WorldWideScience
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Investigation of Vegetation Dynamics using Long-Term NormalizedDifference Vegetation Index Time-Series  

OpenAIRE

Abstract: Problem statement: The Normalized Difference Vegetation Index (NDVI) is the most extensively used satellite-derived index of vegetation health and density. Since climate is one of the most important factors affecting vegetation condition, satellite-derived vegetation indexes have been often used to evaluate climatic and environmental changes at regional and global scale. The proposed study attempted to investigate the temporal vegetation dynamics in the whole Africa using historical...

Perez, Francesca; Boccardo, Piero; Bellone, Tamara

2009-01-01

2

Investigation of Vegetation Dynamics using Long-Term Normalized Difference Vegetation Index Time-Series  

OpenAIRE

Problem statement: The Normalized Difference Vegetation Index (NDVI) is the most extensively used satellite-derived index of vegetation health and density. Since climate is one of the most important factors affecting vegetation condition, satellite-derived vegetation indexes have been often used to evaluate climatic and environmental changes at regional and global scale. The proposed study attempted to investigate the temporal vegetation dynamics in the whole Africa using historical NDVI time...

Tamara Bellone; Piero Boccardo; Francesca Perez

2009-01-01

3

Investigation of Vegetation Dynamics using Long-Term Normalized Difference Vegetation Index Time-Series  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: The Normalized Difference Vegetation Index (NDVI is the most extensively used satellite-derived index of vegetation health and density. Since climate is one of the most important factors affecting vegetation condition, satellite-derived vegetation indexes have been often used to evaluate climatic and environmental changes at regional and global scale. The proposed study attempted to investigate the temporal vegetation dynamics in the whole Africa using historical NDVI time-series. Approach: For this aim, 15 day maximum value NDVI composites at 8 km spatial resolution produced from the NASA Global Inventory Mapping and Monitoring System (GIMMS had been used. They were derived from data collected daily by NOAA AVHRR satellites. The AVHRR NDVI GIMMS dataset was freely available and gives global coverage over an extensive time period. First of all, the selected NDVI base data had been geometrically pre-processed and organized into a historical database implemented in order to grant their spatial integration. Starting from this archive, monthly and yearly NDVI historical time-series, extended from 1982-2006, had been then developed and analysed on a pixel basis. Several routines hade been developed in IDL (Interactive Data Language programming tool with the purpose of applying suitable statistical analysis techniques to the historical information in the database in order to identify the long-term trend components of generated NDVI time-series and extract vegetation dynamics. Specific tests had been then considered in order to define the validity of results. Results: The existence of clear regional trends of NDVI, both decreasing and increasing had been showed, which helped to highlight areas subject, respectively to reduction or increase in vegetation greenness. Conclusion: As the relationship between the NDVI and vegetation productivity was well established, these estimated long-term trend components may be also, with much more caution, related to historical and ongoing land degradation or improvement processes.

Tamara Bellone

2009-01-01

4

Evaluation of vegetation cover using the normalized difference vegetation index (NDVI  

Directory of Open Access Journals (Sweden)

Full Text Available Soil loss by water erosion is the main cause of soil degradation in Brazil. However, erosion can be reduced by the presence of vegetation. The Normalized Difference Vegetation Index (NDVI makes it possible to identify the vegetative vigor of crops or natural vegetation which facilities the identification of areas with vegetation covers. This information is very important in identifying the phenomena which might be occurring in a particular area, especially those related to soil degradation by water erosion. Thus, the aim of this work was to assess the canopy cover by using NDVI, checking the image accuracy using the Coverage Index (CI based on the Stocking method, in the Sub-basin of Posses, which belongs to the Cantareira System, located in the Extrema municipality, Minas Gerais, Brazil. Landsat-5 TM images were used. The sub-basin of Posses was very altered in comparison to the surrounding areas. The NDVI technique proved to be a suitable tool to assess the uses that occur in the sub-basin of Posses, as validated by the Stocking methodology. The map derived from NDVI allowed the geographic distribution of different land uses to be observed and allowed for the identification of critical areas in relation to vegetation cover as well. This finding can be used to optimize efforts to recover and protect soil in areas with bare soil and degraded pasture, in order to reduce environmental degradation. The CI has not exceeded 40% for land use classes that occur in the majority of the sub-basin (91%, except in areas of woody vegetation.

Gabriela Camargos Lima

2013-08-01

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Integrated NDVI images for Niger 1986-1987. [Normalized Difference Vegetation Index  

Science.gov (United States)

Two NOAA AVHRR images are presented which provide a comparison of the geographic distribution of an integration of the normalized difference vegetation index (NDVI) for the Sahel zone in Niger for the growing seasons of 1986 and 1987. The production of the images and the application of the images for resource management are discussed. Daily large area coverage with a spatial resolution of 1.1 km at nadir were transformed to the NDVI and geographically registered to produce the images.

Harrington, John A., Jr.; Wylie, Bruce K.; Tucker, Compton J.

1988-01-01

6

Determination of Leaf Area Index, Total Foliar N, and Normalized Difference Vegetation Index for Arctic Ecosystems Dominated by Cassiope tetragona  

DEFF Research Database (Denmark)

Leaf area index (LAI) and total foliar nitrogen (TFN) are important canopy characteristics and crucial variables needed to simulate photosynthesis and ecosystem CO2 fluxes. Although plant communities dominated by Cassiope tetragona are widespread in the Arctic, LAI and TFN for this vegetation type have not been accurately quantified. We address this knowledge gap by (i) direct measurements of LAI and TFN for C. tetragona, and (ii) determining TFN-LAI and LAI–normalized difference vegetation index (NDVI) relationships for typical C. tetragona tundras in the subarctic (Sweden) and High Arctic (Greenland and Svalbard). Leaves of C. tetragona are 2–6 mm long and closely appressed to their stems forming parallelepiped shoots. We determined the LAI of C. tetragona by measuring the area of the leaves while still attached to the stem, then doubling the resulting one-sided area. TFN was determined from leaf N and biomass. The LAI-NDVI and TFN-LAI relationships showed high correlation and can be used to estimate indirectly LAI and TFN. The LAI-NDVI relationship for C. tetragona vegetation differed from a generic LAI-NDVI relationship for arctic tundra, whereas the TFN-LAI relationship did not. Overall, the LAI of C. tetragona tundra ranged from 0.4 to 1.1 m2 m–2 and TFN from 1.4 to 1.7 g N m–2.

Campioli, M; Street, LE

2009-01-01

7

Establishment of empirical relations between fuel moisture content and the normalised difference vegetation index  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english The object of the present research is to establish empirical relations between the Fuel Moisture Content (FMC) and the Normalised Difference Vegetation Index (NDVI) in pasture samples. The study area was the Carillanca Experimental Centre belonging to the Institute ofAgriculture and Livestock Resear [...] ch (Instituto de Investigaciones Agropecuarias - INIA), Araucanía Region, Chile. The study period ran from November 2011 to January 2012, in order to determine the variation in vegetation moisture content from spring, when plant cover is most vigorous, to summer when it declines to a minimum due to the summer drought. The application of a linear adjustment model produced correlation coefficients higher than 0.6.

M, Castro; J.C, Parra; L. J, Morales; C, Salas.

2014-09-01

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Fisher-Shannon information plane analysis of SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series to characterize vegetation recovery after fire disturbance  

Science.gov (United States)

The time dynamics of SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) time series are analyzed by using the statistical approach of the Fisher-Shannon (FS) information plane to assess and monitor vegetation recovery after fire disturbance. Fisher-Shannon information plane analysis allows us to gain insight into the complex structure of a time series to quantify its degree of organization and order. The analysis was carried out using 10-day Maximum Value Composites of NDVI (MVC-NDVI) with a 1 km × 1 km spatial resolution. The investigation was performed on two test sites located in Galizia (North Spain) and Peloponnese (South Greece), selected for the vast fires which occurred during the summer of 2006 and 2007 and for their different vegetation covers made up mainly of low shrubland in Galizia test site and evergreen forest in Peloponnese. Time series of MVC-NDVI have been analyzed before and after the occurrence of the fire events. Results obtained for both the investigated areas clearly pointed out that the dynamics of the pixel time series before the occurrence of the fire is characterized by a larger degree of disorder and uncertainty; while the pixel time series after the occurrence of the fire are featured by a higher degree of organization and order. In particular, regarding the Peloponneso fire, such discrimination is more evident than in the Galizia fire. This suggests a clear possibility to discriminate the different post-fire behaviors and dynamics exhibited by the different vegetation covers.

Lanorte, Antonio; Lasaponara, Rosa; Lovallo, Michele; Telesca, Luciano

2014-02-01

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Method for Tealeaves Quality Estimation Through Measurements of Degree of Polazation, Leaf Area Index, Photosynthesis Available Radiance and Normalized Difference Vegetation Index for Characterization of Tealeaves  

OpenAIRE

Method for tealeaves quality estimation through measurements of Degree of Polarization: DP, Leaf Area Index: LAI, Photosynthesis Available Radiance: PAR and Normalized Difference Vegetation Index: NDVI for characterization of tealeaves is proposed. The method allows estimations of PAR, NDVI, Grow Index: GI by using measured Degree of Polarization: DP of tealeaves. Through experiments at the tea farm areas, it is found that the proposed method is validated. Also, the method is validated throug...

Kohei Arai

2013-01-01

10

Global Trends in Seasonality of Normalized Difference Vegetation Index (NDVI, 1982–2011  

Directory of Open Access Journals (Sweden)

Full Text Available A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA procedure, over half (56.30% of land surfaces were found to exhibit significant trends. Almost half (46.10% of the significant trends belonged to three classes of seasonal trends (or changes. Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing an increase in the amplitude of the annual seasonal signal whereby increases in NDVI in the green season were balanced by decreases in the brown season. These areas were found primarily in grassland and shrubland regions. Class 3 was found primarily in the Taiga and Tundra biomes and exhibited increases in the annual summer peak in NDVI. While no single attribution of cause could be determined for each of these classes, it was evident that they are primarily found in natural areas (as opposed to anthropogenic land cover conversions and that they are consistent with climate-related ameliorations of growing conditions during the study period.

Assaf Anyamba

2013-09-01

11

Use of Normalized Difference Vegetation Index (NDVI) habitat models to predict breeding birds on the San Pedro River, Arizona  

Science.gov (United States)

Successful management practices of avian populations depend on understanding relationships between birds and their habitat, especially in rare habitats, such as riparian areas of the desert Southwest. Remote-sensing technology has become popular in habitat modeling, but most of these models focus on single species, leaving their applicability to understanding broader community structure and function largely untested. We investigated the usefulness of two Normalized Difference Vegetation Index (NDVI) habitat models to model avian abundance and species richness on the upper San Pedro River in southeastern Arizona. Although NDVI was positively correlated with our bird metrics, the amount of explained variation was low. We then investigated the addition of vegetation metrics and other remote-sensing metrics to improve our models. Although both vegetation metrics and remotely sensed metrics increased the power of our models, the overall explained variation was still low, suggesting that general avian community structure may be too complex for NDVI models.

McFarland, Tiffany Marie; van Riper, Charles, III

2013-01-01

12

Models for the prediction of the cetane index of biofuels obtained from different vegetable oils using their fatty acid composition  

International Nuclear Information System (INIS)

The objective of the present work is to obtain a physical-mathematical model that establishes a relationship between the cetane index of biofuels obtained from different vegetable oils and its composition of essential fatty acid. This model is based on experimental data obtained by the authors of the present work and an experimental data reported by different extracted authors of indexed databases. The adjustment of the coefficients of the model is based on the obtaining of residual minima in the capacity of prediction of the model. Starting from these results it is established a very useful tool for the determination of such an important parameter for the fuel diesel as it is the cetane index obtained from an analysis of chemical composition and not obtained from tests in engines banks, to save time and economic resources. (author)

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Classifying cropping area of middle Heihe River Basin in China using multitemporal Normalized Difference Vegetation Index data  

Science.gov (United States)

Accurate information regarding the structure of crops is critical for the improvement and optimization of land surface models. Multitemporal remote sensing imagery is more effective to determine the crop structure than the single-temporal images because they contain phenological information. Crop structure was extracted based on time series of moderate-resolution imaging spectroradiometer (MODIS) data in the middle Heihe River Basin. A time series of Normalized Difference Vegetation Index (NDVI) data with a 3-day temporal resolution was composed based on daily MODIS reflectance products (MOD 09) from January to December 2011. A total of 120 scenes of composited imagery were integrated into an image data cube of NDVI time series, which was used to extract crop structure for the study area. The spectral curves of corn, wheat, rape, vegetables, and other crops are based on both in situ measurements and visual interpretation. The major crop types were classified by using the adaptive boosting (Adaboost) and support vector machine (SVM) algorithms. The results show that the classification accuracy of Adaboost and SVM was 86.01% and 70.28%, respectively, with Kappa coefficients of 0.8351 and 0.6438, respectively. Summarizing the classification methods used in this study effectively characterize the spatial distribution of the main crops.

Han, Huibang; Ma, Mingguo; Wang, Xufeng; Ma, Shoucun

2014-01-01

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Normalized Difference Vegetation Index as a Tool for Wheat Yield Estimation: A Case Study from Faisalabad, Pakistan  

Science.gov (United States)

For estimation of grain yield in wheat, Normalized Difference Vegetation Index (NDVI) is considered as a potential screening tool. Field experiments were conducted to scrutinize the response of NDVI to yield behavior of different wheat cultivars and nitrogen fertilization at agronomic research area, University of Agriculture Faisalabad (UAF) during the two years 2008-09 and 2009-10. For recording the value of NDVI, Green seeker (Handheld-505) was used. Split plot design was used as experimental model in, keeping four nitrogen rates (N1 = 0?kg?ha?1, N2 = 55?kg?ha?1, N3 = 110?kg?ha?1, and N4 = 220?kg ha?1) in main plots and ten wheat cultivars (Bakkhar-2001, Chakwal-50, Chakwal-97, Faisalabad-2008, GA-2002, Inqlab-91, Lasani-2008, Miraj-2008, Sahar-2006, and Shafaq-2006) in subplots with four replications. Impact of nitrogen and difference between cultivars were forecasted through NDVI. The results suggested that nitrogen treatment N4 (220?kg?ha?1) and cultivar Faisalabad-2008 gave maximum NDVI value (0.85) at grain filling stage among all treatments. The correlation among NDVI at booting, grain filling, and maturity stages with grain yield was positive (R2 = 0.90; R2 = 0.90; R2 = 0.95), respectively. So, booting, grain filling, and maturity can be good depictive stages during mid and later growth stages of wheat crop under agroclimatic conditions of Faisalabad and under similar other wheat growing environments in the country. PMID:25045744

Sultana, Syeda Refat; Ali, Amjed; Ahmad, Ashfaq; Mubeen, Muhammad; Zia-Ul-Haq, M.; Ahmad, Shakeel; Ercisli, Sezai; Jaafar, Hawa Z. E.

2014-01-01

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Spatial and Temporal Variation of Normalized Difference Vegetation Index (NDVI and Rainfall in the North East Arid Zone of Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available This study examines the spatial and temporal variation of onset and cessation of rainfall and greenness in the North East Arid Zone of Nigeria. Onset and cessation of greenness dates were determined from mean monthly time series of Normalized Difference Vegetation Index (NDVI using Advance Very High Resolution Radiometer (AVHRR data for five meteorological stations in the zone for a period of nineteen years (1981-1999. Lowest growing days of six weeks were observed in Nguru (12.53°N, 10.28°E, alt.343 m, Potiskum (11.42°N, 11.02°E, alt.415 m and Maiduguri (11.51°N, 13.05°E, alt. 354 m, while Yola (12.28°N, 9.14°E, alt.174 m and Bauchi (10.17°N, 9.49°E, alt.609 m have growing days of 15 and 16 weeks respectively. Highest rate of greenness of 0.18/month was observed inMaiduguriwhile the lowest rate of green-up of 0.07/month was observed in Bauchi. Similarly, highest rate of senescence (0.08/month was observed in Bauchi while lowest rate of senescence (0.04/month was observed in Nguru.

Christiana F. Olusegun

2013-08-01

16

Correlation of meteorological parameters and remotely sensed normalized difference vegetation index (NDVI) with cotton leaf curl virus (CLCV) in Multan  

International Nuclear Information System (INIS)

Climate change and weather has a profound effect on the spread of Cotton Leaf Curl Virus (CLCV) which is transmitted by whitefly. Climate change is altering temperature and precipitation patterns, resulting in the shift of some insect/pest from small population to large population thus effecting crops yield. To find out the relationship between the weather conditions, outburst of CLCV and changes in Normalized Difference Vegetation Index (NDVI) values due to the outburst of CLCV, a study was carried out for tehsil Multan. Data was acquired for the months of June, July, August and September for the year 2010. Regression analysis between CLCV and meteorological conditions as well as between CLCV and NDVI was performed. Meteorological parameters included temperature, humidity, precipitation, cloud cover, wind direction, pan evaporation and sunshine hours. NDVI values were calculated from SPOT satellite imagery (1km) using ArcMap10 and WinDisp v5.1. Correlation coefficients obtained in most of the cases were acceptable however the significance F and P-value were higher than their critical value at 95% level of significance. Therefore significant correlation was found only between CLCV and temperature and between CLCV and PAN evaporation during the month of July.

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Online measurement of soil organic carbon as correlated with wheat normalised difference vegetation index in a vertisol field.  

Science.gov (United States)

This study explores the potential of visible and near infrared (vis-NIR) spectroscopy for online measurement of soil organic carbon (SOC). It also attempts to explore correlations and similarities between the spatial distribution of SOC and normalized differential vegetation index (NDVI) of a wheat crop. The online measurement was carried out in a clay vertisol field covering 10 ha of area in Karacabey, Bursa, Turkey. Kappa statistics were carried out between different SOC and NDVI data to investigate potential similarities. Calibration model of SOC in full cross-validation resulted in a good accuracy (R (2) = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81). The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R (2) = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R (2) = 0.60, RMSEP = 0.20%, and RPD = 1.41). Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map. PMID:25097882

Tekin, Yücel; Ulusoy, Yahya; Tümsava?, Zeynal; Mouazen, Abdul M

2014-01-01

18

Test of Multi-spectral Vegetation Index for Floating and Canopy-forming Submerged Vegetation  

OpenAIRE

Remote sensing of terrestrial vegetation has been successful thanks to the unique spectral characteristics of green vegetation, low reflectance in red and high reflectance in Near-InfraRed (NIR). These spectral characteristics were used to develop vegetation indices, including Normalized Difference Vegetation Index (NDVI). However, the NIR absorption by water and light scattering from suspended particles reduces the practical application of such indices in aquatic vegetation studies, especial...

Philemon Kirui; Harene Natarajan; Hyun Jung Cho

2008-01-01

19

Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI3g at Global Scales  

Directory of Open Access Journals (Sweden)

Full Text Available Satellite observations of surface reflected solar radiation contain information about variability in the absorption of solar radiation by vegetation. Understanding the causes of variability is important for models that use these data to drive land surface fluxes or for benchmarking prognostic vegetation models. Here we evaluated the interannual variability in the new 30.5-year long global satellite-derived surface reflectance index data, Global Inventory Modeling and Mapping Studies normalized difference vegetation index (GIMMS NDVI3g. Pearson’s correlation and multiple linear stepwise regression analyses were applied to quantify the NDVI interannual variability driven by climate anomalies, and to evaluate the effects of potential interference (snow, aerosols and clouds on the NDVI signal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systems where in some regions and seasons > 40% of the NDVI variance could be explained by precipitation anomalies. Temperature correlations were strongest in northern mid- to high-latitudes in the spring and early summer where up to 70% of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America, winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wet season precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

Alvaro Ivanoff

2013-08-01

20

Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales  

Science.gov (United States)

Satellite observations of surface reflected solar radiation contain informationabout variability in the absorption of solar radiation by vegetation. Understanding thecauses of variability is important for models that use these data to drive land surface fluxesor for benchmarking prognostic vegetation models. Here we evaluated the interannualvariability in the new 30.5-year long global satellite-derived surface reflectance index data,Global Inventory Modeling and Mapping Studies normalized difference vegetation index(GIMMS NDVI3g). Pearsons correlation and multiple linear stepwise regression analyseswere applied to quantify the NDVI interannual variability driven by climate anomalies, andto evaluate the effects of potential interference (snow, aerosols and clouds) on the NDVIsignal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systemswhere in some regions and seasons 40 of the NDVI variance could be explained byprecipitation anomalies. Temperature correlations were strongest in northern mid- to-high-latitudes in the spring and early summer where up to 70 of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America,winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wetseason precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

Zeng, Fanwei; Collatz, George James; Pinzon, Jorge E.; Ivanoff, Alvaro

2013-01-01

21

Testing gridded land precipitation data and precipitation and runoff reanalyses (1982-2010) between 45° S and 45° N with Normalized Difference Vegetation Index data  

Science.gov (United States)

The realistic simulation of key components of the land-surface hydrological cycle - precipitation, runoff, evaporation and transpiration - in general circulation models of the atmosphere is crucial to assess adverse weather impacts on environment and society. Here, gridded precipitation data from observations and precipitation and runoff fields from reanalyses were tested with satellite-derived global vegetation index data for 1982-2010 and latitudes between 45° S and 45° N. Data were obtained from the Climate Research Unit (CRU), the Global Precipitation Climatology Project (GPCP) and Tropical Rainfall Monitoring Mission (TRMM; analysed for 1998-2010 only) and (precipitation and runoff) reanalyses were obtained from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), the European Centre for Medium-Range Weather Forecasts (ECMWF) and the NASA Global Modelling and Assimilation Office (GMAO). Annual land-surface precipitation was converted to annual potential vegetation net primary productivity (NPP) and was compared to mean annual Normalized Difference Vegetation Index data measured by the Advanced Very High Resolution Radiometer (1982-1999) and MODIS (2001-2010). The effect of spatial resolution on the agreement between NPP and NDVI was investigated as well. The CRU and TRMM derived NPP agreed most closely with the NDVI data. The GPCP data showed weaker spatial agreement, largely because of their lower spatial resolution, but similar temporal agreement. MERRA Land and ERA Interim precipitation reanalyses showed similar spatial agreement as the GPCP data and good temporal agreement in semi-arid regions of the Americas, Asia, Australia and southern Africa. The NCEP/NCAR reanalysis showed the lowest spatial agreement which could only in part be explained by its lower spatial resolution. No reanalysis showed realistic interannual precipitation variations for northern tropical Africa. Inclusion of runoff in the NPP prediction resulted only in (marginally) better agreement for the MERRA Land reanalysis and worse agreement for the NCEP/NCAR and ERA Interim reanalyses.

Los, S. O.

2014-12-01

22

Using MODIS Normalized Difference Vegetation Index to monitor seasonal and inter-annual dynamics of wetland vegetation in the Great Artesian Basin: a baseline for assessment of future changes in a unique ecosystem  

Science.gov (United States)

The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland area and the discharge associated with individual springs, providing a potential means of monitoring groundwater flow using measurements of wetland area. Previous studies using this relationship to monitor Great Artesian Basin springs have used aerial photography or high resolution satellite images, giving sporadic temporal information. These "snapshot " studies need to be placed within a longer and more regular context to better assess changes in response to aquifer draw-downs. In this study, the potential of medium resolution MODIS Normalized Difference Vegetation Index data for studying the long-term and high frequency temporal dynamics of wetland vegetation at the Dalhousie Spring Complex of the GAB is tested. Photosynthetic activity within Dalhousie wetlands could be differentiated from surrounding land responses. The study showed good correlation between wetland vegetated area and groundwater flow, but also the important influence of natural species phenologies, rainfall, and human activity on the observed seasonal and inter-annual vegetation dynamic. Declining trends in the extent of wetland areas were observed over the 2000- 2009 period followed by a return of wetland vegetation since 2010. This study underlined the need to continue long-term medium resolution satellite studies of the Great Artesian Basin as these data provide a good understanding of variability within the wetlands, give temporal context for less frequent studies and a strong baseline for assessment of future changes.

Petus, C.; Lewis, M.; White, D.

2012-07-01

23

Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales  

OpenAIRE

Satellite observations of surface reflected solar radiation contain information about variability in the absorption of solar radiation by vegetation. Understanding the causes of variability is important for models that use these data to drive land surface fluxes or for benchmarking prognostic vegetation models. Here we evaluated the interannual variability in the new 30.5-year long global satellite-derived surface reflectance index data, Global Inventory Modeling and Mapping Studies normalize...

Alvaro Ivanoff; James Collatz, G.; Fan-Wei Zeng; Pinzon, Jorge E.

2013-01-01

24

Spectral vegetation indexes and the remote sensing of biophysical parameters  

Science.gov (United States)

Combinations of remotely sensed data from different spectral bands have been combined into spectral vegetation indexes (SVIs) and used to determine biophysical parameters. The characteristics of two-band SVIs made up of visible and near-infrared reflectances are examined. Two canopy reflectance models, a turbid media model and a geometrical model, are used to study the effects of different canopy structures on the measurement of leaf area index and the fraction of photosynthetically intercepted active radiation.

Huemmrich, Karl F.; Goward, Samuel N.

1992-01-01

25

Série temporal de índice de vegetação sobre diferentes tipologias vegetais no Rio Grande do Sul / Time series of vegetation index for different vegetation types in Rio Grande do Sul  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com este trabalho objetivou-se identificar a dinâmica fenológica das principais tipologias vegetais do Rio Grande do Sul, para o período de 2000 a 2010, utilizando-se dados de Enhanced Vegetation Index, através da transformada de ondaleta. A identificação da fenologia em ciclos ou padrões sazonais e [...] m séries temporais de índices de vegetação, obtidos por sensores orbitais, permite a observação de anomalias e os efeitos de mudanças climáticas ou ambientais. Um perfil temporal do Enhanced Vegetation Index foi construído para o Rio Grande do Sul e retiradas amostras para quatro tipologias vegetais: campo nativo, floresta ombrófila mista, cultivo de soja e de arroz. Essas amostras foram submetidas à transformada de ondaleta, que permitiu a decomposição da série e apresentação dos dados em relação ao tempo e frequência com que os eventos fenológicos ocorreram. Os dados apresentaram regularidade na dinâmica das tipologias vegetais testadas, com ciclos anuais de maior vigor e crescimento vegetal nas estações de primavera e verão e menor no outono e inverno. Abstract in english The objective of this study was the identification of the phenology dynamics of the main types of vegetation of Rio Grande do Sul state, for the period from 2000 to 2010, using Enhanced Vegetation Index data through the wavelet transform. The identification of cycles or seasonal patterns in time ser [...] ies of vegetation indices obtained by orbital sensors allows the observation of anomalies and effects of climate and environmental change. A temporal profile of Enhanced Vegetation Index was built for the Rio Grande do Sul region, where samples of the four main plant typologies were selected: native grassland, mixed ombrophilous forest, soybean and rice crop. These samples were submitted to the wavelet transform, which allowed the decomposition of the series and presentation of data in relation to time and frequency with which the phenological events have occurred. The data showed regularity in the dynamics of vegetation types tested, with annual cycles of plant growth and higher Enhanced Vegetation Index values in spring and summer and lower Enhanced Vegetation Index values in autumn and winter.

Tatiana M., Kuplich; Andreise, Moreira; Denise C., Fontana.

1116-11-01

26

Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index  

International Nuclear Information System (INIS)

The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow awarming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.

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Seasonal relationship between normalized difference vegetation index and abundance of the Phlebotomus kala-azar vector in an endemic focus in Bihar, India.  

Science.gov (United States)

Remote sensing was applied for the collection of spatio-temporal data to increase our understanding of the potential distribution of the kala-azar vector Phlebotomus argentipes in endemic areas of the Vaishali district of Bihar, India. We produced monthly distribution maps of the normalized difference vegetation index (NDVI) based on data from the thematic mapper (TM) sensor onboard the Landsat-5 satellite. Minimum, maximum and mean NDVI values were computed for each month and compared with the concurrent incidence of kala-azar and the vector density. Maximum and mean NDVI values (R2 = 0.55 and R2 = 0.60, respectively), as well as the season likelihood ratio (X2 = 17.51; P <0.001), were found to be strongly associated with kala-azar, while the correlation with between minimum NDVI values and kala-azar was weak (R2 = 0.25). Additionally, a strong association was found between the mean and maximum NDVI values with seasonal vector abundance (R2 = 0.60 and R2 = 0.55, respectively) but there was only a marginal association between minimum NDVI value and the spatial distribution of kala-azar vis-a?-vis P. argentipes density. PMID:23242680

Bhunia, Gouri S; Kesari, Shreekant; Chatterjee, Nandini; Mandal, Rakesh; Kumar, Vijay; Das, Pradeep

2012-11-01

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Mapeamento do índice de vegetação da diferença normalizada em lavoura de algodão / Mapping of the normalized difference vegetation index in cotton field  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os dados de sensoriamento remoto em campo podem fornecer informações detalhadas sobre a variabilidade de parâmetros biofísicos ligados à produtividade em grandes áreas e apresentam potencial para o monitoramento destes parâmetros, ao longo de todo o ciclo de desenvolvimento da cultura. Este trabalho [...] objetivou mapear a variabilidade espacial do índice de vegetação da diferença normalizada (NDVI) e seus componentes, em duas lavouras comerciais de algodão (Gossipium hirsutum L.), utilizando sensor óptico ativo, em nível terrestre. Os dados foram coletados utilizando-se sensor instalado em um pulverizador autopropelido agrícola. Um receptor GPS foi acoplado ao sensor, para a obtenção das coordenadas dos pontos de amostragem. As leituras foram realizadas em faixas espaçadas em 21,0 m, aproveitando-se as passadas do veículo no momento da pulverização de agroquímicos, e os dados submetidos à análise estatística clássica e geoestatística. Mapas de distribuição espacial das variáveis foram elaborados pela interpolação por krigagem. Observou-se maior variabilidade espacial do NDVI e da reflectância espectral da vegetação na região do infravermelho próximo (IVP) (880 nm) e do visível (590 nm) na lavoura com maior estresse fisiológico, devido ao ataque do percevejo castanho [Scaptocoris castanea (Hem.: Cydnidae)], em relação à lavoura sadia. Abstract in english The remote sensing data obtained at field level can provide detailed information about the variability of biophysical parameters related to yield over large areas, and present potential for monitoring these parameters throughout the crop development cycle. This study aimed to map the spatial variabi [...] lity of the Normalized Difference Vegetation Index (NDVI) and its components in two commercial cotton (Gossipium hirsutum L.) fields, by using an active optical sensor at the ground level. Data were collected with the aid of an optical sensor installed in a self-propelled agricultural sprayer. A GPS receiver was connected to the sensor, in order to obtain the coordinates of the sampling points. The readings were performed in rows spaced 21.0 m apart by the sensor installed on a vehicle, during the spraying operation, and data analyzed by using the classical statistics and geostatistics. Spatial distribution maps of the variables were generated by kriging interpolation. It was observed a higher spatial variability of NDVI and spectral reflectance of vegetation in the region of near infrared (NIR) (880 nm) and visible infrared (590 nm) in the crop with higher physiological stress, due to the brown bug [Scaptocoris castanea (Hem.: Cydnidae)] attack, when compared to the healthy one.

Anamari Viegas de Araujo, Motomiya; José Paulo, Molin; Wagner Rogerio, Motomiya; Fábio Henrique, Rojo Baio.

2012-03-01

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Early Detection of Eruptive Dykes Revealed by Normalized Difference Vegetation Index (NDVI) on Nyiragongo and Etna Volcanoes: Implications for Dyke Wedge Emplacement, Monitoring, and Risk Assessment.  

Science.gov (United States)

Flank-fissure eruptions involve lateral injection and propagation of magma in a volcanic edifice along pre- existing fractures in the direction of a volcanic rift zone (VRZ) where magma intrusion and lava flow production are concentrated over time. Gradual dyke wedge emplacement on volcano flanks and in VRZ's does not necessarily trigger large amplitude deformation signals susceptible to be recorded months or even years before the actual eruption. We show that active and potentially eruptive areas in a VRZ can be detected up to 2 years before the arrival to the surface of the final eruptive dyke and venting of lava flows by processing satellite images applying a Normalized Difference Vegetation Index (NDVI) algorithm. A positive NDVI anomaly is indicative of excessive photosynthetic plant activity. A posteriori analysis of satellite images reveal that a high- NDVI linear anomaly was apparent in vegetated areas of VRZ's on Etna from 2000 to 2002 and on Nyiragongo in June 2001, several months to years before eruptive fractures formed directly above the NDVI anomaly. We propose that the observed NDVI linear anomalies are the signature of the integrated physico-chemical effects (increased heat and CO2 flux, H2O condensation) caused by the structurally-controlled progressive injection and propagation, in a VRZ and a few months to years before the eruption, of a series of dykes (dyke wedge) that did not reach the surface. We focus of Nyiragongo volcano where historical flank-fissure eruptions from lava lake drainage in 1977 and 2002 show a link with tectonics of the Kivu rift (western branch of the East African Rift System). In 2002, dykes were injected in the southern VRZ bounded by Kivu rift normal faults and propagated over 14 km producing lava flows that caused widespread destruction in the city of Goma. Data from Nyiragongo suggest that as a dyke wedge is formed and repeatedly reactivated, final eruptive dykes can be injected easily and can propagate rapidly further along the VRZ impacting populated areas far from the magmatic conduit. This has important implications for understanding the current process of magma convection feeding the active Nyiragongo lava lake as well as potential small-volume lateral magma injections into the reactivated southern VRZ. The NDVI processing methodology has potentially important implications for monitoring networks on deeply vegetated restless volcanoes with limited or difficult access. More importantly, on volcanoes where eruptive style changes from crater-centered to eccentric flank activity or for which new inactive VRZ's could be reactivated towards populated areas, our methodology constitutes a new tool for early detection of potential flank eruptive vents. By improving the understanding of the link between edifice structure and eruptive activity of effusive volcanoes it can significantly improve integrated risk analysis and the effectiveness of early-detection warning systems for populations at risk.

Komorowski, J.; Houlié, N.; Kasereka, C. M.; Ciraba, H.

2006-12-01

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Leaf Area Index derivation from hyperspectral vegetation indices and the red edge position  

OpenAIRE

The aim of this study was to compare the performance of various narrowband vegetation indices in estimating Leaf Area Index (LAI) of structurally different plant species having different soil backgrounds and leaf optical properties. The study uses a dataset collected during a controlled laboratory experiment. Leaf area indices were destructively acquired for four species with different leaf size and shape. Six widely used vegetation indices were investigated. Narrowband vegetation indices inv...

Darvishzadeh, R.; Atzberger, C.; Skidmore, A. K.; Abkar, A.

2009-01-01

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An Assessment of Mining Activities Impact on Vegetation in Bukuru Jos Plateau State Nigeria Using Normalized Differential Vegetation Index (NDVI  

Directory of Open Access Journals (Sweden)

Full Text Available The study area has a pathetic and deplorable condition of landuse/ landcover. The vegetal cover in the area has to be removed from the activities of tin mining which consequently resulted into adverse environmental effect such as erosion. Different forms of human induced stress such as tin mining and heavy rainfall have severely degraded soils on the Jos Plateau. Such degradation problems are also caused by deforestation, inappropriate farming system, bush burning and over-grazing which are hostile to the environment. The impact of tin mining has greatly affected the natural ecology of the study area Bukuru. Micro and macro organisms and plants have been stripped off their natural habitat due to tin mining activities. This paper therefore, assesses the mining activities impact on the vegetation in Bukuru area of Jos plateau in Nigeria. Normalized Differential Vegetation Index (NDVI techniques was adopted to Maps effect of tin mining on the vegetation for the period between 1975 and 2007 using LandSat satellite data. The result of the differential vegetation index analysis reveals a decline in vegetated surfaces in 1986 ranging from 0.04 to 0.58 indicating 0.05 and continuous loss in vegetation over the study area in 2007 (vegetated surface decrease by 0.08 between 1986 and 2007. The decrease in vegetated surface is due to intensive mining and cultivation.

Musa Haruna D.

2011-11-01

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A MODIS-based vegetation index climatology  

Science.gov (United States)

Our motivation here is to provide information for the NASA Soil Moisture Active Passive (SMAP) satellite soil moisture retrieval algorithms (launch in 2014). Vegetation attenuates the signal and the algorithms must correct for this effect. One approach is to use data that describes the canopy water ...

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Assessing intra-annual vegetation regrowth after fire using the pixel based regeneration index  

OpenAIRE

Several remote sensing studies have discussed the potential of satellite imagery as an alternative for extensive field sampling to quantify fire-vegetation impact over large areas. Most studies depend on Landsat image availability with infrequent image acquisition dates and consequently are limited for assessing intra-annual fire-vegetation dynamics or comparing different fire plots and dates. The control pixel based regeneration index (pRI) derived from SPOT-VEGETATION (VGT) normalized diffe...

Lhermitte, S.; Verbesselt, J.; Verstraeten, W. W.; Veraverbeke, S.; Coppin, P.

2011-01-01

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Test of Multi-spectral Vegetation Index for Floating and Canopy-forming Submerged Vegetation  

Directory of Open Access Journals (Sweden)

Full Text Available Remote sensing of terrestrial vegetation has been successful thanks to the unique spectral characteristics of green vegetation, low reflectance in red and high reflectance in Near-InfraRed (NIR. These spectral characteristics were used to develop vegetation indices, including Normalized Difference Vegetation Index (NDVI. However, the NIR absorption by water and light scattering from suspended particles reduces the practical application of such indices in aquatic vegetation studies, especially for the Submerged Aquatic Vegetation (SAV that grows below water surface. We experimentally tested if NDVI can be used to depict canopies of aquatic plants in shallow waters. A 100-gallonoutdoor tank was lined with black pond liners, a black panel or SAV shoots were mounted on the bottom, and filled with water up to 0.5 m. We used a GER 1500 spectroradiometer to collect spectral data over floating waterhyacinth (Eichhornia crassipes and also over the tanks that contain SAV and black panel at varying water depths. The measured upwelling radiance was converted to % reflectance; and we integrated the hyperspectral reflectance to match the Red and NIR bands of three satellite sensors: Landsat 7 ETM, SPOT 5 HRG, and ASTER. NDVI values ranged 0.6-0.65 when the SAV canopy was at the water level, then they decreased linearly (slope of 0.013 NDVI/meter with water depth increases in clear water. When corrected for water attenuation using the data obtained from the black panel, the NDVI values significantly increased at all depths that we tested (0.1 – 0.5 m. Our results suggest the conventional NDVI: (1 can be used to depict SAV canopies at water surface; (2 is not a good indicator for SAV that is adapted to live underwater or other aquatic plants that are submerged during flooding even at shallow waters (0.3 m; and (3 the index values can significantly improve if information on spectral reflectance attenuation caused by water volume increases is collected simultaneously through ground-truthing and integrated.

Philemon Kirui

2008-12-01

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Analysis of Vegetation Index Variations and the Asian Monsoon Climate  

Science.gov (United States)

Vegetation growth depends on local climate. Significant anthropogenic land cover and land use change activities over Asia have changed vegetation distribution as well. On the other hand, vegetation is one of the important land surface variables that influence the Asian Monsoon variability through controlling atmospheric energy and water vapor conditions. In this presentation, the mean and variations of vegetation index of last decade at regional scale resolution (5km and higher) from MODIS have been analyzed. Results indicate that the vegetation index has been reduced significantly during last decade over fast urbanization areas in east China, such as Yangtze River Delta, where local surface temperatures were increased significantly in term of urban heat Island. The relationship between vegetation Index and climate (surface temperature, precipitation) over a grassland in northern Asia and over a woody savannas in southeast Asia are studied. In supporting Monsoon Asian Integrated Regional Study (MAIRS) program, the data in this study have been integrated into Giovanni, the online visualization and analysis system at NASA GES DISC. Most images in this presentation are generated from Giovanni system.

Shen, Sunhung; Leptoukh, Gregory G.; Gerasimov, Irina

2012-01-01

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An evaluation of prediction accuracy and stability of a new vegetation index for estimating vegetation leaf area index  

Science.gov (United States)

LAI is a crucial parameter and a basic quantity indicating crop growth situation. Empirical models comprising spectral indices (SIs) and LAI have widely been applied to the retrieval of LAI. SI method already has exhibited feasibility in the estimation of vegetation LAI. However, it is largely subject to the inconsistency from different remote sensors which have varied specifications, such as spectral response features and central wavelength. To address this issue, a new vegetation index (VIUPD) based on the universal pattern decomposition method was proposed. It is expressed as a linear sum of the pattern decomposition coefficients and features in sensor-independency. The aim of this study was to evaluate the prediction accuracy and stability of VIUPD for estimating LAI, compared with three other common-used SIs. In this study, the measured spectra were resampled to simulated TM multispectral data and Hyperion hyperspectral data respectively, using the Gaussian spectral response function. The three typical SIs chosen were including NDVI, TVI and MCARI, which were constructed with the sensitive bands to the LAI. Finally, the regression equations between four selected SIs and LAI were established. The best index evaluated using the simulated TM data was VIUPD which exhibits the best correlation with LAI (R2=0.92) followed by NDVI (R2=0.80). For the simulated Hyperion data, VIUPD again ranks first with R2=0.89, followed by TVI (R2=0.63). Meanwhile, the consistence of VIUPD also was studied based on simulated TM and Hyperion sensor data and the R2 reached to 0.95. It is demonstrated that VIUPD has the best accuracy and stability to estimate LAI of winter wheat whether using simulated TM data or Hyperion data, which reaffirms that VIUPD is comparatively sensor independent.

Jiang, Hailing; Zhang, Lifu; Yang, Hang; Chen, Xiaoping; Wang, Shudong; Li, Xueke; Liu, Kai

2014-11-01

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a Proposed New Vegetation Index, the Total Ratio Vegetation Index (trvi), for Arid and Semi-Arid Regions  

Science.gov (United States)

Vegetation indices that provide important key to predict amount vegetation in forest such as percentage vegetation cover, aboveground biomass, and leaf-area index. Arid and semi-arid areas are not exempt of this rule. Arid and semi-arid areas of northeast Iran cover about 3.4 million ha and are populated by two main tree species, the broadleaf Pistacia vera (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environmentally important but also genetically essential as seed sources for pistachio production in orchards. We investigated the relationships between tree density and vegetation indices in the arid and semi-arid regions in the northeast of Iran by analysing Advanced Land Observing Satellite (ALOS) data PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, and has one band with a wavelength of 0.52-0.77 ?m (JAXA EORC). AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, and has four multispectral bands: blue (0.42-0.50 ?m), green (0.52-0.60 ?m), red (0.61-0.69 ?m), and near infrared (0.76-0.89 ?m) (JAXA EORC). In this study, we estimated various vegetation indices using maximum filtering algorithm (5×5) and examined. This study carried out of juniper forests and natural pistachio stand using Advanced Land Observing Satellite (ALOS) and field inventories. Have been compared linear regression model of vegetation indices and proposed new vegetation index for arid and semi-arid regions. Also, we estimated the densities of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. We present a new vegetation index for arid and semi-arid regions with sparse forest cover, the Total Ratio Vegetation Index (TRVI), and we investigate the relationship of the new index to tree density by analysing data from the Advanced Land Observing Satellite (ALOS) using 5×5 maximum filtering algorithms. The results for pistachio forest showed the coefficient regression of NDVI, SAVI, MSAVI, OSAVI, and TRVI were (R2= 0.68, 0.67, 0.68, 0.68, and 0.71) respectively. The results for juniper forest showed the coefficient regression of NDVI, SAVI, MSAVI, OSAVI, and TRVI were (R2= 0.51, 0.52, 0.51, 0.52, and 0.56) respectively. I hope this research can provide decision of managers to helping sustainable management for arid and semi-arid regions in Iran.

Fadaei, H.; Suzuki, R.; Sakai, T.; Torii, K.

2012-07-01

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Radiative transfer in shrub savanna sites in Niger: Preliminary results from HAPEX-Sahel. Part 3: Optical dynamics and vegetation index sensitivity to biomass and plant cover  

Science.gov (United States)

A shrub savannah landscape in Niger was optically characterized utilizing blue, green, red and near-infrared wavelengths. Selected vegetation indices were evaluated for their performance and sensitivity to describe the complex Sahelian soil/vegetation canopies. Bidirectional reflectance factors (BRF) of plants and soils were measured at several view angles, and used as input to various vegetation indices. Both soil and vegetation targets had strong anisotropic reflectance properties, rendering all vegetation index (6) responses to be a direct function of sun and view geometry. Soil background influences were shown to alter the response of most vegetation indices. N-space greenness had the smallest dynamic range in VI response, but the n-space brightness index provided additional useful information. The global environmental monitoring index (GEMI) showed a large 6 dynamic range for bare soils, which was undesirable for a vegetation index. The view angle response of the normalized difference vegetation index (NDVI), atmosphere resistant vegetation index (ARVI) and soil atmosphere resistant vegetation index (SARVI) were asymmetric about nadir for multiple view angles, and were, except for the SARVI, altered seriously by soil moisture and/or soil brightness effects. The soil adjusted vegetation index (SAVI) was least affected by surface soil moisture and was symmetric about nadir for grass vegetation covers. Overall the SAVI, SARVI and the n-space vegetation index performed best under all adverse conditions and were recommended to monitor vegetation growth in the sparsely vegetated Sahelian zone.

vanLeeuwen, W. J. D.; Huete, A. R.; Duncan, J.; Franklin, J.

1994-01-01

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A special vegetation index for the weed detection in sensor based precision agriculture.  

Science.gov (United States)

Many technologies in precision agriculture (PA) require image analysis and image- processing with weed and background differentiations. The detection of weeds on mulched cropland is one important image-processing task for sensor based precision herbicide applications. The article introduces a special vegetation index, the Difference Index with Red Threshold (DIRT), for the weed detection on mulched croplands. Experimental investigations in weed detection on mulched areas point out that the DIRT performs better than the Normalized Difference Vegetation Index (NDVI). The result of the evaluation with four different decision criteria indicate, that the new DIRT gives the highest reliability in weed/background differentiation on mulched areas. While using the same spectral bands (infrared and red) as the NDVI, the new DIRT is more suitable for weed detection than the other vegetation indices and requires only a small amount of additional calculation power. The new vegetation index DIRT was tested on mulched areas during automatic ratings with a special weed camera system. The test results compare the new DIRT and three other decision criteria: the difference between infrared and red intensity (Diff), the soil-adjusted quotient between infrared and red intensity (Quotient) and the NDVI. The decision criteria were compared with the definition of a worse case decision quality parameter Q, suitable for mulched croplands. Although this new index DIRT needs further testing, the index seems to be a good decision criterion for the weed detection on mulched areas and should also be useful for other image processing applications in precision agriculture. The weed detection hardware and the PC program for the weed image processing were developed with funds from the German Federal Ministry of Education and Research (BMBF). PMID:16917726

Langner, Hans-R; Böttger, Hartmut; Schmidt, Helmut

2006-06-01

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Validating a Dynamic Global Vegetation Model with Remotely Sensed Vegetation Index  

Directory of Open Access Journals (Sweden)

Full Text Available The present study aims to evaluate the ability of IBIS model to capture the difference in vegetation characteristics among six major biomes in the Northeast China Transect and to calibrate the simulated LAI by IBIS, using the product of MODIS LAI (Leaf Area Index. The results showed that IBIS simulated a little lower growing season LAI over temperate evergreen conifer forest and boreal evergreen forest, while it overestimated LAI relative to MODIS in non-growing season. IBIS performed poorly on LAI over savanna, grassland and shrub land, compared with MODIS and it nearly simulated higher LAI throughout the year. Based on regression analysis, the simulating LAI by IBIS (Integrated Biosphere Simulator presented a significant linear correlation with that from MODIS over temperate evergreen conifer forest in spring and winter, boreal evergreen forest throughout the year and grassland from summer to early autumn. Therefore, it was help to adjust the model parameters over these plant functional types to calibrate the estimated LAI in a large spatial scale.

Jiaxin Jin

2013-02-01

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Multisensor reflectance and vegetation index comparisons of Amazon tropical forest phenology with hyperspectral Hyperion data  

Science.gov (United States)

Current earth observing satellite sensors have different temporal, spectral and spatial characteristics that present problems in the establishment of long term, time series data records. Vegetation indices (VI's) are commonly used in deriving long term measures of vegetation biophysical properties, which have been shown useful in interannual climate studies and phenology studies. While significant improvements have been made with new sensors, and algorithms, and processing methods, backward compatibility of VI's is desired so that the long term record can extend back and utilize the AVHRR record to 1981. Conversely, any reprocessing of the AVHRR record should consider steps to allow forward compatibility with newer sensors and products. In this study we evaluated the use of sensor-specific enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) data sets, using a time sequence of Hyperion images over Tapajos National Forest in Brazil over the 2001 and 2002 dry seasons. We computed NDVI, EVI, and a 2-band version of EVI (EVI2) for different sensor systems (AVHRR, MODIS, VIIRS, SPOT-VGT, and SeaWiFS) and evaluated their differences and continuity in the characterization of tropical forest phenology. We also analyzed the influence of different atmosphere correction scenarios to assess noise in the phenology signal. Our analyses show that EVI2 maintains the desirable properties of increased sensitivity in high biomass forests across all sensor systems evaluated in this study. We further conclude that EVI2 can be extended to the AVHRR time series record and compliment that current NDVI time series record.

Kim, Youngwook; Huete, Alfredo R.; Jiang, Zhangyan; Miura, Tomoaki

2007-09-01

42

Assessment of regional biomass-soil relationships using vegetation indexes  

Science.gov (United States)

The development of photosynthetic active biomass in different ecological conditions, as indicated by normalized difference vegetation indices (NDVIs) is compared by performing a stratified sampling (based on soil assocations) on data acquired over Indiana. Data from the NOAA-10 AVHRR were collected for the 1987 and 1988 growing seasons. An NDVI transformation was performed using the two optical bands of the sensor (0.58-0.68 microns and 0.72-1.10 microns). The NDVI is related to the amount of active photosynthetic biomass present on the ground. Samples of NDVI values over 45 fields representing eight soil associations throughout Indiana were collected to assess the effect of soil conditions and acquisition date on the spectral response of the vegetation, as shown by the NDVIs. Statistical analysis of results indicate that land-cover types (forest, forest/pasture, and crops), soil texture, and soil water-holding capacity have an important effect on vegetation biomass changes as measured by AVHRR data. Acquisition dates should be selected with condideration of the phenological stages of vegetation. Sampling of AVHRR data over extended areas should be stratified according to physiographic units rather than man-made boundaries. This will provide more homogeneous samples for statistical analysis.

Lozano-Garcia, D. Fabian; Fernandez, R. Norberto; Johannsen, Chris J.

1991-01-01

43

Heterogeneity as an index of anthropogenic disturbance of soil and vegetation in urban Parks  

Science.gov (United States)

The conditions of urban ecosystems depend on a wide range of anthropogenic factors, one of which is visitor pressure on urban parks. This study aims: (1) to analyze soil properties and vegetation characteristics of different open areas, and (2) to determine an index of disturbance for these areas, according to their spatial heterogeneity. The study was conducted in Tel-Aviv, and addressed two scales: (1) Land Use Units (municipal parks and vacant lots); and (2) Microenvironment (under tree, under bush, herbaceous area, lawn, and path). In each type of microenvironment, soil was sampled at seven points, from layers at two depths (0-2 and 5-10 cm). Before the sampling, penetration depth, litter biomass and vegetation characteristics (vegetation cover, number of species, and vegetation height) were determined in the field. In each soil sample gravimetric soil moisture and organic matter contents were determined, and pH, electrical conductivity and soluble-ion contents were measured in a 1:1 water extraction. The level of disturbance by visitors was scored for each microenvironment according to field evidence of trampling, such as lack of vegetation cover and litter biomass. The results show strong differences in soil properties among the various microenvironments: penetration depth ranged from a few millimeters up to ~ 3 cm; organic matter content from less than 1% to 10%; soil moisture content from a few percents to ~ 30%; electrical conductivity from ~ 0.3 to ~2 dS/m; sodium content from ~ 1 to 7.5 meq/kg; chlorine content from ~ 0.5 to ~9 meq/kg; and litter biomass from 0.5 to 1.4 kg/m2. The vegetation characteristics also varied among the microenvironments: vegetation cover ranged from 11 to 99 %; number of species from 2 to11; and vegetation height from 5 to 35 cm. In order to assess the level of heterogeneity of soil and vegetation, an integral index, based on the number of Duncan groups, has been calculated. Regarding the Scale of Land Use unit, it was found that the highest heterogeneity of soil characteristics corresponded with the lowest species richness. For the smaller-scale unit - Microenvironment - an index was developed that defines the status of disturbance, and it was used to sort the microenvironments into several groups. High correlation between percentiles and averages of soil properties was found for the microenvironments. This hints at a fractal structure of soil properties distribution at the microenvironment level.

Zhevelev, H.; Sarah, P.

2012-04-01

44

Analysis of agricultural drought using vegetation temperature condition index (VTCI) from Terra/MODIS satellite data.  

Science.gov (United States)

The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use of combination of surface temperature and NDVI which provides vegetation and moisture conditions simultaneously. Since drought stress effects on agriculture are closely linked to actual evapotranspiration, we used a vegetation temperature condition index (VTCI) which is more closely related to crop water status and holds a key place in real-time drought monitoring and assessment. In this study, NDVI and land surface temperature (T (s)) from MODIS 8-day composite data during cloud-free period (September-October) were adopted to construct an NDVI-T (s) space, from which the VTCI was computed. The crop moisture index (based on estimates of potential evapotranspiration and soil moisture depletion) was calculated to represent soil moisture stress on weekly basis for 20 weather monitoring stations. Correlation and regression analysis were attempted to relate VTCI with crop moisture status and crop performance. VTCI was found to accurately access the degree and spatial extent of drought stress in all years (2000, 2002, and 2004). The temporal variation of VTCI also provides drought pattern changes over space and time. Results showed significant and positive relations between CMI (crop moisture index) and VTCI observed particularly during prominent drought periods which proved VTCI as an ideal index to monitor terminal drought at regional scale. VTCI had significant positive relationship with yield but weakly related to crop anomalies. Duration of terminal drought stress derived from VTCI has a significant negative relationship with yields of major grain and oilseeds crops, particularly, groundnut. PMID:22200944

Patel, N R; Parida, B R; Venus, V; Saha, S K; Dadhwal, V K

2012-12-01

45

Effects of different vegetable dust exposures1  

Science.gov (United States)

Vali?, F., and Žuškin, E. (1972).Brit. J. industr. Med.,29, 293-297. Effects of different vegetable dust exposures. In order to establish the rank of biological activity of vegetable dusts, five groups of non-smoking female workers exposed to similar concentrations of hemp, flax, cotton, sisal, and jute airborne dust, respectively, were compared as to the prevalence of byssinosis, chronic respiratory symptoms, and one-second expiratory volume changes over the Monday shift. The groups were selected in such a way as to differ in the distribution of age and length of exposure to the respective dust as little as possible. The prevalence of byssinosis in hemp and flax workers was approximately equal (44% and 43% respectively), in cotton workers it was considerably lower (27%), while no byssinosis was caused by either sisal or jute dust. The highest prevalence of other chronic respiratory symptoms was recorded in hemp workers (39%), followed by flax (36%) and cotton workers (27%), while in sisal (13%) and jute workers (13%) it was the lowest. Significant mean FEV1·0 reductions over the shift were recorded in all the groups of textile workers with the largest reductions in hemp workers (19%) followed by flax (11%), cotton (8%), sisal (7%), and jute workers (5%). The application of orciprenaline before the shift diminished the mean acute FEV1·0 falls over the work shift in all the groups studied. PMID:5044600

Vali?, F.; Žuškin, E.

1972-01-01

46

Vegetation Phenology and Vegetation Index Products from Multiple Long Term Satellite Data Records  

Science.gov (United States)

Phenology is the expression of the seasonal cycle of all biotic processes. It is the pulse of our planet, and is an essential and critical component of environmental science influencing biodiversity, species interactions, their ecological functioning, and their effects on fluxes of water, energy, and biogeochemical elements at various scales. Changes in phenology depict an integrated response to environmental change and provide valuable information for global change research, land degradation studies, integrated pest and invasive species management, drought monitoring, wildfire risk assessment, and agricultural production. In this NASA Making Earth System data records for Use in Research Environments (NASA-MEaSUREs) project our multi-institution team of investigators plans to generate a seamless and consistent sensor independent Earth System Data Record and Climate Data Record (ESDR/CDR) quality measures of landscape phenology and vegetation index (VI), by fusing measurements from different satellite missions and sensors. We plan to use the AVHRR, MODIS and VIIRS daily surface reflectance products and design sensor independent algorithms that can be applied to these multi-sensor data sets. Our project aims at generating, documenting, and delivering 30+ years of consistent and well characterized ESDR/CDR quality daily measurements of land surface VI and annual phenology parameters at a climate modeling grid resolution (CMG, 0.05 deg). In collaboration with the newly established USA national phenology network (USA-NPN), we plan to correlate these remote sensing based measurements of phenology and VI with ground observations. We aim at evaluating the consistency and accuracy of these products by comparing them with in situ growing season phenology observations over different biomes, latitudinal and elevational gradients. We plan to distribute these products through the USGS EROS center and support them via a web based interactive visualization system. We will enlist key science and modeling community users, as well as the USA-NPN, in the process of evaluating the merits of these ESDR/CDR products. A user working group (UWG) will advise this effort and link it with the wider national and international user and scientific communities.

Didan, K.; van Leeuwen, W.; Miura, T.; Friedl, M.; Zhang, X.; Czapla-Myers, J.; Jenkerson, C. B.; Maiersperger, T. K.

2008-12-01

47

Sensitivity of leaf chlorophyll concentration of a broad-ban vegetation index at the canopy scale  

International Nuclear Information System (INIS)

The development from a field spectrometric experiment of the chlorophyll vegetation index (CVI), a broad-band 6. sensitive to leaf chlorophyll concentration at the canopy scale, and of its optimized version (OCVI) are described. A single correction factor is incorporated in the OCVI algorithm to take into account the different spectral behaviours due to crop and soil types, sensor spectral resolution and scene sun zenith angle. The sensitivity of different broad-band 6., including CVI, to leaf cholophyll concentration is compared for a wide range of soils and crops conditions and for different sun zenith angles by the analysis of a PROSPECT+SAILH syntetic dataset

48

Different techniques of multispectral data analysis for vegetation fraction retrieval  

Science.gov (United States)

Vegetation monitoring is one of the most important applications of remote sensing technologies. In respect to farmlands, the assessment of crop condition constitutes the basis of growth, development, and yield processes monitoring. Plant condition is defined by a set of biometric variables, such as density, height, biomass amount, leaf area index, and etc. The canopy cover fraction is closely related to these variables, and is state-indicative of the growth process. At the same time it is a defining factor of the soil-vegetation system spectral signatures. That is why spectral mixtures decomposition is a primary objective in remotely sensed data processing and interpretation, specifically in agricultural applications. The actual usefulness of the applied methods depends on their prediction reliability. The goal of this paper is to present and compare different techniques for quantitative endmember extraction from soil-crop patterns reflectance. These techniques include: linear spectral unmixing, two-dimensional spectra analysis, spectral ratio analysis (vegetation indices), spectral derivative analysis (red edge position), colorimetric analysis (tristimulus values sum, chromaticity coordinates and dominant wavelength). The objective is to reveal their potential, accuracy and robustness for plant fraction estimation from multispectral data. Regression relationships have been established between crop canopy cover and various spectral estimators.

Kancheva, Rumiana; Georgiev, Georgi

2012-07-01

49

Spatio-temporal patterns in vegetation start of season across the island of Ireland using the MERIS Global Vegetation Index  

Science.gov (United States)

Spring phenophases such as the beginning of leaf unfolding, measured in the Irish gardens of the International Phenological Garden (IPG) network, indicate an earlier spring occurrence hence a longer growing season. However, these measurements are limited to selected species of trees at a few point locations in the southern half of the country. The aim of this study was to develop a methodology, based on satellite remote sensing, to measure the vegetation start of season (SOS) across the whole island of Ireland on an annual basis, complementary to existing ground-based methods. The SOS metric was extracted for each year in a 7-year time series of 10-day composited, 1.2 km reduced resolution MERIS Global Vegetation Index (MGVI) data from 2003 to 2009, based on curve fitting, using the time series analysis software, TIMESAT. Spatio-temporal variability in the SOS was detected across the island on an annual basis and highlighted in a series of anomaly images showing variation from the 7-year mean SOS. The 2006 SOS was late across the island while there were strong geographical gradients to the SOS anomalies in 2009 when it occurred later in the south and earlier in the north. There was a mix of early and late anomaly values throughout the country in the other years. Qualitatively, the spatial patterns in the timing of the SOS were related to the distribution of landcover types as indicated by the CORINE Land Cover map (CLC). Three statistically separable groups of CLC classes were derived from differences in the SOS, namely agricultural and forest land cover types, peat bogs, and natural and semi-natural vegetation types. These groups demonstrated that vegetation in cultivated areas like pastures has a significantly earlier SOS than in areas of unmanaged vegetation such as peat bogs. An initial climate analysis indicated that an anomalously cold winter and spring in 2005/2006 delayed the 2006 SOS countrywide; while a cold winter followed by a mild spring in 2009 caused considerable spatial variability in the 2009 SOS across the country, ranging from later SOS in the south to early SOS in the north. This study has demonstrated the utility of 10-day MGVI composites for derivation of an SOS metric which can be used as an indicator of spatial variability in vegetation seasonality and has highlighted how SOS varies according to landcover type. The availability of longer time series in the future will allow more focused studies on the sensitivity of the SOS metric to changes in climate as well as short term weather events.

O'Connor, Brian; Dwyer, Edward; Cawkwell, Fiona; Eklundh, Lars

2012-03-01

50

[Characteristics of soil nematode communities in coastal wetlands with different vegetation types].  

Science.gov (United States)

An investigation was conducted on the characteristics of soil nematode communities in different vegetation belts (Spartina alterniflora belt, Sa; Suaeda glauca belt, Sg; bare land, B1; Phragmites australis belt, Pa; and wheat land, Wl) of Yancheng Wetland Reserve, Jiangsu Province of East China. A total of 39 genera and 20 families of soil nematodes were identified, and the individuals of dominant genera and common genera occupied more than 90% of the total. The total number of the nematodes differed remarkably with vegetation belts, ranged from 79 to 449 individuals per 100 grams of dry soil. Wheat land had the highest number of soil nematodes, while bare land had the lowest one. The nematode ecological indices responded differently to the vegetation belts. The Shannon index (H) and evenness index (J) decreased in the order of Pa > Sg > Wl > Sa > Bl, and the dominance index (lambda) was in the order of Bl > Sa > Wl > Sg > Pa, suggesting that the diversity and stability of the nematode community in bare land were lower than those in the other vegetation belts, and the nematode community in the bare land tended to be simplified. The maturity index (MI) was higher in uncultivated vegetation belts than in wheat land, suggesting that the wheat land was disturbed obviously. The nematode community structure differed significantly with vegetation belts, and the main contributing species in different vegetation belts also differed. There existed significant correlations between the soil physical and chemical characteristics and the nematode numbers, trophic groups, and ecological indices. Our results demonstrated that the changes of soil nematode community structure could be used as an indicator well reflecting the diversity of vegetation belt habitat, and an important bio-indicator of coastal wetland ecosystem. PMID:23431791

Liu, Bei-Bei; Ye, Cheng-Long; Yu, Li; Jiao, Jia-Guo; Liu, Man-Qiang; Hu, Feng; Li, Hui-Xin

2012-11-01

51

Recent Trends in Satellite Vegetation Index Observations Indicate Decreasing Vegetation Biomass in the Southeastern Saline Everglades Wetlands  

Science.gov (United States)

We analyzed trends in time series of the normalized difference vegetation index (NDVI) from multitemporal satellite imagery for 2001-2010 over the southeastern Everglades where major changes in vegetation structure and type have been associated with sea-level rise and reduced freshwater flow since the 1940s. Non-parametric trend analysis using the Theil-Sen slope revealed that 84.4% of statistically significant trends in NDVI were negative, mainly concentrated in scrub mangrove, sawgrass (Cladium jamaicense) and spike rush (Eleocharis cellulosa) communities within 5 km of the shoreline. Observed trends were consistent with trends in sawgrass biomass measurements made from 1999-2010 in three Long-term Ecological Research (LTER) sites within our study area. A map of significant trends overlaid on a RapidEye high-resolution satellite image showed large patches of negative trends parallel to the shoreline in and around the 'white zone,' which corresponds to a low-productivity band that has moved inland over the past 70 years. Significantly positive trends were observed mainly in the halophytic prairie community where highly salt tolerant species are typically found. Taken as a whole, the results suggest that increased saline intrusion associated with sea-level rise continues to reduce the photosynthetic biomass within freshwater and oligohaline marsh communities of the southeastern Everglades. Trends in 2001-2010 NDVI in southern saline Everglades wetlands of South Florida. a) slope values; b) areas of significant slope; c) location of the study area.

Fuller, D. O.

2013-12-01

52

Vegetation index correction to reduce background effects in orchards with high spatial resolution imagery  

Science.gov (United States)

High spatial resolution satellite imagery provides an alternative for time consuming and labor intensive in situ measurements of biophysical variables, such as chlorophyll and water content. However, despite the high spatial resolution of current satellite sensors, mixtures of canopies and backgrounds will be present, hampering the estimation of biophysical variables. Traditional correction methodologies use spectral differences between canopies and backgrounds, but fail with spectrally similar canopies and backgrounds. In this study, the lack of a generic solution to reduce background effects is tackled. Through synthetic imagery, the mixture problem was demonstrated with regards to the estimation of biophysical variables. A correction method was proposed, rescaling vegetation indices based on the canopy cover fraction. Furthermore, the proposed method was compared to traditional background correction methodologies (i.e. soil-adjusted vegetation indices and signal unmixing) for different background scenarios. The results of a soil background scenario showed the inability of soil-adjusted vegetation indices to reduce background admixture effects, while signal unmixing and the proposed method removed background influences for chlorophyll (?R2 = ~0.3; ?RMSE = ~1.6 ?g/cm2) and water (?R2 = ~0.3; ?RMSE = ~0.5 mg/cm2) related vegetation indices. For the weed background scenario, signal unmixing was unable to remove the background influences for chlorophyll content (?R2 = -0.1; ?RMSE = -0.6 ?g/cm 2 ), while the proposed correction method reduced background effects (?R2= 0.1; ?RMSE = 0.4 ?g/cm2). Overall, the proposed vegetation index correction method reduced the background influence irrespective of background type, making useful comparison between management blocks possible.

Van Beek, Jonathan; Tits, Laurent; Somers, Ben; Deckers, Tom; Janssens, Pieter; Coppin, Pol

2014-10-01

53

Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index  

OpenAIRE

Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorith...

Scott, Russell L.; Uyen Nguyen; Glenn, Edward P.; Nagler, Pamela L.; Tanya Doody

2013-01-01

54

Predictability of leaf area index using vegetation indices from multiangular CHRIS/PROBA data over eastern China  

Science.gov (United States)

This study analyzed the predictability of leaf area index (LAI) to the variation of vegetation type, observation angle, and vegetation index (VI). The analysis was conducted by using the R2 of the LAI-VI models between in situ measured LAIs and VIs derived from CHRIS/PROBA data. The results show that the discrepancy of vegetation type mostly influences the LAI-VI models. The predictability of LAI to the variation of both vegetation type and index demonstrates the differences of oblique/vertical and backward/forward observations, and backward series are greater than the forward. The predictabilities of LAI to the variation of observation angle are greatest for the soil-adjusted VIs and least for the traditional ratio-based indices. Multivariable linear modeling with all VIs from all five angles yields acceptable accuracy except for the sparse shrub. The backward less-oblique observation (-36 deg) is the only angle chosen in the modeling for grass, shrub, and broad leaf forest, while the nadir view performs best for forests with coniferous trees. These results provide a reference to multiangular LAI estimation for different vegetation communities. VIs accounting for angular soil effects require further investigation in the future.

Gu, Zhujun; Sanchez-Azofeifa, G. Arturo; Feng, Jilu; Cao, Sen

2015-01-01

55

Detection of Terrestrial Ecosystem Disturbances Using Aqua/MODIS Land Surface Temperature and Enhanced Vegetation Index  

Science.gov (United States)

Global information on the timing, location and magnitude of large-scale ecosystem disturbance events is needed to reduce significant uncertainty in the global carbon cycle. The MODIS Global Disturbance Index (MGDI) algorithm is designed for systematic, global, disturbance mapping using Aqua/MODIS Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI) data. The MGDI uses annual maximum composite LST data to detect fundamental changes in land-surface energy partitioning, while avoiding the high natural variability associated with tracking LST at daily, weekly, or seasonal time frames. LST and EVI respond to different biophysical processes and coupling these variables together into a ratio results in a dynamic approach that measures both the energy exchange consequence and the vegetation density changes resulting from disturbance. This robust radiometric relationship is revisited for each individual pixel every year resulting in a consistent methodology that can be generalized globally to provide 1-km resolution information about the effects of major disturbance on woody ecosystems and has been validated across North America. We have now applied the full Aqua/MODIS dataset through 2010 to the MGDI algorithm across woody ecosystems globally and continue to validate the MGDI results by comparison with confirmed, historical disturbance events such as wildfire, hurricanes, insect epidemics, ice storms, and droughts.

Mildrexler, D. J.; Zhao, M.; Running, S. W.

2011-12-01

56

Monitoring Thermal Status of Ecosystems with MODIS Land-Surface Temperature and Vegetation Index Products  

Science.gov (United States)

The global land-surface temperature (LST) and normalized difference vegetation index (NDVI) products retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) data in 2001 were used in this study. The yearly peak values of NDVI data at 5km grids were used to define six NDVI peak zones from -0.2 to 1 in steps of 0.2, and the monthly NDVI values at each grid were sorted in decreasing order, resulting in 12 layers of NDVI images for each of the NDVI peak zones. The mean and standard deviation of daytime LSTs and day-night LST differences at the grids corresponding to the first layer of NDVI images characterize the thermal status of terrestrial ecosystems in the NDVI peak zones. For the ecosystems in the 0.8-1 NDVI peak zone, daytime LSTs distribute from 0-35 C and day-night LST differences distribute from -2 to 22 C. The daytime LSTs and day-night LST differences corresponding to the remaining layers of NDVI images show that the growth of vegetation is limited at low and high LSTs. LSTs and NDVI may be used to monitor photosynthetic activity and drought, as shown in their applications to a flood-irrigated grassland in California and an unirrigated grassland in Nevada.

Wan, Zhengming

2002-01-01

57

Cooling parameters for fruits and vegetables of different sizes in a hydrocooling system  

Directory of Open Access Journals (Sweden)

Full Text Available The cooling of fruits and vegetables in hydrocooling system can be a suitable technique. This work aimed to define cooling time for fruits and vegetables of different sizes, presenting practical indexes that could be used to estimate cooling time for produce with similar characteristics. Fruits (orange melon-Cucumis melo, mango-Mangifera indica, guava-Psidium guajava, orange-Citrus sinensis Osbeck, plum-Prunus domestica, lime-Citrus limon, and acerola-Prunus cerasus and vegetables (cucumber-Cucumis sativus, carrot-Daucus carota, and green bean-Phaseolus vulgaris, were cooled in a hydrocooling system at 1°C. The volume of fruits and vegetables ranged between 8.18 cm³ and 1,150.35 cm³, and between 13.06 cm³ and 438.4 cm³, respectively. Cooling time varied proportionally to produce volume (from 8.5 to 124 min for fruits, and from 1.5 to 55 min, for vegetables. The relationship between volume and time needed to cool fruits (from 1.03 min cm-3 to 0.107 min cm-3 and vegetables (from 0.06 min cm-3 to 0.12 min cm-3 is an index that could be used to estimate cooling time for fruits and vegetables with similar dimensions as those presented in this work.

Teruel Bárbara

2004-01-01

58

Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index  

Directory of Open Access Journals (Sweden)

Full Text Available Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa based on the Enhanced Vegetation Index (EVI from the Moderate Resolution Imaging Spectrometer (MODIS sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo. The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 ? e?bEVI ? c], where the term (1 ? e?bEVI is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73. It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89 difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

Russell L. Scott

2013-08-01

59

The effect of bi-directional reflectance distribution function on the estimation of vegetation indices and leaf area index (LAI): A case study of the vegetation in succession stages after forest fire in northwestern Canada  

International Nuclear Information System (INIS)

The effect of the dependence of the satellite data on sun/sensor geometry must be considered in the case of monitoring vegetation from satellites. Vegetation structure causes uneven scattering of sunlight, which is expressed by bi-directional reflectance distribution function (BRDF). The purpose of this study is to estimate the effect of BRDF of monitoring vegetation using the reflectance of visible and near-infrared bands. We investigated the vegetation in succession stages after forest fire (main species: spruce) in the northwestern Canada. BRF (Bidirectional Reflectance Factor) was measured in the seven sites of some succession stages, along with the measurements of leaf area index (LAI) and biomass. The main results obtained in this study are summarized as follows. (1) In each site, the difference of Normalized Difference Vegetation Index (NDVI) value around 0.1-0.2 was caused by BRDF when the sensor angle was changed from -15deg to 15 deg, being equivalent to the standard image of IKONOS. Also, LAI estimated by NDVI varied from 22% to 65% of the average. (2) The robustness of other vegetation indices to BRDF was compared. The reflectance of the near-infrared band normalized by the sum of other bands (nNIR), and Global Environmental Monitoring Index (GEMI) were investigated along with NDVI. It is clarified that nNIR was most robust in the site where vegetation existed. GEMI was most robust in the sites of scarce vegetation, while NDVI was strongly affected by BRDF in such sites

60

Evaluation of digital hemispherical photography and plant canopy analyser for measuring Vegetation area index of orange orchards  

OpenAIRE

This study presents the results of an evaluation of two indirect methods (Plant Canopy Analyser (PCA) and hemispherical photographs) for measuring vegetation area index VAI of two orange orchards, differing by their ground fraction cover (fc). The evaluation is based on reference data obtained by destructive measurements on limited samples, which allow to calibrate and validate an exponential relationship between the diameter of branches and associated areas of leaves (R2 = 0.99). The obtaine...

Khabba, S.; Duchemin, Benoi?t; Hadria, R.; Ezzahar, J.; Chehbouni, A.; Lahrouni, A.; Hanich, L.

2009-01-01

61

RELATIONSHIP BETWEEN REDNESS INDEX OF SOIL AND CARBON STOCK OF AERIAL BIOMASS IN CERRADO VEGETATION  

Directory of Open Access Journals (Sweden)

Full Text Available http://dx.doi.org/10.5902/1980509812362The color variety of soil is response of its physical, chemical, biological and mineralogical composition. The Munsell color system is based on an objective color evaluation in which it is possible to evaluate different color soil factors such as the presence of iron oxides, particle size, and accumulated organic material. The objective of this study was to identify the relation between the redness index (IAV of soil and the amount of carbon content present in the aerial part of Cerrado vegetation. The study was conducted in seven cities in western Bahia state, in native areas of Cerrado. The determination o soil color was made in the field, with moist soil samples, using the Munsell color chart. From the evaluation of hue, value and chroma, the redness index (IAV was calculated. The estimation of carbon stock above ground was carried out from: trunk and branches, both living and dead trees by the allometric equation developed in Cerrado areas. The redness index of soil, from the layer 0.00 to 0.20 m, has a significant and directly proportional relationship with the carbon stock of above ground biomass of Cerrado vegetation. This may be extrapolated to calculate the carbon stock (EC by the redness index (IAV of soil by the equation [EC = 0.4936 · IAV + 4.2286 (-1.5%]. The practicality of sampling of data by IAV with Munsell chart, and the reliability of data fit by results of residual error less than 5%, make that this relationship may be used for academic and corporative in carbon stocks estimation for use in forest and environmental management. The EC variation between the studied physiognomies is mainly by distinct density of tree individuals per hectare. The variation of IAV in studied areas is due to the accumulated organic matter on the soil surface, the mineral content and drainage capacity, according to inferences of literature, and this reflecting the different colors of soil in the studied phytophysiognomies.

Otacilio Antunes Santana

2013-12-01

62

Optical instruments for measuring leaf area index in low vegetation: application in arctic ecosystems  

OpenAIRE

Leaf area index (LAI) is a powerful diagnostic of plant productivity. Despite the fact that many methods have been developed to quantify LAI, both directly and indirectly, leaf area index remains difficult to quantify accurately, owing to large spatial and temporal variability. The gap-fraction technique is widely used to estimate the LAI indirectly. However, for low-stature vegetation, the gap-fraction sensor either cannot get totally underneath the plant canopy, thereby missing part of the ...

Wijk, M. T.; Williams, M.

2005-01-01

63

Monitoring responses of Mason Pine to acid rain in China based on remote sensing vegetation index  

Science.gov (United States)

Since the 1970s, acid rain has remained in the public spotlight in both Europe and the United States and recently has emerged as an important problem in other regions such as Southeast Asia. To reveal responses of Masson Pine to acid rain during a long time series in central China, we used the interpolation dataset of acid rain and the Global Inventory Modeling and Mapping Studies (GIMMS) normalized difference vegetation index (NDVI) data to derive the monthly pH and NDVI trajectories based on acidity gradients from 1992 to 2006. Then we analyzed inter-annual and seasonal variation of vegetation growth by improved sinusoidal fitting and regression analysis. In the environment of strong acidity and moderate acidity, the growth of Masson Pine was inhibited during the study period, while the slight acidity promoted growth of Masson Pine to some extent. For the multi-year monthly changing trend of NDVI, late spring to mid autumn, the NDVI showed a decreasing trend, especially in June, while from late autumn to the following spring, the NDVI showed a rising tendency, specifically in December and March.

Jin, Jiaxin; Jiang, Hong; Hou, Chunliang; Zhang, Xiuying; Wang, Ying

2014-03-01

64

Nutritional yield: a proposed index for fresh food improvement illustrated with leafy vegetable data.  

Science.gov (United States)

Consumer interest in food products, including fresh vegetables, with health promoting properties is rising. In fresh vegetables, these properties include vitamins, minerals, dietary fiber, and secondary compounds, which collectively impart a large portion of the dietary, nutritional or health value associated with vegetable intake. Many, including farmers, aim to increase the health-promoting properties of fresh vegetables on the whole but they face at least three obstacles. First, describing crop composition in terms of its nutrition-based impact on human health is complex and there are few, if any, accepted processes and associated metrics for assessing and managing vegetable composition on-farm, at the origin of supply. Second, data suggest that primary and secondary metabolism can be 'in conflict' when establishing the abundance versus composition of a crop. Third, fresh vegetable farmers are rarely compensated for the phytochemical composition of their product. The development and implementation of a fresh vegetable 'nutritional yield' index could be instrumental in overcoming these obstacles. Nutritional yield is a function of crop biomass and tissue levels of health-related metabolites, including bioavailable antioxidant potential. Data from a multi-factor study of leaf lettuce primary and secondary metabolism and the literature suggest that antioxidant yield is sensitive to genetic and environmental production factors, and that changes in crop production and valuation will be required for fresh vegetable production systems to become more focused and purposeful instruments of public health. PMID:22922881

Bumgarner, Natalie R; Scheerens, Joseph C; Kleinhenz, Matthew D

2012-09-01

65

A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study  

International Nuclear Information System (INIS)

Two very different types of approaches are currently in use today for indicating risk of ozone damage to vegetation in Europe. One approach is the so-called AOTX (accumulated exposure over threshold of X ppb) index, which is based upon ozone concentrations only. The second type of approach entails an estimate of the amount of ozone entering via the stomates of vegetation, the AFstY approach (accumulated stomatal flux over threshold of Y nmol m-2 s-1). The EMEP chemical transport model is used to map these different indicators of ozone damage across Europe, for two illustrative vegetation types, wheat and beech forests. The results show that exceedences of critical levels for either type of indicator are widespread, but that the indicators give very different spatial patterns across Europe. Model simulations for year 2020 scenarios suggest reductions in risks of vegetation damage whichever indicator is used, but suggest that AOT40 is much more sensitive to emission control than AFstY values. - Model calculations of AOT40 and AFstY show very different spatial variations in the risks of ozone damage to vegetation

66

A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study  

Energy Technology Data Exchange (ETDEWEB)

Two very different types of approaches are currently in use today for indicating risk of ozone damage to vegetation in Europe. One approach is the so-called AOTX (accumulated exposure over threshold of X ppb) index, which is based upon ozone concentrations only. The second type of approach entails an estimate of the amount of ozone entering via the stomates of vegetation, the AFstY approach (accumulated stomatal flux over threshold of Y nmol m{sup -2} s{sup -1}). The EMEP chemical transport model is used to map these different indicators of ozone damage across Europe, for two illustrative vegetation types, wheat and beech forests. The results show that exceedences of critical levels for either type of indicator are widespread, but that the indicators give very different spatial patterns across Europe. Model simulations for year 2020 scenarios suggest reductions in risks of vegetation damage whichever indicator is used, but suggest that AOT40 is much more sensitive to emission control than AFstY values. - Model calculations of AOT40 and AFstY show very different spatial variations in the risks of ozone damage to vegetation.

Simpson, D. [Norwegian Meteorological Institute, Oslo (Norway)]. E-mail: david.simpson@met.no; Ashmore, M.R. [Stockholm Environment Institute, University of York, York (United Kingdom); Emberson, L. [Stockholm Environment Institute, University of York, York (United Kingdom); Tuovinen, J.-P. [Finnish Meteorological Institute, Helsinki (Finland)

2007-04-15

67

Generating Vegetation Leaf Area Index Earth System Data Record from Multiple Sensors. Part 2; Implementation, Analysis and Validation  

Science.gov (United States)

The evaluation of a new global monthly leaf area index (LAI) data set for the period July 1981 to December 2006 derived from AVHRR Normalized Difference Vegetation Index (NDVI) data is described. The physically based algorithm is detailed in the first of the two part series. Here, the implementation, production and evaluation of the data set are described. The data set is evaluated both by direct comparisons to ground data and indirectly through inter-comparisons with similar data sets. This indirect validation showed satisfactory agreement with existing LAI products, importantly MODIS, at a range of spatial scales, and significant correlations with key climate variables in areas where temperature and precipitation limit plant growth. The data set successfully reproduced well-documented spatio-temporal trends and inter-annual variations in vegetation activity in the northern latitudes and semi-arid tropics. Comparison with plot scale field measurements over homogeneous vegetation patches indicated a 7% underestimation when all major vegetation types are taken into account. The error in mean values obtained from distributions of AVHRR LAI and high-resolution field LAI maps for different biomes is within 0.5 LAI for six out of the ten selected sites. These validation exercises though limited by the amount of field data, and thus less than comprehensive, indicated satisfactory agreement between the LAI product and field measurements. Overall, the intercomparison with short-term LAI data sets, evaluation of long term trends with known variations in climate variables, and validation with field measurements together build confidence in the utility of this new 26 year LAI record for long term vegetation monitoring and modeling studies.

Ganguly, Sangram; Samanta, Arindam; Schull, Mitchell A.; Shabanov, Nikolay V.; Milesi, Cristina; Nemani, Ramajrushna R,; Knyazikhin, Yuri; Myneni, Ranga B.

2008-01-01

68

Estimating soil moisture and the relationship with crop yield using surface temperature and vegetation index  

Science.gov (United States)

Soil moisture availability affects rainfed crop yield. Therefore, the development of methods for pre-harvest yield prediction is essential for the food security. A study was carried out to estimate regional crop yield using the Temperature Vegetation Dryness Index (TVDI). Triangular scatters from land surface temperature (LST) and enhanced vegetation index (EVI) space from MODIS (Moderate Resolution Imaging Spectroradiometer) were utilized to obtain TVDI and to estimate soil moisture availability. Then soybean and wheat crops yield was estimated on four agro-climatic zones of Argentine Pampas. TVDI showed a strong correlation with soil moisture measurements, with R2 values ranged from 0.61 to 0.83 and also it was in agreement with spatial pattern of soil moisture. Moreover, results showed that TVDI data can be used effectively to predict crop yield on the Argentine Pampas. Depending on the agro-climatic zone, R2 values ranged from 0.68 to 0.79 for soybean crop and 0.76 to 0.81 for wheat. The RMSE values were 366 and 380 kg ha-1 for soybean and they varied between 300 and 550 kg ha-1 in the case of wheat crop. When expressed as percentages of actual yield, the RMSE values ranged from 12% to 13% for soybean and 14% to 22% for wheat. The bias values indicated that the obtained models underestimated soybean and wheat yield. Accurate crop grain yield forecast using the developed regression models was achieved one to three months before harvest. In many cases the results were better than others obtained using only a vegetation index, showing the aptitude of surface temperature and vegetation index combination to reflect the crop water condition. Finally, the analysis of a wide range of soil moisture availability allowed us to develop a generalized model of crop yield and dryness index relationship which could be applicable in other regions and crops at regional scale.

Holzman, M. E.; Rivas, R.; Piccolo, M. C.

2014-05-01

69

Net Radiation and Vegetation NDVI  

Science.gov (United States)

This site allows you to combine the NDVI vegetation index with Net Solar Radiation values. The Normalized Difference Vegetation Index, or NDVI, is an index of green leaf density. The higher the value, the more luxuriant the vegetation. This is but one of many animated datasets that can be combined to introduce correlations and interactions between radiant energy and the biosphere.

NASA Earth Observatory

70

Predicting maize yield in Zimbabwe using dry dekads derived from remotely sensed Vegetation Condition Index  

Science.gov (United States)

Maize is a key crop contributing to food security in Southern Africa yet accurate estimates of maize yield prior to harvesting are scarce. Timely and accurate estimates of maize production are essential for ensuring food security by enabling actionable mitigation strategies and policies for prevention of food shortages. In this study, we regressed the number of dry dekads derived from VCI against official ground-based maize yield estimates to generate simple linear regression models for predicting maize yield throughout Zimbabwe over four seasons (2009-10, 2010-11, 2011-12, and 2012-13). The VCI was computed using Normalized Difference Vegetation Index (NDVI) time series dataset from the SPOT VEGETATION sensor for the period 1998-2013. A significant negative linear relationship between number of dry dekads and maize yield was observed in each season. The variation in yield explained by the models ranged from 75% to 90%. The models were evaluated with official ground-based yield data that was not used to generate the models. There is a close match between the predicted yield and the official yield statistics with an error of 33%. The observed consistency in the negative relationship between number of dry dekads and ground-based estimates of maize yield as well as the high explanatory power of the regression models suggest that VCI-derived dry dekads could be used to predict maize yield before the end of the season thereby making it possible to plan strategies for dealing with food deficits or surpluses on time.

Kuri, Farai; Murwira, Amon; Murwira, Karin S.; Masocha, Mhosisi

2014-12-01

71

Global trends in vegetation phenology from 32-year GEOV1 leaf area index time series  

Science.gov (United States)

Phenology is a critical component in understanding ecosystem response to climate variability. Long term data records from global mapping satellite platforms are valuable tools for monitoring vegetation responses to climate change at the global scale. Phenology satellite products and trend detection from satellite time series are expected to contribute to improve our understanding of climate forcing on vegetation dynamics. The capacity of monitoring ecosystem responses to global climate change was evaluated in this study from the 32-year time series of global Leaf Area Index (LAI) which have been recently produced within the geoland2 project. The long term GEOV1 LAI products were derived from NOAA/AVHRR (1981 to 2000) and SPOT/VGT (1999 to the present) with specific emphasis on consistency and continuity. Since mid-November, GEOV1 LAI products are freely available to the scientific community at geoland2 portal (www.geoland2.eu/core-mapping-services/biopar.html). These products are distributed at a dekadal time step for the period 1981-2000 and 2000-2012 at 0.05° and 1/112°, respectively. The use of GEOV1 data covering a long time period and providing information at dense time steps are expected to increase the reliability of trend detection. In this study, GEOV1 LAI time series aggregated at 0.5° spatial resolution are used. The CACAO (Consistent Adjustment of the Climatology to Actual Observations) method (Verger et al, 2013) was applied to characterize seasonal anomalies as well as identify trends. For a given pixel, CACAO computes, for each season, the time shift and the amplitude difference between the current temporal profile and the climatology computed over the 32 years. These CACAO parameters allow quantifying shifts in the timing of seasonal phenology and inter-annual variations in magnitude as compared to the average climatology. Interannual variations in the timing of the Start of Season and End of Season, Season Length and LAI level in the peak of the growing season are analyzed. Trend analysis with robust statistical test of significance is conducted. Climate variables (precipitation, temperature, radiation) are then used to interpret the anomaly patterns detected in vegetation response.

Verger, Aleixandre; Baret, Frédéric; Weiss, Marie; Filella, Iolanda; Peñuelas, Josep

2013-04-01

72

Assessing Land Degradation and Desertification Using Vegetation Index Data: Current Frameworks and Future Directions  

OpenAIRE

Land degradation and desertification has been ranked as a major environmental and social issue for the coming decades. Thus, the observation and early detection of degradation is a primary objective for a number of scientific and policy organisations, with remote sensing methods being a candidate choice for the development of monitoring systems. This paper reviews the statistical and ecological frameworks of assessing land degradation and desertification using vegetation index data. The devel...

Higginbottom, Thomas P.; Elias Symeonakis

2014-01-01

73

[Kriging analysis of vegetation index depression in peak cluster karst area].  

Science.gov (United States)

In order to master the spatial variability of the normal different vegetation index (NDVI) of the peak cluster karst area, taking into account the problem of the mountain shadow "missing" information of remote sensing images existing in the karst area, NDVI of the non-shaded area were extracted in Guohua Ecological Experimental Area, in Pingguo County, Guangxi applying image processing software, ENVI. The spatial variability of NDVI was analyzed applying geostatistical method, and the NDVI of the mountain shadow areas was predicted and validated. The results indicated that the NDVI of the study area showed strong spatial variability and spatial autocorrelation resulting from the impact of intrinsic factors, and the range was 300 m. The spatial distribution maps of the NDVI interpolated by Kriging interpolation method showed that the mean of NDVI was 0.196, apparently strip and block. The higher NDVI values distributed in the area where the slope was greater than 25 degrees of the peak cluster area, while the lower values distributed in the area such as foot of the peak cluster and depression, where slope was less than 25 degrees. Kriging method validation results show that interpolation has a very high prediction accuracy and could predict the NDVI of the shadow area, which provides a new idea and method for monitoring and evaluation of the karst rocky desertification. PMID:22720596

Yang, Qi-Yong; Jiang, Zhong-Cheng; Ma, Zu-Lu; Cao, Jian-Hua; Luo, Wei-Qun; Li, Wen-Jun; Duan, Xiao-Fang

2012-04-01

74

On the relationship between some production parameters and a vegetation index in viticulture  

Science.gov (United States)

The use and timing of many agronomical practices such as the scheduling of irrigation and harvesting are dependent on accurate vineyard sampling of qualitative and productive parameters. Crop forecasting also depends on the representativeness of vineyard samples during the whole phenological period. This manuscript summarizes the last two years of precision viticulture in Sicily (Italy); agronomic campaigns were carried out in 2012 and 2013 within the "Tenute Rapitalà" and "Donnafugata" farms. Normalized Difference Vegetation Index derived from satellite images (RapidEye) acquired at berry set, pre-veraison and ripening phenological stages (occurred at June, July and August respectively) have been related to production parameters (sugar and anthocyanins contents) at harvesting of a selected red autochthonous cultivar (Nero D'Avola). The research aims to assess how robust are prediction models based on simple linear regression analysis, in particular: 1) whether there is a suitable period for acquiring the remote sensing image to evaluate these parameters at harvesting, when their knowledge is required; 2) if these relationships are consistent between years or need to be re-calibrated; 3) the models transferability to other vineyard of the same cultivar.

Santangelo, Tanino; Di Lorenzo, R.; La Loggia, G.; Maltese, A.

2013-10-01

75

Competition for water between beech seedlings and surrounding vegetation in different light and vegetation composition conditions  

OpenAIRE

- To gain a better understanding of beech growth requirements and assess the competition with the surrounding vegetation at two successional stages after agricultural land abandonment, we introduced two-year-old beech seedlings (i) in a recently abandoned meadow (one half weeded) and (ii) in an old meadow colonised by 25-year-old natural Scots pine, with one part thinned to increase light availability at ground level. Beech seedlings presented significantly different stem diameter growth rate...

Coll, Lluis; Balandier, Philippe; Picon-cochard, Catherine; Pre?vosto, Bernard; Curt, Thomas

2003-01-01

76

Methane emissions in Danish riparian wetlands : Ecosystem comparison and pursuit of vegetation indexes as predictive tools  

DEFF Research Database (Denmark)

The present study was conducted to (i) investigate parameters influencing the fluxes of the greenhouse gas methane (CH4) in Danish riparian wetlands with contrasting vegetation characteristics and (ii) develop models relating CH4 emissions to soil and/or vegetation parameters integrating the spatial and temporal variability in the fluxes. Fluxes of CH4 were monitored in 12 wetland plots over a year using static chambers, yielding a dataset with more than 800 measured fluxes of CH4. Yearly emissions of CH4 ranged from ?0.2 to 38.3 g CH4-C m?2 year?1, and significant effects of groundwater level, soil temperature (10 cm depth), peat depth, sulfate, nitrate, and soil carbon content were found. Two methods based on easily available environmental parameters to estimate yearly CH4 emissions from riparian wetlands are presented. The first uses a generalized linear model (GLM) to predict yearly CH4 emissions based on the humidity preference of vegetation (Ellenberg-F), peat depth and degree of humification of the peat (von Post index). The second method relies solely on plant species composition and uses weighted-average regression and calibration to link the vegetation assemblage to yearly CH4 emission. Both models gave reliable predictions of the yearly CH4 fluxes in riparian wetlands (modeling efficiency > 0.35). Our findings support the use of vegetation, possibly in combination with some soil parameters such as peat depth, as indicator of CH4 emission in wetlands.

Audet, Joachim; Johansen, Jan Ravn

2013-01-01

77

Assessment of RapidEye vegetation indices for estimation of leaf area index and biomass in corn and soybean crops  

Science.gov (United States)

Leaf area index (LAI) and biomass are important indicators of crop development and the availability of this information during the growing season can support farmer decision making processes. This study demonstrates the applicability of RapidEye multi-spectral data for estimation of LAI and biomass of two crop types (corn and soybean) with different canopy structure, leaf structure and photosynthetic pathways. The advantages of Rapid Eye in terms of increased temporal resolution (?daily), high spatial resolution (?5 m) and enhanced spectral information (includes red-edge band) are explored as an individual sensor and as part of a multi-sensor constellation. Seven vegetation indices based on combinations of reflectance in green, red, red-edge and near infrared bands were derived from RapidEye imagery between 2011 and 2013. LAI and biomass data were collected during the same period for calibration and validation of the relationships between vegetation indices and LAI and dry above-ground biomass. Most indices showed sensitivity to LAI from emergence to 8 m2/m2. The normalized difference vegetation index (NDVI), the red-edge NDVI and the green NDVI were insensitive to crop type and had coefficients of variations (CV) ranging between 19 and 27%; and coefficients of determination ranging between 86 and 88%. The NDVI performed best for the estimation of dry leaf biomass (CV = 27% and r2 = 090) and was also insensitive to crop type. The red-edge indices did not show any significant improvement in LAI and biomass estimation over traditional multispectral indices. Cumulative vegetation indices showed strong performance for estimation of total dry above-ground biomass, especially for corn (CV ? 20%). This study demonstrated that continuous crop LAI monitoring over time and space at the field level can be achieved using a combination of RapidEye, Landsat and SPOT data and sensor-dependant best-fit functions. This approach eliminates/reduces the need for reflectance resampling, VIs inter-calibration and spatial resampling.

Kross, Angela; McNairn, Heather; Lapen, David; Sunohara, Mark; Champagne, Catherine

2015-02-01

78

A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study.  

Science.gov (United States)

Two very different types of approaches are currently in use today for indicating risk of ozone damage to vegetation in Europe. One approach is the so-called AOTX (accumulated exposure over threshold of Xppb) index, which is based upon ozone concentrations only. The second type of approach entails an estimate of the amount of ozone entering via the stomates of vegetation, the AFstY approach (accumulated stomatal flux over threshold of Y nmol m(-2) s(-1)). The EMEP chemical transport model is used to map these different indicators of ozone damage across Europe, for two illustrative vegetation types, wheat and beech forests. The results show that exceedences of critical levels for either type of indicator are widespread, but that the indicators give very different spatial patterns across Europe. Model simulations for year 2020 scenarios suggest reductions in risks of vegetation damage whichever indicator is used, but suggest that AOT40 is much more sensitive to emission control than AFstY values. PMID:16762467

Simpson, D; Ashmore, M R; Emberson, L; Tuovinen, J-P

2007-04-01

79

The relationship between vegetation supply water index and forest resource of Bogd Khaan Mountain in the Mongolia  

Science.gov (United States)

Bogd Khan Mountain all areas consist of 41129 hectares from 22992 hectares 55.9 of the forest about 20 rivers originate from mountain. Therefore Tuul river recourse depends on the flow of these water resources. In this research paper for using Landsat-5 satellite estimation of forest resource of Bogd Khan Mountain. How depending of Tuul river watering resource. This area estimation of vegetation index soil, soil temperature, soil water supply is the index to how depends on each other. Result is relate of vegetation index and water supply index directly but soil temperature undirectly reciprocal value. There for forest area, soil to low and it's possible to accumulate moisture.

Naranmandah, Z.; Tuya, S.; Batbayar, J.

2014-11-01

80

Lipid Peroxidation in Rat Liver using Different Vegetable Oils  

International Nuclear Information System (INIS)

The objective of the study was to evaluate the effect of different vegetable oils (Red Palm Olien (RPO), Palm Olein (PO), Corn Oil (CO) and Coconut Oil on lipid peroxidation of rat liver. One hundred and thirty two Sprague Dawley male rats were randomly divided into two groups. The first group contains seventy two rats were divided into twelve groups of 6 rats per group and were treated with different concentrations of RPO (5 %, 10 % and 15 %) for 2, 4 and 8 weeks. The second group contains sixty male rats were randomly divided into ten groups of 6 rats per group and were treated with 15 % of RPO, PO, CO and COC for 4 and 8 weeks. The results shows that after 8 weeks of treatment the malonaldehyde (MDA) value in RPO group was significantly lower (P?0.05) than control or vegetable oils studied. These experiments suggested that red palm olein antioxidants present in rat diets may better attenuate peroxyl radical than other vegetable oil studied. (author)

81

[Vegetation index estimation by chlorophyll content of grassland based on spectral analysis].  

Science.gov (United States)

Comparing the methods of existing remote sensing research on the estimation of chlorophyll content, the present paper confirms that the vegetation index is one of the most practical and popular research methods. In recent years, the increasingly serious problem of grassland degradation. This paper, firstly, analyzes the measured reflectance spectral curve and its first derivative curve in the grasslands of Songpan, Sichuan and Gongger, Inner Mongolia, conducts correlation analysis between these two spectral curves and chlorophyll content, and finds out the regulation between REP (red edge position) and grassland chlorophyll content, that is, the higher the chlorophyll content is, the higher the REIP (red-edge inflection point) value would be. Then, this paper constructs GCI (grassland chlorophyll index) and selects the most suitable band for retrieval. Finally, this paper calculates the GCI by the use of satellite hyperspectral image, conducts the verification and accuracy analysis of the calculation results compared with chlorophyll content data collected from field of twice experiments. The result shows that for grassland chlorophyll content, GCI has stronger sensitivity than other indices of chlorophyll, and has higher estimation accuracy. GCI is the first proposed to estimate the grassland chlorophyll content, and has wide application potential for the remote sensing retrieval of grassland chlorophyll content. In addition, the grassland chlorophyll content estimation method based on remote sensing retrieval in this paper provides new research ideas for other vegetation biochemical parameters' estimation, vegetation growth status' evaluation and grassland ecological environment change's monitoring. PMID:25752061

Xiao, Han; Chen, Xiu-Wan; Yang, Zhen-Yu; Li, Huai-Yu; Zhu, Han

2014-11-01

82

Long-term vegetation monitoring for different habitats in floodplains  

Directory of Open Access Journals (Sweden)

Full Text Available A floodplain-restoration project along the Danube between Neuburg and Ingolstadt (Germany aims to bring back water and sediment dynamic to the floodplain. The accompanied long-term monitoring has to document the changes in biodiversity related to this new dynamics. Considerations on and results of the vegetation monitoring concept are documented in this paper. In a habitat rich ecosystem like a floodplain different habitats (alluvial forest, semi-aquatic/aquatic sites have different demands on the sampling methods. Therefore, different monitoring designs (preferential, random, systematic, stratified random and transect sampling are discussed and tested for their use in different habitat types of the floodplain. A stratified random sampling is chosen for the alluvial forest stands, as it guarantees an equal distribution of the monitoring plots along the main driving factors, i.e. influence of water. The parameters distance to barrage, ecological flooding, height above thalweg and distance to the new floodplain river are used for stratifying and the plots are placed randomly into these strata, resulting in 117 permanent plots. Due to small changes at the semi-aquatic/aquatic sites a transect sampling was chosen. Further, a rough stratification (channel bed, river bank adjacent floodplain was implemented, which was only possible after the start of the restoration project. To capture the small-scale changes due to the restoration measures on the vegetation, 99 additional plots completed the transect sampling. We conclude that hetereogenous study areas need different monitoring approaches, but, later on, a joint analysis must be possible

LANG Petra

2013-12-01

83

Estimation of vegetation parameters such as Leaf Area Index from polarimetric SAR data  

Science.gov (United States)

This work presents the analysis of the capability to use the radar backscatter coefficient in semi-arid zones to estimate the vegetation crown in terms of Leaf Area Index (LAI). The research area is characterized by the presence of a pine forest with shrubs as an underlying vegetation layer (understory), olive trees, natural grove areas and eucalyptus trees. The research area was imaged by an airborne RADAR system in L-band during February 2009. The imagery includes multi-look radar images. All the images were fully polarized i.e., HH, VV, HV polarizations. For this research we used the central azimuth angle (113° ). We measured LAI using the ?T Sun Scan Canopy Analysis System. Verification was done by analytic calculations and digital methods for the leaf's and needle's surface area. In addition, we estimated the radar extinction coefficient of the vegetation volume by comparing point calibration targets (trihedral corner reflectors with 150cm side length) within and without the canopy. The radar extinction in co- polarized images was ~26dB and ~24dB for pines and olives respectively, compared to the same calibration target outside the vegetation. We used smaller trihedral corner reflectors (41cm side length) and covered them with vegetation to measure the correlation between vegetation density, LAI and radar backscatter coefficient for pines and olives under known conditions. An inverse correlation between the radar backscatter coefficient of the trihedral corner reflectors covered by olive branches and the LAI of those branches was observed. The correlation between LAI and the optical transmittance was derived using the Beer-Lambert law. In addition, comparing this law's principle to the principle of the radar backscatter coefficient production, we derived the equation that connects between the radar backscatter coefficient and LAI. After extracting the radar backscatter coefficient of forested areas, all the vegetation parameters were used as inputs for the MIMICS model that simulates the radar backscatter coefficient of pines. The model results show a backscatter of -18dB in HV polarization which is 13dB higher than the mean pines backscatter in the radar images, whereas the co-polarized images revealed a backscatter of -10dB which is 23dB higher than the actual backscatter value deriver from the radar images. Therefore, next step in the research will incorporate other vegetation parameters and attempt to understand the discrepancies between the simulation and the actual data.

Hetz, Marina; Blumberg, Dan G.; Rotman, Stanley R.

2010-05-01

84

Variação do Índice de Vegetação por Diferença Normalizada na lagoa Itapeva, litoral norte do Rio Grande do Sul, Brasil, a partir de análise de séries temporais / Variations of the Normalized Difference Vegetation Index (NDVI) in the Itapeva-RS lake, north coast of Rio Grande do Sul, Brazil, from temporal series analysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo do trabalho foi analisar os padrões de comportamento espaço-temporal dos valores do Índice de Vegetação por Diferença Normalizada (NDVI) na lagoa Itapeva-RS, por meio de imagens Landsat TM5 e ETM+7, compreendendo o período de 1985 a 2010. Para a análise do comportamento espaço-temporal fo [...] ram utilizadas classes de Índice de Vegetação por Diferença Normalizada (NDVI) e Análise por Séries Temporais (TSA) de imagens. Para validação dos padrões observados foram coletadas amostras de água em seis pontos na lagoa Itapeva para clorofila_a, Totais de Sólidos Suspensos e transparência do disco Secchi. Estes resultados foram correlacionados com os valores de NDVI. Os mapas de classes de NDVI gerados após a análise da TSA evidenciaram padrões de dinâmica espaciais e sazonais associados as variáveis ambientais atuantes, permitindo o estabelecimento de três grandes compartimentos para a lagoa Itapeva: norte, centro e sul. A análise da série temporal de imagens mostra que o aumento e o decréscimo dos valores de NDVI estão associados aos períodos de floração do fitoplâncton. Concluiu-se que a análise da Série Temporal de imagens Landsat foi satisfatória no que se refere ao comportamento espaço-temporal da variação das classes de NDVI. Abstract in english The objective of this study was to analyze the pattern spatial-temporal values of the Normalized Difference Vegetation Index (NDVI) in Itapeva-RS lake, using Landsat TM5 and ETM + 7 images, from 1985 through 2010. For the analysis of space-temporal behavior classes was used Normalized Difference Veg [...] etation Index (NDVI) classes and Temporal Series Analysis (TSA). To validate the observed patterns were collected water samples from six points in the Itapeva Lake for clorofila_a, Total suspended solids and Secchi disk transparency. These results were correlated with NDVI values. The NDVI classes maps generated after analysis of TSA, showed dynamic patterns of seasonal and spatial associated with environmental variables that were actuating, allowing the establishment of three distinctive surfaces in Itapeva Lake: north, center and south. The Temporal Series Analysis of images shows that the increase and decrease of NDVI values are associated with periods of phytoplankton bloom. One concluded that the Temporal Series Analysis of Landsat images was satisfactory with regard to the behavior of spatial and temporal variation of NDVI classes.

Juliane Beatriz, Lissner; Laurindo Antonio, Guasselli.

2013-08-01

85

Differences in the deposition of radionuclides to leafy vegetables  

International Nuclear Information System (INIS)

To quantify the variability in deposition to several species, the dry deposition of gaseous elemental radio-iodine and particulate radio-caesium on mature leafy vegetables was studied inside a deposition chamber by comparative experiments. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce, curly kale, white cabbage and spinach was performed under homogeneous and controlled conditions (131 vertical stroke 2-portion, particle median, stomata opening, air humidity and temperature). Significant differences were observed for the 131 vertical stroke deposition on spring vegetables: the deposition on spinach was roughly 3times that on leaf lettuce, 4times that on endive and 9times that on head lettuce. For 134Cs, there was no significant difference between spinach and leaf lettuce, about twice the amount was deposited on both species as on endive and 3times as on head lettuce. All summer vegetables showed differences in deposition. For Iodine, the deposition on spinach was roughly 3times (6times) that on curly kale and 35times (100times) that on white cabbage in the 2 experiments. For Caesium, the deposition to curly kale was highest, about twice that on spinach and 35times (80times) that on white cabbage. The deposition was always the lowest on the closed heads of white cabbage and head lettuce. The many open stomata of spinach increased the efficiency of gaseous deposition. In addition, rough and crimpy leafs increased the particle deposition efficiency. The estimation of the deposition velocity showed that dry deposition was in average about 8times higher for 131 vertical stroke than for 134Cs. The influence of the particle size on the deposition velocity was small in the considered size range. Washing could reduce the contamination by about 10% for 131 vertical stroke and 45% for 134Cs. (orig.)

86

Chemical changes in bromeliad leaves at different vegetative stages  

International Nuclear Information System (INIS)

Studies concerning the accumulating capacity of native epiphytic bromeliads are of utmost relevance, due to the continuous incorporation of chemical elements provided by these organisms in the ecosystems. Bromeliad species from diverse Sao Paulo State conservation units, Brazil, were sampled for young, mature and old leaves using a sustainable sampling method. By applying INAA, the accumulation of ten chemical elements, i.e. Br, Ca, Co, Fe, K, Na, Rb, Sc, Sr and Zn, was investigated in different leaf vegetative stages. The bromeliads showed divergent chemical element distribution patterns, demonstrating a real complexity in the accumulation and translocation mechanisms utilized by these plants. (author)

87

Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring  

Directory of Open Access Journals (Sweden)

Full Text Available Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs, from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER (15 m and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS (250 m – 500 m sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors’ products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house” surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results associated with the ASTER algorithm, including additional quality assessments of the ASTER and MODIS products with other atmospheric radiative transfer codes.

Hirokazu Yamamoto

2008-04-01

88

Agricultural Drought Pattern in West Java Using Thermal Vegetation Index from Modis-Terra Satellite  

Directory of Open Access Journals (Sweden)

Full Text Available This study examines agricultural drought paddy fields in West Java. The aims of this research are to know the pattern and distribution of paddy field drought in West Java and the correlation between drought and the physical characteristics. The agricultural drought is obtained from TVI (Thermal Vegetation Index model. TVI is derived from MODIS Terra satellite image, which is the ratio between the LST (Land Surface Temperature and EVI (Enhanced Vegetation Index. Physical factors studied are rainfall, l slope, geomorphology, soil drainage, and irrigation areas. The most severe drought occurred in September 2006 because of El Nino, covering 806,564 ha, and distributed in almost all West Java Province while the lowest occurred in September 2010 because of La Nina, covering 101,959 ha, and mostly distributed in Subang and Indramayu district. Spatial distribution of drought in 2000-2011 has the same pattern. At the start of the dry season (May drought occurred in the north (along the coast then expanded to the east / south in the middle of the dry season (July-August and then increased further to the west at the end of the dry season (September. Incidence of drought has correlation with the physical condition of the area, but the most influential is the rainfall based on Chi-square test.

Sri Hardiyanti Purwadhi

2013-04-01

89

Assessing Land Degradation and Desertification Using Vegetation Index Data: Current Frameworks and Future Directions  

Directory of Open Access Journals (Sweden)

Full Text Available Land degradation and desertification has been ranked as a major environmental and social issue for the coming decades. Thus, the observation and early detection of degradation is a primary objective for a number of scientific and policy organisations, with remote sensing methods being a candidate choice for the development of monitoring systems. This paper reviews the statistical and ecological frameworks of assessing land degradation and desertification using vegetation index data. The development of multi-temporal analysis as a desertification assessment technique is reviewed, with a focus on how current practice has been shaped by controversy and dispute within the literature. The statistical techniques commonly employed are examined from both a statistical as well as ecological point of view, and recommendations are made for future research directions. The scientific requirements for degradation and desertification monitoring systems identified here are: (I the validation of methodologies in a robust and comparable manner; and (II the detection of degradation at minor intensities and magnitudes. It is also established that the multi-temporal analysis of vegetation index data can provide a sophisticated measure of ecosystem health and variation, and that, over the last 30 years, considerable progress has been made in the respective research.

Thomas P. Higginbottom

2014-10-01

90

Use of Radar Vegetation Index (RVI) in Passive Microwave Algorithms for Soil Moisture Estimates  

Science.gov (United States)

The Soil Moisture Active Passive (SMAP) satellite will provide a unique opportunity for the estimation of soil moisture by having simultaneous radar and radiometer measurements available. As with the Soil Moisture and Ocean Salinity (SMOS) satellite, the soil moisture algorithms will need to account for the contribution of vegetation to the brightness temperature. Global maps of vegetation volumetric water content (VWC) are difficult to obtain, and the SMOS mission has opted to estimate the optical depth of standing vegetation by using a relationship between the VWC and the leaf area index (LAI). LAI is estimated from optical remote sensing or through soil-vegetation-atmosphere transfer modeling. During the growing season, the VWC of agricultural crops can increase rapidly, and if cloud cover exists during an optical acquisition, the estimation of LAI may be delayed, resulting in an underestimation of the VWC and overestimation of the soil moisture. Alternatively, the radar vegetation index (RVI) has shown strong correlation and linear relationship with VWC for rice and soybeans. Using the SMAP radar to produce RVI values that are coincident to brightness temperature measurements may eliminate the need for LAI estimates. The SMAP Validation Experiment 2012 (SMAPVEX12) was a cal/val campaign for the SMAP mission held in Manitoba, Canada, during a 6-week period in June and July, 2012. During this campaign, soil moisture measurements were obtained for 55 fields with varying soil texture and vegetation cover. Vegetation was sampled from each field weekly to determine the VWC. Soil moisture measurements were taken coincident to overpasses by an aircraft carrying the Passive and Active L-band System (PALS) instrumentation. The aircraft flew flight lines at both high and low altitudes. The low altitude flight lines provided a footprint size approximately equivalent to the size of the SMAPVEX12 field sites. Of the 55 field sites, the low altitude flight lines provided measurements for 15 fields. One field was planted in corn; three were pasture; six were soybeans; three were wheat; and two were winter wheat. The average RVI for each field was determined for each PALS overpass, with sampled radar data confined to the field dimensions. A linear interpolation was conducted between measured values of VWC to estimate a daily VWC value. A linear regression was conducted between the average VWC and the RVI, for each vegetation type. A positive linear relationship was found for all crops, with the exception of pasture. The correlation between the RVI and VWC was strong for corn and pasture, but moderate for soybeans and winter wheat; however, the correlation for corn was not significant. The developed models were utilized to provide a calculated VWC which was inputted into a modified version of the Land Parameter Retrieval Model (LPRM) to determine the error associated with using a calculated VWC from the RVI versus measured VWC data. The LPRM outputs for both scenarios were compared to the PALS radiometer measurements of brightness temperature.

Rowlandson, T. L.; Berg, A. A.

2013-12-01

91

Camera derived vegetation greenness index as proxy for gross primary production in a low Arctic wetland area  

DEFF Research Database (Denmark)

The Arctic is experiencing disproportionate warming relative to the global average, and the Arctic ecosystems are as a result undergoing considerable changes. Continued monitoring of ecosystem productivity and phenology across temporal and spatial scales is a central part of assessing the magnitude of these changes. This study investigates the ability to use automatic digital camera images (DCIs) as proxy data for gross primary production (GPP) in a complex low Arctic wetland site. Vegetation greenness computed from DCIs was found to correlate significantly (R-2 = 0.62, p <0.001) with a normalized difference vegetation index (NDVI) product derived from the WorldView-2 satellite. An object-based classification based on a bi-temporal image composite was used to classify the study area into heath, copse, fen, and bedrock. Temporal evolution of vegetation greenness was evaluated and modeled with double sigmoid functions for each plant community. GPP at light saturation modeled from eddy covariance (EC) flux measurements were found to correlate significantly with vegetation greenness for all plant communities in the studied year (i.e., 2010), and the highest correlation was found between modeled fen greenness and GPP (R-2 = 0.85, p <0.001). Finally, greenness computed within modeled EC footprints were used to evaluate the influence of individual plant communities on the flux measurements. The study concludes that digital cameras may be used as a cost-effective proxy for potential GPP in remote Arctic regions. (C) 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS) Published by Elsevier B.V. All rights reserved.

Westergaard-Nielsen, Andreas; Lund, Magnus

2013-01-01

92

Determination index of compatible vegetable species with the lines of electric power transmission  

International Nuclear Information System (INIS)

With the purpose of designing methods to clearly identify which plant species generate electrical ground discharges in energy transmission line service corridors and thus avoid the frequent pruning of all Vegetation present in the corridors this study proposes and evaluates compatibility index of plant species with transmission lines, based on six variables: maximum height, growth form, ecological group, life zone, and abundance and frequency of each species. This index was tested in 20 plots of information was collected on all vascular plans present yielding 2147 individuals belonging to 485 species and 105 families, the most discriminating variables in the model were life zone and ecological group, based upon an analysis of principal components. This index applied to the 147 fully identified species with DBH = 2,5 cm showed that Cecropia peltata and Jacaranda copaia were the most problematic species for service lines. Furthermore, a catalogue was developed containing general information and a photographic record of some of the species considered as compatible as a reference for use during maintenance work

93

Chlorophyll content mapping of urban vegetation in the city of Valencia based on the hyperspectral NAOC index  

OpenAIRE

Spatially distributed chlorophyll content of urban vegetation provides an important indicator of a plant's health status, which might depend on the habitat quality of the specific urban environment. Recent advances in optical remote sensing led to improved methodologies to monitor vegetation properties. The hyperspectral index NAOC (Normalized Area Over reflectance Curve) is one of these new tools that can be used for mapping chlorophyll content. In this paper we present the work done to quan...

Delegido, Jes S.; Wittenberghe, Shari; Verrelst, Jochem; Ortiz, Violeta; Veroustraete, Frank; Valcke, Roland; Samson, Roeland; Rivera, Juan P.; Tenjo, Carolina; Moreno, Jos

2014-01-01

94

GREEN AREA AND VEGETATION COVER INDEXES FOR PARRAL CITY (CHILE USING PHOTOINTERPRETATION AND GIS  

Directory of Open Access Journals (Sweden)

Full Text Available The importance of the green areas is increasing since they are an important factor in the health and welfare of urban population. Therefore, in Parral city, in Central Chile, it was quantified and analyzed the availability of green areas and vegetation cover, using aerial photographs scale 1:10000 and Geographic Information Systems (GIS. In a first stage, urban street trees were quantified through a simple random sample of twenty-four units with field measurements combined with measurements on aerial photographs, from which it was obtained the surface provided. Subsequently, through the  creation of GIS layers, the surface of existing green areas and available open spaces were obtained. In addition, through supervised digital classification, the surface covered by urban forestry in private spaces was calculated. Quantity indexes show that Parral city currently has 12.72 ha of green areas, equivalent to 4.82 m2/hab, which implies a green area frequency of 0.022 m2/m2. These values could be improved, if the available open space are incorporated and thereby reach 12.06 m2 per inhabitant. In relation with availability indexes it was established that the average of accessibility to a green area is 327.2 m. Moreover, assuming a buffer of 200 m around the green areas, it was determined that there are 5160 houses with the basic service (56.4%. By incorporating the available open spaces, these values decrease significantly obtaining an average of accessibility to a green area of 213.7 m and coverage of basic service of 79.2%. Finally, it was estimated that the existing vegetation within the urban blocks (urban forest in private spaces represents an important resource 17.8 times larger than urban street trees, so it should be considered within the municipal plans and policies.

Carlos Mena

2011-09-01

95

Identification of croplands of winter cereals in Rio Grande do Sul state, Brazil, through unsupervised classification of normalized difference vegetation index images / Identificação de áreas agrícolas cultivadas com cereais de inverno no Rio Grande do Sul por meio de classificação não supervisionada de imagens de índice de vegetação por diferença normalizada  

Scientific Electronic Library Online (English)

Full Text Available O objetivo deste trabalho foi propor métodos para identificação de áreas agrícolas cultivadas com cereais de inverno na região norte do Rio Grande do Sul. Para isso, foi analisada a evolução do Índice de Vegetação por Diferença Normalizada (NDVI), proveniente de imagens do sensor MODIS, de abril a d [...] ezembro de 2000 a 2008. Foram elaboradas máscaras de cultivo pela subtração de imagens de mínimo NDVI (abril e maio), das de máximo NDVI (junho a outubro). Posteriormente, foi realizada a classificação não supervisionada das imagens (algoritmo Isodata), considerando as áreas pertencentes às máscaras de cultivo. As máscaras de cultivo identificaram pixels com as maiores variações de biomassa verde, associadas ou não à produção de grãos. A classificação não supervisionada gerou classes cujos perfis temporais foram condizentes com corpos d'água, pastagens e cultivos de cereais de inverno para produção de grãos e para cobertura do solo. Os perfis temporais de áreas destinadas à produção de grãos concordaram com os padrões de cultivo dos cereais de inverno na região (ciclo de desenvolvimento, manejo e épocas de semeadura). A classificação não supervisionada de áreas identificadas por máscaras de cultivo permite identificar e monitorar cultivos de cereais de inverno que se assemelham quanto à morfologia e à fenologia. Abstract in english This study aimed to propose methods to identify croplands cultivated with winter cereals in the northern region of Rio Grande do Sul State, Brazil. Thus, temporal profiles of Normalized Difference Vegetation Index (NDVI) from MODIS sensor, from April to December of the 2000 to 2008, were analyzed. F [...] irstly, crop masks were elaborated by subtracting the minimum NDVI image (April to May) from the maximum NDVI image (June to October). Then, an unsupervised classification of NDVI images was carried out (Isodata), considering the crop mask areas. According to the results, crop masks allowed the identification of pixels with greatest green biomass variation. This variation might be associated or not with winter cereals areas established to grain production. The unsupervised classification generated classes in which NDVI temporal profiles were associated with water bodies, pastures, winter cereals for grain production and for soil cover. Temporal NDVI profiles of the class winter cereals for grain production were in agree with crop patterns in the region (developmental stage, management standard and sowing dates). Therefore, unsupervised classification based on crop masks allows distinguishing and monitoring winter cereal crops, which were similar in terms of morphology and phenology.

Amanda H., Junges; Denise C., Fontana; Daniele G., Pinto.

2013-08-01

96

Calibration of a Species-Specific Spectral Vegetation Index for Leaf Area Index (LAI Monitoring: Example with MODIS Reflectance Time-Series on Eucalyptus Plantations  

Directory of Open Access Journals (Sweden)

Full Text Available The leaf area index (LAI is a key characteristic of forest ecosystems. Estimations of LAI from satellite images generally rely on spectral vegetation indices (SVIs or radiative transfer model (RTM inversions. We have developed a new and precise method suitable for practical application, consisting of building a species-specific SVI that is best-suited to both sensor and vegetation characteristics. Such an SVI requires calibration on a large number of representative vegetation conditions. We developed a two-step approach: (1 estimation of LAI on a subset of satellite data through RTM inversion; and (2 the calibration of a vegetation index on these estimated LAI. We applied this methodology to Eucalyptus plantations which have highly variable LAI in time and space. Previous results showed that an RTM inversion of Moderate Resolution Imaging Spectroradiometer (MODIS near-infrared and red reflectance allowed good retrieval performance (R2 = 0.80, RMSE = 0.41, but was computationally difficult. Here, the RTM results were used to calibrate a dedicated vegetation index (called “EucVI” which gave similar LAI retrieval results but in a simpler way. The R2 of the regression between measured and EucVI-simulated LAI values on a validation dataset was 0.68, and the RMSE was 0.49. The additional use of stand age and day of year in the SVI equation slightly increased the performance of the index (R2 = 0.77 and RMSE = 0.41. This simple index opens the way to an easily applicable retrieval of Eucalyptus LAI from MODIS data, which could be used in an operational way.

Guerric le Maire

2012-11-01

97

Enhanced Vegetation Index (EVI) na análise da dinâmica da vegetação da reserva biológica de Sooretama, ES / Use of Enhanced Vegetation Index (EVI) in the analysis os vegetation dynamics of the Sooretama biological reservation, ES  

Scientific Electronic Library Online (English)

Full Text Available Técnicas de análises de séries temporais são utilizadas para caracterizar o comportamento de fenômenos naturais no domínio do tempo. Neste artigo, segundo a metodologia proposta por Box et al. (1994), 125 observações do Enhanced Vegetation Index (EVI) foram analisadas. Os valores modelados correspon [...] dem às variações temporais ocorridas no dossel florestal da reserva biológica de Sooretama, localizada ao Norte do Estado do Espírito Santo, no Município de Linhares. Os resultados indicaram que a metodologia foi adequada. Os resíduos do modelo ajustado são não correlacionados com distribuição normal, média zero e variância s². Com o menor valor do Critério de Informação de Akaike (AIC) -570,51, o modelo ajustado foi o Sazonal Auto-Regressivo Integrado de Médias Móveis (1,0,1)(1,0,1)12. Abstract in english Temporal series analysis techniques are used to characterize the behavior of natural phenomenon in time domain. In this paper, 125 Enhanced Vegetation Index (EVI) observations were analyzed according to the methodology proposed by Box et al.(1994). The values modeled correspond to the temporal varia [...] tions that occurred in the forest canopy of the Sooretama Biological Reserve, in northern Espírito Santo, in the district of Linhares. The results indicated that such methodology was adequate. The residues of the adjusted model are not correlated with normal distribution, zero average and s² variance. At the lowest value of the Akaike Information Criteria (AIC) -570. 51, the model adjusted was the Mobile Average Integrated Self-Regressive Seasonal model (1, 0, 1) (1, 0, 1)-12.

André Quintão de, Almeida; Gilson Fernandes da, Silva; José Eduardo Macedo, Pezzopane; Carlos Alexandre Damasceno, Ribeiro.

1099-11-01

98

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

International Nuclear Information System (INIS)

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 differenotential factors driving regional differences are discussed.

99

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

100

Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments  

Directory of Open Access Journals (Sweden)

Full Text Available The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene. Three water potential levels in the soil were used in order to define irrigation time, corresponding to -0.010 (N1, -0.035 (N2, and -0.070 (N3 MPa, measured through tensiometers installed at the 10 cm depth. A 2 x 3 factorial arrangement was adopted, as randomized complete block, with 5 replicates. In the protected cultivation, the irrigation levels of -0.010 and -0.035 MPa and the clear plastic mulch favored the vegetative growth, evaluated through plant height, maximum horizontal dimension of the plant, leaf area index, as well as by total marketable fruit yield and its components (mean number and weight of fruits per plant. In the open field cultivation, no effect of treatments due to rainfall were observed.

Pires Regina Célia de Matos

2006-01-01

101

Relationships between evaprorative fraction and remotely sensed vegetation index and microwave brightness temperature for semiarid rangelands  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the microwave brightness temperature (TB) with the Pushbroom Microwave Radiometer (PBMR) over the Walnut Gulch Experiment Watershed were made on selected days during the MONSOON 90 field campaign. The PBMR is an L-band instrument (21-cm wavelength) that can provide estimates of near-surface soil moisture over a variety of surfaces. Aircraft observations in the visible and near-infrared wavelengths collected on selected days also were used to compute a vegetation index. Continuous micrometeorological measurements and daily soil moisture samples were obtained at eight locations during experimental period. Two sites were instrumented with time domain reflectometry probes to monitor the soil moisture profile. The fraction of available energy used for evapotranspiration was computed by taking the ratio of latent heat flux (LE) to the sum of net radiation (Rn) and soil heat flux (G). This ratio is commonly called the evaporative fraction (EF) and normally varies between 0 and 1 under daytime convective conditions with minimal advection. A wide range of environmental conditions existed during the field campaign, resulting in average EF values for the study area varying from 0.4 to 0.8 and values of TB ranging from 220 to 280 K. Comparison between measured TB and EF for the eight locations showed an inverse relationship. Other days were included in the analysis by estimating TB with the soil moisture data. Because transpiration from the vegetation is more strongly coupled to root zone soil moisture, significant scatter in this relationship existed at high values of TB or dry near-surface soil moisture conditions.

Kustas, W.P.; Schimugge, T.J.; Humes, K.S.; Jackson, T.J.; Parry, R.; Weltz, M.A.; Moran, M.S. [USDA-ARS, Beltsville, MD (United States)]|[USDA-ARS, Tucson, AZ (United States)]|[USDA-ARS, Phoenix, AZ (United States)

1993-12-01

102

Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils  

OpenAIRE

Problem statement: Some vegetable oils contains natural antioxidants such as beta carotene and vitamin E namely tocopherol and tocotrienol. Different vegetable oils contained different amount of vitamin E and ?-carotene. Approach: Study was carried out to investigate the natural antioxidants (vitamin E and beta carotene) composition in four different vegetable oils [Red Palm Olein (RPO), palm plein (PO), Corn Oil (CO) and Coconut Oil (COC)]. Results: The results showe...

Top, Ab G. M.; Halimah Muhamad; Aminah Abdullah; Sani, Halimah A.; Eqbal Dauqan

2011-01-01

103

[A novel vegetation index (MPRI) of corn canopy by vehicle-borne dynamic prediction].  

Science.gov (United States)

Ground-based remote sensing system is a significant way to understand the growth of corn and provide accurate and scientific data for precision agriculture. The vehicle-borne system is one of the most important tools for corn canopy monitoring. However, the vehicle-borne growth monitoring system cannot maintain steady operations due to the row spacing of corn. The reflectance of corn canopy, which was used to construct the model for the chlorophyll content, was disturbed by the reflectance of soil background. The background interference with the reflectance could not be removed effectively, which would result in a deviation in the growth monitoring. In order to overcome this problem, a novel vegetation index named MPRI was developed in the present paper. The tests were carried out by the vehicle-borne system on the cornfield. The sensors which configured the vehicle-borne system had 4 bands, being respectively 550, 650, 766 and 850 nm. It would obtain the spectral data while the vehicle moved along the row direction. The sampling rate was about 1 point per second. The GPS receiver obtained the location information at the same rate. MPRI was made up by the reflectance ratio of 660 and 550 nm. It was very effective to analyze the information about the reflectance of the canopy. The results of experiments showed that the MPRI of soil was the positive value and the MPRI of canopy was the negative value. So it is easier to distinguish the spectral information about soil and corn canopy by MPRI. The results indicated that: it had satisfactory forecasting accuracy for the chlorophyll content by using the MPRI on the moving monitoring. The R2 of the prediction model was about 0.72. The R2 Of the model of NDVI, which was used to represent the chlorophyll content, was only 0.24. It indicates that MPRI had good measurement results for the dynamic measurement process. It provided the novel measurement way to get the canopy reflectance spectra and the better vegetation index to construct the prediction model of the contents of chlorophyll. PMID:25358172

Li, Shu-qiang; Li, Min-zan; Sun, Hong

2014-06-01

104

Impact of the construction of a large dam on riparian vegetation cover at different elevation zones as observed from remotely sensed data  

Science.gov (United States)

The impact of the construction of a large dam on riparian vegetation cover can be multifold. How the riparian vegetation cover changes at different elevation zones in response to the construction of a large dam and the subsequent impound of reservoir water is still an open question. In this study, we used satellite remote sensing data integrated with geographic information system (GIS) to monitor vegetation cover change at different riparian elevation zones on a large spatial scale, taking the Three Gorges Dam in China as an example. Due to the large scale of this newly formed reservoir, it is expected to impact the riparian vegetation canopy both directly and indirectly. We chose to monitor vegetation cover changes along the 100 km riparian stretch of river directly upstream of the Three Gorges Dam site, over the construction period of eleven years (2000-2010), using MODIS vegetation indices products, digital elevation model (DEM) data from ASTER, and the time series water level data of the Three Gorges reservoir as the data sources. Results show that non-vegetated area increased in the inundated zone (below 175 m), as expected; area of densely vegetated land cover increased within the elevation zone of 175-775 m and no change in vegetation cover was observed above 775 m in elevation. Regression analysis between the vegetation index data and the reservoir water level shows that increasing water levels have had a negative impact on vegetation cover below 175 m, a positive impact on vegetation cover is limited to the region between 175 and 775 m, and no significant impact was observed above 775 m. MODIS EVI product is less sensitive in mapping non-vegetated land cover change, but more sensitive in mapping vegetated land cover change, caused by the reservoir water level variation; both products are similar in effectively tracking a trend between land cover change in each elevation zone with time or with reservoir water level.

Kellogg, Christopher H.; Zhou, Xiaobing

2014-10-01

105

Bioclimatic and vegetation mapping of a topographically complex oceanic island applying different interpolation techniques  

Science.gov (United States)

Different spatial interpolation techniques have been applied to construct objective bioclimatic maps of La Palma, Canary Islands. Interpolation of climatic data on this topographically complex island with strong elevation and climatic gradients represents a challenge. Furthermore, meteorological stations are not evenly distributed over the island, with few stations at high elevations. We carried out spatial interpolations of the compensated thermicity index (Itc) and the annual ombrothermic Index (Io), in order to obtain appropriate bioclimatic maps by using automatic interpolation procedures, and to establish their relation to potential vegetation units for constructing a climatophilous potential natural vegetation map (CPNV). For this purpose, we used five interpolation techniques implemented in a GIS: inverse distance weighting (IDW), ordinary kriging (OK), ordinary cokriging (OCK), multiple linear regression (MLR) and MLR followed by ordinary kriging of the regression residuals. Two topographic variables (elevation and aspect), derived from a high-resolution digital elevation model (DEM), were included in OCK and MLR. The accuracy of the interpolation techniques was examined by the results of the error statistics of test data derived from comparison of the predicted and measured values. Best results for both bioclimatic indices were obtained with the MLR method with interpolation of the residuals showing the highest R 2 of the regression between observed and predicted values and lowest values of root mean square errors. MLR with correction of interpolated residuals is an attractive interpolation method for bioclimatic mapping on this oceanic island since it permits one to fully account for easily available geographic information but also takes into account local variation of climatic data.

Garzón-Machado, Víctor; Otto, Rüdiger; del Arco Aguilar, Marcelino José

2014-07-01

106

Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Some vegetable oils contains natural antioxidants such as beta carotene and vitamin E namely tocopherol and tocotrienol. Different vegetable oils contained different amount of vitamin E and ?-carotene. Approach: Study was carried out to investigate the natural antioxidants (vitamin E and beta carotene composition in four different vegetable oils [Red Palm Olein (RPO, palm plein (PO, Corn Oil (CO and Coconut Oil (COC]. Results: The results showed that RPO contained the highest amount of vitamin E and ?-carotene compared to the other three types of vegetable oils studied. Conclusion: The RPO can be considered as a good source of natural antioxidant (tocopherol, tocotrienol and ?-carotene.

Ab. G.M. Top

2011-01-01

107

Vegetative Growth of Four Strains of Hericium erinaceus Collected from Different Habitats  

OpenAIRE

Vegetative growth of four different strains of Hericium erinaceus was observed. The temperature suitable for optimal mycelial growth was determined to be 25?, with growth observed in the extend temperature range of 20~30?. The different strains of this mushroom showed distinct pH requirements for their optimum vegetative growth, with the most favorable growth observed at pH 6. Considering vegetative mycelial growth, PDA, YM, Hennerberg, Hamada, and Glucose peptone were the most favorable ...

Imtiaj, Ahmed; Jayasinghe, Chandana; Lee, Geon Woo; Shim, Mi Ja; Rho, Hyun-su; Lee, Hyun Sook; Hur, Hyun; Lee, Min Woong; Lee, U-youn; Lee, Tae-soo

2008-01-01

108

Differences between Sand and Gravel Bars of Streams in Patterns of Vegetation Succession  

OpenAIRE

We analyzed the factors driving succession and the structure, and dynamics of vegetation on sandand gravel bars in order to clarify the differences in vegetation succession in rivers with different river bed substrates.Woody plant communities (dominated by Salix), perennial herb communities (dominated by Miscanthus),and annual plant communities (dominated by Persicaria) appeared in that order from upstream to downstreamon the sandbar. The results of DCA ordination based on vegetation data ref...

Lee, Chang-seok; Yong-Chan Cho; Hyun-Cheol Shin; Sung-Ae Park

2009-01-01

109

Comparing forest measurements from tree rings and a space-based index of vegetation activity in Siberia  

International Nuclear Information System (INIS)

Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record. (letter)iven its relatively short record. (letter)

110

Comparing forest measurements from tree rings and a space-based index of vegetation activity in Siberia  

Science.gov (United States)

Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record.

Bunn, Andrew G.; Hughes, Malcolm K.; Kirdyanov, Alexander V.; Losleben, Mark; Shishov, Vladimir V.; Berner, Logan T.; Oltchev, Alexander; Vaganov, Eugene A.

2013-09-01

111

Comparative evaluation of the Vegetation Dryness Index (VDI), the Temperature Vegetation Dryness Index (TVDI) and the improved TVDI (iTVDI) for water stress detection in semi-arid regions of Iran  

Science.gov (United States)

This study aims at developing appropriate methods to detect water stress in the semi-arid regions of Iran. To do this, the Vegetation Dryness Index (VDI) concept, originally developed for forest fire detection, was applied to detect vegetation/soil water stress. A modified approach towards the Temperature Vegetation Dryness Index (TVDI) concept, incorporating air temperature and a Digital Elevation Model (DEM) to develop the improved TVDI (iTVDI) is also introduced and the results are compared with the original TVDI and VDI through verification by precipitation and soil moisture data. Evaluation of the VDI in the study area showed that there was no significant relationship between the VDI values and precipitation or soil moisture indicating its inappropriateness to be used for water stress detection. Compared with the TVDI, results indicated that there were more statistically significant relationships between the iTVDI and recent precipitation and soil moisture in the four land cover types in the study area. This indicates that the iTVDI is highly influenced by recent precipitation during the summer and can therefore estimate water status. It is concluded that the iTVDI can be successfully used for vegetation/soil water stress monitoring in the semi-arid regions of Iran.

Rahimzadeh-Bajgiran, Parinaz; Omasa, Kenji; Shimizu, Yo

2012-03-01

112

A MODIS-based begetation index climatology  

Science.gov (United States)

Passive microwave soil moisture algorithms must account for vegetation attenuation of the signal in the retrieval process. One approach to accounting for vegetation is to use vegetation indices such as the Normalized Difference Vegetation Index (NDVI) to estimate the vegetation optical depth. The pa...

113

Combining vegetation index and model inversion methods for theextraction of key vegetation biophysical parameters using Terra and Aqua MODIS reflectance data  

DEFF Research Database (Denmark)

Accurate estimates of vegetation biophysical variables are valuable as input to models describing the exchange of carbon dioxide and energy between the land surface and the atmosphere and important for a wide range of applications related to vegetation monitoring, weather prediction, and climate change. The present study explores the benefits of combining vegetation index and physically based approaches for the spatial and temporal mapping of green leaf area index (LAI), total chlorophyll content (TCab), and total vegetation water content (VWC). A numerical optimization method was employed for the inversion of a canopy reflectance model using Terra and Aqua MODIS multi-spectral, multi-temporal, and multi-angle reflectance observations to aid the determination of vegetation-specific physiological and structural canopy parameters. Land cover and site-specific inversion modeling was applied to a restricted number of pixels to build multiple species- and environmentally dependent formulations relating the three biophysical properties of interest to a number of selected simpler spectral vegetation indices (VI). While inversions generally are computationally slow, the coupling with the simple and computationally efficient VI approach makes the combined retrieval scheme for LAI, TCab, and VWC suitable for large-scale mapping operations. In order to facilitate application of the canopy reflectance model to heterogeneous forested areas, a simple correction scheme was elaborated, which was found to improve forest LAI predictions significantly and also provided more realistic values of leaf chlorophyll contents. The inversion scheme was designed to enable biophysical parameter retrievals for land cover classes characterized by contrasting canopy architectures, leaf inclination angles, and leaf biochemical constituents without utilizing calibration measurements. Preliminary LAI validation results for the Island of Zealand, Denmark (57°N, 12°E) provided confidence in the approach with root mean square (RMS) deviations between estimates and in-situ measurements of 0.62, 0.46, and 0.63 for barley, wheat, and deciduous forest sites, respectively. Despite the independence on site-specific in-situ measurements, the RMS deviations of the automated approach are in the same range as those established in other studies employing field-based empirical calibration. Being completely automated and image-based and independent on extensive and impractical surface measurements, the retrieval scheme has potential for operational use and can quite easily be implemented for other regions. More validation studies are needed to evaluate the usefulness and limitations of the approach for other environments and species compositions.

Houborg, Rasmus MØller; SØgaard, Henrik

2007-01-01

114

Soil moisture status estimation over Three Gorges area with Landsat TM data based on temperature vegetation dryness index  

Science.gov (United States)

Soil moisture is the important indicator of climate, hydrology, ecology, agriculture and other parameters of the land surface and atmospheric interface. Soil moisture plays an important role on the water and energy exchange at the land surface/atmosphere interface. Remote sensing can provide information on large area quickly and easily, so it is significant to do research on how to monitor soil moisture by remote sensing. This paper presents a method to assess soil moisture status using Landsat TM data over Three Gorges area in China based on TVDI. The potential of Temperature- Vegetation Dryness Index (TVDI) from Landsat TM data in assessing soil moisture was investigated in this region. After retrieving land surface temperature and vegetation index a TVDI model based on the features of Ts-NDVI space is established. And finally, soil moisture status is estimated according to TVDI. It shows that TVDI has the advantages of stability and high accuracy to estimating the soil moisture status.

Xu, Lina; Niu, Ruiqing; Li, Jiong; Dong, Yanfang

2011-12-01

115

Non-Lambertian Corrected Albedo and Vegetation Index for Estimating Land Evapotranspiration in a Heterogeneous Semi-Arid Landscape  

OpenAIRE

The application of energy balance algorithms to remotely sensed imagery often fails to account for surface roughness variation with diverse land cover, resulting in poor resolution of evapotranspiration (ET) variations. Furthermore, the assumption of a horizontally homogeneous Lambertian surface reflecting energy equally in all directions affects the calculations of albedo and vegetation index. The primary objective of this study is to improve the accuracy of the estimation and discrimination...

Isabella Mariotto; Gutschick, Vincent P.

2010-01-01

116

Impact of consumption of vegetable, fruit, grain, and high glycemic index foods on aggressive prostate cancer risk.  

Science.gov (United States)

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing the highest to lowest quartiles of intake, we found that increasing intakes of leafy vegetables were inversely associated with risk of aggressive prostate cancer [adjusted odds ratio (OR) = 0.66, 95% CI: 0.46, 0.96; P trend = 0.02], as was higher consumption of high carotenoid vegetables (OR = 0.71, 95% CI: 0.48, 1.04; P trend = 0.04). Conversely, increased consumption of high glycemic index foods were positively associated with risk of aggressive disease (OR = 1.64, 95% CI: 1.05, 2.57; P trend = 0.02). These results were driven by a number of specific foods within the food groups. Our findings support the hypothesis that diets high in vegetables and low in high glycemic index foods decrease risk of aggressive prostate cancer. PMID:21774611

Hardin, Jill; Cheng, Iona; Witte, John S

2011-01-01

117

Accuracy of the Temperature-Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions  

DEFF Research Database (Denmark)

Water deficit indices based on the spatial relationship between surface temperature (Ts) and NDVI, known as triangle approaches, are widely used for drought monitoring. However, their application has been recently questioned when the main factor limiting evapotranspiration is energy. Even though water is the main control in dryland ecosystems, these can also undergo periods of energy and temperature limitation. In this paper we aimed to: (i) evaluate the TVDI (Temperature-Vegetation Dryness Index) to estimate water deficits (e.g. ratio between actual and potential evapotranspiration), and heat surface fluxes using MODIS data; and (ii) provide insights about the factors most affecting the accuracy of results. Factors considered included the type of climatic control on evapotranspiration, ?E, (i.e. water-limited vs. energy-limited), the quality of Tair estimates, the heterogeneity of land cover types and climatic variables in the region, or the algorithm to extract hydrological boundaries from the images. The TVDI was compared with eddy covariance (EC) data from two shrublands with different climatic controls for ?E in South Spain. Evaluations showed that it could be used to estimate the water deficit when water was the main limiting factor (R=0.81-0.88; Mean Average Error, MAE=0.16-0.17) but not in energy-limited situations (R

Garcia, Monica; Ferna?ndez, N.

2014-01-01

118

Seasonal analysis of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data  

Science.gov (United States)

Paddy field is important agriculture crop in Indonesia. Rice is a food staple for 237,6 million Indonesian people. Paddy field growth is strongly influenced by water, but the amount of precipitation is unpredictable. Annual and interannual climate variability in Indonesia is unusual. In recent years remote sensing data has been used for measurement and monitoring of precipitation, drought and Vegetation index such as Global Satellite Mapping of Precipitation (GSMaP), Multi-purpose Transmission SATellite (MTSAT) and Moderate Resolution Imaging Spectroradiometer (MODIS). The objective of this research is to investigate seasonal variability of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data. The methodology consists of collecting of enhanced vegetation index (EVI) from MODIS data, mosaicking of image, collecting of region of interest of paddy field, collecting of precipitation and drought index based on Keetch Bryam Drought Index (KBDI) from GSMaP and MTSAT, and seasonal analysis. The result of this research has showed seasonal variability of precipitation, KBDI and EVI on Indonesia paddy field from 2007 until 2012. Precipitation begins from January until May and October until December, and KBDI begins to increase from June and peak in September only in South Sumatera precipitation almost in all month. Seasonal analysis has showed precipitation and KBDI affect on EVI that can indicate variety phenology of Indonesian paddy field. Peak of EVI occurs before peak of KBDI occurs and increasing of KBDI followed by decreasing of EVI. In 2010 all province got higher precipitation and smaller KBDI so EVI has three peaks such as in West Java that can indicated increasing of rice production.

Darmawan, S.; Takeuchi, W.; Shofiyati, R.; Sari, D. K.; Wikantika, K.

2014-06-01

119

Differences in the dry deposition of gaseous elemental I-131 to several leafy vegetable species  

International Nuclear Information System (INIS)

The height of the dry deposition of gaseous elemental 131I to leafy vegetable is quite uncertain because of the different habit, surface texture and leaf uptake of the different plant species. There is no comparative data on the deposition to various species, but leafy vegetables are taken as reference plants for the estimation of the height of contamination of vegetable foods after a nuclear accident. Therefore new chamber experiments were performed to determine under homogeneous and controlled conditions the dry deposition of gaseous elemental 131I on mature leafy vegetable. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce and spinach (spring leafy vegetable) rsp. curly kale, white cabbage and spinach (summer leafy vegetable) was arranged. The sample collective of each species was such large that for the expected variation of the results a statistically firm analysis was possible. Significant differences were observed for the 131I deposition on spring vegetable: the deposition on spinach was roughly 3 times that on leaf lettuce, 4 times that on endive and 9 times that on head lettuce. All summer vegetables showed differences in deposition. For Iodine, the deposition on spinach was roughly 3 times (6 times) that on curly kale and 35 times (100 times) that on white cabbage in the 2 experiments. Washing by deionised water could reduce the contamination only by about 10% for 131I. (author)

120

Estimating riparian and agricultural actual evapotranspiration by reference evapotranspiration and MODIS Enhanced Vegetation Index  

Science.gov (United States)

Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in these districts. We developed a general algorithm for estimating actual evapotranspiration (ETa) based on the ...

121

Differences between Sand and Gravel Bars of Streams in Patterns of Vegetation Succession  

Directory of Open Access Journals (Sweden)

Full Text Available We analyzed the factors driving succession and the structure, and dynamics of vegetation on sandand gravel bars in order to clarify the differences in vegetation succession in rivers with different river bed substrates.Woody plant communities (dominated by Salix, perennial herb communities (dominated by Miscanthus,and annual plant communities (dominated by Persicaria appeared in that order from upstream to downstreamon the sandbar. The results of DCA ordination based on vegetation data reflected a successional trend. Thisresult suggests that sandbars grow in a downstream direction. Various vegetation types different in successionalstage, such as grassland, young stands of Korean red pine (Pinus densiflora, two-layered stands of young andmature pines, and mature pine stands also occurred on gravel bars, but the vegetation in earlier successionalstage was established upstream, which is the opposite to the direction found on sandbars. Those resultsdemonstrate that the dynamics of the bed load itself could be a factor affecting vegetation succession in rivers.In fact, sands suspended by running water were transported downstream over the vegetated area of sand barand thereby created new areas of sandbar on the downstream end of the sandbar. Meanwhile, gravel, whichis heavy and thereby is shifted by strong water currents, accumulated on the upstream end of the vegetatedarea, and thus created new areas of gravel bar in that direction. These results showed that allogenic processesdrive vegetation succession on sand and gravel bars in streams and rivers.

Lee, Chang-Seok

2009-02-01

122

Soil borne gungi associated with different vegetable crop in sindh, pakistan  

International Nuclear Information System (INIS)

Different soil-borne fungi are responsible for reducing the yield of vegetables throughout the world including Pakistan. There are several soil borne fungal pathogens which aggressively infect vegetable crops. Surveys conducted during September 2010 to October 2011, demonstrated that a great diversity of soil borne plant pathogens associated with different vegetables prevail in vegetable growing areas of Sindh such as Tando Allahayar, Mirpurkhas, Ghotaki, Khairpur, Kunri, Umerkot and Karachi, etc. Our study noted in total thirteen different genera of fungi isolated from vegetable crops (cabbage, brinjal, tomato, radish and spinach). Isolated fungi identified included Alternaria solani, Aspergillus flavus, A. fumigatus, A. niger, A. oryzae, A. terrus, Aeromonium fusidiocles, Cladosporium sp., Drechselra hawaiiensis, Eurotium berbanbrum, Fusarium oxysporum, Macrophomina phaseolina, Penicillium commune, Rhizoctonia solani, Trichoderma harzianum, Ulocladium sp., and unidentified black mycelium from the soil and roots of vegetable crops. In addition, it was found that soil is commonly infected by soil-borne fungi and eventually results in heavy losses of vegetable yield in the vegetable growing areas of Sindh province. The infection rapidly increased due to many factors such as, presence of moisture, excess of water and infection may be caused by winds, gales and dust storms as well as by mechanical vectors. (author)

123

High Resolution Temporal Normalized Difference Vegetation Indices for Specific Crop Identification  

Science.gov (United States)

In many applications of the remote sensing, an user is often interested in identifying specific land cover only while other classes may be of no interest. In the present study, high resolution WorldView-2 image having spatial resolution of 1.84 meter has been used for identifying wheat crop for a test site located in Roorkee, India. WorldView-2 data consists of a total of eight spectral bands out of which last four spectral bands i.e. Red (630-690 nm), Red edge (705-745 nm), NIR 1 (770-895 nm) and NIR 2 (860-1040 nm) are useful for the vegetation related studies. Since Normalized Difference Vegetation Index (NDVI) which is formulated by the Red and NIR band, is well known for vegetation related studies. Therefore, in the present research the above four bands has been used to generate all the four possible combinations of NDVI viz. Red - NIR1, Red edge - NIR 1, Red - NIR 2 and Red edge - NIR 2. Further to study the temporal behaviour of crops, two date WorldView-2 data was taken to make the temporal NDVI. These temporal NDVI were then classified using fuzzy based Possibilistic c-Means (PCM) soft classification. The weighting exponent (or fuzzifier) m was optimized to get the best PCM soft classification output. Wheat crop is represented as the fraction image output of the PCM soft classification corresponding to each temporal NDVI. To check the accuracy of these fraction images, the entropy method was used. The entropy values were calculated for a total of 150 known pixels in each output. It is found that the outputs corresponding to low entropy values have sufficiently high membership values for wheat class, hence these outputs are more accurate. Further, it is observed that the average entropy values found for the temporal NDVI corresponding to the Red - NIR 1, Red edge - NIR 1, Red - NIR 2 and Red edge - NIR 2 are 0.065, 0.089, 0.075 and 0.055 respectively. Thus, it can be concluded that temporal NDVI generated by using a combination of Red edge and NIR-2 bands yields higher accuracies in comparison to other. It was also observed from the study that the optimized values of weighting exponent m is varies for different spectral indices.

Upadhyay, P.; Ghosh, S. K.; Kumar, A.

2013-05-01

124

A survey of drought and Variation of Vegetation by statistical indexes and remote sensing (Case study: Jahad forest in Bandar Abbas)  

Science.gov (United States)

The damages of drought as a climatic and creeping phenomenon are very enormous specially in deserts. Necessity of management and conflict with it is clear. In this case vegetation are damaged too, and even are changed faster. This paper describes the process of vegetation changes and surveys it with drought indexes such as statistical and remote sensing indexes and correlation between temperature and relative humidity by Geographical Information System (GIS) and Remote Sensing (RS) in forest park of Bandar Abbas in successive years. At the end the regression and determination-coefficient for showing the importance of droughts survey are computed. Results revealed that the correlation between vegetation and indexes was 0.5. The humidity had maximum correlation and when we close to 2009 the period of droughts increase and time intervals decrease that influence vegetation enormously and cause the more area lost its vegetation.

Tamassoki, E.; Soleymani, Z.; Bahrami, F.; Abbasgharemani, H.

2014-06-01

125

Plasma Electrophoresis and Phagocytic Index Screening of Some Indigenous Vegetables Subjected to Preclinical Models  

Directory of Open Access Journals (Sweden)

Full Text Available

50 % of methanolic extract Colocasia esculenta, Moringa oliefera, Luffa cylindrica, and Hibiscus esculentus were subjected to immunomodulatory activity in Swiss albino mice either sex. Mice were treated with five days of dosing of Colocasia esculenta 50 mg/kg bw, Colocasia esculenta 100 mg/kg bw, Moringa oliefera 200mg/kg bw, Moringa oleifera 400 mg/kg bw, Luffa cylindrica 100 mg/kg bw, Luffa cylindrica 200 mg/kg bw, Hibiscus esculentus 100 mg/kg bw, and Hibiscus esculentus 200 mg/kg bw. Cyclosporine (2.5 mg/kg used as a standard reference drug for 5 days. Investigation of immunomodulator activity of these 50 % of methanolic extract of drugs to parentage of yeast digestion form 24 hours the peritoneal fluid culture and electrophoretic plasma protein band albumin, alpha 1, alpha 2, beta and gamma respectively from blood plasma were observed using parameters phagocytosis and plasma electrophoresis. Also investigated the ulcerogenic effect or any toxic effect of plant extract by histopathology study of crypt, villi and goblet cells with reference to standard drug cyclosporine. As regards these parameters, Hibiscus esculentus 100 and 200 mg/ kg bw dose, Moringa oleifera 200 and 400 mg/ kg bw dose and Luffa cylindrica 200mg/kg bw elicited a moderately significant increase in the % of yeast digestion (P < 0.001 respectively and Luffa cylindrica 100mg/kg bw significant increase in the % of yeast digestion (P < 0.01. Hibiscus esculentus showed significant dose dependent increase and Moringa oleifera decrease phagocytic activity of macrophages. Hibiscus esculentus 200 mg/ kg bw dose and Moringa oleifera 200 significantly increased (P < 0.01 the Gamma globulin.However, our present study revealed and signatured for their immunomodulator enhancing property. As in Asian subcontinent daily there vegetables are cooked and served with know and unknown of its potential function against different diseases. If there vegetables properly ruled out for their pharmacological aspect then it may add diamond in the crown of dietician which has been bother every day today life but over looked exponetentially.

Keywords:- Colocasia esculenta, Moringa oliefera, Luffa cylindrica, and Hibiscus esculentus

Vikas Sharma

2011-04-01

126

Experiments of hydraulics mechanics through different arrangement of submerged bending vegetation  

Science.gov (United States)

Laboratory experiments are used to explore the effect of different arrangement of submerged bending vegetation in the fixed bed on flow field around vegetation and area downstream. The two simulated bending vegetation were composed of pipe curved to 90 degree for stems and P.P.C films for blades. The two bending vegetation were arranged in alignment and paralleled with flow direction. The test arrangement was distinguished by different overlap rate of vegetation. Overlap rate of vegetation were defined that percentage of blades of bending vegetation overlap the other one. Overlap rate is greater than zero and it means that vegetation overlap the other one. On the other hand, overlap rate is smaller than zero and it means that two plants were separated in percentage of total length of vegetation The experiments were carried out 10 test in forms of overlap rate of vegetation (50%, 25%, 0%,-25%,-50%) by blades of 20cm and 25cm.Velocity and turbulence intensity around the vegetation (u, v, w and urms, vrms, wrms) were acquired by Ultrasound Velocity Profiler (UVP). Furthermore, to elaborate variation of the flow field, the swinging motion of vegetation was recorded by digital camera. Three arrangement types (overlapped, continuous and isolated) were concluded from the 10 tests. In case of isolated vegetation, it could be observed that there was a better effect on slowing flow velocity in x direction in case of the tests with -25% overlap rate due to a discontinuous shear layer between two plants which induced wake interference. It also showed that turbulence intensity was significant between two plants. Two plants disturbed rarely each other in the tests of isolated vegetation with -50% overlap rate .Flow was disturbed by swinging of blades only and returned to stable quickly. In 25% and 50% tests, two plants were overlapped and their behavior was similar to a longer blades plant. Its blades swinging were not obvious result as low effect on slowing velocity in x direction. It means that the characteristic of overlapped vegetation is good for stabilizing the flow field. The research helped to realize influence between two plants on flow field in order to apply river system management strategies.

Chen, Ye-Hong; Chen, Su Chun

2014-05-01

127

DEVELOPMENT OF AN INDEX OF ALIEN SPECIES INVASIVENESS: AN AID TO ASSESSING RIPARIAN VEGETATION CONDITION  

Science.gov (United States)

Many riparian areas are invaded by alien plant species that negatively affect native species composition, community dynamics and ecosystem properties. We sampled vegetation along reaches of 31 low order streams in eastern Oregon, and characterized species assemblages at patch an...

128

Diseño de índices espectrales de la vegetación usando curvas iso-suelo / Design of spectral vegetation indexes using iso-soil curves  

Scientific Electronic Library Online (English)

Full Text Available El diseño de índices espectrales de la vegetación (IV) basados en las líneas iso-índice de área foliar (misma cantidad de vegetación y propiedades ópticas diferentes de los suelos debajo de la vegetación) en el ancho de banda del rojo (R) e infrarrojo cercano (IRC) del espectro electromagnético, res [...] ulta complejo por el patrón expo-lineal con cambio de pendiente, entre los parámetros que definen estas líneas. Una alternativa de diseño es considerar los patrones de las curvas iso-suelo (mismo suelo y cantidad variable de vegetación), usando el IRC como banda de saturación más lenta posible. El índice IVIS (IV basado en las curvas iso-suelo) introducido permite este tipo de aproximación, al usar una transformación del espacio de R para hacerlo coincidir con la línea del suelo y una estructura matemática similar a índices uni-banda espectral. La validación de IVIS usando simulaciones radiativas y de experimentos con cultivos generó resultados aceptables, particularmente con una óptica de minimización del efecto del suelo en escala píxel por píxel. La transformación de IVIS permite la parametrización de la curva de crecimiento en formato lineal, simple de implementar en términos algorítmicos. Abstract in english The design of spectral vegetation indexes (VI) based on the lines iso-leaf area index (same amount of vegetation and different optical properties of the soils under the vegetation) in two bands of the electromagnetic spectrum, the red (R) and near-infrared (NIR), is complicated because of the expoli [...] near pattern with change of slope, among the parameters that define these lines. An alternative design is to consider the patterns of iso-soil curves (same soil, and varying amounts of vegetation), using the NIR as a saturation band as slow as possible. The introduced index ISVI (VI based on the iso-soil curves) allows this type of approach, by using a transformation of the space of R to make it coincide with the soil line and a mathematical structure similar to uni-band spectral indexes. ISVI validation using radiative simulations and crop experiments produced acceptable results, particularly with a perspective of minimizing the soil effect at píxel by píxel scale. The transformation of the ISVI allows parameterization of the growth curve in a linear format, simple to implement in algorithmic terms.

Fernando, Paz-Pellat; Marisol, Reyes; Edgardo, Mediano.

2011-02-01

129

Satellite-derived leaf-area-index and vegetation maps as input to global carbon cycle models - A hierarchical approach  

Science.gov (United States)

A hierarchical procedure for developing a leaf area index (LAI) map of deciduous boreal forests is studied. The collection of spectral reflectance data from the Boundary Waters Canoe area in Minnesota using helicopter-, high-altitude aircraft-, and Landsat-mounted spectral sensors is described. The relationship between LAI and biomass and the reflectance ratio is analyzed. The sensitivity of canopy reflectance in the visible and infrared to the LAI of the canopy for various boreal forest species is evaluated. The data reveal that Landsat data are useful for producing LAI maps of deciduous forest areas and the maps provide data which clarifies the function of vegetation in the global carbon cycle models.

Badhwar, G. D.; Macdonald, R. B.; Mehta, N. C.

1986-01-01

130

Reestablishment of wetland vegetation on gas pipeline rights-of-way in six different wetland ecosystems  

Energy Technology Data Exchange (ETDEWEB)

Vegetational surveys were carried out to compare reestablished vegetation on pipeline rights-of-way (ROWS) with that in adjacent natural ecosystems undisturbed by pipeline installation. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the ROW approximated or exceeded those in the adjacent natural area. In four ecosystems, the vegetation on the ROW was limited to a herbaceous layer by ROW maintenance; thus, the ROWs often involved a complex of species quite different from that found in the adjacent ecosystems.

Zimmerman, R.E. Shem, L.; Wilkey, P.L. [Argonne National Lab., IL (United States); Van Dyke, G.D. [Trinity Christian Coll. Palos Heights, IL (United States); Hackney, C. [North Carolina Univ., Wilmington, NC (United States); Gowdy, M. [Institute of Technology, Chicago, IL (United States)

1992-05-01

131

Vegetative Growth of Four Strains of Hericium erinaceus Collected from Different Habitats.  

Science.gov (United States)

Vegetative growth of four different strains of Hericium erinaceus was observed. The temperature suitable for optimal mycelial growth was determined to be 25?, with growth observed in the extend temperature range of 20~30?. The different strains of this mushroom showed distinct pH requirements for their optimum vegetative growth, with the most favorable growth observed at pH 6. Considering vegetative mycelial growth, PDA, YM, Hennerberg, Hamada, and Glucose peptone were the most favorable media, and Czapek Dox, Hoppkins, Glucose tryptone, and Lilly were the most unfavorable media for these mushroom strains. With the exception of lactose, most of the carbon sources assayed demonstrated favorable vegetative growth of H. erinaceus. For mycelial growth, the most suitable nitrogen source was alanine and the most unsuitable was histidine. Oak sawdust medium supplemented with 10~20% rice bran was the best for mycelial growth of the mushroom. PMID:23990739

Imtiaj, Ahmed; Jayasinghe, Chandana; Lee, Geon Woo; Shim, Mi Ja; Rho, Hyun-Su; Lee, Hyun Sook; Hur, Hyun; Lee, Min Woong; Lee, U-Youn; Lee, Tae-Soo

2008-06-01

132

Multiscale geostatistical analysis of sampled above-ground biomass and vegetation index products from HJ-1A/B, Landsat, and MODIS  

Science.gov (United States)

The spatial scaling of satellite data is faced widely and inevitably in remote sensing applications for the spatial heterogeneity of ecosystems. In this study variogram analysis was used to evaluate the spatial variability and the scale effects of the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) from Huanjing (that is, environment satellite sensor in Chinese, HJ-1A/B), Landsat-5 Thematic Mapper (TM), Moderate Resolution Imaging Spectroradiometer (MODIS) 250 m, 500 m, 1 km, and the field sampled above-ground biomass (AGB). Results show that the overall spatial variance decreased when pixel size increased from 30 m (HJ and TM) to 1 km (MODIS) at the area of 10 km × 10 km. The value of 1 or 3×3 pixels approximately represent the above-ground biomass from the cyclic sampling design. This indicates that the HJ data can be used to retrieve the biomass and its scaling-up for its performance comparable with Landsat TM data, though both sensors were applicable than that of MODIS. Further the method to scale-up is a fundament approach to the validation and application of MODIS products and ecosystem model's outputs on regional scale.

Wang, Junbang; Sun, Wenyi

2014-11-01

133

Indexed  

CERN Document Server

Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

Hagy, Jessica

2008-01-01

134

SPECIES COMPOSITION OF WEED VEGETATION IN DIFFERENT APPLE GROWING TECHNOLOGIES  

Directory of Open Access Journals (Sweden)

Full Text Available The investigation was carried out in the period 2001-2003 in an orchard of the Institute of Agriculture, Kyustendil, Bulgaria, created in the spring of 1996 on leached cinnamonic forest soil. The weed populations under four different farming technologies of growing of apple cultivar Florina were investigated. It was established, that the apple growing technologies influence the weed association composition. The highest weed diversity was found in the organic technology - 16 weed species were found. In the application of resource economical and integrated technologies, the development of 13-14 weed species was established. The smallest weed diversity was observed in the conventional technology - eight species, which was due to the twofold herbicide application.

Venera TASSEVA

2005-08-01

135

Efficient retrieval of vegetation leaf area index and canopy clumping factor from satellite data to support pollutant deposition assessments  

International Nuclear Information System (INIS)

Canopy leaf area index (LAI) is an important structural parameter of the vegetation controlling pollutant uptake by terrestrial ecosystems. This paper presents a computationally efficient algorithm for retrieval of vegetation LAI and canopy clumping factor from satellite data using observed Simple Ratios (SR) of near-infrared to red reflectance. The method employs numerical inversion of a physics-based analytical canopy radiative transfer model that simulates the bi-directional reflectance distribution function (BRDF). The algorithm is independent of ecosystem type. The method is applied to 1-km resolution AVHRR satellite images to retrieve a geo-referenced data set of monthly LAI values for the conterminous USA. Satellite-based LAI estimates are compared against independent ground LAI measurements over a range of ecosystem types. Verification results suggest that the new algorithm represents a viable approach to LAI retrieval at continental scale, and can facilitate spatially explicit studies of regional pollutant deposition and trace gas exchange. - The paper presents a physics-based algorithm for retrieval of vegetation LAI and canopy-clumping factor from satellite data to assist research of pollutant deposition and trace-gas exchange. The method is employed to derive a monthly LAI dataset for the conterminous USA and verified at a continental scale

136

Urban Vegetation Cover and Vegetation Change in Accra, Ghana: Connection to Housing Quality  

OpenAIRE

The objectives are to (1) quantify, map, and analyze vegetation cover distributions and changes across Accra, Ghana, for 2002 and 2010; and (2) examine the statistical relationship between vegetation cover and a housing quality index (HQI) for 2000 at the neighborhood level. Pixel-level vegetation cover maps derived using threshold classification of 2002 and 2010 QuickBird normalized difference vegetation index images have very high overall accuracies and yield an estimate of 5.9 percent vege...

Stow, Douglas A.; Weeks, John R.; Toure, Sory; Coulter, Lloyd L.; Lippitt, Christopher D.; Ashcroft, Eric

2012-01-01

137

[Comparison of soil fertility among open-pit mine reclaimed lands in Antaibao regenerated with different vegetation types].  

Science.gov (United States)

Re-vegetation is mainly applied into regeneration in opencast mine to improve the soil quality. It is very important to choose feasible vegetation types for soil restoration. In this study, three typical forest restoration types were studied at Antaibao mine, namely, Medicago sativa, mixed forests Pinus taebelaefolius-Robinia pseudoacacia-Caragana korshinskii and Elaeagnus angustifolia-Robinia pseudoacacia-Caragana korshinskii-Hipophae rhamnoides, to determine the nutrient contents and enzyme activities in different soil layers. The results showed that re-vegetation markedly increased soil nutrient contents and the enzyme activities during the restoration process. The nutrient content of soil in the P. taebelaefolius-R. pseudoacacia-C. korshinskii mixed forest field was significantly higher than those in other plots. It was found that the soil of the P. taebelaefolius-R. pseudoacacia-C. korshinskii mixed forest had the highest integrated fertility index values. In conclusion, the restoration effects of the P. zaebelaefolius-R. pseudoacacia-C. Korshinskii mixed forest was better than that of E. angustifolia-R. pseudoacacia-C. korshinskii-H. rhamnoides, while M. sativa grassland had the least effect. PMID:24289011

Wang, Xiang; Li, Jin-chuan; Yue, Jian-ying; Zhou, Xiao-mei; Guo, Chun-yan; Lu, Ning; Wang, Yu-hong; Yang, Sheng-quan

2013-09-01

138

Evaluation of CMIP5 earth system models in reproducing leaf area index and vegetation cover over the Tibetan Plateau  

Science.gov (United States)

The abilities of 12 earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to reproduce satellite-derived vegetation biological variables over the Tibetan Plateau (TP) were examined. The results show that most of the models tend to overestimate the observed leaf area index (LAI) and vegetation carbon above the ground, with the possible reasons being overestimation of photosynthesis and precipitation. The model simulations show a consistent increasing trend with observed LAI over most of the TP during the reference period of 1986-2005, while they fail to reproduce the downward trend around the headstream of the Yellow River shown in the observation due to their coarse resolutions. Three of the models: CCSM4, CESM1-BGC, and NorESM1-ME, which share the same vegetation model, show some common strengths and weaknesses in their simulations according to our analysis. The model ensemble indicates a reasonable spatial distribution but overestimated land coverage, with a significant decreasing trend (-1.48% per decade) for tree coverage and a slight increasing trend (0.58% per decade) for bare ground during the period 1950-2005. No significant sign of variation is found for grass. To quantify the relative performance of the models in representing the observed mean state, seasonal cycle, and interannual variability, a model ranking method was performed with respect to simulated LAI. INMCM4, bcc-csm-1.1m, MPI-ESM-LR, IPSL CM5A-LR, HadGEM2-ES, and CCSM4 were ranked as the best six models in reproducing vegetation dynamics among the 12 models.

Bao, Yan; Gao, Yanhong; Lü, Shihua; Wang, Qingxia; Zhang, Shaobo; Xu, Jianwei; Li, Ruiqing; Li, Suosuo; Ma, Di; Meng, Xianhong; Chen, Hao; Chang, Yan

2014-12-01

139

Evaluating and predicting the oxidative stability of vegetable oils with different fatty acid compositions.  

Science.gov (United States)

The aim of this research was to evaluate the oxidative stabilities and qualities of different vegetable oils (almond, blend 1-8, camellia, corn, palm, peanut, rapeseed, sesame, soybean, sunflower, and zanthoxylum oil) based on peroxide value (PV), vitamin E content, free fatty acid, and fatty acid composition. The vegetable oils with different initial fatty acid compositions were studied under accelerated oxidation condition. It showed that PV and n-3 polyunsaturated fatty acid (PUFA) changed significantly during 21 d accelerated oxidation storage. Based on the changes of PV and fatty acid composition during the oxidation process, mathematical models were hypothesized and the models were simulated by Matlab to generate the proposed equations. These equations were established on the basis of the different PUFA contents as 10% to 28%, 28% to 46%, and 46% to 64%, respectively. The simulated models were proven to be validated and valuable for assessing the degree of oxidation and predicting the shelf life of vegetable oils. PMID:23527564

Li, Hongyan; Fan, Ya-wei; Li, Jing; Tang, Liang; Hu, Jiang-ning; Deng, Ze-yuan

2013-04-01

140

Antioxidant Contents (Vitamin C of Raw and Blanched Different Fresh Vegetable Samples  

Directory of Open Access Journals (Sweden)

Full Text Available The study was aimed to determine the antioxidant contents and the effect of different blanching times (5 min, 10 min, 15 min and 20 min on antioxidant contents of three different selected fresh vegetables. Three different types of vegeta- ble were used namely Amaranthus specie locally known as spinach, namely “tete”, (Celosia argentea, soko, (Solonum nodifiorum and odu, (Telfeira occidentalis were analyzed for their antioxidant contents. The analysis revealed that raw vegetables have the highest amount of antioxidant contents. Telferia occidentalis had the highest antioxidant content followed by Solonum nodifiorum. It was observed that blanching time had an adverse effect on the antioxidant contents of the blanched vegetables. The antioxidant contents of tete, soko and odu were significantly decreased (p < 0.05 after blanching.

Isaac B. Ariyo

2012-01-01

141

[Physicochemical and biological characteristics of coastal saline soil under different vegetation cover].  

Science.gov (United States)

Taking seven plots of coastal saline soil under different vegetation cover in North Jiangsu as study sites, this paper studied the seasonal fluctuations of soil basic physicochemical and biological characteristics, and analyzed the relationships between these fluctuations and vegetation cover. In the test plots, there was a greater variability of soil basic physicochemical and biological characteristics. The average soil electrical conductivity was lower in crop plots (0.95 dS m(-1)) than in natural vegetation plots (2.77 dS m(-1)), but parts of the crop plots showed an increased soil electrical conductivity compared with pre-planting. Overall, the soil fertility of the plots was generally at a low level, with the hydrolysable nitrogen content averagely lower than 50 mg kg(-1), available phosphorus content (except fertilized plots) lower than 3 mg kg(-1), and organic matter content less than 1%. Due to fertilization, the soil conditions in crop plots somewhat improved. For the test coastal saline soil, its electrical conductivity and nutrient level were the key factors affecting the vegetation distribution and plant growth, and soil electrical conductivity was most important. There existed close correlations between soil nitrogen and phosphorus contents and soil microbial amount. The seasonal fluctuations of soil characteristics were closely related with vegetation type and human disturbance, being relatively stable under higher vegetation coverage and lesser human disturbance, and dramatic in bare land and castor experimental plots. PMID:21774319

Zhou, Jian; Li, Gang; Zhou, Jian; Qin, Pei

2011-04-01

142

A New Equation for Deriving Vegetation Phenophase from Time Series of Leaf Area Index (LAI Data  

Directory of Open Access Journals (Sweden)

Full Text Available Accurately modeling the land surface phenology based on satellite data is very important to the study of vegetation ecological dynamics and the related ecosystem process. In this study, we developed a Sigmoid curve (S-curve function by integrating an asymmetric Gaussian function and a logistic function to fit the leaf area index (LAI curve. We applied the resulting asymptotic lines and the curvature extrema to derive the vegetation phenophases of germination, green-up, maturity, senescence, defoliation and dormancy. The new proposed S-curve function has been tested in a specific area (Shangdong Province, China, characterized by a specific pattern in leaf area index (LAI time course due to the dominant presence of crops. The function has not yet received any global testing. The identified phenophases were validated against measurement stations in Shandong Province. (i From the site-scale comparison, we find that the detected phenophases using the S-curve (SC algorithm are more consistent with the observations than using the logistic (LC algorithm and the asymmetric Gaussian (AG algorithm, especially for the germination and dormancy. The phenological recognition rates (PRRs of the SC algorithm are obviously higher than those of two other algorithms. The S-curve function fits the LAI curve much better than the logistic function and asymmetric Gaussian function; (ii The retrieval results of the SC algorithm are reliable and in close proximity to the green-up observed data whether using the AVHRR LAI or the improved MODIS LAI. Three inversion algorithms shows the retrieval results based on AVHRR LAI are all later than based on improved MODIS LAI. The bias statistics reveal that the retrieval results based on the AVHRR LAI datasets are more reasonable than based on the improved MODIS LAI datasets. Overall, the S-curve algorithm has the advantage of deriving vegetation phenophases across time and space as compared to the LC algorithm and the AG algorithm. With the SC algorithm, the vegetation phenophases can be extracted more effectively.

Mingliang Che

2014-06-01

143

Internalisation of Microbes in Vegetables: Microbial Load of Ghanaian Vegetables and the Relationship with Different Water Sources of Irrigation  

OpenAIRE

The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and so...

Jonathan Quaye; Kayang, Boniface B.; Lanyo, R.; Donkor, Eric S.; Edoh, Dominic A.

2010-01-01

144

The sensitivity based estimation of leaf area index from spectral vegetation indices  

Science.gov (United States)

The performances of seven spectral vegetation indices (SVIs) were investigated for their sensitivity to a varying range of LAI. The evaluation was carried out for a dataset collected using SPOT 5 HRG 10 m imagery and simulated spectra using PROSPECT + SAIL reflectance models with varying soil reflectance backgrounds. The aim was to evaluate the applicability of multiple SVIs for LAI mapping based on the sensitivity analysis. The main sensitivity function was the first derivative of the regression function divided by the standard errors of the SVIs. In addition, the sensitivity of individual band and SVI with LAI was carried out using the ordinary least squares regressions. A new SVI, reduced infrared simple ratio (RISR) was developed based on an empirical red modification to infrared simple ratio (ISR) SVI. The new SVI was demonstrated which has significantly reduced the effect of soil background reflectance while maintaining high sensitivity to a wide range of LAI.

Gonsamo, Alemu; Pellikka, Petri

2012-06-01

145

[Effects of different vegetation restoration patterns on the diversity of soil nitrogen-fixing microbes in Hulunbeier sandy land, Inner Mongolia of North China].  

Science.gov (United States)

By using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequence analysis, this paper studied the nifH gene diversity and community structure of soil nitrogen-fixing microbes in Hulunbeier sandy land of Inner Mongolia under four years management of five vegetation restoration modes, i. e., mixed-planting of Agropyron cristatum, Hedysarum fruticosum, Caragana korshinskii, and Elymus nutans (ACHE) and of Agropyron cristatum and Hedysarum fruticosum (AC), and mono-planting of Caragana korshinskii (UC), Agropyron cristatum (UA), and Hedysarum fruticosum (UH), taking the bare land as the control (CK). There existed significant differences in the community composition of nitrogen-fixing microbes among the five vegetation restoration patterns. The Shannon index of the nifH gene was the highest under ACHE, followed by under AC, UC, UA, and UH, and the lowest in CK. Except that UH and CK had less difference in the Shannon index, the other four vegetation restoration modes had a significantly higher Shannon index than CK (P < 0.05). The phylogenetic analysis showed that the soil nitrogen-fixing microbes under UA, UH, and UC were mainly of cyanobacteria, but the soil nitrogen-fixing microbes under AC and ACHE changed obviously, mainly of proteobacteria, and also of cyanobacteria. The canonical correlation analysis showed that the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen contents under the five vegetation restoration modes had significant effects on the nitrogen-fixing microbial communities, and there existed significant correlations among the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen. It was suggested that the variations of the community composition of soil nitrogen-fixing microbes under the five vegetation restoration modes were resulted from the interactive and combined effects of the soil physical and chemical factors. PMID:24066552

Li, Gang; Wang, Li-Juan; Li, Yu-Jie; Qiao, Jiang; Zhang, Hai-Fang; Song, Xiao-Long; Yang, Dian-Lin

2013-06-01

146

Comparison of the vegetation and seed bank on hedge banks of different ages in Brittany, France.  

Science.gov (United States)

The composition of the herbaceous cover and the seed bank of old and recent hedge banks in Brittany were studied and compared. Concentration method was used for seed bank samples. Grime's plant strategies were used to explain observed patterns. The analysis of the seed bank of these hedge banks showed that the species richness and diversity differed in relation to the date of construction of the hedge banks. The seed banks of recent hedge banks were richer and more diversified than those of old hedge banks. Differences in the floristic composition of the established plant cover between the recent and old hedge banks were determined by multivariate analyses. The species exclusively found in the seed bank and in the herb cover of recent hedge banks were mainly grassland species, whereas the species that only occurred on old hedge banks tended to be woodland species. The floristic composition of the two compartments (established vegetation and seed bank) was very different. A multivariate analysis revealed that the difference between the composition of the seed banks of recent and old hedge banks was less than that between the composition of the established vegetation and seed bank of hedge banks of the same age. Both seed bank and vegetation of recent hedge banks were dominated by ruderal species, whereas old hedge vegetation was dominated by stress-tolerant woodland species, indicating that mechanically constructed hedge banks may impose limitations on colonization by late woodland species. PMID:15383874

Pellissier, Vincent; Gallet, Sébastien; Rozé, Françoise

2004-07-01

147

The vegetation coverage dynamics due to geohazards after the 2008 earthquake in Wenchuan  

Science.gov (United States)

A catastrophic earthquake with a Richter magnitude of 8.0 occurred at Wenchuan area of Sichuan province on May 12, 2008. The earthquake destroyed forests and natural vegetation. As a result, it is necessary to assess the vegetation recovery rate for decision making and policy planning in earthquake region. In this paper, we calculated the vegetation index in 2001, 2009, 2010, 2013 employing RS methods. According to the analysis of mean change trend of vegetation index, the vegetation index in 2009 was clear lower than that in 2001, the main reason is that the vegetation loss caused by the 2008 Wenchuan earthquake; the vegetation index mean in 2010 was lower than that in 2009, and image imaging at different times, vegetation index mean reduction is caused by seasonal changes; the vegetation index mean in 2013 is slightly higher than that in 2010, it showed that vegetation coverage began to be slowly recovering after the earthquake. According to the standard deviation of vegetation index, vegetation index has the smallest standard deviation in 2001, this showed it has a good homogeneous distribution before the earthquake; vegetation index has the largest standard deviation in 2009, indicates poor homogeneity after the earthquake; from 2009 to 2010 and to 2013, the standard deviation of vegetation index becomes smaller year by year, means that the homogeneity becomes better and vegetation cover also slowly get better. We anticipate that these results will be helpful in decision making and policy planning for recovery and reconstruction in the earthquake-affected area.

Liu, Hanhu; Zeng, Sen; Xu, Jianming

2014-11-01

148

Phenology and growth of different vegetation types in the Ent Dynamic Global Terrestrial Ecosystem Model (DGTEM)  

Science.gov (United States)

The Ent Dynamic Global Terrestrial Ecosystem Model (DGTEM), is a new DGTEM for coupling the fluxes of water, energy, carbon and nitrogen between land surface and climate models, for simulating seasonal growth and decay of vegetation, and for simulating decadal- to century-scale vegetation cover change. This study shows the use of Fluxnet data in evaluating vegetation phenology, carbon allocation, and growth in the Ent DGTEM in both stand-alone mode and coupled mode to GISS Land Surface Model (LSM), and the performance of the coupled model at the global scale forced by Global Soil Wetness Project-2 (GSWP2) meteorology. Ecosystem types modeled include temperature broadleaf cold-deciduous forest at Harvard Forest, MA, and Morgan Monroe State Forest, IN; drought-senescent Mediterranean oak/annual grass savanna at Tonzi Ranch, CA, and annual grassland at Vaira Ranch, CA; and radiation phenology of tropical rainforest in Tapajos National Forest, Brazil. Site-level simulations forced with Fluxnet meterological data are evaluated by comparing the simulated leaf area index (LAI), carbon stocks in plant carbon pools, and carbon and water fluxes between land and the atmosphere against observational data. Global-scale simulations forced with GSWP2 data for 1986 to 1995 are performed to answer the question of whether the model, well-constrained against the local observations over the limited number of years, extrapolates well to global scales and captures interannual variation over the course of 10 years.

Kim, Y.; Moorcroft, P. R.; Koster, R. D.; Kiang, N. Y.

2009-12-01

149

Carbon and nitrogen in soil and vegetation at sites differing in successional age  

OpenAIRE

We studied vegetation and soil development during primary succession in an inland drift sand area in the Netherlands. We compared five sites at which primary succession had started at different moments in the past, respectively 0, 10, 43 and 121 years ago, and a site at which succession had not yet started. In the three younger sites the vegetation was herbaceous, whereas in the two older sites a pine forest had formed. Forest formation was accompanied by the development of an FH-layer in the...

Kovel, C. G. F.; Mierlo, A. J. E. M.; Wilms, Y. J. O.; Berendse, F.

2000-01-01

150

Different index contrast silica-on-silicon waveguides by PECVD  

DEFF Research Database (Denmark)

Ge-doped silica-on-silicon waveguides with index steps of 0.01 and 0.02 were fabricated by a combination of plasma enhanced chemical vapour deposition (PECVD) and reactive ion etching (RIE) techniques, and their characteristics, including propagation loss, coupling loss with standard singlemode fibres, minimal bend radius, and birefringence, were investigated. The waveguides have good propagation properties and small birefringence, compared to using flame hydrolysis deposition (FHD).

Ou, Haiyan

2003-01-01

151

Radiometric quality and performance of TIMESAT for smoothing moderate resolution imaging spectroradiometer enhanced vegetation index time series from western Bahia State, Brazil  

Science.gov (United States)

The launch of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra and Aqua platforms in 1999 and 2002, respectively, with temporal resolutions of 1 to 2 days opened the possibility of using a longtime series of satellite images to map land use and land cover classes from different regions of the Earth, to study vegetation phenology, and to monitor regional and global climate change, among other applications. The main objectives of this study were twofold: to analyze the radiometric quality of the time series of enhanced vegetation index (EVI) products derived from the Terra MODIS sensor in western Bahia State, Brazil, and to identify the most appropriate filter to smooth MODIS EVI time series of the study area among those available in the public domain, the TIMESAT algorithm. The 2000 to 2011 time period was considered (a total of 276 scenes). The radiometric quality was analyzed based on the pixel reliability data set available in the MOD13Q1 product. The performances of the three smoothing filters available within TIMESAT (double logistic, Savitzky-Golay, and asymmetric Gaussian) were analyzed using the Graybill's F test and Willmott statistics. Five percent of the MODIS pixels from the study area were cloud-affected, almost all of which were from the rainy season. The double logistic filter presented the best performance.

Borges, Elane F.; Sano, Edson E.; Medrado, Euzébio

2014-01-01

152

Effects of vegetation differences in relocated Utah prairie dog release sites  

Directory of Open Access Journals (Sweden)

Full Text Available Utah prairie dogs have been extirpated in 90% of their historical range. Because most of the population occurs on private land, this threatened species is continually in conflict with land-owners due to burrowing. The Utah Division of Wildlife Resources has been relocating Utah prairie dogs from private to public land since the 1970s, but relocations have been largely unsuccessful due to high mortality. Utah prairie dogs were relocated in 2010 and 2011 from the golf course in Cedar City, Utah to two prepared sites near Bryce Canyon National Park, Utah. Vegetation transects were established at each site to determine if there was a correlation between site vegetation composition and structure, and Utah prairie dog survival at relocation sites. The vegetation at the two sites was significantly different. One site had significantly less grass cover, more invasive plant cover, and rockier soils. The sites also had different soil structures and long-term Utah prairie dog retention rates. Newly established burrows were clustered rather than randomly distributed. Utah prairie dogs appeared to avoid placing burrows in areas with tall vegetation and rocky soils. More research is needed to determine how site selection determines longterm retention and colonization of a relocation site.

Rachel Curtis

2013-05-01

153

Soil phosphorus forms as quality indicators of soils under different vegetation covers.  

Science.gov (United States)

The type of vegetation cover determines the physicochemical and biological properties of the soil over which they are developing. The objective of this study was to determine the effect of different vegetation covers on the forms of soil phosphorus, in order to know which of these forms can be used as a soil quality indicator. The experimental area was located on the acidic plateau at the North of Palencia (North Spain), where an area was selected vegetation covers very close to each other: pine (Pinus sylvestris), oak (Quercus pyrenaica), and three different shrub species (Arctostaphylos uva-ursi, Erica australis and Halimium alyssoides). The Ah horizon was sampled and pH, total organic C (C(org)), total N (N), cationic exchange capacity (CEC), sum of bases (S) and P forms by a sequential fractionation were analysed. Results showed that oak and A. uva-ursi improve the considered soil parameters (pH, C(org)/N ratio, CEC, and S) and provide soils of better quality. Inorganic soil P forms were influenced in greater extent by the vegetation cover than were P organic forms. Labile inorganic P forms could be used as indicators of soil quality. The organic P forms were less sensitive than inorganic ones to the indicated improvements. PMID:17307240

Turrión, María-Belén; López, Olga; Lafuente, Francisco; Mulas, Rafael; Ruipérez, César; Puyo, Alberto

2007-05-25

154

Integrating vegetation index time series and meteorological data to understand the effect of the land use/land cover (LULC) in the climatic seasonality of the Brazilian Cerrado  

Science.gov (United States)

The Cerrado (savanna ecosystem) of São Paulo state (Brazil) represent a complex mosaic of different typologies of uses, actors and biophysical and social restrictions. Originally, 14% of the state of São Paulo area was covered by the diversity of Cerrado phytophysiognomies. Currently, only 1% of this original composition remains fragmented into numerous relicts of biodiversity, mainly concentrated in the central-eastern of the state. A relevant part of the fragments are found in areas of intense coverage change by human activities, whereas the greatest pressure comes from sugar cane cultivation, either by direct replacement of Cerrado vegetation or occupying pasture areas in the fragments edges. As a result, new local level dynamics has been introduced, directly or indirectly, affecting the established of processes in climate systems. In this study, the main goal is analyzing the relationship between the Cerrado landscape changing and the climate dynamics in regional and local areas. The multi-temporal MODIS 250 m Vegetation Index (VI) datasets (period of 2000 to 2012) are integrated with precipitation data of the correspondent period (http://www.agritempo.gov.br/),one of the most important variable of the spatial phytophysiognomies distribution. The integration of meteorological data enable the development of an integrated approach to understand the relationship between climatic seasonality and the changes in the spatial patterns. A procedure to congregated diverse dynamics information is the Self Organizing Map (SOM, Kohonen, 2001), a technique that relies on unsupervised competitive learning (Kohonen and Somervuo 2002) to recognize patterns. In this approach, high-dimensional data are represented on two dimensions, making possible to obtain patterns that takes into account information from different natures. Observed advances will contribute to bring machine-learning techniques as a valid tool to provide improve in land use/land cover (LULC) analyzes at different hierarchical scales to support numerous science and policy applications.

Lins, D. B.; Zullo, J.; Friedel, M. J.

2013-12-01

155

Diversity of Halophyte Desert Vegetation of the Different Saline Habitats in the Valley of Oued Righ, Low Sahara Basin, Algeria  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the present study was to investigate the floristic composition and diversity of the different habitat types in the saline areas of the valley of Oued Righ, locating in the low Sahara basin of Algeria. Three distinct saline habitats were examined: saline soil habitats, subsaline soil habitats, and waterlogged habitats. A total of 67 stands along the study area were investigated using the quadrat method, and different vegetation parameters, such as cover, frequency, density, and Importance Value Index (IVI, were recorded. Differences of species diversity and richness between saline habitats were also compared. A total of 38 plant species belonging to 29 genera and 13 families were identified from the three studied habitats. Chenopodiaceae was the predominant family. The majority of the species were of Saharo-Arabian distribution. Chemaephytes had the highest contribution to the life forms spectra. Species composition in the different habitat types showed differences in species richness. Subsaline soil habitats were the most diverse, followed by saline soil habitats. Waterlogged habitats had the lowest diversity. The floristic composition and the dominant species of each habitat were presented. The potential role of the halophyte species was discussed. These findings may lead to a better understanding of the functions, requirements, and sensitivities of these ecosystems.

Belhamra Mohamed

2012-03-01

156

The effects of different salt, biostimulant and temperature levels on seed germination of some vegetable species  

Directory of Open Access Journals (Sweden)

Full Text Available This research was conducted to determine the effects of two biostimulants (humic acid and biozyme or three different salt (NaCl concentrations at the temperature 10, 15, 20 and 25°C on parsley, leek, celery, tomato, onion, lettuce, basil, radish and garden cress seed germination. Two applications of both biostimulants increased seed germination of parsley, celery and leek at all temperature treatments. Germination rate decreased depending on high salt concentrations. At different salt and temperature levels garden cress was characterised by the highest germination percentage compared to other vegetable species.Interactions between NaCl concentrations and temperatures, as welI as biostimulants and temperatures were significant at p=0.001 in for all vegetable species except onion in NaCl concentrations and temperatures compared to that of the control.

Ertan Yildirim

2002-12-01

157

Interannual variations and trends in global land surface phenology derived from enhanced vegetation index during 1982-2010  

Science.gov (United States)

Land surface phenology is widely retrieved from satellite observations at regional and global scales, and its long-term record has been demonstrated to be a valuable tool for reconstructing past climate variations, monitoring the dynamics of terrestrial ecosystems in response to climate impacts, and predicting biological responses to future climate scenarios. This study detected global land surface phenology from the advanced very high resolution radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) data from 1982 to 2010. Based on daily enhanced vegetation index at a spatial resolution of 0.05 degrees, we simulated the seasonal vegetative trajectory for each individual pixel using piecewise logistic models, which was then used to detect the onset of greenness increase (OGI) and the length of vegetation growing season (GSL). Further, both overall interannual variations and pixel-based trends were examined across Koeppen's climate regions for the periods of 1982-1999 and 2000-2010, respectively. The results show that OGI and GSL varied considerably during 1982-2010 across the globe. Generally, the interannual variation could be more than a month in precipitation-controlled tropical and dry climates while it was mainly less than 15 days in temperature-controlled temperate, cold, and polar climates. OGI, overall, shifted early, and GSL was prolonged from 1982 to 2010 in most climate regions in North America and Asia while the consistently significant trends only occurred in cold climate and polar climate in North America. The overall trends in Europe were generally insignificant. Over South America, late OGI was consistent (particularly from 1982 to 1999) while either positive or negative GSL trends in a climate region were mostly reversed between the periods of 1982-1999 and 2000-2010. In the Northern Hemisphere of Africa, OGI trends were mostly insignificant, but prolonged GSL was evident over individual climate regions during the last 3 decades. OGI mainly showed late trends in the Southern Hemisphere of Africa while GSL was reversed from reduced GSL trends (1982-1999) to prolonged trends (2000-2010). In Australia, GSL exhibited considerable interannual variation, but the consistent trend lacked presence in most regions. Finally, the proportion of pixels with significant trends was less than 1 % in most of climate regions although it could be as large as 10 %.

Zhang, Xiaoyang; Tan, Bin; Yu, Yunyue

2014-05-01

158

Natural extracts from Pterospartum tridentatum at different vegetative stages: extraction yiels, phenolic content and antioxidant activity  

OpenAIRE

The aerial parts of Pterospartum tridentatum, a wild growing species in Portugal used in traditional medicine and gastronomy, were harvested at different stages (vegetative phase, flowering phase and beginning of dormancy) in two locations in Portugal (Malcata and Gardunha mountains), and the respective aqueous extracts have been studied. The influence of the seasonal variation in the extraction yield, total phenolic content and antioxidant activity was evaluated. The extraction w...

Coelho, M. T.; Pimenta, C.; Gonc?alves, J. C.; Alves, V.; Martins, M. M.

2012-01-01

159

Constructed wetland systems vegetated with different plants applied to the treatment of tannery wastewater  

OpenAIRE

Wastewaters from leather processing are very complex and lead to water pollution if discharged untreated, especially due to its high organic loading. In this study the survival of different plant species in subsurface horizontal flow constructed wetlands receiving tannery wastewater was investigated. Five pilot units were vegetated with Canna indica, Typha latifolia, Phragmites australis, Stenotaphrum secundatum and Iris pseudacorus, and a sixth unit was left as an unvegetated control. The...

Calheiros, Cristina S. C.; Rangel, Anto?nio O. S. S.; Castro, Paula M. L.

2007-01-01

160

Leaf area index estimation in different crops: Case study for wheat, maize, soybean, and potato  

Science.gov (United States)

Vegetation indices (VIs) have been shown to be a proxy of green leaf area index (gLAI); however, it has not been verified whether the relationships VI vs. gLAI are the same, as well as VIs retaining their accuracy, for various crop types for estimating gLAI. The goal of this study was to (1) determine if the best VIs used in previous studies for gLAI estimation in maize and soybean may be applicable for potato and wheat and vice versa, and (2) determining the cause of a hysteresis between green up and reproductive stages for the VI vs. gLAI relationship. Spectral measurements of wheat and potato were obtained in Israel and of maize and soybean in the USA. In Israel, remote estimates of gLAI were compared with in-situ canopy transmittance measurements of irrigated potato and wheat under various nitrogen treatments from 2004-2007 for a total of 15 field-years. In eastern Nebraska, USA, remote estimates of maize and soybean gLAI data were compared with destructive gLAI determination in two irrigated/rainfed maize/soybean rotation sites and in one irrigated site under continuous maize. These data were collected during eight years (2001-2008) for a total of 24 field-years. For all four crops, the ten VIs examined showed similarities in relationships between VIs and gLAI with the exception of Red-edge Inflection Point (REIP) and the MERIS Terrestrial Chlorophyll Index (MTCI). REIP and MTCI have very different relationships with maize and soybean gLAI in green up and reproductive stages, thus, they require re-parameterization during the season. This study outlines the two major factors that influence the VI vs. gLAI relationship in the green up and reproductive stages. While the results suggest that relationships VI vs. gLAI are quite close for all four crops, different methodologies in determining the ground-truth measurements of gLAI prevent us to confirm whether algorithms calibrated for one crop can be used with no re-parameterization for other crops. These concerns aside, we found that normalized difference VIs (NDVI, Green NDVI, etc.) were capable of estimating accurately gLAI below 2 and ratio VIs (Simple Ratio, CIgreen, etc.) were best for gLAI above 2. For all four crops, green and red-edge chlorophyll indices appear to be the most accurate for gLAI estimation.

Gitelson, A. A.; Nguy-Robertson, A. L.; Peng, Y.; Arkebauer, T. J.; Pimstein, A.; Herrmann, I.; Karnieli, A.; Rundquist, D. C.; Bonfil, D.

2012-12-01

161

Estimating evapotranspiration using remote sensing: A hybrid approach between MODIS derived enhanced vegetation index, Bowen ratio system, and ground based micro-meteorological data  

Science.gov (United States)

We investigated water loss by evapotranspiration (ET) from the Palo Verde Irrigation District (PVID) and the Cibola National Wildlife Refuge (CNWR) in southern California bordering the Colorado River collaborating with the United States Bureau of Reclamation (U.S.B.R.). We developed an empirical model to estimate ET for the entire PVID using satellite derived MODIS enhanced vegetation index (EVI), and ground based measurements of solar radiation and vapor pressure. We compared our predictions with U.S.B.R. estimates through statistical cross validation and showed they agree with an error less than 8%. We tested the same model for an alfalfa field inside PVID to check its applicability at a smaller spatial scale. We showed that the same model developed for PVID is the best model for estimating ET for the alfalfa field. We collected data from three Bowen ratio energy balance (BREB) towers installed in the invasive saltcedar (Tamarix spp) dominated riparian zone in the CNWR and a fourth tower in the alfalfa field in PVID. The riparian sites were selected according to different densities of vegetation. We collected data from these sites at various intervals during the period between June 2006 to November 2008. We reduced the errors associated with the Bowen ratio data using statistical procedures taking into account occasional instrument failures and problems inherent in the BREB method. Our results were consistent with vegetation density and estimates from MODIS EVI images. To estimate ET for larger patches of mixed vegetation we modified the crop coefficient equation and represented it in terms of EVI. Using this approach, we scaled the alfalfa field data to the entire PVID and compared the results with U.S.B.R. (2001-2007) estimates. We predicted ET well within the acceptable range established in the literature. We empirically developed ET models for the riparian tower sites to provide accurate point scale ET estimation and scaled for the entire riparian region in CNWR with our modified crop coefficient approach. We investigated the assumptions upon which the Bowen ratio equation is developed. In the presence of turbulence some of the assumptions may not be valid, and the final data may require correction factors.

Chatterjee, Sumantra

162

Morphological changes and vegetation index variation along the western coastal zone of Bangladesh  

OpenAIRE

Being a low laying deltaic country, morphological changes along the Bangladesh coastal zones are of major socio-economic and environmental concern. In this study, images of LANDSAT captured during 1989-2010 are analyzed to detect the variation of shoreline positions. Western coast has been divided into different segments and the rates of change of shoreline positions have been analyzed over three time periods 1989-2000, 2000-2006 and 2006-2010. AVHRR GIMMS and MODIS NDVI (Normalized Differenc...

Shibly, A. Md; Takekawa, S.

2013-01-01

163

The Effectiveness of Web Search Engines to Index New Sites from Different Countries  

Science.gov (United States)

Introduction: Investigates how effectively Web search engines index new sites from different countries. The primary interest is whether new sites are indexed equally or whether search engines are biased towards certain countries. If major search engines show biased coverage it can be considered a significant economic and political problem because…

Pirkola, Ari

2009-01-01

164

Vegetation differences and diagenetic changes between two Bulgarian lignite deposits - Insights from coal petrology and biomarker composition  

Energy Technology Data Exchange (ETDEWEB)

In this study, we review the petrographic composition and biomarker assemblage of two adjacent basins in western Bulgaria, i.e. Beli Breg and Staniantsi basins. Both contain lignite formed during late Miocene (c. 6 Ma). Despite similar tectonic settings and depositional environments, the lignite seams possess different petrographic and organic geochemical characteristics, reflecting differences in the peat forming palaeo-communities and fades variations. The peat-forming vegetation in Bell Breg Basin was dominated by decay resistant coniferous plants, as indicated by abundant fossil wood remains, very good tissue preservation and a biomarker assemblage dominated by diterpenoids. In contrast, Staniantsi lignite is poor in fossil wood and contains a significant amount of triterpenoid biomarkers, suggesting the predominance of angiosperm plants in the swamp. The results of the biomarker analyses are consistent with palaeobotanical and palynological data from the literature. The lignite seams in both basins formed under frequently changing Eh conditions, as indicated by the severe degradation of the non-gymnosperm tissues, the low gelification index values and the variations in pristane/phytane ratio, probably as a result of seasonal drying of the swamps and changes of the ground water table. Hopanoid contents in Bell Breg lignite are very low and are consistent with the abundance of decay-resistant vegetation. In contrast, bacterial activity was obviously higher in the Staniantsi swamp, however, resulting only in slightly enhanced gelification of plant tissues. The geochemical data suggest that the diagenetic changes of the organic matter were mainly governed by thermal degradation, rather than bacterial activity.

Zdravkov, A.; Bechtel, A.; Sachsenhofer, R.F.; Kortenski, J.; Gratzer, R. [University of Mining & Geology St Ivan Rilski, Sofia (Bulgaria)

2011-03-15

165

Comparative study of trace element levels in some local vegetable varieties and irrigation waters from different locations in Ilorin, Nigeria  

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Full Text Available The level of heavy metals in two varieties of vegetables harvested during the dry and wet seasons from seven different locations in Ilorin, Nigeria, were determined. The correlation between the level of metals in the vegetables and the irrigation water was also studied. Vegetables harvested during the dry season were found to contain higher level of toxic metals. Low water quality, accumulation of particulate after rainless period and nearness of some vegetable gardens to major and well travelled roads appeared to be the major contributory factors. Amaranthus hybridus seemed to have higher metal accumulation capacity compared to Corchorus olitorius mannii.

O.O. Dosumu

2003-06-01

166

Manufacture of Cheese from Skim Milk with Addition of Different Levels of Vegetable Oil  

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Full Text Available The experiment was conducted to manufacture cheese from skim milk with 30, 40 and 50 g kg-1 soybean oil and whole milk and to monitor the quality of different types of prepared cheese. It was observed that the flavour, taste, colour and appearance, body and texture, overall acceptability and final score were significantly higher in whole milk cheese than that of other types of vegetable oil based (30, 40 and 50 g kg-1 skim milk cheese. Chemical analysis showed that there were significant differences (P<0.01 incase of protein and fat contents of different types of cheeses. On the other hand there were no significant differences in moisture, total solids, ash and acidity content of different types of cheese. Although some chemical parameters showed that the quality of soybean oil based (30, 40 and 50 g kg-1 skim milk cheeses were better than the whole milk cheese but expert judges gave their opinion in favour of whole milk cheese, on the basis of organoleptic evaluation. It may be concluded that cheese could be manufactured successfully from skim milk with 30, 40 and 50 g kg-1 soyabean oil and it will open a new door in business sector and experiment also could solve the protein deficiency of Bangladesh. According to panelists score 50 g vegetable oil based skim milk cheese was better than other types of skim milk cheese.

A. Ara

2002-01-01

167

Analysis of Vegetation Behavior in a North African Semi-Arid Region, Using SPOT-VEGETATION NDVI Data  

OpenAIRE

The analysis of vegetation dynamics is essential in semi-arid regions, in particular because of the frequent occurrence of long periods of drought. In this paper, multi-temporal series of the Normalized Difference of Vegetation Index (NDVI), derived from SPOT-VEGETATION satellite data between September 1998 and June 2010, were used to analyze the vegetation dynamics over the semi-arid central region of Tunisia. A study of the persistence of three types of vegetation (pastures, annual agricult...

Abdelghani Chehbouni; Claire Gruhier; Zohra Lili-Chabaane; Mehrez Zribi; Rim Amri; Benoit Duchemin

2011-01-01

168

Radium and uranium levels in vegetables grown using different farming management systems  

International Nuclear Information System (INIS)

Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of 238U, 226Ra and 228Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for 226Ra, 0.55 for 228Ra and 0.24 for 238U (Bq kg-1 dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10-4 to 10-2 for 238U and from 10-2 to 10-1 for 228Ra

169

A Preliminary Study on Genetic Variation of Arsenic Concentration in 32 Different Genotypes of Leafy Vegetable  

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Full Text Available Leafy vegetables are a food crop with higher protein and are also important source of minerals which are essential for good health. Due to the large consumption, it is necessary to decrease the arsenic (As concentration in leafy vegetable to avoid the potential risk to human health. The current study is aimed at assessing arsenic (As accumulation ability and identification of cultivars with less As concentration that could be grown in As contaminated farmland for food safety. A set of thirty two leafy vegetable cultivars from 5 species were compared in hydroponics for 2 weeks having moderate level of 0- control and 6 mg As L-1. At harvest, plants were sampled and analyzed for As concentration. Significant genotypic variations were observed in the shoots As concentration, translocation and bioaccumulation factors revealing more than 8 and 25 times cultivar differences in shoot As concentration, and in translocation factors respectively. This result revealed that As concentration in shoot was in part governed by the greater ability of root-shoot translocation. Cultivar Sijibaiye (SJBY had the lowest shoot As concentration while the highest was detected in Dayekongxincai (DYKXC. The average As concentration in roots were found to be ten to twenty times higher than those observed in shoots, indicating that there is restricted transport of As from the root system to the shoot of cultivars. Therefore, it has been suggested that there is possibility to lower the As concentration in leafy vegetables by selecting and breeding cultivars with less As concentration that can be safely grown in contaminated soils with the slight and moderate levels of As for safe consumption.

Mathieu Nsenga Kumwimba

2014-04-01

170

Resting-state EEG study of comatose patients: a connectivity and frequency analysis to find differences between vegetative and minimally conscious states.  

OpenAIRE

The aim of this study was to look for differences in the power spectra and in EEG connectivity measures between patients in the vegetative state (VS/UWS) and patients in the minimally conscious state (MCS). The EEG of 31 patients was recorded and analyzed. Power spectra were obtained using modern multitaper methods. Three connectivity measures (coherence, the imaginary part of coherency and the phase lag index) were computed. Of the 31 patients, 21 were diagnosed as MCS and 10 as VS/UWS using...

Lehembre, Remy; Bruno, Marie-aure?lie; Vanhaudenhuyse, Audrey; Chatelle, Camille; Cologan, Victor; Leclercq, Yves; Soddu, Andrea; Macq, Benoit; Laureys, Steven; Noirhomme, Quentin

2012-01-01

171

Environmental quality evaluation. Indexing tools to evaluate environmental quality from biological data, floristic and vegetational data in Ponte Galeria (Rome, Italy)  

International Nuclear Information System (INIS)

In the present work the study of indexing tools to evaluate environmental quality from biological data has been performed using a certain number of floristic and vegetational indices near Macchia Grande of Ponte Galeria (Rome, Italy). The indices have been applied on the basis of the data coming from a phyto sociological study of the area. Multivariate statistics methodologies have been utilized to obtain a synthetic evaluation of the indices

172

[Soil physical and chemical characteristics under different vegetation restoration patterns in China south subtropical area].  

Science.gov (United States)

This paper studied the change of soil physical and chemical properties under eleven vegetation restoration patterns (1 kind of secondary forest, 2 kinds of pure coniferous plantations, 5 kinds of evergreen broad-leaved plantations, 2 kinds of conifer and broad-leaved mixed plantations, and 1 kind of shrub) typical in Daqingshan of Guangxi. Obvious differences were observed in the soil physical and chemical properties under different vegetation restoration patterns. The soil physical properties were better in secondary forest but poorer in pure conifer plantations. Conifer and broad-leaved mixed plantations had lower soil bulk density, and their soil total porosity and water-holding capacity were higher than those in pure plantations. There were no significant differences in the soil porosity among the 5 evergreen broad-leaved plantations. Except that of soil total K, the contents of soil nutrients in secondary forest were higher than those in plantations, and the soil C/N ratio and pH value were relatively lower. Comparing with shrub, the 9 plantations had an obvious change in their soil nutrient contents, e. g. , the increase of soil total N and available K. The 2 pure coniferous plantations had lower soil nutrient contents, but after mixed planted with evergreen broad-leaved trees, their soil nutrient contents increased markedly, and the soil C/N ratio decreased. PMID:21328932

Kang, Bing; Liu, Shi-rong; Cai, Dao-xiong; Lu, Li-hua; He, Ri-ming; Gao, Yan-xia; Di, Wei-zhi

2010-10-01

173

Estimating vegetation dryness to optimize fire risk assessment with spot vegetation satellite data in savanna ecosystems  

Science.gov (United States)

The lack of information on vegetation dryness prior to the use of fire as a management tool often leads to a significant deterioration of the savanna ecosystem. This paper therefore evaluated the capacity of SPOT VEGETATION time-series to monitor the vegetation dryness (i.e., vegetation moisture content per vegetation amount) in order to optimize fire risk assessment in the savanna ecosystem of Kruger National Park in South Africa. The integrated Relative Vegetation Index approach (iRVI) to quantify the amount of herbaceous biomass at the end of the rain season and the Accumulated Relative Normalized Difference vegetation index decrement (ARND) related to vegetation moisture content were selected. The iRVI and ARND related to vegetation amount and moisture content, respectively, were combined in order to monitor vegetation dryness and optimize fire risk assessment in the savanna ecosystems. In situ fire activity data was used to evaluate the significance of the iRVI and ARND to monitor vegetation dryness for fire risk assessment. Results from the binary logistic regression analysis confirmed that the assessment of fire risk was optimized by integration of both the vegetation quantity (iRVI) and vegetation moisture content (ARND) as statistically significant explanatory variables. Consequently, the integrated use of both iRVI and ARND to monitor vegetation dryness provides a more suitable tool for fire management and suppression compared to other traditional satellite-based fire risk assessment methods, only related to vegetation moisture content.

Verbesselt, J.; Somers, B.; Lhermitte, S.; van Aardt, J.; Jonckheere, I.; Coppin, P.

2005-10-01

174

The relationship of hyper-spectral vegetation indices with leaf area index (LAI) over the growth cycle of wheat and chickpea at 3 nm spectral resolution  

Science.gov (United States)

Hyperspectral ratio and normalized difference vegetation indices were computed from the 3 nm bandwidth ground-based spectral data taken in 400-950 nm wave length region over the crop growth cycle (CGC) of wheat and chickpea. Synthesized broad band Landsat TM-RVI, TM-NDVI and TM-SAVI were also computed using this narrow bandwidth spectral observations. Regression analysis was carried out for these indices with leaf area index (LAI) for wheat and chickpea over CGC and the r2 values were found poor in 0.2-0.53 range for wheat and in 0.41-0.82 range for chickpea. Significant relationship with LAI were found for wheat ( r2 in 0.86-0.97 range) when growth and decline phases were analyzed independently. Here, r2 values for chickpea were less than that for wheat. The high difference in rate of change of slope for hRVI is a good discriminator for high ET (wheat) and low ET (chickpea) crops. To find out the potential hyperspectral ratios and normalized difference indices that could provide strong relationship with LAI, a correlation-based analysis was carried out for LAI with all the possible combinations of ratios and normalized difference indices in 400-950 nm region (at 3 nm spectral interval) independently for growth and decline phases of LAI and found that in addition to traditional near-IR and red pairs, the pairs within near-IR, near-IR and visible extending to near-IR were also significantly related to LAI.

Gupta, R. K.; Vijayan, D.; Prasad, T. S.

2006-01-01

175

Woody and grassy vegetation development in different landscape elements of the Curonian spit  

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Full Text Available The species of woody and grassy establish on seashore sands and wastes. These plants are adapted for less favorable existence conditions some of them growing in littoral habitats of excessive moisture and salinity. Other tolerates infertile and dry sand. The purpose of the study have been analyzed the dispersion vegetation in different relief elements of the coastal protective dune look for a relation between woody and grassy plant species to foresee the tendencies of further seashore landscape development. It has been established that in locations with intensive flow of visitors a net of trodden paths is formed where the plants cover is disappearing very fast as there are suitable conditions for the springtime and autumn winds to erode the coastal protective dune of the seashore of the Curonian spit. The trodden path in a couple of years turn into 2 – 3 m. vides sand drifting corridors, but the lies of the holiday makers become there 4 – 5 m. wide pit and hollow. After these formations have interconnected they shape deflations of different size. The drifting sand carried by the prevailing western direction winds swamp the beyond coastal dune plains and the outskirts of the forest and sandy meadows. The statistical analysis of projection cover of plant shows that during the last 27 years (from 1982 the conditions for vegetation survival on the Curonian spit seashore sand dunes are gradually deteriorating.

Algimantas Me?islovas Olšausaks

2009-12-01

176

Performance Test of CI Engine with Different Vegetable Oil as a Fuel  

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Full Text Available Today, the diesel engine is still capable of running on “biodiesel” fuel, which can be produced from a variety of renewable sources, including soyabean oil, canola oil, sunflower oil, cottonseed oil, and animal fats. These sources can be obtained from agricultural feedstocks or by recycling used oil such as cooking grease. Biodiesel is usable in it’s pure form known as “neat biodiesel” or B100. In addition, it is available in various blends with petrodiesel, the most common of which is known as B20(20 percent biodiesel and 80 percent petrodiesel.it is also used in smaller percentage as a lubricating fuel additives.Copious resource of vegetable oil in India and its ease of translation to biodiesel help to save large expenses done on import of petroleum products and monetary growth of country. Biodiesel also generates enormous rural employment and degraded lands can be restored due to plantation of oil plants which help in reducing greenhouse gasses. in this paper we discuss & compare different performance parameters of C.I. engine with different vegetable oil as a fuel

Mr.Paresh K. Kasundra ¹ *, Prof. Ashish V. Gohil²

2011-12-01

177

Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure  

Science.gov (United States)

We examined sexual differences in patterns of vegetation structure selection in the sexually dimorphic little bustard. Differences in vegetation structure between male, female and non-used locations during reproduction were examined and used to build a presence/absence model for each sex. Ten variables were measured in each location, extracting two PCA factors (PC1: a visibility-shelter gradient; PC2: a gradient in food availability) used as response variables in GLM explanatory models. Both factors significantly differed between female, male and control locations. Neither study site nor phenology was significant. Logistic regression was used to model male and female presence/absence. Female presence was positively associated to cover of ground by vegetation litter, as well as overall vegetation cover, and negatively to vegetation density over 30 cm above ground. Male presence was positively related to litter cover and short vegetation and negatively to vegetation density over 30 cm above ground. Models showed good global performance and robustness. Female microhabitat selection and distribution seems to be related to the balance between shelter and visibility for surveillance. Male microhabitat selection would be related mainly to the need of conspicuousness for courtship. Accessibility to food resources seems to be equally important for both sexes. Differences suggest ecological sexual segregation resulting from different ecological constraints. These are the first detailed results on vegetation structure selection in both male and female little bustards, and are useful in designing management measures addressing vegetation structure irrespective of landscape composition. Similar microhabitat approaches can be applied to manage the habitat of many declining farmland birds.

Morales, M. B.; Traba, J.; Carriles, E.; Delgado, M. P.; de la Morena, E. L. García

2008-11-01

178

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index  

OpenAIRE

Abstract Background Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI). Methods and Results In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first de...

Moreira Leila B.; Fuchs Flávio D.; Fuchs Sandra C.; Wittke Estefânia; Ferlin Elton; Cichelero Fábio T; Moreira Carolina M; Neyeloff Jeruza; Moreira Marina B; Gus Miguel

2010-01-01

179

Diseño de un índice espectral de la vegetación desde una perspectiva conjunta de los patrones exponenciales y lineales del crecimiento / Design of a spectral vegetation index under the joint perspective of exponential and linear growth patterns  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish En este trabajo se analizan diferentes experimentos con mediciones de reflectancia para revisar los patrones de las primeras dos constantes de los modelos de interacciones radiativas en el espacio del rojo (R) e infrarrojo cercano (IRC), concluyéndose de la evidencia experimental que el modelo de in [...] teracciones de orden uno es suficiente para este fin. En segundo lugar se desarrolla el algoritmo del índice espectral IV_CIMAS y se aplica a experimentos de cultivos, concluyéndose que este índice sólo tiene una relativa mejoría en relación con el índice NDVIcp, y que ambos describen bien la fase expo-lineal de la etapa vegetativa de la vegetación. La fase reproductiva no es modelada en forma adecuada por ninguno de los índices espectrales. Finalmente, se revisan los modelos de la geometría sol-sensor propuestos, y se concluye que éstos tienen buenos ajustes experimentales, permitiendo estandarizar esta geometría. La modelación de los patrones asociados a las constantes de las curvas espectrales de igual vegetación es muy difícil de realizar por las propiedades de los espacios usados. El problema del diseño de índices de vegetación es todavía un problema abierto. Abstract in english This study analyzes different experiments with reflectance measurements to review the patterns of the first two constants of the models of radiative interaction in the red (R) and near infrared (NIR) space. From experimental evidence, it is concluded that the first order model of interactions is suf [...] ficient for this aim. Secondly, the algorithm of the spectral index IV_CIMAS is developed and applied to crop experiments, concluding that this index is only a relative improvement over the NDVIcp index and that the expo-linear phase of the vegetative growth stage of the vegetation are well-described by both. The reproductive phase is not adequately modeled by either of the spectral indexes. Finally, the models of sun-sensor geometry proposed are reviewed, and it is concluded that these have good experimental fit, allowing this geometry to be standardized. Modeling of the associated patterns to the spectral curve constants of equal vegetation is very difficult to do because of properties of the spaces used. The problem of designing vegetation indexes is still open.

Enrique, Romero-Sánchez; Fernando, Paz-Pellat; Enrique, Palacios-Vélez; Martín, Bolaños-González; René, Valdez-Lazalde; Arnulfo, Aldrete.

2009-05-01

180

Profitability and morphological characters of inter-cropping of different vegetables in tea  

International Nuclear Information System (INIS)

A field experiment was conducted at National Tea Research Institute, Shinkiari, Mansehra, during 2006-07 to find out the most productive and profitable tea-based intercropping system with different vegetable crops. The vegetables included were brinjal solanum melongena , chilies Capsicum annum, okra Ahle moselous, potato Solanum tuberosum, spinach Spinacia oleracea, garlic Allium sativum, onion Allium cepa, peas Pisum sativum and tomato Lycopersicon esculentum, as intercrop combination in newly planted tea. Intercropping of peas showed up poorest among all other treatments, in net income of Rs. 4,800.0, whereas intercrops significantly affected no. of branches, leaves, fresh and dry weight/plant of tea crop respectively. Considering the net return and total expenditure incurred on raising of intercrops, the highest net profit of Rs. 6,669.0/acre was obtained from potato, followed by garlic at Rs. 6,200.0. All treatments combination is more or less similar in net return, except T/sub 5/. Yield and yield-attributes in all treatments were significantly affected. Whereas branches and fresh weight remained significant among each other except sole tea crop. Agronomic data showed that the cropping days were also varies from 45 to 150 days in all treatments. Therefore it might be more economically viable than sole tea crop, upto complete bush formation. (author)

181

The vegetative development of Sinningia leucotricha Hoehne (Moore under different levels of shading  

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Full Text Available This work aimed at the assessment of the influence of different levels of shading in the development of (Sinningia leucotricha Hoehne (Moore. Tuberous roots of 2.3 ± 0.3 cm in diameter were used as vegetative material. The cultivation was performed in plastic vases and gross sand as substrate, and conditioned in sheltered nurseries protected by black polypropylene nets in the followings percentages: 0% (under full sunlight, 50, 60, and 70%. Sheltered nurseries with 60 or 70% of shading presented the highest vegetative development for Brazilian edelweiss. The cultivation of this species under full sunlight is not recommended.A rainha-do-abismo (Sinningia leucotricha Hoehne (Moore é uma planta nativa do Estado do Paraná, se destaca pela beleza de suas folhas de aspecto prateado. Este trabalho teve como objetivo avaliar a influência de diferentes níveis de sombreamento no desenvolvimento de plantas de rainha-do-abismo. Para o experimento foram utilizadas como material vegetativo raízes tuberosas com 2,3 ± 0,3 cm de diâmetro. O cultivo foi realizado em vasos plásticos e areia grossa como substrato, que foram acondicionados em viveiros protegidos com tela de polipropileno de coloração preta, nas seguintes porcentagens: 0% (a pleno sol 50%, 60% e 70%. Viveiros protegidos com 60% ou 70% de sombreamento foram os que proporcionaram maior desenvolvimento vegetativo de rainha-do-abismo. O cultivo desta espécie a pleno sol não é recomendado.

Lilian Keiko Unemoto

2010-02-01

182

[Characteristics of soil microelements contents in the rhizospheres of different vegetation in hilly-gully region of Loess Plateau].  

Science.gov (United States)

To explore the rhizosphere effect of the microelements in the soils under different vegetation types in Loess Plateau, this paper analyzed the organic C, total N, Mn, Cu, Fe, and Zn contents in the rhizosphere soil and bulk soil of six vegetation types in hilly-gully region of Loess Plateau. Among the six vegetation types, Caragana korshinskii, Heteropappus altaicus, and Artemisia capillaries had higher organic C and total N contents in rhizosphere soil than in bulk soil. With the exception of C. korshinskii and H. rhamnoides, all the six vegetation types had a significantly lower pH in rhizosphere soil than in bulk soil. The six vegetation types had a lower available Mn content in rhizosphere soil than in bulk soil, and the C. korshinskii, Astragalus adsurgen, and Panicum virgatum had a significantly higher available Cu content in rhizosphere soil than in bulk soil. The six vegetation types except A. adsurgens had a slightly higher available Fe content in rhizosphere soil than in bulk soil, and A. adsurgens, P. virgatum, H. altaicus, and A. capillaries had a significant accumulation of available Zn in rhizosphere soil. There existed significant positive correlations between the rhizosphere soil and bulk soil of the six vegetation types in the relationships between the organic C and total N contents and the available Mn and Zn contents and between the contents of available Mn and Zn. In rhizosphere soil, available Mn and Zn contents were significantly negative- ly correlated with pH value. Due to the differences in root growth characteristics, rhizosphere pH value, and microbial structure composition, the microelements contents in the rhizosphere soil of the six vegetation types differed, with the contents of Mn, Cu, Fe, and Zn being higher in the rhizosphere soil of H. altaicus than in that of the other vegetation types. PMID:22720606

Zhang, Chao; Liu, Guo-Bin; Xue, Sha; Zhang, Chang-Sheng

2012-03-01

183

The role of vegetated areas on fish assemblage of the Paraná River floodplain: effects of different hydrological conditions  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we analyze the changes in composition and abundance of fish assemblages in seven vegetated floodplain wetlands with different connectivity across different hydrologic conditions: after a prolonged connection of the floodplain with the main channel, during receding water, and after a prolonged isolation. We also investigated the size and abundance of large-sized migratory species found in these wetlands and the food resources exploited by the dominant fish. Fishes were captured by diurnal seining (8.0 m x 1.50 m, 5 mm mesh along macrophyte banks. Despite the high total number of species registered (100, sample species richness varied between 7 and 31, depending on the sampling site and the sampling date. Cluster analysis indicated low similarity between sites during both the isolation and the prolonged connection. Species turnover decreased from high water (? = 40.33 to low water (? = 33.83, with the minimum value of beta diversity index obtained during the isolation of the floodplain wetlands (? = 26.83. Our results indicated that different dominant populations of fish occur in different hydrological conditions, even though high water and isolation phases occur in the same season of different years. The ordination (NMDS indicated the importance of hydrologic conditions in structuring fish assemblages in the studied floodplain. Small-sized characids, typically associated with macrophytes, dominated the fish assemblages, whereas the younger stages of large sized migratory species were found in low abundance. The maximum standard length of the fish captured was 28 cm and for large migratory fish, standard length varied between 1.6 and 25.0 cm. The dominant fish used several food resources, but littoral macrophytes-associated organisms had a high frequency of occurrence in the three hydrologic conditions. The high species richness of fish in the small, vegetated lakes was related to the high spatial heterogeneity during different hydrological conditions. Disturbances in the hydrological pulses could reduce the biodiversity by modifying the connectivity of the floodplain with the river channel. Conservation of these vegetated wetlands requires maintenance of actual width range of connectivity that provide diverse habitat along the time.Neste artigo analisamos as mudanças na composição e abundância das assembléias de peixes de sete áreas úmidas de planície de inundação com vegetação e com diferentes conectividades e em diferentes condições hidrológicas: depois de uma conexão prolongada da planície de inundação com o canal principal, durante o recuo das águas e após um isolamento prolongado. Nós também investigamos o tamanho e abundância das espécies migratórias de grande tamanho encontradas nestas áreas úmidas e os recursos alimentares explorados pelas espécies dominantes. Os peixes foram capturados com rede durante o dia (8.0 m x 1.50 m, malha de 5 mm nos bancos de macrófitas. Apesar do alto número de espécies registradas (100, a riqueza de espécies nas amostras variou entre 7 e 31, de acordo com o local e data de coleta. A análise de cluster indicou uma baixa similaridade entre os locais tanto durante o período de isolamento como no de conexão prolongada. A substituição de espécies decresceu do período de cheia (? = 40.33 a vazante (? = 33.83, com o valor mínimo de índice de diversidade beta obtido durante o isolamento das áreas úmidas da planície de inundação (? = 26.83. Os resultados indicaram que diferentes populações dominantes de peixes ocorrem em condições hidrológicas diferentes, mesmo quando fases de cheia e de isolamento ocorreram na mesma estação em anos diferentes. A ordenação (NMDS indicou a importância das condições hidrológicas na estruturação das assembléias de peixes na planície de inundação estudada. Caracídeos de pequeno tamanho, tipicamente associados à macrófitas, dominaram a assembléia de peixes, enquanto que indivíduos jovens de espécies de maior porte e migratórias f

Juan José Neiff

2009-03-01

184

Ethnic Differences in Eating Disorder Symptoms among College Students: The Confounding Role of Body Mass Index.  

Science.gov (United States)

Explored the role of body mass index (BMI) in eating disorders among Hispanic, Asian American, and non-Hispanic white female college students. Data from student surveys indicated that after controlling for BMI, ethnic differences in eating disorder symptoms of concern about weight and shape disappeared, but differences in restrained eating…

Arriaza, Cecilia A.; Mann, Traci

2001-01-01

185

Multifractal analysis of SSEC in Chinese stock market: A different empirical result from Heng Seng index  

Science.gov (United States)

In this paper, high frequency (per 5 min) data of Shanghai Stock Exchange Composite index (SSEC) from January 1999 to July 2001 is analyzed by multifractal. We find that the correlation of the parameters of the multifractal spectra with the variation of daily return Z in SSEC is noticeably different from that in previous studies of Heng Seng index in Hong Kong stock market [Sun et al., Phys. A 291 (2001) 553-562; Sun et al., Phys. A 301 (2001) 473-482]. So, we suppose that there may not be a universal rule for the dependence of the parameters of the multifractal spectra with daily return of a stock index. Then, we construct a new measurement of market risk based on multifractal spectra, and test its ability of predicting index fluctuations with a more thorough method than that in Sun et al. [Phys. A 301 (2001) 473-482].

Wei, Yu; Huang, Dengshi

2005-09-01

186

Índice de cobertura vegetal e sua modelagem para cultivares de soja no sul de Minas Gerais / Index of vegetal cover and its modeling for soybean cultivars in the south of Minas Gerais  

Scientific Electronic Library Online (English)

Full Text Available A cobertura vegetal do solo é decisiva para redução dos efeitos erosivos do impacto direto das gotas de chuva na superfície do solo. Desta forma, objetivou-se com este estudo determinar o índice de cobertura vegetal (CV) e desenvolver modelos para sua estimativa para a cultura da soja, usando os atr [...] ibutos climáticos no período de chuvas intensas no Sul de Minas Gerais. As determinações da CV foram feitas semanalmente, na área experimental do Departamento de Ciência do Solo, Universidade Federal de Lavras, no período de novembro de 1999 a maio de 2000, em 28 cultivares de soja com potencial para cultivo nesta região. Para avaliação da cobertura vegetal foi utilizada a metodologia descrita por Stocking (1988). Na modelagem procurou-se relacionar a CV com os valores acumulados dos seguintes atributos climáticos: temperatura média (Tmed), precipitação (PREC) e umidade relativa do ar (UR). Os valores de cobertura vegetal apresentaram uma amplitude de variação de 56 a 83%, sendo BR 162, LO 12 L e M. Soy 108 as cultivares mais eficientes e FT Abyara e Tucano as menos eficientes. O hábito diferencial de crescimento das cultivares ajuda a explicar esse comportamento. O modelo ajustado adequado para estimativa da CV foi: CV = 116589,976 + 0,422 . Tmed + 0,132 . PREC - 0,095 . UR + 0,000024 . Tmed², R² = 0,99 (P Abstract in english Vegetal cover of soil is decisive to reduce the erosive effects of direct impact of raindrops on the soil surface. Therefore, the objective of this study was to determine the vegetal cover (CC) index and to develop models to estimate it for soybean cultivars, using climatic attributes in the period [...] of intense rains in the South of the State of Minas Gerais in Brazil. CC was measured weekly in the experimental area of the Department of Soil Science, Federal University of Lavras, from November 1999 to May 2000, for 28 soybean cultivars with yield potential in this region. To evaluate the vegetal cover, the method described by Stocking (1988) was used. In the modeling, CC was related with the accumulated values of following climatic attributes: medium temperature (Tmed), precipitation (PREC), and relative humidity of the air (RH). Vegetal cover values presented an amplitude from 56 to 83%, being BR 162, LO 12 L and M. Soy 108, the more efficient cultivars, and the FT Abyara and Tucano, the least efficient ones. The differential growth habit of the cultivars helps to explain this behavior. The best adjusted model for the estimative of CC was: CC = 116589.976 + 0.422, Tmed + 0.132, PREC - 0.095, RH + 0.000024 Tmed², R² = 0.99 (P

Vitor Corrêa de Mattos, Barreto; Marx Leandro Naves, Silva; Nilton, Curi; Flávio Pereira de, Oliveira; Pedro Milanez de, Rezende; Daniel Ferreira, Furtado.

1168-11-01

187

Towards a tool to design vegetated strips for mitigation of pesticides transfers in surface runoff. Assessment of different scenarios  

OpenAIRE

Vegetated strips can be useful in order to limit pesticides fluxes transferred from agricultural fields towards surface waters. However, these structures must be relevantly situated and well proportioned to be efficient enough. In this study, we assess the efficiencyof vegetative strips to limit surface runoff in contrasted situations, representative of different parts of France. The modelling tool is a version of HYDRUS 2D coupled with a kinematic wave equation, which allows to represent joi...

Carluer, N.; Giannone, G.; Gouy, V.; Gril, J. J.

2009-01-01

188

Recovery of different waste vegetable oils for biodiesel production: a pilot experience in Bahia State, Brazil.  

Science.gov (United States)

In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH. The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated. PMID:23993759

Torres, Ednildo Andrade; Cerqueira, Gilberto S; Tiago, M Ferrer; Quintella, Cristina M; Raboni, Massimo; Torretta, Vincenzo; Urbini, Giordano

2013-12-01

189

Cholesterol levels and nutritional composition of commercial layers eggs fed diets with different vegetable oils  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english This experiment aimed at evaluating the effects of the supplementation of different vegetable oils at different levels to the diet of commercial layers on egg cholesterol levels and nutritional composition (proteins, total solids, lipids, and ashes) for 112 days. Birds were distributed according to [...] a completely randomized experimental design with 10 treatments (T1 - control; T2 - inclusion of 2.5% rapeseed oil; T3 - inclusion of 2.5% canola oil; T4 - inclusion of 2.5% soybean oil; T5 - inclusion of 5% rapeseed oil; T6 - inclusion of 5% canola oil; T7 - inclusion of 5% soybean oil; T8 - inclusion of 2.5% rapeseed oil + 2.5% soybean oil; T9 - inclusion 2.5% canola oil + 2.5% soybean oil; T10 - inclusion of 2.5% rapeseed oil + 2.5% canola oil) of six replicates of eight birds each, totaling 480 birds. Yolk cholesterol levels and nutritional composition were determined on days 20, 60 and 112 days of the experimental period. Data obtained during the experimental period were submitted to analysis of variance. Egg yolks produced by layer fed oils presented lower cholesterol levels after 20 days of inclusion in the experimental diets. On days 60 and 112, cholesterol levels were higher. It was concluded that supplementing layer diets with vegetable oils rich in polyunsaturated fatty acids does not change the nutritional composition of egg yolks. The supply of diets containing oils rich in polyunsaturated fatty acids does not reduce yolk cholesterol content.

ABG, Faitarone; EA, Garcia; R de O, Roça; H de A, Ricardo; E N de, Andrade; K, Pelícia; F, Vercese.

2013-03-01

190

Variations in chemical composition of grass clover mixtures over the vegetation season in different agroecological conditions  

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Full Text Available The aim of the current investigation carried out on 6 family farms in 6 counties was to determine seasonal variations in chemical composition of domestic and Canadian grass-clover mixture (GCM. The study was arranged as complete randomly design on 1 ha area at each of the family farm involved (0.5 ha domestic, 0.5 ha Canadian GCM. The sward at each family farm was cut five times over the vegetation season. GCM samples were analyzed by NIR spectroscopy (NIR instrument, Foss, Model 6500 to determine: dry matter (DM, organic matter (OM, crude protein (CP, neutral detergent fiber (NDF, metabolic energy (ME, digestibility of OM in DM (D-value and water-soluble carbohydrates (WSC. No differences in chemical composition between the two GCM were observed, but among locations for DM, OM and WSC. The interaction of mixture x location was significant (P0.05. This means that no significant differences were noticed between mixtures at the same term of cutting, but for all of the investigated parameters among cuttings. There quality of GCM was increasing over the season as seen from its relative increase in CP from the first (112.9 g kg-1 to the fifth cut (185.9 g kg-1. NDF was higher over the whole vegetation season. The last cut showed significantly lower NDF (628.6 g kg-1, higher ME (10,73 MJ kg-1, D-value (71.6 and WSC (56.3 g kg-1.

Goran Per?ulija

2005-10-01

191

Soil contamination by phthalate esters in Chinese intensive vegetable production systems with different modes of use of plastic film  

International Nuclear Information System (INIS)

The concentrations of six priority phthalic acid esters (PAEs) in intensively managed suburban vegetable soils in Nanjing, east China, were analyzed using gas chromatography–mass spectrometry (GC–MS). The total PAE concentrations in the soils ranged widely from 0.15 to 9.68 mg kg?1 with a median value of 1.70 mg kg?1, and di-n-butyl phthalate (DnBP), bis-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) were the most abundant phthalate esters. Soil PAE concentrations depended on the mode of use of plastic film in which PAEs were incorporated as plasticizing agents and both the plastic film and poultry manure appeared to be important sources of soil PAEs. Vegetables in rotation with flooded rice led to lower concentrations of PAEs in soil. The results indicate that agricultural plastic film can be an important source of soil PAE contamination and further research is required to fully elucidate the mechanisms of PAE contamination of intensive agricultural soils with different use modes of use of plastic film. -- Highlights: •Phthalate esters in soils from suburban intensive vegetable production systems were investigated. •Phthalate levels and risks of the vegetable soils with different plastic film use modes were examined. •Sources of phthalate esters in vegetable production soils were analyzed. -- PAE contamination of intensively managed vegetable soils varied widely depending on the mode of use of plastic film in different production systems

192

Fiber Bragg Grating Modeling, Characterization and Optimization with different index profiles  

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Full Text Available This paper presents the modeling and characterization of an optical fiber grating for maximum reflectivity, minimum side lobe power wastage. Grating length and refractive index profile are the critical parameters in contributing to performance of fiber Bragg grating. The reflection spectra and side lobes strength were analyzed with different lengths and different refractive index profiles. podization techniques are used to get optimized reflection spectra. The simulations are based on solving coupled mode equations by transfer matrix method that describes the interaction of guided modes.

SUNITA UGALE

2010-09-01

193

The regularities of mutagenic action of ?-radiation on vegetative Bacillus subtilis cells with different repair genotype  

International Nuclear Information System (INIS)

The regularities of induction of his-?his+ mutations in vegetative Bacillus subtilis cells with different repair capacity after ?-irradiation have been studied. The wild type cells, polAl, recE4, recA, recP, add5, recH were used in experiments. It was shown that radiation-induced mutagenesis is determined by a repair genotype of cells. The blocking of different reparation genes is reflected on mutagenesis ratio by various ways. A frequency of induction mutations in polA strain is higher than in wild type cells and it is characterized by the linearly-quadratic dose curve. The different rec- strains that belong to various epistatic groups reveal an unequal mutation induction. The add5 and recP strains are characterized by the high-level induction mutations in contrast with the wild type cells. The mutagenesis in recE and recH strains, on the contrary, sharply reduces. The different influence of rec genes inhering to various epistatic groups on mutagenesis in Bacillus subtilis cells probably reflects the complex organization of their SOS repair system. (author)

194

Large Differences in Terrestrial Vegetation Production Derived from Satellite-Based Light Use Efficiency Models  

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Full Text Available Terrestrial gross primary production (GPP is the largest global CO2 flux and determines other ecosystem carbon cycle variables. Light use efficiency (LUE models may have the most potential to adequately address the spatial and temporal dynamics of GPP, but recent studies have shown large model differences in GPP simulations. In this study, we investigated the GPP differences in the spatial and temporal patterns derived from seven widely used LUE models at the global scale. The result shows that the global annual GPP estimates over the period 2000–2010 varied from 95.10 to 139.71 Pg C?yr?1 among models. The spatial and temporal variation of global GPP differs substantially between models, due to different model structures and dominant environmental drivers. In almost all models, water availability dominates the interannual variability of GPP over large vegetated areas. Solar radiation and air temperature are not the primary controlling factors for interannual variability of global GPP estimates for most models. The disagreement among the current LUE models highlights the need for further model improvement to quantify the global carbon cycle.

Wenwen Cai

2014-09-01

195

Non-Starchy Vegetables  

Science.gov (United States)

... Count Glycemic Index Low-Calorie Sweeteners Sugar and Desserts Fitness Exercise & Type 1 Diabetes Get Started Safely ... the Best Choices? The best choices are fresh, frozen and canned vegetables and vegetable juices without added ...

196

The environmental vegetation index: A tool potentially useful for arid land management. [Texas and Mexico, plant growth stress due to water deficits  

Science.gov (United States)

The NOAA-6 AVHRR data sets acquired over South Texas and Mexico during the spring of 1980 and after Hurricane Allen passed inland are analyzed. These data were processed to produce the Gray-McCrary Index (GMI's) for each pixel location over the selected area, which area contained rangeland and cropland, both irrigated and nonirrigated. The variations in the GMI's appear to reflect well the availability of water for vegetation. The GMI area maps are shown to delineate and to aid in defining the duration of drought; suggesting the possibility that time changes over a selected area could be useful for irrigation management.

Gray, T. I., Jr.; Mccrary, D. G. (principal investigators)

1981-01-01

197

Effects of vegetation structure on biomass accumulation in a Balanced Optimality Structure Vegetation Model (BOSVM v1.0  

Directory of Open Access Journals (Sweden)

Full Text Available A myriad of interactions exist between vegetation and local climate for arid and semi-arid regions. Vegetation function, structure and individual behavior have large impacts on carbon–water–energy balances, which consequently influence local climate variability that, in turn, feeds back to the vegetation. In this study, a conceptual vegetation structure scheme is formulated and tested in the new Balanced Optimality Structure Vegetation Model (BOSVM to explore the importance of vegetation structure and vegetation adaptation to water stress on equilibrium biomass states. Surface energy, water and carbon fluxes are simulated for a range of vegetation structures across a precipitation gradient in West Africa and optimal vegetation structures that maximize biomass for each precipitation regime are determined. Two different strategies of vegetation adaptation to water stress are included. Under dry conditions vegetation tries to maximize the water use efficiency and leaf area index as it tries to maximize carbon gain. However, a negative feedback mechanism in the vegetation–soil water system is found as the vegetation also tries to minimize its cover to optimize the surrounding bare ground area from which water can be extracted, thereby forming patches of vertical vegetation. Under larger precipitation, a positive feedback mechanism is found in which vegetation tries to maximize its cover as it then can reduce water loss from bare soil while having maximum carbon gain due to a large leaf area index. The competition between vegetation and bare soil determines a transition between a "survival" state to a "growing" state.

Z. Yin

2014-05-01

198

Chemical Composition, Fatty Acids Content and Glycemic Index of Two Different Types of Omani Halwa  

OpenAIRE

The study evaluated the chemical composition, fatty acids contents and Glycemic Index (GI) of two different types (white and black) of Omani halwa. Representative samples of Omani halwa were collected from the local market. The proximate composition and energy contents of white and black halwa did not vary significantly (p

Amanat Ali; Al-zuhaibi, Khalid M.; Waly, Mostafa I.; Al-alawi, Ahmed A.; Al-sabahi, Jamal N.; Devarajan Sankar

2013-01-01

199

Exploration of Loggerhead Shrike Habitats in Grassland National Park of Canada Based on in Situ Measurements and Satellite-Derived Adjusted Transformed Soil-Adjusted Vegetation Index (ATSAVI  

Directory of Open Access Journals (Sweden)

Full Text Available The population of loggerhead shrike (Lanius ludovicianus excubutirudes in Grassland National Park of Canada (GNPC has undergone a severe decline due to habitat loss and limitation. Shrike habitat availability is highly impacted by the biophysical characteristics of grassland landscapes. This study was conducted in the west block of GNPC. The overall purpose was to extract important biophysical and topographical variables from both SPOT satellite imagery and in situ measurements. Statistical analysis including Analysis of Variance (ANOVA, measuring Coefficient Variation (CV, and regression analysis were applied to these variables obtained from both imagery and in situ measurement. Vegetation spatial variation and heterogeneity among active, inactive and control nesting sites at 20 m × 20 m, 60 m × 60 m and 100 m × 100 m scales were investigated. Results indicated that shrikes prefer to nest in open areas with scattered shrubs, particularly thick or thorny species of smaller size, to discourage mammalian predators. The most important topographical characteristic is that active sites are located far away from roads at higher elevation. Vegetation index was identified as a good indicator of vegetation characteristics for shrike habitats due to its significant relation to most relevant biophysical factors. Spatial variation analysis showed that at all spatial scales, active sites have the lowest vegetation abundance and the highest heterogeneity among the three types of nesting sites. For all shrike habitat types, vegetation abundance decreases with increasing spatial scales while habitat heterogeneity increases with increasing spatial scales. This research also indicated that suitable shrike habitat for GNPC can be mapped using a logistical model with ATSAVI and dead material in shrub canopy as the independent variables.

Li Shen

2013-01-01

200

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ISSN: 2255-2863 is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence, and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.

Antonio Juan Sánchez

2013-07-01

201

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ISSN: 2255-2863 is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence, and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.

Antonio Juan Sánchez

2012-09-01

202

STUDY OF SACRAL INDEX: COMPARISON BETWEEN DIFFERENT REGIONAL POPULATIONS OF INDIA AND ABROAD  

Directory of Open Access Journals (Sweden)

Full Text Available Identification of sex by human skeletal remains is a critical problem and is very important in anthropological and medico legal works. Bones often survive the process of decay and therefore provide the major evidence of human age and sex after death. Over the years different authors had carried various types of measurements on human sacra of different races and regions. The present study carried out 81 sacra of unknown sex contains 45 male and 36 female sacra identified by physical characteristics. They were collected from Telangana and Andhra Pradesh region. India may be divided into four regions like North part, South part, West part, and East part for different study purpose on local population. In the present study mean sacral index in males is 104.08 and females are 115.72. The male mean sacral index value of present study is more than the values of Eastern part, north part, other worker of Southern part of India and western part except in Western part in Western Rajasthan population. The female mean sacral index value of present study is higher than the observation of Eastern part, other workers of Southern part of India, Varanasi and Jammu of north part of India and Saurashtra region of western region of India. Observations of the workers from remaining areas of Western part of India and Agra region of North India is higher than the present study. The studies on Indian population suggest that mean sacral index in females is higher than that of males.

Poornima Janipati

2014-10-01

203

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan SÁNCHEZ

2012-07-01

204

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan SÁNCHEZ

2013-07-01

205

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society. We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan SÁNCHEZ

2013-05-01

206

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan Sánchez

2013-11-01

207

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan Sánchez

2013-08-01

208

Diagnostic Utility of WISC-IV General Abilities Index and Cognitive Proficiency Index Difference Scores among Children with ADHD  

Science.gov (United States)

The Wechsler Intelligence Scale for Children-Fourth Edition General Abilities Index and Cognitive Proficiency Index have been advanced as possible diagnostic markers of attention deficit hyperactivity disorder. This hypothesis was tested with a hospital sample with attention deficit hyperactivity disorder (n = 78), a referred but nondiagnosed…

Devena, Sarah E.; Watkins, Marley W.

2012-01-01

209

How does feed with different levels of vegetable origin affect the sensory quality of ice storage Rainbow trout (Oncorhynchus mykiss)?  

DEFF Research Database (Denmark)

Background Fish from the aquaculture sector make up a steep raising share of the total fish consumed and play in that respect an essential role. The most important farmed fish in Denmark is rainbow trout (Oncorhynchus mykiss). However the aquaculture sector, raising fish species which are primarily carnivores, is facing major challenges as a consequence of the limited access in future sustainable resources of wild fish or other sea living organisms from a lower trophic level for feed production. Consequently, alternative feeding regimes are now considered e.g. use of components of vegetable origin such as soy oil or rapeseed oil combined with vegetable proteins. Such a change in feeding regime will result in a “green fish” and may affect flesh quality and eating quality. The objective was to study the effect of vegetable based feed on sensory of ice storage farmed rainbow trout. Experimental design and methods Feed trials Rainbow trout were farmed in tanks at Biomar A/S, Hirtshals and fed on six different diets covering only marine, only vegetables and mixture of marine and vegetable feeds. Trout for the quality study were slaughtered, vacuum-packed and stored at -80°C until analysis. Sensory Quality Changes in sensory quality were determined by objective descriptive sensory methods using profiling carried out by a trained panel. The fish samples were thawed and ice storage for 3, 5, 7 and 12 days. Results The sensory characterization of the trout feed with 100% marine and 100% vegetable feed showed after 3 days of ice storage that the trout feed with marine fed were more firm, juicy and the texture was more flacky that trout feed with vegetable feed. This sensory difference increased with increasing ice storage.

Hyldig, Grethe; Nielsen, Henrik Hauch

210

Effects of different media on vegetative growth of two Lilium cultivars in soilless culture  

Directory of Open Access Journals (Sweden)

Full Text Available Strong, tall and healthy stems, as well as green background by means of leaves, are very important characters in marketing of cut flowers including Lily (Lilium. Also, in order to reuse the bulbs for next crop production, they should have enough stored materials and perimeter. This investigation was conducted to evaluate the effects of different media on some vegetative characters of two Lillium cultivars in greenhouse conditions and determine the most suitable medium. The experiment was based on randomized complete design with two cultivars namely Bernini (Oriental and Cebdazzle (Asiatic and 4 replicates. Ten treatments of the experiment were organic and mineral media including cocopeat, sand, vermiculite, perlite and mixture of each two media at equal volumes (50: 50. All the pots were fertigated daily by 250 ml of Hoagland half strength solution. Means were compared by Duncan multiple range test at 5% probability level. The results showed superiority of cocopeat over other media in terms of plant chlorophyll content, fresh and dry weight of leaves and stem, leaf area, height, stem diameter, number of leaves, and bulb perimeter in both cultivars. Root length of both cultivars reached the highest using the mixture of perlite and cocopeat. The performance of Cebdazzle cv. against Bernini cv. regarding fresh and dry weight of leaves, leaf area, stem diameter, number of leaves, stem dry weight and root length were better in all the media. While, mean chlorophyll content and fresh weight of stems in Bernini was significantly higher than Cebdazzle.

A. Khaligy

2011-07-01

211

Essential and non-essential elements in natural vegetation in southern Norway: contribution from different sources.  

Science.gov (United States)

Concentrations of essential and non-essential elements in five widespread species of natural boreal vegetation were studied with respect to seasonal variation and contribution from different sources. The plant species included in the study were Betula pubescens, Sorbus aucuparia, Vaccinium myrtillus, Vaccinium uliginosum, Calluna vulgaris and Deschampsia flexuosa. Concentrations of elements essential to plants remained essentially constant or decreased slightly throughout the growing season. Concentrations of most non-essential elements increased or tended to increase on a dry mass basis from June to July as well as from July to September. The increasing trend for these elements was observed for all species except C. vulgaris. Principal component analysis (PCA) of the material indicated a common source for many of the non-essential elements; Sc, Ti, V, Ga, As, Y, Sb, lanthanides, Pb, Bi, and U, i.e. both elements presumably of geogenic origin and elements associated with trans-boundary air pollution. Uptake by plant roots appeared to be the main source of nutrient elements as well as some non-essential elements. PMID:25268568

Nordløkken, Marit; Berg, Torunn; Flaten, Trond Peder; Steinnes, Eiliv

2015-01-01

212

Influence of different planting seasons of six leaf vegetables on residues of five pesticides.  

Science.gov (United States)

To investigate the influence of different planting seasons on the dissipation of pesticides, field experiments of thiophanate-methyl, metalaxyl, fluazifop-P-butyl, chlorpyrifos, and ?-cyhalothrin on six crops including pakchoi, rape, crown daisy, amaranth, spinach, and lettuce were designed and conducted. In this study, a high-performance liquid chromatography and electrospray ionization-tandem mass spectrometer with multiple reaction monitoring was used to simultaneously determine thiophanate-methyl and its metabolite carbendazim, metalaxyl, and fluazifop-P-butyl in various samples; gas chromatography with an electron capture detector was used to detect chlorpyrifos and ?-cyhalothrin. The limits of quantitation (LOQs) of these six pesticides were in the range of 0.001-0.01 mg kg(-1) for all samples, and the average recoveries of all pesticides ranged from 60.1 to 119.1% at 0.01 and 0.1 mg kg(-1) spiked levels. The relative standard deviation (RSD) ranged from 1.1 to 13.9%. All maximal concentrations of the six pesticides in six leaf vegetables in autumn were higher than in summer in Beijing. For most pesticides half-lives in autumn were longer than in summer. The results showed that the initial concentration, maximal concentration, and half-lives of pesticides were influenced not only by environmental factors such as light, heat, moisture, and rainy climate but also by plant matrices. PMID:23978278

Fan, Sufang; Deng, Kailin; Yu, Chuanshan; Zhao, Pengyue; Bai, Aijuan; Li, Yanjie; Pan, Canping; Li, Xuesheng

2013-09-25

213

Sensitivity study of land biosphere CO2 exchange through an atmospheric tracer transport model using satellite-derived vegetation index data  

International Nuclear Information System (INIS)

We develop a simple, globally uniform model of CO2 exchange between the atmosphere and the terrestrial biosphere by coupling the model with a three-dimensional atmospheric tracer transport model using observed winds, and checking results against observed concentrations of CO2 at various monitoring sites. CO2 fluxes are derived from observed greenness using satellite-derived Global Vegetation Index data, combined with observations of temperature, radiation, and precipitation. We explore a range of CO2 flux formulations together with some modifications of the modelled atmospheric transport. We find that while some formulations can be excluded, it cannot be decided whether or not to make CO2 uptake and release dependent on water stress. It appears that the seasonality of net CO2 fluxes in the tropics, which would be expected to be driven by water availability, is small and is therefore not visible in the seasonal cycle of atmospheric CO2. The latter is dominated largely by northern temperate and boreal vegetation, where seasonality is mostly temperature determined. We find some evidence that there is still considerable CO2 release from soils during northern-hemisphere winter. An exponential air temperature dependence of soil release with a Q10 of 1.5 is found to be most appropriate, with no cutoff at low freezing temperatures. This result is independent of the year from which observed winds were taken. This is remarkable insofar as year-to-year changes in modelled CO2 concentrations caused by changes in the wind data clearly outweigh those caused by year-to-year variability in the climate and vegetation index data. (orig.)

214

Summary of the especies of Spanish vegetation sensitive to different pollutants  

International Nuclear Information System (INIS)

A detail literature review of the sensitivity of the species of Spanish vegetation to various pollutants was made. An impact scale was created to describe the qualitative degree of sensitivity to which each specie is affected by major atmospheric pollutants: very sensitive, sensitive, intermediate sensitive and resistent. This type of study, combined with studies of emission, concentration and dispersion of air pollution, is of great interest to evaluate the environmental impact to the vegetation community. (author) 45 refs

215

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Blood pressure (BP variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM. We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI. Methods and Results In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time, standard deviation (SD of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (? 0.90 or ? 1.40 was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007. In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04. In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P Conclusion Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

Moreira Leila B

2010-11-01

216

Growth and photosynthetic capacity in two woody species of cerrado vegetation under different radiation availability  

Directory of Open Access Journals (Sweden)

Full Text Available Seedlings of two woody species of cerrado vegetation, Copaifera langsdorffii and Eriotheca gracilipes, were studied under three different radiation availability (100, 80 and 30% transmittance. Full solar radiation brought about more biomass, higher total leaf area, higher maximal photosynthesis per crown on area or on mass bases and higher photosynthetic capacity on area bases. Only the photosynthetic capacity values on leaf mass bases were higher in both species under low radiation availability (80 and 30% transmittance. The differences of accumulated biomass appeared more clearly after 4 months of sowing but the root/shoot dry biomass ratio and height were maintained constant for both species independently of the available radiation. Cultivated under full solar radiation both species will be able to cover more suitable the two processes during seedling's phase: growth and defense.Duas espécies de cerrado (Copaifera langsdorffii e Eriotheca gracilipes foram cultivadas sob três diferentes condições de radiação (100, 80 e 30% de transmitância. A radiação solar plena proporcionou as condições mais favoráveis para o desenvolvimento das espécies: maior acúmulo de biomassa total, maior área foliar total, maior fotossíntese potencial por copa expressa em área ou em massa e maior capacidade fotossintética expressa em área foliar. Somente os valores de capacidade fotossintética expressa em massa foram maiores sob baixa radiação (80 e 30% de transmitância para ambas as espécies. As diferenças de biomassa acumulada apareceram mais claramente após os 4 meses de plantio, mas a relação massa seca raiz/parte aérea e a altura foram mantidas independentes da radiação disponível para ambas as espécies. Sob 100% de transmitância estas espécies apresentaram um balanço de carbono mais positivo e condições mais favoráveis para suprir as duas principais demandas neste estágio do ciclo de vida da planta: o crescimento e a defesa.

Carlos Cesar Ronquim

2003-03-01

217

Growth and photosynthetic capacity in two woody species of cerrado vegetation under different radiation availability  

Scientific Electronic Library Online (English)

Full Text Available Duas espécies de cerrado (Copaifera langsdorffii e Eriotheca gracilipes) foram cultivadas sob três diferentes condições de radiação (100, 80 e 30% de transmitância). A radiação solar plena proporcionou as condições mais favoráveis para o desenvolvimento das espécies: maior acúmulo de biomassa total, [...] maior área foliar total, maior fotossíntese potencial por copa expressa em área ou em massa e maior capacidade fotossintética expressa em área foliar. Somente os valores de capacidade fotossintética expressa em massa foram maiores sob baixa radiação (80 e 30% de transmitância) para ambas as espécies. As diferenças de biomassa acumulada apareceram mais claramente após os 4 meses de plantio, mas a relação massa seca raiz/parte aérea e a altura foram mantidas independentes da radiação disponível para ambas as espécies. Sob 100% de transmitância estas espécies apresentaram um balanço de carbono mais positivo e condições mais favoráveis para suprir as duas principais demandas neste estágio do ciclo de vida da planta: o crescimento e a defesa. Abstract in english Seedlings of two woody species of cerrado vegetation, Copaifera langsdorffii and Eriotheca gracilipes, were studied under three different radiation availability (100, 80 and 30% transmittance). Full solar radiation brought about more biomass, higher total leaf area, higher maximal photosynthesis per [...] crown on area or on mass bases and higher photosynthetic capacity on area bases. Only the photosynthetic capacity values on leaf mass bases were higher in both species under low radiation availability (80 and 30% transmittance). The differences of accumulated biomass appeared more clearly after 4 months of sowing but the root/shoot dry biomass ratio and height were maintained constant for both species independently of the available radiation. Cultivated under full solar radiation both species will be able to cover more suitable the two processes during seedling's phase: growth and defense.

Carlos Cesar, Ronquim; Carlos Henrique B. de A., Prado; Nádia Figueiredo de, Paula.

2003-03-01

218

Energy partitioning and environmental influence factors in different vegetation types in the GEWEX Asian Monsoon Experiment  

Science.gov (United States)

Environmental influences upon energy balance in areas of different vegetation types (i.e., forest at Kog-Ma in Thailand and at Yakutsk in Russia, grassland at Amdo in Chinese Tibet and at Arvaikheer in Mongolia, and mixed farmland at Tak in Thailand) in the GEWEX Asian Monsoon Experiment were investigated. The sites we investigated are geographically and climatologically different; and consequently had quite large variations in temperature ( T), water vapor pressure deficit (VPD), soil moisture (SM), and precipitation (PPT). During May-October, the net radiation flux ( R n) (in W·m-2) was 406.21 at Tak, 365.57 at Kog-Ma, 390.97 at Amdo, 316.65 at Arvaikheer, and 287.10 at Yakutsk. During the growing period, the R n partitioned into latent heat flux ( ?E/ R n) was greater than that partitioned into sensible heat flux ( H/ R n) at Tak and at Kog-Ma. In contrast, ?E/ R n was lower than H/ R n at Arvaikheer, H/ R n was less than ?E/ R n between DOY 149 and DOY 270 at Amdo, and between DOY 165 and DOY 235 at Yakutsk. The R n partitioned into ground heat flux was generally less than 0.15. The short-wave albedo was 0.12, 0.18, and 0.20 at the forest, mixed land, and grass sites, respectively. At an hourly scale, energy partitions had no correlation with environmental factors, based on average summer halfhourly values. At a seasonal scale energy partitions were linearly correlated (usually p<0.05) with T, VPD, and SM. The ?E/ R n increased with increases in SM, T, and VPD at forest areas. At mixed farmlands, ?E/ R n generally had positive correlations with SM, T, and VPD, but was restrained at extremely high values of VPD and T. At grasslands, ?E/ R n was enhanced with increases of SM and T, but was decreased with VPD.

Liu, Fengshan; Tao, Fulu; Li, Shenggong; Zhang, Shuai; Xiao, Dengpan; Wang, Meng

2014-12-01

219

Impact of consumption of vegetable, fruit, grain, and high glycemic index foods on aggressive prostate cancer risk  

OpenAIRE

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing t...

Hardin, Jill; Cheng, Iona; Witte, John S.

2011-01-01

220

Accuracy of the Temperature–Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions  

OpenAIRE

Water deficit indices based on the spatial relationship between surface temperature (Ts) and NDVI, known as triangle approaches, are widely used for drought monitoring. However, their application has been recently questioned when the main factor limiting evapotranspiration is energy. Even though water is the main control in dryland ecosystems, these can also undergo periods of energy and temperature limitation. In this paper we aimed to: (i) evaluate the TVDI (Temperature–Vegetation Dryness...

Garci?a, M.; Ferna?ndez, Ne?stor; Villagarci?a, L.; Domingo, F.; Puigdefa?bregas, Juan; Sandhold, I.

2014-01-01

221

Camera derived vegetation greenness index as proxy for gross primary production in a low Arctic wetland area  

Science.gov (United States)

The Arctic is experiencing disproportionate warming relative to the global average, and the Arctic ecosystems are as a result undergoing considerable changes. Continued monitoring of ecosystem productivity and phenology across temporal and spatial scales is a central part of assessing the magnitude of these changes. This study investigates the ability to use automatic digital camera images (DCIs) as proxy data for gross primary production (GPP) in a complex low Arctic wetland site. Vegetation greenness computed from DCIs was found to correlate significantly (R2 = 0.62, p satellite. An object-based classification based on a bi-temporal image composite was used to classify the study area into heath, copse, fen, and bedrock. Temporal evolution of vegetation greenness was evaluated and modeled with double sigmoid functions for each plant community. GPP at light saturation modeled from eddy covariance (EC) flux measurements were found to correlate significantly with vegetation greenness for all plant communities in the studied year (i.e., 2010), and the highest correlation was found between modeled fen greenness and GPP (R2 = 0.85, p Arctic regions.

Westergaard-Nielsen, Andreas; Lund, Magnus; Hansen, Birger Ulf; Tamstorf, Mikkel Peter

2013-12-01

222

Adapting Extension Food Safety Programming for Vegetable Growers to Accommodate Differences in Ethnicity, Farming Scale, and Other Individual Factors  

Science.gov (United States)

Differences in vegetable production methods utilized by American growers create distinct challenges for Extension personnel providing food safety training to producer groups. A program employing computers and projectors will not be accepted by an Amish group that does not accept modern technology. We have developed an outreach program that covers…

Kline, Terence R.; Kneen, Harold; Barrett, Eric; Kleinschmidt, Andy; Doohan, Doug

2012-01-01

223

Identification and representability of processes controlling unsaturated flow in vegetated soils at differing temporal scales  

Science.gov (United States)

A model describing unsaturated flow in vegetated soil has been developed, coupling plant feedback mechanisms with a finite-difference implementation of Richards' equation. While care has been taken to relate all parameters and processes to physically realistic analogies, moderate uncertainty in a range of parameters is unavoidable due to the need for characterisation of pedo-transfer functions and the complexity of plant water processes. Confidence in model effectiveness has been addressed through simulations of lysimeter experiments undertaken at Imperial College. A highly comprehensive data set consists of measurements on eight lysimeters divided into two sets of four, with the two sets containing different soil types. The water table was maintained at 65 cm below the soil surface, and all possessed a mature crop of perennial ryegrass (Lolium perenne L.) by the start of the experiment. Measurements of soil hydrological status and onsite meteorological data were taken about every quarter of an hour for a period of close to a year, providing detailed information on events within the lysimeters, and the impact of various meteorological conditions over the year. Diurnal variation and seasonal responses are particularly clear. An application of sensitivity and uncertainty analysis to the model, using this detailed data set, has been undertaken. In the performance of the optimisation process, good quality of model definition at both diurnal and seasonal scales is treated as particularly important, as is the effect of measurement error on parameterisation at these different scales. Since we are correcting parameter estimates in the presence of measurement error, it is important to have an understanding of the distortions produced on the outputs by noise. Therefore, a Bayesian framework is used to facilitate the treatment of both measurement and parametric errors, and to allow the inclusion of subjective probability without losing mathematical rigour. Metropolis Hastings Monte-Carlo methods are used to approximate the posterior distribution for parameters of interest. Due to the complicated topology of the posterior probability, a range of different heuristic algorithms, including simulated annealing, has been investigated in order to aid the search for hard to find modes in which the posterior achieves substantial local maxima. Examination of such maxima aids in addressing questions of parameter and overall model identifiability.

Butler, A. P.; Jackson, B. M.

2003-04-01

224

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

International Nuclear Information System (INIS)

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.

225

Numerical Modelling of the Topographic Wetness Index: An Analysis at Different Scales  

OpenAIRE

A variety of landscape properties have been modeled successfully using topographic indices such as topographic wetness index (TWI), defined as ln(a/tan?), where a is the specific upslope area and ? is the surface slope. In this study, 25 m spatial resolution from digital elevation models (DEM) data were used to investigate the scale-dependency of TWI values when converting DEMs to 50 and 100 m. To investigate the impact of different spatial resolution, the two lower resolution DEMs were int...

Anderson Luis Ruhoff; Nilza Maria Reis Castro; Alfonso Risso

2011-01-01

226

Effects of adding bentonite to different substrates on vegetative growth and yield of snap beans (Phaseulus vulgaris L.  

Directory of Open Access Journals (Sweden)

Full Text Available To study the effects of adding a superabsorbent (bentonite to different substrates on the vegetative growth and yield of snap beans, two randomized complete block design experiments with 4 replications were conducted at Greenhouse of Isfahan University of Technology. In the first experiment, 9 treatments including rice hull, saw dust, sand and their combinations, with 10 and 20% superabsorbent (v/v were used. The results showed that the highest stem length, number of nodes and leaves, shoot fresh weight and pod number were observed using rice hull (90%+superabsorbent (10%. The lowest vegetative growth was related to treatments containing sand and superabsorbent. Increasing superabsorbent from 10 to 20% reduced vegetative growth parameters in most cases. Based on the results of the first experiment, sand treatment was deleted and in the second experiment rice hull, saw dust, perlite and their combinations with 5 and 10% superabsorbent were used. The results showed that the highest plant height, number of nodes and leaves, plant dry weight, branch number and yield were obtained in perlite (95%+superabsorbent (5% and pure perlite. Adding 5 and 10% superabsorbent to rice hull and saw dust caused a significant increase in the vegetative growth. This increase was higher for 10% superabsorbent compared to 5% superabsorbent. Finally, the results showed that adding 10% superabsorbent to rice hull and saw dust increased vegetative growth and yield, while it decreased the loss of nutrient solution.

P. Aghdak

2010-12-01

227

Health status of birds fed diets containing three differently processed discarded vegetable-bovine blood-rumen content mixtures.  

Science.gov (United States)

This study was conducted to determine the effect of feeding three differently processed mixtures on health status of broilers. A total of 1080 day-old Marshal broilers were fed; discarded vegetable-fresh bovine blood-fresh rumen digesta (P1), discarded vegetable-ensiled bovine blood-fresh rumen digesta (P2) and discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3) at three levels of inclusion (0, 3 and 6%). Data on blood parameters was taken and were subjected to 3 x 3 factorial arrangements in a completely randomized design. Birds fed P1 had least values (p rumen digesta (P3) up to 6% level of inclusion. PMID:24498799

Ekunseitan, D A; Balogun, O O; Sogunle, O M; Yusuf, A O; Ayoola, A A; Egbeyale, L T; Adeyemi, O A; Allison, I B; Iyanda, A I

2013-04-01

228

A STUDY ON VARIATION IN BIOCHEMICAL ASPECTS OF DIFFERENT TREE SPECIES WITH TOLERANCE AND PERFORMANCE INDEX  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was undertaken to evaluate the variation between biochemical characteristics and air pollution tolerance index (APTI of 6 different plant species. The results of the present study indicate that APTI was significantly correlated with total chlorophyll, ascorbic acid, leaf pH for all species and are the most significant and determining factors on which the tolerance depends. The order of tolerance index of plant species is as follows Saraca indica (13.71, Azadirachta indica (12.98, Shorea robusta (12.64, Eucalyptus sp. (12.61, Ficus religiosa (12.61 and Tectona grandis (13.33. According to anticipated performance index (API all species were tolerant i.e. Azadirachta indica, Ficus religiosa, Saraca indica, Tectona grandis (75%, Shorea robusta and Tectona grandis (68%. The present study suggests that evaluation of plant tolerance and performance index might be very useful in the selection of appropriate species which can be expected to perform well for the development of green environment.

MEHA BORA

2014-03-01

229

The effect of cutting regime on yield of sorghum in different climatic (vegetation seasons  

Directory of Open Access Journals (Sweden)

Full Text Available Forage could be produced on natural grasslands, leys or arable land, but in lowland and in dry areas short season forage crops should be interpolated due to instability of yields from grasslands. Using that pattern, it is possible to better utilize the potential of arable land and the energy of the sun instead of leaving the fields empty (3-8 months, and to produce high yield of quality forage. Sorghum hybrids fit well in that system of forage production on family farms. It could be sown after harvesting of winter and early sown spring crops, and utilized in few cuts during a second part of summer, until the beginning of autumn and appearance of the first frost. Furthermore, it could ensure good yields of quality green forage and the rest quantity could be ensilaged. In that way higher yields of quality forage per hectare could be provided during vegetation season. The experiment was conducted at Maksimir experimental field, Faculty of Agriculture University of Zagreb. The aim of this research was to determine green mass yield (GMY and dry matter yield (DMY of sorghum (cv. Grazer N, at different cutting regime in two various seasons (dry and wet summer. The highest GMY and DMY were obtained when sorghum was cut 2 times at 200 cm height in 2002 and 2003 experimental years. Climatic conditions were better in the year 2002, so in that year GMY varied from 85.2 to 100.7 t/ha, while DMY varied from 18.7 to 31.0 t/ha. In the experimental year 2003 GMY varied from 58.6 to 86.6 t/ha, while DMY varied from 14.6 to 26.6 t/ha. Even in such unfavorable year, as 2003 was, sorghum (cv. Grazer N expressed its great potential for continuing utilization in summer and early autumn.

Darko Uher

2005-01-01

230

Composition, peat-forming vegetation and kerogen paraffinicity of Cenozoic coals: Relationship to variations in the petroleum generation potential (Hydrogen Index)  

Energy Technology Data Exchange (ETDEWEB)

Coals with similar thermal maturity and from the same deposit normally show a considerable range in petroleum generation potential as measured by the Hydrogen Index (HI). This variation may partly be related to variations in plant input to the precursor mires and organic matter preservation. It is widely accepted that some Cenozoic coals and coaly sediments have the potential to generate oil, which is related to the coal's paraffinicity. Coal paraffinicity is not readily reflected in the bulk HI. In this paper, the relationships between measured HI and coal composition, coal kerogen paraffinicity and floral input have been investigated in detail for three sets of coals from Colombia/Venezuela, Indonesia, and Vietnam. The samples in each coal set are largely of iso-rank. The petroleum generation potential was determined by Rock-Eval pyrolysis. Reflected light microscopy was used to analyse the organic matter (maceral) composition and the thermal maturity was determined by vitrinite reflectance (VR) measurements. The botanical affinity of pollen and spores was analysed by palynology. Coal kerogen paraffinicity was determined by ruthenium tetroxide-catalysed oxidation (RTCO) followed by chain length analysis and quantification (mg/g TOC) of the liberated aliphatic chains. The coals are dominated by huminite, in particular detrohuminite. Only the Vietnamese coals are rich in microscopically visible liptinite. The pollen and spores suggest that the coals were derived principally from complex angiosperm mire vegetations, with subordinate proportions of ferns that generally grew in a subtropical to tropical climate. Measured HI values vary considerably, but for the majority of the coals the values lie between approximately 200 mg HC/g TOC and 300 mg HC/g TOC. Aliphatics yielding monocarboxylic acids dominate in the coal kerogen, whereas aliphatics yielding dicarboxylic acids are secondary. However, the dicarboxylic acids show that cross-linking long-chain aliphatics are present in the kerogen structure. All studied coals are paraffinic with C{sub 19-35} aliphatic chains in the kerogen, and the aliphatics in the range C{sub 25-35} show that the coals may have the potential to generate waxy crude oil. The Indonesian coals are richest in long-chain aliphatics and are thus potentially most oil-prone. Multivariate statistical analysis shows that for the present three sample sets variations in HI are positively correlated to different combinations of the C{sub 10+} aliphatic chains in the kerogen and the amount of detrohuminite + liptodetrinite and liptinite. Furthermore, part of the HI can be attributed to hydrogen in compounds with less than 10 carbon atoms, which is the lowest alkyl detected by RTCO analysis, thus representing a potential for generation of gas and light liquid hydrocarbons. The measured HI is therefore not always a good indicator for humic coal's potential to source waxy oil. Vegetational influence (palynology) on the variation of HI cannot be shown within the investigated span of variance and for the present coals. However, it is likely that some of the range in measured HI values is caused by floral vairiations not revealed by the palynological analysis and to variations in the preservation of the organic matter. (author)

Petersen, H.I.; Lindstroem, S.; Nytoft, H.P.; Rosenberg, P. [Geological Survey of Denmark and Greenland (GEUS), Oester Voldgade 10, DK-1350 Copenhagen (Denmark)

2009-04-01

231

Bacteriological quality of vegetables from organic and conventional production in different areas of Korea.  

Science.gov (United States)

Foods grown in organic production systems have been described as representing an increased risk to public health compared with foods from conventional production. Leafy vegetables (spinach, romaine lettuce, and green sesame leaves) grown in organic and conventional systems were collected from various areas in Korea and examined using standard culture methods to compare the microbiological quality of the produce grown in the two agricultural systems. The 354 samples of these leafy vegetables were analyzed for levels of indicator bacteria (aerobic bacteria, coliforms, and Escherichia coli) and the prevalence of the pathogens Staphylococcus aureus, E. coli O157:H7, Listeria monocytogenes, Bacillus cereus, and Salmonella. Aerobic bacteria and coliforms were detected in all vegetable types, but nonpathogenic E. coli was below the limit of detection in all samples. B. cereus was the most prevalent pathogen, found on 7 (11.1%) of the 63 organic spinach samples. The prevalence of S. aureus was highest in organic sesame leaves; it was found on 5 (8.0%) of the 63 samples. The prevalence of L. monocytogenes was highest on organic romaine lettuce and spinach; it was found in 4 (6.4%) of 63 samples of each type of vegetable. E. coli O157:H7 found on only 1 (1.58%) of 55 conventional spinach samples. These results suggest that farming type at most only slightly affects the hygienic quality of leafy vegetables, and no effect was found for sample collection area. Salmonella was not isolated from any of the conventional or organic leafy vegetables. These results do not support the hypothesis that organic produce poses a substantially greater risk of pathogen contamination than does conventional produce. PMID:25198606

Tango, Charles Nkufi; Choi, Na-Jung; Chung, Myung-Sub; Oh, Deog Hwan

2014-08-01

232

Spatial and temporal distribution of litter arthropods in different vegetation covers of Porto Santo Island (Madeira Archipelago, Portugal)  

OpenAIRE

The main objective of this study is to assess the soil diversity and temporal and spatial distribution of litter macro-arthropods, captured with pitfall traps, on different vegetation covers from Porto Santo Island (Portugal) with different soil physical and chemical characteristics. The PCA clearly separated sampling areas geographically more exposed to winds and solar radiation, from the others that were not. In this analysis, seasons seemed to have no influence on this distribution. Non-ex...

Antunes, S. C.; Pereira, R.; Sousa, J. P.; Santos, M. C.; Gonc?alves, F.

2008-01-01

233

The role of vegetated areas on fish assemblage of the Paraná River floodplain: effects of different hydrological conditions  

OpenAIRE

In this paper, we analyze the changes in composition and abundance of fish assemblages in seven vegetated floodplain wetlands with different connectivity across different hydrologic conditions: after a prolonged connection of the floodplain with the main channel, during receding water, and after a prolonged isolation. We also investigated the size and abundance of large-sized migratory species found in these wetlands and the food resources exploited by the dominant fish. Fishes were captured ...

Juan José Neiff; Alicia Poi de Neiff; Cano?n Vero?n, Marta B.

2009-01-01

234

Diversity of Halophyte Desert Vegetation of the Different Saline Habitats in the Valley of Oued Righ, Low Sahara Basin, Algeria  

OpenAIRE

The aim of the present study was to investigate the floristic composition and diversity of the different habitat types in the saline areas of the valley of Oued Righ, locating in the low Sahara basin of Algeria. Three distinct saline habitats were examined: saline soil habitats, subsaline soil habitats, and waterlogged habitats. A total of 67 stands along the study area were investigated using the quadrat method, and different vegetation parameters, such as cover, frequency, density, and Impo...

Belhamra Mohamed; Lahcini Ali; Benhaddya Mohammed Lamine; Bensaha Hocine; Mayouf Rabah; Halis Youcef

2012-01-01

235

An aggregate AQI: Comparing different standardizations and introducing a variability index.  

Science.gov (United States)

Many studies demonstrate a strong relationship between air pollution and respiratory and cardiovascular diseases. For this reason, assessing air pollution, and conveying information about its possible adverse health effects, may encourage population and policy makers to reduce those activities increasing pollution levels. In this paper a relative index of variability, to be associated with the aggregate Air Quality Index (AQI) among pollutants proposed by Ruggieri and Plaia (2011), is developed in order to better investigate air pollution conditions for the whole area of a city/region. The most widely-used and up to date pollution indices, based mainly on AQI computed by the US Environmental Protection Agency (EPA) and often defined by the value of the pollutant with the highest (opportunely standardized) concentration on a given day, aim at warning the people for short term health impact. An aggregate AQI, taking into account the combined effects of all the considered pollutants, gives emphasis to possible chronic health effects and long term damages on environment caused by air pollution. The proposed index of variability adds precious information to the aggregate AQI, as it allows one to know whether the value assumed by the AQI is influenced by one or more pollutants. The two indices are jointly used on simulated data, considering different possible scenarios. Applications to real air pollution data are also reported. Before applying the two indices, the effects of different standardizations on data are evaluated from a theoretical point of view. PMID:22325987

Ruggieri, Mariantonietta; Plaia, Antonella

2012-03-15

236

Effects of vegetation structure on biomass accumulation in a Balanced Optimality Structure Vegetation Model (BOSVM v1.0  

Directory of Open Access Journals (Sweden)

Full Text Available A myriad of interactions exist between vegetation and local climate for arid and semi-arid regions. Vegetation function, structure and individual behavior have large impacts on carbon-water-energy balances, which consequently influence local climate variability that, in turn, feeds back to the vegetation. In this study, a conceptual vegetation structure scheme is formulated and tested in a new carbon-water-energy coupled model to explore the importance of vegetation structure and vegetation adaptation to water stress on equilibrium biomass states. Surface energy, water and carbon fluxes are simulated for a range of vegetation structures across a precipitation gradient in West Africa and optimal vegetation structures that maximizes biomass for each precipitation regime are determined. Two different strategies of vegetation adaptation to water stress are included. Under dry conditions vegetation tries to maximize the Water Use Efficiency and Leaf Area Index as it tries to maximize carbon gain. However, an important negative feedback mechanism is found as the vegetation also tries to minimize its cover to optimize the surrounding bare ground area from which water can be extracted, thereby forming patches of vertical vegetation. Under larger precipitation, a positive feedback mechanism is found in which vegetation tries to maximize its cover as it then can reduce water loss from bare soil while having maximum carbon gain due to a large Leaf Area Index. The competition between vegetation and bare soil determines a transition between a "survival" state to a "growing" state.

Z. Yin

2013-09-01

237

Ultraviolet light induces different spectra of lacI sequence changes in vegetative and conjugating cells of Escherichia coli  

Energy Technology Data Exchange (ETDEWEB)

We have analyzed the nucleotide sequence changes reponsible for mutations from lacI/sup 5/ to lacI/sup -/ induced in ultraviolet light-irradiated, excision-deficient cells. Irradiated cells were either used as donors in the conjugational transfer of an F' lacI/sup 5/ plasmid to SOS-induced, excision-deficient recipients or allowed to continue vegetative growth. In vegetative cells there were about equal numbers of transitions and transversions, but transitions outnumbered transversions by about three to one in exconjugants. About 90% of the single nucleotide substitutions could be assigned to a bipyrimidine target sequence in both sets of data, but they differed with respect to the location of the substitution: more or less equal numbers were found at the 3' and 5' sites of the 3' site. It is also possible that mutations were targeted more commonly at T-C sequences in exconjugants than in vegetative cells, but the evidence for this less secure. We conclude that these results reflect some dissimilarity between vegetative cells and exconjugants in the way damaged DNA is replicated or lesions tolerated, but the particular features of these processes reponsible for the different mutational spectra have not yet been identified.

LeClerc, J.E.; Christensen, J.R.; Tata, P.V.; Christensen, R.B.; Lawrence, C.W. (Rochester Univ., NY (USA). School of Medicine and Dentistry)

1988-10-05

238

Comparing the impacts of hiking, skiing and horse riding on trail and vegetation in different types of forest.  

Science.gov (United States)

Nature-based tourism in protected areas has increased and diversified dramatically during the last decades. Different recreational activities have a range of impacts on natural environments. This paper reports results from a comparison of the impacts of hiking, cross-country skiing and horse riding on trail characteristics and vegetation in northern Finland. Widths and depths of existing trails, and vegetation on trails and in the neighbouring forests were monitored in two research sites during 2001 and 2002. Trail characteristics and vegetation were clearly related to the recreational activity, research site and forest type. Horse trails were as deep as hiking trails, even though the annual number of users was 150-fold higher on the hiking trails. Simultaneously, cross-country skiing had the least effect on trails due to the protective snow cover during winter. Hiking trail plots had little or no vegetation cover, horse riding trail plots had lower vegetation cover than forest plots, while skiing had no impact on total vegetation cover. On the other hand, on horse riding trails there were more forbs and grasses, many of which did not grow naturally in the forest. These species that were limited to riding trails may change the structure of adjacent plant communities in the long run. Therefore, the type of activities undertaken and the sensitivity of habitats to these activities should be a major consideration in the planning and management of nature-based tourism. Establishment of artificial structures, such as stairs, duckboards and trail cover, or complete closure of the site, may be the only way to protect the most sensitive or deteriorated sites. PMID:18930578

Törn, A; Tolvanen, A; Norokorpi, Y; Tervo, R; Siikamäki, P

2009-03-01

239

TERRESTRIAL VEGETATION GREENNESS OF THE LOWER GALVESTON BAY WATERSHED FROM SATELLITE REMOTE SENSING AND ITS RELATION TO WATER AND THE SALINITY REGIME OF THE GALVESTON BAY ESTUARY  

Science.gov (United States)

Spatial and temporal variability of vegetation greenness have been determined for coastal Texas using biweekly Normalized Difference Vegetation Index (NDVI) data derived from the Advanced Very High Resolution Radiometer (AVHRR). Results are presented on relationships between grou...

240

A COMPARISON OF THE SALINITY REGIME ALONG THE TEXAS COAST WITH TERRESTRIAL VEGETATION GREENNESS AND WATER USE IN THE GALVESTON BAY WATERSHED USING REMOTING SENSING  

Science.gov (United States)

Variability in vegetation greenness was determined for the Galveston Bay watershed using biweekly Normalized Difference Vegetation Index (NDVI) data derived from the Advanced Very High Resolution Radiometer (A VHRR) flown on NOAA satellites. NDVI variability was compared with reg...

241

Índices de vegetação simulados de diferentes sensores na estimativa das variáveis biofísicas do feijoeiro / Vegetation indices simulated from different sensors for the estimation of biophysical variables of common bean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar os índices de vegetação e bandas do vermelho e do infravermelho próximo, gerados a partir dos sensores HRVIR, ETM+ e Modis, nas estimativas de índice de área foliar e produtividade da cultura do feijoeiro. O experimento foi realizado em blocos ao acaso, com parc [...] elas subdivididas, com quatro lâminas de irrigação (179,5, 256,5, 357,5 e 406,2 mm), três doses de N (0,0, 80,0 e 160,0 kg ha-1) e quatro repetições. As medidas de reflectância foram obtidas com o Spetron SE-590, no estádio R6 da cultura, nas 48 parcelas. Foram testados: a razão simples, o índice de vegetação por diferença normalizada, índice de vegetação ajustado ao solo e índice de vegetação realçado. Os índices de vegetação foram eficientes na estimativa do índice de área foliar (IAF) e da produtividade da cultura do feijoeiro. Os índices de vegetação e a banda do infravermelho apresentam o mesmo potencial na estimativa do IAF, quando se considera a resolução espectral dos sensores Modis, ETM+ e HRVIR. Abstract in english The objective of this work was to evaluate the vegetation indices and red and infrared bands of the HRVIR, ETM+ and Modis sensors, in the estimations of leaf area index and grain yield of common bean. The experiment was carried out in a randomized block design, with split plots and four irrigation l [...] evels (179.5, 256.5, 357.5, and 406.2 mm), three N rates (0.0, 80.0 and 160.0 kg ha-1), and four replicates. The reflectance measurements were obtained through the Spectron SE-590, at R6 stage, on 48 plots. Simple ratio, normalized difference vegetation index, soil-adjusted vegetation index, and enhanced vegetation index were tested. The vegetation indices were efficient to estimate the leaf area index (LAI) and grain yield. The vegetation indices and infrared band show the same potential to estimate LAI, when considering the spectral resolution of Modis, ETM+ and HRVIR.

Priscylla Ferraz Câmara, Monteiro; Rubens, Angulo Filho; Alexandre Cândido, Xavier; Rodrigo Otávio Câmara, Monteiro.

2013-04-01

242

Different methods for control and comparison of the antioxidant properties of vegetables.  

Czech Academy of Sciences Publication Activity Database

Ro?. 21, ?. 4 (2010), s. 518-523. ISSN 0956-7135 R&D Projects: GA AV ?R(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : antioxidant activity * polyphenols * vegetables Subject RIV: BO - Biophysics Impact factor: 2.812, year: 2010

?íž, Milan; ?ížová, Hana; Denev, P.; Kratchanova, M.; Slavov, A.; Lojek, Antonín

2010-01-01

243

Vegetation productivity patterns at high northern latitudes: do different satellite data sets agree?  

Science.gov (United States)

Satellite records of NDVI form the primary data source to study changes in global vegetation productivity in the last three decades. Creating coherent long-term NDVI records from legacy satellite data sets is challenging because of a.o. the influences of orbital drift, sensor degradation, aerosol spikes from volcanic eruptions, and changing instrument design on reflectance measurements. These issues require corrections to reduce uncertainties in long-term NDVI records. We compared depictions of long-term changes in vegetation productivity over high northern latitudes (>50°N), estimated as trends in growing season NDVI of the most widely used global NDVI data sets. These included the AVHRR based GIMMS-NDVI version G data, and its recent successor version 3g, as well as the shorter NDVI records generated from more modern sensors: SeaWiFS, SPOT-VGT, and MODIS, with the data sets from the latter two sensors adjusted to reduce Bidirectional Reflectance Distribution (BRDF) effects. Our analysis reveals both large geographic areas, totaling 40% of the region, where all data sets indicate similar changes in vegetation productivity over their common temporal record (2002-2008), as well as areas where data sets show conflicting patterns. The newer GIMMS data set (version 3g) shows statistically significant (? = 0.05%) increases in vegetation productivity not seen in its predecessor (version g) in >15% of the study area whereas the reverse is very rare (<3%). The latter has implications for earlier reports based on GIMMS version G, particularly in Eurasia where 'greening' is particularly pronounced in the GIMMS 3g data. Furthermore, the two BRDF-adjusted data sets studied here show diverging patterns of high latitude vegetation productivity, with SPOT-VGT D10 showing much more vegetation 'greening' than either of the GIMMS data sets, and the MODIS data set showing slightly less. We discuss the implications of these findings for inferences made from global NDVI data sets regarding primary productivity changes, and encourage users to combine the analysis of NDVI time series data with complementary data sources where possible, such as field measurements of growth, mortality, vegetation cover and composition, tree and shrub rings, and carbon dioxide exchange.

Beck, Pieter; Guay, Kevin; Buermann, Wolfgang; Baccini, Alessandro; Goetz, Scott

2014-05-01

244

Oxidative changes during ice storage of rainbow trout (Oncorhynchus mykiss) fed different ratios of marine and vegetable feed ingredients  

DEFF Research Database (Denmark)

Recently fish meal and oil have increasingly been replaced with proteins and oils from vegetable sources in the diets of farmed salmonids, but the consequences for the oxidative stability of the resulting fish products have not been investigated. The aim of the present study was to evaluate the influence of feeding regime on composition of rainbow trout fillets, as well as on lipid and protein oxidation during storage on ice. Rainbow trout were fed six different diets, which differed in their levels of marine oil and proteins vs. vegetable oil and protein. Fish fillets were characterised by measurement of fatty acid and amino acid composition, primary and secondary lipid oxidation products, astaxanthin and tocopherol content. Protein oxidation was assessed by measuring protein carbonyl content, oxidised amino acids, sulfhydryl groups and immuno-blotting against carbonyl groups. Feeding regimes significantly influenced fatty acid composition. Replacement of fish oil with vegetable oil reduced formation of primary oxidation products, but the effect on secondary oxidation products differed between different types of volatiles. The differences in protein and amino acid composition were not significant, and there were no clear effects of diets on protein oxidation, but data indicated that compounds present in the marine ingredients might have had an effect on protein oxidation.

Timm Heinrich, Maike; Eymard, Sylvie

2013-01-01

245

Heavy Metals Levels in Soil and Vegetables in Different Growing Systems  

Directory of Open Access Journals (Sweden)

Full Text Available The current project deals with an issue of actuality and scientific/technical necessity and aims to assess the factors contributing to the vulnerability of ecological systems and therefore endangering/compromising food safety. The goals of this ongoing study are to address the main risk factors on ecological system with particular regards to fresh growing vegetables and to establish technical monitoring system(s with a view to increase food safety. Herein, the authors present the research results obtained in 2011 in SIECOLEG Project regarding the assessment of some heavy metals (mainly lead, cadmium, cooper, and manganese of 80 samples soils and 25 samples vegetables from some ecological system. The concentrations of heavy metals were measured by Atomic absorption spectrometer (AAS Schimadzu 6300 - with graphite furnace atomizer and autosampler. In soil: lead and cadmium concentrations ranged from 4.51 to 6.58 mg/kg and from 0.14 to 0.4 mg/kg, respectively. Cooper and manganese concentrations ranged from 20.73 to 6.58 mg/kg and from 218.1 to 298.3 mg/kg, respectively. In vegetables (tomatoes, cucumber, peppers, eggplant, cabbage: lead concentrations ranged from 0.0 (tomatoes to 4.35 mg/kg (cabbage; cooper concentrations ranged from 0.2 mg/kg (cucumber to 0.80 mg/kg (eggplant; manganese concentrations ranged from 0.0 mg/kg (tomatoes to 0.60 mg/kg (eggplant. Cadmium was not detected in any of analysed vegetable samples. Under these circumstances, the project intends to demonstrate the extent of this vulnerability and to elaborate measures for controlling and diminishing the effects of the involved factors in order to increase food safety and security for ecological fresh vegetables

Hura C.

2013-04-01

246

Caracterización del efecto de estrés usando índices espectrales de la vegetación para la estimación de variables relacionadas con la biomasa del área / Characterization of stress effect using spectral vegetation indexes for the estimate of variables related to aerial biomass  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El uso de índices espectrales o IV de la vegetación, basados en las líneas iso-IAF en el espacio espectral del rojo (R) e infrarrojo cercano (IRC), plantea relaciones diferentes en las etapas vegetativas y de senescencia con variables biofísicas como la biomasa aérea o Bm, el índice de área foliar o [...] IAF o la cobertura aérea de la vegetación o fv. Con el índice FVIS basado en las líneas iso-suelo del espacio R-IRC, los patrones temporales pueden identificarse mediante un modelo expo-lineal y exponencial. Así, las pendientes para la etapa vegetativa y de senescencia pueden usarse para cuantificar el nivel de estrés utilizando el concepto de equivalencia ambiental. Este esquema de caracterización fue analizado con mediciones radiométricas y de fv en cultivos de fríjol (Phaseolus vulgaris L.), garbanzo (Cicer arietinum L.), cártamo (Carthamus tinctorius, L.), sorgo (Sorghum bicolor, L. Moench) y trigo (Triticum spec. L.), del Valle del Yaqui, estado de Sonora, México. Los resultados obtenidos soportan la aproximación de caracterización planteada para el nivel de estrés. Abstract in english The use of spectral indexes or vegetation VI, based on iso-LAI lines in the spectral space of red (R) and near infrared (NIR), presents different relations in vegetative and senescence periods with biophysical variables such as aerial biomass or Bm, the index of foliar area or LAI, or aerial vegetat [...] ion cover or fv. With the ISVI index based on iso-soil lines of the R-NIR space, the temporal patterns may be identified by an expo-linear and exponential model. Thus, the slopes for the vegetative phase and for senescence can be used to quantify the stress level utilizing the concept of environmental equivalence. This scheme of characterization was analyzed with radiometric and fv measurements in crops of bean (Phaseolus vulgaris L.), chickpea (Cicer arietinum. L.), safflower (Carthamus tinctorius L.), sorghum (Sorghum bicolor, L. Moench), and wheat (Triticum spec. L.) of the Valle del Yaqui, State of Sonora, México. The obtained results support the approximation of the characterization proposed for the stress level.

Marisol, Reyes; Fernando, Paz; Marcos, Casiano; Fermín, Pascual; M. Isabel, Marín; Enrique, Rubiños.

2011-03-01

247

Toward Estimating Wetland Water Level Changes Based on Hydrological Sensitivity Analysis of PALSAR Backscattering Coefficients over Different Vegetation Fields  

Directory of Open Access Journals (Sweden)

Full Text Available Synthetic Aperture Radar (SAR has been successfully used to map wetland’s inundation extents and types of vegetation based on the fact that the SAR backscatter signal from the wetland is mainly controlled by the wetland vegetation type and water level changes. This study describes the relation between L-band PALSAR  and seasonal water level changes obtained from Envisat altimetry over the island of Île Mbamou in the Congo Basin where two distinctly different vegetation types are found. We found positive correlations between and water level changes over the forested southern Île Mbamou whereas both positive and negative correlations were observed over the non-forested northern Île Mbamou depending on the amount of water level increase. Based on the analysis of sensitivity, we found that denser vegetation canopy leads to less sensitive  variation with respect to the water level changes regardless of forested or non-forested canopy. Furthermore, we attempted to estimate water level changes which were then compared with the Envisat altimetry and InSAR results. Our results demonstrated a potential to generate two-dimensional maps of water level changes over the wetlands, and thus may have substantial synergy with the planned Surface Water and Ocean Topography (SWOT mission.

Ting Yuan

2015-03-01

248

The role of vegetated areas on fish assemblage of the Paraná River floodplain: effects of different hydrological conditions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste artigo analisamos as mudanças na composição e abundância das assembléias de peixes de sete áreas úmidas de planície de inundação com vegetação e com diferentes conectividades e em diferentes condições hidrológicas: depois de uma conexão prolongada da planície de inundação com o canal principal [...] , durante o recuo das águas e após um isolamento prolongado. Nós também investigamos o tamanho e abundância das espécies migratórias de grande tamanho encontradas nestas áreas úmidas e os recursos alimentares explorados pelas espécies dominantes. Os peixes foram capturados com rede durante o dia (8.0 m x 1.50 m, malha de 5 mm) nos bancos de macrófitas. Apesar do alto número de espécies registradas (100), a riqueza de espécies nas amostras variou entre 7 e 31, de acordo com o local e data de coleta. A análise de cluster indicou uma baixa similaridade entre os locais tanto durante o período de isolamento como no de conexão prolongada. A substituição de espécies decresceu do período de cheia (? = 40.33) a vazante (? = 33.83), com o valor mínimo de índice de diversidade beta obtido durante o isolamento das áreas úmidas da planície de inundação (? = 26.83). Os resultados indicaram que diferentes populações dominantes de peixes ocorrem em condições hidrológicas diferentes, mesmo quando fases de cheia e de isolamento ocorreram na mesma estação em anos diferentes. A ordenação (NMDS) indicou a importância das condições hidrológicas na estruturação das assembléias de peixes na planície de inundação estudada. Caracídeos de pequeno tamanho, tipicamente associados à macrófitas, dominaram a assembléia de peixes, enquanto que indivíduos jovens de espécies de maior porte e migratórias foram encontradas em baixa abundância. O comprimento padrão máximo dos peixes capturados foi de 28 cm; para espécies migratórias de maior porte o comprimento padrão variou de 1,6 a 25 cm. Os peixes dominantes utilizaram vários recursos alimentares, mas organismos associados às macrófitas litorâneas apresentaram uma alta frequência de ocorrência nas três condições hidrológicas. A alta riqueza de espécies de peixes nos pequenos lagos com vegetação foi relacionado à alta heterogeneidade espacial durante as diferentes condições hidrológicas. Distúrbios nos pulsos hidrológicos podem reduzir a biodiversidade pela modificação da conectividade da área de inundação com o canal principal do rio. A conservação das áreas úmidas com vegetação requer a manutenção da variação de conectividade a fim de proporcionar a diversidade de habitats ao longo do tempo. Abstract in english In this paper, we analyze the changes in composition and abundance of fish assemblages in seven vegetated floodplain wetlands with different connectivity across different hydrologic conditions: after a prolonged connection of the floodplain with the main channel, during receding water, and after a p [...] rolonged isolation. We also investigated the size and abundance of large-sized migratory species found in these wetlands and the food resources exploited by the dominant fish. Fishes were captured by diurnal seining (8.0 m x 1.50 m, 5 mm mesh) along macrophyte banks. Despite the high total number of species registered (100), sample species richness varied between 7 and 31, depending on the sampling site and the sampling date. Cluster analysis indicated low similarity between sites during both the isolation and the prolonged connection. Species turnover decreased from high water (? = 40.33) to low water (? = 33.83), with the minimum value of beta diversity index obtained during the isolation of the floodplain wetlands (? = 26.83). Our results indicated that different dominant populations of fish occur in different hydrological conditions, even though high water and isolation phases occur in the same season of different years. The ordination (NMDS) indicated the importance of hydrologic conditions in stru

Juan José, Neiff; Alicia Poi de, Neiff; Marta B. Canón, Verón.

2009-03-01

249

Bacterial diversity in the saliva of patients with different oral hygiene indexes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo do presente estudo foi avaliar a diversidade bacteriana da saliva de pacientes com diferentes índices de higiene bucal através da construção de duas bibliotecas do gene 16S rRNA. Cada biblioteca foi composta por amostras de saliva de pacientes com índice de biofilme dental de Silness-Löe [...] diferenciado, sendo a primeira (A) com índice de 1,0 a 3,0 (denominada de alto índice) e a segunda (B), entre 0 a 0,5 (denominada de baixo índice). O DNA da saliva foi extraído e o gene 16S rRNA foi amplificado, clonado e sequenciado. As sequências obtidas foram comparadas com aquelas armazenadas no GenBank do NCBI e RDP. A saliva de pacientes com alto índice de biofilme dental apresentou cinco gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella e Peptostreptococcus e 33,3% de bactérias não-cultivadas, agrupados em 23 unidades taxonômicas operacionais (UTOs). A saliva de pacientes com baixo índice de biofilme dental, foi diferente significativamente da primeira (p=0,000) e foi composta de 42 UTOs, distribuídas em 11 gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces, além de 24,87% de bactérias não-cultivadas. Pode-se concluir que existe maior diversidade bacteriana na saliva de pacientes com baixo índice de biofilme dental em relação a pacientes com alto índice de biofilme dental Abstract in english The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: t [...] he first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

Juliana Vianna, Pereira; Luciana, Leomil; Fabíola, Rodrigues-Albuquerque; José Odair, Pereira; Spartaco, Astolfi-Filho.

250

The values of ED50 and therapeutic indexes of different radioprotector groups  

International Nuclear Information System (INIS)

Radioprotective agents were shown to be divided in 3 groups: (1) cystamine, AET, cystaphos, gammaphos, and thiogammaphos with ED50 (the dose that gave a half of the maximal protective effect) of 103-101,6 ?mol/kg and therapeutic index K LD50/ED50 = 100-101,6; (2) 5-methoxythyptamine, phenylephrine, serotonine, and norepinephrine with ED50 101-100 ?mol/kg and K = 101,8-102,6; (3) clonidine and isoprenaline with ED50 = 10-0,5-10-0,8 ?mol/kg and K = 103-104. Possible causes of these differences and advantages of low ED50 and high K were discussed

251

Swift and heavy ion implanted chalcogenide laser glass waveguides and their different refractive index distributions.  

Science.gov (United States)

Planar waveguides have been fabricated in Nd- or Ho-doped gallium lanthanum sulfide laser glasses by 60?MeV Ar or 20?MeV N ion implantation. The refractive index profiles were reconstructed based on the results of prism coupling. The Ar implanted waveguides exhibit an approximate steplike distribution, while the N implanted ones show a "well + barrier" type. This difference can be attributed to the much lower dose of Ar ions. After annealing, the N implanted waveguides can support two modes at 1539?nm and have low propagation loss, which makes them candidates for novel waveguide lasers. PMID:21343996

Qiu, Feng; Narusawa, Tadashi; Zheng, Jie

2011-02-10

252

Swift and heavy ion implanted chalcogenide laser glass waveguides and their different refractive index distributions  

International Nuclear Information System (INIS)

Planar waveguides have been fabricated in Nd- or Ho-doped gallium lanthanum sulfide laser glasses by 60 MeV Ar or 20 MeV N ion implantation. The refractive index profiles were reconstructed based on the results of prism coupling. The Ar implanted waveguides exhibit an approximate steplike distribution, while the N implanted ones show a ''well + barrier'' type. This difference can be attributed to the much lower dose of Ar ions. After annealing, the N implanted waveguides can support two modes at 1539 nm and have low propagation loss, which makes them candidates for novel waveguide lasers.

253

Swift and heavy ion implanted chalcogenide laser glass waveguides and their different refractive index distributions  

Energy Technology Data Exchange (ETDEWEB)

Planar waveguides have been fabricated in Nd- or Ho-doped gallium lanthanum sulfide laser glasses by 60 MeV Ar or 20 MeV N ion implantation. The refractive index profiles were reconstructed based on the results of prism coupling. The Ar implanted waveguides exhibit an approximate steplike distribution, while the N implanted ones show a ''well + barrier'' type. This difference can be attributed to the much lower dose of Ar ions. After annealing, the N implanted waveguides can support two modes at 1539 nm and have low propagation loss, which makes them candidates for novel waveguide lasers.

Qiu Feng; Narusawa, Tadashi; Zheng Jie

2011-02-10

254

The Millon Index of Personality Styles Revised (MIPS-R) in Portugal: Gender Differences  

OpenAIRE

This study aims to determine whether males and females differ in the personality styles mesured with the Portuguese version of the Millon Index of Personality Styles Revised, MIPS-R (Millon, 2004). The MIPS-R is a 180-item, True/False inventory designed to measure personality styles of normally functioning adults between the ages of 18 and 65+. It is a theory-based inventory, grounded in biosocial and evolutionary theory, and comprises 12 pairs of scales organized into three main areas: Motiv...

Pires, Rute; Fagulha, Teresa; Silva, Danilo R.

2007-01-01

255

Heavy Metals Levels in Soil and Vegetables in Different Growing Systems  

OpenAIRE

The current project deals with an issue of actuality and scientific/technical necessity and aims to assess the factors contributing to the vulnerability of ecological systems and therefore endangering/compromising food safety. The goals of this ongoing study are to address the main risk factors on ecological system with particular regards to fresh growing vegetables and to establish technical monitoring system(s) with a view to increase food safety. Herein, the authors present the research re...

Hura C.; Munteanu N.; Stoleru V.

2013-01-01

256

Light sharing among different forest strata for sustainable management of vegetation and regeneration  

OpenAIRE

There is a current trend towards managing forests with multiple objectives, in particular to preserve or increase biodiversity and sustainability. There is renewed interest in understorey vegetation as a way both to increase the number of species and, indirectly, to favour fauna, including game, or improve soil quality. However, this stratum of herbaceous or shrubby species can also compete with young tree seedling and jeopardise tree regeneration. Hence a compromise has to be found among the...

Balandier, P.; Marquier, A.; Dumas, Y.; Gaudio, N.; Philippe, G.; Da Silva, D.; Adam, B.; Ginisty, C.; Sinoquet, H.

2009-01-01

257

Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables  

OpenAIRE

In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found ...

Koci?-Tanackov Sun?ica D.; Dimi? Gordana R.; Levi? Jelena T.; Pejin Dušanka J.; Pejin Jelena D.; Jaji? Igor M.

2010-01-01

258

Development of a remotely sensing seasonal vegetation-based Palmer Drought Severity Index and its application of global drought monitoring over 1982-2011  

Science.gov (United States)

Vegetation effects are currently disregarded in Palmer Drought Severity Index (PDSI), and the sensitivity of PDSI to the choice of potential evaporation (EP) parameterization is often a concern. We developed a revised self-calibrating PDSI model that replaces EP with leaf area index-based total evapotranspiration (ARTS E0). It also included a simple snowmelt module. Using a unique satellite leaf area index data set and climate data, we calculated and compared ARTS E0, three other types of EP (i.e., Thornthwaite EP_Th, Allen EP_Al, and Penman-Monteith EP_PM), and corresponding PDSI values (i.e., PDSI_ARTS, PDSI_Th, PDSI_Al, and PDSI_PM) for the period 1982-2011. The results of PDSI_ARTS, PDSI_Al, and PDSI_PM show that global land became wetter mainly due to increased precipitation and El Niño-Southern Oscillation (ENSO) effect for the period, which confirms the ongoing intensification of global hydrologic cycle with global temperature increase. However, only PDSI_Th gave a trend of global drying, which confirms that PDSI_Th overestimates the global drying in response to global warming; i.e., PDSI values are sensitive to the parameterizations for Ep. Thus, ARTS E0, EP_Al, and EP_PM are preferred to EP_Th in global drought monitoring. In short, global warming affects global drought condition in two opposite ways. One is to contribute to the increases of EP and hence drought; the other is to increase global precipitation that contributes to global wetting. These results suggest that precipitation trend and its interaction with global warming and ENSO should be given much attention to correctly quantify past and future trends of drought.

Yan, Hao; Wang, Shao-Qiang; Lu, Hou-Quan; Yu, Qin; Zhu, Zai-Chun; Myneni, Ranga B.; Liu, Qiang; Shugart, Herman H.

2014-08-01

259

Relationships between vegetation indices and different burn and vegetation ratios: a multi-scale approach applied in a fire affected area  

Science.gov (United States)

Vegetation indices have been widely used in remote sensing literature for burned land mapping and monitoring. In the present study we used satellite data (IKONOS, LANDSAT, ASTER, MODIS) of multiple spectral (visible, near, shortwave infrared) and spatial (1-500 meters) resolutions, acquired shortly after a very destructive fire occurred in the mountain of Parnitha in Attica, Greece the summer of 2007. The aim of our study is to examine and evaluate the performance of some vegetation indices for burned land mapping and also to characterize the relationships between vegetation indices and the percent of fire-scorched (burned) and non fire-scorched (vegetated) areas. The available satellite images were processed geometrically, radiometrically and atmospherically. The very high resolution IKONOS imagery was served as a base to estimate the percent of cover of burned areas, bare soil and vegetation by applying the maximum likelihood classification algorithm. The percent of cover for each type was then correlated to vegetation indices for all the satellite images, and regression models were fit to characterize those relationships. In total 57 versions of some classical vegetation indices were computed using LANDSAT, ASTER and MODIS data. Most of them were modified by replacing Red with SWIR channel, as the latter has been proved sensitive to burned area discrimination. IPVI and NDVI showed a better performance among the indices tested to estimate the percent of vegetation, while most of the modified versions of the indices showed highest performance to estimate the percent of burned areas.

Pleniou, M.; Koutsias, N.

2013-08-01

260

The relationship between phytomass, NDVI and vegetation communities on Svalbard  

Science.gov (United States)

Several studies have shown a close relationship between vegetation fertility and different vegetation indices extracted from satellite data. The vegetation fertility in Arctic is at overall scales highly related to temperature. At lower scales surface material, snow cover, hydrology and anthropogenic effects (geese, reindeer) are determinant in constituting the different vegetation communities. The extent and occurrence of different vegetation communities are expressed in vegetation maps. On Svalbard a vegetation map covering the entire archipelago has recently been developed. The map is differentiated into 18 map units showing large areas of non- and sparsely vegetated ground. The most favorable vegetation is seen as productive marshes and moss tundra communities in the lowland. Various mathematical combinations of spectral channels in satellite images have been applied as sensitive indicators of the presence and condition of green vegetation. Today the normalized difference vegetation index (NDVI) is mostly used to display this information. NDVI is an indicator of the density of chlorophyll in leaf tissue calculated from the red and near infrared bands: NDVI = (NIR - RED)/(NIR + RED). NDVI gives values between -1 and +1 where vegetated areas in general yield high positive values, while non-vegetated ground is found on the negative side.

Johansen, Bernt; Tømmervik, Hans

2014-04-01

261

On the calculation of the topographic wetness index: evaluation of different methods based on field observations  

Directory of Open Access Journals (Sweden)

Full Text Available The topographic wetness index (TWI, ln(a/tan?, which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwater level, soil moisture, and a constructed wetness degree. The TWI was calculated by varying six parameters affecting the distribution of accumulated area among downslope cells and by varying the way the slope was calculated. All possible combinations of these parameters were calculated for two separate boreal forest sites in northern Sweden. We did not find a calculation method that performed best for all measured variables; rather the best methods seemed to be variable and site specific. However, we were able to identify some general characteristics of the best methods for different groups of measured variables. The results provide guiding principles for choosing the best method for estimating species richness, soil pH, groundwater level, and soil moisture by the TWI derived from digital elevation models.

R. Sørensen

2006-01-01

262

Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.  

Energy Technology Data Exchange (ETDEWEB)

A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4

Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

2005-05-01

263

EMG parameters and EEG ? Index change at fatigue period during different types of muscle contraction  

Science.gov (United States)

The purpose of this study is to measure and analyze the characteristics in change of EMG and EEG parameters at muscle fatigue period in participants with different exercise capacity. Twenty participants took part in the tests. They were divided into two groups, Group A (constant exerciser) and Group B (seldom-exerciser). MVC dynamic and 1/3 isometric exercises were performed; EMG and EEG signals were recorded synchronously during different type of muscle contraction. Results indicated that values of MVC, RMS and IEMG in Group A were greater than Group B, but isometric exercise time was shorter than the time of dynamic exercise although its intensity was light. Turning point of IEMG and ? Index occurred synchronously during constant muscle contraction of isometric or dynamic exercise. It is concluded that IEMG turning point may be an indication to justify muscle fatigue. Synchronization of EEG and EMG reflects its common characteristics on its bio-electric change.

Zhang, Li; Zhou, Bin; Song, Gaoqing

2011-03-01

264

Influence of Paclobutrazol and Ethephon on Vegetative Growth of Guava (Psidium guajava L. Plants at Different Spacing  

Directory of Open Access Journals (Sweden)

Full Text Available To ascertain the growth retarding potential of Paclobutrazol (PBZ and Ethephon on guava plants at different spacing viz 6?2 m, 6?3 m, 6?4 m and 6?5 m; both were applied at 500 ppm, 1000 ppm as a foliar spray. Investigation revealed that all treatments influence the vegetative growth of plants compared to untreated plants at all spacing levels. However, paclobutrazol considerably restrict the overall vegetative growth of trees. Stock and scion girth was found to be increased with ethephon treatments. The tree height and E-W tree spread was found to increased with increasing plant density. Similarly, trunk girth in terms of stock and scion girth was also increased with increase in plant spacing. Although, the PBZ 500 ppm markedly restrict the plant growth but it may be further investigated for managing the guava tree canopies under high density planting systems, taking the fruit quality and economic aspects into consideration.

Jaswinder Singh BRAR

2010-09-01

265

Monitoring Vegetation Phenological Cycles in Two Different Semi-Arid Environmental Settings Using a Ground-Based NDVI System: A Potential Approach to Improve Satellite Data Interpretation  

Directory of Open Access Journals (Sweden)

Full Text Available In semi-arid environmental settings with sparse canopy covers, obtaining remotely sensed information on soil and vegetative growth characteristics at finer spatial and temporal scales than most satellite platforms is crucial for validating and interpreting satellite data sets. In this study, we used a ground-based NDVI system to provide continuous time series analysis of individual shrub species and soil surface characteristics in two different semi-arid environmental settings located in the Great Basin (NV, USA. The NDVI system was a dual channel SKR-1800 radiometer that simultaneously measured incident solar radiation and upward reflectance in two broadband red and near-infrared channels comparable to Landsat-5 TM band 3 and band 4, respectively. The two study sites identified as Spring Valley 1 site (SV1 and Snake Valley 1 site (SNK1 were chosen for having different species composition, soil texture and percent canopy cover. NDVI time-series of greasewood (Sarcobatus vermiculatus from the SV1 site allowed for clear distinction between the main phenological stages of the entire growing season during the period from January to November, 2007. NDVI time series values were significantly different between sagebrush (Artemisia tridentata and rabbitbrush (Chrysothamnus viscidiflorus at SV1 as well as between the two bare soil types at the two sites. Greasewood NDVI from the SNK1 site produced significant correlations with chlorophyll index (r = 0.97, leaf area index (r = 0.98 and leaf xylem water potential (r = 0.93. Whereas greasewood NDVI from the SV1 site produced lower correlations (r = 0.89, r = 0.73, or non significant correlations (r = 0.32 with the same parameters, respectively. Total percent cover was estimated at 17.5% for SV1 and at 63% for SNK1. Results from this study indicated the potential capabilities of using this ground-based NDVI system to extract spatial and temporal details of soil and vegetation optical properties not possible with satellite derived NDVI.

Malika Baghzouz

2010-04-01

266

A systematic review of socio-economic differences in food habits in Europe: consumption of fruit and vegetables  

DEFF Research Database (Denmark)

Objective: To evaluate the differences in the consumption of fruit and vegetables between groups with different socio-economic status (SES) in the adult population of European countries. Design: A systematic review of published and unpublished surveys of food habits conducted between 1985 and 1999 in 15 European countries. Educational level and occupational status were used as indicators of SES. a pooled estimate of the mean difference between the highest and the lowest level of education and occupation was calculated separately for men and women, using DerSimonian and Laird's random effects model. Setting: The inclusion criteria of studies were: use of a validated method for assessing intake at the individual level; selection of a nationwide sample or a representative sample of a region; and providing the mean and standard deviation of overall fruit and vegetable consumption for each level of education or occupation, and separately for men and women. Subjects: Participants in the individual surveys had to be adults (18 - 85 y). Results: Eleven studies from seven countries met the criteria for being included in the meta-analysis. A higher SES was associated with a greater consumption of both fruit and vegetables. The pooled estimate of the difference in the intake of fruit was 24.3 g/person/day (95% confidence interval (CI) 14.0-34.7) between men in the highest level of education and those in the lowest level of education. Similarly, this difference was 33.6g/person/day for women (95% CI 22.5-44.8). The differences regarding vegetables were 17.0g/person/day (95% CI 8.6-25.5) for men and 13.4g/person/day (95% CI 7.1-19.7) for women. The results were in the same direction when occupation instead of education was used as an indicator of SES. Conclusions: Although we cannot exclude over-reporting of intake by those with highest SES, it is unlikely that this potential bias could fully explain the differences we have found. Our results suggest that an unhealthier nutrition pattern may exist among adults belonging to lower socio-economic levels in Europe.

Irala-Estevez, J. De; Groth, Margit Velsing

2000-01-01

267

An orbital-based density difference index for the comparison of electron density distributions  

Science.gov (United States)

A new semiquantitative measure of the difference between two electron density distributions is proposed. Specifically, the natural orbitals of an accurate electron density, such as those given by a configuration interaction method, are used to expand the Kohn-Sham orbitals of an approximate density functional method. The difference between the two density distributions is then reduced to a single number, the orbital-based density difference index (DDI). With the reference densities calculated from quadratic configuration interaction calculations including single and double substitutions, DDIs were obtained for four diatomic molecules using three basis sets and seven approximate functionals. Results are also included for an additional six small molecules with a flexible extended basis set and the same set of functionals. These results show that the DDI leads to conclusions that are consistent with those obtained previously by visual comparison of density difference plots. The orbital-based density difference indices are very dependent on the choice of the functional, but are fairly stable with respect to the choice of the basis set.

Worsnop, S. Kent; Wang, Jiahu; Boyd, Russell J.

1997-11-01

268

Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia  

Science.gov (United States)

Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating the model results, and (iii) the methods used to compare simulated and observed vegetation. We use vegetation simulated for Asia by the equilibrium vegetation model BIOME4 as a typical example of vegetation model output. BIOME4 was run using 19 different climatologies and their associated atmospheric CO2 concentrations. The Kappa statistic, Fuzzy Kappa statistic and a newly developed map-comparison method, the Nomad index, were used to quantify the agreement between the biomes simulated under each scenario and the observed vegetation from three different global land- and tree-cover data sets: the global Potential Natural Vegetation data set (PNV), the Global Land Cover Characteristics data set (GLCC), and the Global Land Cover Facility data set (GLCF). The results indicate that the 30-year mean climatology (and its associated atmospheric CO2 concentration) for the time period immediately preceding the collection date of the observed vegetation data produce the most accurate vegetation simulations when compared with all three observed vegetation data sets. The study also indicates that the BIOME4-simulated vegetation for Asia more closely matches the PNV data than the other two observed vegetation data sets. Given the same observed data, the accuracy assessments of the BIOME4 simulations made using the Kappa, Fuzzy Kappa and Nomad index map-comparison methods agree well when the compared vegetation types consist of a large number of spatially continuous grid cells. The results of this analysis can assist model users in designing experimental protocols for simulating vegetation.

Tang, Guoping; Shafer, Sarah L.; Barlein, Patrick J.; Holman, Justin O.

2009-01-01

269

Development and testing of an index of biotic integrity based on submersed and floating vegetation and its application to assess reclamation wetlands in Alberta's oil sands area, Canada.  

Science.gov (United States)

We developed and tested a plant-based index of biological integrity (IBI) and used it to evaluate the existing reclamation wetlands in Alberta's oil sands mining region. Reclamation plans call for >15,000 ha of wetlands to be constructed, but currently, only about 25 wetlands are of suitable age for evaluation. Reclamation wetlands are typically of the shallow open water type and range from fresh to sub-saline. Tailings-contaminated wetlands in particular may have problems with hydrocarbon- and salt-related toxicity. From 60 initial candidate metrics in the submersed aquatic and floating vegetation communities, we selected five to quantify biological integrity. The IBI included two diversity-based metrics: the species richness of floating vegetation and the percent of total richness contributed by Potamogeton spp. It also included three relative abundance-based metrics: that of Ceratophyllum demersum, of floating leafed species and of alkali-tolerant species. We evaluated the contribution of nonlinear metrics to IBI performance but concluded that the correlation between IBI scores and wetland condition was not improved. The method used to score metrics had an influence on the IBI sensitivity. We conclude that continuous scoring relative to the distribution of values found in reference sites was superior. This scoring approach provided good sensitivity and resolution and was grounded in reference condition theory. Based on these IBI scores, both tailings-contaminated and tailings-free reclamation wetlands have significantly lower average biological integrity than reference wetlands (ANOVA: F(2,59) = 34.7, p = 0.000000000107). PMID:21484300

Rooney, Rebecca C; Bayley, Suzanne E

2012-01-01

270

Adherence to a vegetable-fruit-soy dietary pattern or the Alternative Healthy Eating Index is associated with lower hip fracture risk among Singapore Chinese.  

Science.gov (United States)

Data on overall dietary pattern and osteoporotic fracture risk from population-based cohorts are limited, especially from Asian populations. This study examined the relation between overall diet and hip fracture risk by using principal components analysis (PCA) to identify dietary pattern specific to the study population and by using the Alternative Healthy Eating Index (AHEI) 2010 to assess dietary quality. The Singapore Chinese Health Study is a prospective population-based cohort that enrolled 63,257 Chinese men and women (including both pre- and postmenopausal women) aged 45-74 y between 1993 and 1998 in Singapore. Habitual diet was assessed by using a validated food-frequency questionnaire. Two dietary patterns, the vegetable-fruit-soy (VFS) pattern and the meat-dim-sum (MDS) pattern, were derived by PCA. Overall dietary quality was assessed according to the AHEI 2010, which was defined a priori for chronic disease prevention. A Cox regression model was applied with adjustment for potential confounders. In both genders, higher scores for the VFS pattern and the AHEI 2010 were associated with lower risk of hip fracture in a dose-dependent manner (all P-trend ? 0.008). Compared with the lowest quintile, participants in the highest quintile had a 34% reduction in risk (HR: 0.66; 95% CI: 0.55, 0.78) for the VFS pattern and a 32% reduction in risk (HR: 0.68; 95% CI: 0.58, 0.79) for the AHEI 2010. The MDS pattern score was not associated with hip fracture risk. An Asian diet rich in plant-based foods, namely vegetables, fruit, and legumes such as soy, may reduce the risk of hip fracture. PMID:24572035

Dai, Zhaoli; Butler, Lesley M; van Dam, Rob M; Ang, Li-Wei; Yuan, Jian-Min; Koh, Woon-Puay

2014-04-01

271

Correlação espacial do índice de vegetação (NDVI) de imagem Landsat/ETM+ com atributos do solo / Spatial correlation of the vegetation index (NDVI) of a Landsat/ETM+ images with soil attributes  

Scientific Electronic Library Online (English)

Full Text Available As tecnologias de agricultura de precisão, como o uso da variabilidade espacial dos atributos do solo, vêm sendo muito estudadas para a cultura de cana-de-açúcar. Dentre essas tecnologias se destaca o uso de índices de vegetação derivados de produtos de sensoriamento remoto, como poderosas ferrament [...] as indicadoras do desenvolvimento da vegetação. Objetivou-se, neste estudo, analisar a variabilidade espacial dos teores de argila, fósforo e o pH de um Latossolo Vermelho-amarelo em área com produção de cana-de-açúcar e correlacioná-los com o índice espectral de vegetação (NDVI). Foram estudados, a partir de uma malha georreferenciada, os atributos do solo (argila, fósforo e pH) e gerados mapas de variabilidade espacial. Para esses mesmos locais calculou-se o NDVI possibilitando, além do mapeamento deste índice, a avaliação da correlação espacial entre este e as demais propriedades em estudo. A argila e o teor de fósforo apresentaram correlação espacial positiva com o NDVI enquanto nenhuma correlação espacial foi observada com o pH. A imagem do sensor ETM+ do satélite Landsat 5 utilizada neste estudo em relação ao NDVI, apresentou boa aplicação para observar a variabilidade espacial dos atributos estudados. Abstract in english The precision agriculture technologies such as the spatial variability of soil attributes have been widely studied mostly with sugarcane. Among these technologies have been recently highlighted the use of the vegetation index derived from remote sensing products, such as powerful tools indicating th [...] e development of vegetation. This study aimed to analyze the spatial variability of clay content, pH and phosphorus in an Oxisol in an area with sugarcane production, and correlate with the Normalized Difference Vegetation Index (NDVI). The georeferenced grid was created for the soil properties (clay, phosphorus and pH) and generated the maps of spatial variability. For these same sites were calculated the NDVI, in addition to mapping of this ratio, the evaluation of the spatial correlation between this and other studied properties. The clay and phosphorus content showed positive spatial correlation with the NDVI, while no spatial correlation was observed between NDVI and pH. The satellite images from the sensor ETM + Landsat were used to correlate to NDVI to observe the spatial variability of the studied attributes.

Fabricio V., Zanzarini; Teresa C. T., Pissarra; Flavia J. C., Brandão; Daniel D. B., Teixeira.

2013-06-01

272

Influence of different solvents in extraction of phenolic compounds from vegetable residues and their evaluation as natural sources of antioxidants.  

Science.gov (United States)

Dried residues from four different vegetables, viz. pea pod (pp), cauliflower waste (CW), potato peel (PP) and tomato peel (TP) were extracted using four solvents i.e., hexane, chloroform, ethyl acetate and methanol. Among the four solvents, methanolic extracts showed the highest total phenolic content (TPC) for all the four vegetable residues. Methanolic extracts were evaluated for antioxidant activities using diphenylpicryl-hydrazyl (DPPH) and reducing power assay. Tomato peel extract showed highest phenolic content of 21.0 mg GAE/g-dw and 80.8 % DPPH free radical scavenging ability, whereas potato peel extract had a low phenolic content, and it also showed the least antioxidant activity among the residues examined in this study. Total phenolic content and DPPH free radical scavenging activity in pea pods and cauliflower waste were 13.6 mg GAE/g-dw and 72 % and 9.2 mg GAE/g-dw and 70.7 %, respectively. The coefficient of determination (r(2)) for correlation between TPC and reducing power, DPPH and TPC, DPPH and reducing power for all extracts was 0.85, 0.91and 0.87, respectively, suggesting an important role of phenolics in imparting antioxidant ability. Extracts from vegetables residues therefore represent a significant source of phenolic antioxidants for use as nutraceuticals or biopreservatives. PMID:25328197

Babbar, Neha; Oberoi, Harinder Singh; Sandhu, Simranjeet Kaur; Bhargav, Vinod Kumar

2014-10-01

273

Feed intake and activity level of two broiler genotypes foraging different types of vegetation in the finishing period  

DEFF Research Database (Denmark)

A study was performed with 2 broiler genotypes (slow and medium growth) restricted in supplementary feed and foraging 2 different mixed vegetations (grass/clover or chicory) to identify possible benefits of herbage on nutrition during the finishing period (80 to 113 d of age). Three hundred birds were included in a 2 × 2 factorial design with groups of 25 birds replicated 3 times. The use of outdoor areas, performance, and forage intake were investigated. To identify possible differences in foraging activity, the use of the range was monitored one day per week at 4 different times of the day. Feed intake from foraging was estimated by killing 4 birds per plot (2 males and 2 females) in the morning and in the evening on 3 d during the experiment and measuring crop content. Vegetation type did not influence broiler use of the free-range area, feed intake, or performance. Differences in the use of the range area, activity level, and feed content in the crops were observed in relation to genotype, sex, age of broilers, and also the time of day. Foraging activity was positively correlated with age. Medium-growth broilers spent more time inside and closer to the broiler houses during the day with increased foraging activity during evenings, in contrast to the slow-growing broilers that showed a more uniform activity during the day. Based on the measurement of crop content it was estimated that the slow-growing genotype had a daily intake of 5 to 8 g of forage per day, whereas the medium-growing genotype had an intake of 9 g for females and 20 g for males. In conclusion, limitation of supplemented protein feed in the finishing period may be acceptable for broilers that have access to highly nutritious vegetation.

Almeida, Gustavo Fonseca; Hinrichsen, Lena Karina

2012-01-01

274

Vegetative and reproductive development of different avocado selections Co60 irradiated  

International Nuclear Information System (INIS)

Data of vegetative and reproductive behavior were registered of 2 cultivars and 5 selections avocado trees which survived 2.0 krad irradiation dosage these trees are in their third year of development. Decreases in graft height were found this decrease were more evident in selections C 137 PLS and C 39 PMe (10 and 15%, respectively), and in cultivar Colin V-33 (40%) irradiated trees of the same selections presented and increase of 100% in flower density and fruit set. Selection Colin V-101 and cv. Fuerte did not present flowering so neither fruit set. We also detected a modification in fructification normal habit of selections Colinmex and C 175 PLS since fruit arises from main stem. (Author)

275

THE EFFECT OF STORAGE TIME IN DIFFERENT TEMPERATURE ON NATIVE CHICKEN EGG HAUGH UNIT AND YOLK INDEX  

Directory of Open Access Journals (Sweden)

Full Text Available Three hundred sixty native chicken eggs was test on the effect of storage time in different temperature on haugh unit and yolk index. The aim of this research is to get the effect of storage time in different temperatures : 300 – 32oC (RH 54%, 280 – 290 C (RH 58% and 150 – 180 C (RH 80%; on native chicken eggs haugh unit and yolk index. This experiment used Completely Randomized Design (CRD on three different temperatures (30-320C, 28-290C and 15­180C and each treatment was repeated six times. Results indicated that the lowest temperature (15-180C has the highest haugh unit (89.96 and yolk index (0.45; and when the temperature raised (28-290C and 30-320C the haugh unit and yolk index was lower (72.80 and 0.29; 73.15 and 0.30 respectively.

Hendronoto Arnoldus W. Lengkey

2012-01-01

276

The Impacts of Weather and Conservation Programs on Vegetation Dynamics in China’s Loess Plateau  

OpenAIRE

We present an analysis of the impacts of weather change and large-scale vegetation conservation programs on the vegetation dynamics in China’s Loess Plateau from 2000 through 2009. We employed a multiple lines of evidence approach in which multi-scale data were used. We employed Normalized Difference Vegetation Index (NDVI) data, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) at 500 m to identify significant vegetation increases in the Loess Plateau since 2000. We fou...

Jianrong Fan; Beurs, Kirsten M.; Dong Yan

2013-01-01

277

Effects of Different Vegetation Zones on CH4 and N2O Emissions in Coastal Wetlands: A Model Case Study  

OpenAIRE

The coastal wetland ecosystems are important in the global carbon and nitrogen cycle and global climate change. For higher fragility of coastal wetlands induced by human activities, the roles of coastal wetland ecosystems in CH4 and N2O emissions are becoming more important. This study used a DNDC model to simulate current and future CH4 and N2O emissions of coastal wetlands in four sites along the latitude in China. The simulation results showed that different vegetation zones, including bar...

Yuhong Liu; Lixin Wang; Shumei Bao; Huamin Liu; Junbao Yu; Yu Wang,; Hongbo Shao; Yan Ouyang; Shuqing An

2014-01-01

278

“The Potential Pozzolanic Activity of Different Ceramic Waste Powder as Cement Mortar Component (Strength Activity Index  

Directory of Open Access Journals (Sweden)

Full Text Available Under the strong contemporary demand for modern and environmental friendly materials, natural pozzolan can be proved to be such material and several researchers have focused their research efforts in using it as a partial substitute in the manufacture of concrete and mortar. Pozzolans are divided into two categories, namely the natural and the artificial, as metakaoline and silica fume (SF. In recent years, the industry has shifted to using natural pozzolans because of their lower cost and accessibility. A pozzolan is a siliceous material that can be used as an inexpensive Substitute for cement in mortar mixtures. The objective of this experimental study was to examine the possibility of reusing ceramic materials waste from ceramic industry as partial cement replacement in mortar and concrete. The different types of ceramic waste were finely ground to specific sizes (0–45 lm, 45–75 lm and 75–150 lm from different industries and its pozzolanic activity was determined. The compressive strength activity index at 7, 28 days and accelerated curing was determined in mortars produced with each finely grounded waste ceramics and different percentages of partial cement replacement. As per Indian standard mortar bar tests on 70.6*70.6*70.6 mm3 size mortar specimens were performed and results concluded with comparison to nominal mix specimen. own text.

Jay Patel

2014-03-01

279

Geostatistical estimation of signal-to-noise ratios for spectral vegetation indices  

Science.gov (United States)

In the past 40 years, many spectral vegetation indices have been developed to quantify vegetation biophysical parameters. An ideal vegetation index should contain the maximum level of signal related to specific biophysical characteristics and the minimum level of noise such as background soil influences and atmospheric effects. However, accurate quantification of signal and noise in a vegetation index remains a challenge, because it requires a large number of field measurements or laboratory experiments. In this study, we applied a geostatistical method to estimate signal-to-noise ratio (S/N) for spectral vegetation indices. Based on the sample semivariogram of vegetation index images, we used the standardized noise to quantify the noise component of vegetation indices. In a case study in the grasslands and shrublands of the western United States, we demonstrated the geostatistical method for evaluating S/N for a series of soil-adjusted vegetation indices derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The soil-adjusted vegetation indices were found to have higher S/N values than the traditional normalized difference vegetation index (NDVI) and simple ratio (SR) in the sparsely vegetated areas. This study shows that the proposed geostatistical analysis can constitute an efficient technique for estimating signal and noise components in vegetation indices.

Ji, Lei; Zhang, Li; Rover, Jennifer; Wylie, Bruce K.; Chen, Xuexia

2014-01-01

280

Geostatistical estimation of signal-to-noise ratios for spectral vegetation indices  

Science.gov (United States)

In the past 40 years, many spectral vegetation indices have been developed to quantify vegetation biophysical parameters. An ideal vegetation index should contain the maximum level of signal related to specific biophysical characteristics and the minimum level of noise such as background soil influences and atmospheric effects. However, accurate quantification of signal and noise in a vegetation index remains a challenge, because it requires a large number of field measurements or laboratory experiments. In this study, we applied a geostatistical method to estimate signal-to-noise ratio (S/N) for spectral vegetation indices. Based on the sample semivariogram of vegetation index images, we used the standardized noise to quantify the noise component of vegetation indices. In a case study in the grasslands and shrublands of the western United States, we demonstrated the geostatistical method for evaluating S/N for a series of soil-adjusted vegetation indices derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The soil-adjusted vegetation indices were found to have higher S/N values than the traditional normalized difference vegetation index (NDVI) and simple ratio (SR) in the sparsely vegetated areas. This study shows that the proposed geostatistical analysis can constitute an efficient technique for estimating signal and noise components in vegetation indices.

Ji, Lei; Zhang, Li; Rover, Jennifer; Wylie, Bruce K.; Chen, Xuexia

2014-10-01

281

LEAF AREA INDEX (LAI) CHANGES DETECTION OF UNDERSTORY VEGETATION IN THE ALBEMARLE-PAMLICO BASIN IKONOS AND LANDSAT ETM+ SATELLITE DATA  

Science.gov (United States)

The advent of remotely sensed data from satellite platforms has enabled the research community to examine vegetative spatial distributions over regional and global scales. This assessment of ecosystem condition through the synoptic monitoring of terrestrial vegetation extent, bio...

282

Effect of Different Levels of NaCl and KCl on Growth and Some Biological Indexes of Wheat Plant  

OpenAIRE

In this study, it was aimed to determine the effects of different levels (0, 15, 30 and 60 mM) of NaCl and KCl salt on seedling growth and some biological indexes of wheat. Shoot height, stem diameter, leaves number of plant, fresh weight of shoot and dry matter weight index were investigated. The results showed that biological index of wheat decreased with increasing salt in comparison to control. The adverse affect of NaCl on wheat plant was obtained higher than that of KCl. This should car...

Sevinc Adiloglu; Aydin Adiloglu; Mine Ozkil

2007-01-01

283

Effect of Different Levels of NaCl and KCl on Growth and Some Biological Indexes of Wheat Plant  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, it was aimed to determine the effects of different levels (0, 15, 30 and 60 mM of NaCl and KCl salt on seedling growth and some biological indexes of wheat. Shoot height, stem diameter, leaves number of plant, fresh weight of shoot and dry matter weight index were investigated. The results showed that biological index of wheat decreased with increasing salt in comparison to control. The adverse affect of NaCl on wheat plant was obtained higher than that of KCl. This should carefully be considered if wheat is grown under saline soil condition.

Sevinc Adiloglu

2007-01-01

284

Dissecting the function of the different chitin synthases in vegetative growth and sexual development in Neurospora crassa.  

Science.gov (United States)

Chitin, one of the most important carbohydrates of the fungal cell wall, is synthesized by chitin synthases (CHS). Seven sequences encoding CHSs have been identified in the genome of Neurospora crassa. Previously, CHS-1, -3 and -6 were found at the Spitzenkörper(Spk) core and developing septa. We investigated the functional importance of each CHS in growth and development of N. crassa. The cellular distribution of each CHS tagged with fluorescent proteins and the impact of corresponding gene deletions on vegetative growth and sexual development were compared. CHS-2, -4, -5 and -7 were also found atthe core of theSpk andin formingseptain vegetative hyphae. As the septum ring developed, CHS-2-GFP remained at the growing edge of the septum until it localized around the septal pore. In addition, all CHSs were located in cross-walls of conidiophores. A partial co-localization of CHS-1-m and CHS-5-GFP or CHS-2-GFP occurred in the Spk and septa. Analyses of deletion mutants suggested that CHS-6 has a role primarily in hyphal extension and ascospore formation, CHS-5 in aerial hyphae, conidia and ascospore formation, CHS-3 in perithecia development and CHS-7 in all of the aforementioned. We show that chs-7/csmB fulfills a sexual function and chs-6/chsG fulfills a vegetative growth function in N. crassa but not in Aspergillus nidulans, whereas vice versa chs-2/chsA fulfills a sexual function in A. nidulans but not in N. crassa. This suggests that different classes of CHSs can fulfill distinct developmental functions in various fungi. Immunoprecipitation followed by mass spectrometry of CHS-1-GFP, CHS-4-GFP and CHS-5-GFP identified distinct putative interacting proteins for each CHS. Collectively, our results suggest that there are distinct populations of chitosomes, each carrying specific CHSs, with particular roles during different developmental stages. PMID:25596036

Fajardo-Somera, Rosa A; Jöhnk, Bastian; Bayram, Özgür; Valerius, Oliver; Braus, Gerhard H; Riquelme, Meritxell

2015-02-01

285

Assessment of Trace Gas Emissions From Wild Fires in Different Vegetation Types in Northern Ghana: Implications for Global Warming  

Directory of Open Access Journals (Sweden)

Full Text Available Biomass burning in Northern Ghana is a major cause for concern because of its potential contribution to global warming, hence climate change. This study assessed the emission of trace gases from human activities in the Guinea savanna of Northern Ghana using the guidelines of the Intergovernmental Panel on Climate Change. Carbon content of biomass was determined from four different vegetation covers in the study area; namely, widely open savanna woodland, grass/herb with scattered trees, open savanna woodland and closed savanna woodland. Under each vegetation cover, five plots (1 m x 1 m were demarcated for the estimation of above-ground biomass density. Using the combustion furnace method, emitted carbon, methane and carbon monoxide were estimated. Results showed that the emitted methane (CH4 and carbon monoxide (CO differed significantly (p<0.05 under all the vegetation types. The gases were in perfect correlation (r=1.00 with the quantity of above-ground biomass density and carbon released, with more CO being emitted. Emission of CH4 and CO per hectare of burnt area in the open savanna woodland category was the highest with 0.001719 ton and 0.045119 ton respectively. Over time, emission of these gases may increase their atmospheric concentration, causing major health problems. The contribution to global warming, thus climate change, may also become quite significant. This underscores the fact that existing flaws in the wild fire management policy of Ghana must be effectively dealt with and appropriately implemented with regular reviews to reduce the annual wild fires that are very rampant in Northern Ghana, especially during the dry season.

Nyadzi Emmanuel

2015-03-01

286

Resting-state EEG study of comatose patients: a connectivity and frequency analysis to find differences between vegetative and minimally conscious states  

OpenAIRE

The aim of this study was to look for differences in the power spectra and in EEG connectivity measures between patients in the vegetative state (VS/UWS) and patients in the minimally conscious state (MCS).

Lehembre, Re?my; Bruno, Marie-aure?lie; Vanhaudenhuyse, Audrey; Chatelle, Camille; Cologan, Victor; Leclercq, Yves; Soddu, Andrea; Macq, Benoi?t; Laureys, Steven; Noirhomme, Quentin

2012-01-01

287

Kinetics of soil enzyme activities under different ecosystems: An index of soil quality  

Scientific Electronic Library Online (English)

Full Text Available Soil microbial activity plays an important role in regulating biotransformation, nutrient cycling and hence the microbiological processes are at the center of many ecological functions. The kinetic parameters (Vmax and KmMichaelis constant) of different enzymes (amylase, invertase, protease, urease, [...] and dehydrogenase) were determined in order to assess the metabolic response of soil. The maximum reaction velocity (Vmax) represents a maximum rate of activity when all enzymes are saturated, which markedly increased in forest soil as compared to fresh mine spoil due to the gradual accumulation of soil organic matter. Smaller Km value was estimated in forest soil (FS) as compared to fresh mine spoil (FMS), suggesting the greater affinity of soil enzymes for substrate in FS. The catalytic efficiency (Vmax /Km) reflects an impression on microbial community composition with a change in soil enzymes. These enzyme characters (activities and kinetic parameters) have greater significance as early and sensitive indicators of the changes in soil properties induced by different management systems. These parameters (Vmax and Km) can be useful markers to assess changes in microbial activity of soil, since they represent quantity and affinity of enzymes respectively. The metabolic index (dehydrogenase activity/organic carbon (OC)) was found to be correlated with Vmax of dehydrogenase (r = 0.953; p

Monty, Kujur; Amiya, Kumar Patel.

2014-03-01

288

Retention based bio accessibility of carotenoids in green leafy vegetables: effect of different Indian culinary practices  

Directory of Open Access Journals (Sweden)

Full Text Available Back ground: Green Leafy Vegetables (GLV is pigment-rich and nutritionally relevant functional food sources with unique phytochemical constituents that include carotenoids which are precursors for vitamin A and protect cells from oxidation and cellular damage. Cooking processes and other factors such as temperature, light and alteration in moisture content generally promote either isomerization (trans to cis form or oxidative degradation of carotenoids to epoxides. Rationale: Studies pertaining to the effect of cooking methods on dietary carotenoids bio accessibility and their retention percent are scarce, particularly in an Indian Diasporas. Objective: Present study was to determine the carotenoids retention based bio accessibility in GLV such as amaranth (Amaranthus gangeticus, spinach (Spinacia oleracea and curry leaves (Murraya koenigii, when subjected to domestic cooking methods of microwave cooking, sautéing, pressure cooking, steaming and deep frying in oil, for a time duration of 8 and 12 minutes, either with lid closed or open. Method: The retention based bio accessibility of carotenoids were quantified by rapid separation liquid chromatography (RSLC using RP-C-18 column (150mm×4.6µ with 70% acetonitrile, 20% dichlomethane and 10% methanol for 20 minutes at flow rate of 0.5 ml/min. Results: The maximum retention based bio accessibility of total carotenoids and ?-carotene were observed with micro wave cooking, steaming and sautéing methods. (Spinach: 57.88% and 55.92%, Amaranth: 56.15% and 57.49%, Curry leaves: 50.55% and 52.66% respectively. Conclusion: The reduction in the contents of carotenes in GLVs in correlation to various cooking methods are discussed which would be valuable for food researchers, nutritionists as well as health practitioners and dietitians, in developing and promoting nutritionally balanced diets and minimize vitamin A deficiency in Indian context.

Sreeenivasa J Rao

2014-12-01

289

THE EFFECT OF STORAGE TIME IN DIFFERENT TEMPERATURE ON NATIVE CHICKEN EGG HAUGH UNIT AND YOLK INDEX  

OpenAIRE

Three hundred sixty native chicken eggs was test on the effect of storage time in different temperature on haugh unit and yolk index. The aim of this research is to get the effect of storage time in different temperatures : 300 – 32oC (RH 54%), 280 – 290 C (RH 58%) and 150 – 180 C (RH 80%); on native chicken eggs haugh unit and yolk index. This experiment used Completely Randomized Design (CRD) on three different temperatures (30-320C, 28-290C and 15­180C) and each treatment was repeat...

Lengkey, Hendronoto Arnoldus W.; Tuti Widjastuti; Sjafril Darana

2012-01-01

290

The hydrological responses of different land cover types in a re-vegetation catchment area of the Loess Plateau, China  

Directory of Open Access Journals (Sweden)

Full Text Available The impact of re-vegetation on soil moisture dynamics was investigated by comparing five land cover types. Soil moisture and temperature variations under grass (Andropogon, subshrub (Artemisia scoparia, shrub (Spiraea pubescens, tree (Robinia pseudoacacia, and crop (Zea mays vegetation were monitored in an experiment performed during the growing season of 2011. There were more than 10 soil moisture pulses during the period of data collection, and the surface soil moisture of all of the land cover types showed an increasing trend. Corn cover was associated with consistently higher soil moisture readings than the other surfaces. Grass and subshrubs showed an intermediate moisture level, with that of grass being slightly higher than that of subshrub most of the time. Shrubs and trees were characterized by lower soil moisture readings, with the shrub levels consistently being slightly higher than those of the trees. With the exception of the corn land cover type, the average soil temperature showed the same regime as the average moisture content, but exhibiting a downward trend throughout the observation period. Three typical decreasing periods were chosen to compare the differences in water losses. In periods of both relatively lower and higher water soil moisture contents, subshrubs lost the largest amount of water. The daily water loss associated with corn was most variable. The tree and shrub sites presented an intermediate level, with that of tree being slightly higher compared to shrub; the daily water loss trends of these two land cover types were similar and were more stable than those of the other types. The amount of water loss related to the grass land cover type is determined by the initial moisture content. Soil under subshrubs acquired and retained soil moisture resources more efficiently than the other cover types, representing an adaptive vegetation type in this area.

S. Wang

2012-05-01

291

The hydrological responses of different land cover types in a re-vegetation catchment area of the Loess Plateau, China  

Science.gov (United States)

The impact of re-vegetation on soil moisture dynamics was investigated by comparing five land cover types. Soil moisture and temperature variations under grass (Andropogon), subshrub (Artemisia scoparia), shrub (Spiraea pubescens), tree (Robinia pseudoacacia), and crop (Zea mays) vegetation were monitored in an experiment performed during the growing season of 2011. There were more than 10 soil moisture pulses during the period of data collection, and the surface soil moisture of all of the land cover types showed an increasing trend. Corn cover was associated with consistently higher soil moisture readings than the other surfaces. Grass and subshrubs showed an intermediate moisture level, with that of grass being slightly higher than that of subshrub most of the time. Shrubs and trees were characterized by lower soil moisture readings, with the shrub levels consistently being slightly higher than those of the trees. With the exception of the corn land cover type, the average soil temperature showed the same regime as the average moisture content, but exhibiting a downward trend throughout the observation period. Three typical decreasing periods were chosen to compare the differences in water losses. In periods of both relatively lower and higher water soil moisture contents, subshrubs lost the largest amount of water. The daily water loss associated with corn was most variable. The tree and shrub sites presented an intermediate level, with that of tree being slightly higher compared to shrub; the daily water loss trends of these two land cover types were similar and were more stable than those of the other types. The amount of water loss related to the grass land cover type is determined by the initial moisture content. Soil under subshrubs acquired and retained soil moisture resources more efficiently than the other cover types, representing an adaptive vegetation type in this area.

Wang, S.; Fu, B. J.; Gao, G. Y.; Zhou, J.

2012-05-01

292

Association of Intrarenal Resistive Index with Different Stages of Diabetic Nephropathy  

Directory of Open Access Journals (Sweden)

Full Text Available Background/Objective: Intrarenal resistive index"n(RI is used commonly for evaluation and prediction"nof renal diseases, but its use is little explored in the"nprediction of diabetic nephropathy (DN. We used"nDoppler analysis to determine whether intrarenal RI"nis related to different stages of diabetic nephropathy."nPatients and Methods: Fifty-seven diabetic patients"nin three equal groups of different stages of DN (stage"n1,2,3 and 19 nondiabetics as the control group were"nincluded. RI of interlobar arteries was determined"nusing Siemens G50 in three poles of each kidney and"nthe mean of them was assumed as intrarenal RI for"neach case."nResults: The mean of intrarenal RI was 63.1±5.6 in"nthe control group, 59.8±2.2 in DN stage 1, 61.4±5.8 in"nDN stage 2 and 82.4±11.1 in DN stage 3. There is no"nsignificant difference in RI between the control, DN"nstage 1 and DN stage 2 groups (P value>0.05. There"nis only significant increase in RI in DN stage 3 (P"nvalue <0.001. Using R.O.C curve cut off point of 0.71"nfor RI with the sensivity of 84.2% and specificity of"n94.7% can be used for prediction of end stage diabetic"nnephropathy."nConclusion: According to this study, intrarenal RI"nis not useful for prediction of early stages of diabetic"nnephropathy.

Maryam Moradi

2011-05-01

293

Promoting fruit and vegetable consumption in different lifestyle groups: recommendations for program development based on behavioral research and consumer media data.  

Science.gov (United States)

Fruit and vegetable consumption affects the etiology of cardiovascular disease as well as many different types of cancers. Still, Americans' consumption of fruit and vegetables is low. This article builds on initial research that assessed the validity of using a consumer-based psychographic audience segmentation in tandem with the theory of planned behavior to explain differences among individuals' consumption of fruit and vegetables. In this article, we integrate the findings from our initial analyses with media and purchase data from each audience segment. We then propose distinct, tailored program suggestions for reinventing social marketing programs focused on increasing fruit and vegetable consumption in each segment. Finally, we discuss the implications of utilizing a consumer-based psychographic audience segmentation versus a more traditional readiness-to-change social marketing segmentation. Differences between these two segmentation strategies, such as the ability to access media usage and purchase data, are highlighted and discussed. PMID:18935880

Della, Lindsay J; DeJoy, David M; Lance, Charles E

2008-01-01

294

Large Differences in Terrestrial Vegetation Production Derived from Satellite-Based Light Use Efficiency Models  

OpenAIRE

Terrestrial gross primary production (GPP) is the largest global CO2 flux and determines other ecosystem carbon cycle variables. Light use efficiency (LUE) models may have the most potential to adequately address the spatial and temporal dynamics of GPP, but recent studies have shown large model differences in GPP simulations. In this study, we investigated the GPP differences in the spatial and temporal patterns derived from seven widely used LUE models at the global scale. The result shows ...

Wenwen Cai; Wenping Yuan; Shunlin Liang; Shuguang Liu; Wenjie Dong; Yang Chen; Dan Liu; Haicheng Zhang

2014-01-01

295

Physical Explanation on Designing Three Axes as Different Resolution Indexes from GRACE Satellite-Borne Accelerometer  

International Nuclear Information System (INIS)

The GRACE Earth's gravitational field complete up to degree and order 120 is recovered based on the same and different three-axis resolution indexes from satellite-borne accelerometer using the improved energy conservation principle. The results show that designing XA1(2) as low-sensitivity axis (3 × 10?9m/s2) of accelerometer and designing YA1(2) and ZA1(2) as high-sensitivity axes (3 × 10?10 m/s2) are reasonable. The physical reason why the resolution of XA1(2) is one order of magnitude lower than YA1(2) and ZA1(2) is that non-conservative forces acting on GRACE satellites are mainly decomposed into YA1(2) and ZA1(2) in the orbital plane. Since XA1(2) is not orthogonal accurately to orbital plane during the development of accelerometer, the measurement of XA1(2) can not be thrown off entirely, but be reduced properly

296

Effects of different dietary cation-anion balance and cellulase on blood biochemical indexes in sheep  

International Nuclear Information System (INIS)

Five sheep with average live weight of 38 kg were selected and fitted with permanent ruminal fistulae for the study of the influence of DCAB and cellulase on blood biochemical indexes in sheep. With the design of 5 x 5 Latin square, the goats were undergone four groups of treatments. As sheep in control group were only fed with basic feed, other treatments were fed with basic feed and additives. Those additives were: treatment 1 with cellulase (0.2% of dietary), treatment 2 with DCAB1 (20 mEq/100g DM), treatment 3 with cellulase (0.2% of dietary) and DCAB1 (20 mEq/100g DM) and treatment 4 with cellulase (0.2% of dietary) and DCAB2 (40 mEq/100 g DM). The results show that different DCAB and cellulase had no apparent influence on the concentrations of T3 and T4 (P>0.05), but they had significant influence on the concentration of insulin (P0.05). The study indicated that addition of 0.2% cellulase to dietary while adjusting DCAB to 0.2-40 mEq/100 g DM respectively did not destroy tissues and organs of sheep. (authors)

297

Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability  

DEFF Research Database (Denmark)

The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25–200°C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO2), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos? values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos? values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability.

Ashokkumar, Saranya; Adler-Nissen, Jens

2012-01-01

298

Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability  

Science.gov (United States)

The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25-200 °C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO2), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos ? values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos ? values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability.

Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

2012-12-01

299

Animal and vegetal pole cells of early Xenopus embryos respond differently to maternal dorsal determinants: implications for the patterning of the organiser  

International Nuclear Information System (INIS)

The maternal dorsal determinants required for the specification of the dorsal territories of Xenopus early gastrulae are located at the vegetal pole of unfertilised eggs and are moved towards the prospective dorsal region of the fertilised egg during cortical rotation. While the molecular identity of the determinants is unknown, there are dorsal factors in the vegetal cortical cytoplasm (VCC). Here, we show that the VCC factors, when injected into animal cells activate the zygotic genes Siamois and Xnr3, suggesting that they act along the Wnt/?-catenin pathways. In addition, Siamois and Xnr3 are activated and at the vegetal pole of UV-irradiated embryos, indicating that these two genes are targets of the VCC factors in all embyronic cells. However, the consequences of their activation in cells that occupy different positions along the animal-vegetal axis differ. Dorsal vegetal cells of normal embryos or VCC-treated injected animal cells are able to dorsalise ventral mesoderm in conjugate experiments but UV-treated vegetal caps do not have this property. We propose that the regionalisation of the organiser during gastrulation proceeds from the differential interpretation along the animal-vegetal axis of the activation of the VCC/?-catenin/Siamois pathway. (author)

300

Mercury methylation in sediments of a Brazilian mangrove under different vegetation covers and salinities.  

Science.gov (United States)

The presence and formation of methylmercury (MMHg), a highly toxic form of Hg, in mangrove ecosystems is poorly studied. Therefore the aim of this study was to evaluate mercury methylation potentials in sediment, litter and root samples (Avicennia shaueriana and Spartina alterniflora) from different regions of a mangrove ecosystem, as well as the influence of salinity on methylation. Sediment was sampled under different depths and in mangrove regions with different plant covers and salinities. All samples were incubated with (203)Hg and MM(203)Hg was extracted and measured by liquid scintillation. MMHg was formed in all samples and sites tested including plant roots and litter. Higher Hg methylation was found in the superficial fraction of sediments (0.47-7.82%). Infralittoral sandy sediment had low MMHg formation (0.44-1.61%). Sediment under Rhizophora mangle had lower MMHg formation (0.018-2.23%) than under A. shaueriana (0.2-4.63%) and Laguncularia racemosa (0.08-7.82). MMHg formation in sediment tended to increase with salinity but the differences were not significant. Therefore, MMHg formation occurs in different sites of mangrove ecosystems and may be an important threat that requires further study. PMID:25732633

de Oliveira, Diana Ciannella Martins; Correia, Raquel Rose Silva; Marinho, Claudio Cardoso; Guimarães, Jean Remy Davée

2015-05-01

301

Advanced Spaceborne Thermal Emission and Reflection Radometer (ASTER) Enhanced Vegetation Index (EVI) Products from Global Earth Observation (GEO) Grid: An Assessment Using Moderate Resolution Imaging Spectroradiometer (MODIS) for Synergistic Applications  

OpenAIRE

We assessed the compatibility of three Advanced Spaceborne Thermal Emission and Reflection Radometer (ASTER) based Enhanced Vegetation Index (EVI) products generated in the GEO Grid system to Moderate Resolution Imaging Spectroradiometer (MODIS) EVI. The three products were two forms of the two-band EVI with ASTER red and NIR bands but without a blue band and the original, three-band EVI computed with ASTER red and NIR, and MODIS blue reflectances. Our assessment results showed good compatibi...

Satoshi Tsuchida; Tomoaki Miura; Hirokazu Yamamoto

2012-01-01

302

Bone strength index in adolescent girls: does physical activity make a difference?  

OpenAIRE

Background: Bone strength index (BSI) combines bone mineral and bone biomechanical properties to measure resistance to bending. This index may have greater clinical significance than the more often described markers of bone mineral content (BMC), areal density, or geometry alone and, in turn, may show a stronger relation to fracture risk. The BSI is the product of volumetric cortical bone mineral density (BMD) and cross sectional moment of inertia within a region of interest. Calculations com...

Greene, D.; Naughton, G.; Briody, J.; Kemp, A.; Woodhead, H.; Corrigan, L.; Karlsson, M.

2005-01-01

303

Estimates of leaf area index from spectral reflectance of wheat under different cultural practices and solar angle  

Science.gov (United States)

The influence of management practices and solar illumination angle on the leaf area index (LAI) was estimated from measurements of wheat canopy reflectance evaluated by two methods, a regression formula and an indirect technique. The date of planting and the time of irrigation in relation to the stage of plant growth were found to have significant effects on the development of leaves in spring wheat. A reduction in soil moisture adversely affected both the duration and magnitude of the maximum LAI for late planting dates. In general, water stress during vegetative stages resulted in a reduction in maximum LAI, while water stress during the reproductive period shortened the duration of green LAI in spring wheat. Canopy geometry and solar angle also affected the spectral properties of the canopies, and hence the estimated LAI. Increase in solar zenith angles resulted in a general increase in estimated LAI obtained from both methods.

Asrar, G.; Kanemasu, E. T.; Yoshida, M.

1985-01-01

304

Lactic acid fermentation in vegetable juices supplemented with different content of brewer’s yeast autolysate  

OpenAIRE

The work is concerned with the conditions for lactic acid fermentation in a mixture of beetroot (Beta vulgaris L) juice and carrot (Daucus carota L) juice and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748.Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using the higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 ...

Rakin Marica B.; Baras Josip K.; Vukašinovi? Maja S.

2005-01-01

305

Chemistry of soil solutions under different kinds of vegetation in the vicinity of a thermal power station  

Energy Technology Data Exchange (ETDEWEB)

The paper discusses the influence of atmospheric deposition on the chemical characteristics of soil solutions in a small catchment area in NW Spain. The soils, were sampled from seven sites supporting different forms of vegetation (deciduous and pine forest and heath). Soil solutions were extracted, by the column displacement method, from soil samples collected monthly from March 1992 until November 1993. The most common ions in all horizons were Cl{sup -} and Na{sup +} due to marine influence. In the surface horizons (0-10 cm), relatively high concentrations of SO{sub 4}{sup 2-} (150-380 {mu}mol) and Zn (similar to 2 {mu} mol) were obtained, with good correlation between the two ions. These results, along with the prevalence of inorganic forms of Al(50-90% of total Al), were related to the effects of acidic deposition in the catchment area.

Fernandez Sanjurjo, M.J.; Alvarez, E.; Vega, V.F.; Garcia Rodeja, E. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola

1998-12-01

306

Evaluation of the Uptake and Accumulation of Metals by Some Commonly Irrigated Vegetables in Soils Treated with Different Concentrations of these Metals  

OpenAIRE

The uptake of some trace elements namely, chromium, nickel, cadmium and lead by some vegetables commonly irrigated were studied under glasshouse conditions. Experiments were conducted in plastic pots using some selected vegetables, lettuce (Lactuca sativa), okra (Abelmoschus esculentus) and pepper (Capsicum annum) grown on sandy loam soils treated with different concentrations of these metals. The treatments investigated include zero application (control), 10, 50 and 100 ?g dm-3 metal...

Haliru, M.; Ajibola, V. O.; Agbaji, E. B.

2009-01-01

307

STRUCTURE AND COMPOSITION OF THE REGENERATION STRATUM AND ASSOCIATED VEGETATION OF DIFFERENT SUCCESSION STAGES IN EAST OF PARANÁ STATE  

Directory of Open Access Journals (Sweden)

Full Text Available In recent decades, the human activities caused the overall decline in biodiversity and, to understand the impacts on plant communities, it is necessary to analyze the regenerative potential of the forest. Studies on the floristic composition and the structure of the guild of seedlings in different succession stages and historical conditions can describe the patterns of species replacement and help understand the forest dynamics. Thus, the objective of this study was to compare floristic and structural layer of the regeneration and associated vegetation in two succession stages of two areas with different historical uses located in the city of Campina Grande do Sul, in Paraná state. Seedlings were collected in two fragments of the secondary forest at the initial and at the intermediate stages, with historical use of clear and selective cuts, respectively. One-hundred and six plots of 0,16 m² were delimited and all individual plants with up to 10 - 50 cm high were collected, identified, quantified and divided into two groups: seedlings of tree species and species associated for the phytosociological analysis. The species were also classified according to their habits, dispersion mode and succession stages and the floristic similarity between areas was established by Sorensen’s, Bray & Curtis’ and Morisita-Horn’s indices. The analysis suggests a possible influence of historical use and the successional stages of regeneration and the associated vegetation. The analysis of similarity indicates a gradient of regeneration, in which the intermediate stage of the clear cut area is similar to the early stage of the selective cutting area.

Marco Antonio Gomes Souto

2011-09-01

308

Fractional vegetation cover estimation from Proba/CHRIS data: Methods, analysis of angular effects and application to the land surface emissivity retrieval  

OpenAIRE

In this paper, two different methods for fractional vegetation cover (FVC) retrieval from CHRIS (Compact High Resolution Imaging Spectrometer) data based on vegetation indices have been analyzed. The first method uses NDVI (Normalized Difference Vegetation Index) values, as suggested, among others, by Carlson and Ripley (1997) and Gutman and Ignatov (1998), and the second method uses VARI (Variable Atmospherically Resistant Index) values as suggested by Gitelson et al. (2002). In addition, a ...

Jime?nez-mun?oz, Jc; Sobrino, Ja; Guanter, L.; Moreno, J.; Plaza, A.; Matfaez, P.

2005-01-01

309

Attraction of Sphenophorus levis Vaurie adults (Coleoptera: Curculionidae) to vegetal tissues at different conservation levels  

International Nuclear Information System (INIS)

The occurrence of the sugarcane weevil Sphenophorus levis Vaurie is important in sugarcane in some regions in Brazil. Damage is caused by the larvae as they bore into the nodes and can reach 30 ton/ha/year. Many control alternatives have been attempted, but none were satisfactory, except for the use of toxic baits. Therefore, it is necessary to optimize their efficiency or to propose new techniques. The objective of the current study was to evaluate the attractiveness of adults of S. levis to sugarcane nodes and pineapple peelings in an 'Y' tube olfactometer. The sugarcane internodes were treated with 10% molasses, and tested after different periods of fermentation (24, 48 e 72h), at different times of the day (diurnal and nocturnal) and with both sexes. These tests were carried out in order to correlate the response of S. levis to ethyl acetate and ethanol release as a result of the fermentation process. The release of both compounds was monitored by gas chromatography-mass spectrometry (GC-MS). Our data indicated that sugarcane internodes mixed with 10% molasses fermented for 24h and 48h were the most attractive to S. levis (up to 90%). Pineapple peelings attracted 62.5% of the tested insects. The olfactory response was higher during the day, and no differences were found between the sexes. The production of ethanol in all plant substrates was higher than ethyl acetate, but we could not establish a clear correlation with the insect response to baits. (author) insect response to baits. (author)

310

Vegetative development of orchid hybrid in different substratesDesenvolvimento vegetativo de híbrido de orquídea em diferentes substratos  

Directory of Open Access Journals (Sweden)

Full Text Available For commercial production of orchids, it is essential to use a good substrate, and the selection of this material is very important to evaluate aspects of the economic, physical, chemical, biological, and ecological points of view. The aim of this study was to evaluate the development of clones of BLC Nan Chang Silk ‘Olimpic Torch’ on different substrates. The substrates were: T1: tree fern fiber “xaxim” (control, T2: coconut fiber, T3: composted pine bark, T4: plant coal, T5: composted pine bark + coconut fiber (1:1 v/v T6: coconut fiber + plant coal (1:1 v/v, T7: plant coal + composted pine bark (1:1 v/v, T8: plant coal + composted pine bark + coconut fiber ( 1:1:1 v/v/v. The seedlings were grown in pots of polypropylene, kept in a nursery with 80% of brightness. We evaluated 24 months after the start of the experiment: number of pseudobulbs, the lenght of pseudobulbs, height of the plant area, height of the aerial part / lenght of the pseudobulbs and pH and electrical conductivity of the substrate. Based on the parameters of vegetative development it was concluded that all the evaluated substrates can be efficiently used for the cultivation of BLC Nan Chang Silk ‘Olimpic Torch’. A produção de orquídeas é uma atividade em crescente expansão nos mercados nacional e internacional, tornando-se evidente a necessidade de informações que permitam a otimização do seu cultivo. Para a produção comercial de orquídeas, é imprescindível a utilização de um substrato que permita maior crescimento das mudas e, na seleção deste material, é muito importante avaliar aspectos do ponto de vista econômico, físico, químico, biológico e ecológico. O objetivo deste trabalho foi avaliar o desenvolvimento de clones de BLC Nan Chang Silk ‘Olimpic Torch’, obtida do cruzamento entre BLC. Bryce Canyon x BLC. Pamela Hetherington, em diferentes substratos. Os substratos avaliados foram: T1: fibra de xaxim (controle; T2: fibra de coco; T3: casca de pinus compostado; T4: carvão vegetal; T5: casca de pinus compostado + fibra de coco (1:1 v/v; T6: fibra de coco + carvão vegetal (1:1 v/v; T7: carvão vegetal + casca de pinus compostado (1:1 v/v; T8: carvão vegetal + casca de pinus compostado + fibra de coco (1:1:1 v/v/v. As mudas foram cultivadas em vasos de polipropileno, permanecendo em viveiro com 80% de luminosidade. Os parâmetros avaliados 24 meses após o início do experimento foram: número de pseudobulbos, diâmetro médios dos pseudobulbos, altura da parte área da planta, relação altura da parte aérea /comprimento dos pseudobulbos e o pH e a condutividade elétrica dos substratos. Com base nos parâmetros de desenvolvimento vegetativos concluiu-se que todos os substratos avaliados podem ser utilizados eficientemente para o cultivo de BLC Nan Chang Silk ‘Olimpic Torch’.

Alessandro Garrett Dronk

2012-12-01

311

Lactic acid fermentation in vegetable juices supplemented with different content of brewer’s yeast autolysate  

Directory of Open Access Journals (Sweden)

Full Text Available The work is concerned with the conditions for lactic acid fermentation in a mixture of beetroot (Beta vulgaris L juice and carrot (Daucus carota L juice and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748.Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using the higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 has shown better growth and lactic acid production than L. acidophilus NCDO 1748.

Rakin Marica B.

2005-01-01

312

Vegetation against dune mobility  

CERN Document Server

Vegetation is the most common and most reliable stabilizer of loose soil or sand. This ancient technique is for the first time cast into a set of equations of motion describing the competition between aeolian sand transport and vegetation growth. Our set of equations is then applied to study quantitatively the transition between barchans and parabolic dunes driven by the dimensionless fixation index $\\theta$ which is the ratio between dune characteristic erosion rate and vegetation growth velocity. We find a fixation index $\\theta_c$ below which the dunes are stabilized characterized by scaling laws.

Duran, O; Duran, Orencio; Herrmann, Hans J.

2006-01-01

313

Glycaemic index of different coconut (Cocos nucifera)-flour products in normal and diabetic subjects.  

Science.gov (United States)

The glycaemic index (GI) of commonly consumed bakery products supplemented with increasing levels of coconut (Cocos nucifera) flour was determined in ten normal and ten diabetic subjects. Using a randomized crossover design, the control and test foods were fed in random order on separate occasions after an overnight fast. Blood samples were collected through finger prick before and after feeding and were analysed for glucose levels using a clinical chemistry analyser. The significantly low-GI (cake (GI 51.8 (sem 3.3)), with 200-250 g coconut flour/kg (Pflour/kg had GI ranging from 61.3 to 71.4. Among the test foods, pan de sal (GI 87.2 (sem 5.5)) and multigrain loaf (GI 85.2 (sem 6.8)) gave significantly higher GI with 50 and 100 g coconut flour/kg respectively (Pflour/kg respectively gave a GI ranging from 62.7 to 71.6 and did not differ significantly from the test foods with 150 g coconut flour/kg (Pflour. In conclusion, the GI of coconut flour-supplemented foods decreased with increasing levels of coconut flour and this may be due to its high dietary fibre content. The results of the present study may form a scientific basis for the development of coconut flour as a functional food. However, the fat content of coconut flour-supplemented food should always be considered to optimize the functionality of coconut fibre in the proper control and management of diabetes mellitus. PMID:13129460

Trinidad, Trinidad P; Valdez, Divinagracia H; Loyola, Anacleta S; Mallillin, Aida C; Askali, Faridah C; Castillo, Joan C; Masa, Dina B

2003-09-01

314

Effects of different vegetation on temperature in an urban building environment. Micro-scale numerical experiments  

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional micro-scale model is used to study the effects of various greenery on temperature in a built-up environment. Green design elements like roofs and facades, lawns in courtyards and single trees are studied individually as well as in various combinations. Measures for comparison are temperatures at 2 m height and mean temperatures for the urban atmosphere up to the building height. Different types of greenery can reduce local temperatures up to 15 K during specific daytime hours. However, this extraordinary effect is restricted to a short time and especially to the direct surroundings, while an impact over larger distances is small. Roof and facade greenery have hardly any influence on temperature at the 2 m level but reduce daytime heating of the urban atmosphere to a minor degree, while the relevance of trees is more or less limited to the shadow effect. A significant decrease in urban temperatures can be achieved only with a large number of very different individual green elements. The largest effect on the urban atmosphere was simulated for a change in albedo resulting in a temperature decrease of some degrees around noon. (orig.)

Gross, Guenter [Hannover Univ. (Germany). Inst. fuer Meteorologie und Klimatologie

2012-08-15

315

The Regularities of Mutagenic Action of gamma-Radiation on Vegetative Bacillus subtilis Cells with Different Repair Genotype  

CERN Document Server

The regularities of induction of his^-\\to his^+ mutations in vegetative Bacillus subtilis cells with different repair capacity after gamma-irradiation have been studied. The wild type cells, polA1, recE4, recA, recP, add5, recH were used in experiments. It was shown that radiation-induced mutagenesis is determined by a repair genotype of cells. The blocking of different reparation genes is reflected on mutagenesis ratio by the various ways. A frequency of induction mutations in polA strain is higher than in wild type cells and it is characterized by the linearly-quadratic dose curve. The different rec^- strains that belong to various epistatic groups reveal an unequal mutation induction. The add5 and recP strains are characterized by the high-level induction mutations in contrast with the wild type cells. The mutagenesis in recE and recH strains, on the contrary, sharply reduces. The different influence of rec genes inhering to various epistatic groups on mutagenesis in Bacillus subtilis cells probably reflec...

Boreyko, A V; Krasavin, E A

2000-01-01

316

Temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover  

Science.gov (United States)

Acidification of forest soils is a natural degradation process which can be significantly enhanced by anthropogenic activities. Inputs of basic cations (BC - Ca, Mg and K) via precipitation, litter and soil organic matter decomposition and also via inter-soil weathering may partially mitigate the consequences of this degradation process. The aim of this study is to assess the temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover. The Jizera Mountains region (Czech Republic, northern Bohemia) was chosen as a representative soil mountainous ecosystem strongly affected by acidification. Soil and precipitation samples were collected at monthly basis from April till October/ November during the years 2009-2011. Study spots were delimited under two contrasting vegetation covers - beech and spruce monoculture. Prevailing soil types were classified as Alumic Cambisols under beech and Entic Podzols under spruce stands (according to FAO classification). Soil samples were collected from surface fermentation (F) and humified (H) organic horizons and subsurface B horizons (cambic or spodic). The collected soil samples were analyzed immediately under laboratory condition in a "fresh" state. Unsieved fresh samples were extracted by deionised water. The content of main elements (Ca, Mg, K, Al and Fe) was determined by ICP-OES. The content of major anions (SO42-, NO3-, Cl- and F-) was determined by ion-exchange chromatography (IC). Content of major anions and main elements were determined in the precipitation samples (throughfall, stemflow and bulk) as well. Besides computing the basic statistical parameters (mean, median, variance, maximum, minimum, etc.) we also employed other statistical methods such as T-test and ANOVA to assess the differences between beech and spruce vegetation spots. To carry out the temporal variability in the data we used the time series analysis and short-term forecasting by Holt-Winters exponential smoothing and ARIMA models. Our results clearly exhibit differences in the horizontal and spatial distribution of BC. The influences of the study spot, i.e. the influence of stand factors e.g. vegetation covers on BC distribution are well pronounced. The highest amounts of aqueous extractable BC were identified in the F and H organic horizons. The contents of Ca and Mg were significantly higher under beech cover than under spruce cover. The influence of seasonality on BC content and distribution was the strongest in the upper organic horizons. The annual changes are less pronounced in inner mineral B horizons. We have observed a significant influence of the snow melting period - after this event the content of BC was the lowest. In contrast, the BC content rises during the summer period - the time of high biological activity and accelerated organic matter decomposition. This period is again followed by a BC content decrease during the fall period - the time of gradually decreasing biological activity and high precipitation. Generally, we can conclude that the seasonal variations are higher than annual and spatial for both sites.

Tejnecky, V.; Bradová, M.; Boruvka, L.; Vasat, R.; Nemecek, K.; Ash, C.; Sebek, O.; Rejzek, J.; Drabek, O.

2012-12-01

317

Mapping agroecological zones and time lag in vegetation growth by means of Fourier analysis of time series of NDVI images  

Science.gov (United States)

Examples are presented of applications of a fast Fourier transform algorithm to analyze time series of images of Normalized Difference Vegetation Index values. The results obtained for a case study on Zambia indicated that differences in vegetation development among map units of an existing agroclimatic map were not significant, while reliable differences were observed among the map units obtained using the Fourier analysis.

Menenti, M.; Azzali, S.; Verhoef, W.; Van Swol, R.

1993-01-01

318

Coverage mobilization by different no-tillage in-line handling mechanisms / Mobilização da cobertura vegetal por diferentes mecanismos em semeadura direta  

Scientific Electronic Library Online (English)

Full Text Available A cobertura vegetal sobre o solo age positivamente na manutenção da temperatura e da umidade do solo; contudo, vem impondo condições operacionais específicas às semeadoras. O objetivo do trabalho foi avaliar o desempenho de diferentes mecanismos quanto à mobilização da palha, empregados em uma semea [...] dora direta. A área experimental foi conduzida em solo argiloso, em semeadura direta com alto volume de palha de sorgo. O experimento foi implantado no delineamento de blocos casualizados, sendo que os tratamentos consistiram na combinação de dois mecanismos à frente da haste sulcadora, compostos pelo disco de corte e rodas de varredura, e três mecanismos atrás do sulcador da semente, discos cobridores modelos protótipo M1, modelo comercial e Spider, sendo que a combinação disco de corte e modelo Spider não foi avaliada. Foram avaliados o índice de permanência da cobertura e a massa da cobertura vegetal na superfície e no interior da linha. O tratamento que continha o mecanismo rodas de varredura removeu eficientemente a palha da superfície da linha de semeadura bem como os de retorno atuaram na reposição da palha. Constatou-se que o uso do disco de corte à frente da semeadora contribuiu para o aumento da introdução da palha no interior da linha, três vezes mais em relação ao sistema rodas de varredura, quando eles operam isoladamente. A utilização dos mecanismos cobridores adicionados às rodas de varredura reduziu a introdução de palha no interior da linha e manteve a cobertura sobre a linha, similar ao tratamento disco de corte operando isoladamente. Abstract in english Vegetation cover on soil acts positively in maintaining temperature and soil moisture, yet, it has been imposing specific operational conditions on seeders. The objective of this study was to evaluate performance of different mechanisms regarding straw mobilization, employed in a no-till seeder. The [...] experimental area was conducted on clayey soil under no-tillage with a large quantity of sorghum residue. The experiment was established in a randomized block design, as the treatments consisted of a combination of two mechanisms at front of the furrow opener composed of cutting disc and row cleaners, and three mechanisms behind the seed furrower, covering discs prototype model M1, Spider and commercial model, with the combination of cutting disc and Spider model not being evaluated. We assessed the coverage permanence on soil index, vegetation mass on surface and inside the line. The treatment containing the row cleaner mechanism efficiently removed straw from the surface of sowing line as well as the return one acted on straw replacement. It was identified that use of the cutting disc at the front of seeder contributed to the increase of straw installation inside the line, three times more than in the row cleaner system when operating individually. Covering mechanism with row cleaners reduced straw inside the line and kept line covering similar to treatment of cutting disc operating alone.

EVANDRO M., BRANDELERO; AUGUSTO G. DE, ARAÚJO; RICARDO, RALISCH.

2015-02-01

319

Trends in the surface vegetation dynamics of the national parks of Spain as observed by satellite sensors  

OpenAIRE

Questions: What are the current dynamics, as observed by synoptic sensors, of surface vegetation in Spanish protected areas? Are these areas and their vegetation types uniformly affected by the increase in vegetation greenness detected throughout Europe? Location: Iberian National Parks of Spain. Methods: We used the normalized difference vegetation index (NDVI) from global inventory modeling and mapping studies (GIMMS) advanced very high resolution radiometer (AVHRR) dataset to monitor...

Alcaraz-segura, Domingo; Cabello, Javier; Paruelo, Jose? M.; Delibes, M.

2008-01-01

320

Assessment of soil biological quality index (QBS-ar) in different crop rotation systems in paddy soils  

Science.gov (United States)

New methods, based on soil microarthropods for soil quality evaluation have been proposed by some Authors. Soil microarthropods demonstrated to respond sensitively to land management practices and to be correlated with beneficial soil functions. QBS Index (QBS-ar) is calculated on the basis of microarthropod groups present in a soil sample. Each biological form found in the sample receives a score from 1 to 20 (eco-morphological index, EMI), according to its adaptation to soil environment. The objective of this study was to evaluate the effect of various rotation systems and sampling periods on soil biological quality index, in paddy soils. For the purpose of this study surface soil samples (0-15 cm depth) were collected from different rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) with three replications, and four sampling times in April (after field preparation), June (after seedling), August (after tillering stage) and October (after rice harvesting). The study area is located in paddy soils of Verona area, Northern Italy. Soil microarthropods from a total of 48 samples were extracted and classified according to the Biological Quality of Soil Index (QBS-ar) method. In addition soil moisture, Cumulative Soil Respiration and pH were measured in each site. More diversity of microarthropod groups was found in June and August sampling times. T-test results between different rotations did not show significant differences while the mean difference between rotation and different sampling times is statistically different. The highest QBS-ar value was found in the fallow-rice rotation in the forth soil sampling time. Similar value was found in soya-rice-rice rotation. Result of linear regression analysis indicated that there is significant correlation between QBS-ar values and Cumulative Soil Respiration. Keywords: soil biological quality index (QBS-ar), Crop Rotation System, paddy soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; haefele, Stephan

2013-04-01

321

Sensitivity of fire weather index to different reanalysis products in the Iberian Peninsula  

Directory of Open Access Journals (Sweden)

Full Text Available Wildfires are a major concern on the Iberian Peninsula, and the establishment of effective prevention and early warning systems are crucial to reduce impacts and losses. Fire weather indices are daily indicators of fire danger based upon meteorological information. However, their application in many studies is conditioned to the availability of sufficiently large climatological time series over extensive geographical areas and of sufficient quality. Furthermore, wind and relative humidity, important for the calculation of fire spread and fuel flammability parameters, are relatively scarce data. For these reasons, different reanalysis products are often used for the calculation of surrogate fire danger indices, although the agreement with those derived from observations remains as an open question to be addressed.

In this study, we analyze this problem focusing on the Canadian Fire Weather Index (FWI – and the associated Seasonal Severity Rating (SSR – and considering three different reanalysis products of varying resolutions on the Iberian Peninsula: NCEP, ERA-40 and ERA-Interim. Besides the inter-comparison of the resulting FWI/SSR values, we also study their correspondence with observational data from 7 weather stations in Spain and their sensitivity to the input parameters (precipitation, temperature, relative humidity and wind velocity.

As a general result, ERA-Interim reproduces the observed FWI magnitudes with better accuracy than NCEP, with lower/higher correlations in the coast/inland locations. For instance, ERA-Interim summer correlations are above 0.5 in inland locations – where higher FWI magnitudes are attained – whereas the corresponding values for NCEP are below this threshold. Nevertheless, departures from the observed distributions are generally found in all reanalysis, with a general tendency to underestimation, more pronounced in the case of NCEP. In spite of these limitations, ERA-Interim may still be useful for the identification of extreme fire danger events. (e.g. those above the 90th percentile value and for the definition of danger levels/classes (with level thresholds adapted to the observed/reanalysis distributions.

J. Bedia

2012-03-01

322

Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability  

International Nuclear Information System (INIS)

Graphical abstract: Plot of cos ? versus temperature for metal and ceramic surfaces where cos ? rises linearly with increase in temperature. Highlights: ? cos ? of olive oil on different surface materials rises linearly with increase in temperature. ? Slopes are much higher for quasicrystalline and polymers than for ceramics. ? Increase in surface roughness and surface flaws increases surface wettability. ? Contact angle values gave information for grouping easy-clean polymers from other materials. ? Contact angle measurements cannot directly estimate the cleanability of a surface. - Abstract: The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25–200 °C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO2), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos ? values. Studies of the effectes. Studies of the effect of roughness and surface flaws on wettability revealed that the cos ? values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability.

323

Effect of Different Calcium Concentration in Contaminate Soil on 90S Accumulation by the Seasonal Vegetative Growth of Lettuce  

International Nuclear Information System (INIS)

Pot experiment was conducted in greenhouse at National Center for Agriculture Research and Technology Transfer (NCARTT) farm in Baqa. To establish the effect of different calcium concentration in the contaminated soil on the 90S accumulation by the seasonal vegetative growth of lettuce. The pots were distributed in split plot in RCBD design with four replicates. The main plots of experiment were four concentration of calcium (Ca++) in the soil. The calcium soluble solution was applied and mixed with the soil. Four concentrations of calcium were 50, 100, 150 and 200 mg Ca /Kg. The sub main plots of experiment were four specific activities of Strontium-90. The contamination has been done with 90S to the surface area of the soil after one week of planting. The specific activities of 90S were: 40, 57, 73 and 89 Bq/Kg soil . The results indicate after 70 days of planting (duration of season), that the specific active of 90Sr in vegetative mass of plant (Lettuce) and in leached irrigation water at the end of season was nonsignificant increased with the increment of Ca concentration in the soil . The specific active of 90Sr reached to 1.12 Bq/Kg in plant and to 1.13 Bq/ l in irrigation water. There was strong linear correlation between specific active of 90Sr in vegetative mass of plant (Lettuce) with the increment of Ca concentration in the soil (r2= 94) , the similar results was observed for irrigthe similar results was observed for irrigation water (r2=88) . The distribution of specific active of 90Sr in the soil, plant and irrigation water was not significant effected by the increasing of specific active of 90Sr in contaminated soil and / or by increasing of Ca concentration in the soil. It was found that most of specific active of 90Sr in all treatments were remained at the end of season in the soil (96.6-97.9%). The values of Stander Transfer Factor (TFs) for 90Sr by plant or irrigation water weren't effected with increasing of specific active of 90Sr in the soil .On contrary the increasing of Ca concentration in the soil effectuate nonsignificant decreased of TFs by plant and irrigation water. The decreased in values of TFs were ranged from 0.010 to 0.018. (authors)

324

Vegetation-atmosphere-soil nutrient feedbacks in the Amazon for different deforestation scenarios  

Science.gov (United States)

In recent decades, large areas of the Amazon forest have been deforested and the rainforest's future may be dependent on climate and soil nutrient feedbacks associated with deforestation. This is a two-way biosphere-atmosphere interaction problem: the response of the regional climate system to the land cover varies with the forest growth, which, in turn, depends on climate and nutrient stress. Nutrient stress also varies with forest age, being most severe for young forests and declining as forests mature. Here we use a coupled climate-biosphere model to investigate how these feedbacks interact to control the secondary forest recovery after different deforestation scenarios, looking for a threshold of deforestation that could cause dangerous interference on the Amazon recovery. Results show that the reduction in rainfall is proportional to the amount of deforestation and is more drastic when the deforested area is higher than 40% of the original forest extent. In addition, this simulated precipitation reduction alone is not sufficient to prevent the rainforest regrowth. However, when the precipitation reduction is associated with a soil nutrient stress, a savannization process may start over southern Amazonia (northern Mato Grosso state), no matter how much is deforested. In this region, a large precipitation reduction in the transition from the dry to the rainy season and an increase in the dry season duration are favorable to the savanna maintenance on nutrient-limited simulations. These results may be a valuable tool for prioritizing forest conservation in this region, which presently has the highest clearing rate in Amazonia.

Senna, MôNica Carneiro Alves; Costa, Marcos Heil; Pires, Gabrielle Ferreira

2009-02-01

325

Chemical composition and antioxidant activity in different tissues of brassica vegetables.  

Science.gov (United States)

This research was conducted to evaluate glucosinolate profiles, vitamin C, total phenol, total flavonoid, and free sugar (glucose, fructose, and sucrose) content, fatty acid composition, and antioxidant activity in floret and leaf of six cauliflower and broccoli cultivars. The level of chemical constituents as well as antioxidants significantly varied among crop types, cultivars, and their different parts, in that phytochemicals such as glucosinolate were statistically higher in florets compared with leaves in both broccoli and cauliflower cultivars. In contrast, total flavonoid and free sugar were found at higher levels in the leaf parts. The Asia purple cultivar exhibited statistically higher vitamin C (649.7 mg·100 g-1), total phenol (1345.2 mg·GAE 100 g-1), and total flavonoid (632.7 mg·CE 100 g-1) contents and consequently had the highest antioxidant activity (1.12 mg·mL-1) in its florets, while Baeridom and Bridal had the highest total glucosinolate (9.66 µmol·g-1) and free sugar (318.6 mg·g-1) contents, respectively compared with other cultivars. Likewise, the major fatty acids were palmitic (23.52%-38.42%), linoleic (13.09%-18.97%), and linolenic (26.32%-51.80%) acids, which comprised the highest compositional ratio (more than 50%) of polyunsaturated fatty acids (PUFAs) in most cultivars. Among the antioxidants, total phenol exhibited the most significant positive correlation (r = 0.698 **) with antioxidant activity, followed by vitamin C (r = 0.522 **) and total flavonoid (r = 0.494 **), indicating their significant contributions to total antioxidant activity. PMID:25591122

Bhandari, Shiva Ram; Kwak, Jung-Ho

2015-01-01

326

Chemical Composition and Antioxidant Activity in Different Tissues of Brassica Vegetables  

Directory of Open Access Journals (Sweden)

Full Text Available This research was conducted to evaluate glucosinolate profiles, vitamin C, total phenol, total flavonoid, and free sugar (glucose, fructose, and sucrose content, fatty acid composition, and antioxidant activity in floret and leaf of six cauliflower and broccoli cultivars. The level of chemical constituents as well as antioxidants significantly varied among crop types, cultivars, and their different parts, in that phytochemicals such as glucosinolate were statistically higher in florets compared with leaves in both broccoli and cauliflower cultivars. In contrast, total flavonoid and free sugar were found at higher levels in the leaf parts. The Asia purple cultivar exhibited statistically higher vitamin C (649.7 mg·100 g?1, total phenol (1345.2 mg·GAE 100 g?1, and total flavonoid (632.7 mg·CE 100 g?1 contents and consequently had the highest antioxidant activity (1.12 mg·mL?1 in its florets, while Baeridom and Bridal had the highest total glucosinolate (9.66 µmol·g?1 and free sugar (318.6 mg·g?1 contents, respectively compared with other cultivars. Likewise, the major fatty acids were palmitic (23.52%–38.42%, linoleic (13.09%–18.97%, and linolenic (26.32%–51.80% acids, which comprised the highest compositional ratio (more than 50% of polyunsaturated fatty acids (PUFAs in most cultivars. Among the antioxidants, total phenol exhibited the most significant positive correlation (r = 0.698 ** with antioxidant activity, followed by vitamin C (r = 0.522 ** and total flavonoid (r = 0.494 **, indicating their significant contributions to total antioxidant activity.

Shiva Ram Bhandari

2015-01-01

327

Nitrogen–use efficiency in different vegetation type at Cikaniki Research Station, Halimun-Salak Mountain National Park, West Java  

Directory of Open Access Journals (Sweden)

Full Text Available A research about nitrogen–use efficiency (NUE and trees identification was conducted at different vegetation type at Cikaniki, Halimun-Salak National Park, West Java. Plot quadrate methods (20 x 50 m was used to analyze trees vegetation and Kjeldahl methods was used to analyze leaf nitrogen. The width and length of the leaf was also measured to obtain the leaf surface area. The result showed that there are 61 individual trees which consisted of 24 species was identified. The species which have 5 highest important value are Altingia excelsa (64,657, Castanopsis javanica (39,698, Platea latifolia (27,684, Garcinia rostrata (21,151, and Schima walichii (16,049. Futhermore Eugenia lineata (13,967, Melanochyla caesa (12,241, Quercus lineata (10,766, platea excelsa (10,766 have lower important value. Other trees have important value less than 10. Morphological and nitrogen content analyze were done on 4 species : Quercus lineata, G. rostrata, A. excelsa, and E. lineata. Among them, Quercus lineata has highest specific leaf area (SLA (0,01153, followed by G. rostrata (0,00821, A. excelsa (0,00579, and E. lineata (0,00984 g/cm2. The highest number of stomata was found on A. excelsa (85,10/mm2, followed by E. lineata (74,40/mm2, Q. lineata (53,70/mm2, and G. rostrata (18,4 /mm2. The emergent species (A. excelsa and Q. lineata have higher nitrogen content than the underlayer species (G. rostrata and E. lineata. A. excelsa have highest nitrogen use efficiency (28,19% compare to E. lineata (23,81% , Q. lineata (19,09%, and G. rostrata (14,87%. Although not significant, emergen species have higher NUE than underlayer species.

SUHARNO

2007-10-01

328

Ingestion, enzymatic digestion and absorption of particles derived from different vegetal sources by the cockle Cerastoderma edule  

Science.gov (United States)

Ingestion, enzymatic digestion and absorption of particulate detrital matter derived from six different vegetal sources by the common cockle Cerastoderma edule was analyzed in a series of seasonal experiments performed in March, May and October 2005. Two green macroalgae: Ulva lactuca and Enteromorpha sp; two vascular plants: Spartina maritima and Juncus maritimus, the red macroalgae Gracilaria gracilis; and the microalgae Isochrysis galbana were used in experiments. Detrital matter was elaborated by freeze-drying, grinding and sieving (Ulva and Enteromorpha) and lowest to those fed the vascular plant Juncus maritimus. Recorded significant differences in enzymatic digestibility among detritus were found to explain ? 40% of differences recorded in AR, and the following regression could be fitted: AR = 0.232 (± 0.032) * Digestibility + 0,072 (± 0.015); r 2 = 0.415; F = 51.036; p Ulva and Enteromorpha was found to be significantly correlated with cellulase activity in the digestive gland, whereas digestibility of Juncus, Spartina and Gracilaria was correlated with xylanase activity. Obtained correlations are discussed in the frame of contrasting conclusions in the literature regarding the importance of detritus as a food source for bivalves.

Arambalza, U.; Urrutia, M. B.; Navarro, E.; Ibarrola, I.

2010-10-01

329

Association of Bilateral Brachial-Ankle Pulse Wave Velocity Difference with Peripheral Vascular Disease and Left Ventricular Mass Index  

OpenAIRE

Unequal arterial stiffness had been associated with cardiovascular risks. We investigated whether an association existed between unequal arterial stiffness indicated by bilateral brachial-ankle pulse wave velocity (baPWV) difference and ankle-brachial index (ABI), baPWV, echocardiographic parameters and interarm and interankle systolic blood pressure (BP) differences. A total of 1111 patients referred for echocardiographic examination were included in this study. The BPs, ABI and baPWV were m...

Su, Ho-ming; Lin, Tsung-hsien; Hsu, Po-chao; Lee, Wen-hsien; Chu, Chun-yuan; Chen, Szu-chia; Lee, Chee-siong; Voon, Wen-chol; Lai, Wen-ter; Sheu, Sheng-hsiung

2014-01-01

330

Nonlinear intersubband absorption and refractive index change in n-type ?-doped GaAs for different donor distributions  

Science.gov (United States)

In this study, both the linear and nonlinear intersubband optical absorption coefficients and the refractive index changes are calculated for the uniform, triangular and Gaussian-like donor distribution. The Gaussian-like distribution differs from the Gaussian distribution other authors use. The electronic structure of n-type Si ?-doped GaAs has been theoretically calculated by solving the Schrödinger and Poisson equations self-consistently. Our results show that the location and the size of the linear and total absorption coefficients and refractive index changes depend on the donor distribution type. The shape of ?-effective potential profile and the subband properties are changed as dependent on the donor distribution model. Therefore, the variation of the absorption coefficients and refraction index changes, which can be appropriate for various optical modulators and infrared optical device applications can be smooth obtained by the alteration donor distribution model.

Ozturk, Emine

2015-01-01

331

Automatic Assessment of Global Craniofacial Differences between Crouzon mice and Wild-type mice in terms of the Cephalic Index  

DEFF Research Database (Denmark)

This paper presents the automatic assessment of differences between Wild-Type mice and Crouzon mice based on high-resolution 3D Micro CT data. One factor used for the diagnosis of Crouzon syndrome in humans is the cephalic index, which is the skull width/length ratio. This index has traditionally been computed by time-consuming manual measurements that prevent large-scale populational studies. In this study, an automatic method to estimate cephalic index for this mouse model of Crouzon syndrome is presented. The method is based on constructing a craniofacial atlas of Wild-type mice and then registering each mouse to the atlas using affine transformations. The skull length and width are then measured on the atlas and propagated to all subjects to obtain automatic measurements of the cephalic index. The registration accuracy was estimated by RMS landmark errors. Even though the accuracy of landmark matching is limited using only affine transformations, the errors were considered acceptable. The automatic estimation of the cephalic index was in full agreement with the gold standard measurements. Discriminant analysis of the three scaling parameters resulted in a good classification of the mouse groups.

Ólafsdóttir, Hildur; Oubel, Estanislao

2006-01-01

332

Impersonality of the Connectivity Index and Recomposition of Topological Indices According to Different Properties  

Directory of Open Access Journals (Sweden)

Full Text Available The connectivity index χ can be regarded as the sum of bond contributions. Inthis article, boiling point (bp-oriented contributions for each kind of bond are obtainedby decomposing the connectivity indices into ten connectivity character bases and thendoing a linear regression between bps and the bases. From the comparison of bp-orientedcontributions with the contributions assigned by χ, it can be found that they are verysimilar in percentage, i.e. the relative importance of each particular kind of bond is nearlythe same in the two forms of combinations (one is obtained from the regression withboiling point, and the other is decided by the constructor of the χ index. This coincidenceshows an impersonality of χ on bond weighting and may provide us another interpretationof the efficiency of the connectivity index on many quantitative structure–activity/property relationship (QSAR or QSPR results. However, we also found that χ’sweighting formula may not be appropriate for some other properties. In fact, there is nouniversal weighting formula appropriate for all properties/activities. Recomposition ofsome topological indices by adjusting the weights upon character bases according todifferent properties/activities is suggested. This idea of recomposition is applied to thefirst Zagreb group index M1 and a large improvement has been achieved.

Yi-Zeng Liang

2004-12-01

333

Asymptotic Conditional Distribution of Exceedance Counts: Fragility Index with Different Margins  

CERN Document Server

Let $\\bm X=(X_1,...,X_d)$ be a random vector, whose components are not necessarily independent nor are they required to have identical distribution functions $F_1,...,F_d$. Denote by $N_s$ the number of exceedances among $X_1,...,X_d$ above a high threshold $s$. The fragility index, defined by $FI=\\lim_{s\

Falk, Michael

2012-01-01

334

A comparison of the environmental impact of different AOPs: risk indexes.  

Science.gov (United States)

Today, environmental impact associated with pollution treatment is a matter of great concern. A method is proposed for evaluating environmental risk associated with Advanced Oxidation Processes (AOPs) applied to wastewater treatment. The method is based on the type of pollution (wastewater, solids, air or soil) and on materials and energy consumption. An Environmental Risk Index (E), constructed from numerical criteria provided, is presented for environmental comparison of processes and/or operations. The Operation Environmental Risk Index (EOi) for each of the unit operations involved in the process and the Aspects Environmental Risk Index (EAj) for process conditions were also estimated. Relative indexes were calculated to evaluate the risk of each operation (E/NOP) or aspect (E/NAS) involved in the process, and the percentage of the maximum achievable for each operation and aspect was found. A practical application of the method is presented for two AOPs: photo-Fenton and heterogeneous photocatalysis with suspended TiO2 in Solarbox. The results report the environmental risks associated with each process, so that AOPs tested and the operations involved with them can be compared. PMID:25558859

Giménez, Jaime; Bayarri, Bernardí; González, Óscar; Malato, Sixto; Peral, José; Esplugas, Santiago

2015-01-01

335

Evaluating the Effect of Different Wheat Rust Disease Symptoms on Vegetation Indices Using Hyperspectral Measurements  

Directory of Open Access Journals (Sweden)

Full Text Available Spectral Vegetation Indices (SVIs have been widely used to indirectly detect plant diseases. The aim of this research is to evaluate the effect of different disease symptoms on SVIs and introduce suitable SVIs to detect rust disease. Wheat leaf rust is one of the prevalent diseases and has different symptoms including yellow, orange, dark brown, and dry areas. The reflectance spectrum data for healthy and infected leaves were collected using a spectroradiometer in the 450 to 1000 nm range. The ratio of the disease-affected area to the total leaf area and the proportion of each disease symptoms were obtained using RGB digital images. As the disease severity increases, so does the scattering of all SVI values. The indices were categorized into three groups based on their accuracies in disease detection. A few SVIs showed an accuracy of more than 60% in classification. In the first group, NBNDVI, NDVI, PRI, GI, and RVSI showed the highest amount of classification accuracy. The second and third groups showed classification accuracies of about 20% and 40% respectively. Results show that few indices have the ability to indirectly detect plant disease.

Davoud Ashourloo

2014-06-01

336

Regional Climate Simulations with COSMO-CLM for West Africa using three different soil-vegetation-atmosphere-transfer (SVAT) module  

Science.gov (United States)

Climate predictions on decadal timescales constitute a new field of research, closing the gap between short-term and seasonal weather predictions and long-term climate projections. Therefore, the Federal Ministry of Education and Research in Germany (BMBF) has recently funded the research program MiKlip (Mittelfristige Klimaprognosen), which aims to create a model system that can provide reliable decadal climate forecasts. Recent studies have suggested that one region with high potential decadal predictability is West Africa. Therefore, the project DEPARTURE (DEcadal Prediction of African Rainfall and ATlantic HURricanE Activity) was established within the MiKlip program to assess the feasibility and the potential added value of regional decadal climate predictions for West Africa. To quantify the potential decadal climate predictability, a multi-model approach with the three different regional climate models REMO, WRF and COSMO-CLM (CCLM) will be realized. The presented research will contribute to DEPARTURE by performing hindcast ensemble simulations with CCLM, driven by global decadal MPI-ESM-LR simulations. Thereby, one focus is on the dynamic soil-vegetation-climate interaction on decadal timescales. Recent studies indicate that there are significant feedbacks between the land-surface and the atmosphere, which might influence the decadal climate variability substantially. To investigate this connection, two different SVATs (Community Land Model (CLM), and VEG3D) will be coupled with the CCLM, replacing TERRA_ML, the standard SVAT implemented in CCLM. Thus, sensitive model parameters shall be identified, whereby the understanding of important processes might be improved. As a first step, TERRA_ML is substituted by VEG3D, a SVAT developed at the IMK-TRO, Karlsruhe, Germany. Compared to TERRA_ML, VEG3D includes an explicit vegetation layer by using a big leaf approach, inducing higher correlations with observations as it has been shown in previous studies. The coupling of VEG3D with CCLM is performed by using the OASIS3-MCT coupling software, developed by CERFACS, Toulouse, France. Results of CCLM simulations using both SVATs are analysed and compared for the DEPARTURE model domain. Thereby ERA-Interim driven CCLM simulations with VEG3D showed better agreement with observational data than simulations with TERRA_ML, especially for dense vegetaded areas. This will be demonstrated exemplarily. Additionally, results for MPI-ESM-LR driven decadal hindcast simulations (1966 - 1975) are analysed and presented.

Breil, Marcus; Panitz, Hans-Jürgen

2014-05-01

337

Response of vegetation to the 2003 European drought was mitigated by height  

Science.gov (United States)

The effects on climate of land-cover change, predominantly from the conversion of forests to crops or grassland, are reasonably well understood for low and high latitudes but are largely unknown for temperate latitudes. The main reason for this gap in our knowledge is that there are compensating effects on the energy and water balance that are related to changes in land-surface albedo, soil evaporation and plant transpiration. We analyse how vegetation height affected the response of vegetation during the 2003 European drought using precipitation data, temperature data, normalized difference vegetation index data and a new vegetation height data set obtained from the Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud and land Elevation Satellite (ICESat). At the height of the 2003 drought we find for tall vegetation a significantly smaller decrease in vegetation index and a smaller diurnal temperature (DTR) range, indicating less water stress and drought impacts on tall vegetation. Over Germany for example, 98% of significant correlations showed a smaller anomaly in vegetation index anomaly with greater height, and 95% of significant correlations showed a smaller DTR with greater vegetation height. Over France the equivalent percentages were 94 and 88%, respectively. Vegetation height is likely associated with greater rooting depth, canopy heat capacity or both. Our results suggest that land-surface models can be improved by better estimates of vegetation height and associated with this a more realistic response to drought.

Bevan, S. L.; Los, S. O.; North, P. R. J.

2014-06-01

338

Use of unmanned aircraft systems (UAS) in a multi-scale vegetation index study of arctic plant communities in Adventdalen on Svalbard  

OpenAIRE

Use of Unmanned Aircraft Systems (UAS) gives the opportunity to carry out research with a re-duced environmental footprint. Unmanned aircraft, including both fixed wing and multi rotor types (helicopters) allow us to collect very high resolution image data for vegetation mapping without the need for any personnel walking into the site and thereby potentially disturbing the sensitive Arctic ecosystems. The main aim of this project was to explore the feasibility of UAS-based vegetation mapping ...

Tømmervik, Hans; Karlsen, Stein-rune; Nilsen, Lennart; Johansen, Bernt; Storvold, Rune; Zmarz, Anna; Beck, Pieter S.; Høgda, Kjell Arild; Goetz, Scott; Park, Taejin; Zagajewski, Bogdan; Myneni, Ranga B.; Bjerke, Jarle W.

2014-01-01

339

Body mass index in young children and allergic disease: gender differences in a longitudinal study.  

OpenAIRE

BACKGROUND: The increase in allergic diseases has occurred in parallel with the obesity epidemic, suggesting a possible association. OBJECTIVE: We investigated the relationship of body mass index (BMI) up to age 8 years with allergic disease within a birth cohort. METHODS: Children were followed from birth and were reviewed at age 3, 5 and 8 years (n=731; male 406). Parents completed questionnaires; children were weighed, measured, skin prick tested and examined. RESULTS: Increasing BMI at 3,...

Murray, Cs; Canoy, D.; Buchan, I.; Woodcock, A.; Simpson, A.; Custovic, A.

2011-01-01

340

Comparison of different ground techniques to map leaf area index of Norway spruce forest canopy.  

Czech Academy of Sciences Publication Activity Database

2007 - (Schaepman, M.; Liang, S.; Groot, N.; Kneubühler, M.) ISSN 1682-1777. - (Intl. Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 36). [10th Intl. Symposium on Physical Measurements and Spectral Signatures in Remote Sensing. Davos (CH), 12.03.2007-14.03.2007] Institutional research plan: CEZ:AV0Z60870520 Keywords : leaf area index * sampling strategy * PCA LAI-2000 * TRAC * hemispherical photograph * Norway spruce Subject RIV: GK - Forestry

Homolová, Lucie; Malenovský, Zbyn?k; Hanuš, Jan; Tomášková, Ivana; Dvo?áková, Marcela; Pokorný, Radek

341

Differences in Dietary Patterns among College Students According to Body Mass Index  

Science.gov (United States)

Objective and Participants: The authors surveyed 557 undergraduate students aged 18-56 years to assess weight status, health behaviors, and dietary variety. Methods: They used body mass index (BMI) to divide students into 4 weight categories: underweight (BMI less than 19 kg/m2), healthy weight (19 kg/m2 to 24.99 kg/m2), overweight (25 kg/m2 to…

Brunt, Ardith; Rhee, Yeong; Zhong, Li

2008-01-01

342

Assessment of metal availability to vegetation (Betula pendula) in Pb-Zn ore concentrate residues with different features  

International Nuclear Information System (INIS)

In this work, characterisation of several ore concentrate remains from an abandoned Pb-Zn mining factory was performed determining chemical and physical properties such as pH, organic carbon content, particle size distribution, total heavy metal content (Pb, Zn, Cu, As and Cd) as well as mineralogical composition which showed, in most cases, the oxidization of the parent ore material (mostly galena: PbS and sphalerite: ZnS) to more mobile fractions as anglesite (PbSO4) and goslarite (ZnSO4). Moreover, two operational defined extraction procedures commonly used in soil and sediment studies (first and second steps of BCR procedure and DTPA extraction protocol) were applied in the different mining wastes in order to study Pb and Zn mobility and likely bioavailability to Betula pendula growing on the same mining spoils, which presents lead and zinc contents in leaves over ten times background values. - Physicochemical characteristics and mineralogy of mining tailings determine metal availability to vegetation in abandoned mining sites

343

Vegetation NDVI Linked to Temperature and Precipitation in the Upper Catchments of Yellow River  

OpenAIRE

Vegetation in the upper catchment of Yellow River is critical for the ecological stability of the whole watershed. The dominant vegetation cover types in this region are grassland and forest, which can strongly influence the eco-environmental status of the whole watershed. The normalized difference vegetation index (NDVI) for grassland and forest has been calculated and its daily correlation models were deduced by Moderate Resolution Imaging Spectroradiometer products on 12 dates in 2000, 200...

Hao, F.; Zhang, X.; Ouyang, W.; Skidmore, A. K.; Toxopeus, A. G.

2012-01-01

344

Recent Declines in Warming and Vegetation Greening Trends over Pan-Arctic Tundra  

OpenAIRE

Vegetation productivity trends for the Arctic tundra are updated for the 1982–2011 period and examined in the context of land surface temperatures and coastal sea ice. Understanding mechanistic links between vegetation and climate parameters contributes to model advancements that are necessary for improving climate projections. This study employs remote sensing data: Global Inventory Modeling and Mapping Studies (GIMMS) Maximum Normalized Difference Vegetation Index (MaxNDVI), Special Senso...

Polyakov, Igor V.; Tucker, Compton J.; Pinzon, Jorge E.; Epstein, Howard E.; Comiso, Josefino C.; Bieniek, Peter A.; Walker, Donald A.; Raynolds, Martha K.; Bhatt, Uma S.

2013-01-01

345

Using the Normalized Difference Water Index (NDWI within a Geographic Information System to Detect Swimming Pools for Mosquito Abatement: A Practical Approach  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito-borne diseases affect millions of people worldwide. In the United States, since 1999, West Nile Virus (WNV has infected 36,801 people and has caused the deaths of 1,580. In California, since 2002, nearly 3,600 people have been infected with WNV with an additional 124 fatalities. Analyses of remotely- and spatially-based data have proven to facilitate the study of mosquito-borne diseases, including WNV. This study proposes an efficient procedure to identify swimming pools that may serve as potential mosquito habitat. The procedure derives the Normalized Difference Water Index (NDWI from high resolution, multi-spectral imagery to detect the presence of surface water, and then incorporates vector-based data layers within a GIS to identify residential land parcels with detectable water. This study compared the parcels identified as having water (535 with parcels known to have swimming pools (682 resulting in an accuracy of 78.4%. Nineteen of the 147 land parcels with swimming pools had backyards with enough vegetation to obscure the presence of a swimming pool from the satellite. The remaining 128 parcels lacked enough surface water for the NDWI to indicate them as actually having surface water. It is likely then that swimming pools, associated with such parcels, may have enough water in them to provide adequate habitat for mosquitoes, and so field inspection by mosquito abatement personnel would be justified.

Stuart K. McFeeters

2013-07-01

346

Post-fire vegetation recovery in Portugal based ewline on spot/vegetation data  

Directory of Open Access Journals (Sweden)

Full Text Available A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI, with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

C. Gouveia

2010-04-01

347

Post-fire vegetation recovery in Portugal based on spot/vegetation data  

Science.gov (United States)

A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

2010-04-01

348

Glycemic index differences of high-fat diets modulate primarily lipid metabolism in murine adipose tissue.  

Science.gov (United States)

A low vs. high glycemic index of a high-fat (HF) diet (LGI and HGI, respectively) significantly retarded adverse health effects in adult male C57BL/6J mice, as shown recently (Van Schothorst EM, Bunschoten A, Schrauwen P, Mensink RP, Keijer J. FASEB J 23: 1092-1101, 2009). The LGI diet enhanced whole body insulin sensitivity and repressed HF diet-induced body and white adipose tissue (WAT) weight gain, resulting in significantly reduced serum leptin and resistin levels and increased adiponectin levels. We questioned how WAT is modulated and characterized the molecular mechanisms underlying the glycemic index-mediated effects using whole genome microarrays. This showed that the LGI diet mainly exerts its beneficial effects via substrate metabolism, especially fatty acid metabolism. In addition, cell adhesion and cytoskeleton remodeling showed reduced expression, in line with lower WAT mass. An important transcription factor showing enhanced expression is PPAR-?. Furthermore, serum levels of triglycerides, total cholesterol, and HDL- and LDL-cholesterol were all significantly reduced by LGI diet, and simultaneously muscle insulin sensitivity was significantly increased as analyzed by protein kinase B/Akt phosphorylation. Cumulatively, even though these mice were fed an HF diet, the LGI diet induced significantly favorable changes in metabolism in WAT. These effects suggest a partial overlap with pharmacological approaches by thiazolidinediones to treat insulin resistance and statins for hypercholesterolemia. It is therefore tempting to speculate that such a dietary approach might beneficially support pharmacological treatment of insulin resistance or hypercholesterolemia in humans. PMID:21673076

van Schothorst, Evert M; Bunschoten, Annelies; Verlinde, Eline; Schrauwen, Patrick; Keijer, Jaap

2011-08-16

349

Assessment of metals contamination in Klang River surface sediments by using different indexes  

Directory of Open Access Journals (Sweden)

Full Text Available Surface sediments (0-5 cm from 21 stations throughout Klang River were sampled for metal concentration as well sediment's pH, total organic carbon (TOC and particles sizes to obtain an overall classification of metal contaminations in the area. The concentration of metals (µg?g, Fe%, dw were as follows: 0.57- 2.19 Cd; 31.89-272.33 Zn; 5.96-24.47 Ni; 10.57- 52.87 Cu; 24.23-64.11 Pb and 1.56-3.03 Fe. The degree of sediment contaminations were computed using an enrichment factor (EF and geoaccumulation index (Igeo. The results suggested that enrichment factor and geoaccumulation values of Cd were greatest among the studied metals. Pearson's correlation indicated that effectiveness of TOC in controlling the distribution and enrichment of metals was a more important factor than that of the grain size (< 63µm. The study revealed that on the basis of computed indexes, Klang River is classified as moderately polluted river.

Abolfazl Naji

2011-01-01

350

Exposition index calculation from different points in a gamma sterilization plant radiation room  

International Nuclear Information System (INIS)

Radiation fields produced by a JS-6500 rectangular irradiator source were evaluated. Knowledge of the values of these fields is necessary in irradiation and health physics processes. Techniques for evaluating the dose rates from puntual, linear and plane sources were applied and computer programs for the three sources designed. Fricke, cupric-ferrous and red acrilic dosimetric systems were used, to verify the eight points located along the interior walls of the irradiation room, around the source with 936, 987 Ci of Co-60 (1st-March 1980). When considering the distance between the source and each point of interest the calculated exposition indexes obtained were practically the same for the three source types and were up to 35% greater than the experimental values; in contrast when absorption and buildup of the source were taken in to account, the experimental values were higher than the calculated ones by up to 16%, this in estimating the produced exposition index for a rectangular source at least there two parameters should be included. (author)

351

Adaptación de una nueva hortaliza (Cucurbita pepo var. vegetable spaghetti) a diferentes condiciones de cultivo / Adaptation of a new vegetable (Curcurbita pepo var. vegetable spaghetti) to different growing conditions  

Scientific Electronic Library Online (English)

Full Text Available El cultivo de zapallo spaghetti constituye una nueva alternativa productiva que ha despertado el interés de los consumidores argentinos por sus virtudes. El objetivo de este estudio fue el de investigar la influencia de la densidad y fecha de siembra en el cultivo de zapallo spaghetti. El mismo se l [...] levó a cabo en la Chacra Experimental de la Facultad de Agronomía, sobre la Ruta Nacional Núm. 3 km 305, en el Partido de Azul, en un suelo argiudol típico. La superficie total del mismo fue de 5,952 m². Cada parcela tenía una superficie de 88 m² y estaba constituida por cuatro surcos distanciados a 2 m entre sí y 11 m de largo, habiéndose evaluado los dos surcos centrales. Se trabajó con dos fechas de siembra: 10 y 24 de noviembre y con cuatro densidades: 0.25; 0.5; 0.75 y 1 m entre pl. 20,000; 15,000; 10,000 y 5,000 planta·ha-1. La siembra se realizó manualmente. Se fertilizó en banda en presiembra y se efectuó control químico preventivo de malezas con Naptalam en la línea de siembra y con Trifluralina incorporada con motocultivador en los entresurcos. Se analizaron los datos obtenidos bajo un modelo de parcelas divididas. Para la variable peso total de producción no se detectaron diferencias significativas para ninguno de los efectos e interacciones consideradas. Para la variable peso promedio de producción se detectaron diferencias significativas para los efectos densidad y fecha. Con las densidades de cultivo 2 y 3 se lograron la mayor cantidad de calibres intermedios (2 y 3), más adecuados a las exigencias del mercado. Abstract in english Spaghetti squash is an alternative crop with qualities that have aroused interest among Argentinean consumers. The objective of this experiment was to study the influence of sowing date and density in Cucurbita pepo var. vegetable spaghetti. The study was conducted in the experimental unit of the Fa [...] cultad de Agronomia in Azul, Argentina, in a typical argiudol soil on a total area of 5,952 m². Each plot had an area of 88 m² and comprised four 11 m rows, 2 m apart. The two middle rows were evaluated. There were two sowing dates (November 10th and 24th) and four sowing densities (0.25, 0.5, 0.75, and 1 m between plants, that is, 20 000, 15 000, 10 000 and 5000 pl·ha-1). Band fertilization as well as preventive chemical weed-control with Naptalan, on sowing line and Trifluralina between rows with a cultivator, took place at presowing. Data were analyzed under a model of divided plots, in which the main plot was biostimulants and the sub-plots density and sowing date. The interactions between main factors were also considered. No significant differences were detected for total crop weight among the effects of interaction between sowing density and date. With crop densities two and three, more medium (two and three caliber) fruits (1.05 and 1.44 kg) were obtained. These calibers are suitable for marketing.

A. M, Castagnino; P., Sastre Vázquez; K. E., Díaz; A., Menet; S., Sasale; M., Navarro Dujmovich.

2008-12-01

352

Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures  

International Nuclear Information System (INIS)

Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10-3 to 25 . 10-3) mol . kg-1. The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs

353

BODY COMPOSITION AND BODY FAT DISTRIBUTION IN ADULTS WITH DIFFERENT BODY MASS INDEX  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to determine body composition and body fat distribution in 176 adults divided according to body mass index in 4 groups: normal-weight, overweight, obese and excess obese. Absolute and relative muscle (MM, osseous (OM and peripheral fat mass (PFM were calculated by anthropometric method of Mateigka. Total fat mass (TFM was calculated by subtracting lean body mass from total body mass (TBM. Mean OM, MM and PFM were lowest in the 1st and highest in the 4th group in both genders. Females had significantly higher values for all fat components. In adults obesity is a result of increase in absolute OM and MM and highest increase of PFM and TFM. The higher TFM is a result of increasing in visceral fat mass and higher percent of increase in PFM.

Elizabeta Sivevska-Smilevska

2012-12-01

354

Transmission of Light in Crystals with different homogeneity: Using Shannon Index in Photonic Media  

CERN Document Server

Light transmission in inhomogeneous photonic media is strongly influenced by the distribution of the diffractive elements in the medium. Here it is shown theoretically that, in a pillar photonic crystal structure, light transmission and homogeneity of the pillar distribution are correlated by a simple linear law once the grade of homogeneity of the photonic structure is measured by the Shannon index, widely employed in statistics, ecology and information entropy. The statistical analysis shows that the transmission of light in such media depends linearly from their homogeneity: the more is homogeneous the structure, the more is the light transmitted. With the found linear relationship it is possible to predict the transmission of light in random photonic structures. The result can be useful for the study of electron transport in solids, since the similarity with light in photonic media, but also for the engineering of scattering layers for the entrapping of light to be coupled with photovoltaic devices.

Bellingeri, Michele; Scotognella, Francesco

2010-01-01

355

Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant  

International Nuclear Information System (INIS)

The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V5+ species from soil, vegetable and grass samples using Na2CO3 in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V5+ and V4+ determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 ?g/g in test and control soil samples, respectively. The contents of V5+ and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 ?g/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P 5+ and V4+5+ and V4+ species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

356

Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant  

Energy Technology Data Exchange (ETDEWEB)

The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V{sup 5+} species from soil, vegetable and grass samples using Na{sub 2}CO{sub 3} in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V{sup 5+} and V{sup 4+} determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 {mu}g/g in test and control soil samples, respectively. The contents of V{sup 5+} and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 {mu}g/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P < 0.01). Statistical evaluations indicate that the sum of concentrations of V{sup 5+} and V{sup 4+} species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

Khan, Sumaira, E-mail: skhanzai@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kolachi, Nida Fatima, E-mail: nidafatima6@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Qadir, E-mail: aqshah07@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kumar, Sham; Shah, Faheem [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

2011-06-15

357

Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables  

Directory of Open Access Journals (Sweden)

Full Text Available In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA and sterigmatocystin (STC. Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found in fresh salads were Cladosporium (42.89%, Penicillium (25.78%, Aspergillus (14.67% and Alternaria (6.89%. C. cladosporioides (40.44%, followed by A. niger (10.22%, P. aurantiogriseum (7.55%, A. alternata (6.89% and Fusarium spp. (3.11% were the most dominating species. Other species were represented with 2.22% (Eurotium spp., 1.56% (Botrytis spp., 0.67% (Phoma spp., 0.44% (Geotrichum spp., Mucor spp., Phialophora spp. and 0.22% (Emericella spp., Paecilomyces spp., Trichoderma spp., Xeromyces spp.. Twenty-two of 41 identified mould species were potentially toxigenic, which accounted for 46.18% of the total isolated population. The most frequent were the potential producers of ochratoxin A (17.77%. Potential producers of moniliformin were isolated in 3.11% of samples, while producers of fumonisin and STC were found in 2.67% and 2.44% of samples, respectively. The tested isolates of OA producers did not demonstrate the ability to biosynthetise this mycotoxins, but two out of five isolates of A. versicolor were found to biosynthesise STC in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate that such products may threaten human health, considering that isolated species were potentially toxigenic, while isolates of A. versicolor also biosynthesised STS.

Koci?-Tanackov Sun?ica D.

2010-01-01

358

[Analysis on vegetations spectral characteristics along the altitudinal gradients in south-facing slope of Dangxiong Valley].  

Science.gov (United States)

The present study focused on variation of vegetation types and canopy spectra along the altitudinal gradients in south-facing slope of Dangxiong valley in Tibet. Spectral extraction methods including red edge analysis and vegetation indices were used for vegetation spectral characteristics analysis. Through the hierarchical clustering analysis based on the vegetation spectral features, the feasibility of remote sensing classification of vegetation types along the elevation gradients in the experimental area was evaluated. The experimental results showed that: there were significant differences in spectral features including water index (WI), red edge POSITION (REP), and normalized difference vegetation index (NDVI) in different plots along elevation gradients in the study area, and there were strong correlations between WI and leaf water content, REP and dry biomass, NDVI and vegetation coverage. The hierarchical clustering analysis result of 12 vegetation samples along the altitudinal gradients is consistent with the ground survey, which shows that the selected vegetation spectral features can characterize the vertical distribution of vegetation types in the experimental area. The vegetation spectral analysis in this study can provide the priori knowledge support of spectral characteristics for the vegetation vertical distribution information extraction in the Tibet Plateau. PMID:23285892

Jiao, Quan-Jun; Zhang, Bing; Liu, Liang-Yun; He, Yong-Tao; Hu, Yong

2012-10-01

359

Heavy metal contamination in surface sediments of Yangtze River intertidal zone: An assessment from different indexes  

Energy Technology Data Exchange (ETDEWEB)

Surface sediments (0-5 cm) from 59 stations within the Yangtze River intertidal zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg{sup -1} dry weight): Al, 40,803-97,213; Fe, 20,538-49,627; Cd, 0.12-0.75; Cr, 36.9-173; Cu, 6.87-49.7; Mn, 413-1,112; Ni, 17.6-48.0; Pb, 18.3-44.1; and Zn, 47.6-154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes (I{sub geo}) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn. - Surface sediment metal enrichment is evidenced for Cd, Cr and Ni in the Yangtze River intertidal zone.

Zhang Weiguo [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Feng Huan, E-mail: fengh@mail.montclair.ed [Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043 (United States); Chang Jinna; Qu Jianguo; Xie Hongxia; Yu Lizhong [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China)

2009-05-15

360

Lymphocytic nucleolar index in combined application of phosphorogranic substances and different radiation factors  

International Nuclear Information System (INIS)

Sex mature male rats were treated as follows: 1) daily during four months with phosphoroorganic substances (POS) containing preparation ''Agria 1050'' with a 1/40 LD50 dose; 2) acute irradiated with X rays on three levels - 50 mGy, 250 mGy and 500 mGy; 3) intratracheally with Ce144 with activities of 37 kBg/animal and 370 kBg/animal alone or in combination with POS. The nucleolar index (NI) of the lymphocytes was determined in the first and second week after treatment. It was found that NI showed insignificant increase after treatment with POS. When applied separately X-ray irradiation increased NI, the effect being independent on the dose rates. High doses of Ce144 induced a significant increase of NI after the second week. Combined application of POS and irradiation factor caused more significant changes in NI-values. The results obtained are regarded as an early and sensitive criterion for the changes in reproductive activity of lymphoid organs or cells of the whole lymph system. (authors)

361

Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures  

Energy Technology Data Exchange (ETDEWEB)

Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10{sup -3} to 25 . 10{sup -3}) mol . kg{sup -1}. The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs.

Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: mjiqauchem@yahoo.com; Chaudhry, Mansoora Ahmed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2009-02-15

362

Avaliação do ruído através do SPBI (Statistical Pass-By Index em diferentes pavimentos Noise evaluation using the SPBI (Statistical Pass-By Index for different pavements  

Directory of Open Access Journals (Sweden)

Full Text Available O transporte rodoviário causa grande impacto no meio ambiente, tanto pelo grande consumo de energia quanto pela infra-estrutura física necessária a sua operação. A emissão de gases e os ruídos causados pelo tráfego causam danos irreversíveis ao meio ambiente e têm sido alvo de inúmeros estudos e pesquisas. Sabe-se que o atrito pneu/pavimento e as propriedades acústicas dos revestimentos influenciam de sobremaneira a geração e a propagação do ruído. Essa pesquisa tem como objetivo avaliar o ruído causado pelo tráfego de veículos em quatro diferentes pavimentos implantados em diferentes rodovias através do SPBI (Statistical Pass-By Index. A metodologia adotada seguiu as prescrições da norma ISO 11819-1, a qual determina que um decibelímetro seja instalado na lateral da via para medir o ruído máximo causado pela passagem de um veículo. O revestimento em CBUQ foi o pavimento cujas maiores medidas foram observadas (86,84dBA seguido do CCP (83,28dBA, do TSD (83,26dBA do MICRO (81,14dBA e da CPA (81,03dBA. Os resultados indicam que a escolha adequada do revestimento pode atenuar de maneira expressiva o ruído causado pelo tráfego rodoviário.Highway transportation causes immense environmental impacts, as much by the enormous use of energy as for the physical infrastructure necessary for its operation. The gas emission and traffic noise cause irreversible damages to the environment and this has been the objective of a lot of studies and researches. It is known that the contact between tire and pavement surface and the acoustic properties of the coverings influence the noise’s generation and propagation. This research aims to evaluate the noise caused by the traffic of vehicles in four different pavements through SPBI (Statistical Pass-By Index. The methodology followed the prescriptions of the norm ISO 11819-1; the decibelimeter is installed in the road side and it records the maximum noise caused by each vehicle. HMA presents higher noise measurement (86,84dBA followed by PCC (83,28dBA, ST (83,26dBA MICRO (81,14dBA and PC (81,03dBA. The results indicate that correct pavement selection can reduce, in an expressive way, the noise caused by road traffic.

Luciano Pivoto Specht

2009-12-01

363

Avaliação do ruído através do SPBI (Statistical Pass-By Index) em diferentes pavimentos / Noise evaluation using the SPBI (Statistical Pass-By Index) for different pavements  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O transporte rodoviário causa grande impacto no meio ambiente, tanto pelo grande consumo de energia quanto pela infra-estrutura física necessária a sua operação. A emissão de gases e os ruídos causados pelo tráfego causam danos irreversíveis ao meio ambiente e têm sido alvo de inúmeros estudos e pes [...] quisas. Sabe-se que o atrito pneu/pavimento e as propriedades acústicas dos revestimentos influenciam de sobremaneira a geração e a propagação do ruído. Essa pesquisa tem como objetivo avaliar o ruído causado pelo tráfego de veículos em quatro diferentes pavimentos implantados em diferentes rodovias através do SPBI (Statistical Pass-By Index). A metodologia adotada seguiu as prescrições da norma ISO 11819-1, a qual determina que um decibelímetro seja instalado na lateral da via para medir o ruído máximo causado pela passagem de um veículo. O revestimento em CBUQ foi o pavimento cujas maiores medidas foram observadas (86,84dBA) seguido do CCP (83,28dBA), do TSD (83,26dBA) do MICRO (81,14dBA) e da CPA (81,03dBA). Os resultados indicam que a escolha adequada do revestimento pode atenuar de maneira expressiva o ruído causado pelo tráfego rodoviário. Abstract in english Highway transportation causes immense environmental impacts, as much by the enormous use of energy as for the physical infrastructure necessary for its operation. The gas emission and traffic noise cause irreversible damages to the environment and this has been the objective of a lot of studies and [...] researches. It is known that the contact between tire and pavement surface and the acoustic properties of the coverings influence the noise’s generation and propagation. This research aims to evaluate the noise caused by the traffic of vehicles in four different pavements through SPBI (Statistical Pass-By Index). The methodology followed the prescriptions of the norm ISO 11819-1; the decibelimeter is installed in the road side and it records the maximum noise caused by each vehicle. HMA presents higher noise measurement (86,84dBA) followed by PCC (83,28dBA), ST (83,26dBA) MICRO (81,14dBA) and PC (81,03dBA). The results indicate that correct pavement selection can reduce, in an expressive way, the noise caused by road traffic.

Luciano Pivoto, Specht; Sérgio C., Callai; Oleg A., Khatchatourian; Raquel, Kohler.

2009-12-01

364

Effect of Four Different Vegetable Oils (Red Palm Olein, Palm Olein, Corn Oil, Coconut Oil on Antioxidant Enzymes Activity of Rat Liver  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of the study was to evaluate the effect of four different vegetable oils [Red Palm Olein (RPO, Palm Olein (PO, Corn Oil (CO, Coconut Oil (COC] on antioxidant enzymes activity of rat liver. Sixty six Sprague Dawley male rats which were randomly divided into eleven groups of 6 rats per group and were treated with 15% of RPO, PO, CO and COC for 4 and 8 weeks. Rats in the control group were given normal rat pellet only while in treated groups, 15% of additional different vegetable oils were given. After 4 weeks of treatment the Catalase (CAT activity results showed that there was no significance difference (p=0.05 between the control group and treated groups while after 8 weeks of treatment showed that there was no significant different (p=0.05 between control group and RPO group but the treated rat liver with PO, CO and COC groups were the lowest and it were significantly lower (p=0.05 than control group. For Superoxide Dismutase (SOD there was no significance difference (p=0.05 between the control group and treated groups of vegetable oils after 4 and 8 weeks of treatment. Thus the study indicated that there was no significant (p=0.05 effect on antioxidant enzyme (superoxide dismutase but there was significant effect (p=0.05 on catalase in rat liver.

Aminah Abdullah

2011-01-01

365

A Vegetation Index to Estimate Terrestrial Gross Primary Production Capacity for the Global Change Observation Mission-Climate (GCOM-C)/Second-Generation Global Imager (SGLI) Satellite Sensor  

OpenAIRE

To estimate global gross primary production (GPP), which is an important parameter for studies of vegetation productivity and the carbon cycle, satellite data are useful. In 2014, the Japan Aerospace Exploration Agency (JAXA) plans to launch the Global Change Observation Mission-Climate (GCOM-C) satellite carrying the second-generation global imager (SGLI). The data obtained will be used to estimate global GPP. The rate of photosynthesis depends on photosynthesis reduction and photosynthetic ...

Juthasinee Thanyapraneedkul; Kanako Muramatsu; Motomasa Daigo; Shinobu Furumi; Noriko Soyama; Kenlo Nishida Nasahara; Hiroyuki Muraoka; Noda, Hibiki M.; Shin Nagai; Takahisa Maeda; Masayoshi Mano; Yasuko Mizoguchi

2012-01-01

366

Estimates of boreal forest vegetation rate based on electromagnetic radiation  

International Nuclear Information System (INIS)

Complete text of publication follows. Applications of electromagnetic methods have greatly enhanced ability to monitor and manage in the areas of forestry. Accurate measurements of regional and global scale vegetation dynamics (phenology) are required to improve models and understanding of inter-annual variability in terrestrial ecosystem carbon exchange and climate-biosphere interactions. Study of vegetation phenology is required for understanding of variability in ecosystem. Remote sensing of the Earth traditionally has used reflected energy in the visible and infrared and emitted energy in the thermal infrared and microwave regions to gather radiation that can be analyzed numerically or used to generate images whose tonal variations represent different intensities of photons associated with a range of wavelengths that are received at the sensor. This sampling of a (continuous or discontinuous) range(s) of wavelengths is the essence of what is usually termed multispectral remote sensing. In this paper, monitoring of vegetation dynamics using remote sensing of the Earth is presented. Vegetation variability (vegetation rate) in different climatic areas is investigated. Original software using IDL interactive language for processing of satellite long-term data series was developed. To investigate growth dynamics vegetation rate inferred from remote sensing was used. All estimations based on annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS) imation Imaging Spectroradiometer (MODIS) imagery. Vegetation rate for Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI) was calculated using MODIS data. Time series covers 9 years, from 2000 to 2008. Comparison of EVI and NDVI derived growth rates has shown that NDVI derived rates reveal spatial structure better. Using long-term data of vegetation rates variance was estimated that helps to reveal areas with anomalous growth rate. Such estimation shows sensitivity degree of different areas to climatic changes. It was shown that vegetation rate anomaly depends not only on species structure but also on growth conditions. Woods of heights depend on climatic variability unlike woods of lowlands. Principal components analysis shows vegetation with different rate conditions. Also it reveals vegetation of same type in areas with different conditions. It was demonstrated that using of remote sensing is able to monitor vegetation phenology with good success.

367

STUDY OF SACRAL INDEX: COMPARISON BETWEEN DIFFERENT REGIONAL POPULATIONS OF INDIA AND ABROAD  

OpenAIRE

Identification of sex by human skeletal remains is a critical problem and is very important in anthropological and medico legal works. Bones often survive the process of decay and therefore provide the major evidence of human age and sex after death. Over the years different authors had carried various types of measurements on human sacra of different races and regions. The present study carried out 81 sacra of unknown sex contains 45 male and 36 female sacra identified by physical characteri...

Poornima Janipati; Jyothinath Kothapalli; Shamsunder Rao V

2014-01-01

368

Stability of potato chip fried in vegetable oils with different degree of unsaturation. Effect of ascorbyl palmitate during storage  

Directory of Open Access Journals (Sweden)

Full Text Available Four vegetable oils with different polyunsaturated/saturated fatty acid ratio (P/S: 5.2 for sunflower oil, 3.,4 for canola rapeseed oil, 0.4 for a blend of palm oleic and canola rapeseed oil (80:20, and 0.3 for palm olein were assayed for stability of crisps fried in these oils during storage at 60º C. The action of ascorbyl palmitate with special attention to its synergistic effect on the natural antioxidants was also tested. by addition to the fried potatoes. The evolution of the oxidative stability was measured through peroxide value, quantitation of tocopherols and tocotrienols, and induction time (IT by means of Rancimat. Oil degradation during frying was very low as both polar compound percentages and natural antioxidant had similar levels to those present in refined oils. Evolution of analytical parameters during storage results indicated that oil unsaturation degree or P/S had a much more importance on stability of the product than had the content and type of natural antioxidants and the addition of AP. Nevertheless, addition of AP to the fried potatoes had a significant effect resulting in higher retention of natural antioxidants, higher IT and lower PV at any storage timeSe estudia la evolución de la oxidación a 60º C en patatas fritas con cuatro aceites vegetales de distinta relación ácidos grasos poliinsaturados/saturados (P/S: 5,4 para el aceite de girasol, 3,4 para el aceite de canola, 0,4 para una mezcla de oleína de palma (80 % y aceite de canola (20 % y 0,3 para la oleína de palma. Se estudia igualmente la influencia de la adición de palmitato de ascorbilo (AP durante la conservación del producto frito con especial atención a su efecto sinergista sobre los antioxidantes naturales. La evolución de la oxidación en lotes de patatas, con y sin adición de AP, se determinó mediante las siguientes determinaciones analíticas: índice de peróxidos (PV, cuantificación de tocoferoles y tocotrienoles, y periodos de inducción (IT en Rancimat. La degradación de los aceites durante el proceso de fritura fue muy baja puesto que los niveles de compuestos polares y de antioxidantes naturales fueron similares a los encontrados en aceites refinados. La evolución de los índices analíticos durante el almacenamiento mostraron la importancia primordial del grado de insaturación del aceite por encima de la cantidad y tipo de antioxidantes y de la adición de AP. Sin embargo, la adición de AP a las patatas fritas tuvo un claro efecto sinergista traducido en menores PV y mayores cantidades de antioxidantes naturales e IT para cualquier tiempo de almacenamiento.

Torres, R.

2002-06-01

369

Cognitive strategy use as an index of developmental differences in neural responses to feedback.  

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Developmental differences in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and superior parietal cortex (SPC) activation are associated with differences in how children, adolescents, and adults learn from performance feedback in rule-learning tasks (Crone, Zanolie, Leijenhorst, Westenberg, & Rombouts, 2008). Both maturational differences and performance differences can potentially explain variance in functional brain activation. To disentangle those effects, we established strategy differences in the performance of participants on the task of Crone et al. (2008) by the application of latent mixture models (McLachlan & Peel, 2000). We found 4 categorically different strategies, which were divided across age groups. Both adults and adolescents were distributed among all strategy groups except for the worst performing one, whereas children were distributed among all strategy groups except for the best performing one. Strategy use was a mediator and largely explained the relation between age and variance in activation patterns in the DLPFC and the SPC but not in the ACC. These findings are interpreted vis-à-vis age versus performance predictors of brain development. PMID:25329556

Andersen, Lau M; Visser, Ingmar; Crone, Eveline A; Koolschijn, P Cédric M P; Raijmakers, Maartje E J

2014-12-01

370