner; Timothy Strickland; Peter J.A. Kleinman; Kris Havstad; Thomas B. Moorman; M.Susan Moran; Phil Hellman; Ray B. Bryant; David Huggins; Greg McCarty

2016-01-01

While current weather patterns and rapidly accelerated changes in technology often focus attention on short-term trends in agriculture, the fundamental demands on modern agriculture to meet society food, feed, fuel and fiber production while providing the foundation for a healthy environment requires long-term perspective. The Long- Term Agroecoystem Research Network...

Vegetation cover and long-term conservation of radioactive waste packages: the case study of the CSM waste disposal facility (Manche District, France).

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Petit-Berghem, Yves; Lemperiere, Guy

2012-03-01

The CSM is the first French waste disposal facility for radioactive waste. Waste material is buried several meters deep and protected by a multi-layer cover, and equipped with a drainage system. On the surface, the plant cover is a grassland vegetation type. A scientific assessment has been carried out by the Géophen laboratory, University of Caen, in order to better characterize the plant cover (ecological groups and associated soils) and to observe its medium and long term evolution. Field assessments made on 10 plots were complemented by laboratory analyses carried out over a period of 1 year. The results indicate scenarios and alternative solutions which could arise, in order to passively ensure the long-term safety of the waste disposal system. Several proposals for a blanket solution are currently being studied and discussed, under the auspices of international research institutions in order to determine the most appropriate materials for the storage conditions. One proposal is an increased thickness of these materials associated with a geotechnical barrier since it is well adapted to the forest plants which are likely to colonize the site. The current experiments that are carried out will allow to select the best option and could provide feedback for other waste disposal facility sites already being operated in France (CSFMA waste disposal facility, Aube district) or in other countries.

Observed long-term greening of alpine vegetation—a case study in the French Alps

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Carlson, Bradley Z.; Corona, Monica C.; Dentant, Cédric; Bonet, Richard; Thuiller, Wilfried; Choler, Philippe

2017-11-01

We combined imagery from multiple sources (MODIS, Landsat-5, 7, 8) with land cover data to test for long-term (1984-2015) greening or browning trends of vegetation in a temperate alpine area, the Ecrins National Park, in the context of recent climate change and domestic grazing practices. We showed that over half (56%) of the Ecrins National Park displayed significant increases in peak normalized difference vegetation index (NDVImax) over the last 16 years (2000-2015). Importantly, the highest proportional increases in NDVImax occurred in rocky habitats at high elevations (> 2500 m a.s.l.). While spatial agreement in the direction of change in NDVImax as detected by MODIS and Landsat was high (76% overlap), correlations between log-response ratio values were of moderate strength (approx. 0.3). In the context of above treeline habitats, we found that proportional increases in NDVImax were higher between 1984 and 2000 than between 2000 and 2015, suggesting a slowing of greening dynamics during the recent decade. The timing of accelerated greening prior to 2000 coincided with a pronounced increase in the amount of snow-free growing degree-days that occurred during the 1980s and 1990s. In the case of grasslands and low-shrub habitats, we did not find evidence for a negative effect of grazing on greening trends, possibly due to the low grazing intensity typically found in the study area. We propose that the emergence of a longer and warmer growing season enabled high-elevation plant communities to produce more biomass, and also allowed for plant colonization of habitats previously characterized by long-lasting snow cover. Increasing plant productivity in an alpine context has potential implications for biodiversity trajectories and for ecosystem services in mountain landscapes. The presented evidence for long-term greening trends in a representative region of the European Alps provides the basis for further research on mechanisms of greening in alpine landscapes.

Modelling Soil Carbon Content in South Patagonia and Evaluating Changes According to Climate, Vegetation, Desertification and Grazing

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Pablo Luis Peri

2018-02-01

Full Text Available In Southern Patagonia, a long-term monitoring network has been established to assess bio-indicators as an early warning of environmental changes due to climate change and human activities. Soil organic carbon (SOC content in rangelands provides a range of important ecosystem services and supports the capacity of the land to sustain plant and animal productivity. The objectives in this study were to model SOC (30 cm stocks at a regional scale using climatic, topographic and vegetation variables, and to establish a baseline that can be used as an indicator of rangeland condition. For modelling, we used a stepwise multiple regression to identify variables that explain SOC variation at the landscape scale. With the SOC model, we obtained a SOC map for the entire Santa Cruz province, where the variables derived from the multiple linear regression models were integrated into a geographic information system (GIS. SOC stock to 30 cm ranged from 1.38 to 32.63 kg C m−2. The fitted model explained 76.4% of SOC variation using as independent variables isothermality, precipitation seasonality and vegetation cover expressed as a normalized difference vegetation index. The SOC map discriminated in three categories (low, medium, high determined patterns among environmental and land use variables. For example, SOC decreased with desertification due to erosion processes. The understanding and mapping of SOC in Patagonia contributes as a bridge across main issues such as climate change, desertification and biodiversity conservation.

Long term socio-ecological research across temporal and spatial scales

Science.gov (United States)

Singh, S. J.; Haberl, H.

2012-04-01

Long term socio-ecological research across temporal and spatial scales Simron Jit Singh and Helmut Haberl Institute of Social Ecology, Vienna, Austria Understanding trajectories of change in coupled socio-ecological (or human-environment) systems requires monitoring and analysis at several spatial and temporal scales. Long-term ecosystem research (LTER) is a strand of research coupled with observation systems and infrastructures (LTER sites) aimed at understanding how global change affects ecosystems around the world. In recent years it has been increasingly recognized that sustainability concerns require extending this approach to long-term socio-ecological research, i.e. a more integrated perspective that focuses on interaction processes between society and ecosystems over longer time periods. Thus, Long-Term Socio-Ecological Research, abbreviated LTSER, aims at observing, analyzing, understanding and modelling of changes in coupled socio-ecological systems over long periods of time. Indeed, the magnitude of the problems we now face is an outcome of a much longer process, accelerated by industrialisation since the nineteenth century. The paper will provide an overview of a book (in press) on LTSER with particular emphasis on 'socio-ecological transitions' in terms of material, energy and land use dynamics across temporal and spatial scales.

Changes observed in urine microbiology following replacement of long-term urinary catheters: need to modify UTI guidelines in the UK?

Science.gov (United States)

Batura, Deepak; Gopal Rao, G; Foran, Marion; Brempong, Fatmata

2018-01-01

Bacteria adherent to long-term urinary catheters (LTUC) may give misleading urine culture results. Guidelines in the USA recommend changing LTUC before urine collection to diagnose UTI and before commencing appropriate antimicrobial treatment. However, in the UK there is no such guidance. In this study, we evaluated differences in urine cultures before and after changing LTUC. In a prospective study in a UK urology department, we made a quantitative and qualitative comparison between paired urines collected before and after catheter change in patients with LTUC. We measured culture growth on a four-point ordinal scale as nil, scanty ( 10 8  cfu/L) and recorded the range of bacterial species isolated. Statistical analysis was by Wilcoxon matched-pairs test. Sixty-six patients (55 males, 11 females) took part in the study. Urines with no growth increased from 7/66 (11%) before change of catheter to 21/66(32%) after change of catheter. Cultures reported as heavy growth (> 10 8  cfu/L) reduced from 48/66 (73%) to 25/66 (38%) after catheter change (p < 0.001). Except for Pseudomonas spp., other organisms were isolated less frequently after catheter change. No Proteus spp. was isolated after catheter change. This study confirms that failure to change long-term catheters before collecting urine for culture may give misleading results. In the interest of accurate diagnosis and antimicrobial stewardship, UK guidelines should recommend changing long-term urinary catheters before collection of urine for culture.

Short-term and long-term plasticity interaction in human primary motor cortex.

Science.gov (United States)

Iezzi, Ennio; Suppa, Antonio; Conte, Antonella; Li Voti, Pietro; Bologna, Matteo; Berardelli, Alfredo

2011-05-01

Repetitive transcranial magnetic stimulation (rTMS) over primary motor cortex (M1) elicits changes in motor evoked potential (MEP) size thought to reflect short- and long-term forms of synaptic plasticity, resembling short-term potentiation (STP) and long-term potentiation/depression (LTP/LTD) observed in animal experiments. We designed this study in healthy humans to investigate whether STP as elicited by 5-Hz rTMS interferes with LTP/LTD-like plasticity induced by intermittent and continuous theta-burst stimulation (iTBS and cTBS). The effects induced by 5-Hz rTMS and iTBS/cTBS were indexed as changes in MEP size. We separately evaluated changes induced by 5-Hz rTMS, iTBS and cTBS applied alone and those induced by iTBS and cTBS delivered after priming 5-Hz rTMS. Interactions between 5-Hz rTMS and iTBS/cTBS were investigated under several experimental conditions by delivering 5-Hz rTMS at suprathreshold and subthreshold intensity, allowing 1 and 5 min intervals to elapse between 5-Hz rTMS and TBS, and delivering one and ten 5-Hz rTMS trains. We also investigated whether 5-Hz rTMS induces changes in intracortical excitability tested with paired-pulse transcranial magnetic stimulation. When given alone, 5-Hz rTMS induced short-lasting and iTBS/cTBS induced long-lasting changes in MEP amplitudes. When M1 was primed with 10 suprathreshold 5-Hz rTMS trains at 1 min before iTBS or cTBS, the iTBS/cTBS-induced after-effects disappeared. The 5-Hz rTMS left intracortical excitability unchanged. We suggest that STP elicited by suprathreshold 5-Hz rTMS abolishes iTBS/cTBS-induced LTP/LTD-like plasticity through non-homeostatic metaplasticity mechanisms. Our study provides new information on interactions between short-term and long-term rTMS-induced plasticity in human M1. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Audit of long-term and short-term liabilities

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Korinko M.D.

2017-03-01

Full Text Available The article determines the importance of long-term and short-term liabilities for the management of financial and material resources of an enterprise. It reviews the aim, objects and information generators for realization of audit of short-term and long-term obligations. The organizing and methodical providing of audit of long-term and short-term liabilities of an enterprise are generalized. The authors distinguish the stages of realization of audit of long-term and short-term liabilities, the aim of audit on each of the presented stages, and recommend methodical techniques. It is fixed that it is necessary to conduct the estimation of the systems of internal control and record-keeping of an enterprise by implementation of public accountant procedures for determination of volume and maintenance of selection realization. After estimating the indicated systems, a public accountant determines the methodology for realization of public accountant verification of long-term and short-term liabilities. The analytical procedures that public accountants are expedient to use for realization of audit of short-term and long-term obligations are determined. The authors suggest the classification of the educed defects on the results of the conducted public accountant verification of short-term and long-term obligations.

Late-Holocene vegetation dynamics in response to a changing climate and anthropogenic influences - Insights from stratigraphic records and subfossil trees from southeast Lithuania

Science.gov (United States)

Edvardsson, Johannes; Stančikaitė, Miglė; Miras, Yannick; Corona, Christophe; Gryguc, Gražyna; Gedminienė, Laura; Mažeika, Jonas; Stoffel, Markus

2018-04-01

To increase our understanding of long-term climate dynamics and its effects on different ecosystems, palaeoclimatic and long-term botanical reconstructions need to be improved, in particular in underutilized geographical regions. In this study, vegetation, (hydro)climate, and land-use changes were documented at two southeast Lithuanian peatland complexes - Čepkeliai and Rieznyčia - for the Late-Holocene period. The documentation was based on a combination of pollen, plant macrofossils, peat stratigraphic records, and subfossil trees. Our results cover the last two millennia and reveal the existence of moist conditions in Southern Lithuania between 300 and 500 CE and from 950 to 1850 CE. Conversely, changes towards warmer and/or dryer conditions have been recorded in 100, 600, and 750 CE, and since the 1850s. Significant differences with other Baltic proxies prevent deriving a complete and precise long-term reconstruction of past hydroclimatic variability at the regional scale. Yet, our results provide an important cornerstone for an improved understanding of regional climate change, i.e. in a region for which only (i) few detailed palaeobotanical studies exist and which has, in addition, been considered as (ii) an ecologically sensitive region at the interface between the temperate and boreal bioclimatic zones.

Impact of surrounding environment evolution on long-term gas flux measurements in a temperate mixed forest

Science.gov (United States)

Hurdebise, Quentin; Rixen, Toma; De Ligne, Anne; Vincke, Caroline; Heinesch, Bernard; Aubinet, Marc

2016-04-01

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: -displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; -turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; -tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; -measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into

Drivers for successful long-term lifestyle change, the role of e-health

DEFF Research Database (Denmark)

Brandt, Carl Joakim; Clemensen, Jane; Nielsen, Jesper Bo

2018-01-01

Objectives Assisting patients in lifestyle change using collaborative e-health tools can be an efficient treatment for non-communicable diseases like diabetes, cardiovascular disease and chronic obstructive lung disease that are caused or aggravated by unhealthy living in the form of unhealthy diet......, physical inactivity or tobacco smoking. In a prospective pilot study, we tested an online collaborative e-health tool in general practice. The aim of this study was to identify drivers of importance for long-term personal lifestyle changes from a patient perspective when using a collaborative e-health tool......, including the support of peers and healthcare professionals. Setting General practice clinics in the Region of Southern Denmark. Participants 10 overweight patients who had previously successfully used a hybrid online collaborative e-health tool with both face-to-face and online consultations to lose weight...

Investigation on the Patterns of Global Vegetation Change Using a Satellite-Sensed Vegetation Index

Directory of Open Access Journals (Sweden)

Ainong Li

2010-06-01

Full Text Available The pattern of vegetation change in response to global change still remains a controversial issue. A Normalized Difference Vegetation Index (NDVI dataset compiled by the Global Inventory Modeling and Mapping Studies (GIMMS was used for analysis. For the period 1982–2006, GIMMS-NDVI analysis indicated that monthly NDVI changes show homogenous trends in middle and high latitude areas in the northern hemisphere and within, or near, the Tropic of Cancer and Capricorn; with obvious spatio-temporal heterogeneity on a global scale over the past two decades. The former areas featured increasing vegetation activity during growth seasons, and the latter areas experienced an even greater amplitude in places where precipitation is adequate. The discussion suggests that one should be cautious of using the NDVI time-series to analyze local vegetation dynamics because of its coarse resolution and uncertainties.

Long-term correlated change between personality traits and perceived social support in middle adulthood

OpenAIRE

Allemand Mathias; Schaffhuser Kathrin; Martin Mike

2015-01-01

This study investigated long-term correlated change between personality traits and perceived social support in middle adulthood. Two measurement occasions with an 8-year time interval from the Interdisciplinary Longitudinal Study on Adult Development (ILSE) were used. The sample consisted of 346 middle-aged adults (46-50 years at T1). Four different types of perceived social support were assessed. Personality traits were assessed with the NEO-Five-Factor Inventory (NEO-FFI). Longitudinal meas...

Natural analogs of the long-term performance of engineered covers

International Nuclear Information System (INIS)

Waugh, W.J.; Petersen, K.L.; Link, S.O.; Bjornstad, B.N.; Gee, G.W.

1994-01-01

The unprecedented legislative demand that in-situ waste-disposal facilities effectively persist indefinitely requires a performance assessment approach that exceeds standard engineering practices and incorporates possible long-term changes in site hydrology, geology, and ecology. Even in relatively arid regions, over time, buried waste will be vulnerable to transport via rainwater percolation, gas diffusion, erosion, and intrusion by plant roots, burrowing animals, and humans. Standard models and field tests of engineered covers designed to impede these pathways implicitly and erroneously assume that initial conditions of many key determinants will persist indefinitely. Evidence from natural, archaeological, and engineered analogs is needed (1) to identify and understand emergent system attributes that cannot be captured with computer models or short-term experiments, and (2) to develop modeling and field tests that reasonably bound possible future changes in waste-site environments. Analogs of local responses to future global climate change exist as proxy ecological and archaeological records of similar paleoclimates. Future pedogenic influences can be inferred form measurements of key soil properties in natural and archaeological soil profiles analogous to engineered covers. Many cover designs depend on water extraction by plants. Influences of vegetation change can be inferred by measuring water extraction parameters in plant communities representing successional chronosequences. Habitats similar to those created on waste sites provide evidence of the potential for biological intrusion. Recent and ancient man-made structures provide evidence of the future stability of waste-site covers and of features that may discourage human intrusion. 108 refs., 4 figs

Sleep Quality, Short-Term and Long-Term CPAP Adherence

Science.gov (United States)

Somiah, Manya; Taxin, Zachary; Keating, Joseph; Mooney, Anne M.; Norman, Robert G.; Rapoport, David M.; Ayappa, Indu

2012-01-01

Study Objectives: Adherence to CPAP therapy is low in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). The purpose of the present study was to evaluate the utility of measures of sleep architecture and sleep continuity on the CPAP titration study as predictors of both short- and long-term CPAP adherence. Methods: 93 patients with OSAHS (RDI 42.8 ± 34.3/h) underwent in-laboratory diagnostic polysomnography, CPAP titration, and follow-up polysomnography (NPSG) on CPAP. Adherence to CPAP was objectively monitored. Short-term (ST) CPAP adherence was averaged over 14 days immediately following the titration study. Long-term (LT) CPAP adherence was obtained in 56/93 patients after approximately 2 months of CPAP use. Patients were grouped into CPAP adherence groups for ST ( 4 h) and LT adherence ( 4 h). Sleep architecture, sleep disordered breathing (SDB) indices, and daytime outcome variables from the diagnostic and titration NPSGs were compared between CPAP adherence groups. Results: There was a significant relationship between ST and LT CPAP adherence (r = 0.81, p CPAP adherence groups had significantly lower %N2 and greater %REM on the titration NPSG. A model combining change in sleep efficiency and change in sleep continuity between the diagnostic and titration NPSGs predicted 17% of the variance in LT adherence (p = 0.006). Conclusions: These findings demonstrate that characteristics of sleep architecture, even on the titration NPSG, may predict some of the variance in CPAP adherence. Better sleep quality on the titration night was related to better CPAP adherence, suggesting that interventions to improve sleep on/prior to the CPAP titration study might be used as a therapeutic intervention to improve CPAP adherence. Citation: Somiah M; Taxin Z; Keating J; Mooney AM; Norman RG; Rapoport DM; Ayappa I. Sleep quality, short-term and long-term CPAP adherence. J Clin Sleep Med 2012;8(5):489-500. PMID:23066359

Fresh Vegetables in the food service Industry its purchasing system; Gaishoku sangyo ni okeru seisen seikabutsu no chotatsu shisutemu

Energy Technology Data Exchange (ETDEWEB)

Oda, K. [Food Service Industry Survey and Research Center, Tokyo (Japan)

1999-09-05

The environment which surrounds production, distribution, consumption of vegetables changes. A demand for the business a household economy demand of vegetables stagnates by the increase of eating out and lunches demand in the food consumption as a long-term tendency, and the tendency as vigorousness continues. In addition, a demand for domestic organic and special cultivation vegetables from the increase of the healthy and safe orientation of the consumer heightens. In this paper, what kind of new movement occurs in environmental change which surrounds these vegetables is arranged. (NEDO)

Repeatability of riparian vegetation sampling methods: how useful are these techniques for broad-scale, long-term monitoring?

Science.gov (United States)

Marc C. Coles-Ritchie; Richard C. Henderson; Eric K. Archer; Caroline Kennedy; Jeffrey L. Kershner

2004-01-01

Tests were conducted to evaluate variability among observers for riparian vegetation data collection methods and data reduction techniques. The methods are used as part of a largescale monitoring program designed to detect changes in riparian resource conditions on Federal lands. Methods were evaluated using agreement matrices, the Bray-Curtis dissimilarity metric, the...

Globally Increased Crop Growth and Cropping Intensity from the Long-Term Satellite-Based Observations

Science.gov (United States)

Chen, Bin

2018-04-01

Understanding the spatiotemporal change trend of global crop growth and multiple cropping system under climate change scenarios is a critical requirement for supporting the food security issue that maintains the function of human society. Many studies have predicted the effects of climate changes on crop production using a combination of filed studies and models, but there has been limited evidence relating decadal-scale climate change to global crop growth and the spatiotemporal distribution of multiple cropping system. Using long-term satellite-derived Normalized Difference Vegetation Index (NDVI) and observed climate data from 1982 to 2012, we investigated the crop growth trend, spatiotemporal pattern trend of agricultural cropping intensity, and their potential correlations with respect to the climate change drivers at a global scale. Results show that 82.97 % of global cropland maximum NDVI witnesses an increased trend while 17.03 % of that shows a decreased trend over the past three decades. The spatial distribution of multiple cropping system is observed to expand from lower latitude to higher latitude, and the increased cropping intensity is also witnessed globally. In terms of regional major crop zones, results show that all nine selected zones have an obvious upward trend of crop maximum NDVI (p impact on the crop growth trend.

Changes in prefrontal-limbic function in major depression after 15 months of long-term psychotherapy.

Directory of Open Access Journals (Sweden)

Anna Buchheim

Full Text Available Neuroimaging studies of depression have demonstrated treatment-specific changes involving the limbic system and regulatory regions in the prefrontal cortex. While these studies have examined the effect of short-term, interpersonal or cognitive-behavioural psychotherapy, the effect of long-term, psychodynamic intervention has never been assessed. Here, we investigated recurrently depressed (DSM-IV unmedicated outpatients (N = 16 and control participants matched for sex, age, and education (N = 17 before and after 15 months of psychodynamic psychotherapy. Participants were scanned at two time points, during which presentations of attachment-related scenes with neutral descriptions alternated with descriptions containing personal core sentences previously extracted from an attachment interview. Outcome measure was the interaction of the signal difference between personal and neutral presentations with group and time, and its association with symptom improvement during therapy. Signal associated with processing personalized attachment material varied in patients from baseline to endpoint, but not in healthy controls. Patients showed a higher activation in the left anterior hippocampus/amygdala, subgenual cingulate, and medial prefrontal cortex before treatment and a reduction in these areas after 15 months. This reduction was associated with improvement in depressiveness specifically, and in the medial prefrontal cortex with symptom improvement more generally. This is the first study documenting neurobiological changes in circuits implicated in emotional reactivity and control after long-term psychodynamic psychotherapy.

Changes in Prefrontal-Limbic Function in Major Depression after 15 Months of Long-Term Psychotherapy

Science.gov (United States)

Buchheim, Anna; Viviani, Roberto; Kessler, Henrik; Kächele, Horst; Cierpka, Manfred; Roth, Gerhard; George, Carol; Kernberg, Otto F.; Bruns, Georg; Taubner, Svenja

2012-01-01

Neuroimaging studies of depression have demonstrated treatment-specific changes involving the limbic system and regulatory regions in the prefrontal cortex. While these studies have examined the effect of short-term, interpersonal or cognitive-behavioural psychotherapy, the effect of long-term, psychodynamic intervention has never been assessed. Here, we investigated recurrently depressed (DSM-IV) unmedicated outpatients (N = 16) and control participants matched for sex, age, and education (N = 17) before and after 15 months of psychodynamic psychotherapy. Participants were scanned at two time points, during which presentations of attachment-related scenes with neutral descriptions alternated with descriptions containing personal core sentences previously extracted from an attachment interview. Outcome measure was the interaction of the signal difference between personal and neutral presentations with group and time, and its association with symptom improvement during therapy. Signal associated with processing personalized attachment material varied in patients from baseline to endpoint, but not in healthy controls. Patients showed a higher activation in the left anterior hippocampus/amygdala, subgenual cingulate, and medial prefrontal cortex before treatment and a reduction in these areas after 15 months. This reduction was associated with improvement in depressiveness specifically, and in the medial prefrontal cortex with symptom improvement more generally. This is the first study documenting neurobiological changes in circuits implicated in emotional reactivity and control after long-term psychodynamic psychotherapy. PMID:22470470

Long-term follow-up study and long-term care of childhood cancer survivors

Directory of Open Access Journals (Sweden)

Hyeon Jin Park

2010-04-01

Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

Diagnosis of vegetation recovery within herbaceous sub-systems in the West African Sahel Region

Science.gov (United States)

Anchang, J.; Hanan, N. P.; Prihodko, L.; Sathyachandran, S. K.; Ji, W.; Ross, C. W.

2017-12-01

The West African Sahel (WAS) region is an extensive water limited environment that features a delicate balance of herbaceous and woody vegetation sub systems. These play an important role in the cycling of carbon while also supporting the dominant agro-pastoral human activities in the region. Quantifying the temporal trends in vegetation with regard to these two systems is therefore very important in assessing resource sustainability and food security. In water limited areas, rainfall is a primary driver of vegetation productivity and past watershed scale studies in the WAS region have shown that increase in the slope of the productivity-to-rainfall relationship is indicative of increasing cover and density of herbaceous plants. Given the importance of grazing resources to the region, we perform a wall-to-wall pixel based analysis of changing short-term vegetation sensitivity to changing annual rainfall (hereafter referred to as dS) to examine temporal trends in herbaceous vegetation health. Results indicate that 43% of the Sahelian region has experienced changes (P Western and Central Mali and South Western Niger. Positive dS is indicative of herbaceous vegetation recovery, in response to changing management and rainfall conditions that promote long-term herbaceous community recovery following degradation during the 1970-1980s droughts.

The future of spaceborne altimetry. Oceans and climate change: A long-term strategy

Science.gov (United States)

Koblinsky, C. J. (Editor); Gaspar, P. (Editor); Lagerloef, G. (Editor)

1992-01-01

The ocean circulation and polar ice sheet volumes provide important memory and control functions in the global climate. Their long term variations are unknown and need to be understood before meaningful appraisals of climate change can be made. Satellite altimetry is the only method for providing global information on the ocean circulation and ice sheet volume. A robust altimeter measurement program is planned which will initiate global observations of the ocean circulation and polar ice sheets. In order to provide useful data about the climate, these measurements must be continued with unbroken coverage into the next century. Herein, past results of the role of the ocean in the climate system is summarized, near term goals are outlined, and requirements and options are presented for future altimeter missions. There are three basic scientific objectives for the program: ocean circulation; polar ice sheets; and mean sea level change. The greatest scientific benefit will be achieved with a series of dedicated high precision altimeter spacecraft, for which the choice of orbit parameters and system accuracy are unencumbered by requirements of companion instruments.

The future of spaceborne altimetry. Oceans and climate change: A long-term strategy

International Nuclear Information System (INIS)

Koblinsky, C.J.; Gaspar, P.; Lagerloef, G.

1992-03-01

The ocean circulation and polar ice sheet volumes provide important memory and control functions in the global climate. Their long term variations are unknown and need to be understood before meaningful appraisals of climate change can be made. Satellite altimetry is the only method for providing global information on the ocean circulation and ice sheet volume. A robust altimeter measurement program is planned which will initiate global observations of the ocean circulation and polar ice sheets. In order to provide useful data about the climate, these measurements must be continued with unbroken coverage into the next century. Herein, past results of the role of the ocean in the climate system is summarized, near term goals are outlined, and requirements and options are presented for future altimeter missions. There are three basic scientific objectives for the program: ocean circulation; polar ice sheets; and mean sea level change. The greatest scientific benefit will be achieved with a series of dedicated high precision altimeter spacecraft, for which the choice of orbit parameters and system accuracy are unencumbered by requirements of companion instruments

Detecting changes in real-world objects: The relationship between visual long-term memory and change blindness.

Science.gov (United States)

Brady, Timothy F; Konkle, Talia; Oliva, Aude; Alvarez, George A

2009-01-01

A large body of literature has shown that observers often fail to notice significant changes in visual scenes, even when these changes happen right in front of their eyes. For instance, people often fail to notice if their conversation partner is switched to another person, or if large background objects suddenly disappear.1,2 These 'change blindness' studies have led to the inference that the amount of information we remember about each item in a visual scene may be quite low.1 However, in recent work we have demonstrated that long-term memory is capable of storing a massive number of visual objects with significant detail about each item.3 In the present paper we attempt to reconcile these findings by demonstrating that observers do not experience 'change blindness' with the real world objects used in our previous experiment if they are given sufficient time to encode each item. The results reported here suggest that one of the major causes of change blindness for real-world objects is a lack of encoding time or attention to each object (see also refs. 4 and 5).

The long-term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA

Science.gov (United States)

Kui, Li; Stella, John C.; Shafroth, Patrick B.; House, P. Kyle; Wilcox, Andrew C.

2017-01-01

On alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56-year series of aerial photos on the dammed Bill Williams River (Arizona, USA) to investigate how (a) different woody riparian vegetation types influence river channel planform and (b) how different fluvial landforms drive the composition of riparian plant communities over time. We mapped vegetation types and geomorphic surfaces and quantified how relations between fluvial and biotic processes covaried over time using linear mixed models. In the decades after the dam was built, woody plant cover within the river's bottomland nearly doubled, narrowing the active channel by 60% and transforming its planform from wide and braided to a single thread and more sinuous channel. Compared with native cottonwood–willow vegetation, nonnative tamarisk locally induced a twofold greater reduction in channel braiding. Vegetation expanded at different rates depending on the type of landform, with tamarisk cover on former high-flow channels increasing 17% faster than cottonwood–willow. Former low-flow channels with frequent inundation supported a greater increase in cottonwood–willow relative to tamarisk. These findings give insight into how feedbacks between abiotic and biotic processes in river channels accelerate and fortify changes triggered by dam construction, creating river systems increasingly distinct from predam ecological communities and landforms, and progressively more resistant to restoration of predam forms and processes.

Assessing climate change and socio-economic uncertainties in long term management of water resources

Science.gov (United States)

Jahanshahi, Golnaz; Dawson, Richard; Walsh, Claire; Birkinshaw, Stephen; Glenis, Vassilis

2015-04-01

Long term management of water resources is challenging for decision makers given the range of uncertainties that exist. Such uncertainties are a function of long term drivers of change, such as climate, environmental loadings, demography, land use and other socio economic drivers. Impacts of climate change on frequency of extreme events such as drought make it a serious threat to water resources and water security. The release of probabilistic climate information, such as the UKCP09 scenarios, provides improved understanding of some uncertainties in climate models. This has motivated a more rigorous approach to dealing with other uncertainties in order to understand the sensitivity of investment decisions to future uncertainty and identify adaptation options that are as far as possible robust. We have developed and coupled a system of models that includes a weather generator, simulations of catchment hydrology, demand for water and the water resource system. This integrated model has been applied in the Thames catchment which supplies the city of London, UK. This region is one of the driest in the UK and hence sensitive to water availability. In addition, it is one of the fastest growing parts of the UK and plays an important economic role. Key uncertainties in long term water resources in the Thames catchment, many of which result from earth system processes, are identified and quantified. The implications of these uncertainties are explored using a combination of uncertainty analysis and sensitivity testing. The analysis shows considerable uncertainty in future rainfall, river flow and consequently water resource. For example, results indicate that by the 2050s, low flow (Q95) in the Thames catchment will range from -44 to +9% compared with the control scenario (1970s). Consequently, by the 2050s the average number of drought days are expected to increase 4-6 times relative to the 1970s. Uncertainties associated with urban growth increase these risks further

Effects of metals on vegetation

Energy Technology Data Exchange (ETDEWEB)

Press, N P

1972-01-01

Prospectors have long known that abnormal concentrations of metals in the soil overlying an ore deposit can affect the vegetation rooting in this soil; mineral deposits have even been discovered because of such vegetation changes. Recently, many people have become interested in the possibility of remote sensing such vegetation changes, and perhaps using the results in conjunction with airborne geophysics and photogeological interpretation in integrated prospecting programs.

Timber joints under long-term loading

DEFF Research Database (Denmark)

Feldborg, T.; Johansen, M.

This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were...... integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering....

Future climate change is predicted to shift long-term persistence zones in the cold-temperate kelp Laminaria hyperborea.

Science.gov (United States)

Assis, Jorge; Lucas, Ana Vaz; Bárbara, Ignacio; Serrão, Ester Álvares

2016-02-01

Global climate change is shifting species distributions worldwide. At rear edges (warmer, low latitude range margins), the consequences of small variations in environmental conditions can be magnified, producing large negative effects on species ranges. A major outcome of shifts in distributions that only recently received attention is the potential to reduce the levels of intra-specific diversity and consequently the global evolutionary and adaptive capacity of species to face novel disturbances. This is particularly important for low dispersal marine species, such as kelps, that generally retain high and unique genetic diversity at rear ranges resulting from long-term persistence, while ranges shifts during climatic glacial/interglacial cycles. Using ecological niche modelling, we (1) infer the major environmental forces shaping the distribution of a cold-temperate kelp, Laminaria hyperborea (Gunnerus) Foslie, and we (2) predict the effect of past climate changes in shaping regions of long-term persistence (i.e., climatic refugia), where this species might hypothetically harbour higher genetic diversity given the absence of bottlenecks and local extinctions over the long term. We further (3) assessed the consequences of future climate for the fate of L. hyperborea using different scenarios of greenhouse gas emissions (RCP 2.6 and RCP 8.5). Results show NW Iberia, SW Ireland and W English Channel, Faroe Islands and S Iceland, as regions where L. hyperborea may have persisted during past climate extremes until present day. All predictions for the future showed expansions to northern territories coupled with the significant loss of suitable habitats at low latitude range margins, where long-term persistence was inferred (e.g., NW Iberia). This pattern was particularly evident in the most agressive scenario of climate change (RCP 8.5), likely driving major biodiversity loss, changes in ecosystem functioning and the impoverishment of the global gene pool of L

Assessing the market for long-term care services.

Science.gov (United States)

Rice, J A; Taylor, S

1984-02-01

Traditionally, long-term care services have been used by a diverse marketplace. The chronically ill, developmentally disabled, mentally ill and aging population has looked to long-term care support services as a means of physical and emotional support. Much of the time these services were housed together for the sake of efficiency. The enormous burden these services are creating on the economy, and the growing aging population, have forced the recognition that long-term care service delivery systems must change. Alternate programming for long-term care services that reach out into the community and into individual homes is becoming an attractive approach to meeting the growing demands of the marketplace. Home health, specialized housing and creative funding mechanisms such as HMOs, are examples of initiatives undertaken by healthcare organizations that view diversification as a vehicle for survival. Market research techniques that have been used in other industries are being adapted to the healthcare industry to ensure the proper mix of services that are demanded by older, more knowledgeable consumers. The programs of the future will be market driven, with the ability of the individual to pay for such services playing a significant role. The healthcare provider of today is in a position to serve the community in new ways. By becoming an integral link in the long-term care system and by developing new programs, the organization can serve as a catalyst for change. It is up to the governing bodies and managers of these facilities to become visionaries and to accept responsibility for assessing the market for long-term care services and to guide their organization into the future.

Long-term changes in community assembly, resistance, and resilience following experimental floods.

Science.gov (United States)

Robinson, Christopher T

2012-10-01

This study examined the long-term changes in community assembly, resistance, and resilience of macroinvertebrates following 10 years of experimental floods in a flow regulated river. Physico-chemistry, macroinvertebrates, and periphyton biomass were monitored before and sequentially after each of 22 floods, and drift/seston was collected during six separate floods over the study period. The floods reduced the density and taxon richness of macroinvertebrates, and a nonmetric dimensional scaling (NMDS) analysis distinguished temporal shifts in community assembly. Resistance (measured as the relative lack of loss in density) tofloods varied among taxa, and the abundance of resistant taxa was related to the temporal changes in community assembly. Community resistance was inversely related to flood magnitude with all larger floods (> 25 m3/s, > 16-fold over baseflow) reducing densities by > 75% regardless of flood year, whereas smaller floods (floods. No relationship was found between flood magnitude and the relative loss in periphyton biomass. Resilience was defined as the recovery slope (positive slope of a parameter with time following each flood) and was unrelated to shifts in community assembly or resistance. Macroinvertebrate drift and seston demonstrated hysteresis (i.e., a temporal response in parameter quantity with change in discharge) during each flood, although larger floods typically had two peaks in both parameters. The first peak was a response to the initial increases in flow, whereas the second peak was associated with streambed disturbance (substrate mobility) and side-slope failure causing increased scour. Drift density was 3-9 times greater and that of seston 3-30 times greater during larger floods than smaller floods. These results demonstrate temporal shifts in macroinvertebrate community assembly toward a pre-dam assemblage following sequential floods in this flow regulated river, thus confirming the ecological role of habitat filtering in

Histomorphometric examination of long-term changes in temporomandibular joints after mandibular lengthening by distraction osteogenesis in rabbits.

Science.gov (United States)

Mihmanli, Ahmet; Dolanmaz, Doğan; Tüz, Hakan; Pampu, Alper; Dönmez, Hasan Hüseyin

2012-05-01

The purpose of this study was to evaluate long-term histomorphometric changes in temporomandibular joints (TMJs) of rabbits after mandibular distraction osteogenesis (DO). Twenty-six rabbits were used in this study. Two of them served as control subjects, and the remaining 24 underwent DO procedures in their left mandibular bodies. After a latency period of 5 days, 5 mm lengthening was performed at a rate of 1 mm/d. The rabbits in the experimental group were randomly divided into 4 subgroups and killed after 1, 2, 4, and 6 months. TMJs from both sides were harvested and prepared with hematoxylin and eosin stain for histomorphometric examination under an optical microscope. Compared with control subjects and nondistracted sides, fibrous articular, proliferative, and hypertrophic areas were significantly increased (P distracted sides. The changes were insignificant in the fourth and sixth postoperative months. Unilateral mandibular distraction of 5 mm was found to be well tolerated and no degenerative changes were observed histologically in the rabbit TMJs in the long-term period. Copyright © 2012 Elsevier Inc. All rights reserved.

Nonparametric Monitoring for Geotechnical Structures Subject to Long-Term Environmental Change

Directory of Open Access Journals (Sweden)

Hae-Bum Yun

2011-01-01

Full Text Available A nonparametric, data-driven methodology of monitoring for geotechnical structures subject to long-term environmental change is discussed. Avoiding physical assumptions or excessive simplification of the monitored structures, the nonparametric monitoring methodology presented in this paper provides reliable performance-related information particularly when the collection of sensor data is limited. For the validation of the nonparametric methodology, a field case study was performed using a full-scale retaining wall, which had been monitored for three years using three tilt gauges. Using the very limited sensor data, it is demonstrated that important performance-related information, such as drainage performance and sensor damage, could be disentangled from significant daily, seasonal and multiyear environmental variations. Extensive literature review on recent developments of parametric and nonparametric data processing techniques for geotechnical applications is also presented.

Modern High Technology Solutions for Quality and Longterm Vegetable Preservation

International Nuclear Information System (INIS)

Nacheva, I.; Miteva, D.; Todorov, Y.; Loginovska, K.; Tsvetkov, Ts.

2012-01-01

In the publication the authors present the results of the applying of two modern technologies for long term and safe vegetable preservation – freeze-drying and gamma sterilization. The freeze-dried vegetables feature minimum moisture – from 2 – 5% and taste-aroma complex preserved to the highest degree. The carried out gamma sterilization ensures a high microbial purity of the vegetables and guarantees for their long term preservation - up to 5 years in polymer packing, under usual conditions

The Structure and Content of Long-Term and Short-Term Mate Preferences

Directory of Open Access Journals (Sweden)

Peter K. Jonason

2013-12-01

Full Text Available This study addresses two limitations in the mate preferences literature. First, research all-too-often relies on single-item assessments of mate preferences precluding more advanced statistical techniques like factor analysis. Second, when factor analysis could be done, it exclusively has done for long-term mate preferences, at the exclusion of short-term mate preferences. In this study (N = 401, we subjected 20 items designed to measure short- and long-term mate preferences to both principle components (n = 200 and confirmatory factor analysis (n = 201. In the long-term context, we replicated previous findings that there are three different categories of preferences: physical attractiveness, interpersonal warmth, and social status. In the short-term context, physical attractiveness occupied two parts of the structure, social status dropped out, and interpersonal warmth remained. Across short- and long-term contexts, there were slight changes in what defined the shared dimensions (i.e., physical attractiveness and interpersonal warmth, suggesting prior work that applies the same inventory to each context might be flawed. We also replicated sex differences and similarities in mate preferences and correlates with sociosexuality and mate value. We adopt an evolutionary paradigm to understand our results.

Long-Term Developmental Changes in Children's Lower-Order Big Five Personality Facets.

Science.gov (United States)

de Haan, Amaranta; De Pauw, Sarah; van den Akker, Alithe; Deković, Maja; Prinzie, Peter

2017-10-01

This study examined long-term developmental changes in mother-rated lower-order facets of children's Big Five dimensions. Two independent community samples covering early childhood (2-4.5 years; N = 365, 39% girls) and middle childhood to the end of middle adolescence (6-17 years; N = 579, 50% girls) were used. All children had the Belgian nationality. Developmental changes were examined using cohort-sequential latent growth modeling on the 18 facets of the Hierarchical Personality Inventory for Children. In early childhood, changes were mostly similar across child gender. Between 2 and 4.5 years, several facets showed mean-level stability; others changed in the direction of less Extraversion and Emotional Stability, and more Benevolence and Imagination. The lower-order facets of Conscientiousness showed opposite changes. Gender differences became more apparent from middle childhood onward for facets of all dimensions except Imagination, for which no gender differences were found. Between 6 and 17 years, same-dimension facets showed different shapes of growth. Facets that changed linearly changed mostly in the direction of less Extraversion, Benevolence, Conscientiousness, Emotional Stability, and Imagination. Changes in facets for which nonlinear growth was found generally moved in direction or magnitude during developmental transitions. This study provides comprehensive, fine-grained knowledge about personality development during the first two decades of life. © 2016 Wiley Periodicals, Inc.

Binge-pattern alcohol exposure during puberty induces long-term changes in HPA axis reactivity.

Directory of Open Access Journals (Sweden)

Magdalena M Przybycien-Szymanska

2011-04-01

Full Text Available Adolescence is a dynamic and important period of brain development however, little is known about the long-term neurobiological consequences of alcohol consumption during puberty. Our previous studies showed that binge-pattern ethanol (EtOH treatment during pubertal development negatively dysregulated the responsiveness of the hypothalamo-pituitary-adrenal (HPA axis, as manifested by alterations in corticotrophin-releasing hormone (CRH, arginine vasopressin (AVP, and corticosterone (CORT during this time period. Thus, the primary goal of this study was to determine whether these observed changes in important central regulators of the stress response were permanent or transient. In this study, juvenile male Wistar rats were treated with a binge-pattern EtOH treatment paradigm or saline alone for 8 days. The animals were left undisturbed until adulthood when they received a second round of treatments consisting of saline alone, a single dose of EtOH, or a second binge-pattern treatment paradigm. The results showed that pubertal binge-pattern EtOH exposure induced striking long-lasting alterations of many HPA axis parameters. Overall, our data provide strong evidence that binge-pattern EtOH exposure during pubertal maturation has long-term detrimental effects for the healthy development of the HPA axis.

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

Science.gov (United States)

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

2016-01-01

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

Effects of short term and long term soil warming on ecosystem phenology of a sub-arctic grassland: an NDVI-based approach

Science.gov (United States)

Leblans, Niki; Sigurdsson, Bjarni D.; Janssens, Ivan A.

2014-05-01

Phenology has been defined as the study of the timing of recurring biological events and the causes of their timing with regard to abiotic and biotic factors. Ecosystem phenology, including the onset of the growing season and its senescence in autumn, plays an important role in the carbon, water and energy exchange between biosphere and atmosphere at higher latitudes. Factors that influence ecosystem phenology can therefore induce important climate-controlling feedback mechanisms. Global surface temperatures have been predicted to increase in the coming decades. Hence, a better understanding of the effect of temperature on ecosystem phenology is essential. Natural geothermal soil temperature gradients in Iceland offer a unique opportunity to study the soil temperature (Ts) dependence of ecosystem phenology and distinguish short-term (transient) warming effects (in recently established Ts gradients) from long-term (permanent) effects (in centuries-old Ts gradients). This research was performed in the framework of an international research project (ForHot; www.forhot.is). ForHot includes two natural grassland areas with gradients in Ts, dominated by Festuca sp., Agrostis sp.. The first warmed area was created in 2008, when an earthquake in S-Iceland caused geothermal systems to be shifted to previously cold soils. The second area is located about 3 km away from this newly warmed grassland. For this area, there are proofs that the natural soil warming has been continuous for at least 300 year. In the present study we focus on Ts elevation gradients of +0 to +10°C. The experiment consists of five transects with five temperature levels (+0,+1,+3,+5 and +10°C) in the two aforementioned grassland ecosystems (n=25 in each grassland). From April until November 2013, weekly measurements of the normalized difference vegetation index (NDVI) were taken. In the short-term warmed grassland, the greening of the vegetation was 36 days advanced at +10°C Ts and the date of 50

Anticipatory eye movements and long-term memory in early infancy.

Science.gov (United States)

Wong-Kee-You, Audrey M B; Adler, Scott A

2016-11-01

Advances in our understanding of long-term memory in early infancy have been made possible by studies that have used the Rovee-Collier's mobile conjugate reinforcement paradigm and its variants. One function that has been attributed to long-term memory is the formation of expectations (Rovee-Collier & Hayne, 1987); consequently, a long-term memory representation should be established during expectation formation. To examine this prediction and potentially open the door on a new paradigm for exploring infants' long-term memory, using the Visual Expectation Paradigm (Haith, Hazan, & Goodman, 1988), 3-month-old infants were trained to form an expectation for predictable color and spatial information of picture events and emit anticipatory eye movements to those events. One day later, infants' anticipatory eye movements decreased in number relative to the end of training when the predictable colors were changed but not when the spatial location of the predictable color events was changed. These findings confirm that information encoded during expectation formation are stored in long-term memory, as hypothesized by Rovee-Collier and colleagues. Further, this research suggests that eye movements are potentially viable measures of long-term memory in infancy, providing confirmatory evidence for early mnemonic processes. © 2016 Wiley Periodicals, Inc.

Evolution of the vegetation system in the Heihe River basin in the last 2000 years

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S. Li

2017-08-01

Full Text Available The response of vegetation systems to the long-term changes in climate, hydrology, and social–economic conditions in river basins is critical for sustainable river basin management. This study aims to investigate the evolution of natural and crop vegetation systems in the Heihe River basin (HRB over the past 2000 years. Archived Landsat images, historical land use maps and hydrological records were introduced to derive the long-term spatial distribution of natural and crop vegetation and the corresponding biomass levels. The major findings are that (1 both natural and crop vegetation experienced three development stages: a pre-development stage (before the Republic of China, a rapid development stage (Republic of China – 2000, and a post-development stage (after 2000. Climate and hydrological conditions did not show significant impacts over crop vegetation, while streamflow presented synchronous changes with natural vegetation in the first stage. For the second stage, warmer temperature and increasing streamflow were found to be important factors for the increase in both natural and crop vegetation in the middle reaches of the HRB. For the third stage, positive climate and hydrological conditions, together with policy interventions, supported the overall vegetation increase in both the middle and lower HRB; (2 there was a significantly faster increase in crop biomass than that of native vegetation since 1949, which could be explained by the technological development; and (3 the ratio of natural vegetation to crop vegetation decreased from 16 during the Yuan Dynasty to about 2.2 since 2005. This ratio reflects the reaction of land and water development to a changing climate and altering social–economic conditions at the river basin level; therefore, it could be used as an indicator of water and land management at river basins.

Interactions of Flow, Sediment Transport, and Vegetation in the Long-Term Evolution of Arroyos

Science.gov (United States)

Perignon, M. C.; Griffin, E. R.; Tucker, G. E.; Friedman, J. M.; Overeem, I.

2014-12-01

Arroyos in the Southwestern United States have experienced multiple cut-and-fill cycles in the late Quaternary. Extensive studies fo the Lower Rio Puerco, New Mexico, USA, show that it has most recently progressed from an (1) unincised state with a broad floodplain in the mid 1800s, through a period of (2) incision, forming a deep gully with steep walls by the early 1900s, and to the (3) present-day stage of arroyo widening and filling. The arroyo cycle is driven by a combination of autogenic processes and external forcings, although the relative influence of each process is under debate. We use the morphodynamic model ANUGA to explore the influences of discharge, sediment transport, and vegetation on the geomorphic evolution of the Lower Rio Puerco through the arroyo cycle. The predictive power of the numerical model is first established by using it to hind-cast the morphologic evolution of a reach of the river during a large flood in 2006, and comparing the model predictions to real-world magnitudes and patterns of topographic change recorded for this event by multi-temporal airborne lidar. The morphodynamic model is then used to simulate the response of this stream to floods in the past. A comprehensive dataset of the topography and hydrology of the Lower Rio Puerco since the 1920s is used to reproduce the morphology of the arroyo at multiple points in time, and historical descriptions serve to extrapolate these into the 19th century. We test the sensitivity of the reconstructed landscapes to changes in peak discharge, sediment supply, and the distribution and characteristics of vegetation in order to determine the relative influence of each forcing in the evolution of the stream, and to understand how the interactions of different processes could drive its progression through the arroyo cycle.

Comparison of vegetable shortening and cocoa butter as vehicles for cortisol manipulation in Salmo trutta

DEFF Research Database (Denmark)

Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, M. H.

2018-01-01

This study demonstrates that vegetable shortening and cocoa butter are two effective vehicles for intraperitoneal cortisol implants in juvenile teleosts, specifically brown trout Salmo trutta, residing in north temperate freshwater environments. Each vehicle showed a different pattern of cortisol...... elevation. Vegetable shortening was found to be a more suitable vehicle for long-term cortisol elevation [elevated at 3, 6 and 9 days post treatment (dpt)], while cocoa butter may be better suited for short-term cortisol elevation (only elevated at 3 dpt). Additionally, plasma cortisol levels were higher...... with cortisol–vegetable shortening than with cortisol–cocoa butter implants. Plasma glucose levels were elevated 6 and 9 dpt for fishes injected with cortisol–vegetable shortening, but did not change relative to controls and shams in cortisol–cocoa butter fishes. In conclusion, vegetable shortening and cocoa...

Vegetation Change in Blue Oak Woodlands in California

Science.gov (United States)

Barbara A. Holzman; Barbara H. Allen-Diaz

1991-01-01

A preliminary report of a statewide project investigating vegetation change in blue oak (Quercus douglasii) woodlands in California is presented. Vegetation plots taken in the 1930s, as part of a statewide vegetation mapping project, were relocated and surveyed. Species composition, cover and tree stand structure data from the earlier study were...

Long-term deforestation in NW Spain: linking the Holocene fire history to vegetation change and human activities

Science.gov (United States)

Kaal, Joeri; Carrión Marco, Yolanda; Asouti, Eleni; Martín Seijo, Maria; Martínez Cortizas, Antonio; Costa Casáis, Manuela; Criado Boado, Felipe

2011-01-01

The Holocene fire regime is thought to have had a key role in deforestation and shrubland expansion in Galicia (NW Spain) but the contribution of past societies to vegetation burning remains poorly understood. This may be, in part, due to the fact that detailed fire records from areas in close proximity to archaeological sites are scarce. To fill this gap, we performed charcoal analysis in five colluvial soils from an archaeological area (Campo Lameiro) and compared the results to earlier studies from this area and palaeo-ecological literature from NW Spain. This analysis allowed for the reconstruction of the vegetation and fire dynamics in the area during the last ca 11 000 yrs. In the Early Holocene, Fabaceae and Betula sp. were dominant in the charcoal record. Quercus sp. started to replace these species around 10 000 cal BP, forming a deciduous forest that prevailed during the Holocene Thermal Maximum until ˜5500 cal BP. Following that, several cycles of potentially fire-induced forest regression with subsequent incomplete recovery eventually led to the formation of an open landscape dominated by shrubs (Erica sp. and Fabaceae). Major episodes of forest regression were (1) ˜5500-5000 cal BP, which marks the mid-Holocene cooling after the Holocene Thermal Maximum, but also the period during which agropastoral activities in NW Spain became widespread, and (2) ˜2000-1500 cal BP, which corresponds roughly to the end of the Roman Warm Period and the transition from the Roman to the Germanic period. The low degree of chronological precision, which is inherent in fire history reconstructions from colluvial soils, made it impossible to distinguish climatic from human-induced fires. Nonetheless, the abundance of synanthropic pollen indicators (e.g. Plantago lanceolata and Urtica dioica) since at least ˜6000 cal BP strongly suggests that humans used fire to generate and maintain pasture.

Climate change and spatial distribution of vegetation in Colombia

Directory of Open Access Journals (Sweden)

Juan Carlos Alarcon Hincapie

2013-12-01

Full Text Available Vegetation change under two climate change scenarios in different periods of the 21st Century are modeled for Colombia. Vegetation for the years 1970 to 2000 was reproduced using the Holdridge model with climate data with a spatial resolution of 900 meters. The vegetation types that occupied the most territory were sub-humid tropical forest, tropical dry forest and Andean wet forest. These results were validated by comparing with the Colombian ecosystem map (SINA, 2007, which confirmed a high degree of similarity between the modeled spatial vegetation patterns and modern ecosystem distributions. Future vegetation maps were simulated using data generated by a regional climate model under two scenarios (A2 and B2; IPCC, 2007 for the periods 2011-2040 and 2070-2100. Based on our predictions high altitude vegetation will convert to that of lower altitudes and drier provinces with the most dramatic change occurring in the A2 scenario from 2070-2100. The most affected areas are the páramo and other high Andean vegetation types, which in the timeframe of the explored scenarios will disappear by the middle of the 21st Century.

GLOBALLY INCREASED CROP GROWTH AND CROPPING INTENSITY FROM THE LONG-TERM SATELLITE-BASED OBSERVATIONS

Directory of Open Access Journals (Sweden)

B. Chen

2018-04-01

Full Text Available Understanding the spatiotemporal change trend of global crop growth and multiple cropping system under climate change scenarios is a critical requirement for supporting the food security issue that maintains the function of human society. Many studies have predicted the effects of climate changes on crop production using a combination of filed studies and models, but there has been limited evidence relating decadal-scale climate change to global crop growth and the spatiotemporal distribution of multiple cropping system. Using long-term satellite-derived Normalized Difference Vegetation Index (NDVI and observed climate data from 1982 to 2012, we investigated the crop growth trend, spatiotemporal pattern trend of agricultural cropping intensity, and their potential correlations with respect to the climate change drivers at a global scale. Results show that 82.97 % of global cropland maximum NDVI witnesses an increased trend while 17.03 % of that shows a decreased trend over the past three decades. The spatial distribution of multiple cropping system is observed to expand from lower latitude to higher latitude, and the increased cropping intensity is also witnessed globally. In terms of regional major crop zones, results show that all nine selected zones have an obvious upward trend of crop maximum NDVI (p < 0.001, and as for climatic drivers, the gradual temperature and precipitation changes have had a measurable impact on the crop growth trend.

Long-term stabilization of uranium mill tailings

International Nuclear Information System (INIS)

Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

1983-01-01

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

A study of the long-term effect of malar fat repositioning in face lift surgery: short-term success but long-term failure.

Science.gov (United States)

Hamra, Sam T

2002-09-01

In 1990, the author reported on a series of 403 cases of deep plane face lifts, the first published technique describing the repositioning of the cheek fat, known as malar fat, in face lift surgery. This study examines the long-term results of 20 of the original series in an attempt to determine what areas of the rejuvenated face (specifically, the malar fat) showed long-term improvement. The results were judged by comparing the preoperative and long-term postoperative views in a half-and-half same-side hemiface photograph. The anatomy of the jawline (superficial musculoaponeurotic system [SMAS]), the nasolabial fold (malar fat), and the periorbital diameter were evaluated. The results confirmed that repositioning of the SMAS remained for longer than improvement in the nasolabial fold and that the vertical diameter of the periorbit did not change at all. The early results of malar fat repositioning shown at 1 to 2 years were successful, but the long-term results showed failure of the early improvement, manifested by recurrence of the nasolabial folds. There was, however, continuation of the improved results of the forehead lift and SMAS maneuvers of the original procedure. The conclusion is that only a direct excision will produce a permanent correction of the aging nasolabial fold.

Long-term habitat changes in a protected area: Implications for herpetofauna habitat management and restoration.

Directory of Open Access Journals (Sweden)

Chantel E Markle

Full Text Available Point Pelee National Park, located at the southern-most tip of Canada's mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931-2015 and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.

Long-term habitat changes in a protected area: Implications for herpetofauna habitat management and restoration.

Science.gov (United States)

Markle, Chantel E; Chow-Fraser, Gillian; Chow-Fraser, Patricia

2018-01-01

Point Pelee National Park, located at the southern-most tip of Canada's mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931-2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.

A basic strategy for financing long term care.

Science.gov (United States)

Greenberg, J A; Leutz, W N

1984-02-01

As pressure mounts to contain Medicaid long term care spending, short-range "quick fixes" must be avoided. Three such false solutions in particular have shortcomings that may actually exacerbate long term care's financial dilemma because they are based on inadequate definitions of the problem. Two of these proposals--legislation to broaden family responsibility toward institutionalized elders on Medicaid and expanded state power to put liens on such elders' real property--err by trying to mandate "caring" and are predicated on a misunderstanding of the "spend-down" problem. The other proposal--to provide tax incentives to family members who care for elders--requires a large administrative apparatus, assumes an elasticity of supply that may not exist, and could disrupt the "gift relationship" on which family exchanges are often based. What is needed is a strategy with short term, intermediate, and long term objectives that move toward an insurance approach. The short term plan should lay the groundwork for intermediate strategy and control costs by changing rate-setting methods and putting limits on facility construction. The intermediate plan should change the problem's definition from one of merely controlling Medicaid long term care expenditures to one of efficiently managing state resources for the elderly through the development of state financing and local delivery systems that target older persons in greatest need. An effective means of doing this is through the creation of social/HMOs, which have five key features: integration of service responsibility and authority; flexibility in organizational design; balanced clientele; pooled prepaid funding; and financial risk for the provider organization. Finally, the long term strategy should transfer much of the long term care financial burden from individuals and state Medicaid agencies to insurance mechanisms. Many individuals would thus avoid impoverishment caused by health care spending and Medicaid would

Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

Science.gov (United States)

Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

2011-01-01

This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

[Long-term psychiatric hospitalizations].

Science.gov (United States)

Plancke, L; Amariei, A

2017-02-01

Long-term hospitalizations in psychiatry raise the question of desocialisation of the patients and the inherent costs. Individual indicators were extracted from a medical administrative database containing full-time psychiatric hospitalizations for the period 2011-2013 of people over 16 years old living in the French region of Nord-Pas-de-Calais. We calculated the proportion of people who had experienced a hospitalization with a duration of 292 days or more during the study period. A bivariate analysis was conducted, then ecological data (level of health-care offer, the deprivation index and the size of the municipalities of residence) were included into a multilevel regression model in order to identify the factors significantly related to variability of long-term hospitalization rates. Among hospitalized individuals in psychiatry, 2.6% had had at least one hospitalization of 292 days or more during the observation period; the number of days in long-term hospitalization represented 22.5% of the total of days of full-time hospitalization in psychiatry. The bivariate analysis revealed that seniority in the psychiatric system was strongly correlated with long hospitalization rates. In the multivariate analysis, the individual indicators the most related to an increased risk of long-term hospitalization were: total lack of autonomy (OR=9.0; 95% CI: 6.7-12.2; P<001); diagnoses of psychological development disorders (OR=9.7; CI95%: 4.5-20.6; P<.001); mental retardation (OR=4.5; CI95%: 2.5-8.2; P<.001): schizophrenia (OR=3.0; CI95%: 1.7-5.2; P<.001); compulsory hospitalization (OR=1.7; CI95%: 1.4-2.1; P<.001); having experienced therapeutic isolation (OR=1.8; CI95%: 1.5-2.1; P<.001). Variations of long-term hospitalization rates depending on the type of establishment were very high, but the density of hospital beds or intensity of ambulatory activity services were not significantly linked to long-term hospitalization. The inhabitants of small urban units had

Join the Revolution: How Montessori for Aging and Dementia can Change Long-Term Care Culture.

Science.gov (United States)

Bourgeois, Michelle S; Brush, Jennifer; Elliot, Gail; Kelly, Anne

2015-08-01

Efforts to improve the quality of life of persons with dementia in long-term care through the implementation of various approaches to person-centered care have been underway for the past two decades. Studies have yielded conflicting reports evaluating the evidence for these approaches. The purpose of this article is to outline the findings of several systematic reviews of this literature, highlighting the areas of improvement needs, and to describe a new person-centered care model, DementiAbility Methods: The Montessori Way. This model focuses on the abilities, needs, interests, and strengths of the person and creating worthwhile and meaningful roles, routines, and activities for the person within a supportive physical environment. This is accomplished through gaining the commitment of the facility's leaders, training staff, and monitoring program implementation. The potential for a culture change in long-term care environments is dependent on the development and rigorous evaluation of person-centered care approaches. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Healthful dietary patterns and long-term weight change among women with a history of gestational diabetes mellitus.

Science.gov (United States)

Tobias, D K; Zhang, C; Chavarro, J; Olsen, S; Bao, W; Bjerregaard, A A; Fung, T T; Manson, J E; Hu, F B

2016-11-01

Diet represents a key strategy for the prevention of obesity and type 2 diabetes among women with a history of gestational diabetes mellitus (GDM), although effective dietary patterns to prevent weight gain in the long term are largely unknown. We sought to evaluate whether improvement in overall diet quality is associated with less long-term weight gain among high-risk women with prior GDM. Women with a history of GDM (N=3397) were followed from 1991 to 2011, or until diagnosis of type 2 diabetes or other chronic disease. Usual diet was assessed via food frequency questionnaire every 4 years from which we calculated the Alternative Healthy Eating Index (aHEI-2010), Alternate Mediterranean Diet (AMED) and Dietary Approaches to Stop Hypertension (DASH) dietary pattern scores. Weight, lifestyle and health-related outcomes were self-reported every 2 years. We estimated the change in dietary score with change in body weight using linear regression models adjusting for age, baseline body mass index (BMI), baseline and simultaneous change in physical activity and smoking status and other risk factors. Women were followed up to 20 years, gaining an average 1.9 kg (s.d.=7.0) per 4-year period. Women in the highest quintile (Q5) of diet change (most improvement in quality) gained significantly less weight per 4-year period than the lowest quintile (Q1; decrease in quality), independent of other risk factors (4-year weight change, aHEI-2010: Q5=1.30 kg vs Q1=3.27 kg; AMED: Q5=0.94 kg vs Q1=2.56 kg, DASH: Q5=0.64 kg vs Q1=2.75 kg). Significant effect modification by BMI (p-interactions diet quality was associated with less weight gain, independent of other lifestyle factors. Post-partum recommendations on diet quality may provide one strategy to prevent long-term weight gain in this high-risk group.

Long-term changes in sea surface temperatures

International Nuclear Information System (INIS)

Parker, D.E.

1994-01-01

Historical observations of sea surface temperature since 1856 have been improved by applying corrections to compensate for the predominant use of uninsulated or partly insulated buckets until the Second World War. There are large gaps in coverage in the late nineteenth century and around the two world wars, but a range of statistical techniques suggest that these gaps do not severely prejudice estimates of global and regional climatic change. Nonetheless, to improve the analysis on smaller scales, many unused historical data are to be digitized and incorporated. For recent years, satellite-based sea surface temperatures have improved the coverage, after adjustments for their biases relative to in situ data. An initial version of a nominally globally complete sea ice and interpolated sea surface temperature data set, beginning in 1871, has been created for use in numerical simulations of recent climate. Long time series of corrected regional, hemispheric, and global sea surface temperatures are mostly consistent with corresponding night marine air temperature series, and confirm the regionally specific climatic changes portrayed in the Scientific Assessments of the intergovernmental Panel on Climate Change. The observations also show an El Nino-like oscillation on bidecadal and longer time scales

Soil and vegetation surveillance

Energy Technology Data Exchange (ETDEWEB)

Antonio, E.J.

1995-06-01

Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

Long-term variability of dust-storms in Iceland

Science.gov (United States)

Dagsson-Waldhauserová, Pavla; Ólafsson, Haraldur; Arnalds, Ólafur

2013-04-01

Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland are volcanic sandy deserts. Natural emissions from these sources influenced by strong winds affect not only regional air quality in Iceland ("Reykjavik haze") but dust particles are transported over the Atlantic ocean and Arctic Ocean > 1000 km at times. The study places Icelandic dust production area into international perspective, present long term frequency of dust storm events in NE Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in NE Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the NE erosion area, indicating extreme dust plume activity and erosion within the NE deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and aeolian transport during dust/volcanic ash storms in Iceland which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust is not only a substantial source for regional air pollution, but may be considered to contribute to the Arctic haze phenomena and Arctic air pollution.

The effect of communication change on long-term reductions in child exposure to conflict: impact of the promoting strong African American families (ProSAAF) program.

Science.gov (United States)

Beach, Steven R H; Barton, Allen W; Lei, Man Kit; Brody, Gene H; Kogan, Steven M; Hurt, Tera R; Fincham, Frank D; Stanley, Scott M

2014-12-01

African American couples (n = 331) with children, 89% of whom were married, were assigned to either (a) a culturally sensitive couple- and parenting-enhancement program (ProSAAF) or (b) an information-only control condition in which couples received self-help materials. Husbands averaged 41 years of age and wives averaged 39 years. We found significant effects of program participation in the short term on couple communication, which was targeted by the intervention, as well as over the long term, on self-reported arguing in front of children. Long-term parenting outcomes were fully mediated by changes in communication for wives, but not for husbands. For husbands, positive change depended on amount of wife reported change. We conclude that wives' changes in communication from baseline to posttest may be more pivotal for the couples' long-term experience of decreased arguing in front of children than are husbands' changes, with wives' changes leading to changes in both partners' reports of arguments in front of children. © 2014 Family Process Institute.

Catastrophic shifts in vegetation-soil systems may unfold rapidly or slowly independent of the rate of change in the system driver

Science.gov (United States)

Karssenberg, Derek; Bierkens, Marc

2014-05-01

Complex systems may switch between contrasting stable states under gradual change of a driver. Such critical transitions often result in considerable long-term damage because strong hysteresis impedes reversion, and the transition becomes catastrophic. Critical transitions largely reduce our capability of forecasting future system states because it is hard to predict the timing of their occurrence [2]. Moreover, for many systems it is unknown how rapidly the critical transition unfolds when the tipping point has been reached. The rate of change during collapse, however, is important information because it determines the time available to take action to reverse a shift [1]. In this study we explore the rate of change during the degradation of a vegetation-soil system on a hillslope from a state with considerable vegetation cover and large soil depths, to a state with sparse vegetation and a bare rock or negligible soil depths. Using a distributed, stochastic model coupling hydrology, vegetation, weathering and water erosion, we derive two differential equations describing the vegetation and the soil system, and their interaction. Two stable states - vegetated and bare - are identified by means of analytical investigation, and it is shown that the change between these two states is a critical transition as indicated by hysteresis. Surprisingly, when the tipping point is reached under a very slow increase of grazing pressure, the transition between the vegetated and the bare state can either unfold rapidly, over a few years, or gradually, occurring over decennia up to millennia. These differences in the rate of change during the transient state are explained by differences in bedrock weathering rates. This finding emphasizes the considerable uncertainty associated with forecasting catastrophic shifts in ecosystems, which is due to both difficulties in forecasting the timing of the tipping point and the rate of change when the transition unfolds. References [1] Hughes

Long-term change in the megabenthos of the Porcupine Abyssal Plain (NE Atlantic)

Science.gov (United States)

Billett, D. S. M.; Bett, B. J.; Rice, A. L.; Thurston, M. H.; Galéron, J.; Sibuet, M.; Wolff, G. A.

A radical change in the abundance of invertebrate megafauna on the Porcupine Abyssal Plain is reported over a period of 10 years (1989-1999). Actiniarians, annelids, pycnogonids, tunicates, ophiuroids and holothurians increased significantly in abundance. However, there was no significant change in wet weight biomass. Two holothurian species, Amperima rosea and Ellipinion molle, increased in abundance by more than two orders of magnitude. Samples from the Porcupine Abyssal Plain over a longer period (1977-1999) show that prior to 1996 these holothurian species were always a minor component of the megafauna. From 1996 to 1999 A. rosea was abundant over a wide area of the Porcupine Abyssal Plain indicating that the phenomenon was not a localised event. Several dominant holothurian species show a distinct trend in decreasing body size over the study period. The changes in megafauna abundance may be related to environmental forcing (food supply) rather than to localised stochastic population variations. Inter-annual variability and long-term trends in organic matter supply to the seabed may be responsible for the observed changes in abundance, species dominance and size distributions.

Emulation of long-term changes in global climate: application to the late Pliocene and future

Directory of Open Access Journals (Sweden)

N. S. Lord

2017-11-01

Full Text Available Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs, long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term continuous projections of climate evolution based on the output from GCMs, via the use of a statistical emulator. The emulator is calibrated using ensembles of GCM simulations, which have varying orbital configurations and atmospheric CO2 concentrations and enables a variety of investigations of long-term climate change to be conducted, which would not be possible with other modelling techniques on the same temporal and spatial scales. To illustrate the potential applications, we apply the emulator to the late Pliocene (by modelling surface air temperature – SAT, comparing its results with palaeo-proxy data for a number of global sites, and to the next 200 kyr (thousand years (by modelling SAT and precipitation. A range of CO2 scenarios are prescribed for each period. During the late Pliocene, we find that emulated SAT varies on an approximately precessional timescale, with evidence of increased obliquity response at times. A comparison of atmospheric CO2 concentration for this period, estimated using the proxy sea surface temperature (SST data from different sites and emulator results, finds that relatively similar CO2 concentrations are estimated based on sites at lower latitudes, whereas higher-latitude sites show larger discrepancies. In our second illustrative application, spanning the next

Long-term contracts for European gas supply - an empirical analysis of the changing nature of pipeline and LNG-contracts

International Nuclear Information System (INIS)

Neumann, Anne

2005-01-01

As the structure of the European natural gas market is evolving towards more competition and more diverse market structures than before, the nature of the long-term contracts for European natural gas supply is also undergoing change. Experience from other liberalization processes, such as in the U.S. or the UK, suggests that the importance of long-term contracts diminishes over time, but that they remain an important element of supply. In Europe long-term contracts are still considered as a firm basis for investment and financing of capital-intensive infrastructure with a high degree of asset and relationship-specificity. Literature on institutional economics also suggests that long-term contracts act as a device to overcome the ''hold-up'' problem of relationship-specific investments in infrastructure (Klein, Crawford, and Alchian, 1987; Williamson, 1975, 1985). On the other hand, Hartley and Brito (2002) show that more flexible markets also imply a lower degree of asset specificity, thus requiring less fixed contracts. This paper explores the changing nature of long-term contracts for European natural gas supply, with a particular focus on differences between contracts for pipeline gas and liquefied natural gas (LNG). Traditionally, Europe relied on very long-term contracts for pipeline gas (Russia, Norway, Algeria). More recently, increasing LNG supplies are contemplated as a more flexible source of natural gas: The international LNG market is becoming more flexible, LNG can be sourced from a variety of sellers, and the cost of LNG supplies and infrastructure is coming down rapidly (Jensen, 2004). Thus, the evaluation of investing in LNG infrastructure (and the so bought flexibility and possibility of arbitraging profits) may be higher than committing to fixed/predetermined flows of pipeline gas. We ask whether this is reflected in the observed contracts. The paper is based on standard contract theory (Bolton and Dewatripont, 2005). We apply a microeconomic

PKMζ inhibition prevents the metaplastic change induced by conditioned taste aversion on insular cortex long-term potentiation in vivo.

Science.gov (United States)

Ángeles-Durán, Sandybel; Ramos-Languren, Laura E; Escobar, Martha L

2012-01-01

The activity history of a given neuron or pathway has been suggested to influence its future responses to synaptic inputs. In particular, training in several learning tasks produces a metaplastic change, that is, a change in the ability to induce subsequent synaptic plasticity. Experimental evidence shows that the maintenance of long term memory and long-term potentiation (LTP) requires the persistent action of the atypical protein kinase Cisoform, protein kinase M ζ (PKM ζ ). Recent work has demonstrated that the inactivation of PKM ζ in the insular cortex (IC) abolishes conditioned taste aversion (CTA) long term memory. Our previous studies in the IC have demonstrated that the induction of LTP in the basolateral amygdaloid nucleus (Bla)-IC projection previous to CTA training enhances the retention of this task. Moreover, recently, we have observed that CTA training blocks the subsequent induction of LTP in the Bla-IC projection. The aim of the present study was to investigate the participation of PKM ζon the CTA-dependent modification of the ability to induce subsequent LTP in the Bla-IC projection in vivo . Thus, we have delivered high-frequency stimulation in the Bla-IC projection in order to induce in vivo IC-LTP in the rats that underwent or did not have an impairment of CTA retention due to the intracortical administration of the selective PKM ζ pseudosubstrate inhibitory peptide, ZIP. Our results show that the microinfusion of ZIP into the IC of the behaving rats impairs long-term memory of CTA and prevents its effects on IC-LTP. These results indicate that PKM ζ is a key component of the cellular mechanisms necessary for the persistence of lasting memory traces as well as for those underlying metaplastic changes in neocortex, contributing to the persistence of aversive memories.

Diverse perspectives on governance on the very long term. Biodiversity, climatic change, CO2 storage, radioactive wastes, space wastes

International Nuclear Information System (INIS)

Boeuf, Gilles; Gouyon, Pierre Henry; Rollinger, Francois; Besnus, Francois; Heriard Dubreuil, Gilles; Dahan, Amy; Alby, Fernand; Arnould, Jacques; Fabriol, Hubert; Hoummady, Moussa; Demarcq, Francois; Farret, Regis; Hubert, Philippe; Weber, Jacques; Charton, Patrick; Boissier, Fabrice; Lopez, Mirelle; Devisse, Jean-Jacques; Mathy, Sandrine; Hourcade, Jean-Charles; Le Roux, Xavier; Bourcier, Danielle; Roure, Francoise; Henry, Claude; Bartet, Jean Hughes; Calame, Mathieu; Biteau, Benoit; Kastler, Guy; Ducret, Pierre; Berest, Pierre; Charron, Sylvie; Clin, Francois; Gadbois, Serge; Gueritte, Michel; Heriard-Dubreuil, Bertrand; Laville, Bettina; Marie, Michel; Marignac, Yves; Ollagnon, Henry; Pelegrin, Flora; Roure, Francoise; Rouyer, Michel; Schellenberger, Thomas; Toussaint, Jean-Francois

2013-03-01

This bibliographical note contains the program of a workshop and a presentation of a book based on the contributions to this workshop proposed by experts, representatives of institutional bodies and associations, or local representatives. This workshop addressed the issue of the governance on the very long term with respect to the management of resources such as climate, geology, biodiversity or space. How to make a possible usage of these resources while ensuring their protection and durability? What are the solutions or new challenges are raising these usages on the very long term? The first part addresses the main challenges and ethical issues for governance on the very long term for each of the examined topics: biodiversity, climatic change, CO 2 storage, radioactive waste storage, and space debris). The next parts propose contributions from different origins and disciplines, present relevant data, and report evidences

Hyperspectral remote sensing and long term monitoring reveal watershed-estuary ecosystem interactions

Science.gov (United States)

Hestir, E. L.; Schoellhamer, D. H.; Santos, M. J.; Greenberg, J. A.; Morgan-King, T.; Khanna, S.; Ustin, S.

2016-02-01

Estuarine ecosystems and their biogeochemical processes are extremely vulnerable to climate and environmental changes, and are threatened by sea level rise and upstream activities such as land use/land cover and hydrological changes. Despite the recognized threat to estuaries, most aspects of how change will affect estuaries are not well understood due to the poorly resolved understanding of the complex physical, chemical and biological processes and their interactions in estuarine systems. Remote sensing technologies such as high spectral resolution optical systems enable measurements of key environmental parameters needed to establish baseline conditions and improve modeling efforts. The San Francisco Bay-Delta is a highly modified estuary system in a state of ecological crisis due to the numerous threats to its sustainability. In this study, we used a combination of hyperspectral remote sensing and long-term in situ monitoring records to investigate how water clarity has been responding to extreme climatic events, anthropogenic watershed disturbances, and submerged aquatic vegetation (SAV) invasions. From the long-term turbidity monitoring record, we found that water clarity underwent significant increasing step changes associated with sediment depletion and El Nino-extreme run-off events. Hyperspectral remote sensing data revealed that invasive submerged aquatic pant species have facultative C3 and C4-like photosynthetic pathways that give them a competitive advantage under the changing water clarity conditions of the Bay-Delta system. We postulate that this adaptation facilitated the rapid expansion of SAV following the significant step changes in increasing water clarity caused by watershed disturbances and the 1982-1983 El Nino events. Using SAV maps from hyperspectral remote sensing, we estimate that SAV-water clarity feedbacks were responsible for 20-70% of the increasing water clarity trend in the Bay-Delta. Ongoing and future developments in airborne and

Monitoring of vegetation dynamics and assessing vegetation response to drought in the Iberian Peninsula

Energy Technology Data Exchange (ETDEWEB)

Garcia-Haro, F. J.; Moreno, A.; Perez-Hoyos, A.; Gilabert, M. A.; Melia, J.; Belda, F.; Poquet, D.; Martinez, B.; Verger, A.

2009-07-01

Monitoring the vegetation activity over long time-scales is necessary to discern ecosystem response to climate variability. Spatial and temporally consistent estimates of the biophysical variables such as fractional vegetation cover (FVC) and leaf area index (LAI) have been obtained in the context of DULCINEA Project. We used long-term monthly climate statistics to build simple climatic indices (SPI, moisture index) at different time scales. From these indices, we estimated that the climatic disturbances affected both the growing season and the total amount of vegetation. This implies that the anomaly of vegetation cover is a good indicator of moisture condition and can be an important data source when used for detecting an monitoring drought in the Iberian Peninsula. The impact of climate variability on the vegetation dynamics has shown not to be the same for every region. We concluded that the relationships between vegetation anomaly and moisture availability are significant for the arid and semiarid areas. (Author) 6 refs.

Monitoring of vegetation dynamics and assessing vegetation response to drought in the Iberian Peninsula

International Nuclear Information System (INIS)

Garcia-Haro, F. J.; Moreno, A.; Perez-Hoyos, A.; Gilabert, M. A.; Melia, J.; Belda, F.; Poquet, D.; Martinez, B.; Verger, A.

2009-01-01

Monitoring the vegetation activity over long time-scales is necessary to discern ecosystem response to climate variability. Spatial and temporally consistent estimates of the biophysical variables such as fractional vegetation cover (FVC) and leaf area index (LAI) have been obtained in the context of DULCINEA Project. We used long-term monthly climate statistics to build simple climatic indices (SPI, moisture index) at different time scales. From these indices, we estimated that the climatic disturbances affected both the growing season and the total amount of vegetation. This implies that the anomaly of vegetation cover is a good indicator of moisture condition and can be an important data source when used for detecting an monitoring drought in the Iberian Peninsula. The impact of climate variability on the vegetation dynamics has shown not to be the same for every region. We concluded that the relationships between vegetation anomaly and moisture availability are significant for the arid and semiarid areas. (Author) 6 refs.

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.

Science.gov (United States)

Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K

2014-09-15

In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

LONG-TERM OUTCOME IN PEDIATRIC TRICHOTILLOMANIA.

Science.gov (United States)

Schumer, Maya C; Panza, Kaitlyn E; Mulqueen, Jilian M; Jakubovski, Ewgeni; Bloch, Michael H

2015-10-01

To examine long-term outcome in children with trichotillomania. We conducted follow-up clinical assessments an average of 2.8 ± 0.8 years after baseline evaluation in 30 of 39 children who previously participated in a randomized, double-blind, placebo-controlled trial of N-acetylcysteine (NAC) for pediatric trichotillomania. Our primary outcome was change in hairpulling severity on the Massachusetts General Hospital Hairpulling Hospital Hairpulling Scale (MGH-HPS) between the end of the acute phase and follow-up evaluation. We also obtained secondary measures examining styles of hairpulling, comorbid anxiety and depressive symptoms, as well as continued treatment utilization. We examined both correlates and predictors of outcome (change in MGH-HPS score) using linear regression. None of the participants continued to take NAC at the time of follow-up assessment. No significant changes in hairpulling severity were reported over the follow-up period. Subjects reported significantly increased anxiety and depressive symptoms but improvement in automatic pulling symptoms. Increased hairpulling symptoms during the follow-up period were associated with increased depression and anxiety symptoms and increased focused pulling. Older age and greater focused pulling at baseline assessment were associated with poor long-term prognosis. Our findings suggest that few children with trichotillomania experience a significant improvement in trichotillomania symptoms if behavioral treatments are inaccessible or have failed to produce adequate symptom relief. Our findings also confirm results of previous cross-sectional studies that suggest an increased risk of depression and anxiety symptoms with age in pediatric trichotillomania. Increased focused pulling and older age among children with trichotillomania symptoms may be associated with poorer long-term prognosis. © 2015 Wiley Periodicals, Inc.

Minor effects of long-term ozone exposure on boreal peatland species Eriophorum vaginatum and Sphagnum papillosum

DEFF Research Database (Denmark)

Mörsky, SK; Haapala, JK; Rinnan, Riikka

2011-01-01

The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded...

Long-term accessibility of e-books: challenges, obstacles, responsibilities

Directory of Open Access Journals (Sweden)

Maja Krtalić

2015-07-01

Full Text Available The traditional life cycle of books has gone through many changes in the digital environment - enough to start questioning the effects of such changes on the process of creating, publishing, distributing, reading and preserving books. This paper focuses on issues concerning the preservation and archiving of published authors’ works in the digital environment for the purpose of their long-term accessibility. The aim of this paper is to give an overview of relevant legal, technical, societal and organisational issues from which challenges, obstacles and responsibilities in ensuring long-term accessibility of e-books arise. Issues related to authorship, editions, changes in content, copyright and digital rights management, selection criteria for preservation, and preservation responsibility will be discussed, specifically focusing on libraries’ and publishers’ roles in this process. The paper is based on a literature review and content analysis aiming to answer two basic research questions: What specific characteristics of e-books influence their preservation possibilities? Who is responsible for long-term accessibility of e-books?

Vegetation pattern formation in semiarid systems induced by long-range competition in the absence of facilitation mechanisms.

Science.gov (United States)

Martinez-Garcia, Ricardo; Calabrese, Justin M.; Hernandez-Garcia, Emilio; Lopez, Cristobal

2014-05-01

Regular patterns and spatial organization of vegetation have been observed in many arid and semiarid ecosystems worldwide, covering a diverse range of plant taxa and soil types. A key common ingredient in these systems is that plant growth is severely limited by water availability, and thus plants likely compete strongly for water. The study of such patterns is especially interesting because their features may reveal much about the underlying physical and biological processes that generated them in addition to giving information on the characteristics of the ecosystem. It is possible, for instance, to infer their resilience against anthropogenic disturbances or climatic changes that could cause abrupt shifts in the system and lead it to a desert state. Therefore much research has focused on identifying the underlying mechanisms that can produce spatial patterning in water-limited systems (Klausmeier, 1999). They are believed to arise from the interplay between long-range competition and facilitation processes acting at smaller distances (Borgogno et al., 2009). This combination of mechanisms is justified by arguing that water percolates more readily through the soil in vegetated areas (short range), and that plants compete for water resources over greater distances via long lateral roots (long range). However, recent studies have shown that even in the limit of local facilitation patterns may still appear (Martinez-Garcia et al., 2013). In this work (Martinez-Garcia et al., 2013b), we show that, under rather general conditions, long-range competition alone is the minimal ingredient to shape gapped and stripped vegetation patterns typical of models that also account for facilitation in addition to competition. To this end we propose a simple, general model for the dynamics of vegetation, which includes only long-range competition between plants. Competition is introduced through a nonlocal term, where the kernel function quantifies the intensity of the interaction

A model integrating longshore and cross-shore processes for predicting long-term shoreline response to climate change

Science.gov (United States)

Vitousek, Sean; Barnard, Patrick; Limber, Patrick W.; Erikson, Li; Cole, Blake

2017-01-01

We present a shoreline change model for coastal hazard assessment and management planning. The model, CoSMoS-COAST (Coastal One-line Assimilated Simulation Tool), is a transect-based, one-line model that predicts short-term and long-term shoreline response to climate change in the 21st century. The proposed model represents a novel, modular synthesis of process-based models of coastline evolution due to longshore and cross-shore transport by waves and sea-level rise. Additionally, the model uses an extended Kalman filter for data assimilation of historical shoreline positions to improve estimates of model parameters and thereby improve confidence in long-term predictions. We apply CoSMoS-COAST to simulate sandy shoreline evolution along 500 km of coastline in Southern California, which hosts complex mixtures of beach settings variably backed by dunes, bluffs, cliffs, estuaries, river mouths, and urban infrastructure, providing applicability of the model to virtually any coastal setting. Aided by data assimilation, the model is able to reproduce the observed signal of seasonal shoreline change for the hindcast period of 1995-2010, showing excellent agreement between modeled and observed beach states. The skill of the model during the hindcast period improves confidence in the model's predictive capability when applied to the forecast period (2010-2100) driven by GCM-projected wave and sea-level conditions. Predictions of shoreline change with limited human intervention indicate that 31% to 67% of Southern California beaches may become completely eroded by 2100 under sea-level rise scenarios of 0.93 to 2.0 m.

Long-term climate change assessment study plan for the Hanford Site permanent isolation Barrier Development Program

International Nuclear Information System (INIS)

Petersen, K.L.; Chatters, J.C.; Waugh, W.J.

1992-07-01

The Hanford Site Permanent Isolation Barrier Development Program (Barrier Development Program) was organized to develop the technology needed to provide an in-place disposal capability for the Hanford Site (Adams and Wing 1986; Wig and Gee 1990). The goal of the Barrier Development Program is to provide defensible evidence that final barrier design(s) will adequately control water infiltration; plant and animal intrusion; and wind and water erosion for a minimum of 1,000 yr and isolate wastes from the accessible environment and warm inadvertent human intruders using markers. This document describes the long-term climate change studies planned to support the Barrier Development Program. The plan outlines a multi-year and multi-discipline approach to assess long-term climate change issues and to help optimize the design of the permanent isolation barriers. A multi-disciplinary approach to climatic data acquisition will be responsible for obtaining needed information for concurrent barrier tasks and for developing a local climate forecast model. This model will couple past climate patterns with models of regional and global climate drivers to provide bounding conditions for barrier performance assessment analyses

A prospective cohort study of long-term cognitive changes in older Medicare beneficiaries.

Science.gov (United States)

Wolinsky, Fredric D; Bentler, Suzanne E; Hockenberry, Jason; Jones, Michael P; Weigel, Paula A; Kaskie, Brian; Wallace, Robert B

2011-09-20

Promoting cognitive health and preventing its decline are longstanding public health goals, but long-term changes in cognitive function are not well-documented. Therefore, we first examined long-term changes in cognitive function among older Medicare beneficiaries in the Survey on Assets and Health Dynamics among the Oldest Old (AHEAD), and then we identified the risk factors associated with those changes in cognitive function. We conducted a secondary analysis of a prospective, population-based cohort using baseline (1993-1994) interview data linked to 1993-2007 Medicare claims to examine cognitive function at the final follow-up interview which occurred between 1995-1996 and 2006-2007. Besides traditional risk factors (i.e., aging, age, race, and education) and adjustment for baseline cognitive function, we considered the reason for censoring (entrance into managed care or death), and post-baseline continuity of care and major health shocks (hospital episodes). Residual change score multiple linear regression analysis was used to predict cognitive function at the final follow-up using data from telephone interviews among 3,021 to 4,251 (sample size varied by cognitive outcome) baseline community-dwelling self-respondents that were ≥ 70 years old, not in managed Medicare, and had at least one follow-up interview as self-respondents. Cognitive function was assessed using the 7-item Telephone Interview for Cognitive Status (TICS-7; general mental status), and the 10-item immediate and delayed (episodic memory) word recall tests. Mean changes in the number of correct responses on the TICS-7, and 10-item immediate and delayed word recall tests were -0.33, -0.75, and -0.78, with 43.6%, 54.9%, and 52.3% declining and 25.4%, 20.8%, and 22.9% unchanged. The main and most consistent risks for declining cognitive function were the baseline values of cognitive function (reflecting substantial regression to the mean), aging (a strong linear pattern of increased decline

Effects of landscape gradients on wetland vegetation communities: information for large-scale restoration

Science.gov (United States)

Zweig, Christa L.; Kitchens, Wiley M.

2008-01-01

Projects of the scope of the restoration of the Florida Everglades require substantial information regarding ecological mechanisms, and these are often poorly understood. We provide critical base knowledge for Everglades restoration by characterizing the existing vegetation communities of an Everglades remnant, describing how present and historic hydrology affect wetland vegetation community composition, and documenting change from communities described in previous studies. Vegetation biomass samples were collected along transects across Water Conservation Area 3A South (3AS). Ten community types were present between November 2002 and 2005. Separate analyses for key a priori groups (slough, wet prairie, and sawgrass) provided detailed conclusions about effects of historic hydrology on the vegetation of 3AS. Communities were affected by hydrologic variables LIP to four years previous to the sample. We identified wet prairie/slough species such as Eleocharis spp. and Nymphaea odorata as short-term sentinel species of community change. Sawgrass and N. odorata should be monitored for long-term change. Comparisons to preceding studies indicated that many of the communities of previous times, when conditions were drier, no longer exist in our study area and have been replaced by deeper water community types.

A long-term vegetation history of the Mojave-Colorado Desert ecotone at Joshua Tree National Park

Science.gov (United States)

Holmgren, Camille A.; Betancourt, Julio L.; Rylander, Kate A.

2010-01-01

Thirty-eight dated packrat middens were collected from upper desert (930–1357 m) elevations within Joshua Tree National Park near the ecotone between the Mojave Desert and Colorado Desert, providing a 30 ka record of vegetation change with remarkably even coverage for the last 15 ka. This record indicates that vegetation was relatively stable, which may reflect the lack of invasion by extralocal species during the late glacial and the early establishment and persistence of many desert scrub elements. Many of the species found in the modern vegetation assemblages were present by the early Holocene, as indicated by increasing Sørenson's Similarity Index values. C4 grasses and summer-flowering annuals arrived later at Joshua Tree National Park in the early Holocene, suggesting a delayed onset of warm-season monsoonal precipitation compared to other Sonoran Desert and Chihuahuan Desert localities to the east, where summer rains and C4 grasses persisted through the last glacial–interglacial cycle. This would suggest that contemporary flow of monsoonal moisture into eastern California is secondary to the core processes of the North American Monsoon, which remained intact throughout the late Quaternary. In the Holocene, northward displacement of the jet stream, in both summer and winter, allowed migration of the subtropical ridge as far north as southern Idaho and the advection of monsoonal moisture both westward into eastern California and northward into the southern Great Basin and Colorado Plateau.

Preparing Landsat Image Time Series (LITS for Monitoring Changes in Vegetation Phenology in Queensland, Australia

Directory of Open Access Journals (Sweden)

Santosh Bhandari

2012-06-01

Full Text Available Time series of images are required to extract and separate information on vegetation change due to phenological cycles, inter-annual climatic variability, and long-term trends. While images from the Landsat Thematic Mapper (TM sensor have the spatial and spectral characteristics suited for mapping a range of vegetation structural and compositional properties, its 16-day revisit period combined with cloud cover problems and seasonally limited latitudinal range, limit the availability of images at intervals and durations suitable for time series analysis of vegetation in many parts of the world. Landsat Image Time Series (LITS is defined here as a sequence of Landsat TM images with observations from every 16 days for a five-year period, commencing on July 2003, for a Eucalyptus woodland area in Queensland, Australia. Synthetic Landsat TM images were created using the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM algorithm for all dates when images were either unavailable or too cloudy. This was done using cloud-free scenes and a MODIS Nadir BRDF Adjusted Reflectance (NBAR product. The ability of the LITS to measure attributes of vegetation phenology was examined by: (1 assessing the accuracy of predicted image-derived Foliage Projective Cover (FPC estimates using ground-measured values; and (2 comparing the LITS-generated normalized difference vegetation index (NDVI and MODIS NDVI (MOD13Q1 time series. The predicted image-derived FPC products (value ranges from 0 to 100% had an RMSE of 5.6. Comparison between vegetation phenology parameters estimated from LITS-generated NDVI and MODIS NDVI showed no significant difference in trend and less than 16 days (equal to the composite period of the MODIS data used difference in key seasonal parameters, including start and end of season in most of the cases. In comparison to similar published work, this paper tested the STARFM algorithm in a new (broadleaf forest environment and also

Monitoring riparian-vegetation composition and cover along the Colorado River downstream of Glen Canyon Dam, Arizona

Science.gov (United States)

Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel A.; Johnson, Taylor C.

2018-06-05

Vegetation in the riparian zone (the area immediately adjacent to streams, such as stream banks) along the Colorado River downstream of Glen Canyon Dam, Arizona, supports many ecosystem and societal functions. In both Glen Canyon and Grand Canyon, this ecosystem has changed over time in response to flow alterations, invasive species, and recreational use. Riparian-vegetation cover and composition are likely to continue to change as these pressures persist and new ones emerge. Because this system is a valuable resource that is known to change in response to flow regime and other disturbances, a long-term monitoring protocol has been designed with three primary objectives:Annually measure and summarize the status (composition and cover) of native and non-native vascular-plant species within the riparian zone of the Colorado River between Glen Canyon Dam and Lake Mead.At 5-year intervals, assess change in vegetation composition and cover in the riparian zone, as related to geomorphic setting and dam operations, particularly flow regime.Collect data in a manner that can be used by multiple stakeholders, particularly the basinwide monitoring program overseen by the National Park Service’s Northern Colorado Plateau Network Inventory and Monitoring program.A protocol for the long-term monitoring of riparian vegetation is described in detail and standard operating procedures are included herein for all tasks. Visual estimates of foliar and ground covers are collected in conjunction with environmental measurements to assess correlations of foliar cover with abiotic and flow variables. Sample quadrats are stratified by frequency of inundation, geomorphic feature, and by river segment to account for differences in vegetation type. Photographs of sites are also taken to illustrate qualitative characteristics of the site at the time of sampling. Procedures for field preparation, generating random samples, data collection, data management, collecting and managing unknown

The stability of vacuum phototriodes to varying light pulse loads and long term changes in response.

CERN Document Server

Hobson, Peter

2012-01-01

Mesh anode Vacuum Phototriodes (VPTs) are radiation resistant, single gain-stage photomultipliers which are designed to operate in a strong quasi-axial magnetic field. These VPTs are used in the endcap electromagnetic calorimeter of the CMS experiment at the CERN LHC to detect scintillation light from lead tungstate crystals. Short term dynamic response changes occur because of pulse rate variations during normal LHC operation cycles. Over the longer term the effect of increasing integrated charge taken from the photocathode causes an overall degradation of response. We have investigated these effects over time periods exceeding two years of simulated operation and discuss the implications for the long term performance of the VPTs in CMS.

Long-Term Symbolic Learning

National Research Council Canada - National Science Library

Kennedy, William G; Trafton, J. G

2007-01-01

What are the characteristics of long-term learning? We investigated the characteristics of long-term, symbolic learning using the Soar and ACT-R cognitive architectures running cognitive models of two simple tasks...

Pediatric polytrauma : Short-term and long-term outcomes

NARCIS (Netherlands)

vanderSluis, CK; Kingma, J; Eisma, WH; tenDuis, HJ

Objective: To assess the short-term and long-term outcomes of pediatric polytrauma patients and to analyze the extent to which short-term outcomes can predict long-term outcomes. Materials and Methods: Ail pediatric polytrauma patients (Injury Severity Score of greater than or equal to 16, less than

Long-term funding and faithfulness to the original goal

International Nuclear Information System (INIS)

Sjoegren, G.

1999-02-01

The study describes long-term funding in terms of faithfulness to the original goals of the foundations. After having examined 20 different Swedish foundations three main categories of problems have appeared. The main threats to the original goals of the foundations are juridical problems, economic problems and a changing society. Fraud and embezzlement are covered by the Act (1994:1220) Concerning Foundations, but the law does not prevent unfaithfulness to the original goal of the foundation in terms of permutation. If the foundation is a private-established foundation the board has to apply for a change of the original goal to the Swedish Judicial Board for Public Lands and Funds. If the State, a municipality or a community establishes the foundation the Government can change the goal without permission of any other authority. Economic problems often strike smaller funds established by private persons, but State-established funds can also be hit by economical problems. The economic problems presented in the text are high tax levels, bad investments and problems getting donations. Both small private and large State-established foundations sometimes have to change their original goals as a result of a changing society. The goal of the foundation can be out-of-date, be against the ideology of the government party or the demography might have changed. Examples from each category are given in the text. The study is made to facilitate a description in general terms of the prospects for the Swedish nuclear funds if a final decision can not be made in the time span of 100 or 200 years. Looking back on the changes in the judicial, economical and political arenas during the last 200 years, one realizes the impossibility to foresee the changes that will occur within the next 200 years. The author's conclusion, after examined 20 foundation, is that it is impossible to establish a perfect long-term fund as we can not foresee the long-term future

Long-term funding and faithfulness to the original goal

Energy Technology Data Exchange (ETDEWEB)

Sjoegren, G

1999-02-01

The study describes long-term funding in terms of faithfulness to the original goals of the foundations. After having examined 20 different Swedish foundations three main categories of problems have appeared. The main threats to the original goals of the foundations are juridical problems, economic problems and a changing society. Fraud and embezzlement are covered by the Act (1994:1220) Concerning Foundations, but the law does not prevent unfaithfulness to the original goal of the foundation in terms of permutation. If the foundation is a private-established foundation the board has to apply for a change of the original goal to the Swedish Judicial Board for Public Lands and Funds. If the State, a municipality or a community establishes the foundation the Government can change the goal without permission of any other authority. Economic problems often strike smaller funds established by private persons, but State-established funds can also be hit by economical problems. The economic problems presented in the text are high tax levels, bad investments and problems getting donations. Both small private and large State-established foundations sometimes have to change their original goals as a result of a changing society. The goal of the foundation can be out-of-date, be against the ideology of the government party or the demography might have changed. Examples from each category are given in the text. The study is made to facilitate a description in general terms of the prospects for the Swedish nuclear funds if a final decision can not be made in the time span of 100 or 200 years. Looking back on the changes in the judicial, economical and political arenas during the last 200 years, one realizes the impossibility to foresee the changes that will occur within the next 200 years. The author`s conclusion, after examined 20 foundation, is that it is impossible to establish a perfect long-term fund as we can not foresee the long-term future

An Untargeted Metabolomics Approach to Characterize Short-Term and Long-Term Metabolic Changes after Bariatric Surgery.

Directory of Open Access Journals (Sweden)

Sophie H Narath

Full Text Available Bariatric surgery is currently one of the most effective treatments for obesity and leads to significant weight reduction, improved cardiovascular risk factors and overall survival in treated patients. To date, most studies focused on short-term effects of bariatric surgery on the metabolic profile and found high variation in the individual responses to surgery. The aim of this study was to identify relevant metabolic changes not only shortly after bariatric surgery (Roux-en-Y gastric bypass but also up to one year after the intervention by using untargeted metabolomics. 132 serum samples taken from 44 patients before surgery, after hospital discharge (1-3 weeks after surgery and at a 1-year follow-up during a prospective study (NCT01271062 performed at two study centers (Austria and Switzerland. The samples included 24 patients with type 2 diabetes at baseline, thereof 9 with diabetes remission after one year. The samples were analyzed by using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS, HILIC-QExactive. Raw data was processed with XCMS and drift-corrected through quantile regression based on quality controls. 177 relevant metabolic features were selected through Random Forests and univariate testing and 36 metabolites were identified. Identified metabolites included trimethylamine-N-oxide, alanine, phenylalanine and indoxyl-sulfate which are known markers for cardiovascular risk. In addition we found a significant decrease in alanine after one year in the group of patients with diabetes remission relative to non-remission. Our analysis highlights the importance of assessing multiple points in time in subjects undergoing bariatric surgery to enable the identification of biomarkers for treatment response, cardiovascular benefit and diabetes remission. Key-findings include different trend pattern over time for various metabolites and demonstrated that short term changes should not necessarily be used to identify

Long-term correlated change between personality traits and perceived social support in middle adulthood.

Science.gov (United States)

Allemand, Mathias; Schaffhuser, Kathrin; Martin, Mike

2015-03-01

This study investigated long-term correlated change between personality traits and perceived social support in middle adulthood. Two measurement occasions with an 8-year time interval from the Interdisciplinary Longitudinal Study on Adult Development (ILSE) were used. The sample consisted of 346 middle-aged adults (46-50 years at T1). Four different types of perceived social support were assessed. Personality traits were assessed with the NEO-Five-Factor Inventory (NEO-FFI). Longitudinal measurement invariance (MI) was established for both measures. The mean rank-order stabilities were .79 and .62 for personality traits and for perceived social support, respectively. The results demonstrated a mean-level increase for neuroticism and a decrease for extraversion and significant change variances for all constructs. The results of latent change models showed significant initial level correlations and correlated changes between personality traits and social support, implying that changes in these constructs show commonality. The results can expand our current thinking about correlated change in personality. © 2015 by the Society for Personality and Social Psychology, Inc.

Effect of ecological factors on the zonation of wetland vegetation

Directory of Open Access Journals (Sweden)

Richard Hrivnák

2011-01-01

Full Text Available The influence of some ecological factors to aquatic and marsh vegetation was studied during 1998-2000. Three basic vegetation units (Caricetum buekii, Typhetum latifoliae and Ceratophylletum submersi and three transitional communities were defined in the belt transect, which was established along the moisture gradient. The content of available soil nutrients in individual vegetation types differed only in case of the Ceratophyllum submersum community, where a higher magnesium and nitrogen content accumulated due to specific environmental conditions. Water and marsh vegetation is usually characterised by a pronounced spatial and temporal dynamics. In the studied area, its zonation was dependent from the terrain morphology, and both depth and duration of floods. The fluctuation of ground and surface water table during a three-year period caused changes in the occurrence and cover of several species (e.g. Carex buekii, Typha latifolia, aquatic macrophytes. Pronounced changes in the cover of some species occurred even within a single vegetation season due to the long-term sink of water table below the ground surface.

A comparative study of ancient sedimentary DNA, pollen and macrofossils from permafrost sediments of northern Siberia reveals long-term vegetational stability

DEFF Research Database (Denmark)

Jørgensen, Tina; Haile, James Seymour; Möller, Per

2012-01-01

and the determination of indicator species to describe environmental changes. Combining data from all three proxies reveals an area continually dominated by a mosaic vegetation of tundra-steppe, pioneer and wet-indicator plants. Such vegetational stability is unexpected, given the severe climate changes taking place...... in the Northern Hemisphere during this time, with changes in average annual temperatures of >22 °C. This may explain the abundance of ice-age mammals such as horse and bison in Taymyr Peninsula during the Pleistocene and why it acted as a refugium for the last mainland woolly mammoth. Our finding reveals...... the benefits of combining sedaDNA, pollen and macrofossil for palaeovegetational reconstruction and adds to the increasing evidence suggesting large areas of the Northern Hemisphere remained ecologically stable during the Late Pleistocene....

Determinants of vegetation distribution at continental scale. The contribution of natural and anthropogenic factors

DEFF Research Database (Denmark)

Greve, Michelle; Svenning, J.-C.; Lykke, Anne Mette

2011-01-01

It has long been debated what determines distribution of vegetation types, though this has rarely been tested at continental scale. We thus aimed to determine which vegetation types are most accurately predicted by natural environmental factors, and which of these factors best predict current veg...... was also assessed, and found to be of some importance for most vegetation types. We conclude that, in addition to including environmental variables in predicting vegetation distribution, it is essential that human impact be considered, also in future climate change scenarios....... vegetation distribution across Africa. Vegetation types were extracted from the Global Land Cover Map for the year 2000, and the distribution of vegetation types modelled in terms of climate, soil and topography. Annual precipitation was the best predictor of the distribution of all vegetation types...

Long-term phenology and variability of Southern Africa

CSIR Research Space (South Africa)

Steenkamp, K

2008-11-01

Full Text Available and classification of vegetation, (ii) studying the impact of climate change, and influence of rainfall variability (iii) monitoring Satellite-derived phenology and (iv) detecting changes in land use/ land cover. This study analyzed vegetation phenology across...

Becoming a normal guy: Men making sense of long-term bodily changes following bariatric surgery.

Science.gov (United States)

Groven, Karen Synne; Galdas, Paul; Solbrække, Kari Nyheim

2015-01-01

To date, research on bodily changes following bariatric surgery has focused predominantly on women, leaving the long-term experience of men relatively unexplored. In this paper, we draw on interviews with men who have undergone an irreversible gastric bypass procedure to explore their bodily changes more than 4 years post-surgery. We apply a phenomenological framework that draws on Leder's perspectives on the "disappearing" and "dys-appearing" body, combined with a gender-sensitive lens that draws on Connell's theory of hegemonic masculinity and Robertson's conceptions of embodied masculinity. Our principal finding was that the men negotiated their bodily changes following bariatric surgery in profoundly ambivalent ways. Although they enthusiastically praised the surgery for improving their health, self-esteem, and social functioning, they also emphasized their efforts to cope with post-surgical side effects and life-threatening complications. Our analysis elaborates on their efforts to adjust to and come to terms with these changes, focusing on episodes of hypoglycemia, severe pain and internal herniation, and the significance of physical activity and exercise. Our findings point to the need to acknowledge men's ways of making sense of profound and ongoing bodily changes following bariatric surgery and how these negotiations are closely intertwined with masculine ideals of embodiment and social value.

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects.

Science.gov (United States)

Nishiyama, Megumi; Kawaguchi, Jun

2014-11-01

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Global assessment of experimental climate warming on tundra vegetation: heterogeneity over space and time.

Science.gov (United States)

Elmendorf, Sarah C; Henry, Gregory H R; Hollister, Robert D; Björk, Robert G; Bjorkman, Anne D; Callaghan, Terry V; Collier, Laura Siegwart; Cooper, Elisabeth J; Cornelissen, Johannes H C; Day, Thomas A; Fosaa, Anna Maria; Gould, William A; Grétarsdóttir, Járngerður; Harte, John; Hermanutz, Luise; Hik, David S; Hofgaard, Annika; Jarrad, Frith; Jónsdóttir, Ingibjörg Svala; Keuper, Frida; Klanderud, Kari; Klein, Julia A; Koh, Saewan; Kudo, Gaku; Lang, Simone I; Loewen, Val; May, Jeremy L; Mercado, Joel; Michelsen, Anders; Molau, Ulf; Myers-Smith, Isla H; Oberbauer, Steven F; Pieper, Sara; Post, Eric; Rixen, Christian; Robinson, Clare H; Schmidt, Niels Martin; Shaver, Gaius R; Stenström, Anna; Tolvanen, Anne; Totland, Orjan; Troxler, Tiffany; Wahren, Carl-Henrik; Webber, Patrick J; Welker, Jeffery M; Wookey, Philip A

2012-02-01

Understanding the sensitivity of tundra vegetation to climate warming is critical to forecasting future biodiversity and vegetation feedbacks to climate. In situ warming experiments accelerate climate change on a small scale to forecast responses of local plant communities. Limitations of this approach include the apparent site-specificity of results and uncertainty about the power of short-term studies to anticipate longer term change. We address these issues with a synthesis of 61 experimental warming studies, of up to 20 years duration, in tundra sites worldwide. The response of plant groups to warming often differed with ambient summer temperature, soil moisture and experimental duration. Shrubs increased with warming only where ambient temperature was high, whereas graminoids increased primarily in the coldest study sites. Linear increases in effect size over time were frequently observed. There was little indication of saturating or accelerating effects, as would be predicted if negative or positive vegetation feedbacks were common. These results indicate that tundra vegetation exhibits strong regional variation in response to warming, and that in vulnerable regions, cumulative effects of long-term warming on tundra vegetation - and associated ecosystem consequences - have the potential to be much greater than we have observed to date. © 2011 Blackwell Publishing Ltd/CNRS.

The long-term hydrological effect of forest stands on the stability of slopes

Science.gov (United States)

Bogaard, T. A.; Meng, W.; van Beek, L. P. H.

2012-04-01

Forest is widely known to improve slope stability as a result of mechanical and hydrological effects. While the mechanics underlying the stabilizing process of root reinforcement are well understood and quantified, the influence of forest on the occurrence of critical hydrological conditions in terms of suction or pore pressure remains uncertain. Due to seasonal and inter-annual fluctuations, the stabilizing influence of evaporation and transpiration is difficult to isolate from the overall noise of the hydrological signal. More long-term effects of forest stands on soil development are highly variable and thus difficult to observe and quantify. Often these effects are ambivalent, having potentially a stabilizing or destabilizing influence on a slope under particular conditions (e.g., more structured soils leading to both rapid infiltration and drainage). Consequently, it can be postulated that forests will hydrologically influence the magnitude-frequency distribution of landsliding, not only at the stand level but also on a regional scale through the groundwater system. The overall aim of this research is to understand and quantify the stabilizing hydrological effect of forests on potentially unstable slopes. To this end, we focus on the changes in the magnitude-frequency distribution of landsliding that arise as a result of variations in evapotranspiration losses over the life cycle of stands. Temporal variations in evapotranspiration comprise first of all the interception that can account for an important amount of evaporation from a forest, and that changes with seasonal and annual variations in the interception capacity of the canopy and forest floor. Transpiration also represents an important loss that varies over the various growth stages of a forest stand. Based on a literature review of water consumption by tree species and water balance studies of forested catchments we defined the potential transpiration for different growth stages. This information we

Testing causes for long-term changes in carbon cycling and climate during the early Paleogene

Science.gov (United States)

Komar, N.; Zeebe, R. E.; Dickens, G. R.

2013-12-01

The late Paleocene to the early Eocene (˜58-52 Ma) was marked by significant changes in global climate and carbon cycling. Among the evidence for these changes, stable isotope records reveal a prominent decrease of δ13C and δ18O (in both surface and deep ocean), indicating a reorganization in the long-term global carbon cycle and a long-term warming trend (˜4°C), respectively. Concurrently, deep-sea carbonate records at several sites indicate a deepening of the calcite compensation depth (CCD). Here, we investigate possible causes (e.g., increased volcanic degassing, decreased net organic burial, and accelerated dissociation of gas hydrate) for these observations, but from a new perspective. The basic model employed is a modified version of GEOCARB III. However, we have coupled this well-known geochemical model to LOSCAR, a model that enables simulation of seawater carbonate chemistry, the CCD, and ocean δ13C. We have also added a gas hydrate capacitor that can account for the storage and release of methane from the seafloor over millions of years. We further consider accurate input data (e.g., δ13C of carbonate) on a currently accepted time scale that spans an interval much longer than the perturbation. Several different scenarios are investigated with the goal of consistency amongst inferred changes in temperature, the CCD, and surface ocean and deep ocean δ13C. The results strongly suggest that a decrease in net organic carbon burial drove carbon cycle changes during the late Paleocene and early Eocene, although an increase in volcanic activity might have contributed. Importantly, a drop in net organic carbon burial may represent increased oxidation of previously deposited organic carbon, such as stored in peat or gas hydrates. The model successfully recreates trends in Earth surface warming, as inferred from δ18O records, the CCD, and δ13C. At the moment, however, our coupled modeling effort cannot reproduce the magnitude of change in all these

Hair and Nail Changes During Long-term Therapy With Ibrutinib for Chronic Lymphocytic Leukemia.

Science.gov (United States)

Bitar, Carole; Farooqui, Mohammed Z H; Valdez, Janet; Saba, Nakhle S; Soto, Susan; Bray, Amanda; Marti, Gerald; Wiestner, Adrian; Cowen, Edward W

2016-06-01

Ibrutinib, a Bruton tyrosine kinase inhibitor, is a new targeted agent approved by the US Food and Drug Administration for the treatment of chronic lymphocytic leukemia (CLL), mantle cell lymphoma, and Waldenström macroglobulinemia. Ibrutinib is overall well tolerated but long-term treatment is required until disease progression or intolerable toxic effects occur. Little is known regarding its cutaneous adverse effects. To describe the hair and nail manifestations associated with the long-term use of ibrutinib for the treatment of CLL. Prospective study of 66 patients with CLL enrolled in a single-arm phase 2 clinical trial of ibrutinib for CLL between March 2014 and October 2015 at the National Institutes of Health. The primary outcome, nail and hair changes associated with ibrutinib therapy, was assessed by an 11-question survey. In addition, the severity of nail changes was determined from a 0 to 3 rating scale for both onychoschizia and onychorrhexis. Among 66 patients (43 men and 23 women with ages ranging from 55 to 85 years), 44 (67%) reported brittle fingernails at a median of 6.5 (95% CI, 6-12) months after starting ibrutinib therapy. Fifteen patients (23%) developed brittle toenails after a median of 9 (95% CI, 6-15) months of ibrutinib therapy. Textural hair changes were reported in 17 patients (26%), at a median of 9 (95% CI, 6-12) months of ibrutinib treatment. Hair and nail abnormalities are commonly associated with ibrutinib and appear several months after initiating therapy. Ibrutinib inhibits Bruton tyrosine kinase by covalently binding to cysteine 481. Whether ibrutinib affects the hair and nails by binding and altering cysteine-rich proteins of hair and nails or by means of another mechanism remains unknown. clinicaltrials.gov Identifier: NCT01500733.

Evidence of long-term change in zonal wind in the tropical lower mesosphere: Observations and model simulations

Czech Academy of Sciences Publication Activity Database

Ratnam, M. V.; Kumar, G. K.; Rao, N. V.; Murthy, B. V. K.; Laštovička, Jan; Qian, L.

2013-01-01

Roč. 40, č. 2 (2013), s. 397-401 ISSN 0094-8276 R&D Projects: GA ČR GAP209/10/1792 Institutional support: RVO:68378289 Keywords : mesosphere * zonal wind * long-term trends * TIME-GCM * climate change Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 4.456, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/grl.50158/abstract

Ecosystem processes and human influences regulate streamflow response to climate change at long-term ecological research sites

Science.gov (United States)

Julia A. Jones; Irena F. Creed; Kendra L. Hatcher; Robert J. Warren; Mary Beth Adams; Melinda H. Benson; Emery Boose; Warren A. Brown; John L. Campbell; Alan Covich; David W. Clow; Clifford N. Dahm; Kelly Elder; Chelcy R. Ford; Nancy B. Grimm; Donald L Henshaw; Kelli L. Larson; Evan S. Miles; Kathleen M. Miles; Stephen D. Sebestyen; Adam T. Spargo; Asa B. Stone; James M. Vose; Mark W. Williams

2012-01-01

Analyses of long-term records at 35 headwater basins in the United States and Canada indicate that climate change effects on streamflow are not as clear as might be expected, perhaps because of ecosystem processes and human influences. Evapotranspiration was higher than was predicted by temperature in water-surplus ecosystems and lower than was predicted in water-...

Long-term decline of radiocaesium in Fennoscandian reindeer

International Nuclear Information System (INIS)

Skuterud, L.; Aahman, B.; Solatie, D.; Gaare, E.

2009-06-01

The NKS-B project REIN was established to synthesize the available information on contamination levels and effective half-times for 137Cs in reindeer in Finland, Sweden and Norway. Several studies of radiocaesium contamination in reindeer have been carried out in the Nordic countries over the last 50 years. However, the current slow decline in concentrations, which will maintain the consequences of the Chernobyl deposition for Swedish and Norwegian reindeer husbandry for at least another 10-20 years, have not previously been observed nor predicted. In the Chernobyl affected areas 137Cs concentrations in reindeer initially declined by effective half-times of 3-4 years, whereas the current decline appears to be mainly governed by the nuclide's physical half-life (30 years). The review of effective half-times of 137Cs in reindeer across Fennoscandia suggests that concentrations declined more rapidly in the northernmost areas. The reason(-s) remains unclear, and demonstrates the need for more long-term sampling of the various components of reindeer's diet. Such sampling should aim at covering climatically different areas, as climate may influence transfer of radiocaesium to reindeer via lichen growth and weathering rates, composition of plant communities and lichen availability, as well as soil-to-plant radiocaesium uptake. The lack of long-term data on radiocaesium in natural vegetation in the Nordic countries is one of the main limitations for the development of mechanistic models for radiocaesium in reindeer, and for further elucidation of the observed long-term trends in 137Cs concentrations in reindeer. Currently our understanding of the long-term trends observed in various areas is not good enough to predict how future radiocaesium deposition will behave. The high transfer of nuclides to reindeer, the geographical extension of reindeer herding and the special position of the Sami population in Finland, Sweden and Norway, demonstrates the need for maintaining

Long-term decline of radiocaesium in Fennoscandian reindeer

Energy Technology Data Exchange (ETDEWEB)

Skuterud, L. (Norwegian Radiation Protection Authority, Norwegian Reindeer Husbandry Administration (Norway)); AAhman, B. (Swedish Univ. of Agricultural Sciences (Sweden)); Solatie, D. (STUK-Radiation and Nuclear Safety Authority (Finland)); Gaare, E. (Norwegian Institute for Nature Researc (Norway))

2009-06-15

The NKS-B project REIN was established to synthesize the available information on contamination levels and effective half-times for 137Cs in reindeer in Finland, Sweden and Norway. Several studies of radiocaesium contamination in reindeer have been carried out in the Nordic countries over the last 50 years. However, the current slow decline in concentrations, which will maintain the consequences of the Chernobyl deposition for Swedish and Norwegian reindeer husbandry for at least another 10-20 years, have not previously been observed nor predicted. In the Chernobyl affected areas 137Cs concentrations in reindeer initially declined by effective half-times of 3-4 years, whereas the current decline appears to be mainly governed by the nuclide's physical half-life (30 years). The review of effective half-times of 137Cs in reindeer across Fennoscandia suggests that concentrations declined more rapidly in the northernmost areas. The reason(-s) remains unclear, and demonstrates the need for more long-term sampling of the various components of reindeer's diet. Such sampling should aim at covering climatically different areas, as climate may influence transfer of radiocaesium to reindeer via lichen growth and weathering rates, composition of plant communities and lichen availability, as well as soil-to-plant radiocaesium uptake. The lack of long-term data on radiocaesium in natural vegetation in the Nordic countries is one of the main limitations for the development of mechanistic models for radiocaesium in reindeer, and for further elucidation of the observed long-term trends in 137Cs concentrations in reindeer. Currently our understanding of the long-term trends observed in various areas is not good enough to predict how future radiocaesium deposition will behave. The high transfer of nuclides to reindeer, the geographical extension of reindeer herding and the special position of the Sami population in Finland, Sweden and Norway, demonstrates the need for

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

MC1 dynamic global vegetation model simulates vegetation response to climate change by simulating vegetation production, soil biogeochemistry, plant biogeography and fire. It has been applied at a wide range of spatial scales, yet the spatio-temporal patterns of simulated vegetation production, which drives the model's response to climate change, has not been examined in detail. We ran MC1 for California at a relatively fine scale, 30 arc-seconds, for the historical period (1895-2006) and for the future (2007-2100), using downscaled data from four CMIP3-based climate projections: A2 and B1 GHG emissions scenarios simulated by PCM and GFDL GCMs. The use of these four climate projections aligns our work with a body of climate change research work commissioned by the California Public Interest Energy Research (PIER) Program. The four climate projections vary not only in terms of changes in their annual means, but in the seasonality of projected climate change. We calibrated MC1 using MODIS NPP data for 2000-2011 as a guide, and adapting a published technique for adjusting simulated vegetation production by increasing the simulated plant rooting depths. We evaluated the simulation results by comparing the model output for the historical period with several benchmark datasets, summarizing by EPA Level 3 Ecoregions. Multi-year summary statistics of model predictions compare moderately well with Kuchler's potential natural vegetation map, National Biomass and Carbon Dataset, Leenhouts' compilation of fire return intervals, and, of course, the MODIS NPP data for 2000-2011. When we compared MC1's monthly NPP values with MODIS monthly GPP data (2000-2011), however, the seasonal patterns compared very poorly, with NPP/GPP ratio for spring (Mar-Apr-May) often exceeding 1, and the NPP/GPP ratio for summer (Jun-Jul-Aug) often flattening to zero. This suggests MC1's vegetation production algorithms are overly biased for spring production at the cost of summer production. We

miRNA control of vegetative phase change in trees.

Directory of Open Access Journals (Sweden)

Jia-Wei Wang

2011-02-01

Full Text Available After germination, plants enter juvenile vegetative phase and then transition to an adult vegetative phase before producing reproductive structures. The character and timing of the juvenile-to-adult transition vary widely between species. In annual plants, this transition occurs soon after germination and usually involves relatively minor morphological changes, whereas in trees and other perennial woody plants it occurs after months or years and can involve major changes in shoot architecture. Whether this transition is controlled by the same mechanism in annual and perennial plants is unknown. In the annual forb Arabidopsis thaliana and in maize (Zea mays, vegetative phase change is controlled by the sequential activity of microRNAs miR156 and miR172. miR156 is highly abundant in seedlings and decreases during the juvenile-to-adult transition, while miR172 has an opposite expression pattern. We observed similar changes in the expression of these genes in woody species with highly differentiated, well-characterized juvenile and adult phases (Acacia confusa, Acacia colei, Eucalyptus globulus, Hedera helix, Quercus acutissima, as well as in the tree Populus x canadensis, where vegetative phase change is marked by relatively minor changes in leaf morphology and internode length. Overexpression of miR156 in transgenic P. x canadensis reduced the expression of miR156-targeted SPL genes and miR172, and it drastically prolonged the juvenile phase. Our results indicate that miR156 is an evolutionarily conserved regulator of vegetative phase change in both annual herbaceous plants and perennial trees.

Creep deformation behavior at long-term in P23/T23 steels

Energy Technology Data Exchange (ETDEWEB)

Sawada, K.; Tabuchi, M.; Kimura, K. [National Institute for Materials Science (Japan)

2008-07-01

Creep behavior of ASME P23/T23 steels was investigated and analyzed, focusing on creep strength degradation at long-term. Creep rupture strength at 625 C and 650 C dropped at long-term in both P23 and T23 steels. The stress exponent of minimum creep rate at 625 C and 650 C was 7.8-13 for higher stresses and 3.9-5.3 for lower stresses in the P23/T23 steels. The change of stress exponent with stress levels was consistent with the drop in creep rupture strength at long-term. The Monkman-Grant rule was confirmed in the range examined in P23 steel, while the data points deviated from the rule at long-term in the case of T23 steel. The creep ductility of P23 steel was high over a wide stress and temperature range. On the other hand, in T23 steel, creep ductility at 625 C and 650 C decreased as time to rupture increased. The change in ductility may cause the deviation from the Monkman-Grant rule. Fracture mode changed from transgranular to intergranular fracture in the long-term at 625 C and 650 C. (orig.)

Changes in water and beverage intake and long-term weight changes: results from three prospective cohort studies.

Science.gov (United States)

Pan, A; Malik, V S; Hao, T; Willett, W C; Mozaffarian, D; Hu, F B

2013-10-01

To examine the long-term relationship between changes in water and beverage intake and weight change. Prospective cohort studies of 50013 women aged 40-64 years in the Nurses' Health Study (NHS, 1986-2006), 52987 women aged 27-44 years in the NHS II (1991-2007) and 21988 men aged 40-64 years in the Health Professionals Follow-up Study (1986-2006) without obesity and chronic diseases at baseline. We assessed the association of weight change within each 4-year interval, with changes in beverage intakes and other lifestyle behaviors during the same period. Multivariate linear regression with robust variance and accounting for within-person repeated measures were used to evaluate the association. Results across the three cohorts were pooled by an inverse-variance-weighted meta-analysis. Participants gained an average of 1.45 kg (5th to 95th percentile: -1.87 to 5.46) within each 4-year period. After controlling for age, baseline body mass index and changes in other lifestyle behaviors (diet, smoking habits, exercise, alcohol, sleep duration, TV watching), each 1 cup per day increment of water intake was inversely associated with weight gain within each 4-year period (-0.13 kg; 95% confidence interval (CI): -0.17 to -0.08). The associations for other beverages were: sugar-sweetened beverages (SSBs) (0.36 kg; 95% CI: 0.24-0.48), fruit juice (0.22 kg; 95% CI: 0.15-0.28), coffee (-0.14 kg; 95% CI: -0.19 to -0.09), tea (-0.03 kg; 95% CI: -0.05 to -0.01), diet beverages (-0.10 kg; 95% CI: -0.14 to -0.06), low-fat milk (0.02 kg; 95% CI: -0.04 to 0.09) and whole milk (0.02 kg; 95% CI: -0.06 to 0.10). We estimated that replacement of 1 serving per day of SSBs by 1 cup per day of water was associated with 0.49 kg (95% CI: 0.32-0.65) less weight gain over each 4-year period, and the replacement estimate of fruit juices by water was 0.35 kg (95% CI: 0.23-0.46). Substitution of SSBs or fruit juices by other beverages (coffee, tea, diet beverages, low-fat and whole milk) were all

Centennial-scale vegetation and climate changes in the Middle Atlas, Morocco: new insights from multi-proxy investigations at Lake Sidi Ali

Science.gov (United States)

Fletcher, William; Campbell, Jennifer; Joannin, Sebastien; Mischke, Steffen; Zielhofer, Christoph; de Batist, Marc; Mikdad, Abdes

2016-04-01

The karstic lakes of the Middle Atlas, Morocco, represent a valuable archive of environmental and climatic change for Northwest Africa. Here we present the results of centennial-scale palynological and charcoal analyses as part of a multiproxy palaeolimnological study of sediment cores from Lake Sidi Ali in the Middle Atlas, Morocco (33° 03 N, 05° 00 W; 2,080 m a.s.l.). Supported by absolute dating including 23 more than twenty AMS 14C dates on pollen concentrates, the record covers the entire Holocene and offers insights into vegetation and climate change at a regionally unprecedented centennial-scale. Pollen assemblages are dominated by steppic herbs, evergreen oaks (Quercus), junipers (Cupressaceae) and Atlantic cedar (Cedrus atlantica). A long-term evolution of the montane vegetation is recorded, reflecting progressive changes in the dominant arboreal taxa and leading to the full establishment of the emblematic cedar forests of the area during the mid-Holocene by 6000 cal BP. Orbital-scale changes in seasonality and growing season moisture availability linked to declining summer insolation are implicated, with a transition from (a) warm, dry summers associated with summer drought tolerant taxa especially evergreen Quercus, high algal productivity in the lake, and high background levels of microcharcoal reflecting distant fire activity during the early Holocene, to (b) cool, relatively humid summers with dominance of montane conifers, declining algal productivity in the lake, and episodic local fire activity during the mid- to late Holocene. Superimposed on the long-term environmental changes are recurrent centennial-scale fluctuations in vegetation composition, reflecting competitive dynamics between the major taxa, initially between steppic and arboreal elements, and later between the major tree taxa. Parallels with hydrological proxies including stable O and C isotopes suggest common responses to climatic drivers (fluctuations in moisture sources and

Carbon accumulation in a permafrost polygon peatland: steady long-term rates in spite of shifts between dry and wet conditions.

Science.gov (United States)

Gao, Yang; Couwenberg, John

2015-02-01

Ice-wedge polygon peatlands contain a substantial part of the carbon stored in permafrost soils. However, little is known about their long-term carbon accumulation rates (CAR) in relation to shifts in vegetation and climate. We collected four peat profiles from one single polygon in NE Yakutia and cut them into contiguous 0.5 cm slices. Pollen density interpolation between AMS (14)C dated levels provided the time span contained in each of the sample slices, which--in combination with the volumetric carbon content--allowed for the reconstruction of CAR over decadal and centennial timescales. Vegetation representing dry palaeo-ridges and wet depressions was reconstructed with detailed micro- and macrofossil analysis. We found repeated shifts between wet and dry conditions during the past millennium. Dry ridges with associated permafrost growth originated during phases of (relatively) warm summer temperature and collapsed during relatively cold phases, illustrating the important role of vegetation and peat as intermediaries between ambient air temperature and the permafrost. The average long-term CAR across the four profiles was 10.6 ± 5.5 g C m(-2) yr(-1). Time-weighted mean CAR did not differ significantly between wet depression and dry ridge/hummock phases (10.6 ± 5.2 g C m(-2) yr(-1) and 10.3 ± 5.7 g C m(-2) yr(-1), respectively). Although we observed increased CAR in relation to warm shifts, we also found changes in the opposite direction and the highest CAR actually occurred during the Little Ice Age. In fact, CAR rather seems to be governed by strong internal feedback mechanisms and has roughly remained stable on centennial time scales. The absence of significant differences in CAR between dry ridge and wet depression phases suggests that recent warming and associated expansion of shrubs will not affect long-term rates of carbon burial in ice-wedge polygon peatlands. © 2014 John Wiley & Sons Ltd.

Long-term Morbidity of Testicular Cancer Treatment.

Science.gov (United States)

Fung, Chunkit; Fossa, Sophie D; Williams, Annalynn; Travis, Lois B

2015-08-01

Second malignant neoplasms, cardiovascular disease, neurotoxicity and ototoxicity, pulmonary complications, hypogonadism, and nephrotoxicity are potentially life-threatening long-term complications of testicular cancer and its therapy. This article describes the pathogenesis, risks, and management of these late effects experienced by long-term testicular cancer survivors, who are defined as individuals who are disease free 5 years or more after primary treatment. Testicular cancer survivors should follow applicable national guidelines for cancer screening and management of cardiovascular disease risk factors. In addition, health care providers should capitalize on the time of cancer diagnosis as a teachable moment to introduce and promote lifestyle changes. Copyright © 2015 Elsevier Inc. All rights reserved.

Labile and Non-labile Soil Carbon Fractions Equally Contributed to Carbon Changes under Long-term Fertilization

Science.gov (United States)

Liang, F.; Li, J.; Xu, M.; Huang, S.

2017-12-01

Soil organic carbon (SOC) storages are altered under long-term fertilization in croplands, it however remains unclear how fast- to slow-cycling SOC fractions each respond to fertilization practices. Based on five two-decade Chinese long-term fertilization experiments (GZL: Gongzhuling; ZZ: Zhengzhou; CQ: Chongqing; JX: Jinxian; QY: Qiyang) under three fertilization treatments (CK: cropping with no fertilizer input; NPK: chemical nitrogen, phosphorus and potassium fertilizers; and NPKM: NPK with manure input), we quantified very labile, labile, non-labile and total SOC stocks at 0-20cm soil depth. Results showed that SOC stocks varied among sites (GZL, JX, CQ > ZZ, QY) and generally increased with fertilizations (CK-1 at ZZ, GZL, QY, CQ and JX, respectively. The corresponding changes of the sum of very labile and labile SOC fractions were 2.6, 2.0, 1.8, 0.8 and -0.5 Mg ha-1 at ZZ, QY, GZL, CQ and JX, respectively. Also, NPKM increased total SOC stock by 18.3, 16.2, 14.4, 10.5, and 6.5 Mg ha-1 at QY, GZL, ZZ, CQ and JX, respectively. The corresponding changes of the sum of very labile and labile SOC fractions were 8.6, 6.8, 6.6, 3.2 and -1.6 Mg ha-1 at QY, GZL, ZZ, CQ and JX, respectively. These results suggested that about half or more than half SOC stock accretions under fertilization were induced by increase in non-labile SOC fractions. It thus informs the importance of non-labile SOC fractions in contributing to soil C sequestration under long-term fertilizations in Chinese croplands. Future research should improve our mechanistic understanding of biogeochemical transformation of non-labile organic C in soils.

Analysing long-term changes of everyday life in an environmental perspective

DEFF Research Database (Denmark)

Røpke, Inge

2004-01-01

for increasing consumption in developing countries. This problem of ever increasing quantities of consumption ought to be placed high on the sustainable development agenda, and it calls for research on the dynamics behind the growth to improve the possibilities for curbing it. A real challenge in relation...... to this issue is that the increases in consumption are imperceptible and that most people in the industrialized countries are preoccupied with managing their everyday lives and do not experience that they live in any kind of extreme luxury. Some years ago I wrote a paper dealing with this issue in general terms......The background of this paper is an interest in the ever growing consumption in the industrialized countries. The macro level growth rate changes over time, but most years it is positive and over the long run the increase is impressive – for instance, a growth rate of 2 percent implies a doubling...

Detection and mapping of long-term land degradation and desertification in Arab region using MODESERT

International Nuclear Information System (INIS)

Faour, GH.

2014-01-01

This paper presents the definition and formulation of a remotely sensed based monitoring system for land degradation and desertification. The main objective of this system is to identify processes of land degradation and desertification sensitive areas at regional scale. The proposed methodology relies on the use of time series NDVI images generated from remote sensing satellites for the regional assessment and monitoring of vegetation dynamics. Parametric model based on ordinary least-squares regression was developed and implemented through the use of MODESERT, an open-source software developed by the National Council for Scientific Research in Lebanon (CNRS). The study area covers the entire Arab World. Long term trends were derived using the GIMMS NDVI data set over the time period between 1982 and 2006. It is the longest series of NDVI product covering our regions. Three main classes, subdivided into seven groups,were established representing: moderately to highly sensitive areas, areas with no-significant change, moderately to highly developed areas. Mean absolute percentage error (MAPE) was used to estimate the accuracy of the trend model; it generated a mean error at5-10%. Results indicatedthat more than 40% of the total MENA region weresensitive to land degradation and desertification. In contrast,only less than 5% of the region had witnessed positive changes in vegetation cover. The major drivers ofland degradation were mainly linked to climate variability and recurring drought and to less extent their sub-drivers such as forest firesand the poor socio economic development. Development in vegetation cover was found to occur at larger scalesin Southern Somalia, Sudan and Southern Iraq marshlands.This method could be applied to nationalscaleassessment. Using others satellites images (e.g. SPOT Vegetation, MOD13Q1, etc...) has alsopotential.This monitoring system is operational since 2007 and was validated through the publication of the biennial Arab

Long Term Incentives for Residential Customers Using Dynamic Tariff

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Nielsen, Arne Hejde

2015-01-01

This paper reviews several grid tariff schemes, including flat tariff, time-of-use, time-varying tariff, demand charge and dynamic tariff (DT), from the perspective of the long term incentives. The long term incentives can motivate the owners of flexible demands to change their energy consumption...... behavior in such a way that the power system operation issues, such as system balance and congestion, can be alleviated. From the comparison study, including analysis and case study, the DT scheme outperforms the other tariff schemes in terms of cost saving and network operation condition improving....

Colour changes in prints during long-term dark storage of prints

International Nuclear Information System (INIS)

Parraman, Carinna

2010-01-01

The most significant impact on colour fading in prints is exposure to light and air. However what happens to coloured prints during long-term storage in boxes, drawers and on shelves? Measurements of samples, printed in July 2005, stored in a range of light and darkened storage conditions have shown some interesting initial results. As more emphasis is placed on the effects of light, the dark stability of inkjet prints is relatively overlooked when considering how to preserve or store coloured prints. This study and presentation builds on previous research [1] and has concentrated on the changes to colour during storage. With reference to ASTM F2035 - 00(2006) Standard Practice for Measuring the Dark Stability of Ink Jet Prints, the Standards outline points out that whilst natural aging is the most reliable method of assessing image stability, materials and inks any data that is produced quickly becomes redundant; therefore accelerated aging is more preferred. However, the fine art materials in this study are still very much in circulation. The leading fine art papers, and pigmented ink-sets used in these trials are still being used by artists. We can therefore demonstrate the characteristics of colour changes and the impact of ink on paper that utilises natural aging methods.

Long-term selenium status in humans

International Nuclear Information System (INIS)

Baskett, C.K.; Spate, V.L.; Mason, M.M.; Nichols, T.A.; Williams, A.; Dubman, I.M.; Gudino, A.; Denison, J.; Morris, J.S.

2001-01-01

The association of sub-optimal selenium status with increased risk factors for some cancers has been reported in two recent epidemiological studies. In both studies the same threshold in selenium status was observed, below which, cancer incidence increased. To assess the use of nails as a biologic monitor to measure the long-term selenium status, an eight-year longitudinal study was undertaken with a group of 11 adult subjects, 5 women and 6 men. Selenium has been measured by instrumental neutron activation analysis. Differences between fingernails and toenails with be discussed. In addition, the results will be discussed in the context of the long-term stability of the nail monitor to measure selenium status during those periods when selenium determinants are static; and the changes that occur as a result of selenium supplementation. (author)

Detecting Historical Vegetation Changes in the Dunhuang Oasis Protected Area Using Landsat Images

Directory of Open Access Journals (Sweden)

Xiuxia Zhang

2017-09-01

Full Text Available Abstract: Given its proximity to an artificial oasis, the Donghu Nature Reserve in the Dunhuang Oasis has faced environmental pressure and vegetation disturbances in recent decades. Satellite vegetation indices (VIs can be used to detect such changes in vegetation if the satellite images are calibrated to surface reflectance (SR values. The aim of this study was to select a suitable VI based on the Landsat Climate Data Record (CDR products and the absolute radiation-corrected results of Landsat L1T images to detect the spatio-temporal changes in vegetation for the Donghu Reserve during 1986–2015. The results showed that the VI difference (ΔVI images effectively reduced the changes in the source images. Compared with the other VIs, the soil-adjusted vegetation index (SAVI displayed greater robustness to atmospheric effects in the two types of SR images and was more responsive to vegetation changes caused by human factors. From 1986 to 2015, the positive changes in vegetation dominated the overall change trend, with changes in vegetation in the reserve decreasing during 1990–1995, increasing until 2005–2010, and then decreasing again. The vegetation changes were mainly distributed at the edge of the artificial oasis outside the reserve. The detected changes in vegetation in the reserve highlight the increased human pressure on the reserve.

Long-term changes in net radiation and its components above a pine forest and a grass surface in Germany

International Nuclear Information System (INIS)

Kessler, A.; Jaeger, L.

1999-01-01

Long-term measurements (1974–1993 and 1996, respectively) of the net radiation (Q), global radiation (G), reflected global radiation (R), long-wave atmospheric radiation (A) and thermal radiation (E) of a pine forest in Southern Germany (index p) and of a grass surface in Northern Germany (index g) are compared. The influence of changes in surface properties is discussed. There are, in the case of the pine stand, forest growth and forest management and in the case of the grass surface, the shifting of the site from a climatic garden to a horizontal roof. Both series of radiant fluxes are analyzed with respect to the influences of the weather (cloudiness, heat advection). To eliminate the different influence of the solar radiation of the two sites, it is necessary to normalize by means of the global radiation G, yielding the radiation efficiency Q/G, the albedo R/G=α and the normalized long-wave net radiation (A+E)/G. Furthermore, the long-term mean values and the long-term trend of yearly mean values are discussed and, moreover, a comparison is made of individual monthly values. Q p is twice as large as Q g . The reason for this is the higher values of G and A above the pine forest and half values of α p compared to α g . E p is only a little greater than E g . The time series of the radiation fluxes show the following trends: Q p declines continuously despite a slight increase of G p . This is mainly due to the long-wave radiation fluxes. The net radiation of the grass surface Q g shows noticeably lower values after the merging of the site. This phenomenon is also dominated by the long-wave radiation processes. Although the properties of both site surfaces alter, E p and E g remain relatively stable. A p and A g show a remarkable decrease however. The reason for this is to be found in a modification of the heat advection, showing a more pronounced impact on the more continentally exposed site (pine forest). Compared to α g , α p shows only a small

Updated vegetation information in high resolution regional climate simulations using WRF

DEFF Research Database (Denmark)

Nielsen, Joakim Refslund; Dellwik, Ebba; Hahmann, Andrea N.

Climate studies show that the frequency of heat wave events and above-average high temperatures during the summer months over Europe will increase in the coming decades. Such climatic changes and long-term meteorological conditions will impact the seasonal development of vegetation and ultimately...... modify the energy distribution at the land surface. In weather and climate models it is important to represent the vegetation variability accurately to obtain reliable results. The weather research and forecasting (WRF) model uses a green vegetation fraction (GVF) climatology to represent the seasonal...... or changes in management practice since it is derived more than twenty years ago. In this study, a new high resolution, high quality GVF product is applied in a WRF climate simulation over Denmark during the 2006 heat wave year. The new GVF product reflects the year 2006 and it was previously tested...

Long Term Financing of Infrastructure

OpenAIRE

Sinha, Sidharth

2014-01-01

Infrastructure projects, given their long life, require long term financing. The main sources of long term financings are insurance and pension funds who seek long term investments with low credit risk. However, in India household financial savings are mainly invested in bank deposits. Insurance and pension funds account for only a small percentage of household financial savings. In addition most infrastructure projects do not qualify for investment by insurance and pension funds because of t...

Expanding research capabilities with sea ice climate records for analysis of long-term climate change and short-term variability

Science.gov (United States)

Scott, D. J.; Meier, W. N.

2008-12-01

Recent sea ice analysis is leading to predictions of a sea ice-free summertime in the Arctic within 20 years, or even sooner. Sea ice topics, such as concentration, extent, motion, and age, are predominately studied using satellite data. At the National Snow and Ice Data Center (NSIDC), passive microwave sea ice data sets provide timely assessments of seasonal-scale variability as well as consistent long-term climate data records. Such data sets are crucial to understanding changes and assessing their impacts. Noticeable impacts of changing sea ice conditions on native cultures and wildlife in the Arctic region are now being documented. With continued deterioration in Arctic sea ice, global economic impacts will be seen as new shipping routes open. NSIDC is at the forefront of making climate data records available to address the changes in sea ice and its global impacts. By focusing on integrated data sets, NSIDC leads the way by broadening the studies of sea ice beyond the traditional cryospheric community.

Long-term studies of the natural history of asthma in childhood

DEFF Research Database (Denmark)

Bisgaard, Hans; Bønnelykke, Klaus

2010-01-01

secondary prevention through the use of inhaled corticosteroids can effectively halt the long-term disease progression in childhood. In conclusion, the natural history of asthma and the associated airway changes is still poorly understood, and we have not managed to translate findings from long-term studies...

Impact of dam-induced hydrological changes on riparian vegetation

Science.gov (United States)

Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

2010-05-01

Hydrological disturbances are a key factor for the riparian vegetation, which is a highly dynamic ecosystem prone to external forcing. Random fluctuations of water stages drive in fact the alternation of periods of floods and exposure of the vegetated plots. During flooding, the plots are submerged and vegetation is damaged by burial, uprooting and anoxia, while during exposure periods vegetation grows according to the soil moisture content and the phreatic water table depth. The distribution of vegetation along the riparian transect is then directly connected to the stochasticity of river discharges. River damming can have remarkable impacts on the hydrology of a river and, consequently, on the riparian vegetation. Several field studies show how the river regulation induced by artificial reservoirs can greatly modify the statistical moments and the autocorrelation of the discharge time series. The vegetation responds to these changes reducing its overall heterogeneity, declining - substituted by exotic species - and shifting its starting position nearer or far away from the channel center. These latter processes are known as narrowing and widening, respectively. In our work we explore the effects of dam-induced hydrological changes on the narrowing/widening process and on the total biomass along the transect. To this aim we use an eco-hydrological stochastic model developed by Camporeale and Ridolfi [2006], which is able to give a realistic distribution of the biomass along the transect as a function of a few hydrologic, hydraulic and vegetation parameters. We apply the model to an exemplifying case, by investigating the vegetation response to a set of changes in mean discharge and coefficient of variation. The range of these changes is deduced from the analysis of field data in pre- and post-dam conditions. Firstly, we analyze the narrowing/widening process. In particular, we analyze two percentage differences of the starting transversal position with respect to

Long-term effect of a name change for schizophrenia on reducing stigma.

Science.gov (United States)

Koike, Shinsuke; Yamaguchi, Sosei; Ojio, Yasutaka; Shimada, Takafumi; Watanabe, Kei-ichiro; Ando, Shuntaro

2015-10-01

A name change for schizophrenia was first implemented in Japan for reducing stigma in 2002; however, little is known of its long-term impact. Total 259 students from 20 universities answered an anonymous self-administered questionnaire about their mental health-related experiences, and stigma scales including feasible knowledge and negative stereotypes for four specific diseases, including schizophrenia (old and new names), depression, and diabetes mellitus. We also asked to choose the old and new names of schizophrenia and dementia among ten names for mental and physical illnesses and conditions. The participants had more feasible knowledge and fewer negative stereotypes for the new name of schizophrenia than the old name, but were still significantly worse than for depression and diabetes mellitus (p stereotypes (β = 0.13, p = 0.020). The rate of correct responses for the old and new names of schizophrenia was significantly lower than that of dementia (41 vs. 87%, p media was associated with the recognition of name change for schizophrenia (p = 0.008), which was associated with less feasible knowledge for new name of schizophrenia. The name change of schizophrenia has reduced stigma since 12 years have passed. More effective campaigns, educational curricula, and policy making are needed to reduce stigma toward schizophrenia.

Has long-term metal exposure induced changes in life history traits and genetic diversity of the enchytraeid worm Cognettia sphagnetorum (Vejd.)?

International Nuclear Information System (INIS)

Haimi, Jari; Knott, Karelyn Emily; Selonen, Salla; Laurikainen, Marjo

2006-01-01

We studied whether long-term metal exposure has affected life history traits, population growth patterns and genetic diversity of the asexual enchytraeid worm Cognettia sphagnetorum (Vejd.). Enchytraeids from metal contaminated and uncontaminated forest soil were compared by growing them individually in the laboratory and by following their population development in patchily Cu contaminated microcosms. Genetic differences between the two native populations were studied using allozyme electrophoresis. Individuals from the contaminated site had slower growth rate and they produced fewer fragments of larger size when compared to individuals from the uncontaminated site. In patchily Cu contaminated microcosms, C. sphagnetorum from the contaminated site had a slower population growth rate. Most alleles were shared by the two native populations, but there was greater diversity and more unique genotypes in the population living in the uncontaminated site. Overall, long-term exposure to metals has induced only slight changes in life history properties and clonal diversity of C. sphagnetorum. - Long-term exposure to metals caused only small changes in life histories of two populations of Cognettia sphagnetorum

Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.

Directory of Open Access Journals (Sweden)

Zhiwei Wang

Full Text Available The Qinghai-Tibetan Plateau (QTP contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI product based on turning points (TPs, which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost

Long-term changes in ADAS-cog: what is clinically relevant for disease modifying trials in Alzheimer?

Science.gov (United States)

Vellas, B; Andrieu, S; Cantet, C; Dartigues, J F; Gauthier, S

2007-01-01

With the development of long-term disease modifying trials, changes in ADAS-Cog at 18 months will rise certainly many questions. We decided to look in the Real.fr study at the links between changes in cognition, ADAS-Cog and function. A total of 346 Alzheimer's patients with ADAS-cog at entry and at 18 months. were eligible for this analysis. These patients were on average 77.44 years old and 254 (72.36%) were women. The great majority lived at home and about 93% were treated with a cholinesterase inhibitor at baseline. Thirty three patients (9%) had a gain of more than 2 points at the ADAS-cog at 18 months (Group I, improvement); 130 (38%) were considered as stable, the reference group (Group II ) characterized by a stability at the ADAS-cog: decline of 2 points to gain of 2 points, 112 subjects (32%) had a moderate decline between 2 and 7 at the ADAScog (Group III) and finally 71 subjects (21%) had a severe impairment more than seven points at the ADAS-cog. A loss of one Basic ADL is certainly highly relevant, and such a change was found at 18 months in more than half of the subjects, which is not surprising for a long-term evolution in mild to moderate AD. An impairment of more than 7 points at the ADAS-cog was found in 21% of the subjects at 18 months and was associated with loss.

Becoming a normal guy: Men making sense of long-term bodily changes following bariatric surgery

Directory of Open Access Journals (Sweden)

Karen Synne Groven

2015-12-01

Full Text Available Background: To date, research on bodily changes following bariatric surgery has focused predominantly on women, leaving the long-term experience of men relatively unexplored. In this paper, we draw on interviews with men who have undergone an irreversible gastric bypass procedure to explore their bodily changes more than 4 years post-surgery. We apply a phenomenological framework that draws on Leder's perspectives on the “disappearing” and “dys-appearing” body, combined with a gender-sensitive lens that draws on Connell's theory of hegemonic masculinity and Robertson's conceptions of embodied masculinity. Findings: Our principal finding was that the men negotiated their bodily changes following bariatric surgery in profoundly ambivalent ways. Although they enthusiastically praised the surgery for improving their health, self-esteem, and social functioning, they also emphasized their efforts to cope with post-surgical side effects and life-threatening complications. Our analysis elaborates on their efforts to adjust to and come to terms with these changes, focusing on episodes of hypoglycemia, severe pain and internal herniation, and the significance of physical activity and exercise. Conclusions: Our findings point to the need to acknowledge men's ways of making sense of profound and ongoing bodily changes following bariatric surgery and how these negotiations are closely intertwined with masculine ideals of embodiment and social value.

Long term stability of power systems

Energy Technology Data Exchange (ETDEWEB)

Kundur, P; Gao, B [Powertech Labs. Inc., Surrey, BC (Canada)

1994-12-31

Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

Nuclear Energy, Long Term Requirements

International Nuclear Information System (INIS)

Knapp, V.

2006-01-01

There are serious warnings about depletion of oil and gas and even more serious warnings about dangers of climate change caused by emission of carbon dioxide. Should developed countries be called to replace CO2 emitting energy sources as soon as possible, and the time available may not be longer then few decades, can nuclear energy answer the call and what are the requirements? Assuming optimistic contribution of renewable energy sources, can nuclear energy expand to several times present level in order to replace large part of fossil fuels use? Paper considers intermediate and long-term requirements. Future of nuclear power depends on satisfactory answers on several questions. First group of questions are those important for near and intermediate future. They deal with economics and safety of nuclear power stations in the first place. On the same time scale a generally accepted concept for radioactive waste disposal is also required. All these issues are in the focus of present research and development. Safer and more economical reactors are targets of international efforts in Generation IV and INPRO projects, but aiming further ahead these innovative projects are also addressing issues such as waste reduction and proliferation resistance. However, even assuming successful technical development of these projects, and there is no reason to doubt it, long term and large-scale nuclear power use is thereby not yet secured. If nuclear power is to play an essential role in the long-term future energy production and in reduction of CO2 emission, than several additional questions must be replied. These questions will deal with long-term nuclear fuel sufficiency, with necessary contribution of nuclear power in sectors of transport and industrial processes and with nuclear proliferation safety. This last issue is more political then technical, thus sometimes neglected by nuclear engineers, yet it will have essential role for the long-term prospects of nuclear power. The

Effect of Low-Fat vs. Other Diet Interventions on Long-Term Weight Change in Adults: A Systematic Review and Meta-Analysis

OpenAIRE

Tobias, Deirdre K.; Chen, Mu; Manson, JoAnn E.; Ludwig, David S.; Willett, Walter; Hu, Frank B.

2015-01-01

Background: The effectiveness of low-fat diets for long-term weight loss has been debated for decades, with dozens of randomized trials (RCTs) and recent reviews giving mixed results. Methods: We conducted a random effects meta-analysis of RCTs to estimate the long-term effect of low-fat vs. higher fat dietary interventions on weight loss. Our search included RCTs conducted in adult populations reporting weight change outcomes at ≥1 year, comparing low-fat with higher fat interventions, publi...

The role of long-term geologic changes in the regulation of the Canadian nuclear fuel waste management program

International Nuclear Information System (INIS)

Flavelle, P.

1996-01-01

It is recognized that the geosphere is a dynamic system over the long time frames of nuclear fuel waste disposal. This paper describes how consideration of a dynamic geosphere has impacted upon the evolving regulatory environment in Canada, and how the approach taken to comply with the regulatory requirements can affect the evaluation of long-term geologic changes. AECB staff opinion is that if the maximum possible effect of geologic changes can be demonstrated to have negligible impact on the safety of a nuclear fuel waste repository, then further consideration of a dynamic geosphere is unnecessary for the current review of the Canadian Nuclear Fuel Waste Management Program. (authors). 7 refs., 4 figs