WorldWideScience

Sample records for vegetation induced variations

  1. Groundwater recharge - climatic and vegetation induced variations. Simulations in the Emaan and Aespoe areas in southern Sweden

    International Nuclear Information System (INIS)

    Losjoe, K.; Johansson, Barbro; Bringfelt, B.; Oleskog, I.; Bergstroem, S.

    1999-01-01

    Climate change and man-made interference will cause an impact on runoff and groundwater recharge in the future. With the aim to give a conception of seasonal variations and the magnitude of the differences, the HBV model has been used as a tool for simulating five climate alternatives in two areas of south-east Sweden. The climate alternatives include both increased and decreased temperature and precipitation. These are not predictions of a future climate change, and should only be regarded as examples. The purpose has been to exemplify a conceivable magnitude of change during temperate/boreal conditions. It has not been within the scope of this report to evaluate the most probable climate change scenarios. The impacts of different climate scenarios on the total groundwater recharge and the deep groundwater recharge have been calculated as long-term mean values and are presented in comparison with model-simulated values with an actual (recorded) climate sequence. The results show great differences between the climate alternatives. An increase in temperature will decrease snow accumulation and increase the evapotranspiration and can totally extinguish the spring snowmelt peak in runoff and groundwater recharge. A decreased temperature, on the contrary, will imply decreased winter runoff and recharge values and an increase in spring and summer values. Evapotranspiration and soil water content play a key role in the runoff and recharge processes. This report makes a review of some literature about work done within the areas of investigation and calculation of evapotranspiration. Research is in progress, not only on formulating future climate scenarios, but also on distinguishing evapotranspiration from different kinds of vegetation. These are complex questions, but vital ones, as a climate change will also affect the vegetation. Until new research results are presented, well-known methods can be used for simulating the effects of logging on runoff and groundwater

  2. Application of Satellite Solar-Induced Chlorophyll Fluorescence to Understanding Large-Scale Variations in Vegetation Phenology and Function Over Northern High Latitude Forests

    Science.gov (United States)

    Jeong, Su-Jong; Schimel, David; Frankenberg, Christian; Drewry, Darren T.; Fisher, Joshua B.; Verma, Manish; Berry, Joseph A.; Lee, Jung-Eun; Joiner, Joanna

    2016-01-01

    This study evaluates the large-scale seasonal phenology and physiology of vegetation over northern high latitude forests (40 deg - 55 deg N) during spring and fall by using remote sensing of solar-induced chlorophyll fluorescence (SIF), normalized difference vegetation index (NDVI) and observation-based estimate of gross primary productivity (GPP) from 2009 to 2011. Based on GPP phenology estimation in GPP, the growing season determined by SIF time-series is shorter in length than the growing season length determined solely using NDVI. This is mainly due to the extended period of high NDVI values, as compared to SIF, by about 46 days (+/-11 days), indicating a large-scale seasonal decoupling of physiological activity and changes in greenness in the fall. In addition to phenological timing, mean seasonal NDVI and SIF have different responses to temperature changes throughout the growing season. We observed that both NDVI and SIF linearly increased with temperature increases throughout the spring. However, in the fall, although NDVI linearly responded to temperature increases, SIF and GPP did not linearly increase with temperature increases, implying a seasonal hysteresis of SIF and GPP in response to temperature changes across boreal ecosystems throughout their growing season. Seasonal hysteresis of vegetation at large-scales is consistent with the known phenomena that light limits boreal forest ecosystem productivity in the fall. Our results suggest that continuing measurements from satellite remote sensing of both SIF and NDVI can help to understand the differences between, and information carried by, seasonal variations vegetation structure and greenness and physiology at large-scales across the critical boreal regions.

  3. Simulating sub-Milankovitch climate variations associated with vegetation dynamics

    Directory of Open Access Journals (Sweden)

    E. Tuenter

    2007-01-01

    Full Text Available Climate variability at sub-Milankovitch periods (between 2 and 15 kyr is studied in a set of transient simulations with a coupled atmosphere/ocean/vegetation model of intermediate complexity (CLIMBER-2. Focus is on the region influenced by the African and Asian summer monsoon. Pronounced variations at periods of about 10 kyr (Asia and Africa and about 5 kyr (Asia are found in the monsoonal runoff in response to the precessional forcing. In the model this is due to the following mechanism. For low summer insolation (precession maximum precipitation is low and desert expands at the expense of grass, while for high insolation (precession minimum precipitation is high and the tree fraction increases also reducing the grass fraction. This induces sub-Milankovitch variations in the grass fraction and associated variations in the water holding capacity of the soil. The runoff does not exhibit sub-Milankovitch variability when vegetation is kept fixed. High-latitude vegetation also exhibits sub-Milankovitch variability under both obliquity and precessional forcing. We thus hypothesize that sub-Milankovitch variability can occur due to the dynamic response of the vegetation. However, this mechanism should be further tested with more sophisticated climate/vegetation models.

  4. Impact of dam-induced hydrological changes on riparian vegetation

    Science.gov (United States)

    Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

    2010-05-01

    Hydrological disturbances are a key factor for the riparian vegetation, which is a highly dynamic ecosystem prone to external forcing. Random fluctuations of water stages drive in fact the alternation of periods of floods and exposure of the vegetated plots. During flooding, the plots are submerged and vegetation is damaged by burial, uprooting and anoxia, while during exposure periods vegetation grows according to the soil moisture content and the phreatic water table depth. The distribution of vegetation along the riparian transect is then directly connected to the stochasticity of river discharges. River damming can have remarkable impacts on the hydrology of a river and, consequently, on the riparian vegetation. Several field studies show how the river regulation induced by artificial reservoirs can greatly modify the statistical moments and the autocorrelation of the discharge time series. The vegetation responds to these changes reducing its overall heterogeneity, declining - substituted by exotic species - and shifting its starting position nearer or far away from the channel center. These latter processes are known as narrowing and widening, respectively. In our work we explore the effects of dam-induced hydrological changes on the narrowing/widening process and on the total biomass along the transect. To this aim we use an eco-hydrological stochastic model developed by Camporeale and Ridolfi [2006], which is able to give a realistic distribution of the biomass along the transect as a function of a few hydrologic, hydraulic and vegetation parameters. We apply the model to an exemplifying case, by investigating the vegetation response to a set of changes in mean discharge and coefficient of variation. The range of these changes is deduced from the analysis of field data in pre- and post-dam conditions. Firstly, we analyze the narrowing/widening process. In particular, we analyze two percentage differences of the starting transversal position with respect to

  5. Influence of flood variation on seasonal floodplain vegetation ...

    African Journals Online (AJOL)

    This study investigated the influence of flooding variation on floodplain vegetation in the Nxaraga Lagoon seasonal floodplains by sampling community composition and soil nutrient content in 1997, when flood levels were unusually low, and again in 2010 when flood levels were unusually high. In each of the eight ...

  6. Spatial variation in atmospheric nitrogen deposition on low canopy vegetation

    International Nuclear Information System (INIS)

    Verhagen, Rene; Diggelen, Rudy van

    2006-01-01

    Current knowledge about the spatial variation of atmospheric nitrogen deposition on a local scale is limited, especially for vegetation with a low canopy. We measured nitrogen deposition on artificial vegetation at variable distances of local nitrogen emitting sources in three nature reserves in the Netherlands, differing in the intensity of agricultural practices in the surroundings. In the nature reserve located in the most intensive agricultural region nitrogen deposition decreased with increasing distance to the local farms, until at a distance of 1500 m from the local nitrogen emitting sources the background level of 15 kg N ha -1 yr -1 was reached. No such trend was observed in the other two reserves. Interception was considerably lower than in woodlands and hence affected areas were larger. The results are discussed in relation to the prospects for the conservation or restoration of endangered vegetation types of nutrient-poor soil conditions. - Areas with low canopy vegetation are affected over much larger distances by nitrogen deposition than woodlands

  7. Influence of antioxidant rich fresh vegetable juices on starch induced postprandial hyperglycemia in rats.

    Science.gov (United States)

    Tiwari, Ashok K; Reddy, K Srikanth; Radhakrishnan, Janani; Kumar, D Anand; Zehra, Amtul; Agawane, Sachin B; Madhusudana, K

    2011-09-01

    This research analyzed the major chemical components and multiple antioxidant activities present in the fresh juice of eight vegetables, and studied their influence on starch induced postprandial glycemia in rats. A SDS-PAGE based protein fingerprint of each vegetable juice was also prepared. The yields of juice, chemical components like total proteins, total polyphenols, total flavonoids, total anthocyanins and free radicals like the ABTS˙(+) cation, DPPH, H(2)O(2), scavenging activities and reducing properties for NBT and FeCl(3) showed wide variations. Vegetable juice from brinjal ranked first in displaying total antioxidant capacity. Pretreatment of rats with vegetable juices moderated starch induced postprandial glycemia. The fresh juice from the vegetables ridge gourd, bottle gourd, ash gourd and chayote significantly mitigated postprandial hyperglycemic excursion. Total polyphenol concentrations present in vegetable juices positively influenced ABTS˙(+) scavenging activity and total antioxidant capacity. However, NBT reducing activity of juices was positively affected by total protein concentration. Contrarily, however, high polyphenol content in vegetable juice was observed to adversely affect the postprandial antihyperglycemic activity of vegetable juices. This is the first report exploring antihyperglycemic activity in these vegetable juices and highlights the possible adverse influence of high polyphenol content on the antihyperglycemic activity of the vegetable juices. This journal is © The Royal Society of Chemistry 2011

  8. Detection of vegetation stress from laser-induced fluorescence signatures

    International Nuclear Information System (INIS)

    Subhash, N.

    1995-01-01

    The in vivo laser-induced fluorescence (LIF) signatures of UV irradiated Salvia splendens plants were measured using an Optical Multichannel Analyser (OMA) system with Nitrogen laser excitation. The LIF spectra which consisted of the blue-green and the red chlorophyll bands were analysed with a non-linear interactive procedure using Gaussian spectral functions. The fluorescence intensity ratios of the various bands obtained from curve fitted parameters were found to be more sensitive to changes in the photosynthetic activity of the plant. The variation in the intensity ratio for the chlorophyll bands for nutrient stressed sunflower, cotton and groundnut plants as well as the nutrient and water stressed rice plants are also presented. It is observed that vegetation stress not only changes the fluorescence intensity ratios and the vitality index of the plant but also changes the peak position of the emission bands, in some cases. It is also seen that analysis of the fluorescence spectra in vegetation remote sensing applications would require a deconvolution procedure to evaluate the exact contribution of each band in the total spectra. (author). 23 refs, 8 figs, 5 tabs

  9. Climate contributions to vegetation variations in Central Asian drylands

    DEFF Research Database (Denmark)

    Zhou, Yu; Zhang, Li; Fensholt, Rasmus

    2015-01-01

    Central Asia comprises a large fraction of the world's drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index...

  10. Normalized difference vegetation index (NDVI) variation among cultivars and environments

    Science.gov (United States)

    Although Nitrogen (N) is an essential nutrient for crop production, large preplant applications of fertilizer N can result in off-field loss that causes environmental concerns. Canopy reflectance is being investigated for use in variable rate (VR) N management. Normalized difference vegetation index...

  11. Biovar Differentiation and Variation in Virulence of Ralstonia solanacearum Isolates Infecting Solanaceous Vegetables

    Directory of Open Access Journals (Sweden)

    Ram Devi Timila

    2016-12-01

    Full Text Available Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of solanaceous vegetables specially tomato (Lycopersicon esculentum L. and eggplant (Solanum melongena L.. Experiments were conducted to determine biovar types existing among the strains or isolates of Nepal and variation in virulence in some vegetables belonging to solanaceae family. A total of 39 isolates infecting tomato, eggplant, chilli and potato collected from different parts of Nepal were analyzed for biovar types on the basis of 3 disaccharides and 3 hexose alcohols oxidation test. Experiments were conducted to determine variation in virulence or aggressiveness of some of the isolates under screen house conditions using three host differentials such as Pusa Ruby (susceptible, Bishesh (moderately resistant and Srijana (resistant tomato cultivars. Of the 39 isolates, 23 were biovar III, three biovar II, three biovar IV, and one was biovar I. Nine isolates could not be differentiated into any of the five biovars. For breeding and epidemiological purposes it is very important to analyze the variability of aggressiveness. A total of 5 isolates collected from different places were included in the test. Isolates from Bhaktapur was found the most virulent causing wilt in the variety Bishesh (moderately resistant. Other isolates had the negative impact with zero wilt on the differentials used. Isolates from Jungekhola of Dhading district did not induce wilt even on susceptible variety (Pusa Ruby, but exhibited only senescence reaction. The result indicated that there is some slight variation among the isolates tested. Some effective management tactics might be needed in those locations where highly aggressive or virulent strain of bacterial wilt is prevalent, because resistant variety may not be stable in such locations.

  12. NDVI-Based analysis on the influence of human activities on vegetation variation on Hainan Island

    Science.gov (United States)

    Luo, Hongxia; Dai, Shengpei; Xie, Zhenghui; Fang, Jihua

    2018-02-01

    Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index (NDVI) dataset, we analyzed the predicted NDVI values variation and the influence of human activities on vegetation on Hainan Island during 2001-2015. We investigated the roles of human activities in vegetation variation, particularly from 2002 when implemented the Grain-for-Greenprogram on Hainan Island. The trend analysis, linear regression model and residual analysis were used to analyze the data. The results of the study showed that (1) The predicted vegetation on Hainan Island showed an general upward trend with a linear growth rate of 0.0025/10y (phuman activities. (3) In general, human activities had played a positive role in the vegetation increase on Hainan Island, and the residual NDVI trend of this region showed positive outcomes for vegetation variation after implementing ecological engineering projects. However, it indicated a growing risk of vegetation degradation in the coastal region of Hainan Island as a result of rapid urbanization, land reclamation.

  13. Genetic variation in the hTAS2R38 taste receptor and brassica vegetable intake

    DEFF Research Database (Denmark)

    Gorovic, Nela; Afzal, Shoaib; Tjonneland, Anne

    2011-01-01

    The human TAS2R38 receptor is believed to be partly responsible for the ability to taste phenylthiocarbamide (PTC), a bitter compound very similar to the bitter glucosinolates found in brassica vegetables. These vegetables and their active compounds have chemo-protective properties. This study...... investigated the relationship between genetic variation in the hTAS2R38 receptor and the actual consumption of brassica vegetables with the hypothesis that taster status was associated with intake of these vegetables. Furthermore, secondary intake information on alcohol, chocolate, coffee, smoking, BMI...... on their brassica vegetables intake from the upper quartile (>= a parts per thousand yen23 g/day) and the lower quartile (brassicas from a randomly selected sub-cohort of DCH. DNA was analysed for three functional SNPs in the hTAS2R38 gene. The hTAS2R38...

  14. [Spatiotemporal variation of vegetation in northern Shaanxi of Northwest China based on SPOT-VGT NDVI].

    Science.gov (United States)

    Yang, Yan-Zheng; Zhao, Peng-Xiang; Hao, Hong-Ke; Chang, Ming

    2012-07-01

    By using 1998-2010 SPOT-VGT NDVI images, this paper analyzed the spatiotemporal variation of vegetation in northern Shaanxi. In 1998-2010, the NDVI in northern Shaanxi had an obvious seasonal variation. The average monthly NDVI was the minimum (0.14) in January and the maximum (0.46) in August, with a mean value of 0.28. The average annual NDVI presented an overall increasing trend, indicating that the vegetation in this area was in restoring. Spatially, the restoration of vegetation in this area was concentrated in central south part, and the degradation mainly occurred in the north of the Great Wall. Air temperature and precipitation were the important climate factors affecting the variation of vegetation, with the linear correlation coefficients to NDVI being 0.72 and 0.58, respectively. The regions with better restored vegetation were mainly on the slopes of 15 degrees-25 degrees, indicating that the Program of Conversion of Cropland to Forestland and Grassland had a favorable effect in the vegetation restoration in northern Shaanxi.

  15. Observations of vegetation induced breezes and their impact on convection

    Science.gov (United States)

    Garcia-Carreras, Luis; Parker, Douglas J.; Taylor, Christopher M.; Reeves, Claire; Murphy, Jennifer

    2010-05-01

    Aircraft observations over Benin during the early afternoon of 17 August 2006 are used to look at the impact of heterogeneities in vegetation cover, primarily between crop and forest/shrub, on the thermodynamic and dynamical properties of the planetary boundary layer (PBL). Isoprene, a biogenic organic compound emitted primarily by woody vegetation species, was measured and is used to link the vegetation patterns to the PBL properties. The aircraft observations show the presence of a persistent mesoscale organization of the winds persisting over two hours, controlling the pattern of cumulus congestus cloud in the area. The mesoscale flows are closely linked to temperature anomalies that mirror the vegetation patterns at the surface. These results are consistent with the presence of higher Bowen ratios over forested areas, associated with higher evapotranspiration and isoprene emissions, producing negative PBL temperature anomalies over the forested area compared to adjacent cropland. The temperature gradients that thus arise at vegetation boundaries are then sufficient to initiate vegetation breezes. The relationships between PBL temperatures and isoprene, linking the land-surface to the PBL, and PBL temperatures and winds are very significant for length-scales above 10 and 8km respectively. The convergence zones, and therefore clouds, associated with the land-induced mesoscale flows tend to occur on the southern edge of the warm temperature anomalies. This is attributed to the presence of a northerly synoptic flow, which strengthens the southerly parts of the mesoscale flow, as well as displacing the convergence zones southward. A visible satellite climatology for the whole season shows an enhancement of cloud over the cropland during the early afternoon, consistent with the presence of land-induced flows. These results suggest that the presence of these flows have a climatological impact on the initiation of convection in the region.

  16. Topography induced spatial variations in diurnal cycles of assimilation and latent heat of Mediterranean forest

    Science.gov (United States)

    van der Tol, C.; Dolman, A. J.; Waterloo, M. J.; Raspor, K.

    2007-02-01

    The aim of this study is to explain topography induced spatial variations in the diurnal cycles of assimilation and latent heat of Mediterranean forest. Spatial variations of the fluxes are caused by variations in weather conditions and in vegetation characteristics. Weather conditions reflect short-term effects of climate, whereas vegetation characteristics, through adaptation and acclimation, long-term effects of climate. In this study measurements of plant physiology and weather conditions are used to explain observed differences in the fluxes. A model is used to study which part of the differences in the fluxes is caused by weather conditions and which part by vegetation characteristics. Data were collected at four experimental sub-Mediterranean deciduous forest plots in a heterogeneous terrain with contrasting aspect, soil water availability, humidity and temperature. We used a sun-shade model to scale fluxes from leaf to canopy, and calculated the canopy energy balance. Parameter values were derived from measurements of light interception, leaf chamber photosynthesis, leaf nitrogen content and 13C isotope discrimination in leaf material. Leaf nitrogen content is a measure of photosynthetic capacity, and 13C isotope discrimination of water use efficiency. For validation, sap-flux based measurements of transpiration were used. The model predicted diurnal cycles of transpiration and stomatal conductance, both their magnitudes and differences in afternoon stomatal closure between slopes of different aspect within the confidence interval of the validation data. Weather conditions mainly responsible for the shape of the diurnal cycles, and vegetation parameters for the magnitude of the fluxes. Although the data do not allow for a quantification of the two effects, the differences in vegetation parameters and weather among the plots and the sensitivity of the fluxes to them suggest that the diurnal cycles were more strongly affected by spatial variations in

  17. Topography induced spatial variations in diurnal cycles of assimilation and latent heat of Mediterranean forest

    Directory of Open Access Journals (Sweden)

    C. van der Tol

    2007-01-01

    Full Text Available The aim of this study is to explain topography induced spatial variations in the diurnal cycles of assimilation and latent heat of Mediterranean forest. Spatial variations of the fluxes are caused by variations in weather conditions and in vegetation characteristics. Weather conditions reflect short-term effects of climate, whereas vegetation characteristics, through adaptation and acclimation, long-term effects of climate. In this study measurements of plant physiology and weather conditions are used to explain observed differences in the fluxes. A model is used to study which part of the differences in the fluxes is caused by weather conditions and which part by vegetation characteristics. Data were collected at four experimental sub-Mediterranean deciduous forest plots in a heterogeneous terrain with contrasting aspect, soil water availability, humidity and temperature. We used a sun-shade model to scale fluxes from leaf to canopy, and calculated the canopy energy balance. Parameter values were derived from measurements of light interception, leaf chamber photosynthesis, leaf nitrogen content and 13C isotope discrimination in leaf material. Leaf nitrogen content is a measure of photosynthetic capacity, and 13C isotope discrimination of water use efficiency. For validation, sap-flux based measurements of transpiration were used. The model predicted diurnal cycles of transpiration and stomatal conductance, both their magnitudes and differences in afternoon stomatal closure between slopes of different aspect within the confidence interval of the validation data. Weather conditions mainly responsible for the shape of the diurnal cycles, and vegetation parameters for the magnitude of the fluxes. Although the data do not allow for a quantification of the two effects, the differences in vegetation parameters and weather among the plots and the sensitivity of the fluxes to them suggest that the diurnal cycles were more strongly affected by spatial

  18. Vegetation dynamics induced by phreatophyte--aquifer interactions.

    Science.gov (United States)

    Ridolfi, Luca; D'Odorico, Paolo; Laio, Francesco

    2007-09-21

    The dynamics of phreatophyte vegetation are strongly coupled to those of the shallow phreatic aquifers from which phreatophytes extract water. Vegetation is able to influence the depth of the water table, which, in turn, can induce stress in vegetation. These interactions are likely to affect the composition and structure of phreatophyte plant communities, as well as their successional dynamics. Despite the environmental and economical value of many wetland plant ecosystems around the world, the impact of vegetation-water table interactions on ecosystem succession and interspecies competition in phreatophyte plant communities remains poorly understood. This study develops a minimalistic modelling framework to investigate the dynamics of two phreatophyte species, and their interactions with the water table. In spite of its simplicity, the model exhibits a remarkable variety of dynamical behaviors, especially when the water table depth is forced by external drivers. It is shown that, even when one of the two species is dominant with respect to the other, these two species can coexist showing periodic, quasi-periodic, and chaotic dynamics. Moreover, in the presence of a random environmental forcing, noise-induced coexistence may emerge.

  19. Spatio-temporal variations of vegetation indicators in Eastern Siberia under global warming

    Science.gov (United States)

    Varlamova, Eugenia V.; Solovyev, Vladimir S.

    2017-11-01

    Study of spatio-temporal variations of NDVI (Normalized Difference Vegetation Index) and phenological parameters of Eastern Siberia vegetation cover under global warming was carried out on AVHRR/NOAA data (1982-2014). Trend maps of NDVI and annual variations of phenological parameters and NDVI are analyzed. A method based on stable transition of air temperature through +5°C was used to estimate the beginning, end and the length of the growing season. Correlation between NDVI and phenological parameters, surface air temperature and precipitation are discussed.

  20. Analysis of the Driving Forces in Vegetation Variation in the Grain for Green Program Region, China

    Directory of Open Access Journals (Sweden)

    Wang Hao

    2017-10-01

    Full Text Available The Chinese government introduced six ecological restoration programs to improve its natural environment. Although these programs have proven successful in improving local environmental conditions, some studies have questioned their effectiveness when regions suffer from extreme weather conditions. Using the Grain for Green Program (GGP region as a study area, we estimated vegetation activities in the GGP region from 2000 to 2010 to clarify the trends in vegetation growth and their driving forces. The results showed that: (1 vegetation activities improved in the GGP region during 2000-2010, with 58.94% of the area showing an increased trend in the NDVI (normalized difference vegetation index; (2 26.33% of the increased vegetation was caused by human interference, and 11.61% by climate variation, human activity was the dominant cause, and resulted in 54.68% of the degradation compared to 4.74% from climate change; and, (3 the contribution of different land use types to the NDVI interannual variations showed that high contribution regions were focused in the arid and semiarid areas, where the vegetation growth is associated with variations in recipitation and temperature. However, conversions between farmland and grassland or forest had a significant effect on the change in the NDVI trend. Therefore, although climate conditions can affect vegetation growth, human activities are more important in vegetation changes, and appropriate human activities would contribute to its continual improvement. Hence, we recommend establishing an assessment and scientific management mechanism for eco-risks in the design and management of ecosystem restoration programs.

  1. Light-induced vegetative anthocyanin pigmentation in Petunia

    OpenAIRE

    Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

    2009-01-01

    The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins...

  2. [Responses of vegetation changes to climatic variations in Panxi area based on the MODIS multispectral data].

    Science.gov (United States)

    Shao, Huai-Yong; Wu, Jin-Hui; Liu, Meng; Yang, Wu-Nian

    2014-01-01

    It is an important research area to quantitatively studying the relationship between global climatic change and vegetation change based on the remote sensing technology. Panxi area is the ecological barrier of the upper reaches of the Yangtze River, and it is essential for the stability of the ecological environment of Sichuan as well as that of the whole China. The present article analyzes the vegetation change in 2001-2008 and the relationship between vegetation change and climatic variations of Panxi area, based on MODIS multispectral data and meteorological data. The results indicate that NDVI is positively correlated with temperature and precipitation. The precipitation is the major factor that affects the change of vegetation in the Panxi region and the trend of NDVI is similar with autumn precipitation; while at the same time the influence of climate has a one-month-time-lag.

  3. The Relationship of Temporal Variations in SMAP Vegetation Optical Depth to Plant Hydraulic Behavior

    Science.gov (United States)

    Konings, A. G.

    2016-12-01

    The soil emissions measured by L-band radiometers such as that on the NASA Soil Moisture Active/Passive mission are modulated by vegetation cover as quantified by the soil scattering albedo and the vegetation optical depth (VOD). The VOD is linearly proportional to the total vegetation water content, which is dependent on both the biomass and relative water content of the plant. Biomass is expected to vary more slowly than water content. Variations in vegetation water content are highly informative as they are directly indicative of the degree of hydraulic stress (or lack thereof) experienced by the plant. However, robust retrievals are needed in order for SMAP VOD observations to be useful. This is complicated by the fact that multiple unknowns (soil moisture, VOD, and albedo) need to be determined from two highly correlated polarizations. This presentation will discuss the application to SMAP of a recently developed timeseries algorithm for VOD and albedo retrieval - the Multi-Temporal Dual Channel Algorithm MTDCA, and its interpretation for plant hydraulic applications. The MT-DCA is based on the assumption that, for consecutive overpasses at a given time of day, VOD varies more slowly than soil moisture. A two-overpass moving average can then be used to determine variations in VOD that are less sensitive to high-frequency noise than classical dual-channel algorithms. Seasonal variations of SMAP VOD are presented and compared to expected patterns based on rainfall and radiation seasonality. Taking advantage of the large diurnal variation (relative to the seasonal variation) of canopy water potention, diurnal variations (between 6AM and 6PM observations) of SMAP VOD are then used to calculate global variations in ecosystem-scale isohydricity - the degree of stomatal closure and xylem conductivity loss in response to water stress. Lastly, the effect of satellite sensing frequency and overpass time on water content across canopies of different height will be

  4. Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

    International Nuclear Information System (INIS)

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.

    1999-01-01

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist

  5. Environmental variation, vegetation distribution, carbon dynamics and water/energy exchange at high latitudes

    Science.gov (United States)

    McGuire, A.D.; Wirth, C.; Apps, M.; Beringer, J.; Clein, J.; Epstein, H.; Kicklighter, D.W.; Bhatti, J.; Chapin, F. S.; De Groot, B.; Efremov, D.; Eugster, W.; Fukuda, M.; Gower, T.; Hinzman, L.; Huntley, B.; Jia, G.J.; Kasischke, E.; Melillo, J.; Romanovsky, V.; Shvidenko, A.; Vaganov, E.; Walker, D.

    2002-01-01

    The responses of high latitude ecosystems to global change involve complex interactions among environmental variables, vegetation distribution, carbon dynamics, and water and energy exchange. These responses may have important consequences for the earth system. In this study, we evaluated how vegetation distribution, carbon stocks and turnover, and water and energy exchange are related to environmental variation spanned by the network of the IGBP high latitude transects. While the most notable feature of the high latitude transects is that they generally span temperature gradients from southern to northern latitudes, there are substantial differences in temperature among the transects. Also, along each transect temperature co-varies with precipitation and photosynthetically active radiation, which are also variable among the transects. Both climate and disturbance interact to influence latitudinal patterns of vegetation and soil carbon storage among the transects, and vegetation distribution appears to interact with climate to determine exchanges of heat and moisture in high latitudes. Despite limitations imposed by the data we assembled, the analyses in this study have taken an important step toward clarifying the complexity of interactions among environmental variables, vegetation distribution, carbon stocks and turnover, and water and energy exchange in high latitude regions. This study reveals the need to conduct coordinated global change studies in high latitudes to further elucidate how interactions among climate, disturbance, and vegetation distribution influence carbon dynamics and water and energy exchange in high latitudes.

  6. UV-induced carbon monoxide emission from living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard

    2013-01-01

    The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop...... to either an ecosystem chamber or a plant-leaf scale chamber. Leaves of all examined plant species exhibited emission of CO in response to artificial UV-radiation as well as the UV-component of natural solar radiation. The UV-induced rate of CO emission exhibited a rather low dependence on temperature......, indicating an abiotic process. The emission of CO in response to the UV-component of natural solar radiation was also evident at the ecosystem scale....

  7. Variation of MODIS reflectance and vegetation indices with viewing geometry and soybean development.

    Science.gov (United States)

    Breunig, Fábio M; Galvão, Lênio S; Formaggio, Antônio R; Epiphanio, José C N

    2012-06-01

    Directional effects introduce a variability in reflectance and vegetation index determination, especially when large field-of-view sensors are used (e.g., Moderate Resolution Imaging Spectroradiometer - MODIS). In this study, we evaluated directional effects on MODIS reflectance and four vegetation indices (Normalized Difference Vegetation Index - NDVI; Enhanced Vegetation Index - EVI; Normalized Difference Water Index - NDWI(1640) and NDWI(2120)) with the soybean development in two growing seasons (2004-2005 and 2005-2006). To keep the reproductive stage for a given cultivar as a constant factor while varying viewing geometry, pairs of images obtained in close dates and opposite view angles were analyzed. By using a non-parametric statistics with bootstrapping and by normalizing these indices for angular differences among viewing directions, their sensitivities to directional effects were studied. Results showed that the variation in MODIS reflectance between consecutive phenological stages was generally smaller than that resultant from viewing geometry for closed canopies. The contrary was observed for incomplete canopies. The reflectance of the first seven MODIS bands was higher in the backscattering. Except for the EVI, the other vegetation indices had larger values in the forward scattering direction. Directional effects decreased with canopy closure. The NDVI was lesser affected by directional effects than the other indices, presenting the smallest differences between viewing directions for fixed phenological stages.

  8. Spatial Variation of Temperature and Precipitation in Bhutan and Links to Vegetation and Land Coveropen access

    DEFF Research Database (Denmark)

    Dorji, Ugyen; Olesen, Jørgen Eivind; Bøcher, Peder Klith

    2016-01-01

    Bhutan, located in the Himalayas in the South Asian monsoon region, has extremely high variation in elevation, climatic conditions, and land cover despite its small geographical area, as well as great biodiversity. This paper provides the first comprehensive description of climatic conditions....... The spatial distribution of precipitation was mainly controlled by latitude, having a quadratic relationship, with the highest rates in the southern foothills of the Himalayan range and the lowest at midlatitudes. The land cover is affected by topography and local climate, with variations in temperature being...... a main deciding factor for vegetation types; most human settlements and associated land uses are concentrated at lower elevations....

  9. Remote sensing vegetation status by laser-induced fluorescence

    International Nuclear Information System (INIS)

    Günther, K.P.; Dahn, H.G.; Lüdeker, W.

    1994-01-01

    In November 1989 the EUREKA project LASFLEUR (EU 380) started as an European research effort to investigate the future application of far-field laser-induced plant fluorescence for synoptic, airborne environmental monitoring of vegetation. This report includes a brief introduction in a theoretically approach for the laser-induced fluorescence signals of leaves and their spectral and radiometric behaviour. In addition, a detailed description of the design and realization of the second generation of the far-field fluorescence lidar (DLidaR-2) is given with special regard to the optical and electronical setup, followed by a short explanation of the data processing. The main objectives of the far field measurements are to demonstrate the link between laser-induced fluorescence data and plant physiology and to show the reliability of remote single shot lidar measurements. The data sets include the typical daily cycles of the fluorescence for different global irradiation. As expected from biophysical models, the remotely sensed chlorophyll fluorescence is highly correlated with the carbon fixation rate, while the fluorescence ratio F685 / F730 is only dependent on the chlorophyll concentration. Drought stress measurement of evergreen oaks Quercus pubescens confirm the findings of healthy plants with regard to the fluorescence ratio F685 / F730 while the fluorescence signals of stressed plants show a different behavior than nonstressed plants. Additionally, the corresponding physiological data (porometer and PAM data) are presented. (author)

  10. Light-induced vegetative anthocyanin pigmentation in Petunia

    Science.gov (United States)

    Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

    2009-01-01

    The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillaris×(Petunia axillaris×Petunia hybrida cv. ‘Rose of Heaven’)]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (Amax). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors. PMID:19380423

  11. A vegetation control on seasonal variations in global atmospheric mercury concentrations

    Science.gov (United States)

    Jiskra, Martin; Sonke, Jeroen E.; Obrist, Daniel; Bieser, Johannes; Ebinghaus, Ralf; Myhre, Cathrine Lund; Pfaffhuber, Katrine Aspmo; Wängberg, Ingvar; Kyllönen, Katriina; Worthy, Doug; Martin, Lynwill G.; Labuschagne, Casper; Mkololo, Thumeka; Ramonet, Michel; Magand, Olivier; Dommergue, Aurélien

    2018-04-01

    Anthropogenic mercury emissions are transported through the atmosphere as gaseous elemental mercury (Hg(0)) before they are deposited to Earth's surface. Strong seasonality in atmospheric Hg(0) concentrations in the Northern Hemisphere has been explained by two factors: anthropogenic Hg(0) emissions are thought to peak in winter due to higher energy consumption, and atmospheric oxidation rates of Hg(0) are faster in summer. Oxidation-driven Hg(0) seasonality should be equally pronounced in the Southern Hemisphere, which is inconsistent with observations of constant year-round Hg(0) levels. Here, we assess the role of Hg(0) uptake by vegetation as an alternative mechanism for driving Hg(0) seasonality. We find that at terrestrial sites in the Northern Hemisphere, Hg(0) co-varies with CO2, which is known to exhibit a minimum in summer when CO2 is assimilated by vegetation. The amplitude of seasonal oscillations in the atmospheric Hg(0) concentration increases with latitude and is larger at inland terrestrial sites than coastal sites. Using satellite data, we find that the photosynthetic activity of vegetation correlates with Hg(0) levels at individual sites and across continents. We suggest that terrestrial vegetation acts as a global Hg(0) pump, which can contribute to seasonal variations of atmospheric Hg(0), and that decreasing Hg(0) levels in the Northern Hemisphere over the past 20 years can be partly attributed to increased terrestrial net primary production.

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

    Science.gov (United States)

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

    2011-04-01

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

  13. Induced mutations in highly heterozygous vegetatively propagated grasses

    International Nuclear Information System (INIS)

    Powell, J.B.

    1976-01-01

    Experience with mutation induction of turf and forage grasses indicates that much progress can be achieved by this method. More than 300 mutations have been produced in our laboratory in the cultivars Tifgreen and Tifdwarf bermudagrass (Cynodon sp.). In the Tifway and Tifcote bermudagrasses we have demonstrated similar mutation responses. The first three clones are triploids and Tifcote is a probable tetraploid. No seeds are set on these clones. Two clones of bermudagrass, Coastal and Coastcross-1, occupy millions of hectares in the USA. Both are mutable and are known to be hybrids with 36 chromosomes. Biotypes of dallisgrass (Paspalum dilatatum Poir.) exist with 40 and 50 chromosomes and reproduce as sexual and obligate apomictic forms. Gamma-ray and thermal-neutron treatment of seed of these biotypes produced mutants that maintained the maternal characteristics in subsequent generations. Bahiagrass (Paspalum notatum Fluegge) also has sexual and apomictic biotypes. Some success was indicated for increased seed set by mutagen treatment. Kentucky bluegrass (Poa pratensis L.) is a facultative apomict with varying numbers of chromosomes in different cultivars. Gamma-ray mutagen treatment of rhizomes produced numerous mutations for plant type and disease reaction. Most mutations perpetuate themselves through the seed. The characteristic in common with all these grasses is their heterozygosity, which is maintained by the vegetative propagation or apomictic mode of reproduction. The experience in using ionizing radiation to induce heritable changes in these vegetatively propagated grasses is one of considerable success. Mutation rates in some of these irradiated grasses exceeded 65% and aberrant plants with characteristics previously never observed were found. Numerous hemizygous and heterozygous loci seem to be a sensitive target for mutagens. (author)

  14. Assessing vegetation response to climatic variations and human activities: spatiotemporal NDVI variations in the Hexi Corridor and surrounding areas from 2000 to 2010

    Science.gov (United States)

    Guan, Qingyu; Yang, Liqin; Guan, Wenqian; Wang, Feifei; Liu, Zeyu; Xu, Chuanqi

    2018-03-01

    Vegetation cover is a commonly used indicator for evaluating terrestrial environmental conditions, and for revealing environmental evolution and transitions. Spatiotemporal variations in the vegetation cover of the Hexi Corridor and surrounding areas from 2000 to 2010 were investigated using MODIS NDVI data, and the causes of vegetation cover changes were analyzed, considering both climatic variability and human activities. The vegetation cover of the study area increased during 2000-2010. The greenness of the vegetation showed a significant increase from the northwest to the southeast, which was similar to the spatial distribution of the annual precipitation. Variations in vegetation have a close relationship with those in precipitation within the Qilian Mountains region, but the NDVI is negatively correlated with precipitation in oasis areas. Increasing temperatures led to drought, inhibiting vegetation growth in summer; however, increasing temperatures may have also advanced and prolonged the growing periods in spring and autumn. The NDVI showed a slight degradation in March and July, primarily in the Qilian Mountains, and especially the Wushao Mountains. In March, due to low temperatures, the metabolism rate of vegetation was too slow to enable strong plant growth in high elevations of the Qilian Mountains. In July, increasing temperatures enhanced the intensity of transpiration and decreasing precipitation reduced the moisture available to plants, producing a slight degradation of vegetation in the Qilian Mountains. In May and August, the NDVI showed a significant improvement, primarily in the artificial oases and the Qilian Mountains. Abundant precipitation provided the necessary water for plant growth, and suitable temperatures increased the efficiency of photosynthesis, resulting in a significant improvement of vegetation in the Qilian Mountains. The improvement of production technologies, especially in irrigation, has been beneficial to the growth of

  15. Spatial Variation of Temperature and Precipitation in Bhutan and Links to Vegetation and Land Cover

    Directory of Open Access Journals (Sweden)

    Ugyen Dorji

    2016-02-01

    Full Text Available Bhutan, located in the Himalayas in the South Asian monsoon region, has extremely high variation in elevation, climatic conditions, and land cover despite its small geographical area, as well as great biodiversity. This paper provides the first comprehensive description of climatic conditions in Bhutan. It assesses the spatial variation of temperature and precipitation across the country and evaluates the causes for this variation based on daily data from 70 meteorological stations that have been recording data for time spans ranging from 3 to 21 years. Temperature and precipitation show contrasting spatial variation, with temperature primarily affected by elevation and precipitation by latitude. Models were developed using mixed linear regression models to predict seasonal and annual mean temperature and precipitation based on geographical location. Using linear regression we found that temperatures changed by about 0.5°C for every 100 m of change in elevation, with lapse rates being highest in February, March, and November and lowest from June to August. The lapse rate was highest for minimum temperatures and lowest for maximum temperatures, with the greatest difference during winter. The spatial distribution of precipitation was mainly controlled by latitude, having a quadratic relationship, with the highest rates in the southern foothills of the Himalayan range and the lowest at midlatitudes. The land cover is affected by topography and local climate, with variations in temperature being a main deciding factor for vegetation types; most human settlements and associated land uses are concentrated at lower elevations.

  16. Variation of strontium stable isotope ratios and origins of strontium in Japanese vegetables and comparison with Chinese vegetables.

    Science.gov (United States)

    Aoyama, Keisuke; Nakano, Takanori; Shin, Ki-Cheol; Izawa, Atsunobu; Morita, Sakie

    2017-12-15

    To evaluate the utility of 87 Sr/ 86 Sr ratio for determining the geographical provenance of vegetables, we compared 87 Sr/ 86 Sr ratios and Sr concentrations in five vegetable species grown in Japan and China, and we also examined the relationships between 87 Sr/ 86 Sr ratios in vegetables, the soil-exchangeable pool, irrigation water, and fertilizer from 20 Japanese agricultural areas. The vegetable 87 Sr/ 86 Sr ratios in Japan were similar for all species within a given agricultural area, but tended to be low in northeast Japan and high in southwest Japan. The median 87 Sr/ 86 Sr ratio in Japanese vegetables was similar to that in fertilizer, suggesting that in addition to rock-derived Sr, vegetables contain Sr derived from fertilizers. In most cases, the 87 Sr/ 86 Sr ratios for the Japanese and Chinese vegetables differed by approximately 0.710. Linear discriminant analysis using both 87 Sr/ 86 Sr and the Sr concentration allowed more accurate discrimination between vegetables from the two countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Variation trends of the vegetations in distribution region of Amur tiger based on MODIS NDVI].

    Science.gov (United States)

    Wang, Hua-Ru; Wang, Tian-Ming; Ge, Han-Ping

    2012-10-01

    By using the averaged 250 m MODIS NDVI data in growth seasons of 2000-2010 and the approach of ordinary linear regression, this paper analyzed the variation trends of the vegetations in the distribution region of Amur tiger (Panthera tigris altaica), the Far East region of Russia and the eastern part of Northeast China, as well as the relationships between these variation trends and the anthropogenic activities. In 2000 - 2010, the areas with significantly decreased NDVI were sparsely distributed and accounted for 9.6% of the total, while the areas with significantly increased NDVI were mainly concentrated in the central part of northern Russia Far East Region and only accounted for 0.5% of the total. The percentage of the areas with significantly decreased NDVI in the distribution region of Amur tiger was slightly higher than that in the whole study region. The areas with significantly decreased NDVI were mainly distributed in the places of low elevation, gentle slope, and close to roads/railroads. The number of the pixels with significantly decreased NDVI increased with the increase of the nearest distance to residential locations first, and then decreased gradually. The significant decrease of the NDVI was closely related to the anthropogenic activities, and thus, to adopt effective measures to reduce human disturbances could control the vegetation degradation, and further, provide sustainable basis for the protection of Amur tiger and the conservation of the biodiversity in the studied region.

  18. Dealing with Variations over Space and Time in Urban Vegetation-Air Quality Assessment

    Science.gov (United States)

    Tan, P. Y.

    2017-12-01

    multiple scales and temporal variations in air quality. They present challenges in field studies seeking to establish causality between urban vegetation, air quality improvement and public health status. Suggestions on approaches and additional questions that need to be asked will be shared during the panel discussion.

  19. Vegetation

    DEFF Research Database (Denmark)

    Epstein, H.E.; Walker, D.A.; Bhatt, U.S.

    2012-01-01

    increased 20-26%. • Increasing shrub growth and range extension throughout the Low Arctic are related to winter and early growing season temperature increases. Growth of other tundra plant types, including graminoids and forbs, is increasing, while growth of mosses and lichens is decreasing. • Increases...... in vegetation (including shrub tundra expansion) and thunderstorm activity, each a result of Arctic warming, have created conditions that favor a more active Arctic fire regime....

  20. Lateral variations in vegetation in the Himalaya since the Miocene and implications for climate evolution

    Science.gov (United States)

    Vögeli, Natalie; Najman, Yani; van der Beek, Peter; Huyghe, Pascale; Wynn, Peter M.; Govin, Gwladys; van der Veen, Iris; Sachse, Dirk

    2017-08-01

    The Himalaya has a major influence on global and regional climate, in particular on the Asian monsoon system. The foreland basin of the Himalaya contains a record of tectonics and paleoclimate since the Miocene. Previous work on the evolution of vegetation and climate has focused on the central and western Himalaya, where a shift from C3 to C4 vegetation has been observed at ∼7 Ma and linked to increased seasonality, but the climatic evolution of the eastern part of the orogen is less well understood. In order to track vegetation as a marker of monsoon intensity and seasonality, we analyzed δ13 C and δ18 O values of soil carbonate and associated δ13 C values of bulk organic carbon from previously dated sedimentary sections exposing the syn-orogenic detrital Dharamsala and Siwalik Groups in the west, and, for the first time, the Siwalik Group in the east of the Himalayan foreland basin. Sedimentary records span from 20 to 1 Myr in the west (Joginder Nagar, Jawalamukhi, and Haripur Kolar sections) and from 13 to 1 Myr in the east (Kameng section), respectively. The presence of soil carbonate in the west and its absence in the east is a first indication of long-term lateral climatic variation, as soil carbonate requires seasonally arid conditions to develop. δ13 C values in soil carbonate show a shift from around -10‰ to -2‰ at ∼7 Ma in the west, which is confirmed by δ13 C analyses on bulk organic carbon that show a shift from around -23‰ to -19‰ at the same time. Such a shift in isotopic values is likely to be associated with a change from C3 to C4 vegetation. In contrast, δ13 C values of bulk organic carbon remain at ∼ - 23 ‰ in the east. Thus, our data show that the current east-west variation in climate was established at 7 Ma. We propose that the regional change towards a more seasonal climate in the west is linked to a decrease of the influence of the Westerlies, delivering less winter precipitation to the western Himalaya, while the east

  1. Variation in Protein Intake Induces Variation in Spider Silk Expression

    Science.gov (United States)

    Blamires, Sean J.; Wu, Chun-Lin; Tso, I-Min

    2012-01-01

    Background It is energetically expensive to synthesize certain amino acids. The proteins (spidroins) of spider major ampullate (MA) silk, MaSp1 and MaSp2, differ in amino acid composition. Glutamine and proline are prevalent in MaSp2 and are expensive to synthesize. Since most orb web spiders express high proline silk they might preferentially attain the amino acids needed for silk from food and shift toward expressing more MaSp1 in their MA silk when starved. Methodology/Principal Findings We fed three spiders; Argiope aetherea, Cyrtophora moluccensis and Leucauge blanda, high protein, low protein or no protein solutions. A. aetherea and L. blanda MA silks are high in proline, while C. moluccesnsis MA silks are low in proline. After 10 days of feeding we determined the amino acid compositions and mechanical properties of each species' MA silk and compared them between species and treatments with pre-treatment samples, accounting for ancestry. We found that the proline and glutamine of A. aetherea and L. blanda silks were affected by protein intake; significantly decreasing under the low and no protein intake treatments. Glutmaine composition in C. moluccensis silk was likewise affected by protein intake. However, the composition of proline in their MA silk was not significantly affected by protein intake. Conclusions Our results suggest that protein limitation induces a shift toward different silk proteins with lower glutamine and/or proline content. Contradictions to the MaSp model lie in the findings that C. moluccensis MA silks did not experience a significant reduction in proline and A. aetherea did not experience a significant reduction in serine on low/no protein. The mechanical properties of the silks could not be explained by a MaSp1 expressional shift. Factors other than MaSp expression, such as the expression of spidroin-like orthologues, may impact on silk amino acid composition and spinning and glandular processes may impact mechanics. PMID:22363691

  2. Variation of MODIS reflectance and vegetation indices with viewing geometry and soybean development

    Directory of Open Access Journals (Sweden)

    Fábio M. Breunig

    2012-06-01

    Full Text Available Directional effects introduce a variability in reflectance and vegetation index determination, especially when large field-of-view sensors are used (e.g., Moderate Resolution Imaging Spectroradiometer - MODIS. In this study, we evaluated directional effects on MODIS reflectance and four vegetation indices (Normalized Difference Vegetation Index - NDVI; Enhanced Vegetation Index - EVI; Normalized Difference Water Index - NDWI1640 and NDWI2120 with the soybean development in two growing seasons (2004-2005 and 2005-2006. To keep the reproductive stage for a given cultivar as a constant factor while varying viewing geometry, pairs of images obtained in close dates and opposite view angles were analyzed. By using a non-parametric statistics with bootstrapping and by normalizing these indices for angular differences among viewing directions, their sensitivities to directional effects were studied. Results showed that the variation in MODIS reflectance between consecutive phenological stages was generally smaller than that resultant from viewing geometry for closed canopies. The contrary was observed for incomplete canopies. The reflectance of the first seven MODIS bands was higher in the backscattering. Except for the EVI, the other vegetation indices had larger values in the forward scattering direction. Directional effects decreased with canopy closure. The NDVI was lesser affected by directional effects than the other indices, presenting the smallest differences between viewing directions for fixed phenological stages.Efeitos direcionais introduzem variabilidade na reflectância e na determinação de índices de vegetação, especialmente quando sensores de amplo campo de visada são usados (p.ex., Moderate Resolution Imaging Spectroradiometer - MODIS. Neste estudo, nós avaliamos os efeitos direcionais sobre a reflectância e quatro índices de vegetação (Normalized Difference Vegetation Index - NDVI; Enhanced Vegetation Index - EVI; Normalized

  3. Assessment of Vegetation Variation on Primarily Creation Zones of the Dust Storms Around the Euphrates Using Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Jamil Amanollahi

    2012-06-01

    Full Text Available Recently, period frequency and effect domain of the dust storms that enter Iran from Iraq have increased. In this study, in addition to detecting the creation zones of the dust storms, the effect of vegetation cover variation on their creation was investigated using remote sensing. Moderate resolution image Spectroradiometer (MODIS and Landsat Thematic Mapper (TM5 have been utilized to identify the primarily creation zones of the dust storms and to assess the vegetation cover variation, respectively. Vegetation cover variation was studied using Normalized Differences Vegetation Index (NDVI obtained from band 3 and band 4 of the Landsate satellite. The results showed that the surrounding area of the Euphrates in Syria, the desert in the vicinity of this river in Iraq, including the deserts of Alanbar Province, and the north deserts of Saudi Arabia are the primarily creation zones of the dust storms entering west and south west of Iran. The results of NDVI showed that excluding the deserts in the border of Syria and Iraq, the area with very weak vegetation cover have increased between 2.44% and 20.65% from 1991 to 2009. In the meanwhile, the retention pound surface areas in the south deserts of Syria as well as the deserts in its border with Iraq have decreased 6320 and 4397 hectares, respectively. As it can be concluded from the findings, one of the main environmental parameters initiating these dust storms is the decrease in the vegetation cover in their primarily creation zones.

  4. Use of novel DNA fingerprinting techniques for the detection and characterization of genetic variation in vegetatively propagated crops. Proceedings of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    1998-10-01

    Vegetative propagated crops, such as banana and platain, sweet potato, yam, sugarcane and cassava, represent important sources of food in the developing countries. Although some of these crops may produce seeds, they must for practical purposes be propagated vegetatively. As normal plant breeding strategies based on genetic hybridization are of limited value or not applicable to such crops, it is necessary to assess the genetic diversity already existing in these crops and to design breeding strategies accordingly. If the existing genetic variation is shown to be too narrow for breeding purposes, one promising possibility for the introduction of genetic variability is the use of mutations induced by radiation or chemical mutagens. This CRP focused on: the detection of genetic diversity induced by mutagenic treatment or in vitro culture; the development of crop-specific markers; and increasing co-operation between molecular biologists in advanced laboratories and plant breeders and molecular biologists in the developing countries. The success of this CRP is evidenced by the introduction and application of new molecular methods by laboratories in developing countries, specially for the analysis of local crop genetic diversity. These exciting preliminary results show the potential for applications in crop improvement but much work remains to be done. Many of the vegetatively propagated species are ''orphan crops'', under-investigated on the international level. The development of new uses of transgenesis for the development of edible vaccines should not be overlooked. The challenge that remains is in the application of these new tools for practical end-user oriented improvements in vegetatively propagated crops. The present publication summarizes the third and final Research Co-ordination Meeting on the Use of Novel DNA Fingerprinting Techniques for the Detection and Characterization of Genetic Variation in Vegetatively Propagated Crops

  5. Use of novel DNA fingerprinting techniques for the detection and characterization of genetic variation in vegetatively propagated crops. Proceedings of a final research co-ordination meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    Vegetative propagated crops, such as banana and platain, sweet potato, yam, sugarcane and cassava, represent important sources of food in the developing countries. Although some of these crops may produce seeds, they must for practical purposes be propagated vegetatively. As normal plant breeding strategies based on genetic hybridization are of limited value or not applicable to such crops, it is necessary to assess the genetic diversity already existing in these crops and to design breeding strategies accordingly. If the existing genetic variation is shown to be too narrow for breeding purposes, one promising possibility for the introduction of genetic variability is the use of mutations induced by radiation or chemical mutagens. This CRP focused on: the detection of genetic diversity induced by mutagenic treatment or in vitro culture; the development of crop-specific markers; and increasing co-operation between molecular biologists in advanced laboratories and plant breeders and molecular biologists in the developing countries. The success of this CRP is evidenced by the introduction and application of new molecular methods by laboratories in developing countries, specially for the analysis of local crop genetic diversity. These exciting preliminary results show the potential for applications in crop improvement but much work remains to be done. Many of the vegetatively propagated species are ``orphan crops``, under-investigated on the international level. The development of new uses of transgenesis for the development of edible vaccines should not be overlooked. The challenge that remains is in the application of these new tools for practical end-user oriented improvements in vegetatively propagated crops. The present publication summarizes the third and final Research Co-ordination Meeting on the Use of Novel DNA Fingerprinting Techniques for the Detection and Characterization of Genetic Variation in Vegetatively Propagated Crops Refs, figs, tabs

  6. Ground Field-Based Hyperspectral Imaging: A Preliminary Study to Assess the Potential of Established Vegetation Indices to Infer Variation in Water-Use Efficiency.

    Science.gov (United States)

    Pelech, E. A.; McGrath, J.; Pederson, T.; Bernacchi, C.

    2017-12-01

    Increases in the global average temperature will consequently induce a higher occurrence of severe environmental conditions such as drought on arable land. To mitigate these threats, crops for fuel and food must be bred for higher water-use efficiencies (WUE). Defining genomic variation through high-throughput phenotypic analysis in field conditions has the potential to relieve the major bottleneck in linking desirable genetic traits to the associated phenotypic response. This can subsequently enable breeders to create new agricultural germplasm that supports the need for higher water-use efficient crops. From satellites to field-based aerial and ground sensors, the reflectance properties of vegetation measured by hyperspectral imaging is becoming a rapid high-throughput phenotyping technique. A variety of physiological traits can be inferred by regression analysis with leaf reflectance which is controlled by the properties and abundance of water, carbon, nitrogen and pigments. Although, given that the current established vegetation indices are designed to accentuate these properties from spectral reflectance, it becomes a challenge to infer relative measurements of WUE at a crop canopy scale without ground-truth data collection. This study aims to correlate established biomass and canopy-water-content indices with ground-truth data. Five bioenergy sorghum genotypes (Sorghum bicolor L. Moench) that have differences in WUE and wild-type Tobacco (Nicotiana tabacum var. Samsun) under irrigated and rainfed field conditions were examined. A linear regression analysis was conducted to determine if variation in canopy water content and biomass, driven by natural genotypic and artificial treatment influences, can be inferred using established vegetation indices. The results from this study will elucidate the ability of ground field-based hyperspectral imaging to assess variation in water content, biomass and water-use efficiency. This can lead to improved opportunities to

  7. Induced leaf variations in faba bean

    International Nuclear Information System (INIS)

    Yasin, M.

    1996-01-01

    The frequency and spectrum of M2 chlorophyll and other leaf mutations after gamma ray, ethyl methane sulfonate (EMS) and nitrous oxide (N2O) seed treatment in two varieties of faba bean were studied. In general, cv JV1 was more sensitive and EMS treatment was most effective. The frequency of chlorina-type mutations was higher than that of xantha and chlorotica type chlorophyll mutations. The highest frequency of variations was observed in leaflet texture, followed by arrangement, shape and size in both varieties. The use of these leaf mutations in formulating an ideotype of Vicia faba L. are discussed

  8. Evaporative cooling over the Tibetan Plateau induced by vegetation growth

    Science.gov (United States)

    Shen, Miaogen; Piao, Shilong; Jeong, Su-Jong; Zhou, Liming; Zeng, Zhenzhong; Ciais, Philippe; Chen, Deliang; Huang, Mengtian; Jin, Chun-Sil; Li, Laurent Z. X.; Li, Yue; Myneni, Ranga B.; Yang, Kun; Zhang, Gengxin; Zhang, Yangjian; Yao, Tandong

    2015-01-01

    In the Arctic, climate warming enhances vegetation activity by extending the length of the growing season and intensifying maximum rates of productivity. In turn, increased vegetation productivity reduces albedo, which causes a positive feedback on temperature. Over the Tibetan Plateau (TP), regional vegetation greening has also been observed in response to recent warming. Here, we show that in contrast to arctic regions, increased growing season vegetation activity over the TP may have attenuated surface warming. This negative feedback on growing season vegetation temperature is attributed to enhanced evapotranspiration (ET). The extra energy available at the surface, which results from lower albedo, is efficiently dissipated by evaporative cooling. The net effect is a decrease in daily maximum temperature and the diurnal temperature range, which is supported by statistical analyses of in situ observations and by decomposition of the surface energy budget. A daytime cooling effect from increased vegetation activity is also modeled from a set of regional weather research and forecasting (WRF) mesoscale model simulations, but with a magnitude smaller than observed, likely because the WRF model simulates a weaker ET enhancement. Our results suggest that actions to restore native grasslands in degraded areas, roughly one-third of the plateau, will both facilitate a sustainable ecological development in this region and have local climate cobenefits. More accurate simulations of the biophysical coupling between the land surface and the atmosphere are needed to help understand regional climate change over the TP, and possible larger scale feedbacks between climate in the TP and the Asian monsoon system. PMID:26170316

  9. Spatial variation in below ground carbon cycling in a pristine peatland, driven by present and past vegetation

    Science.gov (United States)

    Mathijssen, Paul; Knorr, Klaus-Holger; Gałka, Mariusz; Borken, Werner

    2017-04-01

    Peat carbon cycling is controlled by both large scale factors, such as climate and hydrological setting, and small scale factors, such as microtopography, vegetation, litter quality, and rooting depth. These small scale factors commonly vary within peatlands, causing variation in the carbon balance at different locations within the same site. Understanding the relationship between small scale carbon cycling and vegetation helps us to assess the variation of carbon dynamics of peatlands, because vegetation composition acts as an integrator of factors such as microtopography, hydrology, and nutrient level. Variation in vegetation illustrates spatial variation of these underlying factors. Furthermore, the presence of certain plant species affects carbon cycling directly through litter quality or aeration through root tissues. In order to understand these within-site variations in terms of carbon cycling, we investigated carbon accumulation, decomposition, and biogeochemistry of pore waters along a transect of peat cores with changing vegetation and water levels in an ombrotrophic peatland in southern Patagonia. The transect ran from a Sphagnum magellanicum dominated spot with relatively high water table, to intermediately wet spots with mixed Sphagnum/shrubs vegetation, or dominated by Cyperaceae, eventually to a more elevated and drier spot dominated by cushion plants (mainly Astelia pumila). There were large differences in peat accumulation rates and peat densities, with faster peat growth and lower densities under Sphagnum, but overall carbon accumulation rates were quite similar in the various microenvironments. At most plots C/N ratios decreased with depth, concurrent with increasing humification index derived from FT-IR spectra. But under cushion plants this relation was opposite: more humification with depth, but also C/N ratios increases. This reflected the differing source material at depth under the cushion plants, and that the cushion plant peat layers were

  10. Microbiological variation amongst fresh and minimally processed vegetables from retail establishers - a public health study in Pakistan

    Directory of Open Access Journals (Sweden)

    Sair, A.T.

    2017-07-01

    Full Text Available Fresh and minimally processed ready to eat vegetables are very attractive eatables amongst consumers as convenient, healthy and readily available foods, especially in the South Asian states. They provide numerous nutrients, phytochemicals, and vitamins but also harbor extensive quantity of potentially pathogenic bacteria. The aim of this study was to determine microbiological variation amongst fresh vegetables that were commercially available to the public at numerous retail establishments in Pakistan in order to present an overview of the quality of fresh produce. A total of 133 samples, collected from local distributors and retailers were tested for aerobic mesophilic and psychrotrophic, coliform and yeast and mould counts. Standard plating techniques were used to analyze all samples. Mesophilic count ranged from 3.1 to 10.3 log CFU/g with lowest and highest counts observed in onions and fresh cut vegetables. Psychrotrophic microorganisms count was as high as mesophilic microorganisms. Maximum counts for coliform were found in fresh cut vegetables with 100% samples falling over 6 log CFU/g. These results were consistent with yeast and moulds as well. In our study, Escherichia coli was determined as an indicator organism for 133 samples of fresh and minimally processed vegetables. Fresh cut vegetables showed the highest incidence of presumptive E. coli (69.9%. The results showed a poor quality of fresh vegetables in Pakistan and point to the implementation of good hygiene practices and food safety awareness amongst local distributors, food handlers at retail establishments.

  11. Variation in herbaceous vegetation and soil moisture under treated and untreated oneseed juniper trees

    Science.gov (United States)

    Hector Ramirez; Alexander Fernald; Andres Cibils; Michelle Morris; Shad Cox; Michael Rubio

    2008-01-01

    Clearing oneseed juniper (Juniperus monosperma) may make more water available for aquifer recharge or herbaceous vegetation growth, but the effects of tree treatment on soil moisture dynamics are not fully understood. This study investigated juniper treatment effects on understory herbaceous vegetation concurrently with soil moisture dynamics using vegetation sampling...

  12. On the sources of vegetation activity variation, and their relation with water balance in Mexico

    Science.gov (United States)

    F. Mora; L.R. Iverson

    1998-01-01

    Natural landscape surface processes are largely controlled by the relationship between climate and vegetation. Water balance integrates the effects of climate on patterns of vegetation distribution and productivity, and for that season, functional relationships can be established using water balance variables as predictors of vegetation response. In this study, we...

  13. Impact of 3D Canopy Structure on Remote Sensing Vegetation Index and Solar Induced Chlorophyll Fluorescence

    Science.gov (United States)

    Zeng, Y.; Berry, J. A.; Jing, L.; Qinhuo, L.

    2017-12-01

    Terrestrial ecosystem plays a critical role in removing CO2 from atmosphere by photosynthesis. Remote sensing provides a possible way to monitor the Gross Primary Production (GPP) at the global scale. Vegetation Indices (VI), e.g., NDVI and NIRv, and Solar Induced Fluorescence (SIF) have been widely used as a proxy for GPP, while the impact of 3D canopy structure on VI and SIF has not be comprehensively studied yet. In this research, firstly, a unified radiative transfer model for visible/near-infrared reflectance and solar induced chlorophyll fluorescence has been developed based on recollision probability and directional escape probability. Then, the impact of view angles, solar angles, weather conditions, leaf area index, and multi-layer leaf angle distribution (LAD) on VI and SIF has been studied. Results suggest that canopy structure plays a critical role in distorting pixel-scale remote sensing signal from leaf-scale scattering. In thin canopy, LAD affects both of the remote sensing estimated GPP and real GPP, while in dense canopy, SIF variations are mainly due to canopy structure, instead of just due to physiology. At the microscale, leaf angle reflects the plant strategy to light on the photosynthesis efficiency, and at the macroscale, a priori knowledge of leaf angle distribution for specific species can improve the global GPP estimation by remote sensing.

  14. Comparison of respiratory-induced variations in photoplethysmographic signals

    International Nuclear Information System (INIS)

    Li, Jin; Jin, Jie; Chen, Xiang; Sun, Weixin; Guo, Ping

    2010-01-01

    Photoplethysmography (PPG) is an optical method for detecting blood volume changes in tissue. Respiratory-induced intensity, frequency and amplitude variations are contained in the PPG signal; thus, an understanding of the relationships between all of these variations and respiration is essential to advancing respiration monitoring based on PPG. This study investigated correlations between respiratory-induced variations extracted from PPG and simultaneous respiratory signals. PPG signals were recorded from 28 healthy subjects under eight different conditions. Six respiratory-induced variations, i.e. the period of the systole, diastole and pulse, the amplitude of the systole and diastole, and the intensity variation, were determined from the PPG signal. The results indicate that, compared with the period of the pulse, the period of the systole and diastole correlates weakly with respiration; the amplitude of the diastole has a stronger correlation with respiration than the amplitude of the systole. For men, when the respiratory rate is less than 10 breaths min −1 , the period of the pulse has the strongest correlation with respiration, whereas up to or above 15 breaths min −1 , the intensity variation becomes strongest in the sitting posture, while the amplitude of the diastole is strongest in the supine posture. For women, compared with the other variations, the period of the pulse has nearly the strongest correlation with respiration, independent of respiratory rate or posture

  15. Drought-induced vegetation stress in southwestern North America

    International Nuclear Information System (INIS)

    Zhang Xiaoyang; Goldberg, Mitchell; Tarpley, Dan; Kogan, Felix; Yu Yunyue; Friedl, Mark A; Morisette, Jeffrey

    2010-01-01

    Trends towards earlier greenup and increased average greenness have been widely reported in both humid and dry ecosystems. By analyzing NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data from 1982 to 2007, we report complex trends in both the growing season amplitude and seasonally integrated vegetation greenness in southwestern North America and further highlight regions consistently experiencing drought stress. In particular, greenness measurements from 1982 to 2007 show an increasing trend in grasslands but a decreasing trend in shrublands. However, vegetation greenness in this period has experienced a strong cycle, increasing from 1982 to 1993 but decreasing from 1993 to 2007. The significant decrease during the last decade has reduced vegetation greenness by 6% in shrublands and 13% in grasslands (16% and 21%, respectively, in the severe drought years). The greenness cycle correlates to both annual precipitation and dry season length derived from NOAA North America Regional Reanalysis data. If drought events continue as predicted by climate models, they will exacerbate ecosystem degradation and reduce carbon uptake.

  16. The specificity of host-bat fly interaction networks across vegetation and seasonal variation.

    Science.gov (United States)

    Zarazúa-Carbajal, Mariana; Saldaña-Vázquez, Romeo A; Sandoval-Ruiz, César A; Stoner, Kathryn E; Benitez-Malvido, Julieta

    2016-10-01

    Vegetation type and seasonality promote changes in the species composition and abundance of parasite hosts. However, it is poorly known how these variables affect host-parasite interaction networks. This information is important to understand the dynamics of parasite-host relationships according to biotic and abiotic changes. We compared the specialization of host-bat fly interaction networks, as well as bat fly and host species composition between upland dry forest and riparian forest and between dry and rainy seasons in a tropical dry forest in Jalisco, Mexico. Bat flies were surveyed by direct collection from bats. Our results showed that host-bat fly interaction networks were more specialized in upland dry forest compared to riparian forest. Bat fly species composition was different between the dry and rainy seasons, while host species composition was different between upland dry forest and riparian forest. The higher specialization in upland dry forest could be related to the differences in bat host species composition and their respective roosting habits. Variation in the composition of bat fly species between dry and rainy seasons coincides with the seasonal shifts in their species richness. Our study confirms the high specialization of host-bat fly interactions and shows the importance of biotic and abiotic factors to understand the dynamics of parasite-host interactions.

  17. Hydraulic and Vegetative Models of Historic Environmental Conditions Isolate the Role of Riparian Vegetation in Inducing Channel Change

    Science.gov (United States)

    Manners, R.; Schmidt, J. C.; Wheaton, J. M.

    2011-12-01

    An enduring question in geomorphology is the role of riparian vegetation in inducing or exacerbating channel narrowing. It is typically difficult to isolate the role of vegetation in causing channel narrowing, because narrowing typically occurs where there are changes in stream flow, sediment supply, the invasion of non-native vegetation, and sometimes climate change. Therefore, linkages between changes in vegetation communities and changes in channel form are often difficult to identify. We took a mechanistic approach to isolate the role of the invasive riparian shrub tamarisk (Tamarix spp) in influencing channel narrowing in the Colorado River basin. Detailed geomorphic reconstructions of two sites on the Yampa and Green Rivers, respectively, in Dinosaur National Monument show that channel narrowing has been progressive and that tamarisk encroachment has also occurred; at the same time, dams have been constructed, diversions increased, and spring snowmelt runoff has been occurring earlier in spring. We simulated hydraulic and sediment transport conditions during the two largest floods of record -- 1984 and 2011. Two-dimensional hydraulic models were built to reflect these conditions and allowed us to perform sensitivity tests to determine the dominant determinants of the observed patterns of erosion and deposition. Channel and floodplain topography were constrained through detailed stratigraphic analysis, including precise dating of deposits based on dating of buried tamarisk plants in a series of floodplain trenches and pits. We also used historical air photos to establish past channel topography. To parameterize the influence of riparian vegetation, we developed a model that links detailed terrestrial laser scan (TLS) measurements of stand structure and its corresponding hydraulic roughness at the patch scale to reach-scale riparian vegetation patterns determined from airborne LiDaR (ALS). This model, in conjunction with maps of the ages and establishment

  18. Effects of spatial variations of soil moisture and vegetation on the evolution of a prestorm environment - A numerical case study

    Science.gov (United States)

    Chang, Jy-Tai; Wetzel, Peter J.

    1991-01-01

    To examine the effects of spatial variations of soil moisture and vegetation coverage on the evolution of a prestorm environment, the Goddard mesoscale model is modified to incorporate a simple evapotranspiration model that requires these two parameters. The case study of 3-4 June 1980 is of special interest due to the development of a tornado producing convective complex near Grand Island, Nebraska during a period of comparatively weak synoptic-scale forcing. It is shown that the observed stationary front was strongly enhanced by differential heating created by observed gradients of soil moisture, as acted upon by the vegetation cover.

  19. Consistency Between Sun-Induced Chlorophyll Fluorescence and Gross Primary Production of Vegetation in North America

    Science.gov (United States)

    Zhang, Yao; Xiao, Xiangming; Jin, Cui; Dong, Jinwei; Zhou, Sha; Wagle, Pradeep; Joiner, Joanna; Guanter, Luis; Zhang, Yongguang; Zhang , Geli; hide

    2016-01-01

    Accurate estimation of the gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study,we estimate GPP in North America (NA) using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS (Moderate Resolution Imaging Spectrometer) images at 8-day temporal and 500 meter spatial resolutions, and NCEP-NARR (National Center for Environmental Prediction-North America Regional Reanalysis) climate data. The simulated GPP (GPP (sub VPM)) agrees well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPP (sub VPM) in 2010 is spatially aggregated to 0.5 by 0.5-degree grid cells and then compared with sun-induced chlorophyll fluorescence (SIF) data from Global Ozone Monitoring Instrument 2 (GOME-2), which is directly related to vegetation photosynthesis. Spatial distribution and seasonal dynamics of GPP (sub VPM) and GOME-2 SIF show good consistency. At the biome scale, GPP (sub VPM) and SIF shows strong linear relationships (R (sup 2) is greater than 0.95) and small variations in regression slopes ((4.60-5.55 grams Carbon per square meter per day) divided by (milliwatts per square meter per nanometer per square radian)). The total annual GPP (sub VPM) in NA in 2010 is approximately 13.53 petagrams Carbon per year, which accounts for approximately 11.0 percent of the global terrestrial GPP and is within the range of annual GPP estimates from six other process-based and data-driven models (11.35-22.23 petagrams Carbon per year). Among the seven models, some models did not capture the spatial pattern of GOME-2 SIF data at annual scale, especially in Midwest cropland region. The results from this study demonstrate the reliable performance of VPM at the continental scale, and the potential of SIF data being used as a benchmark to compare with GPP models.

  20. Vegetation-Induced Roughness in Low-Reynold's Number Flows

    Science.gov (United States)

    Piercy, C. D.; Wynn, T. M.

    2008-12-01

    Wetlands are important ecosystems, providing habitat for wildlife and fish and shellfish production, water storage, erosion control, and water quality improvement and preservation. Models to estimate hydraulic resistance due to vegetation in emergent wetlands are crucial to good wetland design and analysis. The goal of this project is to improve modeling of emergent wetlands by linking properties of the vegetation to flow. Existing resistance equations such as Hoffmann (2004), Kadlec (1990), Moghadam and Kouwen (1997), Nepf (1999), and Stone and Shen (2002) were evaluated. A large outdoor vegetated flume was constructed at the Price's Fork Research Center near Blacksburg, Virginia to measure flow and water surface slope through woolgrass (Scirpus cyperinus), a common native emergent wetland plant. Measurements of clump and stem density, diameter, and volume, blockage factor, and stiffness were made after each set of flume runs. Flow rates through the flume were low (3-4 L/s) resulting in very low stem-Reynold's numbers (15-102). Since experimental flow conditions were in the laminar to transitional range, most of the models considered did not predict velocity or stage accurately except for conditions in which the stem-Reynold's number approached 100. At low stem-Reynold's numbers (drag coefficient is inversely proportional to the Reynold's number and can vary greatly with flow conditions. Most of the models considered assumed a stem-Reynold's number in the 100-105 range in which the drag coefficient is relatively constant and as a result did not predict velocity or stage accurately except for conditions in which the stem-Reynold's number approached 100. The only model that accurately predicted stem layer velocity was the Kadlec (1990) model since it does not make assumptions about flow regime; instead, the parameters are adjusted according to the site conditions. Future work includes relating the parameters used to fit the Kadlec (1990) model to measured vegetation

  1. Solar ultraviolet radiation induced variations in the stratosphere and mesosphere

    Science.gov (United States)

    Hood, L. L.

    1987-01-01

    The detectability and interpretation of short-term solar UV induced responses of middle atmospheric ozone, temperature, and dynamics are reviewed. The detectability of solar UV induced perturbations in the middle atmosphere is studied in terms of seasonal and endogenic dynamical variations. The interpretation of low-latitude ozone and possible temperature responses on the solar rotation time scale is examined. The use of these data to constrain or test photochemical model predictions is discussed.

  2. Variations in mountain vegetation use by reindeer (Rangifer tarandus) affects dry heath but not grass heath

    NARCIS (Netherlands)

    Moen, J.; Boogerd, C.; Skarin, A.

    2009-01-01

    Question: Are differences in landscape use of semi-domesticated reindeer reflected in the vegetation of summer grazing grounds? Location: Alpine heaths, central east Sweden. Methods: Dry heath and grass heath vegetation plots with inferred grazing intensities (high, intermediate and low) were

  3. Variations in fresh fruit and vegetable quality by store type, urban-rural setting and neighbourhood deprivation in Scotland.

    Science.gov (United States)

    Cummins, Steven; Smith, Dianna M; Taylor, Mathew; Dawson, John; Marshall, David; Sparks, Leigh; Anderson, Annie S

    2009-11-01

    Neighbourhood differences in access to fresh fruit and vegetables may explain social inequalities in diet. Investigations have focused on variations in cost and availability as barriers to the purchase and consumption of fresh produce; investigations of quality have been neglected. Here we investigate whether produce quality systematically varies by food store type, rural-urban location and neighbourhood deprivation in a selection of communities across Scotland. Cross-sectional survey of twelve fresh fruit and vegetable items in 288 food stores in ten communities across Scotland. Communities were selected to reflect a range of urban-rural settings and a food retail census was conducted in each location. The quality of twelve fruit and vegetable items within each food store was evaluated. Data from the Scottish Executive were used to characterise each small area by deprivation and urban-rural classification. Scotland. Quality of fruit and vegetables within the surveyed stores was high. Medium-sized stores, stores in small town and rural areas, and stores in more affluent areas tended to have the highest-quality fresh fruit and vegetables. Stores where food is secondary, stores in urban settings and stores in more deprived areas tended have the lowest-quality fresh produce. Although differences in quality were not always statistically significant, patterns were consistent for the majority of fruit and vegetable items. The study provides evidence that variations in food quality may plausibly be a micro-environmental mediating variable in food purchase and consumption and help partially explain neighbourhood differences in food consumption patterns.

  4. [Variation of forest vegetation carbon storage and carbon sequestration rate in Liaoning Province, Northeast China].

    Science.gov (United States)

    Zhen, Wei; Huang, Mei; Zhai, Yin-Li; Chen, Ke; Gong, Ya-Zhen

    2014-05-01

    The forest vegetation carbon stock and carbon sequestration rate in Liaoning Province, Northeast China, were predicted by using Canadian carbon balance model (CBM-CFS3) combining with the forest resource data. The future spatio-temporal distribution and trends of vegetation carbon storage, carbon density and carbon sequestration rate were projected, based on the two scenarios, i. e. with or without afforestation. The result suggested that the total forest vegetation carbon storage and carbon density in Liaoning Province in 2005 were 133.94 Tg and 25.08 t x hm(-2), respectively. The vegetation carbon storage in Quercus was the biggest, while in Robinia pseudoacacia was the least. Both Larix olgensis and broad-leaved forests had higher vegetation carbon densities than others, and the vegetation carbon densities of Pinus tabuliformis, Quercus and Robinia pseudoacacia were close to each other. The spatial distribution of forest vegetation carbon density in Liaoning Province showed a decrease trend from east to west. In the eastern forest area, the future increase of vegetation carbon density would be smaller than those in the northern forest area, because most of the forests in the former part were matured or over matured, while most of the forests in the later part were young. Under the scenario of no afforestation, the future increment of total forest vegetation carbon stock in Liaoning Province would increase gradually, and the total carbon sequestration rate would decrease, while they would both increase significantly under the afforestation scenario. Therefore, afforestation plays an important role in increasing vegetation carbon storage, carbon density and carbon sequestration rate.

  5. Nuclear level density variation with angular momentum induced shape transition

    International Nuclear Information System (INIS)

    Aggarwal, Mamta

    2016-01-01

    Variation of Nuclear level density (NLD) with the excitation energy and angular momentum in particular has been a topic of interest in the recent past and there have been continuous efforts in this direction on the theoretical and experimental fronts but a conclusive trend in the variation of nuclear level density parameter with angular momentum has not been achieved so far. A comprehensive investigation of N=68 isotones around the compound nucleus 119 Sb from neutron rich 112 Ru (Z=44) to neutron deficient 127 Pr (Z= 59) nuclei is presented to understand the angular momentum induced variations in inverse level density parameter and the possible influence of deformation and structural transitions on the variations on NLd

  6. Association analysis between spatiotemporal variation of vegetation greenness and precipitation/temperature in the Yangtze River Basin (China).

    Science.gov (United States)

    Cui, Lifang; Wang, Lunche; Singh, Ramesh P; Lai, Zhongping; Jiang, Liangliang; Yao, Rui

    2018-05-23

    The variation in vegetation greenness provides good understanding of the sustainable management and monitoring of land surface ecosystems. The present paper discusses the spatial-temporal changes in vegetation and controlling factors in the Yangtze River Basin (YRB) using Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) for the period 2001-2013. Theil-Sen Median trend analysis, Pearson correlation coefficients, and residual analysis have been used, which shows decreasing trend of the annual mean NDVI over the whole YRB. Spatially, the regions with significant decreasing trends were mainly located in parts of central YRB, and pronounced increasing trends were observed in parts of the eastern and western YRB. The mean NDVI during spring and summer seasons increased, while it decreased during autumn and winter seasons. The seasonal mean NDVI shows spatial heterogeneity due to the vegetation types. The correlation analysis shows a positive relation between NDVI and temperature over most of the YRB, whereas NDVI and precipitation show a negative correlation. The residual analysis shows an increase in NDVI in parts of eastern and western YRB and the decrease in NDVI in the small part of Yangtze River Delta (YRD) and the mid-western YRB due to human activities. In general, climate factors were the principal drivers of NDVI variation in YRB in recent years.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-15

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

  8. Spatiotemporal variations in vegetation cover on the Loess Plateau, China, between 1982 and 2013: possible causes and potential impacts.

    Science.gov (United States)

    Kong, Dongxian; Miao, Chiyuan; Borthwick, Alistair G L; Lei, Xiaohui; Li, Hu

    2018-03-02

    Vegetation is a key component of the ecosystem and plays an important role in water retention and resistance to soil erosion. In this study, we used a multiyear normalized difference vegetation index (NDVI) dataset (1982-2013) and corresponding datasets for observed climatic variables to analyze changes in the NDVI at both temporal and spatial scales. The relationships between NDVI, climate change, and human activities were also investigated. The annual average NDVI showed an upward trend over the 32-year study period, especially in the center of the Loess Plateau. NDVI variations lagged behind monthly temperature changes by approximately 1 month. The contribution of human activities to variations in NDVI has become increasingly significant in recent years, with human activities responsible for 30.4% of the change in NDVI during the period 2001-2013. The increased vegetation coverage has reduced soil erosion on the Loess Plateau in recent years. It is suggested that natural restoration of vegetation is the most effective measure for control of erosion; engineering measures that promote this should feature in the future governance of the Loess Plateau.

  9. Temperature and substrate controls on intra-annual variation in ecosystem respiration in two subarctic vegetation types

    DEFF Research Database (Denmark)

    Grogan, Paul; Jonasson, Sven Evert

    2005-01-01

    significantly to ecosystem respiration during most phases of winter and summer in the two vegetation types. Ecosystem respiration rates through the year did not differ significantly between vegetation types despite substantial differences in biomass pools, soil depth and temperature regime. Most (76...... contributions of bulk soil organic matter and plant-associated carbon pools to ecosystem respiration is critical to predicting the response of arctic ecosystem net carbon balance to climate change. In this study, we determined the variation in ecosystem respiration rates from birch forest understory and heath......-92%) of the intra-annual variation in ecosystem respiration rates from these two common mesic subarctic ecosystems was explained using a first-order exponential equation relating respiration to substrate chemical quality and soil temperature. Removal of plants and their current year's litter significantly reduced...

  10. Mangrove forests submitted to depositional processes and salinity variation investigated using satellite images and vegetation structure surveys

    OpenAIRE

    Cunha-Lignon, M.; Kampel, M.; Menghini, R.P.; Schaeffer-Novelli, Y.; Cintrón, G.; Dahdouh-Guebas, F.

    2011-01-01

    The current paper examines the growth and spatio-temporal variation of mangrove forests in response to depositional processes and different salinity conditions. Data from mangrove vegetation structure collected at permanent plots and satellite images were used. In the northern sector important environmental changes occurred due to an artificial channel producing modifications in salinity. The southern sector is considered the best conserved mangrove area along the coast of São Paulo State, Br...

  11. Understanding the variations in the vegetation of Cabo Frio, Southeastern coast of Brazil, during the Quaternary

    Science.gov (United States)

    Macario, K.; Coe, H. H.; Gomes, J.; Oliveira, F.; Gomes, P.; Carvalho, C.; Linares, R.; Alves, E.; Santos, G. M.

    2012-12-01

    The Brazilian Southeast was formerly occupied by Atlantic forest before the arrival of Europeans in the 16th century, when deforestation slowly started to take place. To understand the variations in the vegetation of Cabo Frio during the Quaternary, and possibly identify when they roughly took place, we make use of soil phytolith identification (as proxy), stable isotopes analyses and 14C dating of soil profiles. Nowadays, those are helpful tools to reveal the palaeoenvironmental secrets hidden below-ground. The soil profile studied, which was divided in 4 horizons ranging from 10 and 115 cm in depth, was collected in the surroundings of Cabo Frio, in the Rio de Janeiro (RJ), Southeastern coast of Brazil. Its total organic carbon (TOC) varied from 0.42 to 1.11% (for the different horizons), when its δ13C values ranged from -18.81 (topsoil) to -23.72‰ (~ 80cm deep). Phytolith D/P index varied from 0.1 to 0.21. Due to the low carbon content within soil horizons, soil organic matter (SOM) fractions were chosen for isotopic analyses. Mostly of the 14C-SOM analyses were performed in a newer 14C facility, which runs a NEC 250 kV Single Stage Accelerator Mass Spectrometry system, the Radiocarbon Laboratory of the Fluminense Federal University (LAC-UFF) located in Niteroi, RJ. In brief, before measurements could be performed, the soil samples were treated with HCl 1.0M to remove carbonates, then combusted in sealed evacuated pre-baked tubes, cryogenically clean and converted to graphite (as decribed in Xu et al. 2007). In order to verify the distribution of 14C ages of different chemical soil fractions (Pessenda et al. 2001), a refractory C fraction (humin) was extracted from the topsoil horizon, and also converted to graphite following established protocols (Santos et al. 2007a,b). Due to its very low carbon mass (measured at the Keck-CCAMS Facility at University of California, Irvine. (UCI), which runs a modified NEC AMS-system (NEC 0.5MV 1.5SDH-2 AMS system). Other

  12. Monitoring of oil palm plantations and growth variations with a dense vegetation model

    DEFF Research Database (Denmark)

    Teng, Khar Chun; Koay, Jun Yi; Tey, Seng Heng

    2014-01-01

    The development of microwave remote sensing models for the monitoring of vegetation has received wide attention in recent years. For vegetation in the tropics, it is necessary to consider a dense medium model for the theoretical modelling of the microwave interaction with the vegetation medium....... In this paper, a multilayer model based on the radiative transfer theory for a dense vegetation medium is developed where the coherence effects and near field interaction effects of closely spaced leaves and branches are considered by incorporating the Dense Medium Phase and Amplitude Correction Theory (DM......-PACT) and Fresnel Phase Corrections. The iterative solutions of the radiative transfer model are computed with input based on ground truth measurements of physical parameters of oil palm plantations in the state of Perak, Malaysia, and compared with the SAR images obtained from RADARSAT2. Preliminary results...

  13. Seasonal variations in phosphorus fractions in semiarid sandy soils under different vegetation types

    Science.gov (United States)

    Qiong Zhao; Dehui Zeng; Zhiping Fan; Zhanyuan Yu; Yalin Hu; Jianwei Zhang

    2009-01-01

    We investigated the seasonal patterns of soil phosphorus (P) fractions under five vegetation types – Ulmus macrocarpa savanna, grassland, Pinus sylvestris var. mongolica plantation, Pinus tabulaeformis plantation, and Populus simonii plantation ...

  14. Spatial variation in near-ground radiation and low temperature. Interactions with forest vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Blennow, K.

    1997-10-01

    Low temperature has a large impact on the survival and distribution of plants. Interactive effects with high irradiance lead to cold-induced photo inhibition, which may impact on the establishment and growth of tree seedlings. In this thesis, novel approaches are applied for relating the spatial variability in low temperature and irradiance to photosynthetic performance and growth of tree seedlings, and for modelling the micro- and local-scale spatial variations in low temperature for heterogeneous terrain. The methodologies include the development and use of a digital image analysis system for hemispherical photographs, the use of Geographic Information Systems (GIS) and statistical methods, field data acquisition of meteorological elements, plant structure, growth and photosynthetic performance. Temperature and amounts of intercepted direct radiant energy for seedlings on clear days (IDRE) were related to chlorophyll a fluorescence, and the dry weight of seedlings. The combination of increased IDRE with reduced minimum temperatures resulted in persistent and strong photo inhibition as the season progressed, with likely implications for the establishment of tree seedlings at forest edges, and within shelter wood. For models of spatial distribution of low air temperature, the sky view factor was used to parameterize the radiative cooling, whilst drainage, ponding and stagnation of cold air, and thermal properties of the ground were all considered. The models hint at which scales and processes govern the development of spatial variations in low temperature for the construction of corresponding mechanistic models. The methodology is well suited for detecting areas that will be frost prone after clearing of forest and for comparing the magnitudes of impacts on low air temperature of forest management practices, such as shelter wood and soil preparation. The results can be used to formulate ground rules for use in practical forestry 141 refs, 5 figs, 1 tab

  15. SEASONAL VARIATION IN LIGHT TRANSMISSION AND CANOPY GAPS OF DECIDUOUS ROADSIDE VEGETATION: ASSESSMENT WITHIN FOREST LANDSCAPE

    OpenAIRE

    Öztürk, Melih; Gökyer, Ercan

    2015-01-01

    Deciduous roadside vegetation exhibits seasonal patterns of foliage with varying colors and numbers. Hence the alternating percentage of the gaps within the roadside canopy allows changing percentages of light transmission throughout the year. The leafless roadside vegetation in winter is sequentially subject to budburst, flushing, and development stages until the summer, when the leaves are fully developed both in size and number. Then, defoliation follows senescence, and fading and fall sta...

  16. Metabolism of Mevalonic Acid in Vegetative and Induced Plants of Xanthium strumarium.

    Science.gov (United States)

    Bledsoe, C S

    1978-11-01

    The metabolism of mevalonic acid in Xanthium strumarium L. Chicago plants was studied to determine how mevalonate was metabolized and whether metabolism was related to induction of flowering. Leaves of vegetative, photoperiodically induced, and chemically inhibited cocklebur plants were supplied with [(14)C]mevalonic acid prior to or during a 16-hour inductive dark period. Vegetative, induced, and Tris(2-diethylaminoethyl)phosphate trihydrochloride-treated plants did not differ significantly in the amount of [(14)C]mevalonic acid they absorbed, nor in the distribution of radioactivity among the leaf blade (97%), petiole (2.3%), or shoot tip (0.7%). [(14)C]Mevalonic acid was rapidly metabolized and transported out of the leaves. Possible metabolites of mevalonate were mevalonic acid phosphates and sterols. No detectable (14)C was found in gibberellins, carotenoids, or the phytol alcohol of chlorophyll. Chemically inhibited plants accumulated (14)C compounds not found in vegetative or induced plants. When ethanol extracts of leaves, petioles, and buds were chromatographed, comparisons of chromatographic patterns did not show significant differences between vegetative and induced treatments.

  17. Metabolism of Mevalonic Acid in Vegetative and Induced Plants of Xanthium strumarium 1

    Science.gov (United States)

    Bledsoe, Caroline S.; Ross, Cleon W.

    1978-01-01

    The metabolism of mevalonic acid in Xanthium strumarium L. Chicago plants was studied to determine how mevalonate was metabolized and whether metabolism was related to induction of flowering. Leaves of vegetative, photoperiodically induced, and chemically inhibited cocklebur plants were supplied with [14C]mevalonic acid prior to or during a 16-hour inductive dark period. Vegetative, induced, and Tris(2-diethylaminoethyl)phosphate trihydrochloride-treated plants did not differ significantly in the amount of [14C]mevalonic acid they absorbed, nor in the distribution of radioactivity among the leaf blade (97%), petiole (2.3%), or shoot tip (0.7%). [14C]Mevalonic acid was rapidly metabolized and transported out of the leaves. Possible metabolites of mevalonate were mevalonic acid phosphates and sterols. No detectable 14C was found in gibberellins, carotenoids, or the phytol alcohol of chlorophyll. Chemically inhibited plants accumulated 14C compounds not found in vegetative or induced plants. When ethanol extracts of leaves, petioles, and buds were chromatographed, comparisons of chromatographic patterns did not show significant differences between vegetative and induced treatments. ImagesFig. 1 PMID:16660583

  18. Regular cell design approach considering lithography-induced process variations

    OpenAIRE

    Gómez Fernández, Sergio

    2014-01-01

    The deployment delays for EUVL, forces IC design to continue using 193nm wavelength lithography with innovative and costly techniques in order to faithfully print sub-wavelength features and combat lithography induced process variations. The effect of the lithography gap in current and upcoming technologies is to cause severe distortions due to optical diffraction in the printed patterns and thus degrading manufacturing yield. Therefore, a paradigm shift in layout design is mandatory towards ...

  19. Supplementary data: Variation in the PTEN-induced putative kinase ...

    Indian Academy of Sciences (India)

    Variation in the PTEN-induced putative kinase 1 gene associated with the increase risk of type 2 diabetes in northern Chinese. Yanchun Qu, Liang Sun, Ze Yang and Ruifa Han. J. Genet. 90, 125–128. Table 1. Clinical characteristics of cases and controls. Phenotype. T2DM. Controls. P value. Age (years). 49.5 ± 11.1. 50.4 ± ...

  20. Temporal variation (seasonal and interannual) of vegetation indices of maize and soybeans across multiple years in central Iowa

    Science.gov (United States)

    Prueger, J. H.; Hatfield, J. L.

    2015-09-01

    Remotely sensed reflectance parameters from corn and soybean surfaces can be correlated to crop production. Surface reflectance of a typical Upper Midwest corn /soybean region in central Iowa across multiple years reveal subtle dynamics in vegetative surface response to a continually varying climate. From 2006 through 2014 remotely sensed data have been acquired over production fields of corn and soybeans in central IA, U.S.A. with the fields alternating between corn and soybeans. The data have been acquired using ground-based radiometers with 16 wavebands covering the visible, near infrared, shortwave infrared wavebands and combined into a series of vegetative indices. These data were collected on clear days with the goal of collecting data at a minimum of once per week from prior to planting until after fall tillage operations. Within each field, five sites were established and sampled during the year to reduce spatial variation and allow for an assessment of changes in the vegetative indices throughout the growing season. Ancillary data collected for each crop included the phenological stage at each sampling date along with biomass sampled at the onset of the reproductive stage and at physiological maturity. Evaluation of the vegetative indices for the different years revealed that patterns were related to weather effects on corn and soybean growth. Remote sensing provides a method to evaluate changes within and among growing seasons to assess crop growth and development as affected by differences in weather variability.

  1. Gamma irradiation-induced variation in carrots (Daucus carota L.)

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Simon, P.W.

    1996-01-01

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue cultures, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type (reducing vs. non reducing sugars). Induced variation in root color and root shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment

  2. Gamma irradiation induced variation in carrots (Daucus Carota L.)

    International Nuclear Information System (INIS)

    Al-Safady, B.; Simon, P.W.

    1999-01-01

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M 1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue culture, were exposed to low doses of gamma irradiation. Higher doses reduced M 1 plant size by > 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M 1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M 2 families. Less variation was observed in total carotene content and none was seen in sugar type [reducing vs. non reducing sugars]. Induced variation in root color and rot shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M 2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M 2 somaclonal variation. Average root weight of M 2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment (Author)

  3. Induced variation in Jatropha curcas L.: status and scope

    International Nuclear Information System (INIS)

    Gour, V.K.; Sahu, Mamta; Prajapati, Vinod

    2006-01-01

    Full text: Jatropha curcas L. rich in reduced hydrocarbon, has become an important candidate for quality oil due to its convertibility in to bio-diesel and, suitability to sustain better in minimal resources makes it suitable for plantation in wastelands. It continued to evolve in varied agro-climatic niche through adaptation, natural selection and mutation in allogamous mode without directed selection across globe. Jatropha mission is one of the most promising and challenging ventures of the millennium to improve and make it economically viable as alternate crop for biofuel. The large collection of germplasm and its evaluation to reveal narrow phenotypic variability and scattered economic traits is an obvious challenge for the breeders to provide high yielding variety and suitability to varied environment. The basic objective is to induce variability and know the spectrum of variation to isolate traits of economic importance viz. floral changes with high proportion of pistillate flowers, tolerant to temporal changes, high capsule fertility, dwarfing, male sterility and high quality oil. The seeds of two provenances were induced with 60, 120, 180 and 240 Gy at BARC, Mumbai in the year 2004. The nursery was raised in the month of March 2004 and transplanted treatment wise to raise the M1 population. The M1 population across provenances and treatment exhibited plants with morphological variation and also through chimera. The major variations observed are for stem and foliage colour, narrow leaves, leaves without lobes, wavy margin and red petiole. The variation for proportion of male Vs female flowers and a plant with profuse flowering are desirable types. The spontaneous mutants isolated across 536 accessions raised in field gene bank exhibits variation for height (dwarf), stem succulence, hermaphrodites, dark green foliage and stem, leaves without lobes, branching from cotyledonary nodes (tri and tetra). The possibility of direct and indirect use of economic

  4. Multiscale mechanisms of nutritionally induced property variation in spider silks

    Science.gov (United States)

    Nobbs, Madeleine; Martens, Penny J.; Tso, I-Min; Chuang, Wei-Tsung; Chang, Chung-Kai; Sheu, Hwo-Shuenn

    2018-01-01

    Variability in spider major ampullate (MA) silk properties at different scales has proven difficult to determine and remains an obstacle to the development of synthetic fibers mimicking MA silk performance. A multitude of techniques may be used to measure multiscale aspects of silk properties. Here we fed five species of Araneoid spider solutions that either contained protein or were protein deprived and performed silk tensile tests, small and wide-angle X-ray scattering (SAXS/WAXS), amino acid composition analyses, and silk gene expression analyses, to resolve persistent questions about how nutrient deprivation induces variations in MA silk mechanical properties across scales. Our analyses found that the properties of each spider’s silk varied differently in response to variations in their protein intake. We found changes in the crystalline and non-crystalline nanostructures to play specific roles in inducing the property variations we found. Across treatment MaSp expression patterns differed in each of the five species. We found that in most species MaSp expression and amino acid composition variations did not conform with our predictions based on a traditional MaSp expression model. In general, changes to the silk’s alanine and proline compositions influenced the alignment of the proteins within the silk’s amorphous region, which influenced silk extensibility and toughness. Variations in structural alignment in the crystalline and non-crystalline regions influenced ultimate strength independent of genetic expression. Our study provides the deepest insights thus far into the mechanisms of how MA silk properties vary from gene expression to nanostructure formations to fiber mechanics. Such knowledge is imperative for promoting the production of synthetic silk fibers. PMID:29390013

  5. Variation in Metal Contents of Plants in Vegetable Garden Sites in ...

    African Journals Online (AJOL)

    The concentrations (mg/Kg) of Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn were determined in seven different vegetables which were obtained from sharada, kwakwachi and Jakara irrigation gardens in the Kano metropolis using Atomic Absorption Spectrophotometry (AAS). Samples were collected during both dry and rainy seasons.

  6. Variation in vegetation and microbial linkages with slope aspect in a montane temperate hardwood forest

    Czech Academy of Sciences Publication Activity Database

    Gilliam, F. S.; Hédl, Radim; Chudomelová, Markéta; McCulley, R. L.; Nelson, J. A.

    2014-01-01

    Roč. 5, č. 5 (2014), s. 1-17, A66 ISSN 2150-8925 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67985939 Keywords : vegetation * soil microorganisms * slope aspect Subject RIV: EH - Ecology, Behaviour Impact factor: 2.255, year: 2014

  7. Co-composting of vegetable wastes and carton: Effect of carton composition and parameter variations.

    Science.gov (United States)

    Rawoteea, Soonita Anjeena; Mudhoo, Ackmez; Kumar, Sunil

    2017-03-01

    The aim of the study was to investigate the effects of carton in the composting process of mixed vegetable wastes using an experimental composter of capacity 80L. Three different mixes were set-up (Mixes 1, 2 and 3) which consisted of vegetable wastes, 2.0kg paper and bulking agents, vegetable wastes, 1.5kg carton and bulking agents, vegetable wastes, 4.5kg carton and bulking agents, respectively. Temperature evolution, pH trends, moisture levels, respiration rates, percentage volatile solids and electrical conductivity were monitored for a period of 50days. The system remained under thermophilic conditions for a very short period due to the small size of the reactor. The three mixes did not exceed a temperature of 55°C, where sanitization takes place by the destruction of pathogens. The highest peak of CO 2 evolution was observed in Mix 2 indicating that maximum microbial degradation took place in that mix. Copyright © 2016. Published by Elsevier Ltd.

  8. Variation and Distribution of Glucosinolates in 42 Cultivars of Brassica oleracea Vegetable Crops

    NARCIS (Netherlands)

    Verkerk, R.; Tebbenhoff, S.; Dekker, M.

    2010-01-01

    Brassica vegetables are known to contain glucosinolates that are precursors for bioactive compounds like isothiocyanates that have been shown to play an important role in human health. This study reports the results of a screening of 11 Brassica oleracea crops consisting of 42 cultivars (6 white

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

    Directory of Open Access Journals (Sweden)

    Laura Ulsig

    2017-01-01

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

  10. Nutrient Deprivation Induces Property Variations in Spider Gluey Silk

    Science.gov (United States)

    Blamires, Sean J.; Sahni, Vasav; Dhinojwala, Ali; Blackledge, Todd A.; Tso, I-Min

    2014-01-01

    Understanding the mechanisms facilitating property variability in biological adhesives may promote biomimetic innovations. Spider gluey silks such as the spiral threads in orb webs and the gumfoot threads in cobwebs, both of which comprise of an axial thread coated by glue, are biological adhesives that have variable physical and chemical properties. Studies show that the physical and chemical properties of orb web gluey threads change when spiders are deprived of food. It is, however, unknown whether gumfoot threads undergo similar property variations when under nutritional stress. Here we tested whether protein deprivation induces similar variations in spiral and gumfoot thread morphology and stickiness. We manipulated protein intake for the orb web spider Nephila clavipes and the cobweb spider Latrodectus hesperus and measured the diameter, glue droplet volume, number of droplets per mm, axial thread width, thread stickiness and adhesive energy of their gluey silks. We found that the gluey silks of both species were stickier when the spiders were deprived of protein than when the spiders were fed protein. In N. clavipes a concomitant increase in glue droplet volume was found. Load-extension curves showed that protein deprivation induced glue property variations independent of the axial thread extensions in both species. We predicted that changes in salt composition of the glues were primarily responsible for the changes in stickiness of the silks, although changes in axial thread properties might also contribute. We, additionally, showed that N. clavipes' glue changes color under protein deprivation, probably as a consequence of changes to its biochemical composition. PMID:24523902

  11. Hydrological Networks and Associated Topographic Variation as Templates for the Spatial Organization of Tropical Forest Vegetation

    OpenAIRE

    Detto, Matteo; Muller-Landau, Helene C.; Mascaro, Joseph; Asner, Gregory P.

    2013-01-01

    An understanding of the spatial variability in tropical forest structure and biomass, and the mechanisms that underpin this variability, is critical for designing, interpreting, and upscaling field studies for regional carbon inventories. We investigated the spatial structure of tropical forest vegetation and its relationship to the hydrological network and associated topographic structure across spatial scales of 10-1000 m using high-resolution maps of LiDAR-derived mean canopy profile heigh...

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

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2017-09-01

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

  13. Variation in vegetable production among urban farmers in Ilorin, Kwara state, Nigeria

    Directory of Open Access Journals (Sweden)

    Yusuf, O.R.

    2012-12-01

    Full Text Available Urban agriculture in Nigerian cities has contributed immensely to provision of fresh vegetables and the overall food security in the urban space. Though this vegetable production takes place throughout the year, resource utilization that contributes to productivity among the various groups of urban cultivators is improperly understood. This paper addresses this issue in Ilorin, focusing on seventy farmers drawn from the two major groups of cultivators; Fadama and Okiti. Data were gathered through the use of focus group discussion (FGD, non participant observation, and questionnaire survey. Tabulation, percentages and trend description were employed in data analysis. Multiple Regression Analysis isolated utilization of pump machine, harvest from vegetable plots, utilization of modern input and type of labour used as the determinants of efficiency with a total percentage contribution of 89.6 to land-use, the major resource. Among the major findings is that the operational scale of Fadama cultivators is larger with a corresponding increase in profit compared to Okiti cultivators. It is also discovered that although the two systems are faced with similar constraints of environmental and inaccessibility to input problems, there exist some fundamental differences based on scale and production efficiency. Some solutions proffered to the identified problem include the recognition and integration of urban farmers into urban land use structure so that they can form cooperatives through which they can access productive inputs.

  14. Variation in Carotenoid Content of Kale and Other Vegetables: A Review of Pre- and Post-harvest Effects.

    Science.gov (United States)

    Walsh, Rachel P; Bartlett, Hannah; Eperjesi, Frank

    2015-11-11

    Lutein and zeaxanthin are carotenoids that are selectively taken up into the macula of the eye, where they are thought to protect against the development of age-related macular degeneration. They are obtained from dietary sources, with the highest concentrations found in dark green leafy vegetables, such as kale and spinach. In this Review, compositional variations due to variety/cultivar, stage of maturity, climate or season, farming practice, storage, and processing effects are highlighted. Only data from studies which report on lutein and zeaxanthin content in foods are reported. The main focus is kale; however, other predominantly xanthophyll containing vegetables such as spinach and broccoli are included. A small amount of data about exotic fruits is also referenced for comparison. The qualitative and quantitative composition of carotenoids in fruits and vegetables is known to vary with multiple factors. In kale, lutein and zeaxanthin levels are affected by pre-harvest effects such as maturity, climate, and farming practice. Further research is needed to determine the post-harvest processing and storage effects of lutein and zeaxanthin in kale; this will enable precise suggestions for increasing retinal levels of these nutrients.

  15. Potential influence of climate-induced vegetation shifts on future land use and associated land carbon fluxes in Northern Eurasia

    International Nuclear Information System (INIS)

    Kicklighter, D W; Melillo, J M; Lu, X; Cai, Y; Paltsev, S; Sokolov, A P; Reilly, J M; Zhuang, Q; Parfenova, E I; Tchebakova, N M

    2014-01-01

    Climate change will alter ecosystem metabolism and may lead to a redistribution of vegetation and changes in fire regimes in Northern Eurasia over the 21st century. Land management decisions will interact with these climate-driven changes to reshape the region’s landscape. Here we present an assessment of the potential consequences of climate change on land use and associated land carbon sink activity for Northern Eurasia in the context of climate-induced vegetation shifts. Under a ‘business-as-usual’ scenario, climate-induced vegetation shifts allow expansion of areas devoted to food crop production (15%) and pastures (39%) over the 21st century. Under a climate stabilization scenario, climate-induced vegetation shifts permit expansion of areas devoted to cellulosic biofuel production (25%) and pastures (21%), but reduce the expansion of areas devoted to food crop production by 10%. In both climate scenarios, vegetation shifts further reduce the areas devoted to timber production by 6–8% over this same time period. Fire associated with climate-induced vegetation shifts causes the region to become more of a carbon source than if no vegetation shifts occur. Consideration of the interactions between climate-induced vegetation shifts and human activities through a modeling framework has provided clues to how humans may be able to adapt to a changing world and identified the trade-offs, including unintended consequences, associated with proposed climate/energy policies. (paper)

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

    Science.gov (United States)

    Zhang, Xiaoyang; Tan, Bin; Yu, Yunyue

    2014-05-01

    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

  17. Role of Surface Wind and Vegetation Cover in Multi-decadal Variations of Dust Emission in the Sahara and Sahel

    Science.gov (United States)

    Kim, Dong; Chin, Mian; Remer, Lorraine A.; Diehl, Thomas L.; Bian, Huisheng; Yu, Hongbin; Brown, Molly E.; Stockwell, William R.

    2016-01-01

    North Africa, the world's largest dust source, is non-uniform, consisting of a permanently arid region (Sahara), a semi-arid region (Sahel), and a relatively moist vegetated region (Savanna), each with very different rainfall patterns and surface conditions. This study aims to better understand the controlling factors that determine the variation of dust emission in North Africa over a 27-year period from 1982 to 2008, using observational data and model simulations. The results show that the model-derived Saharan dust emission is only correlated with the 10-m winds (W10m) obtained from reanalysis data, but the model-derived Sahel dust emission is correlated with both W10m and the Normalized Difference Vegetation Index (NDVI) that is obtained from satellite. While the Saharan dust accounts for 82 of the continental North Africa dust emission (1340-1570 Tg year(exp -1) in the 27-year average, the Sahel accounts for 17 with a larger seasonal and inter-annual variation (230-380 Tg year(exp -1), contributing about a quarter of the transatlantic dust transported to the northern part of South America. The decreasing dust emission trend over the 27-year period is highly correlated with W10m over the Sahara (R equals 0.92). Over the Sahel, the dust emission is correlated with W10m (R 0.69) but is also anti-correlated with the trend of NDVI (R equals 0.65). W10m is decreasing over both the Sahara and the Sahel between 1982 and 2008, and the trends are correlated (R equals 0.53), suggesting that Saharan Sahelian surface winds are a coupled system, driving the inter-annual variation of dust emission.

  18. Neutrino induced decoherence and variation in nuclear decay rates

    International Nuclear Information System (INIS)

    Singleton, Douglas; Inan, Nader; Chiao, Raymond Y.

    2015-01-01

    Recent work has proposed that the interaction between ordinary matter and a stochastic gravitational background can lead to the decoherence of large aggregates of ordinary matter. In this work we point out that these arguments can be carried over to a stochastic neutrino background but with the Planck scale of the gravitational decoherence replaced by the weak scale. This implies that it might be possible to observe such neutrino induced decoherence on a small, microscopic system rather than a macroscopic system as is the case for gravitationally induced decoherence. In particular we suggest that neutrino decoherence could be linked with observed variations in the decay rates of certain nuclei. Finally we point out that this proposed neutrino induced decoherence can be considered the complement of the Mikheev–Smirnov–Wolfenstein (MSW) effect. - Highlights: • Review of decoherence arguments for matter moving in a stochastic gravitational background. • Application of these decoherence arguments to neutrinos and the weak interaction scale. • Suggestions of a connection between neutrino decoherence and variable nuclear decay rates. • Connection of neutron decoherence as the inverse of the MSW effect

  19. Detection of Minerals in Green Leafy Vegetables Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Shukla, P.; Kumar, R.; Raib, A. Kumar

    2016-11-01

    The distribution of minerals in different green leafy vegetables, such as spinach, chenopodium, chickpea, mustard, and fenugreek, was calculated using laser induced breakdown spectroscopy (LIBS). LIBS can provide an easy, reliable, efficient, low-cost, and in situ chemical analysis with a reasonable precision. In situ LIBS spectra in the range 200-500 nm were carried out using fresh leaves and leaves in the pellet form. As the spectra suggest, magnesium and calcium are present in each vegetable; however, the amount of them varies. It is observed that the amount of iron is maximal in spinach. The nutrition value of the plants was analyzed, and it was revealed that they are low in calories and fat and high in protein, fiber, iron, calcium, and phytochemicals.

  20. Morphodynamics structures induced by variations of the channel width

    Science.gov (United States)

    Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

    2014-05-01

    In alluvial channels, forcing effects, such as a longitudinally varying width, can induce the formation of steady bars (Olesen, 1984). The type of bars that form, such as alternate, central or multiple, will mainly depend on the local flow width-to-depth ratio and on upstream conditions (Struiksma et al., 1985). The effects on bar formation of varying the channel width received attention only recently and investigations, based on flume experiments and mathematical modelling, are mostly restricted to small longitudinal sinusoidal variations of the channel width (e.g. Repetto et al., 2002; Wu and Yeh, 2005, Zolezzi et al., 2012; Frascati and Lanzoni, 2013). In this work, we analyze the variations in equilibrium bed topography in a longitudinal width-varying channel with characteristic scales of the Waal River (The Netherlands) using two different 2D depth-averaged morphodynamic models, one based on the Delft3D code and one on Telemac-Mascaret system. In particular, we explore the effects of changing the wavelength of sinusoidal width variations in a straight channel, focusing on the effects of the spatial lag between bar formation and forcing that is observed in numerical models and laboratory experiments (e.g. Crosato et al, 2011). We extend the investigations to finite width variations in which longitudinal changes of the width-to-depth ratio are such that they may affect the type of bars that become unstable (alternate, central or multiple bars). Numerical results are qualitatively validated with field observations and the resulting morphodynamic pattern is compared with the physics-based predictor of river bar modes by Crosato and Mosselman (2009). The numerical models are finally used to analyse the experimental conditions of Wu and Yeh (2005). The study should be seen as merely exploratory. The aim is to investigate possible approaches for future research aiming at assessing the effects of artificial river widening and narrowing to control bar formation in

  1. Spatial variation and linkages of soil and vegetation in the Siberian Arctic tundra - coupling field observations with remote sensing data

    Science.gov (United States)

    Mikola, Juha; Virtanen, Tarmo; Linkosalmi, Maiju; Vähä, Emmi; Nyman, Johanna; Postanogova, Olga; Räsänen, Aleksi; Kotze, D. Johan; Laurila, Tuomas; Juutinen, Sari; Kondratyev, Vladimir; Aurela, Mika

    2018-05-01

    Arctic tundra ecosystems will play a key role in future climate change due to intensifying permafrost thawing, plant growth and ecosystem carbon exchange, but monitoring these changes may be challenging due to the heterogeneity of Arctic landscapes. We examined spatial variation and linkages of soil and plant attributes in a site of Siberian Arctic tundra in Tiksi, northeast Russia, and evaluated possibilities to capture this variation by remote sensing for the benefit of carbon exchange measurements and landscape extrapolation. We distinguished nine land cover types (LCTs) and to characterize them, sampled 92 study plots for plant and soil attributes in 2014. Moreover, to test if variation in plant and soil attributes can be detected using remote sensing, we produced a normalized difference vegetation index (NDVI) and topographical parameters for each study plot using three very high spatial resolution multispectral satellite images. We found that soils ranged from mineral soils in bare soil and lichen tundra LCTs to soils of high percentage of organic matter (OM) in graminoid tundra, bog, dry fen and wet fen. OM content of the top soil was on average 14 g dm-3 in bare soil and lichen tundra and 89 g dm-3 in other LCTs. Total moss biomass varied from 0 to 820 g m-2, total vascular shoot mass from 7 to 112 g m-2 and vascular leaf area index (LAI) from 0.04 to 0.95 among LCTs. In late summer, soil temperatures at 15 cm depth were on average 14 °C in bare soil and lichen tundra, and varied from 5 to 9 °C in other LCTs. On average, depth of the biologically active, unfrozen soil layer doubled from early July to mid-August. When contrasted across study plots, moss biomass was positively associated with soil OM % and OM content and negatively associated with soil temperature, explaining 14-34 % of variation. Vascular shoot mass and LAI were also positively associated with soil OM content, and LAI with active layer depth, but only explained 6-15 % of variation. NDVI

  2. Variation in spread of Heterobasidion annosum in clones of Picea abies grown at different vegetation phases under greenhouse conditions

    Energy Technology Data Exchange (ETDEWEB)

    Svedjemark, G.; Stenlid, J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1996-06-01

    Forty-nine Picea abies (L.) Karst clones were inoculated under greenhouse conditions with a Heterobasidion annosum (Fr.) Bref. isolate of the S intersterility group. The cuttings were inoculated at the following vegetation stages; bud-flushing stage, vegetative stage and after bud-set. Fungal growth in sapwood and leison length in the inner bark were measured after 34 days. The susceptibility of the various clones to H. annosum was strongly correlated among the three vegetation stages, both in terms of mean growth and mean growth ranking. Partitioning of variance components showed that variation in growth was explained by physiological stages and clone to 4% and 24%, respectively, and for interaction between clone and physiological stage to 9%. Corresponding values for leison length in the inner bark were 3%, 14% and 5%, respectively. Fungal growth in wood and leison length in the inner bark were strongly correlated (r{sup 2} ranging between 0.23 and 0.36). When cuttings were inoculated during bud-flushing, leison length and fungal growth in wood were both strongly correlated with bud-flushing index of the cuttings (r{sup 2} = 0.03 and 0.04 respectively) but that was not the case for the other stages. The number of active fine-roots and the degree of wilting of the cuttings were negatively correlated with leison length and fungal growth (r{sup 2} ranging between 0.01 and 0.13). Height and diameter varied greatly between the clones and both were negatively correlated with fungal extension (r{sup 2} ranging between 0.01 and 0.09). 33 refs, 2 figs, 3 tabs

  3. Study on Climatic Variation and Its Effect on Vegetable Type Soybean Genotypes at Khumaltar, Lalitpur in the Last Ten Years

    Directory of Open Access Journals (Sweden)

    Santosh Raj Tripathi

    2015-04-01

    Full Text Available Soybean (Glycine max L. Merril is widely grown in the mid hills as intercrop with maize or in paddy bunds, while it is gaining popularity as sole crop in terai and inner terai. Mean temperature at Khumaltar during soybean growing period was mostly fluctuating; but we observed an increasing trend in temperature. Amount of rainfall was not changed dramatically but number of rainy days was decreased during study period. Rainfall during germination time increase soil moisture which also increase germination and found higher early stand. Days from sowing to 50% flowering and 90% maturity were short in the case of higher minimum temperature and low rainfall. Among the genotypes, AGS-377, AGS-378, AGS-379 and Tarkari Bhattmas-1 were more sensitive. However, seed yield decreased in the case of higher temperatures and low rainfall. Cool night temperatures and high moisture increased disease incidence in soybean which, eventually reduced yield. In last three years, plant suffered from moisture stress during early vegetative stage and high moisture during late vegetative stage which reduced seed yield and seed weight. In conclusion, we found that genotypes like AGS- 360, Sathiya and Tarkari Bhatmas-1 are very sensitive to climatic variation.

  4. Diversity in plant hydraulic traits explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests.

    Science.gov (United States)

    Xu, Xiangtao; Medvigy, David; Powers, Jennifer S; Becknell, Justin M; Guan, Kaiyu

    2016-10-01

    We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests (SDTFs). The Ecosystem Demography model 2 (ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America. The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index (LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America. Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  5. Spatio-temporal variation of vegetation coverage and its response to climate change in North China plain in the last 33 years

    Science.gov (United States)

    A, Duo; Zhao, Wenji; Qu, Xinyuan; Jing, Ran; Xiong, Kai

    2016-12-01

    Global climate change has led to significant vegetation changes in the past half century. North China Plain, the most important grain production base of china, is undergoing a process of prominent warming and drying. The vegetation coverage, which is used to monitor vegetation change, can respond to climate change (temperature and precipitation). In this study, GIMMS (Global Inventory Modelling and Mapping Studies)-NDVI (Normalized Difference Vegetation Index) data, MODIS (Moderate-resolution Imaging Spectroradiometer) - NDVI data and climate data, during 1981-2013, were used to investigate the spatial distribution and changes of vegetation. The relationship between climate and vegetation on different spatial (agriculture, forest and grassland) and temporal (yearly, decadal and monthly) scales were also analyzed in North China Plain. (1) It was found that temperature exhibiting a slight increase trend (0.20 °C/10a, P 0.05). The climate mutation period was during 1991-1994. (2) Vegetation coverage slight increase was observed in the 55% of total study area, with a change rate of 0.00039/10a. Human activities may not only accelerate the changes of the vegetation coverage, but also c effect to the rate of these changes. (3) Overall, the correlation between the vegetation coverage and climatic factor is higher in monthly scale than yearly scale. The correlation analysis between vegetation coverage and climate changes showed that annual vegetation coverage was better correlatend with precipitation in grassland biome; but it showed a better correlated with temperature i the agriculture biome and forest biome. In addition, the vegetation coverage had sensitive time-effect respond to precipitation. (4) The vegetation coverage showed the same increasing trend before and after the climatic variations, but the rate of increase slowed down. From the vegetation coverage point of view, the grassland ecological zone had an obvious response to the climatic variations, but the

  6. Variations in annual water-energy balance and their correlations with vegetation and soil moisture dynamics: A case study in the Wei River Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shengzhi; Huang, Qiang; Leng, Guoyong; Zhao, Menglong; Meng, Erhao

    2017-03-01

    It is of importance to investigate watershed water-energy balance variations and to explore their correlations with vegetation and soil moisture dynamics, which helps better understand the interplays between underlying surface dynamics and the terrestrial water cycle. The heuristic segmentation method was adopted to identify change points in the parameter to series in Fu's equation belonging to the Budyko framework in the Wei River Basin (WRB) and its sub-basins aiming to examine the validity of stationary assumptions. Additionally, the cross wavelet analysis was applied to explore the correlations between vegetation and soil moisture dynamics and to variations. Results indicated that (1) the omega variations in the WRB are significant, with some change points identified except for the sub-basin above Zhangjiashan, implying that the stationarity of omega series in the WRB is invalid except for the sub-basin above Zhangjiashan; (2) the correlations between soil moisture series and to series are weaker than those between Normalized Difference Vegetation Index (NDVI) series and omega series; (3) vegetation dynamics show significantly negative correlations with omega variations in 1983-2003 with a 4-8 year signal in the whole WRB, and both vegetation and soil moisture dynamics exert strong impacts on the parameter omega changes. This study helps understanding the interactions between underlying land surface dynamics and watershed water-energy balance. (C) 2017 Elsevier B.V. All rights reserved.

  7. Evaluation of Spatiotemporal Variations of Global Fractional Vegetation Cover Based on GIMMS NDVI Data from 1982 to 2011

    Directory of Open Access Journals (Sweden)

    Donghai Wu

    2014-05-01

    Full Text Available Fractional vegetation cover (FVC is an important biophysical parameter of terrestrial ecosystems. Variation of FVC is a major problem in research fields related to remote sensing applications. In this study, the global FVC from 1982 to 2011 was estimated by GIMMS NDVI data, USGS global land cover characteristics data and HWSD soil type data with a modified dimidiate pixel model, which considered vegetation and soil types and mixed pixels decomposition. The evaluation of the robustness and accuracy of the GIMMS FVC with MODIS FVC and Validation of Land European Remote sensing Instruments (VALERI FVC show high reliability. Trends of the annual FVCmax and FVCmean datasets in the last 30 years were reported by the Mann–Kendall method and Sen’s slope estimator. The results indicated that global FVC change was 0.20 and 0.60 in a year with obvious seasonal variability. All of the continents in the world experience a change in the annual FVCmax and FVCmean, which represents biomass production, except for Oceania, which exhibited a significant increase based on a significance level of p = 0.001 with the Student’s t-test. Global annual maximum and mean FVC growth rates are 0.14%/y and 0.12%/y, respectively. The trends of the annual FVCmax and FVCmean based on pixels also illustrated that the global vegetation had turned green in the last 30 years. A significant trend on the p = 0.05 level was found for 15.36% of the GIMMS FVCmax pixels on a global scale (excluding permanent snow and ice, in which 1.8% exhibited negative trends and 13.56% exhibited positive trends. The GIMMS FVCmean similarly produced a total of 16.64% significant pixels with 2.28% with a negative trend and 14.36% with a positive trend. The North Frigid Zone represented the highest annual FVCmax significant increase (p = 0.05 of 25.17%, which may be caused mainly by global warming, Arctic sea-ice loss and an advance in growing seasons. Better FVC predictions at large regional scales

  8. Kinetics of heat-induced color change of a tuna-vegetable mixture

    OpenAIRE

    Scherer, Erika; Sandoval, Aleida J; Barreiro, José A

    2009-01-01

    Heat induced color change kinetics in a tuna-vegetable mixture was evaluated by measuring color parameter "L" (Hunter-Lab) and 5-hydroxi-methyl-furfural (5-HMF) accumulation. For this purpose small reusable stainless steel TDT cans were used and the kinetic studies performed in a temperature range characteristic of thermal processing of low acid canned foods (110-125°C). The color parameter L was better described by a pseudo zero order while a pseudo first order reaction was found for 5-HMF a...

  9. Effects of future climate change, CO2 enrichment, and vegetation structure variation on hydrological processes in China

    Science.gov (United States)

    Zhu, Qiuan; Jiang, Hong; Peng, Changhui; Liu, Jinxun; Fang, Xiuqin; Wei, Xiaohua; Liu, Shirong; Zhou, Guomo

    2012-01-01

    Investigating the relationship between factors (climate change, atmospheric CO2 concentrations enrichment, and vegetation structure) and hydrological processes is important for understanding and predicting the interaction between the hydrosphere and biosphere. The Integrated Biosphere Simulator (IBIS) was used to evaluate the effects of climate change, rising CO2, and vegetation structure on hydrological processes in China at the end of the 21st century. Seven simulations were implemented using the assemblage of the IPCC climate and CO2 concentration scenarios, SRES A2 and SRES B1. Analysis results suggest that (1) climate change will have increasing effects on runoff, evapotranspiration (ET), transpiration (T), and transpiration ratio (transpiration/evapotranspiration, T/E) in most hydrological regions of China except in the southernmost regions; (2) elevated CO2 concentrations will have increasing effects on runoff at the national scale, but at the hydrological region scale, the physiology effects induced by elevated CO2 concentration will depend on the vegetation types, climate conditions, and geographical background information with noticeable decreasing effects shown in the arid Inland region of China; (3) leaf area index (LAI) compensation effect and stomatal closure effect are the dominant factors on runoff in the arid Inland region and southern moist hydrological regions, respectively; (4) the magnitudes of climate change (especially the changing precipitation pattern) effects on the water cycle are much larger than those of the elevated CO2 concentration effects; however, increasing CO2 concentration will be one of the most important modifiers to the water cycle; (5) the water resource condition will be improved in northern China but depressed in southernmost China under the IPCC climate change scenarios, SRES A2 and SRES B1.

  10. Holocene vegetation and climatic variations in Central India: A study based on multiproxy evidences

    Science.gov (United States)

    Chauhan, M. S.; Sharma, Anupam; Phartiyal, Binita; Kumar, Kamlesh

    2013-11-01

    Palynology, texture, mineralogy, geochemistry, and magnetic susceptibility analysis of a 2 m deep sediment core from Padauna Swamp, southeastern Madhya Pradesh infers that between 8600 and 7500 cal yr BP a warm and relatively less-humid climate prevailed with open tree-savannahs dominated by grasses followed by sedges, Artemisia and members of Chenopodiaceae/Amaranthaceae with scanty trees viz., Schrebera, Aegle marmelos and Sterculia urens. This is well supported by lower organic to carbonate carbon ratio, coarser texture having relatively low CIA and magnetic susceptibility values and presence of some primary minerals. Between 7500 and 6250 cal yr BP the tree-savannahs were succeeded by open mixed deciduous forests with the invasion of a few more trees viz., Madhuca indica, Holoptelea, Emblica officinalis, Mitragyna parvifolia and members of Anacardiaceae in response to onset of a warm and humid climate. A considerable rise in organic carbon generated from the degradation of plentiful biomass along with increase in clay content with signs of kaolinite and increase in immobile over mobile elements with slightly higher CIA and magnetic susceptibility values also suggest climatic amelioration. The presence of ruderal plants such as Artemisia, Cannabis sativa and Cheno/Am further infers initiation of human activities in the region. Between 6250 and 2800 cal yr BP, the mixed deciduous forests became more diverse and dense, subduing grasses and other herbaceous elements. Sporadic incursion of Shorea robusta (Sal) in forest floristic was recorded around 5000 cal yr BP. The overall change in the vegetation mosaic reflects that a warm and more-humid climate prevailed in the region, probably on account of invigoration of southwest monsoon. This observation is further corroborated by other proxy data showing a spurt in organic/inorganic carbon ratio, increase in clay content with matured mineralogy, significantly higher CIA and magnetic susceptibility values. Since 2800 cal

  11. Vegetation-induced spatial variability of soil redox properties in wetlands

    Science.gov (United States)

    Szalai, Zoltán; Jakab, Gergely; Kiss, Klaudia; Ringer, Marianna; Balázs, Réka; Zacháry, Dóra; Horváth Szabó, Kata; Perényi, Katalin

    2016-04-01

    Vegetation induced land patches may result spatial pattern of on soil Eh and pH. These spatial pattern are mainly emerged by differences of aeration and exudation of assimilates. Present paper focuses on vertical extent and temporal dynamics of these patterns in wetlands. Two study sites were selected: 1. a plain wetland on calcareous sandy parent material (Ceglédbercel, Danube-Tisza Interfluve, Hungary); 2. headwater wetland with calcareous loamy parent material (Bátaapáti, Hungary). Two vegetation patches were studied in site 1: sedgy (dominated by Carex riparia) and reedy (dominated by Phragmites australis). Three patches were studied in site2: sedgy1 (dominated by C vulpina), sedgy 2 (C. riparia); nettle-horsetail (Urtica dioica and Equisetum arvense). Boundaries between patches were studied separately. Soil redox, pH and temperature studied by automated remote controlled instruments. Three digital sensors (Ponsell) were installed in each locations: 20cm and 40cm sensors represent the solum and 100 cm sensor monitors the subsoil). Groundwater wells were installed near to triplets for soil water sampling. Soil Eh, pH and temperature values were recorded in each 10 minutes. Soil water sampling for iron and DOC were carried out during saturated periods. Spatial pattern of soil Eh is clearly caused by vegetation. We measured significant differences between Eh values of the studied patches in the solum. We did not find this kinds horizontal differences in the subsoil. Boundaries of the patches usually had more reductive soil environment than the core areas. We have found temporal dynamics of the spatial redox pattern. Differences were not so well expressed during wintertime. These spatial patterns had influence on the DOC and iron content of porewater, as well. Highest temporal dynamics of soil redox properties and porewater iron could be found in the boundaries. These observations refer to importance patchiness of vegetation on soil chemical properties in

  12. Vegetation-induced turbulence influencing evapotranspiration-soil moisture coupling: Implications for semiarid regions

    Science.gov (United States)

    Haghighi, E.; Kirchner, J. W.; Entekhabi, D.

    2016-12-01

    The relationship between soil moisture and evapotranspiration (ET) fluxes is an important component of land-atmosphere interactions controlling hydrology-climate feedback processes. Important as this relationship is, it remains empirical and physical mechanisms governing its dynamics are insufficiently studied. This is particularly of importance for semiarid regions (currently comprising about half of the Earth's land surface) where the shallow surface soil layer is the primary source of ET and direct evaporation from bare soil is likely a large component of the total flux. Hence, ET-soil moisture coupling in these regions is hypothesized to be strongly influenced by soil evaporation and associated mechanisms. Motivated by recent progress in mechanistic modeling of localized heat and mass exchange rates from bare soil surfaces covered by cylindrical bluff-body elements, we developed a physically based ET model explicitly incorporating coupled impacts of soil moisture and vegetation-induced turbulence in the near-surface region. Model predictions of ET and its partitioning were in good agreement with measured data and suggest that the strength and nature of ET-soil moisture interactions in sparsely vegetated areas are strongly influenced by aerodynamic (rather than radiative) forcing namely wind speed and near-surface turbulence generation as a function of vegetation type and cover fraction. The results demonstrated that the relationship between ET and soil moisture varies from a nonlinear function (the dual regime behavior) to a single moisture-limited regime (linear relationship) by increasing wind velocity and enhancing turbulence generation in the near-surface region (small-scale woody vegetation species of low cover fraction). Potential benefits of this study for improving accuracy and predictive capabilities of remote sensing techniques when applied to semiarid environments will also be discussed.

  13. Vegetation greenness and land carbon-flux anomalies associated with climate variations: a focus on the year 2015

    Directory of Open Access Journals (Sweden)

    C. Yue

    2017-11-01

    Full Text Available Understanding the variations in global land carbon uptake, and their driving mechanisms, is essential if we are to predict future carbon-cycle feedbacks on global environmental changes. Satellite observations of vegetation greenness have shown consistent greening across the globe over the past three decades. Such greening has driven the increasing land carbon sink, especially over the growing season in northern latitudes. On the other hand, interannual variations in land carbon uptake are strongly influenced by El Niño–Southern Oscillation (ENSO climate variations. Marked reductions in land uptake and strong positive anomalies in the atmospheric CO2 growth rates occur during El Niño events. Here we use the year 2015 as a natural experiment to examine the possible response of land ecosystems to a combination of vegetation greening and an El Niño event. The year 2015 was the greenest year since 2000 according to satellite observations, but a record atmospheric CO2 growth rate also occurred due to a weaker than usual land carbon sink. Two atmospheric inversions indicate that the year 2015 had a higher than usual northern land carbon uptake in boreal spring and summer, consistent with the positive greening anomaly and strong warming. This strong uptake was, however, followed by a larger source of CO2 in the autumn. For the year 2015, enhanced autumn carbon release clearly offset the extra uptake associated with greening during the summer. This finding leads us to speculate that a long-term greening trend may foster more uptakes during the growing season, but no large increase in annual carbon sequestration. For the tropics and Southern Hemisphere, a strong transition towards a large carbon source for the last 3 months of 2015 is discovered, concomitant with El Niño development. This transition of terrestrial tropical CO2 fluxes between two consecutive seasons is the largest ever found in the inversion records. The strong transition to a

  14. Vegetation greenness and land carbon-flux anomalies associated with climate variations: a focus on the year 2015

    Science.gov (United States)

    Yue, Chao; Ciais, Philippe; Bastos, Ana; Chevallier, Frederic; Yin, Yi; Rödenbeck, Christian; Park, Taejin

    2017-11-01

    Understanding the variations in global land carbon uptake, and their driving mechanisms, is essential if we are to predict future carbon-cycle feedbacks on global environmental changes. Satellite observations of vegetation greenness have shown consistent greening across the globe over the past three decades. Such greening has driven the increasing land carbon sink, especially over the growing season in northern latitudes. On the other hand, interannual variations in land carbon uptake are strongly influenced by El Niño-Southern Oscillation (ENSO) climate variations. Marked reductions in land uptake and strong positive anomalies in the atmospheric CO2 growth rates occur during El Niño events. Here we use the year 2015 as a natural experiment to examine the possible response of land ecosystems to a combination of vegetation greening and an El Niño event. The year 2015 was the greenest year since 2000 according to satellite observations, but a record atmospheric CO2 growth rate also occurred due to a weaker than usual land carbon sink. Two atmospheric inversions indicate that the year 2015 had a higher than usual northern land carbon uptake in boreal spring and summer, consistent with the positive greening anomaly and strong warming. This strong uptake was, however, followed by a larger source of CO2 in the autumn. For the year 2015, enhanced autumn carbon release clearly offset the extra uptake associated with greening during the summer. This finding leads us to speculate that a long-term greening trend may foster more uptakes during the growing season, but no large increase in annual carbon sequestration. For the tropics and Southern Hemisphere, a strong transition towards a large carbon source for the last 3 months of 2015 is discovered, concomitant with El Niño development. This transition of terrestrial tropical CO2 fluxes between two consecutive seasons is the largest ever found in the inversion records. The strong transition to a carbon source in the

  15. Flume experiments on wind induced flow in static water bodies in the presence of protruding vegetation

    Science.gov (United States)

    Banerjee, Tirtha; Muste, Marian; Katul, Gabriel

    2015-02-01

    The problem of wind-induced flow in inland waters is drawing significant research attention given its relevance to a plethora of applications in wetlands including treatment designs, pollution reduction, and biogeochemical cycling. The present work addresses the role of wind induced turbulence and waves within an otherwise static water body in the presence of rigid and flexible emergent vegetation through flume experimentation and time series analysis. Because no prior example of Particle Imaging Velocimetry (PIV) experiments involving air-water and flexible oscillating components have been found in the literature, a spectral analysis framework is needed and proposed here to guide the analysis involving noise, wave and turbulence separation. The experiments reveal that wave and turbulence effects are simultaneously produced at the air-water interface and the nature of their coexistence is found to vary with different flow parameters including water level, mean wind speed, vegetation density and its flexibility. For deep water levels, signature of fine-scaled inertial turbulence is found at deeper layers of the water system. The wave action appears stronger close to the air-water interface and damped by the turbulence deeper inside the water system. As expected, wave action is found to be dominated in a certain frequency range driven by the wind forcing, while it is also diffused to lower frequencies by means of (wind-induced) oscillations in vegetation. Regarding the mean water velocity, existence of a counter-current flow and its switching to fully forward flow in the direction of the wind under certain combinations of flow parameters were studied. The relative importance of wave and turbulence to the overall energy, degree of anisotropy in the turbulent energy components, and turbulent momentum transport at different depths from the air-water interface and flow combinations were then quantified. The flume experiments reported here differ from previous laboratory

  16. How spatial variation in areal extent and configuration of labile vegetation states affect the riparian bird community in Arctic tundra.

    Directory of Open Access Journals (Sweden)

    John-André Henden

    Full Text Available The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond rapidly to both abiotic and biotic environmental drivers. Our aim was to assess how large-scale spatial variation in willow thicket areal extent, configuration and habitat structure affected bird abundance, occupancy rates and species richness so as to provide an empirical basis for predicting the outcome of environmental change for riparian tundra bird communities. Based on a 4-year count data series, obtained through a large-scale study design in low arctic tundra in northern Norway, statistical hierarchical community models were deployed to assess relations between habitat configuration and bird species occupancy and community richness. We found that species abundance, occupancy and richness were greatly affected by willow areal extent and configuration, habitat features likely to be affected by intense ungulate browsing as well as climate warming. In sum, total species richness was maximized in large and tall willow patches of small to intermediate degree of fragmentation. These community effects were mainly driven by responses in the occupancy rates of species depending on tall willows for foraging and breeding, while species favouring other vegetation states were not affected. In light of the predicted climate driven willow shrub encroachment in riparian tundra habitats, our study predicts that many bird species would increase in abundance, and that the bird community as a whole could become enriched. Conversely, in tundra regions where overabundance of large herbivores leads to decreased areal extent, reduced height and increased fragmentation

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

    OpenAIRE

    Ulsig, Laura; Nichol, Caroline J.; Huemmrich, Karl F.; Landis, David R.; Middleton, Elizabeth M.; Lyapustin, Alexei I.; Mammarella, Ivan; Levula, Janne; Porcar-Castell, Albert

    2017-01-01

    Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI). This study investigates the potential of a Photochemical Reflectance Index (PRI), which has been linked to vegetation light use efficiency, to improve the accuracy of MO...

  18. Detecting inter-annual variations in the phenology of evergreen conifers using long-term MODIS vegetation index time series.

    OpenAIRE

    Ulsig, Laura

    2016-01-01

    Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalised Difference Vegetation Index (NDVI). This study investigates the potential of the Photochemical Reflectance Index (PRI), which has been linked to vegetation light use efficiency, to improve the accuracy of ...

  19. Variation in soil enzyme activity as a function of vegetation amount, type, and spatial structure in fire-prone Mediterranean shrublands.

    Science.gov (United States)

    Mayor, Ángeles G; Goirán, Silvana B; Vallejo, V Ramón; Bautista, Susana

    2016-12-15

    Fire-prone Mediterranean shrublands may be seriously threatened by land degradation due to progressive opening of the vegetation cover driven by increasing drought and fire recurrence. However, information about the consequences of this opening process for critical ecosystem functions is scant. In this work, we studied the influence of vegetation amount, type, and spatial pattern in the variation of extracellular soil enzyme activity (acid phosphatase, β-glucosidase, and urease) in fire-prone shrublands in eastern Spain. Soil was sampled in vegetation-patch and open-interpatch microsites in 15 shrubland sites affected by large wildfires in 1991. On average, the activities of the three enzymes were 1.5 (β-glucosidase and urease) to 1.7 (acid phosphatase) times higher in soils under vegetation patches than in adjacent interpatches. In addition, phosphatase activity for both microsites significantly decreased with the fragmentation of the vegetation. This result was attributed to a lower influence of roots -the main source of acid phosphatase- in the bigger interpatches of the sites with lower patch cover, and to feedbacks between vegetation pattern, redistribution of resources, and soil quality during post-fire vegetation dynamics. Phosphatase activity was also 1.2 times higher in patches of resprouter plants than in patches of non-resprouters, probably due to the faster post-fire recovery and older age of resprouter patches in these fire-prone ecosystems. The influence on the studied enzymes of topographic and climatic factors acting at the landscape scale was insignificant. According to our results, variations in the cover, pattern, and composition of vegetation patches may have profound impacts on soil enzyme activity and associated nutrient cycling processes in fire-prone Mediterranean shrublands, particularly in those related to phosphorus. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. [Variations of structure and of flora of the "carrasco" vegetation of the Ibiapaba plateau, state of Cearsá, Brazil].

    Science.gov (United States)

    de Araújo, F S; Martins, F R; Shepherd, G J

    1999-11-01

    "Carrasco" is a closed, tall-shrubby, xerophilous vegetation on Quartz Sand soils between altitudes of 700 and 900 m on Ibiapaba and Araripe plateaus in the Brazilian semi-arid domain. As it is still very poorly known, this paper aims to describe the structure and composition of the woody community and its spatial variation in relation to the soil. One-hundred 10 x 10 m plots were located by pairs of random numbers in a coordinate system at the locality of Jaburuna (3 degrees 54'34"S, 40 degrees 59'24"W, about 830 m altitude), municipality of Ubajara, north Ibiapaba. All woody plants with a minimum stem diameter of 3 cm at ground level had their vertical height (not for climbers) and stem perimeter recorded. A soil extract from 0-50 cm depth was taken at the centre of each plot. Published surveys of other carrasco areas on the south Ibiapaba were considered for comparison. The community structure showed great dominance concentration, the most abundant species (Acacia langsdorffii, Piptadenia moniliformis, Thiloa glaucocarpa) varied between surveys. At Jaburuna 81% of all sampled plants were shrubs, 14% trees (the most with less than 10 cm of trunk diameter and 6 m height), and 5% climbers. Canberra distances and Jaccard's Indices were calculated from a primary matrix of 87 species (with 5 or more individuals) and 175 plots. Several methods of cluster analysis were employed, all showed great floristic variation from place to place. A matrix of soil physical and chemical variates per plot was constructed, and the canonical correspondence analysis was applied to both primary and soil matrices. Lower pH and higher sum of bases (e. g. Brunfelsia cuneifolia, Neojeobertia candoleana), higher content of gross sand (e. g. Acacia glomerosa, Aspidosperma subincanumn) and higher content of fine sand (e. g. Aspidosperma discolor, Hymenaea velutina) were the main variates separating species. The floristic richness at Jaburuna was of 74 species, and the surveys showed no

  1. Spider Trait Assembly Patterns and Resilience under Fire-Induced Vegetation Change in South Brazilian Grasslands

    Science.gov (United States)

    Podgaiski, Luciana R.; Joner, Fernando; Lavorel, Sandra; Moretti, Marco; Ibanez, Sebastien; Mendonça, Milton de S.; Pillar, Valério D.

    2013-01-01

    Disturbances induce changes on habitat proprieties that may filter organism's functional traits thereby shaping the structure and interactions of many trophic levels. We tested if communities of predators with foraging traits dependent on habitat structure respond to environmental change through cascades affecting the functional traits of plants. We monitored the response of spider and plant communities to fire in South Brazilian Grasslands using pairs of burned and unburned plots. Spiders were determined to the family level and described in feeding behavioral and morphological traits measured on each individual. Life form and morphological traits were recorded for plant species. One month after fire the abundance of vegetation hunters and the mean size of the chelicera increased due to the presence of suitable feeding sites in the regrowing vegetation, but irregular web builders decreased due to the absence of microhabitats and dense foliage into which they build their webs. Six months after fire rosette-form plants with broader leaves increased, creating a favourable habitat for orb web builders which became more abundant, while graminoids and tall plants were reduced, resulting in a decrease of proper shelters and microclimate in soil surface to ground hunters which became less abundant. Hence, fire triggered changes in vegetation structure that lead both to trait-convergence and trait-divergence assembly patterns of spiders along gradients of plant biomass and functional diversity. Spider individuals occurring in more functionally diverse plant communities were more diverse in their traits probably because increased possibility of resource exploitation, following the habitat heterogeneity hypothesis. Finally, as an indication of resilience, after twelve months spider communities did not differ from those of unburned plots. Our findings show that functional traits provide a mechanistic understanding of the response of communities to environmental change

  2. Genotypic variations in the accumulation of Cd, Cu, Pb and Zn exhibited by six commonly grown vegetables

    International Nuclear Information System (INIS)

    Alexander, P.D.; Alloway, B.J.; Dourado, A.M.

    2006-01-01

    Metal contaminants in garden and allotment soils could possibly affect human health through a variety of pathways. This study focused on the potential pathway of consumption of vegetables grown on contaminated soil. Five cultivars each of six common vegetables were grown in a control and in a soil spiked with Cd, Cu, Pb and Zn. Highly significant differences in metal content were evident between cultivars of a number of vegetables for several of the contaminants. Carrot and pea cultivars exhibited significant differences in accumulated concentrations of Cd and Cu with carrot cultivars also exhibiting significant differences in Zn. Distinctive differences were also identified when comparing one vegetable to another, legumes (Leguminosae) tending to be low accumulators, root vegetables (Umbelliferae and Liliaceae) tending to be moderate accumulators and leafy vegetables (Compositae and Chenopodiaceae) being high accumulators. - Genotypic differences between cultivars of vegetable species can be important in determining the extent of accumulation of metals from contaminated soil

  3. Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.

    Science.gov (United States)

    Wan, Long; Tong, Jing; Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

    2016-01-01

    Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

  4. Detection of heavy metal Cd in polluted fresh leafy vegetables by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Yao, Mingyin; Yang, Hui; Huang, Lin; Chen, Tianbing; Rao, Gangfu; Liu, Muhua

    2017-05-10

    In seeking a novel method with the ability of green analysis in monitoring toxic heavy metals residue in fresh leafy vegetables, laser-induced breakdown spectroscopy (LIBS) was applied to prove its capability in performing this work. The spectra of fresh vegetable samples polluted in the lab were collected by optimized LIBS experimental setup, and the reference concentrations of cadmium (Cd) from samples were obtained by conventional atomic absorption spectroscopy after wet digestion. The direct calibration employing intensity of single Cd line and Cd concentration exposed the weakness of this calibration method. Furthermore, the accuracy of linear calibration can be improved a little by triple Cd lines as characteristic variables, especially after the spectra were pretreated. However, it is not enough in predicting Cd in samples. Therefore, partial least-squares regression (PLSR) was utilized to enhance the robustness of quantitative analysis. The results of the PLSR model showed that the prediction accuracy of the Cd target can meet the requirement of determination in food safety. This investigation presented that LIBS is a promising and emerging method in analyzing toxic compositions in agricultural products, especially combined with suitable chemometrics.

  5. Moisture variation inferred from a nebkha profile correlates with vegetation changes in the southwestern Mu Us Desert of China over one century.

    Science.gov (United States)

    Li, Jinchang; Zhao, Yanfang; Han, Liuyan; Zhang, Guoming; Liu, Rentao

    2017-11-15

    We inferred moisture variations from the early 1930s to the early 2010s in the southwestern Mu Us Desert of China using Rb/Sr ratio, chemical index of alteration (CIA), and organic matter (OM) content in a nebkha profile. Our results showed that the variations in moisture may have been the main factor that controlled vegetation recovery or degradation, and we believe that gradual vegetation recovery was notable throughout the study area during the past 80years, despite two notable degradation stages during the mid-1950s and the mid-1980s. The Rb/Sr ratio, CIA, and OM content revealed that moisture levels increased during the study period, though with large interannual variations. During the early stage of nebkha formation, the moisture variations were controlled by unusually low precipitation. Thereafter, the precipitation, pan evaporation and temperature determined together moisture variations, but the key factor determining moisture variations was different during different periods. The moisture variations trend revealed in this study may not be restricted to this region as it was similar with the adjacent Mongolian Plateau. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Examining Severe Drought-Induced Vegetation Change and its Influence on Water Resources

    Science.gov (United States)

    White, A. B.; Springer, E. P.; Vivoni, E. R.

    2007-12-01

    A "global-change-type" drought that occurred in the southwestern U.S. from 2000 to 2003, accompanied by increased temperatures and bark beetle infestations, induced large-scale woodland overstory mortality, the consequent redistribution of water, radiation, and nutrients, as well as modification of the ecosystem phenology. Our objectives in this research are to examine these vegetation changes in detail and to determine whether they translated to changes in hydrological processes. We chose the Rio Ojo Caliente, a subbasin of the Rio Grande, as a study site since a significant portion of the woodland ecosystem (piñon-juniper) was affected. Examining a remotely-sensed vegetation index (1-km AVHRR NDVI from 1989 to 2006), there is an increasing trend in the mean NDVI from 1989 to 1998 (pre-drought period), a decreasing trend from 1999 to 2003 (drought period), and a dramatic increasing trend from 2004 to 2006 (post-drought period) in which the mean NDVI rebounds to pre- drought magnitudes. Streamflow records from 1932 to 2006 show the watershed to be primarily spring snowmelt-driven, although monsoonal summer precipitation also plays a significant role. We compare the temporal variability in the streamflow to the NDVI, including the mean, anomalies from the mean, and seasonally- based duration curves, and find significant correlations (correlation coefficient ρ = -0.61) between the streamflow and NDVI at approximately a three-month lag (NDVI lagging streamflow). In analyzing the three phases of the drought, the correlation is slightly stronger during the pre-drought (ρ = -0.64) and drought (ρ = -0.65) periods, yet markedly stronger during the post-drought period (ρ = -0.74). This suggests that the coupling between vegetation water use and streamflow is tighter after the drought. This may be attributable to the reduction in the less-responsive overstory (pinñon mortality) and increase in the more-responsive understory (grasses and shrubs exploiting newly

  7. Space-resolved analysis of trace elements in fresh vegetables using ultraviolet nanosecond laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Juve, Vincent; Portelli, Richard; Boueri, Myriam; Baudelet, Matthieu; Yu Jin

    2008-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to analyze trace elements contained in fresh vegetables. A quadrupled Nd:YAG laser is used in the experiments for ablation. Analyzed samples come from local markets and represent frequently consumed vegetables. For a typical root vegetable, such as potato, spectral analysis of the plasma emission reveals more than 400 lines emitted by 27 elements and 2 molecules, C 2 and CN. Among these species, one can find trace as well as ultra-trace elements. A space-resolved analysis of several trace elements with strong emissions is then applied to typical root, stem and fruit vegetables. The results from this study demonstrate the potential of an interesting tool for botanical and agricultural studies as well for food quality/safety and environment pollution assessment and control

  8. Seasonal variations of seismicity and geodetic strain in the Himalaya induced by surface hydrology

    OpenAIRE

    Bettinelli, Pierre; Avouac, Jean-Philippe; Flouzat, Mireille; Bollinger, Laurent; Ramillien, Guillaume; Rajaure, Sudhir; Sapkota, Som

    2008-01-01

    One way to probe earthquake nucleation processes and the relation between stress buildup and seismicity is to analyze the sensitivity of seismicity to stress perturbations. Here, we report evidence for seasonal strain and stress (~ 2–4 kPa) variations in the Nepal Himalaya, induced by water storage variations which correlate with seasonal variations of seismicity. The seismicity rate is twice as high in the winter as in the summer, and correlates with stress rate variations. We infer ~ 10–20 ...

  9. RAPD analysis of colchicine induced variation of the Dendrobium ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... species of the Dendrobium genera, and 13 orchids across generas. ... to detect variations at species level and among somaclonal variants in this study. ..... alternative for colchicines in in vitro choromosome doubling of Lilium.

  10. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Tagesson, Torbern (Dept. of Physical Geography and Ecosystem Analysis, Lund Univ., Lund (SE))

    2007-11-15

    Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1

  11. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden

    International Nuclear Information System (INIS)

    Tagesson, Torbern

    2007-11-01

    Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1

  12. Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

    NARCIS (Netherlands)

    Dupont, L.M.; Caley, T.; Kim, J.H.; Castañeda, I.S; Malaize, B.; Giraudeau, J.

    2011-01-01

    Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a

  13. Spatial and temporal variation In streamside herbaceous vegetation of the Upper Verde River: 1996-2001 [Chapter 7

    Science.gov (United States)

    Alvin L. Medina; Jonathan W. Long

    2012-01-01

    Streamside environments are inherently dynamic, yet streamside vegetation plays a key stabilizing role on riparian and aquatic habitats (Van Devender and Spaulding 1979; Van Devender and others 1987). Because of its dynamism, streamside vegetation is rarely the subject of classification analyses, yet it is a focal point for land managers regulating land uses, such as...

  14. Vegetation induced diel signal and its meaning in recharge and discharge regions

    Science.gov (United States)

    Gribovszki, Zoltán; Tóth, Tibor; Csáfordi, Péter; Szabó, András; Móricz, Norbert; Kalicz, Péter

    2017-04-01

    Afforestation, promoted by the European Union is planned in Hungary in the next decades. One of the most important region for afforestation is the Hungarian Great Plain where the precipitation is far below potential ET so forests can not survive without significant water uptake from shallow groundwater. Diel fluctuations of hydrological variables (e.g., soil moisture, shallow groundwater level, streamflow rate) are rarely investigated in the hydrologic literature although these short-term fluctuations may incorporate useful information (like groundwater uptake) about hydro-ecological systems in shallow groundwater areas. Vegetation induced diel fluctuations are rarely compared under varying hydrologic conditions (such as recharge and discharge zones). In this study, the data of soil moisture and shallow groundwater monitoring under different surface covers (forest and neighboring agricultural plots) in discharge and recharge regions were analyzed to gain a better understanding of the vegetation hydrological impact or water uptake in changing climate. The pilot areas of the study are located in Hungarian Great Plain and in Western Hungary. The water table under the forest displayed a typical night-time recovery in the discharge region, indicating a significant groundwater supply. Certainly, the root system of the forest was able to tap the groundwater in depths measuring a few metres, while the shallower roots of the herbaceous vegetation generally did not reach the groundwater reservoir at these depths. In the recharge zone the water table under the forest showed step-like diel pattern that refer to a lack of additional groundwater supply from below. The low groundwater evapotranspiration of the forest in the recharge zone was due to the lack of the groundwater supply in the recharge area. Similar patterns can be detected in the soil moisture of recharge and discharge zones as well. Our results suggest that local estimations of groundwater evapotranspiration from

  15. Mapping and exploring variation in post-fire vegetation recovery following mixed severity wildfire using airborne LiDAR.

    Science.gov (United States)

    Gordon, Christopher E; Price, Owen F; Tasker, Elizabeth M

    2017-07-01

    There is a public perception that large high-severity wildfires decrease biodiversity and increase fire hazard by homogenizing vegetation composition and increasing the cover of mid-story vegetation. But a growing literature suggests that vegetation responses are nuanced. LiDAR technology provides a promising remote sensing tool to test hypotheses about post-fire vegetation regrowth because vegetation cover can be quantified within different height strata at fine scales over large areas. We assess the usefulness of airborne LiDAR data for measuring post-fire mid-story vegetation regrowth over a range of spatial resolutions (10 × 10 m, 30 × 30 m, 50 × 50 m, 100 × 100 m cell size) and investigate the effect of fire severity on regrowth amount and spatial pattern following a mixed severity wildfire in Warrumbungle National Park, Australia. We predicted that recovery would be more vigorous in areas of high fire severity, because park managers observed dense post-fire regrowth in these areas. Moderate to strong positive associations were observed between LiDAR and field surveys of mid-story vegetation cover between 0.5-3.0 m. Thus our LiDAR survey was an apt representation of on-ground vegetation cover. LiDAR-derived mid-story vegetation cover was 22-40% lower in areas of low and moderate than high fire severity. Linear mixed-effects models showed that fire severity was among the strongest biophysical predictors of mid-story vegetation cover irrespective of spatial resolution. However much of the variance associated with these models was unexplained, presumably because soil seed banks varied at finer scales than our LiDAR maps. Dense patches of mid-story vegetation regrowth were small (median size 0.01 ha) and evenly distributed between areas of low, moderate and high fire severity, demonstrating that high-severity fires do not homogenize vegetation cover. Our results are relevant for ecosystem conservation and fire management because they: indicate

  16. Assessment of the TNT- and AMPA-Induced Changes in Vegetation Morphology and Bio-physical Properties

    Science.gov (United States)

    Campbell, P. K.; Middleton, E.; Corp, L.

    2009-12-01

    Currently, there is no satisfactory method for locating unexploded ordinance or to mitigate the environmental impacts of leaked TNT. Non-exploded TNT-containing land mines deployed during military training exercises eventually leak TNT into the soils, where it is partially degraded into nitrate and toluene, a carcinogen. Environmental stresses alter plant physiology, affecting photosynthesis as well as the production of protective chemicals such as phenolic compounds which fluoresce in the blue/green spectrum. Changes in the fluorescence and reflectance spectral signatures of vegetation occur concurrently with the changes in plant vigor and chemical constituents. Thus, monitoring of vegetation vigor based on fluorescence and reflectance measurements could provide the means for detecting contamination from trinitrotoluene (TNT), a common compound contained in land mines. The goal of this study was to evaluate the capability of fluorescence sensing systems to remotely detect the presence of TNT-related compounds sequestered in vegetation growing on TNT contaminated soils. Using instrumentation and methodologies that utilize reflectance and actively induced fluorescence associated with “stead-state” emissions, we conducted experiments on four experimental species - two of which have the C4 photosynthetic pathway and two of which have the more common C3 pathway. The experimental plants were grown outdoors in 2 gallon pots in a 75:25 mixture of white quartz sand and perlite, with planted pots placed in larger pots to retain water and TNT solution added. Plants were randomly assigned to treatments for twice weekly applications of 0, 10, and 20 μl/l TNT solutions [doses ~30 μl/l are toxic] and watered daily as necessary. Our findings, using ChlF spectra, indicate statistically significant differences between TNT treated and control samples in the blue and green regions. Maximum treatment separation was achieved using 280Ex and measuring emissions in the blue

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

    Science.gov (United States)

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

    2014-05-01

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

  18. CO2 leakage-induced vegetation decline is primarily driven by decreased soil O2.

    Science.gov (United States)

    Zhang, Xueyan; Ma, Xin; Zhao, Zhi; Wu, Yang; Li, Yue

    2016-04-15

    To assess the potential risks of carbon capture and storage (CCS), studies have focused on vegetation decline caused by leaking CO2. Excess soil CO2 caused by leakage can affect soil O2 concentrations and soil pH, but how these two factors affect plant development remains poorly understood. This hinders the selection of appropriate species to mitigate potential negative consequences of CCS. Through pot experiments, we simulated CO2 leakage to examine its effects on soil pH and soil O2 concentrations. We subsequently assessed how maize growth responded to these changes in soil pH and O2. Decreased soil O2 concentrations significantly reduced maize biomass, and explained 69% of the biomass variation under CO2 leakage conditions. In contrast, although leaked CO2 changed soil pH significantly (from 7.32 to 6.75), it remained within the optimum soil pH range for maize growth. This suggests that soil O2 concentration, not soil pH, influences plant growth in these conditions. Therefore, in case of potential CO2 leakage risks, hypoxia-tolerant species should be chosen to improve plant survival, growth, and yield. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Climate change-induced vegetation shifts lead to more ecological droughts despite projected rainfall increases in many global temperate drylands.

    Science.gov (United States)

    Tietjen, Britta; Schlaepfer, Daniel R; Bradford, John B; Lauenroth, William K; Hall, Sonia A; Duniway, Michael C; Hochstrasser, Tamara; Jia, Gensuo; Munson, Seth M; Pyke, David A; Wilson, Scott D

    2017-07-01

    Drylands occur worldwide and are particularly vulnerable to climate change because dryland ecosystems depend directly on soil water availability that may become increasingly limited as temperatures rise. Climate change will both directly impact soil water availability and change plant biomass, with resulting indirect feedbacks on soil moisture. Thus, the net impact of direct and indirect climate change effects on soil moisture requires better understanding. We used the ecohydrological simulation model SOILWAT at sites from temperate dryland ecosystems around the globe to disentangle the contributions of direct climate change effects and of additional indirect, climate change-induced changes in vegetation on soil water availability. We simulated current and future climate conditions projected by 16 GCMs under RCP 4.5 and RCP 8.5 for the end of the century. We determined shifts in water availability due to climate change alone and due to combined changes of climate and the growth form and biomass of vegetation. Vegetation change will mostly exacerbate low soil water availability in regions already expected to suffer from negative direct impacts of climate change (with the two RCP scenarios giving us qualitatively similar effects). By contrast, in regions that will likely experience increased water availability due to climate change alone, vegetation changes will counteract these increases due to increased water losses by interception. In only a small minority of locations, climate change-induced vegetation changes may lead to a net increase in water availability. These results suggest that changes in vegetation in response to climate change may exacerbate drought conditions and may dampen the effects of increased precipitation, that is, leading to more ecological droughts despite higher precipitation in some regions. Our results underscore the value of considering indirect effects of climate change on vegetation when assessing future soil moisture conditions in water

  20. Climate change-induced vegetation shifts lead to more ecological droughts despite projected rainfall increases in many global temperate drylands

    Science.gov (United States)

    Tietjen, Britta; Schlaepfer, Daniel R.; Bradford, John B.; Laurenroth, William K.; Hall, Sonia A.; Duniway, Michael C.; Hochstrasser, Tamara; Jia, Gensuo; Munson, Seth M.; Pyke, David A.; Wilson, Scott D.

    2017-01-01

    Drylands occur world-wide and are particularly vulnerable to climate change since dryland ecosystems depend directly on soil water availability that may become increasingly limited as temperatures rise. Climate change will both directly impact soil water availability, and also change plant biomass, with resulting indirect feedbacks on soil moisture. Thus, the net impact of direct and indirect climate change effects on soil moisture requires better understanding.We used the ecohydrological simulation model SOILWAT at sites from temperate dryland ecosystems around the globe to disentangle the contributions of direct climate change effects and of additional indirect, climate change-induced changes in vegetation on soil water availability. We simulated current and future climate conditions projected by 16 GCMs under RCP 4.5 and RCP 8.5 for the end of the century. We determined shifts in water availability due to climate change alone and due to combined changes of climate and the growth form and biomass of vegetation.Vegetation change will mostly exacerbate low soil water availability in regions already expected to suffer from negative direct impacts of climate change (with the two RCP scenarios giving us qualitatively similar effects). By contrast, in regions that will likely experience increased water availability due to climate change alone, vegetation changes will counteract these increases due to increased water losses by interception. In only a small minority of locations, climate change induced vegetation changes may lead to a net increase in water availability. These results suggest that changes in vegetation in response to climate change may exacerbate drought conditions and may dampen the effects of increased precipitation, i.e. leading to more ecological droughts despite higher precipitation in some regions. Our results underscore the value of considering indirect effects of climate change on vegetation when assessing future soil moisture conditions in water

  1. Large-Scale Variation in Forest Carbon Turnover Rate and its Relation to Climate - Remote Sensing vs. Global Vegetation Models

    Science.gov (United States)

    Carvalhais, N.; Thurner, M.; Beer, C.; Forkel, M.; Rademacher, T. T.; Santoro, M.; Tum, M.; Schmullius, C.

    2015-12-01

    While vegetation productivity is known to be strongly correlated to climate, there is a need for an improved understanding of the underlying processes of vegetation carbon turnover and their importance at a global scale. This shortcoming has been due to the lack of spatially extensive information on vegetation carbon stocks, which we recently have been able to overcome by a biomass dataset covering northern boreal and temperate forests originating from radar remote sensing. Based on state-of-the-art products on biomass and NPP, we are for the first time able to study the relation between carbon turnover rate and a set of climate indices in northern boreal and temperate forests. The implementation of climate-related mortality processes, for instance drought, fire, frost or insect effects, is often lacking or insufficient in current global vegetation models. In contrast to our observation-based findings, investigated models from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT, are able to reproduce spatial climate - turnover rate relationships only to a limited extent. While most of the models compare relatively well to observation-based NPP, simulated vegetation carbon stocks are severely biased compared to our biomass dataset. Current limitations lead to considerable uncertainties in the estimated vegetation carbon turnover, contributing substantially to the forest feedback to climate change. Our results are the basis for improving mortality concepts in global vegetation models and estimating their impact on the land carbon balance.

  2. Do variations in the composition and structure of vegetation allow floristic groups to be detected in a subtropical moist forest in southern Brazil?

    Directory of Open Access Journals (Sweden)

    João Paulo de Maçaneiro

    2016-12-01

    Full Text Available Variations in vegetation based on topographic location have become an interest of researchers. However, few studies have verified floristic associations related to the topographic position of a slope. In this work, we analyzed if variations in vegetation allow floristic groups to be detected in a subtropical moist forest. The vegetation was sampled in 25 plots of 400 m² distributed systematically, where individuals with a DBH ≥ 5.0 cm were measured. We sampled 1,727 individuals and 144 species. The NMDS ordination segregated three groups based on the topographic position of the slope (Monte Carlo, P ≥ 0.05; ANOSIM, P < 0.001. Euterpe edulis and Sloanea guianensis were notable in the lower and middle sections of the slope, whereas Ocotea aciphylla and Alchornea triplinervia were notable in the upper section. Some species were indicators of the analyzed sectors, such as Actinostemon concolor and Alsophila setosa in the lower section, Cyathea corcovadensis and Rudgea recurva in the middle section, and Myrcia pulchra and Podocarpus sellowii in the upper section. Our results indicate that the floristic and structural variations observed by Veloso and Klein (1959 and Klein (1980; 1984 for Vale do Itajaí in Santa Catarina are statistically valid today, because we verified the formation of different groups according to the topographic position of the slope.

  3. Variations of helicon wave induced radial plasma transport in different experimental conditions

    International Nuclear Information System (INIS)

    Petrzilka, V.

    1993-08-01

    Variations of the helicon wave induced radial plasma transport are presented in dependence on values of the plasma radius, magnetostatic field, plasma density, frequency of the helicon wave and on the ion charge. 22 refs., 14 figs

  4. Influence of the height of the vegetation cover in the variation of the kinetic energy of raindrops intercepted; Influencia de la altura de la cubierta vegetal en la variacion de la energia cinetica de las gotas de lluvia interceptadas

    Energy Technology Data Exchange (ETDEWEB)

    Roldan Soriano, M.

    2009-07-01

    The erosive capacity of raindrops is function of mass (size) and terminal velocity. Drop mass and velocity govern the inherent erosivity of rainfall through kinetic energy. Kinetic energy is a very important property of the rainfall because it is one of the sources of energy in the process of water erosion. Vegetative canopy intercepts the raindrops and causes a variation on this rainfall kinetic energy due to modification of diameters and velocities distributions. If the height of canopy is enough, the bigger intercepted drops could achieve high velocities and their kinetic energies can increases. In this paper a quantitative evaluation of the increase of kinetic energy of intercepted drops is obtained and it is showed that this kinetic energy increases exponentially with vegetation height. (Author) 9 refs.

  5. Induced genetic variation for aluminum and salt tolerance in rice

    International Nuclear Information System (INIS)

    Chaudhry, M.A.; Yoshida, S.; Vegara, B.S.

    1989-01-01

    Full text: MNH applied to fertilized egg cells of 'Taichung 65' led to an increase in genetic variation in the progenies. Of a M 2 population of 15,000 seedlings, 2.3% were scored tolerant to salt. Tolerant plants showed less shoot and root growth inhibition. 50 variants expressed different degrees of tolerance to Al, even up to 30 ppm. The tolerance was related to longer root development. (author)

  6. Human-Induced Climate Variations Linked to Urbanization: From Observations to Modeling

    Science.gov (United States)

    Shepherd, J. Marshall; Jin, Menglin

    2004-01-01

    The goal of this session is to bring together scientists from interdisciplinary backgrounds to discuss the data, scientific approaches and recent results focusing on the impact of urbanization on the climate. The discussion will highlight current observational and modeling capabilities being employed for investigating the urban environment and its linkage to the change in the Earth's climate system. The goal of the session is to identify our current stand and the future direction on the topic. Urbanization is one of the extreme cases of land use change. Most of population of the world has moved to urban areas. By 1995, more than 70% of population of North America and Europe were living in cities. By 2025, the United Nations estimates that 60% of the worlds population will live in cities. Although currently only 1.2% of the land is urban, better understanding of how the atmosphere-ocean-land-biosphere components interact as a coupled system and the influence of human activities on this system is critical. Our understanding of urbanization effect is incomplete, partly because human activities induce new changes on climate in addition to the original natural variations, and partly because previously few data available for study urban effect globally. Urban construction changes surface roughness, albedo, heat capacity and vegetation coverage. Traffic and industry increase atmospheric aerosol. It is suggested that urbanization may modify rainfall processes through aerosol-cloud interactions or dynamic feedbacks. Because urbanization effect on climate is determined by many factors including land cover, the city's microscale features, population density, and human lifestyle patterns, it is necessary to study urban areas over globe.

  7. Reduction of coating induced polarization aberrations by controlling the polarization state variation

    International Nuclear Information System (INIS)

    Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

    2011-01-01

    The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

  8. Induced quantitative variation in wild and cultivated urd and mungbean

    International Nuclear Information System (INIS)

    Ignacimuthu, S.; Babu, C.R.

    1993-01-01

    Seeds of wild and cultivated urd and mung beans were subjected to mutagenesis and some quantitative characters were analysed in the M 2 generation for the range of variability and its significance. Components of variability, heritability, and genetic advance were also estimated. The results indicate that induced mutations are random, polydirectional and quantitative in nature. They also bring about heritable changes in polygenic system. From the patterns of induced variability, it is clear that the threshold action of certain proportion of mutant loci is the basis for phenotypic modification. (author). 24 refs., 2 tabs

  9. Seasonal Variation in the Occurrence of Pregnancy-Induced ...

    African Journals Online (AJOL)

    Pregnancy-Induced Hypertension (PIH) is one of the leading causes of maternal, neonatal and infant mortality. Several studies have suggested that the occurrence of PIH may be dependent on environmental factors. Although, several countries have documented the prevalence of PIH, little is known about the occurrence ...

  10. Analysis of genetic variation of inducible nitric oxide synthase and ...

    African Journals Online (AJOL)

    The genetic diversity of 100 Malaysian native chickens was investigated using polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) for two candidate genes: inducible nitric oxide synthase (INOS) and natural resistance-associated macrophage protein 1 (NRAMP1). The two genes were selected ...

  11. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    Science.gov (United States)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  12. 15. Sensitivity in visualizing vegetations in cardiac lead-induced endocarditis: A comparative study between transesophageal vs. transthoracic echocardiography

    Directory of Open Access Journals (Sweden)

    A. AlFagih

    2016-07-01

    Full Text Available Despite advancement in sterile cardiac device implantation techniques, wound infections and/or bacteremia remain a significant problem. The presence of a vegetation in lead-induced endocarditis (LIE is a critical factor that determines the management. Transthoracic (TTE and Transesophageal (TEE Echocardiography are two different cardiac modalities that are used for the detection of lead vegetation. However, it is not yet clear which of the two has the highest diagnostic accuracy. We aim to identify which of the two has the highest sensitivity. In addition, we aim to correlate the existence of a vegetation with blood and wound culture results. We conducted a chart review in 113 patients whom underwent lead extraction at Prince Sultan Cardiac Center in Saudi Arabia during the period of Jan, 2002 to Jul, 2015. Six patients underwent lead extraction twice, increasing the number to be a total of 119 cases. Out of the study cohort, we include 38 patients who had both TTE and TEE done prior to lead extraction. Data regarding TTE, TEE, as well as blood and wound cultures were collected from echocardiography and microbiology lab reports using a well-structured case report form.Of the study population, 21 patients (55.3% had lead vegetations visualized either by TTE or TEE. Nineteen patients had vegetations detected by TEE, compared to 6 patients only when TTE was used. The sensitivity of TEE and TTE were 90.5% (CI: 69.6–98.8% and 28.5% (95% CI: 11.3–52.1%, respectively. Blood and wound culture results showed that in the presence of a vegetation, blood cultures were positive in 55% of the cases (P = 0.036 while only 44.4% of those with vegetations had a positive wound culture (P = 0.347. TEE has higher sensitivity in detecting vegetations compared to TTE in LIE. The presence of a vegetation is more likely to be associated with a positive blood culture than a positive wound culture. Further studies ought to measure the accuracy of different

  13. The AMMA-CATCH Gourma observatory site in Mali: Relating climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources

    Science.gov (United States)

    Mougin, E.; Hiernaux, P.; Kergoat, L.; Grippa, M.; de Rosnay, P.; Timouk, F.; Le Dantec, V.; Demarez, V.; Lavenu, F.; Arjounin, M.; Lebel, T.; Soumaguel, N.; Ceschia, E.; Mougenot, B.; Baup, F.; Frappart, F.; Frison, P. L.; Gardelle, J.; Gruhier, C.; Jarlan, L.; Mangiarotti, S.; Sanou, B.; Tracol, Y.; Guichard, F.; Trichon, V.; Diarra, L.; Soumaré, A.; Koité, M.; Dembélé, F.; Lloyd, C.; Hanan, N. P.; Damesin, C.; Delon, C.; Serça, D.; Galy-Lacaux, C.; Seghieri, J.; Becerra, S.; Dia, H.; Gangneron, F.; Mazzega, P.

    2009-08-01

    SummaryThe Gourma site in Mali is one of the three instrumented meso-scale sites deployed in West-Africa as part of the African Monsoon Multi-disciplinary Analysis (AMMA) project. Located both in the Sahelian zone sensu stricto, and in the Saharo-Sahelian transition zone, the Gourma meso-scale window is the northernmost site of the AMMA-CATCH observatory reached by the West African Monsoon. The experimental strategy includes deployment of a variety of instruments, from local to meso-scale, dedicated to monitoring and documentation of the major variables characterizing the climate forcing, and the spatio-temporal variability of surface processes and state variables such as vegetation mass, leaf area index (LAI), soil moisture and surface fluxes. This paper describes the Gourma site, its associated instrumental network and the research activities that have been carried out since 1984. In the AMMA project, emphasis is put on the relations between climate, vegetation and surface fluxes. However, the Gourma site is also important for development and validation of satellite products, mainly due to the existence of large and relatively homogeneous surfaces. The social dimension of the water resource uses and governance is also briefly analyzed, relying on field enquiry and interviews. The climate of the Gourma region is semi-arid, daytime air temperatures are always high and annual rainfall amounts exhibit strong inter-annual and seasonal variations. Measurements sites organized along a north-south transect reveal sharp gradients in surface albedo, net radiation, vegetation production, and distribution of plant functional types. However, at any point along the gradient, surface energy budget, soil moisture and vegetation growth contrast between two main types of soil surfaces and hydrologic systems. On the one hand, sandy soils with high water infiltration rates and limited run-off support almost continuous herbaceous vegetation with scattered woody plants. On the other

  14. A Mechanistic Perspective on Process-Induced Changes in Glucosinolate Content in Brassica Vegetables: A Review

    NARCIS (Netherlands)

    Nugrahedi, P.Y.; Verkerk, R.; Widianarko, B.; Dekker, M.

    2015-01-01

    Brassica vegetables are consumed mostly after processing, which is expected to give beneficial effects on the vegetable properties, such as improved palatability and bioavailability of nutrients, or shelf life extension. But processing also results to various changes in the content of health

  15. Spatial Variations of Heavy Metals in the Soils of Vegetable-Growing Land along Urban-Rural Gradient of Nanjing, China

    Science.gov (United States)

    Fang, Shi-Bo; Hu, Hao; Sun, Wan-Chun; Pan, Jian-Jun

    2011-01-01

    China has experienced rapid urbanization in recent years. The acceleration of urbanization has created wealth and opportunity as well as intensified ecological and environmental problems, especially soil pollution. Our study concentrated on the variation of heavy metal content due to urbanization in the vegetable-growing soil. Laws and other causes of the spatial-temporal variation in heavy metal content of vegetable-growing soils were analyzed for the period of urbanization in Nanjing (the capital of Jiangsu province in China). The levels of Cu, Zn, Pb, Cd and Hg in samples of vegetable-growing soil were detected. The transverse, vertical spatio-temporal variation of heavy metals in soil was analyzed on the base of field investigations and laboratory analysis. The results show that: (1) in soil used for vegetable production, the levels of heavy metals decreased gradually from urban to rural areas; the levels of the main heavy metals in urban areas are significantly higher than suburban and rural areas; (2) the means of the levels of heavy metals, calculated by subtracting the sublayer (15–30 cm) from the toplayer (0–15 cm), are all above zero and large in absolute value in urban areas, but in suburban and rural areas, the means are all above or below zero and small in absolute value. The causes of spatial and temporal variation were analyzed as follows: one cause was associated with mellowness of the soil and the length of time the soil had been used for vegetable production; the other cause was associated with population density and industrial intensity decreasing along the urban to rural gradient (i.e., urbanization levels can explain the distribution of heavy metals in soil to some extent). Land uses should be planned on the basis of heavy metal pollution in soil, especially in urban and suburban regions. Heavily polluted soils have to be expected from food production. Further investigation should be done to determine whether and what kind of agricultural

  16. Vegetation variation of loess deposits in the southeastern Inner Mongolia, NE China over the past ∼1.08 million years

    Science.gov (United States)

    Lyu, Anqi; Lu, Huayu; Zeng, Lin; Zhang, Hongyan; Zhang, Enlou; Yi, Shuangwen

    2018-04-01

    The stable carbon isotopic composition of organic matter of aeolian silt deposits is regarded as an appropriate proxy index of paleovegetation, especially in the Chinese Loess Plateau in central China. In this study, a loess-paleosol sequence in the southeastern Inner Mongolia Autonomous Region in northeastern (NE) China, which is located outside the Chinese Loess Plateau, is chosen to reconstruct the vegetation history since ∼1.08 Ma. Temperature exhibits a threshold value, which determines the growth of C4 plants in this study area. The organic matter of the samples is derived from two different vegetation types, namely, the mixed C3 and C4 plants and the pure C3 plants. The δ13C of the organic matter shows negative values in loess units and higher values in paleosol units. This finding reflects the influence of temperature and summer monsoon intensity on the vegetation dynamics over glacial-interglacial cycles. On a longer time scale, the δ13C values are higher between ∼1.1 and ∼0.9 Ma and after ∼0.35 Ma, and lower between ∼0.9 and ∼0.35 Ma, which may be attributed to a long-term temperature variation. Our analysis shows that regional temperature is the most important limiting factor that forces vegetation changes at the glacial-interglacial time scale in NE China.

  17. Variations of reflectance and vegetation indices as a function of the topographic modeling parameter of the Parque Estadual do Turvo, Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    William Gaida

    2016-11-01

    Full Text Available Remote sensing techniques have been widely used in forestry studies because they allow evaluation and monitoring of large areas. The Parque Estadual do Turvo (PET (17.491 ha is the largest fragment of preserved subtropical deciduous forest of South Brazil, representing an extension of the Misiones forest in Argentina (10.000 km². This area has great environmental importance and is adequate for performing remote sensing studies using high or even coarse-to-moderate spatial resolution data as well as related vegetation indices. Both, the reflectance and vegetation indices, are affected by external factors that change the spectral response of the surface components. Among the factors that can introduce errors in the interpretation of the images, topographic effects add spectral variability in satellite products. In addition, previous studies in subtropical forests showed that the geometry of data acquisition affects significantly the estimates of vegetation parameters derived from images acquired at off-nadir viewing or by large field-of-view (FOV sensors. This study aimed to evaluate the magnitude of the bidirectional reflectance variations and of the derived vegetation indices as a function of local topography using high spatial resolution data acquired by the RapidEye constellation of satellites.

  18. Quantitative variation in water-use efficiency across water regimes and its relationship with circadian, vegetative, reproductive, and leaf gas-exchange traits.

    Science.gov (United States)

    Edwards, Christine E; Ewers, Brent E; McClung, C Robertson; Lou, Ping; Weinig, Cynthia

    2012-05-01

    Drought limits light harvesting, resulting in lower plant growth and reproduction. One trait important for plant drought response is water-use efficiency (WUE). We investigated (1) how the joint genetic architecture of WUE, reproductive characters, and vegetative traits changed across drought and well-watered conditions, (2) whether traits with distinct developmental bases (e.g. leaf gas exchange versus reproduction) differed in the environmental sensitivity of their genetic architecture, and (3) whether quantitative variation in circadian period was related to drought response in Brassica rapa. Overall, WUE increased in drought, primarily because stomatal conductance, and thus water loss, declined more than carbon fixation. Genotypes with the highest WUE in drought expressed the lowest WUE in well-watered conditions, and had the largest vegetative and floral organs in both treatments. Thus, large changes in WUE enabled some genotypes to approach vegetative and reproductive trait optima across environments. The genetic architecture differed for gas-exchange and vegetative traits across drought and well-watered conditions, but not for floral traits. Correlations between circadian and leaf gas-exchange traits were significant but did not vary across treatments, indicating that circadian period affects physiological function regardless of water availability. These results suggest that WUE is important for drought tolerance in Brassica rapa and that artificial selection for increased WUE in drought will not result in maladaptive expression of other traits that are correlated with WUE.

  19. Examination of Automation-Induced Complacency and Individual Difference Variates

    Science.gov (United States)

    Prinzel, Lawrence J., III; DeVries, Holly; Freeman, Fred G.; Mikulka, Peter

    2001-01-01

    Automation-induced complacency has been documented as a cause or contributing factor in many airplane accidents throughout the last two decades. It is surmised that the condition results when a crew is working in highly reliable automated environments in which they serve as supervisory controllers monitoring system states for occasional automation failures. Although many reports have discussed the dangers of complacency, little empirical research has been produced to substantiate its harmful effects on performance as well as what factors produce complacency. There have been some suggestions, however, that individual characteristics could serve as possible predictors of performance in automated systems. The present study examined relationship between the individual differences of complacency potential, boredom proneness, and cognitive failure, automation-induced complacency. Workload and boredom scores were also collected and analyzed in relation to the three individual differences. The results of the study demonstrated that there are personality individual differences that are related to whether an individual will succumb to automation-induced complacency. Theoretical and practical implications are discussed.

  20. Comparative Study of Elemental Nutrients in Organic and Conventional Vegetables Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Bhatt, Chet R; Alfarraj, Bader; Ghany, Charles T; Yueh, Fang Y; Singh, Jagdish P

    2017-04-01

    In this study, the laser-induced breakdown spectroscopy (LIBS) technique was used to identify and compare the presence of major nutrient elements in organic and conventional vegetables. Different parts of cauliflowers and broccolis were used as working samples. Laser-induced breakdown spectra from these samples were acquired at optimum values of laser energy, gate delay, and gate width. Both univariate and multivariate analyses were performed for the comparison of these organic and conventional vegetable flowers. Principal component analysis (PCA) was taken into account for multivariate analysis while for univariate analysis, the intensity of selected atomic lines of different elements and their intensity ratio with some reference lines of organic cauliflower and broccoli samples were compared with those of conventional ones. In addition, different parts of the cauliflower and broccoli were compared in terms of intensity and intensity ratio of elemental lines.

  1. Activity-induced radial velocity variation of M dwarf stars

    DEFF Research Database (Denmark)

    Andersen, Jan Marie; Korhonen, Heidi Helena

    2012-01-01

    that can drown out a planetary signature. Cool, low-mass M dwarf stars can be highly active, which can make detection of potentially habitable planets around these stars difficult. We investigate radial velocity variations caused by different activity (spot) patterns on M dwarf stars in order to determine...... the limits of detectability for small planets orbiting active M dwarfs. We report on our progress toward the aim of answering the following questions: What types of spot patterns are realistic for M dwarf stars? What effect will spots have on M dwarf RV measurements? Can jitter from M dwarf spots mimic...... planetary signals? What is the ideal observing wavelength to reduce M dwarf jitter?...

  2. Variation in plant defenses of Didymopanax vinosum (Cham. & Schltdl. Seem. (Apiaceae across a vegetation gradient in a Brazilian cerrado

    Directory of Open Access Journals (Sweden)

    Pais Mara Patrícia

    2003-01-01

    Full Text Available Cerrado vegetation is composed of a mosaic of vegetation types, from campo sujo, dominated by herbs; campo cerrado and cerrado sensu stricto, with shrubby vegetation; to cerradão, with trees forming a denser forest. This physiognomic mosaic is related to differences in the water availability in the soil. Cerrado plants are considered physically and chemically well defended against herbivores, but there are no studies showing how plants allocate investment to various types of defensive mechanisms in different habitat physiognomies. The defensive mechanisms and the nutritional traits of a cerrado plant, Didymopanax vinosum (Cham. & Schltdl. Seem. (Apiaceae, were compared along a vegetation gradient. Toughness, as well as water, nitrogen, cellulose, lignin, and tannin contents were measured in young and mature leaves of D. vinosum collected in campo cerrado, cerrado sensu stricto (s.s. and cerradão. Plants from cerrado s.s. and cerradão were of better nutritional quality but also had higher tannin contents than campo cerrado plants. Some type of compensation mechanism could have been selected to provide an optimum investment in defense, according to limitations imposed by water deficits in the habitat.

  3. Transfer and Contact-Induced Variation in Child Basque

    Directory of Open Access Journals (Sweden)

    Jennifer eAustin

    2015-01-01

    Full Text Available Young Basque-speaking children produce Differential Object Marking (DOM and pre-verbal complementizers in their speech, variants argued to stem from contact with Spanish (Austin, 2006, Rodríguez-Ordóñez, 2013. In this paper, I claim that despite their contact-induced origin, these forms reflect distinct developmental tendencies on the part of the child acquiring Basque. Children's use of pre-verbal complementizers in Basque seems to be a relief strategy that bilingual children employ until they have acquired the post-verbal complementizers in Basque, which are low-frequency morphemes. In contrast, the use of DOM is present in the adult input, although children use this construction to a greater extent than adults do. Finally, I discuss the implications of these findings for the part that child learners play in advancing language change.

  4. Diurnal and Seasonal Variations of Eddy-Covariance Carbon Dioxide Fluxes Above an Urban Wetland, Partitioned by Vegetation Cover

    Science.gov (United States)

    Schafer, K. V.; Duman, T.

    2017-12-01

    The New Jersey Meadowlands are an urban brackish marsh with a long history of human activity causing disturbances and alterations. Carbon emissions were measured from two sites in the Meadowlands, a natural site and a restored site, using eddy-covariance (EC) from 2014 to 2016. At each site, the EC towers were placed at the interface of two vegetation covers, allowing capturing this aspect of the wetland's heterogeneity. Using footprint modeling and light response curves we were able to partition measured fluxes between vegetation cover types and compare CO2 fluxes from patches of invasive versus native wetland vegetation communities. We show that further separating the data into seasonal and diurnal fluxes reveals patterns in CO2 fluxes that allow determining the nature of each vegetation cover as a source or sink for CO2. Our results also show that CO2 emissions from the restored wetland are significantly higher than the natural wetland. Areas of invasive Phragmites australis at the natural site had the lowest CO2 release rates during winter. These were consistently lower in magnitude than summer daytime uptake, therefore making this part of the wetland a CO2 sink. Areas planted with native Spartina alterniflora at the restored site had the largest uptake during daytime, therefore seemingly justifying restoration activities. However, they also had the highest emission rates during summer nighttime, and therefore the daily summer net uptake was not the highest compared with other vegetation covers. Furthermore, emissions from the restored site during winter were larger compared to the natural site, indicating that restoration activities might have led to a significant increase of carbon release from the wetland. Thus, during the study period the restored wetland acted as a carbon source.

  5. Temporal-spatial variations and influencing factors of nitrogen in the shallow groundwater of the nearshore vegetable field of Erhai Lake, China.

    Science.gov (United States)

    Chen, Anqiang; Lei, Baokun; Hu, Wanli; Wang, Hongyuan; Zhai, Limei; Mao, Yanting; Fu, Bin; Zhang, Dan

    2018-02-01

    Nitrogen export from the nearshore vegetable field of Erhai Lake seriously threatens the water quality of Erhai Lake, which is the second largest highland freshwater lake in Yunnan Province, China. Among the nitrogen flows into Erhai Lake, shallow groundwater migration is a major pathway. The nitrogen variation and influencing factors in the shallow groundwater of the nearshore vegetable field of Erhai Lake are not well documented. A 2-year field experiment was conducted to determine the concentrations of nitrogen species in the shallow groundwater and their influencing factors in the nearshore vegetable field of Erhai Lake. The results showed that concentrations of TN, NO 3 - -N, and NO 2 - -N gradually increased with increasing elevation and distance from Erhai Lake, but the opposite was observed for NH 4 + -N in the shallow groundwater. The concentrations of nitrogen species in the rainy season were greater than those in the dry season. NO 3 - -N accounted for more than 79% of total nitrogen in shallow groundwater. Redundancy analysis showed that more than 70% of the temporal and spatial variations of nitrogen concentrations in the shallow groundwater were explained by shallow groundwater depth, and only approximately 10% of variation was explained by the factors of soil porosity, silt clay content of soil, and NH 4 + -N and NO 3 - -N concentrations of soil (p shallow groundwater depth had more notable effects on nitrogen concentrations in the shallow groundwater than other factors. This result will strongly support the need for further research regarding the management practices for reducing nitrogen concentrations in shallow groundwater.

  6. Stress-induced variation in evolution: from behavioural plasticity to genetic assimilation.

    Science.gov (United States)

    Badyaev, Alexander V

    2005-05-07

    Extreme environments are closely associated with phenotypic evolution, yet the mechanisms behind this relationship are poorly understood. Several themes and approaches in recent studies significantly further our understanding of the importance that stress-induced variation plays in evolution. First, stressful environments modify (and often reduce) the integration of neuroendocrinological, morphological and behavioural regulatory systems. Second, such reduced integration and subsequent accommodation of stress-induced variation by developmental systems enables organismal 'memory' of a stressful event as well as phenotypic and genetic assimilation of the response to a stressor. Third, in complex functional systems, a stress-induced increase in phenotypic and genetic variance is often directional, channelled by existing ontogenetic pathways. This accounts for similarity among individuals in stress-induced changes and thus significantly facilitates the rate of adaptive evolution. Fourth, accumulation of phenotypically neutral genetic variation might be a common property of locally adapted and complex organismal systems, and extreme environments facilitate the phenotypic expression of this variance. Finally, stress-induced effects and stress-resistance strategies often persist for several generations through maternal, ecological and cultural inheritance. These transgenerational effects, along with both the complexity of developmental systems and stressor recurrence, might facilitate genetic assimilation of stress-induced effects. Accumulation of phenotypically neutral genetic variance by developmental systems and phenotypic accommodation of stress-induced effects, together with the inheritance of stress-induced modifications, ensure the evolutionary persistence of stress-response strategies and provide a link between individual adaptability and evolutionary adaptation.

  7. Mood-induced variations of mandible and tongue postures.

    Science.gov (United States)

    Bourdiol, P; Mishellany-Dutour, A; Peyron, M-A; Woda, A

    2013-06-01

    Twelve young adults in a good general health were observed during habitual posture of tongue and jaw in different emotional conditions induced by watching three video sequences. The position of the mandible was tracked by the displacements of an electromagnetic sensor glued to the chin. The tongue-to-palate distance was obtained by 2-D location of three electromagnetic sensors placed on the tongue upper midline surface. Head displacements were evaluated with a sensor fixed to an upper central incisor and were subtracted from corresponding displacements of tongue and chin sensors to obtain the real tongue and mandible positions during continuous recording sequences. Emotional conditioning by a fear movie influenced the vertical position of the mandible: the mean interarch distances during the fear movie (2·34 ± 0·24 mm) were significantly different from those measured during the tender (3·13 ± 0·35) and neutral (3·42 ± 0·80) movies, respectively (anova repeated measure, SNK; P < 0·05). anova repeated measure indicated that the tongue-to-palate distance differed significantly when the subjects were watching the conditioning movies (P = 0·003), the tip of the tongue taking a lower position during the fear movie than during the tender and neutral movies. © 2013 John Wiley & Sons Ltd.

  8. Large-scale drought-induced vegetation die-off: expanding the ecohydrological emphasis more explicitly on atmospheric demand. (Invited)

    Science.gov (United States)

    Breshears, D. D.; Adams, H. D.; Eamus, D.; McDowell, N. G.; Law, D. J.; Will, R. E.; Williams, P.; Zou, C.

    2013-12-01

    Ecohydrology focuses on the interactions of water availability, ecosystem productivity, and biogeochemical cycles via ecological-hydrological connections. These connections can be particularly pronounced and socially relevant when there are large-scale rapid changes in vegetation. One such key change, vegetation mortality, can be triggered by drought and is projected to become more frequent and/or extensive in the future under changing climate. Recent research on drought-induced vegetation die-off has focused primarily on direct drought effects, such as soil moisture deficit, and, to a much lesser degree, the potential for warmer temperatures to exacerbate stress and accelerate mortality. However, temperature is tightly interrelated with atmospheric demand (vapor pressure deficit, VPD) but the latter has rarely been considered explicitly relative to die-off events. Here we highlight the importance of VPD in addition to soil moisture deficit and warmer temperature as an important driver of future die-off. Recent examples highlighting the importance of VPD include mortality patterns corresponding to VPD drivers, a strong dependence of forest growth on VPD, patterns of observed mortality along an environmental gradient, an experimentally-determined climate envelope for mortality, and a suite of modeling simulations segregating the drought effects of VPD from those of temperature. The vast bulk of evidence suggests that atmospheric demand needs to be considered in addition to temperature and soil moisture deficit in predicting risk of future vegetation die-off and associated ecohydrological transformations.

  9. Effect of temperature variations during cooking and storage on ascorbic acid contents of vegetables: a comparative study

    International Nuclear Information System (INIS)

    Zaman, W.U.; Akram, M.; Rehman, R.

    2013-01-01

    Summary: Vegetables are generally boiled for cooking or stored in refrigerators. This results in loss of their nutritional values. Ascorbic acid is one of the important nutrients for human health. In this study, Ascorbic acid (vitamin-C) content of various vegetables of Pakistan was determined, and effect of boiling and freezing were compared with natural Ascorbic acid contents by HPLC. The maximum concentration of Ascorbic acid was found in green chilli: i.e. 105 mg /100 g in fresh state; while in boiled and frozen state its concentration is comparatively less: i.e. 85 and 92 mg/100 g respectively. The other vegetables like: cabbage, to mato, turnip, potato, spinach, onion, garlic, green pea, green beans and cauliflower contained greater amount of Ascorbic acid in their fresh state i.e. 30, 20, 25.3, 20, 30, 24.3, 31, 28.5, 30, 42 mg/100 g as compared to frozen (23.4, 13, 23.6, 15, 23.4, 14.1,25, 26.5, 27.0, and 39 mg/100g respectively) and boiled state (11.6, 9.3, 22.5, 10.0, 20.3, 13.1, 23, 25.2 and 35 mg /100g respectively). The minimum amount of Ascorbic acid was found in boiled state of carrot and lettuce: i.e. 4.0 mg/100 g. These results showed that freezing or boiling of vegetables causes significant lo ss of available Ascorbic acid contents, especially boiling. (author)

  10. Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. M. Dupont

    2011-11-01

    Full Text Available Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean ∼120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome for the last glacial as well as for other glacial periods of the past 300 Ka.

  11. Temporal and spatial variation of habitat conditions in the zonation of vegetation in the late stages of lake overgrowth

    Directory of Open Access Journals (Sweden)

    Stanisław Kłosowski

    2014-01-01

    Full Text Available The water and substrate properties in the vegetation zones characteristic of the late stages of lake overgrowth were determined. It was demonstrated that the spatial distribution of plant communities conformed with the spatial gradient of habitat conditions. With regard to water properties the largest differences between the zones were found in Mg2+, Ca2+, electrolytic conductivity and NH4+. In the case of substrate the zones differed significantly in Ca2+, total Fe and organic matter content. The water properties varied greatly during the vegetative season in the successive zones. The temporal changes often proceeded at a different level of a given component or factor in most zones. The differences between the zones were, however, maintained. It appears that the plant communities can alter their habitats to a large extent. In the lake studied, the invasion of raised and transitional bog vegetation was observed. The process of dystrophy proceeded from the terrestrialized peripheral parts of the lake to the centre of the lake.

  12. Biological variation in tPA-induced plasma clot lysis time.

    Science.gov (United States)

    Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

    2012-10-01

    Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

  13. [Variation characteristics and influencing factors of actual evapotranspiration under various vegetation types: A case study in the Huaihe River Basin, China.

    Science.gov (United States)

    Wu, Rong Jun; Xing, Xiao Yong

    2016-06-01

    The actual evapotranspiration was modelled utilizing the boreal ecosystem productivity simulator (BEPS) in Huaihe River Basin from 2001 to 2012. In the meantime, the quantitative analyses of the spatial-temporal variations of actual evapotranspiration characteristics and its influencing factors under different vegetation types were conducted. The results showed that annual evapotranspiration gradually decreased from southeast to northwest, tended to increase annually, and the monthly change for the average annual evapotranspiration was double-peak curve. The differences of evapotranspiration among vegetation types showed that the farmland was the largest contributor for the evapotranspiration of Huaihe Basin. The annual actual evapotranspiration of the mixed forest per unit area was the largest, and that of the bare ground per unit area was the smallest. The changed average annual evapotranspiration per unit area for various vegetation types indicated an increased tendency other than the bare ground, with a most significant increase trend for the evergreen broadleaf forest. The thermodynamic factors (such as average temperature) were the dominant factors affecting the actual evapotranspiration in the Huaihe Basin, followed by radiation and moisture factors.

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

    Science.gov (United States)

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

    2015-09-01

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

  15. Determination of Elemental Composition of Malabar spinach, Lettuce, Spinach, Hyacinth Bean, and Cauliflower Vegetables Using Proton Induced X-Ray Emission Technique at Savar Subdistrict in Bangladesh

    Directory of Open Access Journals (Sweden)

    S. M. Fahad

    2015-01-01

    Full Text Available The concentrations of 18 different elements (K, Ca, Fe, Cl, P, Zn, S, Mn, Ti, Cr, Rb, Co, Br, Sr, Ru, Si, Ni, and Cu were analyzed in five selected vegetables through Proton Induced X-ray Emission (PIXE technique. The objective of this study was to provide updated information on concentrations of elements in vegetables available in the local markets at Savar subdistrict in Bangladesh. These elements were found in varying concentrations in the studied vegetables. The results also indicated that P, Cl, K, Ca, Mn, Fe, and Zn were found in all vegetables. Overall, K and Ca exhibited the highest concentrations. Cu and Ni exhibited the lowest concentrations in vegetables. The necessity of these elements was also evaluated, based on the established limits of regulatory standards. The findings of this study suggest that the consumption of these vegetables is not completely free of health risks.

  16. Impacts of Climate Change Induced Vegetation Responses on BVOC Emissions from Subarctic Heath Ecosystems

    DEFF Research Database (Denmark)

    Valolahti, Hanna Maritta

    The role of biogenic volatile organic compounds (BVOCs) affecting Earths’ climate system is one of the greatest uncertainties when modelling the global climate change. BVOCs presence in the atmosphere can have both positive and negative climate feedback mechanisms when they involve atmospheric...... chemistry and physics. Vegetation is the main source of BVOCs. Their production is directly linked to temperature and the foliar biomass. On global scale, vegetation in subarctic and arctic regions has been modeled to have only minor contribution to annual total BVOC emissions. In these regions cold...... temperature has been regulating annual plant biomass production, but ongoing global warming is more pronounced in these regions than what the global average is. This may increase the importance of subarctic and arctic vegetation as a source of BVOC emissions in near future. This thesis aims to increase...

  17. Analysis of the spatial-temporal variation characteristics of vegetative drought and its relationship with meteorological factors in China from 1982 to 2010.

    Science.gov (United States)

    Shen, Qiu; Liang, Liang; Luo, Xiang; Li, Yanjun; Zhang, Lianpeng

    2017-08-25

    Drought is a complex natural phenomenon that can cause reduced water supplies and can consequently have substantial effects on agriculture and socioeconomic activities. The objective of this study was to gain a better understanding of the spatial-temporal variation characteristics of vegetative drought and its relationship with meteorological factors in China. The Vegetation Condition Index (VCI) dataset calculated from NOAA/AVHRR images from 1982 to 2010 was used to analyse the spatial-temporal variation characteristics of vegetative drought in China. This study also examined the trends in meteorological factors and their influences on drought using monitoring data collected from 686 national ground meteorological stations. The results showed that the VCI appeared to slowly rise in China from 1982 to 2010. From 1982 to 1999, the VCI rose slowly. Then, around 2000, the VCI exhibited a severe fluctuation before it entered into a relatively stable stage. Drought frequencies in China were higher, showing a spatial distribution feature of "higher in the north and lower in the south". Based on the different levels of drought, the frequencies of mild and moderate drought in four geographical areas were higher, and the frequency of severe drought was higher only in ecologically vulnerable areas, such as the Tarim Basin and the Qaidam Basin. Drought was mainly influenced by meteorological factors, which differed regionally. In the northern region, the main influential factor was sunshine duration, while the other factors showed minimal effects. In the southern region and Tibetan Plateau, the main influential factors were sunshine duration and temperature. In the northwestern region, the main influential factors were wind velocity and station atmospheric pressure.

  18. Variations in Vegetation Structure, Species Dominance and Plant Communities in South of the Eastern Desert-Egypt

    Directory of Open Access Journals (Sweden)

    Fawzy SALAMA

    2014-03-01

    Full Text Available For two successive years, the floristic diversity and vegetation composition in the southern part of the Eastern Desert ofEgypt were investigated through four transects (3 crossing the Eastern Desert and one along the Red Sea. The data collected from 142 stands covering the study area included the species composition, functional groups, chorology and occurrences (Qvalues. A total of 94 plant species belonging to 33 different families were recorded, with Asteracea, Zygophyllaceae, Fabaceae,Poaceae, Chenopodiaceae and Brassicaceae as the largest families. Shrubs represented the largest functional group (39.4%, while perennial herbs represented the smallest ones (12.8%. Species occurrence (Q-value revealed that Zilla spinosa, Acacia tortilis subsp raddiana, Morettia philaeana, Caroxylon imbricatum, Zygophyllum coccineum and Citrullus colocynthis had wide ecological range of distribution (dominant species, Q-values 0.2. Saharo-Arabian chorotype was highly represented (72.6 % in the flora of this area, eventually as mono, bi or pluriregional. Classification of the data set yielded 7 vegetation groups included: (A Zilla spinosa-Morettia philaeana, (B1 Zilla spinosa-Citrullus colocynthis-Morettia philaeana, (B2 Zilla spinosa, (C1Zygophyllum album-Tamarix nilotica, (C2 Zygophyllum coccineum-Tamarix nilotica, (D1 Zilla spinosa-Zygophyllum coccineum and (D2 Zilla spinosa-Acacia tortilis subsp. raddiana-Tamarix aphylla-Balanites aegyptiaca. Certain vegetation groups were assigned to one or more transects. Detrended Correspondence Analysis (DCA revealed that electrical conductivity, sodium, potassium, calcium, magnesium, chlorides, moisture content, sulphates, pH, organic matter and gravel were the soil variables that affect the species distribution in this study.

  19. Evaluating theories of drought-induced vegetation mortality using a multimodel-experiment framework

    Science.gov (United States)

    Nate G. McDowell; Rosie A. Fisher; Chonggang Xu; J. C. Domec; Teemu Holtta; D. Scott Mackay; John S. Sperry; Amanda Boutz; Lee Dickman; Nathan Gehres; Jean Marc Limousin; Alison Macalady; Jordi Martinez-Vilalta; Maurizio Mencuccini; Jennifer A. Plaut; Jerome Ogee; Robert E. Pangle; Daniel P. Rasse; Michael G. Ryan; Sanna Sevanto; Richard H. Waring; A. Park Williams; Enrico A. Yepez; William T. Pockman

    2013-01-01

    Model-data comparisons of plant physiological processes provide an understanding of mechanisms underlying vegetation responses to climate. We simulated the physiology of a pinon pine-juniper woodland (Pinus edulis-Juniperus monosperma) that experienced mortality during a 5 yr precipitation-reduction experiment, allowing a framework with which to examine our knowledge...

  20. Gamma ray induced fruit quality variations in banana variety Nendran (Musa Paradasiaca L.)

    International Nuclear Information System (INIS)

    Radha Devi, D.S.; Nayer, N.K.

    1992-01-01

    Gamma ray induced fruit quality variation was envisaged to analyse the direct effect of Co 60 gamma rays in banana variety Nendran. Fruit quality analysis showed that the total soluble solids and acidity decreased and total sugar and sugar acid ratio increased with increase in dose of gamma ray exposures. (author). 5 refs., 1 tab

  1. Accounting Fundamentals and Variations of Stock Price: Forward Looking Information Inducement

    OpenAIRE

    Sumiyana, Sumiyana

    2011-01-01

    This study investigates a permanent issue about low association between accounting fundamentals and variations of stock prices. It induces not only historical accountingfundamentals, but also forward looking information. Investors consider forward looking information that enables them to predict potential future cash flow, increase predictive power, lessen mispricing error, increase information content and drives future price equilibrium. The accounting fundamentals are earnings yield, book v...

  2. Induced variation in potato dry rot fusarium roseum by ultraviolet irradiation

    International Nuclear Information System (INIS)

    Lee, C.U.

    1979-01-01

    Variations were readily induced in Fusarium roseum isolated from decayed potato tubers by subjecting its conidia to ultraviolet irradiation. The dosage that resulted in complete absence of developing colonies in five minutes of irradiation did not cause the mortality of conidia for the initial one minute. Eighty eight precent of conidia were killed in three minutes. Approximately 90% of the conidia showed resistance to lethality for the initial two minutes whereas 10% began to show resistance after three minutes of the irradiation. The maximum 42% of color variation was obtained among the surviving conidia. Varients in both decreased and increased pathogenicity were induced in 8% among the color variants. Variations occurred in such other characteristics as growth rate, rigidity of mycelium, and conidia formation. (author)

  3. Day-night variation in heart rate variability changes induced by endotoxaemia in healthy volunteers

    DEFF Research Database (Denmark)

    Alamili, M.; Rosenberg, J; Gögenur, I

    2015-01-01

    /night variation in endotoxaemia-induced changes in HRV. METHODS: A randomized, crossover study with 12 healthy men (age 18-31) was conducted. Endotoxaemia were induced by lipopolysaccharide (LPS) endotoxin 0.3 ng/kg b.w. in two visits (day visit and night visit). At the day visit, endotoxaemia were induced at 12...... at both night and day resulted in a significant depression in HRV parameters high-frequency power (HF), low-frequency power (LF), standard deviation of normal-to-normal (NN) intervals, root mean square of successive differences and proportion of NN50 divided by total number of NNs (P

  4. Prospects of hydrocarbon deposits exploration using the method of induced polarization during geomagnetic-variation profiling

    Directory of Open Access Journals (Sweden)

    К. М. Ермохин

    2017-10-01

    Full Text Available Traditionally it is believed that the effect of induced polarization is an interfering factor for the measurement of electromagnetic fields and their interpretation during conducting works using magnetotelluric sounding and geomag-netic-variation profiling methods. A new method is proposed for isolating the effects of induced polarization during geomagnetic-variation profiling aimed at searching for hydrocarbon deposits on the basis of phase measurements during the conduct of geomagnetic-variation profiling. The phenomenon of induced polarization is proposed to be used as a special exploration mark for deep-lying hydrocarbon deposits. The traditional method of induced polarization uses artificial field sources, the powers of which are principally insufficient to reach depths of 3-5 km, which leads to the need to search for alternative - natural sources in the form of telluric and magnetotelluric fields. The proposed method makes it possible to detect and interpret the effects of induced polarization from deep-seated oil and gas reservoirs directly, without relying on indirect signs.

  5. Study on character variation induced by introducing exogenous DNA into upland cotton with ion implantation

    International Nuclear Information System (INIS)

    Cheng Beijiu; Tian Qiuyuan; Li Zhan; Zhou Liren

    1996-01-01

    The exogenous DNAs of G. Bickll P. and H. Cannabinus were introduced into the upland cotton Si 2 by Ar + implantation and DNA solution trickling method. The results showed that the exogenous DNA introduction was promoted significantly and the types and frequencies of character variation in progeny were increased by Ar + implantation. Furthermore, most of the variation tend to be stable. Among the Ar + implantation doses tested, 2 x 10 15 Ar + /cm 2 was the best for introducing exogenous DNA and inducing character variation, the variation rate reached to 16.2%. Some new lines with character of resistance to wilt disease, early maturity, few gland in seed and fine fiber quality have been obtained

  6. Induced variation in pod and seed traits of wild and cultivated beans

    International Nuclear Information System (INIS)

    Ignacimuthu, S.; Babu, C.R.

    1992-01-01

    With a view to evaluate the induced genetic variation in yield traits of wild and cultivated urd and mung bean, seeds of Vigna radiata. V. mungo (cultivars) and V. sublobata (wild relative) were given mutagenic treatments. Different concentrations of EMS and gamma rays were used as mutagens separately and in combination. Genetic variation in yield traits was analysed in M 2 plants. There was a broad spectrum of induced variability in most yield traits. Genetic variance, heritability and genetic advance were high in most of the traits. The results demonstrate that induced mutations are random, polydirectional and quantitative in nature. The wild relative is more resistant than the cultivars. (author). 14 refs., 4 tabs

  7. Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models.

    Science.gov (United States)

    Johnson, Michelle O; Galbraith, David; Gloor, Manuel; De Deurwaerder, Hannes; Guimberteau, Matthieu; Rammig, Anja; Thonicke, Kirsten; Verbeeck, Hans; von Randow, Celso; Monteagudo, Abel; Phillips, Oliver L; Brienen, Roel J W; Feldpausch, Ted R; Lopez Gonzalez, Gabriela; Fauset, Sophie; Quesada, Carlos A; Christoffersen, Bradley; Ciais, Philippe; Sampaio, Gilvan; Kruijt, Bart; Meir, Patrick; Moorcroft, Paul; Zhang, Ke; Alvarez-Davila, Esteban; Alves de Oliveira, Atila; Amaral, Ieda; Andrade, Ana; Aragao, Luiz E O C; Araujo-Murakami, Alejandro; Arets, Eric J M M; Arroyo, Luzmila; Aymard, Gerardo A; Baraloto, Christopher; Barroso, Jocely; Bonal, Damien; Boot, Rene; Camargo, Jose; Chave, Jerome; Cogollo, Alvaro; Cornejo Valverde, Fernando; Lola da Costa, Antonio C; Di Fiore, Anthony; Ferreira, Leandro; Higuchi, Niro; Honorio, Euridice N; Killeen, Tim J; Laurance, Susan G; Laurance, William F; Licona, Juan; Lovejoy, Thomas; Malhi, Yadvinder; Marimon, Bia; Marimon, Ben Hur; Matos, Darley C L; Mendoza, Casimiro; Neill, David A; Pardo, Guido; Peña-Claros, Marielos; Pitman, Nigel C A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Roopsind, Anand; Rudas, Agustin; Salomao, Rafael P; Silveira, Marcos; Stropp, Juliana; Ter Steege, Hans; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van der Heijden, Geertje M F; Vasquez, Rodolfo; Guimarães Vieira, Ima Cèlia; Vilanova, Emilio; Vos, Vincent A; Baker, Timothy R

    2016-12-01

    Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  8. Line-edge roughness induced single event transient variation in SOI FinFETs

    International Nuclear Information System (INIS)

    Wu Weikang; An Xia; Jiang Xiaobo; Chen Yehua; Liu Jingjing; Zhang Xing; Huang Ru

    2015-01-01

    The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

  9. Micaceous Soil Strength And Permeability Improvement Induced By Microbacteria From Vegetable Waste

    Science.gov (United States)

    Omar, R. C.; Roslan, R.; Baharuddin, I. N. Z.; Hanafiah, M. I. M.

    2016-11-01

    Green technology method using vegetable waste are introduced in this paper for improvement of phyllite residual soil from UNITEN, Campus. Residual soil from phyllite are known as micaceous soils and it give problem in managing the stability of the slope especially in wet and extensively dry seasons. Micaceous soil are collected using tube sampler technique and mixed with liquid contain microorganism from fermented vegetable waste name as vege-grout to form remolded sample. The remolded sample are classify as 15.0%, 17.5%, 20.00% and 22.5% based on different incremental percentages of vege-grout. The curing time for the sample are 7, 14, 21, 28, and 35 days before the tests were conducted. Observation of the effect of treatment shows 20.0% of liquid contain Bacillus pasteurii and Bacillus Subtilis with 21 days curing time is the optimum value in strengthening the soil and improve the permeability.

  10. Induced mutagenesis as a breeding strategy for improvement of Solanaceous vegetables

    International Nuclear Information System (INIS)

    Masuda, Masaharu; Ojiewo, Christopher O.

    2008-01-01

    The Solanaceae are a cosmopolitan family containing many essential vegetables and fruits such as potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum L.), eggplant (Solanum melongena L.), paprika, chillies, green and red peppers (Capsicum annuum L.), jasmine nightshade (Solanum jasminoides Paxt.), winter cherry (Solanum pseudocapsicum L.), and Cape gooseberry, ornamentals such as Petunia, Schizanthus, and Lycium species, and medicinal plants such as bittersweet (Solanum dulcamara L.) and Solanum viarum Dun., both used as sources of corticosteroids. It also contains tobacco (Nicotiana spp.) - one of the most harmful yet economically important plants in the world - together with many other plants of both poisonous and medicinal value such as belladonna (Atropa belladona L.), stramonium (Datura stramonium L.), black henbane (Hyoscyamus niger L.), and African nightshade (Solanum villosum). Composed of approximately 90 genera and between 2000 and 3000 species, the family is widely distributed throughout the tropical and temperate regions of the world, with centers of diversity occurring in Central and South America, Australia, and Africa (EDMONDS 1978; SYMON 1981; D'ARCY 1991). Work to develop new varieties of improved solanaceous crops started more than 2 centuries ago. This paper reviews some of the recent developments in various aspects of varietal improvement of solanaceous vegetables through mutation breeding. Mutational work reported here includes the alteration of plant reproductive or vegetative growth and the development of locally adapted cultivars and popular breeding lines, or the induction of novel alleles. The potential for direct application of the mutants as new improved cultivars, their use in cross-breeding schemes, and their application in, for example, marker technology in genetic research are discussed. Specific examples of novel mutants developed in our laboratory that have the potential for application in improving solanaceous fruits

  11. Spatial variation and linkages of soil and vegetation in the Siberian Arctic tundra – coupling field observations with remote sensing data

    Directory of Open Access Journals (Sweden)

    J. Mikola

    2018-05-01

    Full Text Available Arctic tundra ecosystems will play a key role in future climate change due to intensifying permafrost thawing, plant growth and ecosystem carbon exchange, but monitoring these changes may be challenging due to the heterogeneity of Arctic landscapes. We examined spatial variation and linkages of soil and plant attributes in a site of Siberian Arctic tundra in Tiksi, northeast Russia, and evaluated possibilities to capture this variation by remote sensing for the benefit of carbon exchange measurements and landscape extrapolation. We distinguished nine land cover types (LCTs and to characterize them, sampled 92 study plots for plant and soil attributes in 2014. Moreover, to test if variation in plant and soil attributes can be detected using remote sensing, we produced a normalized difference vegetation index (NDVI and topographical parameters for each study plot using three very high spatial resolution multispectral satellite images. We found that soils ranged from mineral soils in bare soil and lichen tundra LCTs to soils of high percentage of organic matter (OM in graminoid tundra, bog, dry fen and wet fen. OM content of the top soil was on average 14 g dm−3 in bare soil and lichen tundra and 89 g dm−3 in other LCTs. Total moss biomass varied from 0 to 820 g m−2, total vascular shoot mass from 7 to 112 g m−2 and vascular leaf area index (LAI from 0.04 to 0.95 among LCTs. In late summer, soil temperatures at 15 cm depth were on average 14 °C in bare soil and lichen tundra, and varied from 5 to 9 °C in other LCTs. On average, depth of the biologically active, unfrozen soil layer doubled from early July to mid-August. When contrasted across study plots, moss biomass was positively associated with soil OM % and OM content and negatively associated with soil temperature, explaining 14–34 % of variation. Vascular shoot mass and LAI were also positively associated with soil OM content, and LAI with active layer

  12. Effects of Respiration-Induced Density Variations on Dose Distributions in Radiotherapy of Lung Cancer

    International Nuclear Information System (INIS)

    Mexner, Vanessa; Wolthaus, Jochem W.H.; Herk, Marcel van; Damen, Eugene M.F.; Sonke, Jan-Jakob

    2009-01-01

    Purpose: To determine the effect of respiration-induced density variations on the estimated dose delivered to moving structures and, consequently, to evaluate the necessity of using full four-dimensional (4D) treatment plan optimization. Methods and Materials: In 10 patients with large tumor motion (median, 1.9 cm; range, 1.1-3.6 cm), the clinical treatment plan, designed using the mid-ventilation ([MidV]; i.e., the 4D-CT frame closest to the time-averaged mean position) CT scan, was recalculated on all 4D-CT frames. The cumulative dose was determined by transforming the doses in all breathing phases to the MidV geometry using deformable registration and then averaging the results. To determine the effect of density variations, this cumulative dose was compared with the accumulated dose after similarly deforming the planned (3D) MidV-dose in each respiratory phase using the same transformation (i.e., 'blurring the dose'). Results: The accumulated tumor doses, including and excluding density variations, were almost identical. Relative differences in the minimum gross tumor volume (GTV) dose were less than 2% for all patients. The relative differences were even smaller in the mean lung dose and the V20 (<0.5% and 1%, respectively). Conclusions: The effect of respiration-induced density variations on the dose accumulated over the respiratory cycle was very small, even in the presence of considerable respiratory motion. A full 4D-dose calculation for treatment planning that takes into account such density variations is therefore not required. Planning using the MidV-CT derived from 4D-CT with an appropriate margin for geometric uncertainties is an accurate and safe method to account for respiration-induced anatomy variations.

  13. Effect of Water Deficit-Induced at Vegetative and Reproductive Stages on Protein and Oil Content in Soybean Grains

    Directory of Open Access Journals (Sweden)

    Liliane M. Mertz-Henning

    2017-12-01

    Full Text Available Soybean is one of the most common grain crops worldwide, representing an important protein and oil source. Although genetic variability in the chemical composition of grains is seen in soybean, the mean levels of proteins have remained stagnant or, in some cases, have decreased over time, arousing concern in the agricultural industry. Furthermore, environmental conditions influence the chemical composition of grains. Thus, the present study evaluated the effect of water deficit (WD induced at the vegetative period (vegetative stress (VS and reproductive period (reproductive stress (RS on the protein and oil contents of grains in different soybean genotypes. Yield and its components were evaluated to evaluate the interrelation of these traits. The experiment was completed over three crop seasons under field conditions in Londrina, Paraná (PR, Brazil. WD was induced using rainout shelters and then stress treatments with irrigated and non-irrigated conditions were compared. WD negatively affected yield and its components. All evaluated genotypes showed similar responses for oil and protein contents under different water conditions. Higher protein content and lower oil content were observed in grains under RS. Such a relationship was not equally established under VS. Additionally, negative relationships between protein and oil content and between protein content and yield were confirmed.

  14. Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014.

    Science.gov (United States)

    Ma, Jun; Xiao, Xiangming; Zhang, Yao; Doughty, Russell; Chen, Bangqian; Zhao, Bin

    2018-10-15

    Accurately estimating spatial-temporal patterns of gross primary production (GPP) is important for the global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatial-temporal dynamics of GPP. However, the accuracy assessment of GPP simulations from LUE models at both spatial and temporal scales remains a challenge. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images with 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPP VPM ) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPP VPM and SIF data over a single year (2010) and multiple years (2007-2014) in most areas of China. GPP VPM is also significantly positive correlated with GOME-2 SIF (R 2  > 0.43) spatially for seasonal scales. However, poor consistency was detected between GPP VPM and SIF data at yearly scale. GPP dynamic trends have high spatial-temporal variation in China during 2007-2014. Temperature, leaf area index (LAI), and precipitation are the most important factors influence GPP VPM in the regions of East Qinghai-Tibet Plateau, Loss Plateau, and Southwestern China, respectively. The results of this study indicate that GPP VPM is temporally and spatially in line with GOME-2 SIF data, and space-borne SIF data have great potential for evaluating LUE-based GPP models. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. WILDFIRE INDUCED DEGRADATION OF WOODY VEGETATION IN DRY ZONE OF KAZAKHSTAN

    Directory of Open Access Journals (Sweden)

    A. Terekhov

    2012-08-01

    Full Text Available Small bushy tree species dominate the semi-arid areas of Kazakhstan. In the course of their life cycle, they form a layer of litter that is resistant to wind transport. This small shrub species with its own litter play a significant role in the spectral characteristics of the Earth surface. Changes in the density of shrub canopy forms or replacing them with herbaceous species is accompanied by significant changes in the spectral characteristics in the visible and near infrared spectral bands in the autumn. These changes can be recorded from satellite data. LANDSAT-TM images during 1985–2007 years and MODIS data (USGS: MOD09Q1, 2000–2010 used to diagnose changes in relation between woody\\herbaceous vegetation species in the dry zone of Kazakhstan. It was found that over the past 10 years, spreading small shrub forms of semi-arid vegetation significantly decreased. There is a persistent expansion of herbal forms, leading to the semi-steppe formation areas. The mechanism of repression of wood forms constructed through the accumulation of dry plant mass during wet years, with its subsequent burnout during wildfires. In the case of a strong fire, a complete destruction of species is observed. The restoration of small shrub cover demands more than 20 years. Comparative analysis of LANDSAT-TM images showed a 10 times increasing of the fire scar areas in the test area in the central part of Kazakhstan between 1985 and 2007. According MOD09Q1 was conducted mapping small shrub forms of degradation in Kazakhstan. Reducing the area occupied by woody vegetation, semi-desert was about 30 million hectares or over 30% of their total range in Kazakhstan.

  16. Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation.

    Science.gov (United States)

    Dawes, Melissa A; Philipson, Christopher D; Fonti, Patrick; Bebi, Peter; Hättenschwiler, Stephan; Hagedorn, Frank; Rixen, Christian

    2015-05-01

    Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning. © 2014 John Wiley & Sons Ltd.

  17. Human-Induced Vegetation Degradation in a Semi-Arid Rangeland

    Science.gov (United States)

    Jackson, Hasan

    Current assessments of anthropogenic land degradation and its impact on vegetation at regional scales are prone to large uncertainties due to the lack of an objective, transferable, spatially and temporally explicit measure of land degradation. These uncertainties have resulted in contradictory estimates of degradation extent and severity and the role of human activities. The uncertainties limit the ability to assess the effects on the biophysical environment and effectiveness of past, current, and future policies of land use. The overall objective of the dissertation is to assess degradation in a semi-arid region at a regional scale where the process of anthropogenic land degradation is evident. Net primary productivity (NPP) is used as the primary indicator to measure degradation. It is hypothesized that land degradation resulting from human factors on the landscape irreversibly reduces NPP below the potential set by environmental conditions. It is also hypothesized that resulting reductions in NPP are distinguishable from natural, spatial and temporal, variability in NPP. The specific goals of the dissertation are to (1) identify the extent and severity of degradation using productivity as the primary surrogate, (2) compare the degradation of productivity to other known mechanisms of degradation, and (3) relate the expression of degradation to components of vegetation and varying environmental conditions. This dissertation employed the Local NPP Scaling (LNS) approach to identify patterns of anthropogenic degradation of NPP in the Burdekin Dry Tropics (BDT) region of Queensland (14 million hectares), Australia from 2000 to 2013. The method started with land classification based on the environmental factors presumed to control NPP to group pixels having similar potential NPP. Then, satellite remotely sensing data were used to compare actual NPP with its potential. The difference, in units of mass of carbon fixed in NPP per unit area per monitoring interval and

  18. Radiation-induced transmission spectral variations of Ce3+-doped heavy germanate glasses

    International Nuclear Information System (INIS)

    Yang Yunxia; Baccaro, S.; Cecilia, A.; Rao Jinhua; Zhang Junbiao; Xia Fang; Chen Guorong

    2005-01-01

    Radiation-induced transmission spectral variations of Ce 3+ -doped heavy germanate glasses used as scintillating materials are presented. Glass matrix contains mainly GeO 2 , BaO and Gd 2 O 3 with a density higher than 5 g/cm 3 . Glasses are melted in the different atmosphere. The transmission spectra of glasses before and after radiation treatments are measured and compared. Unlike exhibiting the monotonous deterioration effect on the glass matrix, radiation plays the radiation protection role, even making enhanced transmission of Ce 3+ -doped glasses, depending upon glass melting atmosphere and radiation dose. Radiation-induced reducing and oxidizing mechanism is proposed to explain phenomena

  19. Using induced pluripotent stem cells to explore genetic and epigenetic variation associated with Alzheimer's disease.

    Science.gov (United States)

    Imm, Jennifer; Kerrigan, Talitha L; Jeffries, Aaron; Lunnon, Katie

    2017-11-01

    It is thought that both genetic and epigenetic variation play a role in Alzheimer's disease initiation and progression. With the advent of somatic cell reprogramming into induced pluripotent stem cells it is now possible to generate patient-derived cells that are able to more accurately model and recapitulate disease. Furthermore, by combining this with recent advances in (epi)genome editing technologies, it is possible to begin to examine the functional consequence of previously nominated genetic variants and infer epigenetic causality from recently identified epigenetic variants. In this review, we explore the role of genetic and epigenetic variation in Alzheimer's disease and how the functional relevance of nominated loci can be investigated using induced pluripotent stem cells and (epi)genome editing techniques.

  20. Opposite variations in maternal and neonatal thyroid function induced by iodine supplementation during pregnancy

    DEFF Research Database (Denmark)

    Nøhr, S B; Laurberg, P

    2000-01-01

    pregnancy, and 95 took no artificial iodine supplementation. Iodine supplementation (+I) induced opposite variations in thyroid function in the mother and the fetus. In +I mothers, TSH was 7.6% lower than in mothers with no supplementation (P ... in the +I group (P caused by opposite shifts in TSH frequency distribution in mothers and neonates. The association between iodine supplementation and high serum TSH in the neonates was further substantiated by an inverse correlation between thyroglobulin and TSH in cord blood...

  1. Spatial variations in vegetation as related to the soil moisture regime over an arid limestone hillside, northern Negev, Israel.

    Science.gov (United States)

    Yair, A; Danin, A

    1980-01-01

    A detailed study of the distribution of plant communities was conducted in an experimental site, located in the arid northern Negev of Israel, where the spatial variation in rainfall, runoff and soil moisture regime are currently being studied. Phytogeographical methods of analysis usually used for studies on a regional scale were applied for a small area extending over 11,325 m 2 of a north-facing hillside. Data obtained indicate that the best water regime and a high diversity of plant species are characteristic of a massive limestone rock unit; whereas worse water regimes characterize densely jointed and thinly bedded limestones. Over slopes, developed in a uniform lithology, whose lower part is composed of a colluvial mantle, a gradual downslope worsening of the soil moisture regime is recorded within the colluvium. These changes are well expressed in the distribution of the plant communities and their phytogeographical affinities along the slopes.

  2. Enlargement of induced variations by combined method of chronic irradiations with callus culture in sugarcane

    International Nuclear Information System (INIS)

    Nagatomi, Shigeki

    1993-01-01

    The present study was conducted to elucidate the effects of gamma ray irradiation and callus culture upon induced variation of the regeneratives. The populations regenerated from young leaf tissue of chronic irradiated plnats grown under a gamma field receiving a total dose of 300 and 100 Gy, showed rather wider variation on quantitative characters than plants from populations of the non-irradiated. This variation extended in both negative and positive directions. Analysis of variance also revealed that variation and heritability in broad sense of most agronomic characters increased significantly among the subclones as the irradiation done rose. Principal component analysis also indicated that the subclones from the irradiated population were more variable than the non-irradiated. Such variation with higher heritability could be transmitted to the following generations by clonal propagation and utilized as genetic sources in mutation breeding. The combined method with chronic irradiation followed by tissue culture is evaluated as an effective method of widening mutation spectrum and increasing mutation frequency in regenerated plants. In addition, this method is valid to improve any crop species which can regenerate plants through callus culture. (author)

  3. UV-induced carbon monoxide emission from sand and living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard

    2012-01-01

    The global burden of carbon monoxide, CO, is rather uncertain. In this paper we address the potential of UV-induced CO emission by terrestrial surfaces. Real-time measurements of [CO] were made with a cavity enhanced laser connected in closed loop to either an ecosystem chamber or a leaf scale...... chamber. Sand and leaves of all examined plant species exhibited emission of CO in response to artificial UV-radiation and the UV-component of natural solar radiation. The UV-induced rate of CO emission exhibited a rather low dependence on temperature, indicating an abiotic process. The emission of CO...... in response to the UV-component of natural solar radiation was also evident at the ecosystem scale. When scaled to the global level, the UV-induced emission of CO by the major types of terrestrial surfaces, living leaves and soil (here represented by sand), amounts up to 28 Tg yr−1. This source has...

  4. 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)

    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

    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

  5. Radiation and chemical mutagen induced somaclonal variations through in vitro organogenesis of cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Muthusamy, Annamalai; Jayabalan, Narayanasamy

    2014-12-01

    The purpose of the investigation was to induce somaclonal variations by gamma rays (GR), ethylmethane sulphonate (EMS) and sodium azide (SA) during in vitro organogenesis of cotton. The shoot tip explants were irradiated with 5-50 Gray (Gy) GR (Cobalt 60), 0.5-5.0 mM EMS and SA separately, and inoculated on Murashige and Skoog (MS) medium fortified with plant growth regulator (PGR) for organogenesis. The plantlets with well-developed root systems were acclimatized and transferred into the experimental field to screen the somaclonal variations during growth and development. The number of somaclonal variations was observed in growth of irradiated/treated shoot tips, multiplication, plantlet regeneration and growth in vitro and ex vitro. The lower doses/concentrations of mutagenic treatments showed significant enhancement in selected agronomical characters and they showed decreased trends with increasing doses/concentrations of mutagenic agents. The results of the present study revealed the influence of lower doses/concentrations of mutagenic treatments on in vitro and ex vitro growth of cotton plantlets and their significant improvement in agronomical characters which needs further imperative stability analysis. The present observations showed the platform to use lower doses/concentrations of mutagenic agents to induce variability for enhanced agronomical characters, resistant and tolerant cotton varieties.

  6. A model for the effect of submerged aquatic vegetation on turbulence induced by an oscillating grid

    Science.gov (United States)

    Pujol, Dolors; Colomer, Jordi; Serra, Teresa; Casamitjana, Xavier

    2012-12-01

    The aim of this study is to model, under controlled laboratory conditions, the effect of submerged aquatic vegetation (SAV) on turbulence generated in a water column by an oscillating grid turbulence (OGT). Velocity profiles have been measured by an acoustic Doppler velocimeter (MicroADV). Experimental conditions are analysed in two canopy models (rigid and semi-rigid), using nine plant-to-plant distances (ppd), three stem diameters (d), four types of natural SAV (Cladium mariscus, Potamogeton nodosus, Myriophyllum verticillatum and Ruppia maritima) and two oscillation grid frequencies (f). To quantify this response, we have developed a non-dimensional model, with a specific turbulent kinetic energy (TKE), f, stroke (s), d, ppd, distance from the virtual origin to the measurement (zm) and space between grid bars (M). The experimental data show that, at zm/zc 1, TKE decreases faster with zm and scales to the model variables according to TKE/(f·s)∝(·(. Therefore, at zm/zc > 1 the TKE is affected by the geometric characteristics of the plants (both diameter and plant-to-plant distance), an effect called sheltering. Results from semi-rigid canopies and natural SAV are found to scale with the non-dimensional model proposed for rigid canopies. We also discuss the practical implications for field conditions (wind and natural SAV).

  7. Application of radiation induced mutations in the improvement of vegetatively propagated crops

    International Nuclear Information System (INIS)

    Mohan Jain, S.

    2009-01-01

    Full text: The NOBEL PEACE PRIZE, 2005, award to the International Atomic Energy Agency (IAEA) is a recognition to the contributions of nuclear technique applications, in a tough face off with plant genetic engineering, in sustainable food production, improvement of nutrition balance, and food security. Nuclear technology is effective in generating genetic variability, selection of useful mutants and multiplication in large numbers. A wide range of mutants of various vegetatively propagated crops have been isolated (www.iaea.org). In vitro plant regeneration is very much genotypic dependent, type of explants; culture medium, plant growth regulators etc. Somatic embryogenesis is an ideal system for the selection and multiplication of mutants and also would save time to dissociate chimeras. The role of molecular tools has become very crucial in understanding the molecular basis of differentiation and genetic variability; gene identification, isolation, and transfer. The new gene discovery with reverse and forward genetics will open the way for developing functional genomic plant breeding. There is no opposition from the consumers to consume food products derived from mutants, unlike strong opposition to the consumption of genetically modified (GM) food. Moreover, bio-safety regulations are not applied to mutants, however, strictly adhere to GM food. Tomorrow's agriculture will be under tremendous pressure for feeding the world's population in the face of climatic changes, salt and drought stresses, and biotic stresses; and mutagenesis would be the answer

  8. Sucrose-induced anthocyanin accumulation in vegetative tissue of Petunia plants requires anthocyanin regulatory transcription factors.

    Science.gov (United States)

    Ai, Trinh Ngoc; Naing, Aung Htay; Arun, Muthukrishnan; Lim, Sun-Hyung; Kim, Chang Kil

    2016-11-01

    The effects of three different sucrose concentrations on plant growth and anthocyanin accumulation were examined in non-transgenic (NT) and transgenic (T 2 ) specimens of the Petunia hybrida cultivar 'Mirage rose' that carried the anthocyanin regulatory transcription factors B-Peru+mPAP1 or RsMYB1. Anthocyanin accumulation was not observed in NT plants in any treatments, whereas a range of anthocyanin accumulation was observed in transgenic plants. The anthocyanin content detected in transgenic plants expressing the anthocyanin regulatory transcription factors (B-Peru+mPAP1 or RsMYB1) was higher than that in NT plants. In addition, increasing sucrose concentration strongly enhanced anthocyanin content as shown by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, wherein increased concentrations of sucrose enhanced transcript levels of the transcription factors that are responsible for the induction of biosynthetic genes involved in anthocyanin synthesis; this pattern was not observed in NT plants. In addition, sucrose affected plant growth, although the effects were different between NT and transgenic plants. Taken together, the application of sucrose could enhance anthocyanin production in vegetative tissue of transgenic Petunia carrying anthocyanin regulatory transcription factors, and this study provides insights about interactive effects of sucrose and transcription factors in anthocyanin biosynthesis in the transgenic plant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Induced variation for Pelshenke value and caryopsis weight in bread wheat

    International Nuclear Information System (INIS)

    Siddiqui, K.A.; Arain, M.A.

    1986-01-01

    The paper presents the evidence of induced mutations for Pelshenke value and caryopsis weight. M 2 population of bread wheat (Triticum aestivum L.) variety Pak 70 derived from different doses of gamma rays (100, 150, 200 Gy) and fast neutrons (300, 450, 600 Rads) were screened. The coefficient of variation for Pelshenke value was considerably higher in Nf 450 Rads and 100 Gy gamma ray treatments in comparison with the untreated control. Gamma ray treatments were more effective than fast neutrons in increasing the caryopsis weight. Selection strategy based on highly heritable traits can result in breeding varieties with high yield and improved baking quality. (author)

  10. Leakage flow-induced vibrations for variations of a tube-in-tube slip joint

    International Nuclear Information System (INIS)

    Mulcahy, T.M.

    1986-01-01

    Variations in the design of a specific slip joint separating two cantilevered, telescoping tubes conveying water were studied to determine their effect upon the leakage flow-induced vibration self-excitation mechanism known to exist for the original slip joint geometry. The important parameters controlling the self-excitation mechanism were identified, which, along with previous results, allowed the determination of a comprehensive set of design rules to avoid unstable vibrations. This was possible even though a new self-excitation mechanism was found when the engagement of the two tubes was small. 9 refs

  11. Reconstructed Solar-Induced Fluorescence: A Machine Learning Vegetation Product Based on MODIS Surface Reflectance to Reproduce GOME-2 Solar-Induced Fluorescence

    Science.gov (United States)

    Gentine, P.; Alemohammad, S. H.

    2018-04-01

    Solar-induced fluorescence (SIF) observations from space have resulted in major advancements in estimating gross primary productivity (GPP). However, current SIF observations remain spatially coarse, infrequent, and noisy. Here we develop a machine learning approach using surface reflectances from Moderate Resolution Imaging Spectroradiometer (MODIS) channels to reproduce SIF normalized by clear sky surface irradiance from the Global Ozone Monitoring Experiment-2 (GOME-2). The resulting product is a proxy for ecosystem photosynthetically active radiation absorbed by chlorophyll (fAPARCh). Multiplying this new product with a MODIS estimate of photosynthetically active radiation provides a new MODIS-only reconstruction of SIF called Reconstructed SIF (RSIF). RSIF exhibits much higher seasonal and interannual correlation than the original SIF when compared with eddy covariance estimates of GPP and two reference global GPP products, especially in dry and cold regions. RSIF also reproduces intense productivity regions such as the U.S. Corn Belt contrary to typical vegetation indices and similarly to SIF.

  12. Tissue culture-induced genetic and epigenetic variation in triticale (× Triticosecale spp. Wittmack ex A. Camus 1927) regenerants.

    Science.gov (United States)

    Machczyńska, Joanna; Zimny, Janusz; Bednarek, Piotr Tomasz

    2015-10-01

    Plant regeneration via in vitro culture can induce genetic and epigenetic variation; however, the extent of such changes in triticale is not yet understood. In the present study, metAFLP, a variation of methylation-sensitive amplified fragment length polymorphism analysis, was used to investigate tissue culture-induced variation in triticale regenerants derived from four distinct genotypes using androgenesis and somatic embryogenesis. The metAFLP technique enabled identification of both sequence and DNA methylation pattern changes in a single experiment. Moreover, it was possible to quantify subtle effects such as sequence variation, demethylation, and de novo methylation, which affected 19, 5.5, 4.5% of sites, respectively. Comparison of variation in different genotypes and with different in vitro regeneration approaches demonstrated that both the culture technique and genetic background of donor plants affected tissue culture-induced variation. The results showed that the metAFLP approach could be used for quantification of tissue culture-induced variation and provided direct evidence that in vitro plant regeneration could cause genetic and epigenetic variation.

  13. Effects of an Encapsulated Fruit and Vegetable Juice Concentrate on Obesity-Induced Systemic Inflammation: A Randomised Controlled Trial

    Directory of Open Access Journals (Sweden)

    Evan J. Williams

    2017-02-01

    Full Text Available Phytochemicals from fruit and vegetables reduce systemic inflammation. This study examined the effects of an encapsulated fruit and vegetable (F&V juice concentrate on systemic inflammation and other risk factors for chronic disease in overweight and obese adults. A double-blinded, parallel, randomized placebo-controlled trial was conducted in 56 adults aged ≥40 years with a body mass index (BMI ≥28 kg/m2. Before and after eight weeks daily treatment with six capsules of F&V juice concentrate or placebo, peripheral blood gene expression (microarray, quantitative polymerase chain reaction (qPCR, plasma tumour necrosis factor (TNFα (enzyme-linked immunosorbent assay (ELISA, body composition (Dual-energy X-ray absorptiometry (DEXA and lipid profiles were assessed. Following consumption of juice concentrate, total cholesterol, low-density lipoprotein (LDL cholesterol and plasma TNFα decreased and total lean mass increased, while there was no change in the placebo group. In subjects with high systemic inflammation at baseline (serum C-reactive protein (CRP ≥3.0 mg/mL who were supplemented with the F&V juice concentrate (n = 16, these effects were greater, with decreased total cholesterol, LDL cholesterol and plasma TNFα and increased total lean mass; plasma CRP was unchanged by the F&V juice concentrate following both analyses. The expression of several genes involved in lipogenesis, the nuclear factor-κB (NF-κB and 5′ adenosine monophosphate-activated protein kinase (AMPK signalling pathways was altered, including phosphomevalonate kinase (PMVK, zinc finger AN1-type containing 5 (ZFAND5 and calcium binding protein 39 (CAB39, respectively. Therefore, F&V juice concentrate improves the metabolic profile, by reducing systemic inflammation and blood lipid profiles and, thus, may be useful in reducing the risk of obesity-induced chronic disease.

  14. Integration of satellite-induced fluorescence and vegetation optical depth to improve the retrieval of land evaporation

    Science.gov (United States)

    Pagán, B. R.; Martens, B.; Maes, W. H.; Miralles, D. G.

    2017-12-01

    Global satellite-based data sets of land evaporation overcome limitations in coverage of in situ measurements while retaining some observational nature. Although their potential for real world applications are promising, their value during dry conditions is still poorly understood. Most evaporation retrieval algorithms are not directly sensitive to soil moisture. An exception is the Global Land Evaporation Amsterdam Model (GLEAM), which uses satellite surface soil moisture and precipitation to account for land water availability. The existing methodology may greatly benefit from the optimal integration of novel observations of the land surface. Microwave vegetation optical depth (VOD) and near-infrared solar-induced fluorescence (SIF) are expected to reflect different aspects of evaporative stress. While the former is considered to be a proxy of vegetation water content, the latter is indicative of the activity of photosynthetic machinery. As stomata regulate both photosynthesis and transpiration, we expect a relationship between SIF and transpiration. An important motivation to incorporate observations in land evaporation calculations is that plant transpiration - usually the largest component of the flux - is extremely challenging to model due to species-dependent responses to drought. Here we present an innovative integration of VOD and SIF into the GLEAM evaporative stress function. VOD is utilized as a measurement of isohydricity to improve the representation of species specific drought responses. SIF is used for transpiration modelling, a novel application, and standardized by incoming solar radiation to better account for radiation-limited periods. Results are validated with global FLUXNET and International Soil Moisture Network data and demonstrate that the incorporation of VOD and SIF can yield accurate estimates of transpiration over large-scales, which are essential to further understand ecosystem-atmosphere feedbacks and the response of terrestrial

  15. Elucidating the role of vegetation in the initiation of rainfall-induced shallow landslides: Insights from an extreme rainfall event in the Colorado Front Range

    Science.gov (United States)

    McGuire, Luke; Rengers, Francis K.; Kean, Jason W.; Coe, Jeffrey A.; Mirus, Benjamin B.; Baum, Rex L.; Godt, Jonathan W.

    2016-01-01

    More than 1100 debris flows were mobilized from shallow landslides during a rainstorm from 9 to 13 September 2013 in the Colorado Front Range, with the vast majority initiating on sparsely vegetated, south facing terrain. To investigate the physical processes responsible for the observed aspect control, we made measurements of soil properties on a densely forested north facing hillslope and a grassland-dominated south facing hillslope in the Colorado Front Range and performed numerical modeling of transient changes in soil pore water pressure throughout the rainstorm. Using the numerical model, we quantitatively assessed interactions among vegetation, rainfall interception, subsurface hydrology, and slope stability. Results suggest that apparent cohesion supplied by roots was responsible for the observed connection between debris flow initiation and slope aspect. Results suggest that future climate-driven modifications to forest structure could substantially influence landslide hazards throughout the Front Range and similar water-limited environments where vegetation communities may be more susceptible to small variations in climate.

  16. Day-night variation in heart rate variability changes induced by endotoxaemia in healthy volunteers.

    Science.gov (United States)

    Alamili, M; Rosenberg, J; Gögenur, I

    2015-04-01

    Morbidity and mortality in response to sepsis may be dependent on clock time for the initiation of sepsis. Endotoxaemia, an experimental model for systemic inflammation, induces alterations in sympatico-vagal balance in the autonomic nervous system (ANS). The activity of sympathetic and parasympathetic activity can be estimated by measuring heart rate variability (HRV). Based on the intimate link between ANS and the inflammatory response, we hypothesized, that HRV changes seen during endotoxaemia would be different based on time of the day the endotoxaemia is initiated. We investigated day/night variation in endotoxaemia-induced changes in HRV. A randomized, crossover study with 12 healthy men (age 18-31) was conducted. Endotoxaemia were induced by lipopolysaccharide (LPS) endotoxin 0.3 ng/kg b.w. in two visits (day visit and night visit). At the day visit, endotoxaemia were induced at 12:00 h, and at the night visit it was induced at 24:00 h. Holter recordings were started 1 h before administration of LPS, and continued for 10 h. Time-domain and frequency-domain parameters of HRV were analysed. A total of nine persons finished the study with valid recordings. Endotoxaemia at both night and day resulted in a significant depression in HRV parameters high-frequency power (HF), low-frequency power (LF), standard deviation of normal-to-normal (NN) intervals, root mean square of successive differences and proportion of NN50 divided by total number of NNs (Pnight-time endotoxaemia, a more pronounced depression of LF, HF and SDNN (Pday-time endotoxaemia. Endotoxaemia induced changes in HRV exhibit a day-night difference. This difference may have clinical consequences in patients with sepsis. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  17. Variations in sea surface roughness induced by the 2004 Sumatra-Andaman tsunami

    Directory of Open Access Journals (Sweden)

    O. A. Godin

    2009-07-01

    Full Text Available Observations of tsunamis away from shore are critically important for improving early warning systems and understanding of tsunami generation and propagation. Tsunamis are difficult to detect and measure in the open ocean because the wave amplitude there is much smaller than it is close to shore. Currently, tsunami observations in deep water rely on measurements of variations in the sea surface height or bottom pressure. Here we demonstrate that there exists a different observable, specifically, ocean surface roughness, which can be used to reveal tsunamis away from shore. The first detailed measurements of the tsunami effect on sea surface height and radar backscattering strength in the open ocean were obtained from satellite altimeters during passage of the 2004 Sumatra-Andaman tsunami. Through statistical analyses of satellite altimeter observations, we show that the Sumatra-Andaman tsunami effected distinct, detectable changes in sea surface roughness. The magnitude and spatial structure of the observed variations in radar backscattering strength are consistent with hydrodynamic models predicting variations in the near-surface wind across the tsunami wave front. Tsunami-induced changes in sea surface roughness can be potentially used for early tsunami detection by orbiting microwave radars and radiometers, which have broad surface coverage across the satellite ground track.

  18. Endogenous abscisic acid as a key switch for natural variation in flooding-induced shoot elongation.

    Science.gov (United States)

    Chen, Xin; Pierik, Ronald; Peeters, Anton J M; Poorter, Hendrik; Visser, Eric J W; Huber, Heidrun; de Kroon, Hans; Voesenek, Laurentius A C J

    2010-10-01

    Elongation of leaves and stem is a key trait for survival of terrestrial plants during shallow but prolonged floods that completely submerge the shoot. However, natural floods at different locations vary strongly in duration and depth, and, therefore, populations from these locations are subjected to different selection pressure, leading to intraspecific variation. Here, we identified the signal transduction component that causes response variation in shoot elongation among two accessions of the wetland plant Rumex palustris. These accessions differed 2-fold in petiole elongation rates upon submergence, with fast elongation found in a population from a river floodplain and slow elongation in plants from a lake bank. Fast petiole elongation under water consumes carbohydrates and depends on the (inter)action of the plant hormones ethylene, abscisic acid, and gibberellic acid. We found that carbohydrate levels and dynamics in shoots did not differ between the fast and slow elongating plants, but that the level of ethylene-regulated abscisic acid in petioles, and hence gibberellic acid responsiveness of these petioles explained the difference in shoot elongation upon submergence. Since this is the exact signal transduction level that also explains the variation in flooding-induced shoot elongation among plant species (namely, R. palustris and Rumex acetosa), we suggest that natural selection results in similar modification of regulatory pathways within and between species.

  19. Decadal Variation of Precipitation in Saudi Arabia induced by Agricultural Irrigation

    Science.gov (United States)

    Lo, M. H.; Wey, H. W.; Wada, Y.; IM, E. S.; Chien, R. Y.; Wu, R. J.

    2017-12-01

    Decadal variation of wet-season precipitation has been found in the arid region of central Saudi Arabia. 1980s has been a rather wet decade compared with the decades before. Previous studies have mentioned that the irrigation moisture may contribute to the precipitation anomalies in Saudi Arabia. In the current study, we show from observational data that the contribution of the variation comes mostly from February to May. As the irrigation is a localized forcing, we therefore use the Weather Research and Forecasting (WRF) Model to simulate the response of the land-atmosphere interaction to the wet soil moisture resulted from additional irrigation moisture supply. Preliminary result shows in the irrigated simulation that precipitation in central Saudi Arabia is enhanced, indicating the possible link between irrigation expansion in the 1980s and the decadal precipitation variation over central Saudi Arabia. We propose it is the anomalous convergence induced by irrigation as well as additional moisture that contribute to the enhanced precipitation over heavily irrigation region in the central Saudi Arabian. In addition, analysis on the daily precipitation from the WRF outputs indicates that positive rainfall anomalies tend to happen when there is rainfall originally; that is, irrigation enhances rainfall but not creates rainfall.

  20. The effect of cooking on the phytochemical content of vegetables

    NARCIS (Netherlands)

    Palermo, M.; Pellegrini, N.; Fogliano, V.

    2014-01-01

    Cooking induces many chemical and physical modifications in foods; among these the phytochemical content can change. Many authors have studied variations in vegetable nutrients after cooking, and great variability in the data has been reported. In this review more than 100 articles from indexed

  1. Portable detection system of vegetable oils based on laser induced fluorescence

    Science.gov (United States)

    Zhu, Li; Zhang, Yinchao; Chen, Siying; Chen, He; Guo, Pan; Mu, Taotao

    2015-11-01

    Food safety, especially edible oils, has attracted more and more attention recently. Many methods and instruments have emerged to detect the edible oils, which include oils classification and adulteration. It is well known than the adulteration is based on classification. Then, in this paper, a portable detection system, based on laser induced fluorescence, is proposed and designed to classify the various edible oils, including (olive, rapeseed, walnut, peanut, linseed, sunflower, corn oils). 532 nm laser modules are used in this equipment. Then, all the components are assembled into a module (100*100*25mm). A total of 700 sets of fluorescence data (100 sets of each type oil) are collected. In order to classify different edible oils, principle components analysis and support vector machine have been employed in the data analysis. The training set consisted of 560 sets of data (80 sets of each oil) and the test set consisted of 140 sets of data (20 sets of each oil). The recognition rate is up to 99%, which demonstrates the reliability of this potable system. With nonintrusive and no sample preparation characteristic, the potable system can be effectively applied for food detection.

  2. Disentangling drought-induced variation in ecosystem and soil respiration using stable carbon isotopes.

    Science.gov (United States)

    Unger, Stephan; Máguas, Cristina; Pereira, João S; Aires, Luis M; David, Teresa S; Werner, Christiane

    2010-08-01

    Combining C flux measurements with information on their isotopic composition can yield a process-based understanding of ecosystem C dynamics. We studied the variations in both respiratory fluxes and their stable C isotopic compositions (delta(13)C) for all major components (trees, understory, roots and soil microorganisms) in a Mediterranean oak savannah during a period with increasing drought. We found large drought-induced and diurnal dynamics in isotopic compositions of soil, root and foliage respiration (delta(13)C(res)). Soil respiration was the largest contributor to ecosystem respiration (R (eco)), exhibiting a depleted isotopic signature and no marked variations with increasing drought, similar to ecosystem respired delta(13)CO(2), providing evidence for a stable C-source and minor influence of recent photosynthate from plants. Short-term and diurnal variations in delta(13)C(res) of foliage and roots (up to 8 and 4 per thousand, respectively) were in agreement with: (1) recent hypotheses on post-photosynthetic fractionation processes, (2) substrate changes with decreasing assimilation rates in combination with increased respiratory demand, and (3) decreased phosphoenolpyruvate carboxylase activity in drying roots, while altered photosynthetic discrimination was not responsible for the observed changes in delta(13)C(res). We applied a flux-based and an isotopic flux-based mass balance, yielding good agreement at the soil scale, while the isotopic mass balance at the ecosystem scale was not conserved. This was mainly caused by uncertainties in Keeling plot intercepts at the ecosystem scale due to small CO(2) gradients and large differences in delta(13)C(res) of the different component fluxes. Overall, stable isotopes provided valuable new insights into the drought-related variations of ecosystem C dynamics, encouraging future studies but also highlighting the need of improved methodology to disentangle short-term dynamics of isotopic composition of R (eco).

  3. Relation cellular- molecular between serum IL10 levels and hyperalgesia variation in adjuvant- induced arthritis

    Directory of Open Access Journals (Sweden)

    Zenab Akhtari

    2015-01-01

    Full Text Available Background: Regarding to the important anti-inflammatory role of IL10 during inflammation process and hyperalgesia and edema variation during CFA-induced arthritis and also the increase of Spinal mu opioid receptor (mOR expression, in this study researchers investigate the role of serum IL10 level on mOR expression and edema and hyperalgesia variation during different stages of Complete Freund`s Adjuvant (CFA - induced arthritis in male Wistar rats. Materials and Methods: Mono-arthritis was induced by CFA and inflammatory symptoms (hyperalgesia and edema were assessed on 0, 3, 7, 14th and 21st days of study. Anti-IL10 was administered during the 21 days of study in different experimental groups. mOR expression were detected by western blotting on 0, 3,7, 14th and 21st days of study. Data was analyzed by SPSS statistical software version 19 with using one way ANOVA (post hoc Tokey's. Results: Our results showed that anti-IL10 administration in AA group (Adjuvant Arthritis caused an increase in the paw volume and hyperalgesia until 21st of study. Our study stated that there were no significant differences in spinal mOR expression between AA and AA+anti-IL10rats. Conclusion: Our study confirmed that anti-IL10administration caused to hyperalgesia and edema during AA inflammation. Also these findings suggested that mOR expression increased in chronic phase of AA inflammation, however an increase in the level of spinal mu opioid receptor (mOR expression during AA inflammation is not mediated directly via the effect of serum IL-10.

  4. Genetic and epigenetic variations induced by wheat-rye 2R and 5R monosomic addition lines.

    Science.gov (United States)

    Fu, Shulan; Sun, Chuanfei; Yang, Manyu; Fei, Yunyan; Tan, Feiqun; Yan, Benju; Ren, Zhenglong; Tang, Zongxiang

    2013-01-01

    Monosomic alien addition lines (MAALs) can easily induce structural variation of chromosomes and have been used in crop breeding; however, it is unclear whether MAALs will induce drastic genetic and epigenetic alterations. In the present study, wheat-rye 2R and 5R MAALs together with their selfed progeny and parental common wheat were investigated through amplified fragment length polymorphism (AFLP) and methylation-sensitive amplification polymorphism (MSAP) analyses. The MAALs in different generations displayed different genetic variations. Some progeny that only contained 42 wheat chromosomes showed great genetic/epigenetic alterations. Cryptic rye chromatin has introgressed into the wheat genome. However, one of the progeny that contained cryptic rye chromatin did not display outstanding genetic/epigenetic variation. 78 and 49 sequences were cloned from changed AFLP and MSAP bands, respectively. Blastn search indicated that almost half of them showed no significant similarity to known sequences. Retrotransposons were mainly involved in genetic and epigenetic variations. Genetic variations basically affected Gypsy-like retrotransposons, whereas epigenetic alterations affected Copia-like and Gypsy-like retrotransposons equally. Genetic and epigenetic variations seldom affected low-copy coding DNA sequences. The results in the present study provided direct evidence to illustrate that monosomic wheat-rye addition lines could induce different and drastic genetic/epigenetic variations and these variations might not be caused by introgression of rye chromatins into wheat. Therefore, MAALs may be directly used as an effective means to broaden the genetic diversity of common wheat.

  5. Mass-induced [|#8#|]Sea Level Variations in the Red Sea from Satellite Altimetry and GRACE

    Science.gov (United States)

    Feng, W.; Lemoine, J.; Zhong, M.; Hsu, H.

    2011-12-01

    We have analyzed mass-induced sea level variations (SLVs) in the Red Sea from steric-corrected altimetry and GRACE between January 2003 and December 2010. The steric component of SLVs in the Red Sea calculated from climatological temperature and salinity data is relatively small and anti-phase with the mass-induced SLV. The total SLV in the Red Sea is mainly driven by the mass-induced SLV, which increases in winter when the Red Sea gains the water mass from the Gulf of Aden and vice versa in summer. Spatial and temporal patterns of mass-induced SLVs in the Red Sea from steric-corrected altimetry agree very well with GRACE observations. Both of two independent observations show high annual amplitude in the central Red Sea (>20cm). Total mass-induced SLVs in the Red Sea from two independent observations have similar annual amplitude and phase. One main purpose of our work is to see whether GRGS's ten-day GRACE results can observe intra-seasonal mass change in the Red Sea. The wavelet coherence analysis indicates that GRGS's results show the high correlation with the steric-corrected SLVs on intra-seasonal time scale. The agreement is excellent for all the time-span until 1/3 year period and is patchy between 1/3 and 1/16 year period. Furthermore, water flux estimates from current-meter arrays and moorings show mass gain in winter and mass loss in summer, which is also consistent with altimetry and GRACE.

  6. Heritable Variation in Quinone-Induced Haustorium Development in the Parasitic Plant Triphysaria1

    Science.gov (United States)

    Jamison, Denneal S.; Yoder, John I.

    2001-01-01

    We are using the facultative hemiparasite, Triphysaria, as a model for studying host-parasite signaling in the Scrophulariaceae. Parasitic members of this family form subterranean connections, or haustoria, on neighboring host roots to access host water and nutrients. These parasitic organs develop in response to haustorial-inducing factors contained in host root exudates. A well-characterized inducing factor, 2, 6-dimethoxy-p-benzoquinone (DMBQ), can be used to trigger in vitro haustorium formation in the roots of Triphysaria. We have assayed three species, Triphysaria eriantha (Benth.) Chuang and Heckard, Triphysaria pusilla (Benth.) Chuang and Heckard, and Triphysaria versicolor Fischer and C. Meyer, for haustorium development in response to DMBQ. There were significant differences between the species in their ability to recognize and respond to this quinone. Ninety percent of T. versicolor individuals responded, whereas only 40% of T. pusilla and less than 10% of T. eriantha formed haustoria. Within field collections of self-pollinating T. pusilla, differential responsiveness to DMBQ was seen in distinct maternal families. Assaying haustorium development in subsequent generations of self-pollinated T. pusilla showed that DMBQ responsiveness was heritable. Reciprocal crosses between T. eriantha and T. versicolor demonstrated that DMBQ responsiveness was influenced by maternal factors. These results demonstrate heritable, natural variation in the recognition of a haustorial-inducing factor by a parasitic member of the Scrophulariaceae. PMID:11299366

  7. Fruit, Vegetable and Dietary Carotenoid Intakes Explain Variation in Skin-Color in Young Caucasian Women: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Kristine Pezdirc

    2015-07-01

    Full Text Available Fruit and vegetables contain carotenoid pigments, which accumulate in human skin, contributing to its yellowness. This effect has a beneficial impact on appearance. The aim was to evaluate associations between diet (fruit, vegetable and dietary carotenoid intakes and skin color in young women. Ninety-one Caucasian women (Median and Interquartile Range (IQR age 22.1 (18.1–29.1 years, BMI 22.9 (18.5–31.9 kg/m2 were recruited from the Hunter region (Australia. Fruit, vegetable and dietary carotenoid intakes were estimated by a validated food frequency questionnaire. Skin color was measured at nine body locations (sun exposed and unexposed sites using spectrophotometry. Multiple linear regression was used to assess the relationship between fruit and vegetable intakes and skin yellowness adjusting for known confounders. Higher combined fruit and vegetable intakes (β = 0.8, p = 0.017 were associated with higher overall skin yellowness values. Higher fruit combined fruit and vegetable intakes (β = 1.0, p = 0.004 were associated with increased unexposed skin yellowness. Combined fruit and vegetables plus dietary carotenoid intakes contribute to skin yellowness in young Caucasian women. Evaluation of interventions using improvements in appearance as an incentive for increasing fruit and vegetable consumption in young women is warranted.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  9. Investigation on seasonal variation of thermal-induced strain in flexible pavements based on field and laboratory measurements

    Directory of Open Access Journals (Sweden)

    Simita Biswas

    2016-09-01

    Full Text Available Pavement temperature variation has a large influence on the structural response of flexible pavements. Daily and seasonal temperature fluctuation causes expansion and contraction of pavement material, which then leads to the generation of thermal strain. In this study, field observation and laboratory tests were conducted to investigate seasonal variation of thermal-induced strain in flexible pavement. Field observations were conducted at the Integrated Road Research Facility (IRRF’s test road in Edmonton, Alberta, Canada, which is fully equipped with structural and environmental monitoring instruments. The main objective of the field study was to compare the variation of thermal-induced strain in warm and cold seasons. Field results indicated that thermal-induced strain is 1.4–2.0 times greater in cold seasons than in warm seasons following the same pavement temperature variations; however, strain generation rate was greater in warm seasons. Laboratory testing of asphalt slab and cylindrical samples produced comparable ratios. Moreover, field observation and laboratory testing showed a similar trend of temperature and thermal strain variations. Keywords: Thermal-induced strain, Asphalt strain gauge, Field observation, Flexible pavement, Laboratory testing, Seasonal variation

  10. Structural variations of chromosome 1 R from rye cultivar Jingzhouheimai induced by irradiation

    International Nuclear Information System (INIS)

    Wang Conglei; Zhuang Lifang; Qi Zengjun

    2012-01-01

    Irradiated with 60 Co γ-rays (12 Gy), the pollen of wheat landrace Huixianhong-Secale cereal cv. Jingzhouheimai DA1R was pollinated to the emasculated spikes of Huixianhong. Analyzed with genomic in situ hybridization GISH using gDNA of rye cv. Jingzhouheimai as a probe, four plants with reciprocal translocation, four plants with large segmental translocation and one plant with distal segmental translocation, one plant with one telocentric chromosome were identified from 33 M 1 seeds. The results showed that the translocation frequency was 30.30% and of the total 11 breakage-fusion events, 1 involved centric regions and 10 involved interstitial regions. The experiment showed that pollen irradiation was an effective method to induce wheat alien chromosomal structural variations which could effectively by used in deletion mapping, chromosomal location of important agronomic genes and development of small segmental translocations with target genes. (authors)

  11. Inducible nitric oxide synthase (iNOS) regulatory region variation in non-human primates.

    Science.gov (United States)

    Roodgar, Morteza; Ross, Cody T; Kenyon, Nicholas J; Marcelino, Gretchen; Smith, David Glenn

    2015-04-01

    Inducible nitric oxide synthase (iNOS) is an enzyme that plays a key role in intracellular immune response against respiratory infections. Since various species of nonhuman primates exhibit different levels of susceptibility to infectious respiratory diseases, and since variation in regulatory regions of genes is thought to play a key role in expression levels of genes, two candidate regulatory regions of iNOS were mapped, sequenced, and compared across five species of nonhuman primates: African green monkeys (Chlorocebus sabaeus), pig-tailed macaques (Macaca nemestrina), cynomolgus macaques (Macaca fascicularis), Indian rhesus macaques (Macaca mulatta), and Chinese rhesus macaques (M. mulatta). In addition, we conducted an in silico analysis of the transcription factor binding sites associated with genetic variation in these two candidate regulatory regions across species. We found that only one of the two candidate regions showed strong evidence of involvement in iNOS regulation. Specifically, we found evidence of 13 conserved binding site candidates linked to iNOS regulation: AP-1, C/EBPB, CREB, GATA-1, GATA-3, NF-AT, NF-AT5, NF-κB, KLF4, Oct-1, PEA3, SMAD3, and TCF11. Additionally, we found evidence of interspecies variation in binding sites for several regulatory elements linked to iNOS (GATA-3, GATA-4, KLF6, SRF, STAT-1, STAT-3, OLF-1 and HIF-1) across species, especially in African green monkeys relative to other species. Given the key role of iNOS in respiratory immune response, the findings of this study might help guide the direction of future studies aimed to uncover the molecular mechanisms underlying the increased susceptibility of African green monkeys to several viral and bacterial respiratory infections. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Genetic variation of soybean agronomic characters induced by irradiation of seed

    International Nuclear Information System (INIS)

    He Zhihong; Wang Jinling

    1988-02-01

    Dry seeds of three soybean varieties were irradiated by 60 Co γ ray with dosage of 4.1C/kg. The varieties irradiated were Fengshou No. 10, Donghong 74-403 and Heinong No. 26, and nonirradiated seeds of the corresponding variety was used as a control. The following genetic parameters of the nine agronomic characters were estimated, including genotypic coefficient of variation, genotypic variance, broad sense heritanility and genetic advance expected through selection. Three types of plant in M 2 and M 3 were used for the estimation of these parameters which comprise semisterility (MS), fertility (MF) in M 1 and control (CK). The genetic advance expected through selection was compared with the actual effect of selection for date of maturity, seed weigh per plant and 100 seed wight. The pattern of the genetic variation in the early generations of the induced population was analysed. Problems of selection for main agronomic characters in the early generations, and significance of fertility of M 1 plants for mutation breeding were discussed

  13. Variation of Neisseria gonorrhoeae lipooligosaccharide directs dendritic cell-induced T helper responses.

    Directory of Open Access Journals (Sweden)

    Sandra J van Vliet

    2009-10-01

    Full Text Available Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4(+ T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival.

  14. Seasonally asymmetric enhancement of northern vegetation productivity

    Science.gov (United States)

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  15. RNA-Mediated cis Regulation in Acinetobacter baumannii Modulates Stress-Induced Phenotypic Variation.

    Science.gov (United States)

    Ching, Carly; Gozzi, Kevin; Heinemann, Björn; Chai, Yunrong; Godoy, Veronica G

    2017-06-01

    In the nosocomial opportunistic pathogen Acinetobacter baumannii , RecA-dependent mutagenesis, which causes antibiotic resistance acquisition, is linked to the DNA damage response (DDR). Notably, unlike the Escherichia coli paradigm, recA and DDR gene expression in A. baumannii is bimodal. Namely, there is phenotypic variation upon DNA damage, which may provide a bet-hedging strategy for survival. Thus, understanding recA gene regulation is key to elucidate the yet unknown DDR regulation in A. baumannii Here, we identify a structured 5' untranslated region (UTR) in the recA transcript which serves as a cis -regulatory element. We show that a predicted stem-loop structure in this 5' UTR affects mRNA half-life and underlies bimodal gene expression and thus phenotypic variation in response to ciprofloxacin treatment. We furthermore show that the stem-loop structure of the recA 5' UTR influences intracellular RecA protein levels and, in vivo , impairing the formation of the stem-loop structure of the recA 5' UTR lowers cell survival of UV treatment and decreases rifampin resistance acquisition from DNA damage-induced mutagenesis. We hypothesize that the 5' UTR allows for stable recA transcripts during stress, including antibiotic treatment, enabling cells to maintain suitable RecA levels for survival. This innovative strategy to regulate the DDR in A. baumannii may contribute to its success as a pathogen. IMPORTANCE Acinetobacter baumannii is an opportunistic pathogen quickly gaining antibiotic resistances. Mutagenesis and antibiotic resistance acquisition are linked to the DNA damage response (DDR). However, how the DDR is regulated in A. baumannii remains unknown, since unlike most bacteria, A. baumannii does not follow the regulation of the Escherichia coli paradigm. In this study, we have started to uncover the mechanisms regulating the novel A. baumannii DDR. We have found that a cis -acting 5' UTR regulates recA transcript stability, RecA protein levels, and DNA

  16. Application of Method of Variation to Analyze and Predict Human Induced Modifications of Water Resource Systems

    Science.gov (United States)

    Dessu, S. B.; Melesse, A. M.; Mahadev, B.; McClain, M.

    2010-12-01

    Water resource systems have often used gravitational surface and subsurface flows because of their practicality in hydrological modeling and prediction. Activities such as inter/intra-basin water transfer, the use of small pumps and the construction of micro-ponds challenge the tradition of natural rivers as water resource management unit. On the contrary, precipitation is barely affected by topography and plot harvesting in wet regions can be more manageable than diverting from rivers. Therefore, it is indicative to attend to systems where precipitation drives the dynamics while the internal mechanics constitutes spectrum of human activity and decision in a network of plots. The trade-in volume and path of harvested precipitation depends on water balance, energy balance and the kinematics of supply and demand. Method of variation can be used to understand and predict the implication of local excess precipitation harvest and exchange on the natural water system. A system model was developed using the variational form of Euler-Bernoulli’s equation for the Kenyan Mara River basin. Satellite derived digital elevation models, precipitation estimates, and surface properties such as fractional impervious surface area, are used to estimate the available water resource. Four management conditions are imposed in the model: gravitational flow, open water extraction and high water use investment at upstream and downstream respectively. According to the model, the first management maintains the basin status quo while the open source management could induce externality. The high water market at the upstream in the third management offers more than 50% of the basin-wide total revenue to the upper third section of the basin thus may promote more harvesting. The open source and upstream exploitation suggest potential drop of water availability to downstream. The model exposed the latent potential of economic gradient to reconfigure the flow network along the direction where the

  17. Spatial variation in automated burst suppression detection in pharmacologically induced coma.

    Science.gov (United States)

    An, Jingzhi; Jonnalagadda, Durga; Moura, Valdery; Purdon, Patrick L; Brown, Emery N; Westover, M Brandon

    2015-01-01

    Burst suppression is actively studied as a control signal to guide anesthetic dosing in patients undergoing medically induced coma. The ability to automatically identify periods of EEG suppression and compactly summarize the depth of coma using the burst suppression probability (BSP) is crucial to effective and safe monitoring and control of medical coma. Current literature however does not explicitly account for the potential variation in burst suppression parameters across different scalp locations. In this study we analyzed standard 19-channel EEG recordings from 8 patients with refractory status epilepticus who underwent pharmacologically induced burst suppression as medical treatment for refractory seizures. We found that although burst suppression is generally considered a global phenomenon, BSP obtained using a previously validated algorithm varies systematically across different channels. A global representation of information from individual channels is proposed that takes into account the burst suppression characteristics recorded at multiple electrodes. BSP computed from this representative burst suppression pattern may be more resilient to noise and a better representation of the brain state of patients. Multichannel data integration may enhance the reliability of estimates of the depth of medical coma.

  18. Induced chlorophyll variation in pineapple c v. 'queen' by gamma irradiation (60Cobalt)

    International Nuclear Information System (INIS)

    Valencia, Lolita DC.

    2012-01-01

    Irradiation using gamma rays ( 60 Cobalt) coupled with in vitro culture techniques was undertaken to induce variation or mutation in pineapple. Calli from crown meristem tips of pineapple cv 'Queen' [Ananas comosus (L.) Merr.] were initiated using Murashiege and Skoog's basal meduim supplemented with 10mg/liter 4-amino-3,5,6-trichloro-2-pyrodinecarboxylic acid (Picloram). High percentage of growth and shoot proliferation was observed in basal medium supplemented with 50 μM benzene adenine purine (BAP) and 10 μM gibberrelic acid (GA) after 8 weeks in vitro. Regenerants derived from shoots using different doses of gamma rays (0, 5, 10, 15, 20, 25 and 30 Gy) were evaluated under laboratory conditions. Of the different doses, 15 Gy produced the most variegation in young shoots (chlorophyll variants) maintained in vitro. The variants appeared to have yellow and green color combinations of the young leaves of pineapple 'Queen' variety. When transplanted inside the greenhouse, high percentage of plantlets survival was observed, ranging from 90-95%. Of the different irradiation doses, variegation in young leaves was observed at 15, 20, 25 and 30 Gy. Further assessment on the effect of irradiation is currently being unertaken under screen house conditions. The variants produced could serve a basis for selection of ornamental-type pineapple. In addition, protocols developed on the use of in vitro culture techniques could be utilized as a tool for induced mutation breeding in pineapple. (author)

  19. Noise-driven cooperative dynamics between vegetation and topography in riparian zones

    Science.gov (United States)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca

    2016-04-01

    Riparian ecosystems exhibit complex biotic and abiotic dynamics, where the triad vegetation-sediments-stream determines the eco-geomorphological features of the river landscape. Random fluctuations of the water stage are a key trait of this triad, and a number of behaviors of the fluvial environment can be understood only taking into consideration the role of noise. In fact, in a given plot, vegetation biomass can grow (if the stage is below the plot elevation) or decay (if the stage is above the plot elevation). As a result, biomass exhibits significant temporal variations. In this framework, the capability of vegetation to alter the transect topography (namely, the plot elevation) is crucial. Vegetation can increase the plot elevation by a number of mechanisms (trapping of water- and wind-transported sediment particles, production of organic soil, stabilization of the soil surface). The increment of plot elevation induces the reduction of the plot-specific magnitude, frequency and duration of floods. These more favorable plot-specific hydrological conditions, in turn, induce an increment of biomass. Moreover, the higher the vegetation biomass, the higher the plot elevation increment induced by these mechanisms. In order to elucidate how the stochastically varying water stage and the vegetation-induced topographic alteration shape the bio-morphological characteristics of riparian transects, a stochastic model that takes into account the main links between vegetation, sediments and the stream was adopted. In particular, the capability of vegetation to alter the plot topography was emphasized. In modeling such interactions, the minimalistic approach was pursued. The complex vegetation-sediments-stream interactions were modeled by a set of state-depended stochastic eco-hydraulic equations. The probability density function of vegetation biomass was then analytically evaluated in any transect plot. This pdf strongly depends on the vegetation-topography feedback. We

  20. Spaceborne Sun-Induced Vegetation Fluorescence Time Series from 2007 to 2015 Evaluated with Australian Flux Tower Measurements

    Science.gov (United States)

    Sanders, Abram F. J.; Verstraeten, Willem W.; Kooreman, Maurits L.; van Leth, Thomas C.; Beringer, Jason; Joiner, Joanna

    2016-01-01

    A global, monthly averaged time series of Sun-induced Fluorescence (SiF), spanning January 2007 to June 2015, was derived from Metop-A Global Ozone Monitoring Experiment 2 (GOME-2) spectral measurements. Far-red SiF was retrieved using the filling-in of deep solar Fraunhofer lines and atmospheric absorption bands based on the general methodology described by Joiner et al, AMT, 2013. A Principal Component (PC) analysis of spectra over non-vegetated areas was performed to describe the effects of atmospheric absorption. Our implementation (SiF KNMI) is an independent algorithm and differs from the latest implementation of Joiner et al, AMT, 2013 (SiF NASA, v26), because we used desert reference areas for determining PCs (as opposed to cloudy ocean and some desert) and a wider fit window that covers water vapour and oxygen absorption bands (as opposed to only Fraunhofer lines). As a consequence, more PCs were needed (35 as opposed to 12). The two time series (SiF KNMI and SiF NASA, v26) correlate well (overall R of 0.78) except for tropical rain forests. Sensitivity experiments suggest the strong impact of the water vapour absorption band on retrieved SiF values. Furthermore, we evaluated the SiF time series with Gross Primary Productivity (GPP) derived from twelve flux towers in Australia. Correlations for individual towers range from 0.37 to 0.84. They are particularly high for managed biome types. In the de-seasonalized Australian SiF time series, the break of the Millennium Drought during local summer of 2010/2011 is clearly observed.

  1. Angular Normalization of Ground and Satellite Observations of Sun-induced Chlorophyll Fluorescence for Assessing Vegetation Productivity

    Science.gov (United States)

    Chen, J. M.; He, L.; Chou, S.; Ju, W.; Zhang, Y.; Joiner, J.; Liu, J.; Mo, G.

    2017-12-01

    Sun-induced chlorophyll fluorescence (SIF) measured from plant canopies originates mostly from sunlit leaves. Observations of SIF by satellite sensors, such as GOME-2 and GOSAT, are often made over large view zenith angle ranges, causing large changes in the viewed sunlit leaf fraction across the scanning swath. Although observations made by OCO-2 are near nadir, the observed sunlit leaf fraction could still vary greatly due to changes in the solar zenith angle with latitude and time of overpass. To demonstrate the importance of considering the satellite-target-view geometry in using SIF for assessing vegetation productivity, we conducted multi-angle measurements of SIF using a hyperspectral sensor mounted on an automated rotating system over a rice field near Nanjing, China. A method is developed to separate SIF measurements at each angle into sunlit and shaded leaf components, and an angularly normalized canopy-level SIF is obtained as the weighted sum of sunlit and shaded SIF. This normalized SIF is shown to be a much better proxy of GPP of the rice field measured by an eddy covariance system than the unnormalized SIF observations. The same normalization scheme is also applied to the far-red GOME-2 SIF observations on sunny days, and we found that the normalized SIF is better correlated with model-simulated GPP than the original SIF observations. The coefficient of determination (R2) is improved by 0.07±0.04 on global average using the normalization scheme. The most significant improvement in R2 by 0.09±0.04 is found in deciduous broadleaf forests, where the observed sunlit leaf fraction is highly sensitive to solar zenith angle.

  2. SOAP 2.0: a tool to estimate the photometric and radial velocity variations induced by stellar spots and plages

    International Nuclear Information System (INIS)

    Dumusque, X.; Boisse, I.; Santos, N. C.

    2014-01-01

    This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i ≤8 km s –1 . A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star α Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and plages, but also to correct for it when a major active region is dominating the RV variation.

  3. SOAP 2.0: A Tool to Estimate the Photometric and Radial Velocity Variations Induced by Stellar Spots and Plages

    Science.gov (United States)

    Dumusque, X.; Boisse, I.; Santos, N. C.

    2014-12-01

    This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star α Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and plages, but also to correct for it when a major active region is dominating the RV variation. . The work in this paper is based on observations made with the MOST satellite, the HARPS instrument on the ESO 3.6 m telescope at La Silla Observatory (Chile), and the SOPHIE instrument at the Observatoire de Haute Provence (France).

  4. SOAP 2.0: a tool to estimate the photometric and radial velocity variations induced by stellar spots and plages

    Energy Technology Data Exchange (ETDEWEB)

    Dumusque, X. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Boisse, I. [Laboratoire d' Astrophysique de Marseille (UMR 6110), Technopole de Château-Gombert, 38 rue Frédéric Joliot-Curie, F-13388 Marseille Cedex 13 (France); Santos, N. C., E-mail: xdumusque@cfa.harvard.edu [Centro de Astrofìsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2014-12-01

    This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i ≤8 km s{sup –1}. A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star α Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and plages, but also to correct for it when a major active region is dominating the RV variation.

  5. Vegetation and soils

    Science.gov (United States)

    Burke, M.K.; King, S.L.; Eisenbies, M.H.; Gartner, D.

    2000-01-01

    Intro paragraph: Characterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in hypothesis generation about factors influencing community variation, and helps refine models of community structure. Hierarchical classification of communities is particularly useful for showing relationships among samples (Gauche 1982).

  6. Vegetation Changes along the Qinghai-Tibet Plateau Engineering Corridor Since 2000 Induced by Climate Change and Human Activities

    Directory of Open Access Journals (Sweden)

    Yi Song

    2018-01-01

    Full Text Available The Qinghai-Tibet (QT Plateau Engineering Corridor is located in the hinterland of the QT Plateau, which is highly sensitive to global climate change. Climate change causes permafrost degradation, which subsequently affects vegetation growth. This study focused on the vegetation dynamics and their relationships with climate change and human activities in the region surrounding the QT Plateau Engineering Corridor. The vegetation changes were inferred by applying trend analysis, the Mann-Kendall trend test and abrupt change analysis. Six key regions, each containing 40 nested quadrats that ranged in size from 500 × 500 m to 20 × 20 km, were selected to determine the spatial scales of the impacts from different factors. Cumulative growing season integrated enhanced vegetation index (CGSIEVI values were calculated for each of the nested quadrats of different sizes to indicate the overall vegetation state over the entire year at different spatial scales. The impacts from human activities, a sudden increase in precipitation and permafrost degradation were quantified at different spatial scales using the CGSIEVI values and meteorological data based on the double mass curve method. Three conclusions were derived. First, the vegetation displayed a significant increasing trend over 23.6% of the study area. The areas displaying increases were mainly distributed in the Hoh Xil. Of the area where the vegetation displayed a significant decreasing trend, 72.4% was made up of alpine meadows. Second, more vegetation, especially the alpine meadows, has begun to degenerate or experience more rapid degradation since 2007 due to permafrost degradation and overgrazing. Finally, an active layer depth of 3 m to 3.2 m represents a limiting depth for alpine meadows.

  7. Genetic and epigenetic variations induced by wheat-rye 2R and 5R monosomic addition lines.

    Directory of Open Access Journals (Sweden)

    Shulan Fu

    Full Text Available BACKGROUND: Monosomic alien addition lines (MAALs can easily induce structural variation of chromosomes and have been used in crop breeding; however, it is unclear whether MAALs will induce drastic genetic and epigenetic alterations. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, wheat-rye 2R and 5R MAALs together with their selfed progeny and parental common wheat were investigated through amplified fragment length polymorphism (AFLP and methylation-sensitive amplification polymorphism (MSAP analyses. The MAALs in different generations displayed different genetic variations. Some progeny that only contained 42 wheat chromosomes showed great genetic/epigenetic alterations. Cryptic rye chromatin has introgressed into the wheat genome. However, one of the progeny that contained cryptic rye chromatin did not display outstanding genetic/epigenetic variation. 78 and 49 sequences were cloned from changed AFLP and MSAP bands, respectively. Blastn search indicated that almost half of them showed no significant similarity to known sequences. Retrotransposons were mainly involved in genetic and epigenetic variations. Genetic variations basically affected Gypsy-like retrotransposons, whereas epigenetic alterations affected Copia-like and Gypsy-like retrotransposons equally. Genetic and epigenetic variations seldom affected low-copy coding DNA sequences. CONCLUSIONS/SIGNIFICANCE: The results in the present study provided direct evidence to illustrate that monosomic wheat-rye addition lines could induce different and drastic genetic/epigenetic variations and these variations might not be caused by introgression of rye chromatins into wheat. Therefore, MAALs may be directly used as an effective means to broaden the genetic diversity of common wheat.

  8. Vegetation-zonation patterns across a temperate mountain cloud forest ecotone are not explained by variation in hydraulic functioning or water relations.

    Science.gov (United States)

    Berry, Z Carter; Johnson, Daniel M; Reinhardt, Keith

    2015-09-01

    Many studies have demonstrated linkages between the occurrence of fog and ecophysiological functioning in cloud forests, but few have investigated hydraulic functioning as a determining factor that explains sharp changes in vegetation. The objective of this study was to compare the plant water status during cloud-immersed and non-immersed conditions and hydraulic vulnerability in branches and roots of species across a temperate, mountain fog ecotone. Because cloud forests are often dark, cool and very moist, we expected cloud forest species to have less drought-tolerant characteristics (i.e., lower Pe and P50-the pressures required to induce a 12 and 50% loss in hydraulic conductivity, respectively) relative to non-cloud forest species in adjacent (lower elevation) forests. Additionally, due to the ability of cloud forest species to absorb cloud-fog water, we predicted greater improvements in hydraulic functioning during fog in cloud forest species relative to non-cloud forest species. Across the cloud forest ecotone, most species measured were very resistant to losses in conductivity with branch P50 values from -4.5 to -6.0 MPa, hydraulic safety margins (Ψmin - P50) >1.5 MPa and low calculated hydraulic conductivity losses. Roots had greater vulnerabilities, with P50 values ranging from -1.4 to -2.5 MPa, leading to greater predicted losses in conductivity (∼20%). Calculated values suggested strong losses of midday leaf hydraulic conductance in three of the four species, supporting the hydraulic segmentation hypothesis. In both cloud forest and hardwood species, Ψs were greater on foggy days than sunny days, demonstrating the importance of fog periods to plant water balance across fog regimes. Thus, frequent fog did not result in systemic changes in hydraulic functioning or vulnerability to embolism across our temperate cloud forest ecotone. Finally, roots functioned with lower hydraulic conductivity than branches, suggesting that they may serve as more

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

    Science.gov (United States)

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

    2018-09-01

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

  10. Magnetic memory signals variation induced by applied magnetic field and static tensile stress in ferromagnetic steel

    International Nuclear Information System (INIS)

    Huang, Haihong; Yang, Cheng; Qian, Zhengchun; Han, Gang; Liu, Zhifeng

    2016-01-01

    Stress can induce a spontaneous magnetic field in ferromagnetic steel under the excitation of geomagnetic field. In order to investigate the impact of applied magnetic field and tensile stress on variation of the residual magnetic signals on the surface of ferromagnetic materials, static tensile tests of Q235 structural steel were carried out, with the normal component of the residual magnetic signals, H p (y), induced by applied magnetic fields with different intensities measured through the tensile tests. The H p (y), its slope coefficient K S and maximum gradient K max changing with the applied magnetic field H and tensile stress were observed. Results show that the magnitude of H p (y) and its slope coefficient K S increase linearly with the increase of stress in the elastic deformation stage. Under yield stress, H p (y) and K S reach its maximum, and then decrease slightly with further increase of stress. Applied magnetic field affects the magnitude of H p (y) instead of changing the signal curve′s profile; and the magnitude of H p (y), K S , K max and the change rate of K S increase with the increase of applied magnetic field. The phenomenon is also discussed from the viewpoint of magnetic charge in ferromagnetic materials. - Highlights: • We investigated how applied magnetic field and tensile stress impact H p (y) signals. • Magnitude of H p (y), K S and K max increase with the increase of applied magnetic field. • Both applied magnetic field and tensile stress impact material magnetic permeability. • Applied magnetic field can help to evaluate the stress distribution of components.

  11. Magnetic memory signals variation induced by applied magnetic field and static tensile stress in ferromagnetic steel

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haihong, E-mail: huanghaihong@hfut.edu.cn; Yang, Cheng; Qian, Zhengchun; Han, Gang; Liu, Zhifeng

    2016-10-15

    Stress can induce a spontaneous magnetic field in ferromagnetic steel under the excitation of geomagnetic field. In order to investigate the impact of applied magnetic field and tensile stress on variation of the residual magnetic signals on the surface of ferromagnetic materials, static tensile tests of Q235 structural steel were carried out, with the normal component of the residual magnetic signals, H{sub p}(y), induced by applied magnetic fields with different intensities measured through the tensile tests. The H{sub p}(y), its slope coefficient K{sub S} and maximum gradient K{sub max} changing with the applied magnetic field H and tensile stress were observed. Results show that the magnitude of H{sub p}(y) and its slope coefficient K{sub S} increase linearly with the increase of stress in the elastic deformation stage. Under yield stress, H{sub p}(y) and K{sub S} reach its maximum, and then decrease slightly with further increase of stress. Applied magnetic field affects the magnitude of H{sub p}(y) instead of changing the signal curve′s profile; and the magnitude of H{sub p}(y), K{sub S}, K{sub max} and the change rate of K{sub S} increase with the increase of applied magnetic field. The phenomenon is also discussed from the viewpoint of magnetic charge in ferromagnetic materials. - Highlights: • We investigated how applied magnetic field and tensile stress impact H{sub p}(y) signals. • Magnitude of H{sub p}(y), K{sub S} and K{sub max} increase with the increase of applied magnetic field. • Both applied magnetic field and tensile stress impact material magnetic permeability. • Applied magnetic field can help to evaluate the stress distribution of components.

  12. Common Variation in the NOS1AP Gene Is Associated With Drug-Induced QT Prolongation and Ventricular Arrhythmia

    NARCIS (Netherlands)

    Jamshidi, Yalda; Nolte, Ilja M.; Dalageorgou, Chrysoula; Zheng, Dongling; Johnson, Toby; Bastiaenen, Rachel; Ruddy, Suzanne; Talbott, Daniel; Norris, Kris J.; Snieder, Harold; George, Alfred L.; Marshall, Vanessa; Shakir, Saad; Kannankeril, Prince J.; Munroe, Patricia B.; Camm, A. John; Jeffery, Steve; Roden, Dan M.; Behr, Elijah R.

    2012-01-01

    Objectives This study sought to determine whether variations in NOS1AP affect drug-induced long QT syndrome (LQTS). Background Use of antiarrhythmic drugs is limited by the high incidence of serious adverse events including QT prolongation and torsades de pointes. NOS1AP gene variants play a role in

  13. Possible individual variation in susceptibility to radiation-induced genetic changes

    International Nuclear Information System (INIS)

    Gentner, N.E.; Walker, J.A.

    1990-01-01

    Several studies have shown variation between individuals in radiosensitivity. A person could have a high level of cytogenetic indicator because of high exposure or high susceptibility. To relate spontaneous cytogenetic end-points to dose it is advisable to have a measure of both the spontaneous level and of induced susceptibility. These end points need to be compared in irradiated persons who have developed cancer versus those who have not, as a guide to what end points are appropriate for susceptibility to radiogenic cancer. The use of inbred rodent strains may not be appropriate to derive specific locus mutation data relevant to the human situation, in which large differences in susceptibility appear to exist. Variability in response because of differential DNA repair capacity should be kept in mind when evaluating existing human data. For accident situations, using acute exposures for testing susceptibility may be appropriate, but to be relevant to low dose, low dose rate exposures, more use of protracted dose delivery in testing is recommended. There is a need for international collaborative study where these different tests are done on the same donors at the same time. It might now be prudent for radiation protection to take into account the occurrence of critical groups in the population on the basis of their increased radiation sensitivity. (12 refs., 3 figs.)

  14. Radiation induced variation in potato for tolerance to salinity using tissue culture technique

    International Nuclear Information System (INIS)

    Sharabash, M.T.

    2001-01-01

    Meristem-tips of potato (Solanum tuberosum) cv. 'Diamant', obtained from tuber sprouts, were cultured on MS medium, and multiplied into plantlets through micropropagation. To induce variation for salt tolerance, the obtained plantlets were irradiated with 0, 20, and 40 Gy gamma rays at 27.7 rad/sec. Irradiated plantlets were cut into single nodes and cultured on MS medium, supplemented with 2000 and 4000 ppm NaCI. Salt tolerant plantlets were transferred for tuberization on MS liquid medium supplemented with the same concentration of NaCI. Micro-tubers, collected after 6 weeks of culture, had fresh weight between 0.03 to 0.3 g. Mini-tubers were obtained by planting micro-tubers in 25 cm pots under insect proof greenhouse. Mini-tuber number per plant ranged from 3 to 6, and the mini-tuber weight ranged from 0.5-3.0 g, depending upon the treatment. Further studies are in progress to produce conventional tubers under salinity stress from the promising variants, specially those tolerant to 4000 ppm, and to assure the stability of the obtained variants. (author)

  15. Few single nucleotide variations in exomes of human cord blood induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Rui-Jun Su

    Full Text Available The effect of the cellular reprogramming process per se on mutation load remains unclear. To address this issue, we performed whole exome sequencing analysis of induced pluripotent stem cells (iPSCs reprogrammed from human cord blood (CB CD34(+ cells. Cells from a single donor and improved lentiviral vectors for high-efficiency (2-14% reprogramming were used to examine the effects of three different combinations of reprogramming factors: OCT4 and SOX2 (OS, OS and ZSCAN4 (OSZ, OS and MYC and KLF4 (OSMK. Five clones from each group were subject to whole exome sequencing analysis. We identified 14, 11, and 9 single nucleotide variations (SNVs, in exomes, including untranslated regions (UTR, in the five clones of OSMK, OS, and OSZ iPSC lines. Only 8, 7, and 4 of these, respectively, were protein-coding mutations. An average of 1.3 coding mutations per CB iPSC line is remarkably lower than previous studies using fibroblasts and low-efficiency reprogramming approaches. These data demonstrate that point nucleotide mutations during cord blood reprogramming are negligible and that the inclusion of genome stabilizers like ZSCAN4 during reprogramming may further decrease reprogramming-associated mutations. Our findings provide evidence that CB is a superior source of cells for iPSC banking.

  16. Promise and Capability of NASA's Earth Observing System to Monitor Human-Induced Climate Variations

    Science.gov (United States)

    King, M. D.

    2003-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. The Moderate Resolution Imaging Spectroradiometer (MODIS), developed as part of the Earth Observing System (EOS) and launched on Terra in December 1999 and Aqua in May 2002, is designed to meet the scientific needs for satellite remote sensing of clouds, aerosols, water vapor, and land and ocean surface properties. This sensor and multi-platform observing system is especially well suited to observing detailed interdisciplinary components of the Earth s surface and atmosphere in and around urban environments, including aerosol optical properties, cloud optical and microphysical properties of both liquid water and ice clouds, land surface reflectance, fire occurrence, and many other properties that influence the urban environment and are influenced by them. In this presentation I will summarize the current capabilities of MODIS and other EOS sensors currently in orbit to study human-induced climate variations.

  17. Dielectric Properties of Marsh Vegetation in a Frequency Range of 0.1-18 GHz Under Variation of Temperature and Moisture

    Science.gov (United States)

    Romanov, A. N.; Kochetkova, T. D.; Suslyaev, V. I.; Shcheglova, A. S.

    2017-09-01

    Dielectric characteristics of some species of marsh vegetation: lichen Cladonia stellaris (Opiz) Pouzar, moss Sphagnum, and a representative of Bryidae mosses - Dicranum polysetum are studied in the frequency range from 100 MHz to 18 GHz. At a frequency of 1.41 GHz, the influence of temperature in the range from -12 to +20°C on the behavior of dielectric characteristics of mosses, lichens, and peat is studied. The dependences of the dielectric characteristics of vegetation on the volumetric wetness are established.

  18. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China.

    Directory of Open Access Journals (Sweden)

    Jien Zhang

    Full Text Available In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05. The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China's afforestation program.

  19. A comparison of effects of lard and hydrogenated vegetable shortening on the development of high-fat diet-induced obesity in rats.

    Science.gov (United States)

    Kubant, R; Poon, A N; Sánchez-Hernández, D; Domenichiello, A F; Huot, P S P; Pannia, E; Cho, C E; Hunschede, S; Bazinet, R P; Anderson, G H

    2015-12-14

    Obesity is associated with increased consumption and preference for dietary fat. Experimental models of fat-induced obesity use either lard or vegetable shortening. Yet, there are no direct comparisons of these commonly used fat sources, or the influence of their fatty acid composition, on the development of diet-induced obesity. To compare the effects of lard and hydrogenated vegetable-shortening diets, which differ in their fatty acid composition, on weight gain and the development of obesity and insulin resistance in rats. Male Wistar rats were fed ad libitum for 14 weeks high-fat diets containing either (1) high vegetable fat (HVF, 60 kcal% from vegetable shortening) or (2) high lard fat (HLF, 60 kcal% from lard). Rats fed normal-fat (NF, 16 kcal% from vegetable shortening) diet served as control. Body weight, food intake, adipose tissue mass, serum 25[OH]D3, glucose, insulin and fatty acid composition of diets were measured. Rats fed either of the two high-fat diets had higher energy intake, weight gain and fat accretion than rats fed normal-fat diet. However, rats fed the HLF diet consumed more calories and gained more weight and body fat with greater increases of 32% in total (158.5±8.2 vs 120.2±6.6 g, P<0.05), 30% in visceral (104.4±5.2 vs 80.3±4.2 g, P<0.05) and 36% in subcutaneous fat mass (54.1±3.6 vs 39.9±3.1 g, P<0.05), compared with rats fed the HVF diet. Higher visceral adiposity was positively correlated with serum insulin (r=0.376, P<0.05) and homeostatic model assessment insulin resistance (r=0.391, P<0.05). We conclude that lard-based high-fat diets accentuate the increase in weight gain and the development of obesity and insulin resistance more than hydrogenated vegetable-shortening diets. These results further point to the importance of standardizing fatty acid composition and type of fat used in determining outcomes of consuming high-fat diets.

  20. Variation in soil enzyme activity as a function of vegetation amount, type, and spatial structure in fire-prone Mediterranean shrublands

    NARCIS (Netherlands)

    Garcia Mayor, Angeles; Goirán, Silvana B.; Vallejo, Ramón V.; Bautista, Susana

    2016-01-01

    Fire-prone Mediterranean shrublands may be seriously threatened by land degradation due to progressive opening of the vegetation cover driven by increasing drought and fire recurrence. However, information about the consequences of this opening process for critical ecosystem functions is scant.

  1. Explaining variations in the diversity of parasitoid assemblages in a biosphere reserve of Mexico: evidence from vegetation, land management and seasonality.

    Science.gov (United States)

    González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H; Ballina-Gómez, H S

    2017-11-23

    Insect fauna biodiversity in natural protected areas has not been thoroughly studied. Therefore, the aim of this work was to assess whether and how vegetation types, land management and seasonality influence the diversity of Ichneumonidae (Hymenoptera) in the Ría Lagartos Biosphere Reserve (Mexico). A sampling programme was conducted using Malaise traps from 2008 to 2009 in three vegetation types, each with two conservation zones (core and buffer zones). Three seasons were considered: rainy, dry and north-winds (isolated storms from November to February). A total of 336 species were identified. Rarefaction and Generalized Linear Model indicated higher species richness and abundance, respectively, in the buffer zone of the dry forest; possible explanations for this finding include the intermediate disturbance hypothesis, wherein diversity can be higher in sites where disturbance is not very frequent or very intense, and the 'enemies hypothesis', wherein structural complexity and high plant diversity favour increased predators or, in this case, parasitoids. Diversity was higher during the rainy season, which may have been due to the higher availability of resources. Vegetation and management had a positive impact on the Coc (attack cocoons and pupae) and Myc (attack concealed larvae living in the fruiting bodies of mushrooms) parasitoid guilds. Members of the Coc guild are generalist parasitoids, which may be favoured in complex vegetation with a high richness of potential hosts and non-hosts. The Myc guild requires certain environmental conditions that promote fungal growth, such as humidity, that is absent in the other vegetation types of savannah and coastal dune scrubland.

  2. Assessing Vegetation Cover Dynamics Induced by Policy-Driven Ecological Restoration and Implication to Soil Erosion in Southern China.

    Science.gov (United States)

    Zhang, Jien; Wang, Tianming; Ge, Jianping

    2015-01-01

    In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China's afforestation program.

  3. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes; a food irradiation study on radiation induced stress in vegetable products

    NARCIS (Netherlands)

    Bergers, W.W.A.

    1980-01-01

    Irradiation is a recent preservation method. With the aid of ionizing radiation microorganisms in food can be killed or specific physiological processes in vegetable products can be influenced.

    In order to study the effects of metabolic radiation stress on quantitative chemical changes in

  4. Mechanisms of vegetation-induced channel narrowing of an unregulated canyon river: Results from a natural field-scale experiment

    Science.gov (United States)

    Manners, Rebecca B.; Schmidt, John C.; Scott, Michael L.

    2014-04-01

    The lower Yampa River in Yampa Canyon, western Colorado serves as a natural, field-scale experiment, initiated when the invasive riparian plant, tamarisk (Tamarix spp.), colonized an unregulated river. In response to tamarisk's rapid invasion, the channel narrowed by 6% in the widest reaches since 1961. Taking advantage of this unique setting, we reconstructed the geomorphic and vegetation history in order to identify the key mechanisms for which, in the absence of other environmental perturbations, vegetation alters fluvial processes that result in a narrower channel. From our reconstruction, we identified a distinct similarity in the timing and magnitude of tamarisk encroachment and channel change, albeit with a lag in the channel response, thus suggesting tamarisk as the driving force. Within a decade of establishment, tamarisk effectively trapped sediment and, as a result, increased floodplain construction rates. Increasing tamarisk coverage over time also reduced the occurrence of floodplain stripping. Tamarisk recruitment was driven by both hydrologic and hydraulic variables, and the majority of tamarisk plants (84%) established below the stage of the 2-year flood. Thus, upon establishment nearly all plants regularly interact with the flow and sediment transport field. Our analyses were predicated on the hypothesis that the flow regime of the Yampa River was stationary, and that only the riparian vegetation community had changed. While not heavily impacted by water development, we determined that some aspects of the flow regime have shifted. However, this shift, which involved the clustering in time of extremely wet and dry years, did not influence fluvial processes directly. Instead these changes directly impacted riparian vegetation and changes in vegetation cover, in turn, altered fluvial processes. Today, the rate of channel change and new tamarisk recruitment is small. We believe that the rapid expansion of tamarisk and related floodplain construction

  5. Toward the definition of a carbon budget model: seasonal variation and temperature effect on respiration rate of vegetative and reproductive organs of pistachio trees (Pistacia vera).

    Science.gov (United States)

    Marra, Francesco P; Barone, Ettore; La Mantia, Michele; Caruso, Tiziano

    2009-09-01

    This study, as a preliminary step toward the definition of a carbon budget model for pistachio trees (Pistacia vera L.), aimed at estimating and evaluating the dynamics of respiration of vegetative and reproductive organs of pistachio tree. Trials were performed in 2005 in a commercial orchard located in Sicily (370 m a.s.l.) on five bearing 20-year-old pistachio trees of cv. Bianca grafted onto Pistachio terebinthus L. Growth analyses and respiration measurements were done on vegetative (leaf) and reproductive (infructescence) organs during the entire growing season (April-September) at biweekly intervals. Results suggested that the respiration rates of pistachio reproductive and vegetative organs were related to their developmental stage. Both for leaf and for infructescence, the highest values were observed during the earlier stages of growth corresponding to the phases of most intense organ growth. The sensitivity of respiration activity to temperature changes, measured by Q(10), showed an increase throughout the transition from immature to mature leaves, as well as during fruit development. The data collected were also used to estimate the seasonal carbon loss by respiration activity for a single leaf and a single infructescence. The amount of carbon lost by respiration was affected by short-term temperature patterns, organ developmental stage and tissue function.

  6. Exercise-Induced Rhabdomyolysis and Stress-Induced Malignant Hyperthermia Events, Association with Malignant Hyperthermia Susceptibility, and RYR1 Gene Sequence Variations

    Directory of Open Access Journals (Sweden)

    Antonella Carsana

    2013-01-01

    Full Text Available Exertional rhabdomyolysis (ER and stress-induced malignant hyperthermia (MH events are syndromes that primarily afflict military recruits in basic training and athletes. Events similar to those occurring in ER and in stress-induced MH events are triggered after exposure to anesthetic agents in MH-susceptible (MHS patients. MH is an autosomal dominant hypermetabolic condition that occurs in genetically predisposed subjects during general anesthesia, induced by commonly used volatile anesthetics and/or the neuromuscular blocking agent succinylcholine. Triggering agents cause an altered intracellular calcium regulation. Mutations in RYR1 gene have been found in about 70% of MH families. The RYR1 gene encodes the skeletal muscle calcium release channel of the sarcoplasmic reticulum, commonly known as ryanodine receptor type 1 (RYR1. The present work reviews the documented cases of ER or of stress-induced MH events in which RYR1 sequence variations, associated or possibly associated to MHS status, have been identified.

  7. Flight biomechanics of developmentally-induced size variation in the solitary bee Osmia lignaria

    Science.gov (United States)

    Body size covaries with morphology, functional performance, and fitness. For insects, variation in adult phenotypies are derived from developmental variation in larval growth and metamorphosis. In this study, we asked how larval growth impacted adult morphology in Osmia lignaria—especially traits th...

  8. Minimal Contribution of APOBEC3-Induced G-to-A Hypermutation to HIV-1 Recombination and Genetic Variation.

    Science.gov (United States)

    Delviks-Frankenberry, Krista A; Nikolaitchik, Olga A; Burdick, Ryan C; Gorelick, Robert J; Keele, Brandon F; Hu, Wei-Shau; Pathak, Vinay K

    2016-05-01

    Although the predominant effect of host restriction APOBEC3 proteins on HIV-1 infection is to block viral replication, they might inadvertently increase retroviral genetic variation by inducing G-to-A hypermutation. Numerous studies have disagreed on the contribution of hypermutation to viral genetic diversity and evolution. Confounding factors contributing to the debate include the extent of lethal (stop codon) and sublethal hypermutation induced by different APOBEC3 proteins, the inability to distinguish between G-to-A mutations induced by APOBEC3 proteins and error-prone viral replication, the potential impact of hypermutation on the frequency of retroviral recombination, and the extent to which viral recombination occurs in vivo, which can reassort mutations in hypermutated genomes. Here, we determined the effects of hypermutation on the HIV-1 recombination rate and its contribution to genetic variation through recombination to generate progeny genomes containing portions of hypermutated genomes without lethal mutations. We found that hypermutation did not significantly affect the rate of recombination, and recombination between hypermutated and wild-type genomes only increased the viral mutation rate by 3.9 × 10-5 mutations/bp/replication cycle in heterozygous virions, which is similar to the HIV-1 mutation rate. Since copackaging of hypermutated and wild-type genomes occurs very rarely in vivo, recombination between hypermutated and wild-type genomes does not significantly contribute to the genetic variation of replicating HIV-1. We also analyzed previously reported hypermutated sequences from infected patients and determined that the frequency of sublethal mutagenesis for A3G and A3F is negligible (4 × 10-21 and1 × 10-11, respectively) and its contribution to viral mutations is far below mutations generated during error-prone reverse transcription. Taken together, we conclude that the contribution of APOBEC3-induced hypermutation to HIV-1 genetic

  9. Spontaneous and UV-induced variations in the activity of biomass synthesis in Candida utilis haploid and diploid strains

    International Nuclear Information System (INIS)

    Kondrat'eva, T.F.; Lin'kova, M.A.; Lobacheva, N.A.

    1988-01-01

    Candida utilis diploid strains have greater variations induced by UV irradiation in the activity of biomass synthesis as compared with the parent haploid culture. Clones with an activity of the synthesis greater that the mean population one appear more frequently in the diploid strains. Mathematical analysis has confirmed the significance of the results and the hypothesis according to which the frequency of variants more active in biomass synthesis rises after the action of UV

  10. Numerical simulation of scouring-deposition variations caused by rainfall-induced landslides in the upstream of Zengwun River, Taiwan

    Science.gov (United States)

    Lee, Ming-Hsi; Liao, Yi-Wen; Tsai, Kuang-Jung

    2017-04-01

    In recent years, the increasing sediment disasters of severe rainfall-induced landslides on human lives and lifeline facilities worldwide have advanced the necessity to find out both economically acceptable and useful techniques to predict the occurrence and destructive power of the disasters. In August 2009, Typhoon Morakot brought a large amount of rainfall with both high intensity and long duration to a vast area of Taiwan. Unfortunately, this resulted in a catastrophic landslide in watershed of Zengwun-River reservoir, southern Taiwan. Meanwhile, large amounts of landslides were formed in the upstream of Zengwun River. The major scope of this study is to apply numerical model to simulate the scouring-deposition variations caused by rainfall-induced landslides that occurred in the upstream of Zengwun River during Typhoon Morakot. This study proposed the relation diagrams of the intermediate diameter (d50), recurrence interval (T) and scouring-deposition depth (D), and applied the diagrams to understand the impacts of the scouring-deposition variations on the structures for water and soil conservation and their measurements. Based on the simulation of scouring-deposition variation at the Da-Bu dam and Da-Bang dam, this study also discussed the scouring-deposition variations of different sections under different scenarios (including flow rate, intermediate diameters and structures). In summary, the result suggested that the diagrams of the intermediate diameter, recurrence interval and scouring-deposition depth could be used as the reference for designing the check dams, ground sills and lateral constructions.

  11. Color variation induced by abutments in the superior anterior maxilla: an in vitro study in the pig gingiva.

    Science.gov (United States)

    Atash, Ramin; Boularbah, Mohamed-Reda; Sibel, Cetik

    2016-12-01

    The aim of this work is to evaluate different types of materials used for making implant abutments, by means of an in vitro study and a review of the literature, in order to identify the indications for a better choice of an implant-supported restoration in the anterior section. 5 implant abutments were tested in a random order in the superior anterior maxilla of pig gingiva (n = 8): titanium dioxide (Nobel Biocare); zirconium dioxide, Standard BO shade (Nobel Biocare, Kloten, Switzerland); zirconium dioxide, Light BI shade (Nobel Biocare); zirconium dioxide, Intense A 3.5 shade (Nobel Biocare); and aluminium oxide. Each abutment was tested for 2 mm and 3 mm thickness. To determine color variation, VITA Easyshade Advance spectrophotometer (Vita Zahnfabrik, Bad Sackingen, Germany) was used. Results showed that the color variation induced by the abutment would be affected by the abutment material and gingival thickness, when the gingival thickness is 2 mm. All materials except zirconium dioxide (Standard shade) caused a visible change of color. Then, as the thickness of the gingiva increased to 3 mm, the color variation was attenuated in a significant manner and became invisible for all types of abutments, except those made of aluminium oxide. Zirconium dioxide is the material causing the lowest color variation at 2 mm and at 3 mm, whereas aluminium oxide causes the highest color variation no matter the thickness.

  12. Hydrologically induced orientation variations of a tri-axial Earth's principal axes based on satellite-gravimetric and hydrological models

    Directory of Open Access Journals (Sweden)

    Shen Wenbin

    2013-05-01

    Full Text Available The Earth is a tri-axial body, with unequal principal inertia moments, A, B and C. The corresponding principal axes a, b and c are determined by the mass distribution of the Earth, and their orientations vary with the mass redistribution. In this study, the hydrologically induced variations are estimated on the basis of satellite gravimetric data, including those from satellite laser ranging (SLR and gravity recovery and climate experiment (GRACE, and hydrological models from global land data assimilation system (GLDAS. The longitude variations of a and b are mainly related to the variations of the spherical harmonic coefficients C¯22 and S¯22, which have been estimated to be consisting annual variations of about 1. 6 arc seconds and 1. 8 arc seconds, respectively, from gravity data. This result is confirmed by land surface water storage provided by the GLDAS model. If the atmospheric and oceanic signals are removed from the spherical harmonic coefficients C¯21 and S¯21, the agreement of the orientation series for c becomes poor, possibly due to the inaccurate background models used in pre-processing of the satellite gravimetric data. Determination of the orientation variations may provide a better understanding of various phenomena in the study of the rotation of a tri-axial Earth.

  13. [Dynamics of vegetative indicators induced by low-frequency magnetotherapy and EHF-puncture in hypertensive workers exposed to vibration].

    Science.gov (United States)

    Drobyshev, V A; Efremov, A V; Loseva, M I; Sukharevskaia, T M; Michurin, A I

    2002-01-01

    Low-frequency magnetic fields and EHF-therapy have been used in correction of autonomic homeostasis in workers exposed to vibration for different periods of time. The workers suffered from early arterial hypertension. Vegetative status and central hemodynamics improved best in workers exposed to vibration for less than 5 years. If the exposure was 6-15 years, a positive trend occurred in the tension of regulatory mechanisms. Workers with long exposure to vibration suffering from vagotonia showed an inadequate response of the autonomic parameters to treatment. This necessitates enhancement of therapeutic measures with medicines.

  14. Variation of radiation sensitivity of Friend Erythroleukemia cells cultured in the presence of the differentiation inducer DMSO

    International Nuclear Information System (INIS)

    Einspenner, M.; Boulton, J.E.; Borsa, J.

    1984-01-01

    Differentiation of Friend erythroleukemia cells (FELC) was induced with 1.5% dimethyl sulfoxide (DMSO) in the culture medium. Cell growth, erythroid differentiation, and radiosensitivity of the proliferative capacity of the cells were measured and compared to a noninduced control culture of identical age. Induced cells first appeared on Day 2 after DMSO addition, and increased to a maximum of 80 to 90% of the cell population on Day 5, whereas in the control culture, induction was less than 2% of the cells. Radiosensitivity of the cells in the induced culture relative to that of cells in the control culture, showed an age-dependent variation. On days 1 and 2 after DMSO addition, the cells in the induced culture were less radiosensitive than those in the control culture. At later times, this relationship was reversed, and between days 3 and 5 the clonable cells in the induced culture were less radiosensitive than those in the control culture. These results suggest that the metabolic events associated with commitment of FELC to differentiate affect their ability to cope with the radiation-induced lesions underlying the loss of division capacity

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

    International Nuclear Information System (INIS)

    De Nicola, Elena; Meric, Suereyya; Gallo, Marialuisa; Iaccarino, Mario; Della Rocca, Claudio; Lofrano, Giusy; Russo, Teresa; Pagano, Giovanni

    2007-01-01

    Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels ≥1 mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3 mg/L when control cultures displayed suboptimal quality, i.e. <70% 'viable' (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects. - Vegetable tannin and synthetic tannins were moderately toxic or displayed hormetic effects in sea urchins and in algae. Re-defining control quality is needed for evaluating hormetic effects

  17. Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

    Energy Technology Data Exchange (ETDEWEB)

    De Nicola, Elena [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy); Meric, Suereyya [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Gallo, Marialuisa [Campania Regional Agency for Environmental Protection (ARPAC), I-80143 Naples (Italy); Iaccarino, Mario [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy); Della Rocca, Claudio [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Lofrano, Giusy [Department of Civil Engineering, Salerno University, I-84084 Fisciano (Italy); Russo, Teresa [Campania Regional Agency for Environmental Protection (ARPAC), I-80143 Naples (Italy); Pagano, Giovanni [Italian National Cancer Institute, G. Pascale Foundation, via M. Semmola, I-80131 Naples (Italy)]. E-mail: gbpagano@tin.it

    2007-03-15

    Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels {>=}1 mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3 mg/L when control cultures displayed suboptimal quality, i.e. <70% 'viable' (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects. - Vegetable tannin and synthetic tannins were moderately toxic or displayed hormetic effects in sea urchins and in algae. Re-defining control quality is needed for evaluating hormetic effects.

  18. [Association between variations in protocadherin 15 gene and occupational noise-induced hearing loss].

    Science.gov (United States)

    Xu, X R; Yang, Q Y; Jiao, J; Zheng, Y X; He, L H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Li, Y H; Zhang, H L; Zhang, Z R

    2017-01-06

    Objective: The aim of this study was to investigate whether genetic variability in the protocadherin 15 (PCDH15) gene may correspond with increased susceptibility to noise-induced hearing loss (NIHL) in a Chinese population. Methods: A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In this study, 394 cases who had an average hearing threshold of more than 40 dB (A) in high frequency were defined as the case group, and 721 controls who had an average hearing threshold of less than 35 dB (A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. A questionnaire was completed by participants and a physical test was also conducted. SNP genotyping was performed using the SNPscan TM Kit. Multivariate unconditional logistic regression additive models were used to analyze the genotypes in different groups, and the association with NIHL. Unconditional logistic regression models were used to assess the associations between the genotypes and NIHL. Results: The average age of study participants was (40.5±8.3) years and the median number of noise-exposed working years M ( P 25 , P 75 ) was 21.1 (9.1, 27.3). The range of noise exposed levels and the levels of cumulative noise exposure (CNE) were 80.1- 98.8 dB(A) and 86.6- 111.2 dB(A), respectively. Only the distribution of the genotypes (TT/CC/CT) of rs11004085 in the PCDH15 gene showed a significant difference between the case and control groups ( P= 0.049). In the case group, the distribution was 370 (93.9%), 24 (6.1%) and 0; in the control group, the distribution was 694 (96.3%), 23 (3.2%) and 1 (0.1% ). After smoking, drinking, hypertension, height and CNE adjustment, compared with the TT genotype individuals with the CC/CT genotype had a 1.90-fold increased risk of NIHL (95% CI: 1.06- 3.40). After stratified these data by the noise exposure level

  19. Major inter-personal variation in the increase and maximal level of 25-hydroxy vitamin D induced by UVB

    DEFF Research Database (Denmark)

    Datta, Pameli; Philipsen, Peter A.; Olsen, Peter

    2016-01-01

    Vitamin D influences skeletal health as well as other aspects of human health. Even when the most obvious sources of variation such as solar UVB exposure, latitude, season, clothing habits, skin pigmentation and ethnicity are selected for, variation in the serum 25-hydroxy vitamin D (25(OH......)D) response to UVB remains extensive and unexplained. Our study assessed the inter-personal variation in 25(OH)D response to UVR and the maximal obtainable 25(OH)D level in 22 healthy participants (220 samples) with similar skin pigmentation during winter with negligible ambient UVB. Participants received...... identical UVB doses on identical body areas until a maximal level of 25(OH)D was reached. Major inter-personal variation in both the maximal obtainable UVB-induced 25(OH)D level (range 85–216 nmol l−1, mean 134 nmol l−1) and the total increase in 25(OH)D (range 3–139 nmol l−1, mean 48 nmol l−1) was found...

  20. The Effect of Variation in Permittivity of Different Tissues on Induced Electric Field in the Brain during Transcranial Magnetic Stimulation

    Science.gov (United States)

    Hadimani, Ravi; Porzig, Konstantin; Crowther, Lawrence; Brauer, Hartmut; Toepfer, Hannes; Jiles, David; Department of Electrical and Computer Engineering, Iowa State University Team; Department of Advanced Electromagnetics, Ilmenau University of Technology Team

    2013-03-01

    Estimation of electric field in the brain during Transcranial Magnetic Stimulation (TMS) requires knowledge of the electric property of brain tissue. Grey and white matters have unusually high relative permittivities of ~ 106 at low frequencies. However, relative permittivity of cerebrospinal fluid is ~ 102. With such a variation it is necessary to consider the effect of boundaries. A model consisting of 2 hemispheres was used in the model with the properties of one hemisphere kept constant at σ1 = 0.1Sm-1 and ɛr 1 = 10 while the properties of the second hemisphere were changed kept at σ2 = 0.1Sm-1 to 2Sm-1 and ɛr 2 = 102 to 105. A 70 mm diameter double coil was used as the source of the magnetic field. The amplitude of the current in the coil was 5488 A at a frequency of 2.9 kHz. The results show that the electric field, E induced during magnetic stimulation is independent of the relative permittivity, ɛr and varies with the conductivity. Thus the variation in E, calculated with homogeneous and heterogeneous head models was due to variation in conductivity of the tissues and not due to variation in permittivities.

  1. Variation of several agronomic and biochemical traits in γ-ray induced mutant soybeans

    International Nuclear Information System (INIS)

    Shim, Kyo Moon; Kim, Sun Hyung; Kim, Nam Soo; Son, Hi Sup; Rhee, Hae Ik

    1996-01-01

    Two soybean cultivars(Paldalkong and Bangsakong) were irradiated with gamma-ray to reduce seed size, which is an important trait for soybean sprout and the derived mutant soybeans were analyzed in several agronomic and biochemical traits. There were high levels of variations in quantitative traits among the mutants. Several mutant lines showed higher yield and smaller seed than their parents. Qualitative traits such as seed coat color or pubescent color were also changed in a few lines. Biochemical variations were also observed among the mutants. In seed storage protein analysis, many mutant lines showed reduced intensities in β-subunits in 7S globulin than their parents and an additional band in the acidic subunit at 31KDa. Two mutant lines derived from Paldalkong showed an additional band and a shifted band of protease inhibitor by electrophoretic analysis. Variations in isozymes and RAPD were also observed among the mutants. Six isozymes(Adh, Est, Gdh, Idh, Mdh and Pgm) among eleven isozymes showed some variations and six out of ten primers showed polymorphic amplified DNA fragments among the mutants. (author)

  2. Variation in the PTEN-induced putative kinase 1 gene associated ...

    Indian Academy of Sciences (India)

    with the increase risk of type 2 diabetes in northern Chinese. YANCHUN QU1†∗ ... and genetic variation analysis have indicated the involvement of PINK1 gene in the ... Qualitative variables were analysed by a chi-squared test. The level of ...

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

    Science.gov (United States)

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

    2014-05-01

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

  4. Climate induced changes in biome distribution, NPP and hydrology for potential vegetation of the Upper Midwest U.S

    Science.gov (United States)

    Motew, M.; Kucharik, C. J.

    2011-12-01

    While much attention is focused on future impacts of climate change on ecosystems, much can be learned about the previous interactions of ecosystems with recent climate change. In this study, we investigated the impacts of climate change on potential vegetation distributions (i.e. grasses, trees, and shrubs) and carbon and water cycling across the Upper Midwest USA from 1948-2007 using the Agro-IBIS dynamic vegetation model. We drove the model using a historical, gridded daily climate data set (temperature, precipitation, humidity, solar radiation, and wind speed) at a spatial resolution of 5 min x 5 min. While trends in climate variables exhibited heterogeneous spatial patterns over the study period, the overall impact of climate change on vegetation productivity was positive. We observed total increases in net primary productivity (NPP) ranging from 20-150 g C m-2, based on linear regression analysis. We determined that increased summer relative humidity, increased annual precipitation and decreased mean maximum summer temperatures were key variables contributing to these positive trends, likely through a reduction in soil moisture stress (e.g., increased available water) and heat stress. Model simulations also illustrated an increase in annual drainage throughout the region of 20-140 mm yr-1, driven by substantial increases in annual precipitation. Evapotranspiration had a highly variable spatial trend over the 60-year period, with total change over the study period ranging between -100 and +100 mm yr-1. We also analyzed potential changes in plant functional type (PFT) distributions at the biome level, but hypothesize that the model may be unable to adequately capture competitive interactions among PFTs as well as the dynamics between upper and lower canopies consisting of trees, grasses and shrubs. An analysis of the bioclimatic envelopes for PFTs common to the region revealed no significant change to the boreal conifer tree climatic domain over the study

  5. The Effect of PCDH15 Gene Variations on the Risk of Noise-induced Hearing Loss in a Chinese Population.

    Science.gov (United States)

    Xu, Xiang Rong; Wang, Jing Jing; Yang, Qiu Yue; Jiao, Jie; He, Li Hua; Yu, Shan Fa; Gu, Gui Zhen; Chen, Guo Shun; Zhou, Wen Hui; Wu, Hui; Li, Yan Hong; Zhang, Huan Ling; Zhang, Zeng Rui; Jin, Xian Ning

    2017-02-01

    Noise-induced hearing loss (NIHL) is a complex disease caused by interactions between environmental and genetic factors. This study investigated whether genetic variability in protocadherin related 15 (PCDH15) underlies an increased susceptibility to the development of NIHL in a Chinese population. The results showed that compared with the TT genotype of rs11004085, CT/CC genotypes were associated with an increased risk of NIHL [adjusted odds ratio (OR) = 2.64; 95% confidence interval (CI): 1.14-6.11, P = 0.024]. Additionally, significant interactions between the rs11004085 and rs978842 genetic variations and noise exposure were observed in the high-level exposure groups (P variations in PCDH15 modify the susceptibility to NIHL development in humans. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  6. Canadian population risk of radon induced lung cancer variation range assessment based on various radon risk models

    International Nuclear Information System (INIS)

    Chen, Jing

    2017-01-01

    To address public concerns regarding radon risk and variations in risk estimates based on various risk models available in the literature, lifetime lung cancer risks were calculated with five well-known risk models using more recent Canadian vital statistics (5-year averages from 2008 to 2012). Variations in population risk estimation among various models were assessed. The results showed that the Canadian population risk of radon induced lung cancer can vary from 5.0 to 17% for men and 5.1 to 18% for women based on different radon risk models. Averaged over the estimates from various risk models with better radon dosimetry, 13% of lung cancer deaths among Canadian males and 14% of lung cancer deaths among Canadian females were attributable to long-term indoor radon exposure. (authors)

  7. Vegetation responses to sagebrush-reduction treatments measured by satellites

    Science.gov (United States)

    Johnston, Aaron; Beever, Erik; Merkle, Jerod A.; Chong, Geneva W.

    2018-01-01

    Time series of vegetative indices derived from satellite imagery constitute tools to measure ecological effects of natural and management-induced disturbances to ecosystems. Over the past century, sagebrush-reduction treatments have been applied widely throughout western North America to increase herbaceous vegetation for livestock and wildlife. We used indices from satellite imagery to 1) quantify effects of prescribed-fire, herbicide, and mechanical treatments on vegetative cover, productivity, and phenology, and 2) describe how vegetation changed over time following these treatments. We hypothesized that treatments would increase herbaceous cover and accordingly shift phenologies towards those typical of grass-dominated systems. We expected prescribed burns would lead to the greatest and most-prolonged effects on vegetative cover and phenology, followed by herbicide and mechanical treatments. Treatments appeared to increase herbaceous cover and productivity, which coincided with signs of earlier senescence − signals expected of grass-dominated systems, relative to sagebrush-dominated systems. Spatial heterogeneity for most phenometrics was lower in treated areas relative to controls, which suggested treatment-induced homogenization of vegetative communities. Phenometrics that explain spring migrations of ungulates mostly were unaffected by sagebrush treatments. Fire had the strongest effect on vegetative cover, and yielded the least evidence for sagebrush recovery. Overall, treatment effects were small relative to those reported from field-based studies for reasons most likely related to sagebrush recovery, treatment specification, and untreated patches within mosaicked treatment applications. Treatment effects were also small relative to inter-annual variation in phenology and productivity that was explained by temperature, snowpack, and growing-season precipitation. Our results indicated that cumulative NDVI, late-season phenometrics, and spatial

  8. Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014

    Science.gov (United States)

    Ma, J.; Xiao, X.; Zhang, Y.; Chen, B.; Zhao, B.

    2017-12-01

    Great significance exists in accurately estimating spatial-temporal patterns of gross primary production (GPP) because of its important role in global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatially time-sires GPP. However, the estimation of the accuracy of GPP simulations from LUE at both spatial and temporal scales is still a challenging work. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images of 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPPVPM) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPPVPM and SIF data over both single year (2010) and multiple years (2007-2014) in China. Annual GPPVPM is significantly positive correlated with SIF (R2>0.43) spatially for all years during 2007-2014 and all seasons in 2010 (R2>0.37). GPP dynamic trends is high spatial-temporal heterogeneous in China during 2007-2014. The results of this study indicate that GPPVPM is temporally and spatially in line with SIF data, and space-borne SIF data have great potential in validating and parameterizing GPP estimation of LUE-based models.

  9. Kuchler Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of potential natural plant communites as compiled and published on 'Map of the Natural Vegetation of California' by A. W. Kuchler, 1976. Source map...

  10. Wieslander Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of the 1945 California Vegetation Type Maps by A. E. Wieslander of the U.S. Forest Service. Source scale of maps are 1:100,000. These compiled maps...

  11. Suitable gamma ray dose determination in order to induce genetic variation in kaboli chickpea (Cicer Arietinum L)

    International Nuclear Information System (INIS)

    Naserian Khiabani, B.; Ahari Mostafavi, H.; Fathollahi, H.; Vedadi, S.; Mosavi Shalmani, M. A.

    2008-01-01

    In spite of chickpea's use in Iran and its ability of being replaced to adjust the shortage of protein in dietary habits, yield production is very low. One of the main reasons for chickpea's low yield production is its sensitiveness to some diseases, pest and environmental stresses. Genetic variation in chickpea is very low, because of its self pollination. In breeding programs, genetic variation plays an essential role so that the induction of genetic variation in plant population is very important for the plant breeders. The induced mutation through different kinds of mutagens is one of the important ways of genetic variation. In this research, first the sensitiveness of four cultivars (ILC.486, Philip86, Bivinich, Jam) were assessed to different gamma ray doses (100, 200, 300, 400 Gy). The results showed that with an increase in gamma ray dose, the growth rate of chickpea's genotypes decreases. In this respect, the decrease of growth rate has a linear relationship with the gamma ray dose and it is independent from the genotypes. The root length is more sensitive to gamma ray doses than its shoot, and it was observed that at the low doses the root growth decreases, comparing to the shoot growth. On the other hand, in high doses of gamma ray growth abrasion (Ageotropism, Albinism and etc.) were observed. Some traits variation (such as leaf shape, leaf size, leaf color, Albinism, etc.) were seen in M 2 generation, and finally to continue the project, three doses of gamma ray (150,200,250) were selected for the next year

  12. Climate vs. tectonic induced variations in Cenozoic sediment supply from western Scandinavia

    DEFF Research Database (Denmark)

    Gołędowski, Bartosz; Nielsen, S.B.; Clausen, O.R.

    The scope of this work is the causality of sediment flux variations from western Scandinavia during the Cenozoic. Over the decades of exploration in the North Sea and in the Norwegian shelf most of these variations were given tectonic causes. During the final period of North Atlantic break......-up (Paleocene-Early Eocene) this link is quite striking, especially in the northern British Isles and in the Faeroe-Shetland Platform where sediment production pulses can be correlated with well documented periods of tectonic activity (e.g. magmatism). However, during the subsequent Cenozoic epochs this link...... is much less constrained. For this period we therefore search for an alternative explanation in terms of climate and climate change [1-3] Methods The extensive seismic and well data set allow investigation of inland erosion rates via the offshore distribution of sediments. However, varying marine...

  13. Possible daily and seasonal variations in quantum interference induced by Chern-Simons gravity.

    Science.gov (United States)

    Okawara, Hiroki; Yamada, Kei; Asada, Hideki

    2012-12-07

    Possible effects of Chern-Simons (CS) gravity on a quantum interferometer turn out to be dependent on the latitude and direction of the interferometer on Earth in orbital motion around the Sun. Daily and seasonal variations in phase shifts are predicted with an estimate of the size of the effects, wherefore neutron interferometry with ~5 m arm length and ~10(-4) phase measurement accuracy would place a bound on a CS parameter comparable to the Gravity Probe B satellite.

  14. Spatio-Temporal Variation and Impact Factors for Vegetation Carbon Sequestration and Oxygen Production Based on Rocky Desertification Control in the Karst Region of Southwest China

    Directory of Open Access Journals (Sweden)

    Mingyang Zhang

    2016-01-01

    Full Text Available The Grain to Green Program (GTGP and eco-environmental emigration have been employed to alleviate poverty and control rocky desertification in the Southwest China Karst region. Carbon sequestration and oxygen production (CSOP is used to indicate major ecological changes, because they involve complex processes of material circulation and energy flow. Using remote sensing images and weather records, the spatiotemporal variation of CSOP was analyzed in a typical karst region of northwest Guangxi, China, during 2000–2010 to determine the effects of the Chinese government’s ecological rehabilitation initiatives implemented in 1999. An increase with substantial annual change and a significant increase (20.94%, p < 0.05 in variation were found from 2000 to 2010. CSOP had a highly clustered distribution in 2010 and was correlated with precipitation and temperature (9.18% and 8.96%, respectively, p < 0.05. CSOP was significantly suppressed by human activities (p < 0.01, r = −0.102 but was consistent with the intensity of GTGP (43.80% positive. The power spectrum of CSOP was consistent with that of the gross domestic product. These results indicate that ecological services were improved by rocky desertification control in a typical karst region. The results may provide information to evaluate the efficiency of ecological reconstruction projects.

  15. Greenhouse Gas Induced Changes in the Seasonal Cycle of the Amazon Basin in Coupled Climate-Vegetation Regional Model

    Directory of Open Access Journals (Sweden)

    Flavio Justino

    2016-01-01

    Full Text Available Previous work suggests that changes in seasonality could lead to a 70% reduction in the extent of the Amazon rainforest. The primary cause of the dieback of the rainforest is a lengthening of the dry season due to a weakening of the large-scale tropical circulation. Here we examine these changes in the seasonal cycle. Under present day conditions the Amazon climate is characterized by a zonal separation of the dominance of the annual and semi-annual seasonal cycles. This behavior is strongly modified under greenhouse warming conditions, with the annual cycle becoming dominant throughout the Amazon basin, increasing differences between the dry and wet seasons. In particular, there are substantial changes in the annual cycle of temperature due to the increase in the temperature of the warmest month, but the lengthening of the dry season is believed to be particularly important for vegetation-climate feedbacks. Harmonic analysis performed to regional climate model simulations yields results that differ from the global climate model that it is forced from, with the regional model being more sensitive to changes in the seasonal cycle.

  16. Ethnic Variations in the Connection between Work-Induced Family Separation and Turnover Intent

    Science.gov (United States)

    Behnke, Andrew O.; MacDermid, Shelley M.; Anderson, James C.; Weiss, Howard M.

    2010-01-01

    Using conservation of resources theory, this study examines the role of resources in the relationship between work-induced family separation and workers' intentions to leave their employment and how these relationships vary across ethnic groups. Analyses of a large representative sample of military members reveal that family separation is…

  17. On the limits of toxicant-induced tolerance testing: cotolerance and response variation of antibiotic effects.

    NARCIS (Netherlands)

    Schmitt, Heike; Martinali, Bennie; Beelen, Patrick van; Seinen, Willem

    2006-01-01

    Pollution-induced community tolerance (PICT) as an ecotoxicological test system has been claimed to detect pollutant effects highly specifically and sensitively. However, the specificity might be limited by the occurrence of cotolerance. Another limitation of the application of any ecotoxicological

  18. Genetic variation among the male sterile cytoplasms induced by gamma irradiation in sugar beets

    International Nuclear Information System (INIS)

    Mikami, Tetsuo; Kinoshita, Toshiro; Takahashi, Man-emon

    1976-01-01

    In sugar beets, cytoplasmic male sterility was induced artificially by radiation treatment. In the present study, four kinds of male sterile strain made from the strain H-2002 with normal cytoplasms were used, and the mode of inheritance of the sterility maintained by these strains was confirmed. Also the hereditary mechanism of pollen fructification recovery was studied, and the newly induced heterotypic property of sterile cytoplasms was examined in comparison with naturally found sterile strains. In each of four produced strains, the male sterility was inherited down to M 4 lines stably through mother plants, and it was presumed that the sterility was caused by highly stable cytoplasmic mutation. In each strain, two pairs of nuclear genes took part in the recovery of pollen fructification, but the mode of action of two genes was different. As the result of mating for verification with O type strain to S cytoplasm strain, it seemed that at least the function as O type was not shown to three strains of γ-60, γ-114 and γ-165, and in the sterile cytoplasms of these three strains, the action of fructification recovery genes different from X and Z arose. It was presumed that the genes of X locus did not take effect in these induced cytoplasms. The possibility that at least four kinds of male sterile cytoplasms different from S were induced from normal cytoplasms by artificial mutation was proved indirectly. (Kako, I.)

  19. Can confinement-induced variations in the viscous dissipation be measured?

    NARCIS (Netherlands)

    de Beer, Sissi; den Otter, Wouter K.; van den Ende, Henricus T.M.; Briels, Willem J.; Mugele, Friedrich

    2012-01-01

    Liquids confined to molecular scales become anisotropic and often show pronounced self-organization such as layering. Although this effect is well accepted, it is still debated if confinement induces measurable changes of viscous friction. We use molecular dynamics to address this issue by

  20. Spatiotemporal variation of surface shortwave forcing from fire-induced albedo change in interior Alaska

    Science.gov (United States)

    Huang, Shengli; Dahal, Devendra; Liu, Heping; Jin, Suming; Young, Claudia J.; Liu, Shuang; Liu, Shu-Guang

    2015-01-01

    The albedo change caused by both fires and subsequent succession is spatially heterogeneous, leading to the need to assess the spatiotemporal variation of surface shortwave forcing (SSF) as a component to quantify the climate impacts of high-latitude fires. We used an image reconstruction approach to compare postfire albedo with the albedo assuming fires had not occurred. Combining the fire-caused albedo change from the 2001-2010 fires in interior Alaska and the monthly surface incoming solar radiation, we examined the spatiotemporal variation of SSF in the early successional stage of around 10 years. Our results showed that while postfire albedo generally increased in fall, winter, and spring, some burned areas could show an albedo decrease during these seasons. In summer, the albedo increased for several years and then declined again. The spring SSF distribution did not show a latitudinal decrease from south to north as previously reported. The results also indicated that although the SSF is usually largely negative in the early successional years, it may not be significant during the first postfire year. The annual 2005-2010 SSF for the 2004 fire scars was -1.30, -4.40, -3.31, -4.00, -3.42, and -2.47 Wm-2. The integrated annual SSF map showed significant spatial variation with a mean of -3.15 Wm-2 and a standard deviation of 3.26 Wm-2, 16% of burned areas having positive SSF. Our results suggest that boreal deciduous fires would be less positive for climate change than boreal evergreen fires. Future research is needed to comprehensively investigate the spatiotemporal radiative and non-radiative forcings to determine the effect of boreal fires on climate.

  1. Annealing induced low coercivity, nanocrystalline Co–Fe–Si thin films exhibiting inverse cosine angular variation

    Energy Technology Data Exchange (ETDEWEB)

    Hysen, T., E-mail: hysenthomas@gmail.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Al-Harthi, Salim; Al-Omari, I.A. [Department of Physics, Sultan Qaboos University, PC 123, Muscat, Sultanate of Oman (Oman); Geetha, P.; Lisha, R. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Ramanujan, R.V. [School of Materials Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Sakthikumar, D. [Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama (Japan); Anantharaman, M.R., E-mail: mra@cusat.ac.in [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

    2013-09-15

    Co–Fe–Si based films exhibit high magnetic moments and are highly sought after for applications like soft under layers in perpendicular recording media to magneto-electro-mechanical sensor applications. In this work the effect of annealing on structural, morphological and magnetic properties of Co–Fe–Si thin films was investigated. Compositional analysis using X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a native oxide surface layer consisting of oxides of Co, Fe and Si on the surface. The morphology of the as deposited films shows mound like structures conforming to the Volmer–Weber growth model. Nanocrystallisation of amorphous films upon annealing was observed by glancing angle X-ray diffraction and transmission electron microscopy. The evolution of magnetic properties with annealing is explained using the Herzer model. Vibrating sample magnetometry measurements carried out at various angles from 0° to 90° to the applied magnetic field were employed to study the angular variation of coercivity. The angular variation fits the modified Kondorsky model. Interestingly, the coercivity evolution with annealing deduced from magneto-optical Kerr effect studies indicates a reverse trend compared to magetisation observed in the bulk. This can be attributed to a domain wall pinning at native oxide layer on the surface of thin films. The evolution of surface magnetic properties is correlated with morphology evolution probed using atomic force microscopy. The morphology as well as the presence of the native oxide layer dictates the surface magnetic properties and this is corroborated by the apparent difference in the bulk and surface magnetic properties. - Highlights: • The relation between grain size and magnetic properties in Co–Fe–Si thin films obeys the Herzer model. • Angular variation of coercivity is found to obey the Kondorsky model. • The MOKE measurements provide further evidence for domain wall pinning.

  2. A marked animal-vegetal polarity in the localization of Na(+),K(+) -ATPase activity and its down-regulation following progesterone-induced maturation.

    Science.gov (United States)

    Mohanty, Basant Kumar; Gupta, Brij L

    2012-02-01

    The stage-VI Xenopus oocyte has a very distinct animal-vegetal polarity with structural and functional asymmetry. In this study, we show the expression and distribution pattern of Na(+),K(+) -ATPase in stage-VI oocytes, and its changes following progesterone-induced maturation. Using enzyme-specific electron microscopy phosphatase histochemistry, [(3) H]-ouabain autoradiography, and immunofluorescence cytochemistry at light microscopic level, we find that Na(+),K(+) -ATPase activity is mainly confined to the animal hemisphere. Electron microscopy histochemical results also suggest that polarized distribution of Na(+),K(+) -ATPase activity persists following progesterone-induced maturation, and it becomes gradually more polarized towards the animal pole. The time course following progesterone-induced maturation suggests that there is an initial up-regulation and then gradual down-regulation of Na(+),K(+) -ATPase activity leading to germinal vesicle breakdown (GVBD). By GVBD, the Na(+),K(+) -ATPase activity is completely down-regulated due to endocytotic removal of pump molecules from the plasma membrane into the sub-cortical region of the oocyte. This study provides the first direct evidence for a marked asymmetric localization of Na(+),K(+) -ATPase activity in any vertebrate oocyte. Here, we propose that such asymmetry in Na(+),K(+) -ATPase activity in stage-VI oocytes, and their down-regulation following progesterone-induced maturation, is likely to have a role in the active state of the germinal vesicle in stage-VI oocytes and chromosomal condensation after GVBD. Copyright © 2011 Wiley Periodicals, Inc.

  3. Gamma ray irradiation induced optical band gap variations in silica sol-gel doped sucrose

    International Nuclear Information System (INIS)

    Marzouki, F.; Farah, K.; Hamzaoui, A.H; Ben Ouada, H

    2015-01-01

    The silica xerogels doped sucrose was prepared via sol-gel process and exposed at room temperature to different doses of high energy ("6"0Co) gamma irradiation. Changes in the UV-visible and FTIR spectra of pristine and irradiated xerogels with varying of gamma doses rays show variation in the gap energy. It was found that energy gap of the investigated silica xerogels decreases with increasing the gamma irradiation doses. Thereby the irradiated samples reveal behaviour changes, from an insulator (Eg ∼5,8 eV) towards a semiconductor with (Eg ∼ 3.5 eV).

  4. Cytological and morphological variations induced in Capsicum by X-irradiation

    International Nuclear Information System (INIS)

    Subhash, K.; Venkat Rajam, M.

    1983-01-01

    Soaked seeds of Capsicum annuum L. cultivar G5 were subjected to different doses of X-rays in order to study the effect of irradiation, including 1, 3, 5 and 10 kR. Irradiated seeds were allowed to germinate and cytological preparations were made from the root tips in order to study the chromosomal anomalies. Gross chromosomal abnormalities, mostly indicating metaphase unoriented fragments in pairs, bridges at anaphase and telophase with or without fragments or laggards and micronuclei have been noticed. Somatic pairing and cell budding were also recorded. In addition, the frequency of chlorophyll mutations, variations in chlorophyll content and height of the seedlings have been recorded. (author)

  5. Cytological and morphological variations induced in Capsicum by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Subhash, K.; Venkat Rajam, M. (Kakatiya Univ., Warangal (India). Dept. of Botany)

    1983-06-01

    Soaked seeds of Capsicum annuum L. cultivar G5 were subjected to different doses of X-rays in order to study the effect of irradiation, including 1, 3, 5 and 10 kR. Irradiated seeds were allowed to germinate and cytological preparations were made from the root tips in order to study the chromosomal anomalies. Gross chromosomal abnormalities, mostly indicating metaphase unoriented fragments in pairs, bridges at anaphase and telophase with or without fragments or laggards and micronuclei have been noticed. Somatic pairing and cell budding were also recorded. In addition, the frequency of chlorophyll mutations, variations in chlorophyll content and height of the seedlings have been recorded.

  6. Sociolinguistic and Contact-induced Variation in Hungarian Language Use in Subcarpathia, Ukraine

    Directory of Open Access Journals (Sweden)

    István Csernicskó

    2012-01-01

    Full Text Available In addition to showing regional and social variation, the language use of the minority Hungarians of Subcarpathia, Ukraine, also presents a reflection of the region’s complex linguistic history and its effects from contact with Russian and Ukrainian. On the basis of quantitative empirical findings, this study shows Subcarpathian Hungarians to be a sociolinguistically stratified group of speakers whose Hungarian language use varies in a systematic manner according to sex, age, level of education, and place of residence. The paper also outlines some of the main differences in the language use of Hungarians in Subcarpathia and Hungary which are manifested in statistically significant ways.

  7. Prediction of seasonal climate-induced variations in global food production

    DEFF Research Database (Denmark)

    Iizumi, Toshichika; Sakuma, Hirofumi; Yokozawa, Masayuki

    2013-01-01

    attention to the cropping forecasts of important food-exporting countries as well as to their own domestic food production. Given the increased volatility of food markets and the rising incidence of climatic extremes affecting food production, food price spikes may increase in prevalence in future years(2......Consumers, including the poor in many countries, are increasingly dependent on food imports(1) and are thus exposed to variations in yields, production and export prices in the major food-producing regions of the world. National governments and commercial entities are therefore paying increased...

  8. Transgenerational variations in DNA methylation induced by drought stress in two rice varieties with distinguished difference to drought resistance.

    Directory of Open Access Journals (Sweden)

    Xiaoguo Zheng

    Full Text Available Adverse environmental conditions have large impacts on plant growth and crop production. One of the crucial mechanisms that plants use in variable and stressful natural environments is gene expression modulation through epigenetic modification. In this study, two rice varieties with different drought resistance levels were cultivated under drought stress from tilling stage to seed filling stage for six successive generations. The variations in DNA methylation of the original generation (G0 and the sixth generation (G6 of these two varieties in normal condition (CK and under drought stress (DT at seedling stage were assessed by using Methylation Sensitive Amplification Polymorphism (MSAP method. The results revealed that drought stress had a cumulative effect on the DNA methylation pattern of both varieties, but these two varieties had different responses to drought stress in DNA methylation. The DNA methylation levels of II-32B (sensitive and Huhan-3 (resistant were around 39% and 32%, respectively. Genome-wide DNA methylation variations among generations or treatments accounted for around 13.1% of total MSAP loci in II-32B, but was only approximately 1.3% in Huhan-3. In II-32B, 27.6% of total differentially methylated loci (DML were directly induced by drought stress and 3.2% of total DML stably transmitted their changed DNA methylation status to the next generation. In Huhan-3, the numbers were 48.8% and 29.8%, respectively. Therefore, entrainment had greater effect on Huhan-3 than on II-32B. Sequence analysis revealed that the DML were widely distributed on all 12 rice chromosomes and that it mainly occurred on the gene's promoter and exon region. Some genes with DML respond to environmental stresses. The inheritance of epigenetic variations induced by drought stress may provide a new way to develop drought resistant rice varieties.

  9. Plant community variation across a puna landscape in the Chilean Andes Variación en la comunidad vegetal de un paisaje de puna en los Andes chilenos

    Directory of Open Access Journals (Sweden)

    JOHN G LAMBRINOS

    2006-06-01

    Full Text Available We describe patterns of plant species and growth form abundance in the puna vegetation of Parque Nacional Lauca, Chile. At more than 4,300 m, the extreme habitat of the study site supported relatively few species. These few species, however, represented a diverse array of growth forms that were organized with respect to distinct environmental gradients. Both species richness and growth form diversity increased with the degree of habitat rockiness and on more xeric north and east facing slopes. These xeric, rocky sites supported the greatest overall abundance of cushion forms. Less rocky sites with more soil development supported a greater abundance of tussock grass and shrub forms. Congeneric species occupied distinct microhabitats and were often markedly divergent in growth form. These patterns suggest that water and thermal stress are critical forces shaping functional form as well as community organization in the high Andean punaDescribimos los patrones de abundancia de las especies vegetales y las formas de vida en la vegetación de puna en el Parque Nacional Lauca, Chile. A una altitud que excede los 4.300 m de altitud, el hábitat extremo de nuestro sitio de estudio presenta relativamente pocas especies. Dichas especies, sin embargo, representan un arreglo diverso de formas de vida organizadas con respecto a distintos gradientes ambientales. Tanto la riqueza de especies como el hábito de crecimiento aumentaron en los suelos más rocosos y en las pendientes expuestas al norte y al este, cuya vegetación es más xerófila. Dichos sitios presentaron la mayor abundancia en formas de cojines. Los sitios menos rocosos con un suelo más desarrollado presentaron una mayor abundancia de pastos y arbustos. Distintos microhábitats fueron ocupados por especies congénericas que con frecuencia divergieron en su hábito de crecimiento. Los patrones observados sugieren que el agua y el estrés térmico son fuerzas críticas que moldean la forma

  10. Beam-induced pressure variations in a TFTR neutral-beam injector

    International Nuclear Information System (INIS)

    Willis, J.E.; Berkner, K.H.

    1981-10-01

    In neutral-beam injection systems either all or part of the gas flow into the neutralizer comes from the plasma source. When the beam is switched on, ions from the plasma source, which used to contribute to the gas flow, are converted to an energetic beam and are pumped away: hence reducing the gas input to the neutralizer. The large volume of the neutralizer and its high conductance damp out rapid changes; for example, when the gas to the source is first turned on, there is a 230 msec exponential rise time associated with pressure in the neutralizer. The neutralizer in turn acts as a source of gas to the first chamber and the first chamber to the second and so on. Beam dumps become additional sources of gas in the second chamber and target tank as gas molecules are collisionally desorbed from the surface of the dump. A simple analytical model (the equivalent of an electrical RC circuit) of the volumes and conductances of the system has been used to describe the pressure variations. The use of time dependent sources terms in the model gives an estimate of the desorption rate from the dumps and its time variation during a beam pulse

  11. Adaptive force produced by stress-induced regulation of random variation intensity.

    Science.gov (United States)

    Shimansky, Yury P

    2010-08-01

    The Darwinian theory of life evolution is capable of explaining the majority of related phenomena. At the same time, the mechanisms of optimizing traits beneficial to a population as a whole but not directly to an individual remain largely unclear. There are also significant problems with explaining the phenomenon of punctuated equilibrium. From another perspective, multiple mechanisms for the regulation of the rate of genetic mutations according to the environmental stress have been discovered, but their precise functional role is not well understood yet. Here a novel mathematical paradigm called a Kinetic-Force Principle (KFP), which can serve as a general basis for biologically plausible optimization methods, is introduced and its rigorous derivation is provided. Based on this principle, it is shown that, if the rate of random changes in a biological system is proportional, even only roughly, to the amount of environmental stress, a virtual force is created, acting in the direction of stress relief. It is demonstrated that KFP can provide important insights into solving the above problems. Evidence is presented in support of a hypothesis that the nature employs KFP for accelerating adaptation in biological systems. A detailed comparison between KFP and the principle of variation and natural selection is presented and their complementarity is revealed. It is concluded that KFP is not a competing alternative, but a powerful addition to the principle of variation and natural selection. It is also shown KFP can be used in multiple ways for adaptation of individual biological organisms.

  12. Current-induced domain wall motion in magnetic nanowires with spatial variation

    International Nuclear Information System (INIS)

    Ieda, Jun'ichi; Sugishita, Hiroki; Maekawa, Sadamichi

    2010-01-01

    We model current-induced domain wall motion in magnetic nanowires with the variable width. Employing the collective coordinate method we trace the wall dynamics. The effect of the width modulation is implemented by spatial dependence of an effective magnetic field. The wall destination in the potential energy landscape due to the magnetic anisotropy and the spatial nonuniformity is obtained as a function of the current density. For a nanowire of a periodically modulated width, we identify three (pinned, nonlinear, and linear) current density regimes for current-induced wall motion. The threshold current densities depend on the pulse duration as well as the magnitude of wire modulation. In the nonlinear regime, application of ns order current pulses results in wall displacement which opposes or exceeds the prediction of the spin transfer mechanism. The finding explains stochastic nature of the domain wall displacement observed in recent experiments.

  13. Evaluating the role of mitochondrial DNA variation to the genetic predisposition to radiation-induced toxicity

    International Nuclear Information System (INIS)

    Fachal, Laura; Mosquera-Miguel, Ana; Gómez-Caamaño, Antonio; Sánchez-García, Manuel; Calvo, Patricia; Lobato-Busto, Ramón; Salas, Antonio; Vega, Ana

    2014-01-01

    Background and purpose: Mitochondrial DNA common variants have been reported to be associated with the development of radiation-induced toxicity. Using a large cohort of patients, we aimed to validate these findings by investigating the potential role of common European mitochondrial DNA SNPs (mtSNPs) to the development of radio-toxicity. Material and methods: Overall acute and late toxicity data were assessed in a cohort of 606 prostate cancer patients by means of Standardized Total Average Toxicity (STAT) score. We carried out association tests between radiation toxicity and a selection of 15 mtSNPs (and the haplogroups defined by them). Results: Statistically significant association between mtSNPs and haplogroups with toxicity could not be validated in our Spanish cohort. Conclusions: The present study suggests that the mtDNA common variants analyzed are not associated with clinically relevant increases in risk of overall radiation-induced toxicity in prostate cancer patients

  14. VEGETATION MAPPING IN WETLANDS

    Directory of Open Access Journals (Sweden)

    F. PEDROTTI

    2004-01-01

    Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.

  15. Climate vs. tectonic induced variations in Cenozoic sediment supply from western Scandinavia

    DEFF Research Database (Denmark)

    Gołędowski, Bartosz; Nielsen, S.B.; Clausen, O.R.

    Eocene times tectonic activity related to the final stage of opening of the North Atlantic was apparently controlling the sediment input in the North Sea as sediment pulses correlate well with tectonic events. Although there is no signs of Cenozoic tectonic activity onshore Scandinavia (igneous bodies......, faulting), tectonic disturbance related to ocean opening could be responsible for deposition of thick Paleocene wedges along the western coast of Norway. During subsequent Cenozoic periods domal structures in the Norwegian shelf are a proof for mild and protracted compression. However, depositional...... patterns from offshore Scandinavia have been interpreted as a result of significant tectonic movements. In the absence of proofs for active tectonic agents we attempt to explain these sediment input variations as a result of climate fluctuations. The Eocene-Oligocene greenhouse-icehouse climate transition...

  16. Unsaturated zone moisture and vapor movement induced by temperature variations in asphalt barrier field lysimeters

    International Nuclear Information System (INIS)

    Holford, D.J.; Fayer, M.J.

    1990-08-01

    Protective barriers are being considered for use at the Hanford Site to enhance the isolation of radioactive wastes from water, plant, and animal intrusion. Lysimeters were constructed to evaluate the performance of asphalt barrier formulations under natural environmental conditions. These lysimeters were constructed of 1.7-m lengths of PVC pipe that have a diameter of 30 cm. The lysimeters were filled with layers of gravel, coarse sand, and asphalt. The sand and gravel placed under the asphalt barrier were wet when installed. TOUGH was used to conduct simulations to assess the effect of temperature variations on moisture and vapor movement beneath the asphalt layer in field test lysimeters. All variables in TOUGH were converted to double precision so that simulations could be run on a Sun-4 UNIX workstation. A radially symmetric grid was used to simulate the lysimeter. 8 refs., 9 figs

  17. Opposite variations in maternal and neonatal thyroid function induced by iodine supplementation during pregnancy

    DEFF Research Database (Denmark)

    Nøhr, S B; Laurberg, P

    2000-01-01

    Whereas the consequences of extremes in iodine intake are well described, much less is known about the effect of more moderate variations in maternal iodine intake on fetal thyroid function. The present study performed in Denmark with mild to moderate iodine deficiency dealt with the effect...... (P iodine intake in both mothers and neonates. The results suggest that the fetal thyroid, at least in areas of mild iodine deficiency, is more sensitive to the inhibitory effect of iodine...... of maternal iodine supplementation on thyroid function in the mother at term and in the fetus/neonate. Serum was collected consecutively from pregnant women at term (n = 144) and from cord blood (n = 139). Forty-nine women had a regular intake of vitamin and mineral tablets with iodine (150 microg/day) during...

  18. Curvature-induced stiffness and the spatial variation of wavelength in wrinkled sheets.

    Science.gov (United States)

    Paulsen, Joseph D; Hohlfeld, Evan; King, Hunter; Huang, Jiangshui; Qiu, Zhanlong; Russell, Thomas P; Menon, Narayanan; Vella, Dominic; Davidovitch, Benny

    2016-02-02

    Wrinkle patterns in compressed thin sheets are ubiquitous in nature and technology, from the furrows on our foreheads to crinkly plant leaves, from ripples on plastic-wrapped objects to the protein film on milk. The current understanding of an elementary descriptor of wrinkles--their wavelength--is restricted to deformations that are parallel, spatially uniform, and nearly planar. However, most naturally occurring wrinkles do not satisfy these stipulations. Here we present a scheme that quantitatively explains the wrinkle wavelength beyond such idealized situations. We propose a local law that incorporates both mechanical and geometrical effects on the spatial variation of wrinkle wavelength. Our experiments on thin polymer films provide strong evidence for its validity. Understanding how wavelength depends on the properties of the sheet and the underlying liquid or elastic subphase is crucial for applications where wrinkles are used to sculpt surface topography, to measure properties of the sheet, or to infer forces applied to a film.

  19. Prediction of seasonal climate-induced variations in global food production

    Science.gov (United States)

    Iizumi, Toshichika; Sakuma, Hirofumi; Yokozawa, Masayuki; Luo, Jing-Jia; Challinor, Andrew J.; Brown, Molly E.; Sakurai, Gen; Yamagata, Toshio

    2013-10-01

    Consumers, including the poor in many countries, are increasingly dependent on food imports and are thus exposed to variations in yields, production and export prices in the major food-producing regions of the world. National governments and commercial entities are therefore paying increased attention to the cropping forecasts of important food-exporting countries as well as to their own domestic food production. Given the increased volatility of food markets and the rising incidence of climatic extremes affecting food production, food price spikes may increase in prevalence in future years. Here we present a global assessment of the reliability of crop failure hindcasts for major crops at two lead times derived by linking ensemble seasonal climatic forecasts with statistical crop models. We found that moderate-to-marked yield loss over a substantial percentage (26-33%) of the harvested area of these crops is reliably predictable if climatic forecasts are near perfect. However, only rice and wheat production are reliably predictable at three months before the harvest using within-season hindcasts. The reliabilities of estimates varied substantially by crop--rice and wheat yields were the most predictable, followed by soybean and maize. The reasons for variation in the reliability of the estimates included the differences in crop sensitivity to the climate and the technology used by the crop-producing regions. Our findings reveal that the use of seasonal climatic forecasts to predict crop failures will be useful for monitoring global food production and will encourage the adaptation of food systems toclimatic extremes.

  20. The Effect of Ethnic Variation on the Success of Induced Labour in Nulliparous Women with Postdates Pregnancies

    Directory of Open Access Journals (Sweden)

    Dimitrios Papoutsis

    2016-01-01

    Full Text Available Objective. To identify the potential effect of ethnic variation on the success of induction of labour in nulliparous women with postdates pregnancies. Study Design. This was an observational cohort study of women being induced for postdates pregnancies (≥41 weeks between 2007 and 2013. Women induced for stillbirths and with multiple pregnancies were excluded. The primary objective was to identify the effect of ethnicity on the caesarean section (CS delivery rates in this cohort of women. Results. 1,636 nulliparous women were identified with a mean age of 27.2 years. 95.8% of the women were of White ethnic origin, 2.6% were Asian, and 1.6% were of Black ethnic origin. The CS delivery rate was 24.4% in the total sample. Women of Black ethnic origin had a 3.26 times greater likelihood for CS in comparison to White women, after adjusting for maternal age, BMI, smoking, presence of meconium, use of epidural analgesia, fetal gender, birth weight, and head circumference (adjusted OR = 3.26; 95% CI: 1.31–8.08, p = 0.011. Conclusion. We have found that nulliparous women of Black ethnicity demonstrate an almost threefold increased risk of caesarean section delivery when induced for postdates pregnancy.

  1. A microhomology-mediated break-induced replication model for the origin of human copy number variation.

    Directory of Open Access Journals (Sweden)

    P J Hastings

    2009-01-01

    Full Text Available Chromosome structural changes with nonrecurrent endpoints associated with genomic disorders offer windows into the mechanism of origin of copy number variation (CNV. A recent report of nonrecurrent duplications associated with Pelizaeus-Merzbacher disease identified three distinctive characteristics. First, the majority of events can be seen to be complex, showing discontinuous duplications mixed with deletions, inverted duplications, and triplications. Second, junctions at endpoints show microhomology of 2-5 base pairs (bp. Third, endpoints occur near pre-existing low copy repeats (LCRs. Using these observations and evidence from DNA repair in other organisms, we derive a model of microhomology-mediated break-induced replication (MMBIR for the origin of CNV and, ultimately, of LCRs. We propose that breakage of replication forks in stressed cells that are deficient in homologous recombination induces an aberrant repair process with features of break-induced replication (BIR. Under these circumstances, single-strand 3' tails from broken replication forks will anneal with microhomology on any single-stranded DNA nearby, priming low-processivity polymerization with multiple template switches generating complex rearrangements, and eventual re-establishment of processive replication.

  2. Vegetative regeneration

    Science.gov (United States)

    George A. Schier; John R. Jones; Robert P. Winokur

    1985-01-01

    Aspen is noted for its ability to regenerate vegetatively by adventitious shoots or suckers that arise on its long lateral roots. It also produces sprouts from stumps and root collars; but they are not common. In a survey of regeneration after clearcutting mature aspen in Utah. Baker (1918b) found that 92% of the shoots originated from roots, 7% from root collars, and...

  3. Understory vegetation

    Science.gov (United States)

    Steve Sutherland; Todd F. Hutchinson; Jennifer L. Windus

    2003-01-01

    This chapter documents patterns of species composition and diversity within the understory vegetation layer and provides a species list for the four study areas in southern Ohio. Within each of 108 plots, we recorded the frequency of all vascular plant species in sixteen 2-m² quadrats. We recorded 297 species, including 187 forbs (176 perennials, 9 annuals, 2...

  4. Detection of Genetic Variations in Marine Algae Ulva lactuca (Chlorophyta Induced by Heavy Metal Pollutants

    Directory of Open Access Journals (Sweden)

    Basel Saleh

    2015-09-01

    Full Text Available Ulva lactuca (Chlorophyta green macroalgae has been successfully used as bioindicator for heavy metals pollution in ecosystems. Random amplified microsatellite polymorphism (RAMP marker was employed to investigate genetic DNA pattern variability in green U. lactuca 5 days after exposure to Cu, Pb, Cd and Zn heavy metals stress. Genomic template stability (GTS% value was employed as a qualitative DNA changes measurement based on RAMP technique. In this respect, estimated GTS% value was recorded to be 65.215, 64.630, 59.835 and 59.250% for Pb, Cu, Cd and Zn treatment, respectively. Moreover, genetic similarity (GS induced by the above heavy metals was also evaluated to measure genetic distance between algae treated plants and their respective control. In this respect, estimated GS values generated by RAMP marker ranged between 0.576 (between control and Zn treatment - 0.969 (for both case; between Pb and Cu and between Cd and Zn treatment with an average of 0.842. Based upon data presented herein based on variant bands number (VB, GTS% and GS values; the present study could be suggested that Pb and Cu followed similar tendency at genomic DNA changes. Similar finding was also observed with Cd and Zn ions. Thereby, RAMP marker successfully highlighted DNA change patterns induced by heavy metals stress.

  5. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    International Nuclear Information System (INIS)

    Kunita, Itsuki; Kuroda, Shigeru; Nakagaki, Toshiyuki; Ueda, Kei-Ichi; Akita, Dai

    2017-01-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective. (paper)

  6. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    Science.gov (United States)

    Kunita, Itsuki; Ueda, Kei-Ichi; Akita, Dai; Kuroda, Shigeru; Nakagaki, Toshiyuki

    2017-09-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective.

  7. Sleep Loss as a Factor to Induce Cellular and Molecular Inflammatory Variations

    Directory of Open Access Journals (Sweden)

    Gabriela Hurtado-Alvarado

    2013-01-01

    Full Text Available A reduction in the amount of time spent sleeping occurs chronically in modern society. Clinical and experimental studies in humans and animal models have shown that immune function is impaired when sleep loss is experienced. Sleep loss exerts a strong regulatory influence on peripheral levels of inflammatory mediators of the immune response. An increasing number of research projects support the existence of reciprocal regulation between sleep and low-intensity inflammatory response. Recent studies show that sleep deficient humans and rodents exhibit a proinflammatory component; therefore, sleep loss is considered as a risk factor for developing cardiovascular, metabolic, and neurodegenerative diseases (e.g., diabetes, Alzheimer's disease, and multiple sclerosis. Circulating levels of proinflammatory mediators depend on the intensity and duration of the method employed to induce sleep loss. Recognizing the fact that the concentration of proinflammatory mediators is different between acute and chronic sleep-loss may expand the understanding of the relationship between sleep and the immune response. The aim of this review is to integrate data from recent published reports (2002–2013 on the effects of sleep loss on the immune response. This review may allow readers to have an integrated view of the mechanisms involved in central and peripheral deficits induced by sleep loss.

  8. Genetic variation in CFH predicts phenytoin-induced maculopapular exanthema in European-descent patients.

    Science.gov (United States)

    McCormack, Mark; Gui, Hongsheng; Ingason, Andrés; Speed, Doug; Wright, Galen E B; Zhang, Eunice J; Secolin, Rodrigo; Yasuda, Clarissa; Kwok, Maxwell; Wolking, Stefan; Becker, Felicitas; Rau, Sarah; Avbersek, Andreja; Heggeli, Kristin; Leu, Costin; Depondt, Chantal; Sills, Graeme J; Marson, Anthony G; Auce, Pauls; Brodie, Martin J; Francis, Ben; Johnson, Michael R; Koeleman, Bobby P C; Striano, Pasquale; Coppola, Antonietta; Zara, Federico; Kunz, Wolfram S; Sander, Josemir W; Lerche, Holger; Klein, Karl Martin; Weckhuysen, Sarah; Krenn, Martin; Gudmundsson, Lárus J; Stefánsson, Kári; Krause, Roland; Shear, Neil; Ross, Colin J D; Delanty, Norman; Pirmohamed, Munir; Carleton, Bruce C; Cendes, Fernando; Lopes-Cendes, Iscia; Liao, Wei-Ping; O'Brien, Terence J; Sisodiya, Sanjay M; Cherny, Stacey; Kwan, Patrick; Baum, Larry; Cavalleri, Gianpiero L

    2018-01-23

    To characterize, among European and Han Chinese populations, the genetic predictors of maculopapular exanthema (MPE), a cutaneous adverse drug reaction common to antiepileptic drugs. We conducted a case-control genome-wide association study of autosomal genotypes, including Class I and II human leukocyte antigen (HLA) alleles, in 323 cases and 1,321 drug-tolerant controls from epilepsy cohorts of northern European and Han Chinese descent. Results from each cohort were meta-analyzed. We report an association between a rare variant in the complement factor H-related 4 ( CFHR4 ) gene and phenytoin-induced MPE in Europeans ( p = 4.5 × 10 -11 ; odds ratio [95% confidence interval] 7 [3.2-16]). This variant is in complete linkage disequilibrium with a missense variant (N1050Y) in the complement factor H ( CFH ) gene. In addition, our results reinforce the association between HLA-A*31:01 and carbamazepine hypersensitivity. We did not identify significant genetic associations with MPE among Han Chinese patients. The identification of genetic predictors of MPE in CFHR4 and CFH, members of the complement factor H-related protein family, suggest a new link between regulation of the complement system alternative pathway and phenytoin-induced hypersensitivity in European-ancestral patients. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  9. Exercise-induced albuminuria vs circadian variations in blood pressure in type 1 diabetes.

    Science.gov (United States)

    Tadida Meli, Isabelle Hota; Tankeu, Aurel T; Dehayem, Mesmin Y; Chelo, David; Noubiap, Jean Jacques N; Sobngwi, Eugene

    2017-02-15

    To investigated the relationship between exercise-induced ambulatory blood pressure measurement (ABPM) abnormalities in type 1 diabetes mellitus (T1DM) adolescents. We conducted a case-control at the National Obesity Center of the Yaoundé Central Hospital, Cameroon. We compared 24 h ABPM and urinary albumin-to-creatinine ratio (ACR) at rest and after a standardized treadmill exercise between 20 Cameroonian T1DM patients and 20 matched controls. T1DM adolescents were aged 12-18 years, with diabetes for at least one year, without proteinuria, with normal office blood pressure (BP) and renal function according to the general reference population. Non-diabetic controls were adolescents of general population matched for sex, age and BMI. Mean duration of diabetes was 4.2 ± 2.8 years. The mean 24 h systolic blood pressure (SBP) and diastolic blood pressure (DBP) were respectively 116 ± 9 mmHg in the diabetic group vs 111 ± 8 mmHg in the non-diabetic ( P = 0.06), and 69 ± 7 mm Hg vs 66 ± 5 mm Hg ( P = 0.19). There was no difference in the diurnal pattern of BP in diabetes patients and non-diabetic controls (SBP: 118 ± 10 mmHg vs 114 ± 10 mmHg, P = 0.11; DBP: 71 ± 7 mmHg vs 68 ± 6 mmHg, P = 0.22). Nighttime BP was higher in the diabetic group with respect to SBP (112 ± 11 mmHg vs 106 ± 7 mmHg, P = 0.06) and to the mean arterial pressure (MAP) (89 ± 9 mmHg vs 81 ± 6 mmHg, P = 0.06). ACR at rest was similar in both groups (5.5 mg/g vs 5.5 mg/g, P = 0.74), but significantly higher in diabetes patients after exercise (10.5 mg/g vs 5.5 mg/g, P = 0.03). SBP was higher in patients having exercise-induced albuminuria (116 ± 10 mmHg vs 108 ± 10 mmHg, P = 0.09). Exercise-induced albuminuria could be useful for early diagnosis of kidney damage in adolescents with T1DM.

  10. The time series variations of tritium concentration in precipitation and its relationships to the rainfall-inducing air mass

    International Nuclear Information System (INIS)

    Shimada, Jun

    1978-01-01

    The author measured the tritium concentration in precipitation of Tokyo for every ten-day period from August 1972 to May 1974. Judging from the daily synoptic weather chart, the rainfall-inducing air masses in Japan were classified into five types; polar maritime air mass (Pm), polar continental air mass (Pc), tropical maritime air mass (Tm), tropical continental air mass (Tc), and equatorial maritime air mass (Em). And the precipitation for every ten-day period sampled for tritium measurement were classified into these five types. Based on this classification, it is confirmed that there exist clear difference in the tritium concentration between the rainfall from the continental air mass and ones from the maritime air mass. It is characteristic that the tritium concentration in rainfall induced by equatorial maritime air mass such as typhoon in summer and early fall season is very low whereas the tritium concentration in rainfall and snowfall induced directly by the polar continental air mass in late winter season is very high. The regional difference of the tritium concentration in intermonthly precipitation could considerably be explained by this synoptic meteological classification of rainfall-inducing air mass. In spite of these regional difference of tritium concentration in precipitation, use of the tritium concentration of Tokyo as a representative value of Japan may be allowed because of the similarities of the changing pattern and annual mean tritium concentration. The time series variations of tritium concentration in precipitation of Tokyo from August 1972 to December 1977, Tsukuba from December 1976 to April 1978, and Nagaoka from April 1977 to March 1978 are listed. (author)

  11. Genomic and proteomic analysis of soybean heritable variations induced by space flight

    Institute of Scientific and Technical Information of China (English)

    HE Jie; GAO Yong; SUN Ye-qing

    2009-01-01

    To analyze the biological effects of space environment, the diversity of genomic DNA between the space flight soybean 194(4126) with phenotype of good yield and good fruit quality induced by space flight and the soybean with ground control was studied by amplified fragment length polymorphism (AFLP) method, and the polymorphism of space flight soybean 194(4126) was 3.56%. The differences of protein expression of seeds and leaves between the two kinds of soybeans were analysed by two-dimensional electrophoresis, PDQuest software and MALDI-TOF mass spectrometry. Results show that the loss and decrease of protein expression in 194(4126) soybean are subjected to the space fight of seeds, and three special proteins including Dehydrin, MAT1 and ceQORH are identified. It is concluded that the space environment changes the phenotype and geno-type of soybeans due to the space flight of seeds.

  12. CO2 induced climatic change and spectral variations in the outgoing terrestrial infrared radiation

    Science.gov (United States)

    Charlock, T. P.

    1984-01-01

    The published temperature changes produced in general circulation model simulations of CO2 induced climate modification are used to compute the top of the atmosphere, clear sky outgoing infrared radiance changes expected for doubled CO2. A significant wavenumber shift is produced, with less radiance emerging in the 500-800 per cm (20.0-12.5 micron) CO2 band and with more emerging in the 800-1200 per cm (12.5-8.3 micron) window. The effect varies greatly with latitude. The radiance shift in the 2300 per cm (4.3 micron) region is of the order of 10-30 percent for doubled CO2. It is suggested that the 2300 per cm region be carefully monitored as an aid in detecting the climatic effects of increasing CO2. The change in the wavenumber-integrated radiant exitance is at most a few percent.

  13. Surface modification induced phase transformation and structure variation on the rapidly solidified recast layer of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ming-Hung [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaoshiung University of Applied Sciences, Kaoshiung 807, Taiwan (China); School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Haung, Chiung-Fang [School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Division of Family and Operative Dentistry, Department of Dentistry, Taipei Medical University Hospital, Taipei 110, Taiwan (China); Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 110, Taiwan (China); Shyu, Shih-Shiun [Department of Dentistry, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan (China); Chou, Yen-Ru [Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 110, Taiwan (China); Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Research Center for Biomedical Implants and Microsurgery Devices, Taipei Medical University, Taipei 110, Taiwan (China); Lin, Ming-Hong [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaoshiung University of Applied Sciences, Kaoshiung 807, Taiwan (China); Peng, Pei-Wen, E-mail: apon@tmu.edu.tw [School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); and others

    2015-08-15

    In this study, neodymium-doped yttrium orthovanadate (Nd:YVO{sub 4}) as a laser source with different scanning speeds was used on biomedical Ti surface. The microstructural and biological properties of laser-modified samples were investigated by means of optical microscope, electron microscope, X-ray diffraction, surface roughness instrument, contact angle and cell cytotoxicity assay. After laser modification, the rough volcano-like recast layer with micro-/nanoporous structure and wave-like recast layer with nanoporous structure were generated on the surfaces of laser-modified samples, respectively. It was also found out that, an α → (α + rutile-TiO{sub 2}) phase transition occurred on the recast layers of laser-modified samples. The Ti surface becomes hydrophilic at a high speed laser scanning. Moreover, the cell cytotoxicity assay demonstrated that laser-modified samples did not influence the cell adhesion and proliferation behaviors of osteoblast (MG-63) cell. The laser with 50 mm/s scanning speed induced formation of rough volcano-like recast layer accompanied with micro-/nanoporous structure, which can promote cell adhesion and proliferation of MG-63 cell on Ti surface. The results indicated that the laser treatment was a potential technology to enhance the biocompatibility for titanium. - Highlights: • Laser induced the formation of recast layer with micro-/nanoporous structure on Ti. • An α → (α + rutile-TiO{sub 2}) phase transition was observed within the recast layer. • The Ti surface becomes hydrophilic at a high speed laser scanning. • Laser-modified samples exhibit good biocompatibility to osteoblast (MG-63) cell.

  14. Capacitance variation induced by microfluidic two-phase flow across insulated interdigital electrodes in lab-on-chip devices.

    Science.gov (United States)

    Dong, Tao; Barbosa, Cátia

    2015-01-26

    Microfluidic two-phase flow detection has attracted plenty of interest in various areas of biology, medicine and chemistry. This work presents a capacitive sensor using insulated interdigital electrodes (IDEs) to detect the presence of droplets in a microchannel. This droplet sensor is composed of a glass substrate, patterned gold electrodes and an insulation layer. A polydimethylsiloxane (PDMS) cover bonded to the multilayered structure forms a microchannel. Capacitance variation induced by the droplet passage was thoroughly investigated with both simulation and experimental work. Olive oil and deionized water were employed as the working fluids in the experiments to demonstrate the droplet sensor. The results show a good sensitivity of the droplet with the appropriate measurement connection. This capacitive droplet sensor is promising to be integrated into a lab-on-chip device for in situ monitoring/counting of droplets or bubbles.

  15. Circadian variations of interferon-induced enhancement of human natural killer (NK) cell activity.

    Science.gov (United States)

    Gatti, G; Cavallo, R; Sartori, M L; Carignola, R; Masera, R; Delponte, D; Salvadori, A; Angeli, A

    1988-01-01

    We searched for circadian changes in the enhancement of the NK activity after exposure to IFN-gamma of peripheral blood mononuclear (PBM) cells obtained serially throughout the 24-h cycle. In August-October 1986, blood was drawn from 7 healthy, diurnally active and nocturnally resting male volunteers (22-34 yr) at 4-h intervals for 24 h starting at 08:00. PBM cells were immediately separated and assayed for NK cell activity, using K 562 cultured cells as a target in a 4-h 51Cr release assay after prior incubation for 20 h with buffer or 300 IU rIFN-gamma. Circadian variations of the spontaneous NK cell cytotoxicity were apparent; the activity was at its maximum at the end of the night or in the early morning and then declined in the afternoon. The 24-h rhythmic pattern was validated with statistical significance by the Cosinor method (p less than 0.02; acrophase 04:22). Maximum enhancement by IFN-gamma was attained in the second part of the night or in the early morning, i.e. in phase with the peak of the spontaneous NK cell activity. A significant circadian rhythm of the percent increase above control levels was validated by the Cosinor method (p less than 0.01; acrophase 04:03). Our findings may be of relevance to a better understanding of the mechanisms of control of human NK activity and warrant consideration as an approach to improve the effectiveness of time-qualified immunotherapy.

  16. Variations in soil microbial community structure induced by the conversion from paddy fields to upland fields

    Science.gov (United States)

    Dai, X.

    2015-12-01

    Land-use conversion is an important factor influencing the carbon and nitrogen gas exchange between land and atmosphere, and soil microorganisms is main driver of soil carbon and nitrogen gas production. Understanding the effect of land-use conversion on soil microbial communities and its influencing factor is important for greenhouse gas emission reduction and soil organic carbon and nitrogen sequestration and stability. The influence of land use conversion on soil process was undergoing a dynamic change, but little research has been done to understand the effect on soil microbial communities during the initial years after land conversion. In the study, the influences of land-use conversion from double rice cropping (RR) to maize-maize (MM) and soybean-peanut (SP) double cropping systems on soil physical and chemical properties, and microbial community structure was studied after two years of the conversion in southern China. The results showed that land use conversion significantly changed soil properties, microbial communities and biomass. Soil pH significantly decreased by 0.50 and 0.52 after conversion to MM and SP, respectively. Soil TN and NH4-N also significantly decreased by 9%-15% and 60% after conversion to upland fields, respectively. The total PLFAs, bacterial, gram-positive bacterial (G+), gram-negative bacterial (G-) and actinomycetic PLFAs decreased significantly. The ng g-1 soil concentration of monounsaturated chain PLFAs 16:1ω7c and 18:1ω9t were significantly higher at paddy fields than at upland fields. No significant differences in soil properties, microbial communities and biomass were found between conversed MM and SP. Our results indicated that land use conversion, not crop type conversed had a significant effects on soil properties and microbial communities at the initial of land conversion. And soil pH was the key factor regulating the variations in soil microbial community structure after land use conversion from paddy to upland fields.

  17. Zonal migration and transport variations of the Kuroshio east of Taiwan induced by eddy impingements

    Science.gov (United States)

    Chang, Ming-Huei; Jan, Sen; Mensah, Vigan; Andres, Magdalena; Rainville, Luc; Yang, Yiing Jang; Cheng, Yu-Hsin

    2018-01-01

    Variability of the Kuroshio east of Taiwan was observed at a cross-stream transect 50 km south of the PCM-1 line with an array of three moored ADCPs measuring for 23 months, supplemented with eleven repeated shipboard surveys. Observations of the Kuroshio's velocity structure reveal the absence of an obvious regular seasonal signal, but significant variability at 70-200 day period for both maximum velocity axis migration and transport due to interactions with mesoscale eddies. Empirical orthogonal function (EOF) analysis shows the migration and transport modes explain 46% and 29% of the total variance, respectively, which is in contrast to the findings at the PCM-1 line where the transport mode explained more variance than did the migration mode. The Kuroshio transport in the upper 500 m across a 150 km section is 17.2 Sv with a standard deviation of 5 Sv. The estimated Kuroshio transport is 4.3 Sv lower than that reported for the PCM-1 line, likely due to the interannual variations related to abundance of mesoscale eddies in the Subtropical Counter Current (STCC) region. Transport variability east of Taiwan is mostly caused by Kuroshio-eddy interactions. When single anticyclonic (cyclonic) eddies encounter the Kuroshio, they enhance (reduce) poleward transport, presumably by increasing (decreasing) the sea level anomaly (SLA) along the eastern flank of the Kuroshio (correlation = 0.82). When a pair of eddies impinges on the Kuroshio, the upstream confluence and diffluence caused by the dipole eddies increases and decreases the Kuroshio transport, respectively. Furthermore, the eastward (westward) currents that result from either the single eddy or the dipole eddy produce flow divergence (convergence) adjacent to the Kuroshio's eastern edge, favoring the offshore (onshore) migration of the Kuroshio axis.

  18. Valence band variation in Si (110) nanowire induced by a covered insulator

    International Nuclear Information System (INIS)

    Hong-Hua, Xu; Xiao-Yan, Liu; Yu-Hui, He; Gang, Du; Ru-Qi, Han; Jin-Feng, Kang; Chun, Fan; Ai-Dong, Sun

    2010-01-01

    In this work, we investigate strain effects induced by the deposition of gate dielectrics on the valence band structures in Si (110) nanowire via the simulation of strain distribution and the calculation of a generalized 6×6k·p strained valence band. The nanowire is surrounded by the gate dielectric. Our simulation indicates that the strain of the amorphous SiO 2 insulator is negligible without considering temperature factors. On the other hand, the thermal residual strain in a nanowire with amorphous SiO 2 insulator which has negligible lattice misfit strain pushes the valence subbands upwards by chemical vapour deposition and downwards by thermal oxidation treatment. In contrast with the strain of the amorphous SiO 2 insulator, the strain of the HfO 2 gate insulator in Si (110) nanowire pushes the valence subbands upwards remarkably. The thermal residual strain by HfO 2 insulator contributes to the up-shifting tendency. Our simulation results for valence band shifting and warping in Si nanowires can provide useful guidance for further nanowire device design. (classical areas of phenomenology)

  19. Seeking sprite-induced signatures in remotely sensed middle atmosphere NO2: latitude and time variations

    International Nuclear Information System (INIS)

    Arnone, E; Carlotti, M; Papandrea, E; Ridolfi, M; Kero, A; Enell, C-F; Turunen, E; Rodger, Craig J; Arnold, N F; Dinelli, B M

    2009-01-01

    Recent research on sprites shows these and other transient luminous events can exert a local impact on atmospheric chemistry, although with minor effects at global scales. In particular, both modelling and remote sensing work suggest perturbations to the background NO x up to a few tens of per cent can occur above active sprite-producing thunderstorms. In this study we present a detailed investigation of MIPAS/ENVISAT satellite measurements of middle atmospheric NO 2 in regions of high likelihood of sprite occurrence during the period August to December 2003. As a proxy of sprite activity we used ground based WWLLN detections of large tropospheric thunderstorms. By investigating the sensitivity of the analysis to the characteristics of the adopted strategy, we confirm the indication of sprite-induced NO 2 enhancements of about 10% at 52 km height and tens of per cent at 60 km height immediately after thunderstorm activity, as previously reported by Arnone et al (2008b Geophys. Res. Lett. 35 5807). A further analysis showed the enhancement to be dominated by the contribution from regions north of the Equator (5 deg. N to 20 deg. N) during the first 30 to 40 days of the sample (i.e. the tail of Northern Hemisphere summer) and in coincidence with low background winds.

  20. componente vegetal

    Directory of Open Access Journals (Sweden)

    Fabio Moscovich

    2005-01-01

    Full Text Available In order to determine environmental impact, indicators based on vegetation characteristics that would generate the forestry monoculture with the adjacent native forest, 32 sample unit were installed in an area of LIPSIA private enterprise, Esperanza Department, Misiones with those characteristics. The plots of 100 m2 were distributed systematically every 25 meters. The vegetation was divided in stratum: superior (DBH ≥ 10 cm, middle (1,6 cm ≤ DBH > 10 cm and inferior (DBH< cm. There were installed 10 plots in a logged native forest, 10 plots in a 18 years old Pinus elliottii Engelm. with approximately 400 trees/ha., 6 plots in a 10 – 25 years old Araucaria angustifolia (Bertd. Kuntze limiting area with approximately 900 trees/ha., and 6 plots located in this plantation. In the studied area were identified 150 vegetation species. In the inferior stratum there were found differences as function of various floristic diversity indexes. In all the cases the native forest showed larger diversity than plantations, followed by Pinus elliottii, Araucaria plantation and Araucaria limiting area. All the studied forest fitted to a logarithmical series of species distributions, that would indicate the incidence of a environmental factor in this distribution.

  1. Sink limitation induces the expression of multiple soybean vegetative lipoxygenase mRNAs while the endogenous jasmonic acid level remains low.

    Science.gov (United States)

    Bunker, T W; Koetje, D S; Stephenson, L C; Creelman, R A; Mullet, J E; Grimes, H D

    1995-08-01

    The response of individual members of the lipoxygenase multigene family in soybeans to sink deprivation was analyzed. RNase protection assays indicated that a novel vegetative lipoxygenase gene, vlxC, and three other vegetative lipoxygenase mRNAs accumulated in mature leaves in response to a variety of sink limitations. These data suggest that several members of the lipoxygenase multigene family are involved in assimilate partitioning. The possible involvement of jasmonic acid as a signaling molecule regulating assimilate partitioning into the vegetative storage proteins and lipoxygenases was directly assessed by determining the endogenous level of jasmonic acid in leaves from plants with their pods removed. There was no rise in the level of endogenous jasmonic acid coincident with the strong increase in both vlxC and vegetative storage protein VspB transcripts in response to sink limitation. Thus, expression of the vegetative lipoxygenases and vegetative storage proteins is not regulated by jasmonic acid in sink-limited leaves.

  2. Social context-induced song variation affects female behavior and gene expression.

    Directory of Open Access Journals (Sweden)

    Sarah C Woolley

    2008-03-01

    Full Text Available Social cues modulate the performance of communicative behaviors in a range of species, including humans, and such changes can make the communication signal more salient. In songbirds, males use song to attract females, and song organization can differ depending on the audience to which a male sings. For example, male zebra finches (Taeniopygia guttata change their songs in subtle ways when singing to a female (directed song compared with when they sing in isolation (undirected song, and some of these changes depend on altered neural activity from a specialized forebrain-basal ganglia circuit, the anterior forebrain pathway (AFP. In particular, variable activity in the AFP during undirected song is thought to actively enable syllable variability, whereas the lower and less-variable AFP firing during directed singing is associated with more stereotyped song. Consequently, directed song has been suggested to reflect a "performance" state, and undirected song a form of vocal motor "exploration." However, this hypothesis predicts that directed-undirected song differences, despite their subtlety, should matter to female zebra finches, which is a question that has not been investigated. We tested female preferences for this natural variation in song in a behavioral approach assay, and we found that both mated and socially naive females could discriminate between directed and undirected song-and strongly preferred directed song. These preferences, which appeared to reflect attention especially to aspects of song variability controlled by the AFP, were enhanced by experience, as they were strongest for mated females responding to their mate's directed songs. We then measured neural activity using expression of the immediate early gene product ZENK, and found that social context and song familiarity differentially modulated the number of ZENK-expressing cells in telencephalic auditory areas. Specifically, the number of ZENK-expressing cells in the

  3. Fabrication-process-induced variations of Nb/Al/AlOx/Nb Josephson junctions in superconductor integrated circuits

    International Nuclear Information System (INIS)

    Tolpygo, Sergey K; Amparo, Denis

    2010-01-01

    Currently, superconductor digital integrated circuits fabricated at HYPRES, Inc. can operate at clock frequencies approaching 40 GHz. The circuits present multilayered structures containing tens of thousands of Nb/Al/AlO x /Nb Josephson junctions (JJs) of various sizes interconnected by four Nb wiring layers, resistors, and other circuit elements. In order to be fully operational, the integrated circuits should be fabricated such that the critical currents of the JJs are within the tight design margins and the proper relationships between the critical currents of JJs of different sizes are preserved. We present experimental data and discuss mechanisms of process-induced variations of the critical current and energy gap of Nb/Al/AlO x /Nb JJs in integrated circuits. We demonstrate that the Josephson critical current may depend on the type and area of circuit elements connected to the junction, on the circuit pattern, and on the step in the fabrication process at which the connection is made. In particular, we discuss the influence of (a) the junction base electrode connection to the ground plane, (b) the junction counter electrode connection to the ground plane, and (c) the counter electrode connection to the Ti/Au or Ti/Pd/Au contact pads by Nb wiring. We show that the process-induced changes of the properties of Nb/Al/AlO x /Nb junctions are caused by migration of impurity atoms (hydrogen) between the different layers comprising the integrated circuits.

  4. The 2010 Russian Drought Impact on Satellite Measurements of Solar-Induced Chlorophyll Fluorescence: Insights from Modeling and Comparisons with the Normalized Differential Vegetation Index (NDVI)

    Science.gov (United States)

    Yoshida, Y.; Joiner, J.; Tucker, C.; Berry, J.; Lee, J. -E.; Walker, G.; Reichle, R.; Koster, R.; Lyapustin, A.; Wang, Y.

    2015-01-01

    We examine satellite-based measurements of chlorophyll solar-induced fluorescence (SIF) over the region impacted by the Russian drought and heat wave of 2010. Like the popular Normalized Difference Vegetation Index (NDVI) that has been used for decades to measure photosynthetic capacity, SIF measurements are sensitive to the fraction of absorbed photosynthetically-active radiation (fPAR). However, in addition, SIF is sensitive to the fluorescence yield that is related to the photosynthetic yield. Both SIF and NDVI from satellite data show drought-related declines early in the growing season in 2010 as compared to other years between 2007 and 2013 for areas dominated by crops and grasslands. This suggests an early manifestation of the dry conditions on fPAR. We also simulated SIF using a global land surface model driven by observation-based meteorological fields. The model provides a reasonable simulation of the drought and heat impacts on SIF in terms of the timing and spatial extents of anomalies, but there are some differences between modeled and observed SIF. The model may potentially be improved through data assimilation or parameter estimation using satellite observations of SIF (as well as NDVI). The model simulations also offer the opportunity to examine separately the different components of the SIF signal and relationships with Gross Primary Productivity (GPP).

  5. Exposure-dependent variation in cryolite induced lethality in the nontarget insect, Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Podder Sayanti

    2014-03-01

    Full Text Available The starting point of toxicity testing of any chemical in an organism is the determination of its Lethal Concentration 50 (LC50. In the present study, LC50 of a fluorinated insecticide cryolite is determined in a non-target insect model, Drosophila melanogaster. Interestingly, the result shows that acute LC50 of cryolite was much greater in comparison to the chronic one in case of Drosophila larvae. Larvae which were exposed to 65,000 to 70,000 μg/ml cryolite through food showed 50% mortality after 18 hours of acute exposure, whereas only 150 to 160 μg/ml cryolite was sufficient to cause 50% mortality in case of chronic exposure. Thus cryolite in a small amount when applied once cannot produce noticeable changes in Drosophila, whereas the same amount when used continuously can be fatal. The non-feeding pupal stage was also seen to be affected by chemical treatment. This suggests that the test chemical affects the developmental fate and results in failure of adult emergence. Absence of chemical-induced mortality in adults assumes that the toxicity of cryolite might be restricted to the preimaginal stages of the organism. Reduction in body size of larvae after ingestion of cryolite (with food in acute treatment schedule is another interesting finding of this study. Some individuals consuming cryolite containing food cannot survive whereas the few survivors manifest a significant growth retardation which might be due to a tendency of refusal in feeding. Hence the present findings provide a scope of assessment of risk of other similar non-target groups

  6. Dopant induced variations in microstructure and optical properties of CeO2 nanoparticles

    International Nuclear Information System (INIS)

    Mohanty, Bhaskar Chandra; Lee, Jong Won; Yeon, Deuk-Ho; Jo, Yeon-Hwa; Kim, Jong Hak; Cho, Yong Soo

    2011-01-01

    Research highlights: → Dopant (Zr 4+ , La 3+ , and Ca 2+ ) induced phase stability, and changes in microstructure and optical properties of CeO 2 nanoparticles have been studied. → The nanoparticles were prepared by hydrothermal synthesis of nitrate solutions. → The results show modification of the unit cell parameter by -0.39, +0.83 and +0.16% for doping of 20% Zr 4+ , La 3+ , and Ca 2+ , respectively. → For each batch prepared, nanoparticles with a narrow size distribution of 5-15 nm have been obtained. These particles are single crystals mostly having polygonal two-dimensional projections. → UV-visible spectra of doped particles exhibit shift of the absorption edge and absorption peak with respect to those of the undoped ones and has been attributed to compensation of Ce 3+ and decreasing crystallite size as result of doping. -- Abstract: Nanocrystalline CeO 2 particles doped in the range of 0-20% of Ca 2+ , La 3+ , and Zr 4+ have been prepared from hydrothermal synthesis of nitrate solutions at 200 o C and the influences of the dopants on microstructure and optical properties of the nanoparticles have been investigated. The unit cell parameter is found to be modified by -0.39, +0.83 and +0.16% for doping of 20% Zr 4+ , La 3+ , and Ca 2+ , respectively. For each batch prepared, nanoparticles with a narrow size distribution of 5-15 nm have been obtained. A high-resolution transmission electron microscopy investigation reveals that these particles are single crystals mostly having hexagonal, square or circular two-dimensional projections. UV-visible spectra of doped powders exhibit shift of the absorption edge and absorption peak with respect to those of the undoped CeO 2 particles and has been attributed to compensation of Ce 3+ and decreasing crystallite size as result of doping.

  7. Variation in yield gap induced by nitrogen, phosphorus and potassium fertilizer in North China Plain.

    Directory of Open Access Journals (Sweden)

    Xiaoqin Dai

    Full Text Available A field experiment was conducted under a wheat-maize rotation system from 1990 to 2006 in North China Plain (NCP to determine the effects of N, P and K on yield and yield gap. There were five treatments: NPK, PK, NK, NP and a control. Average wheat and maize yields were the highest in the NPK treatment, followed by those in the NP plots among all treatments. For wheat and maize yield, a significant increasing trend over time was found in the NPK-treated plots and a decreasing trend in the NK-treated plots. In the absence of N or P, wheat and maize yields were significantly lower than those in the NPK treatment. For both crops, the increasing rate of the yield gap was the highest in the P omission plots, i.e., 189.1 kg ha(-1 yr(-1 for wheat and 560.6 kg ha(-1 yr(-1 for maize. The cumulative omission of P fertilizer induced a deficit in the soil available N and extractable P concentrations for maize. The P fertilizer was more pivotal in long-term wheat and maize growth and soil fertility conservation in NCP, although the N fertilizer input was important for both crops growth. The crop response to K fertilizers was much lower than that to N or P fertilizers, but for maize, the cumulative omission of K fertilizer decreased the yield by 26% and increased the yield gap at a rate of 322.7 kg ha(-1 yr(-1. The soil indigenous K supply was not sufficiently high to meet maize K requirement over a long period. The proper application of K fertilizers is necessary for maize production in the region. Thus, the appropriate application of N and P fertilizers for the growth of both crops, while regularly combining K fertilizers for maize growth, is absolutely necessary for sustainable crop production in the NCP.

  8. Variation in yield gap induced by nitrogen, phosphorus and potassium fertilizer in North China Plain.

    Science.gov (United States)

    Dai, Xiaoqin; Ouyang, Zhu; Li, Yunsheng; Wang, Huimin

    2013-01-01

    A field experiment was conducted under a wheat-maize rotation system from 1990 to 2006 in North China Plain (NCP) to determine the effects of N, P and K on yield and yield gap. There were five treatments: NPK, PK, NK, NP and a control. Average wheat and maize yields were the highest in the NPK treatment, followed by those in the NP plots among all treatments. For wheat and maize yield, a significant increasing trend over time was found in the NPK-treated plots and a decreasing trend in the NK-treated plots. In the absence of N or P, wheat and maize yields were significantly lower than those in the NPK treatment. For both crops, the increasing rate of the yield gap was the highest in the P omission plots, i.e., 189.1 kg ha(-1) yr(-1) for wheat and 560.6 kg ha(-1) yr(-1) for maize. The cumulative omission of P fertilizer induced a deficit in the soil available N and extractable P concentrations for maize. The P fertilizer was more pivotal in long-term wheat and maize growth and soil fertility conservation in NCP, although the N fertilizer input was important for both crops growth. The crop response to K fertilizers was much lower than that to N or P fertilizers, but for maize, the cumulative omission of K fertilizer decreased the yield by 26% and increased the yield gap at a rate of 322.7 kg ha(-1) yr(-1). The soil indigenous K supply was not sufficiently high to meet maize K requirement over a long period. The proper application of K fertilizers is necessary for maize production in the region. Thus, the appropriate application of N and P fertilizers for the growth of both crops, while regularly combining K fertilizers for maize growth, is absolutely necessary for sustainable crop production in the NCP.

  9. Variation in antibiotic-induced microbial recolonization impacts on the host metabolic phenotypes of rats.

    Science.gov (United States)

    Swann, Jonathan R; Tuohy, Kieran M; Lindfors, Peter; Brown, Duncan T; Gibson, Glenn R; Wilson, Ian D; Sidaway, James; Nicholson, Jeremy K; Holmes, Elaine

    2011-08-05

    The interaction between the gut microbiota and their mammalian host is known to have far-reaching consequences with respect to metabolism and health. We investigated the effects of eight days of oral antibiotic exposure (penicillin and streptomycin sulfate) on gut microbial composition and host metabolic phenotype in male Han-Wistar rats (n = 6) compared to matched controls. Early recolonization was assessed in a third group exposed to antibiotics for four days followed by four days recovery (n = 6). Fluorescence in situ hybridization analysis of the intestinal contents collected at eight days showed a significant reduction in all bacterial groups measured (control, 10(10.7) cells/g feces; antibiotic-treated, 10(8.4)). Bacterial suppression reduced the excretion of mammalian-microbial urinary cometabolites including hippurate, phenylpropionic acid, phenylacetylglycine and indoxyl-sulfate whereas taurine, glycine, citrate, 2-oxoglutarate, and fumarate excretion was elevated. While total bacterial counts remained notably lower in the recolonized animals (10(9.1) cells/g faeces) compared to the controls, two cage-dependent subgroups emerged with Lactobacillus/Enterococcus probe counts dominant in one subgroup. This dichotomous profile manifested in the metabolic phenotypes with subgroup differences in tricarboxylic acid cycle metabolites and indoxyl-sulfate excretion. Fecal short chain fatty acids were diminished in all treated animals. Antibiotic treatment induced a profound effect on the microbiome structure, which was reflected in the metabotype. Moreover, the recolonization process was sensitive to the microenvironment, which may impact on understanding downstream consequences of antibiotic consumption in human populations.

  10. Participation of intracellular and extracellular pH changes in photosynthetic response development induced by variation potential in pumpkin seedlings.

    Science.gov (United States)

    Sherstneva, O N; Vodeneev, V A; Katicheva, L A; Surova, L M; Sukhov, V S

    2015-06-01

    Electrical signals presented in plants by action potential and by variation potential (VP) can induce a reversible inactivation of photosynthesis. Changes in the intracellular and extracellular pH during VP generation are a potential mechanism of photosynthetic response induction; however, this hypothesis requires additional experimental investigation. The purpose of the present work was to analyze the influence of pH changes on induction of the photosynthetic response in pumpkin. It was shown that a burning of the cotyledon induced VP propagation into true leaves of pumpkin seedlings inducing a decrease in the photosynthetic CO2 assimilation and an increase in non-photochemical quenching of fluorescence, whereas respiration was activated insignificantly. The photosynthetic response magnitude depended linearly on the VP amplitude. The intracellular and extracellular concentrations of protons were analyzed using pH-sensitive fluorescent probes, and the VP generation was shown to be accompanied by apoplast alkalization (0.4 pH unit) and cytoplasm acidification (0.3 pH unit). The influence of changes in the incubation medium pH on the non-photochemical quenching of fluorescence of isolated chloroplasts was also investigated. It was found that acidification of the medium stimulated the non-photochemical quenching, and the magnitude of this increase depended on the decrease in pH. Our results confirm the contribution of changes in intracellular and extracellular pH to induction of the photosynthetic response caused by VP. Possible mechanisms of the influence of pH changes on photosynthesis are discussed.

  11. Vegetation-induced soil water repellency as a strategy in arid ecosystems. A geochemical approach in Banksia woodlands (SW Australia)

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Jiménez-Morillo, Nicasio T.; González-Pérez, Jose Antonio; Zavala, Lorena M.; Stevens, Jason; Jordan, Antonio

    2016-04-01

    Introduction Banksia woodlands (BW) are iconic ecosystems of Western Australia (WA) composed by an overstorey dominated by Proteaceae, e.g. Banksia menziesii and Banksia attenuata, in combination with other species, such as Eucalyptus spp., Verticordia spp. or Melaleuca spp. Although located in very poor dune soils, BW provide numerous ecosystem services and sustain a high biodiversity. In this area, annual rainfall is relatively high (about 800 mm) but permeability of the sandy substrate leads to a functionally arid ecosystem. Currently, BW are threatened by sand mining activities and urban expansion; therefore conservation and restoration of these woodlands are critical. Despite numerous efforts, the success of restoration plans is usually poor mostly due to the high sensitivity to drought stress and poor seedling survival rates (5-30%) (Benigno et al., 2014). A characteristic feature of BW is their root architecture, formed by a proteoid (cluster) system that spreads to form thick mats below the soil surface, favouring the uptake of nutrients (especially, P), and preventing soil erosion. Root exudates are related to numerous plant functions, as they facilitate penetration of roots in soil and enhance the extraction of scarce mineral nutrients and its further assimilation. Exudates may also interact directly with soil or indirectly through microbial mediated events being also related to soil water repellency (SWR; Lozano et al, 2014). Knowledge about the specific compounds able to induce SWR is limited (Doerr et al., 2000), but it is generally accepted that is caused by organic molecules coating the surface of soil mineral particles and aggregates (Jordán et al., 2013). Proteaceae release short-chained organic acids to enhance phosphate acquisition, which have been also reported to be related with SWR (Jiménez-Morillo et al., 2014). It is hypothesized that disruption of water dynamics in mature BW soils is underlying the failure of restoration plans. This

  12. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    Science.gov (United States)

    Miller, David A.; Vleck, Carol M.; Otis, David L.

    2009-01-01

    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  13. African indigenous and traditional vegetables in Tanzania ...

    African Journals Online (AJOL)

    Indigenous and traditional African vegetables (AITVs) are important sources of ... and (iii) marketing: retail markup, price variation by season, year and region, ... size and cost, retailer storage, remainders, processing and less common AITVs.

  14. Change in diurnal variations of meteorological variables induced by anthropogenic aerosols over the North China Plain in summer 2008

    Science.gov (United States)

    Gao, Yi; Zhang, Meigen; Liu, Xiaohong; Wang, Lili

    2016-04-01

    This study investigates the impacts of all anthropogenic aerosols and anthropogenic black carbon (BC) on the diurnal variations of meteorological variables in the atmospheric boundary layer over the North China Plain (NCP) during June to August 2008, using a coupled meteorology and chemistry model (WRF-Chem). The results of the ensemble numerical experiments show that surface air temperature decreases by about 0.6 to 1.2 K with the maximum decrease over the Beijing urban area and the southern part of Hebei province, and the surface relative humidity (RH) increases by 2-4 % owing to all anthropogenic aerosols. On the contrary, anthropogenic BC induces a small change of temperature and RH at surface. Averaged for Beijing, Tianjin, and Hebei province (BTH region) and High Particle Concentration (HPC) periods when PM2.5 surface concentration is more than 60 μg m-3 and daily AOD is more than 0.9, all anthropogenic aerosols decrease air temperature under 850 hPa and increase it between 500 and 850 hPa, while anthropogenic BC increases it for whole atmosphere. The maximum changes occur at 08:00-20:00 (local time). Aerosol-induced surface energy and diabatic heating change leads to a cooling at the surface and in the lower atmosphere and a warming in the middle troposphere at 08:00-17:00, with reversed effects at 20:00-05:00. BC cools the atmosphere at the surface and warms the atmosphere above for the whole day. As a result, the equivalent potential temperature profile change shows that the lower atmosphere is more stable at 08:00 and 14:00. All anthropogenic aerosols decrease the surface wind speed by 20-60 %, while anthropogenic BC decreases the wind speed by 10-40 % over the NCP with the maximum decrease at 08:00. The aerosol-induced stabilization of the lower atmosphere favors the accumulation of air pollutants and thus contributes to deterioration of visibility and fog-haze events.

  15. Final technical report for Phenomic Analysis of Natural and Induced Variation in Brachypodium Distachyon DE-SC0001526

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, John P. [USDA ARS Western Regional Research Center, Albany, NY (United States)

    2014-12-17

    The goal of this project was to apply high-throughput, non-destructive phenotyping (phenomics) to collections of natural variants and induced mutants of the model grass Brachypodium distachyon and characterize a small subset of that material in detail. B. distachyon is well suited to this phenomic approach because its small size and rapid generation time allow researchers to grow many plants under carefully controlled conditions. In addition, the simple diploid genetics, high quality genome sequence and existence of numerous experimental tools available for B. distachyon allow us to rapidly identify genes affecting specific phenotypes. Our phenomic analysis revealed great diversity in biofuel-relevant traits like growth rate, biomass and photosynthetic rate. This clearly demonstrated the feasibility of applying a phenomic approach to the model grass B. distachyon. We also demonstrated the utility of B. distachyon for studying mature root system, something that is virtually impossible to do with biomass crops. We showed tremendous natural variation in root architecture that can potentially be used to design crops with superior nutrient and water harvesting capability. Finally, we demonstrated the speed with which we can link specific genes to specific phenotypes by studying two mutants in detail. Importantly, in both cases, the specific biological lessons learned were grass-specific and could not have been learned from a dicot model system. Furthermore, one of the genes affects cell wall integrity and thus may be a useful target in the context of biomass crop improvement. Ultimately, all this information can be used to accelerate the creation of improved biomass crops.

  16. Time-delay-induced dynamical behaviors for an ecological vegetation growth system driven by cross-correlated multiplicative and additive noises.

    Science.gov (United States)

    Wang, Kang-Kang; Ye, Hui; Wang, Ya-Jun; Li, Sheng-Hong

    2018-05-14

    In this paper, the modified potential function, the stationary probability distribution function (SPDF), the mean growth time and the mean degeneration time for a vegetation growth system with time delay are investigated, where the vegetation system is assumed to be disturbed by cross-correlated multiplicative and additive noises. The results reveal some fact that the multiplicative and additive noises can both reduce the stability and speed up the decline of the vegetation system, while the strength of the noise correlation and time delay can both enhance the stability of the vegetation and slow down the depression process of the ecological system. On the other hand, with regard to the impacts of noises and time delay on the mean development and degeneration processes of the ecological system, it is discovered that 1) in the development process of the vegetation population, the increase of the noise correlation strength and time delay will restrain the regime shift from the barren state to the boom one, while the increase of the additive noise can lead to the fast regime shift from the barren state to the boom one. 2) Conversely, in the depression process of the ecological system, the increase of the strength of the correlation noise and time delay will prevent the regime shift from the boom state to the barren one. Comparatively, the increase of the additive and multiplicative noises can accelerate the regime shift from the boom state to the barren state.

  17. Temporal reflectance changes in vegetables

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  18. Formation of banded vegetation patterns resulted from interactions between sediment deposition and vegetation growth.

    Science.gov (United States)

    Huang, Tousheng; Zhang, Huayong; Dai, Liming; Cong, Xuebing; Ma, Shengnan

    2018-03-01

    This research investigates the formation of banded vegetation patterns on hillslopes affected by interactions between sediment deposition and vegetation growth. The following two perspectives in the formation of these patterns are taken into consideration: (a) increased sediment deposition from plant interception, and (b) reduced plant biomass caused by sediment accumulation. A spatial model is proposed to describe how the interactions between sediment deposition and vegetation growth promote self-organization of banded vegetation patterns. Based on theoretical and numerical analyses of the proposed spatial model, vegetation bands can result from a Turing instability mechanism. The banded vegetation patterns obtained in this research resemble patterns reported in the literature. Moreover, measured by sediment dynamics, the variation of hillslope landform can be described. The model predicts how treads on hillslopes evolve with the banded patterns. Thus, we provide a quantitative interpretation for coevolution of vegetation patterns and landforms under effects of sediment redistribution. Copyright © 2018. Published by Elsevier Masson SAS.

  19. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  20. Heat-induced formation of mepiquat by decarboxylation of pipecolic acid and its betaine derivative. Part 2: Natural formation in cooked vegetables and selected food products.

    Science.gov (United States)

    Yuan, Yuan; Tarres, Adrienne; Bessaire, Thomas; Rademacher, Wilhelm; Stadler, Richard H; Delatour, Thierry

    2017-08-01

    Mepiquat (N,N-dimethylpiperidinium) is a plant growth regulator registered for use as its chloride salt in many countries on cereals and other crops. Recent model system studies have shown that natural chemicals present in crop plants, such as pipecolic acid and pipecolic acid betaine, may furnish mepiquat through different chemical pathways, when subjected to temperatures in the range of 200°C. In this study, we cooked raw vegetables that did not contain mepiquat to a palatable state using different traditional cooking methods, and detected mepiquat in 9 out of 11 oven-cooked vegetables, reaching up to 189μg/kg dry wt in oven-cooked broccoli. Commercial oven potato fries generated mepiquat during cooking, typically in the range of 20-60μg/kg. Only traces of mepiquat (cooked vegetables, including potatoes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Mutation breeding in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Takashi

    1984-03-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting this situation, the demand for breeding is diversified and characteristic. The present status of mutation breeding of vegetables is not yet well under way, but reports of about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation are compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. Results obtained in Japan include: burdocks as an example to gamma ray irradiation of seeds; tomatoes as an example of inducing compound resistance against disease injury; and lettuce as an example of internal beta irradiation. (Kako, I.).

  2. Mutation breeding in vegetable crops

    International Nuclear Information System (INIS)

    Yamaguchi, Takashi

    1984-01-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting the situation like this, the demand for breeding is diversified and characteristic, and the case of applying mutation breeding seems to be many. The present status of the mutation breeding of vegetables is not yet well under way, but about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation were compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. As the results obtained in Japan, burdocks as an example of gamma ray irradiation to seeds, tomatoes as an example of inducing the compound resistance against disease injury and lettuces as an example of internal beta irradiation are reported. (Kako, I.)

  3. Mass-induced sea level variations in the Red Sea from GRACE, steric-corrected altimetry, in situ bottom pressure records, and hydrographic observations

    Science.gov (United States)

    Feng, W.; Lemoine, J.-M.; Zhong, M.; Hsu, H. T.

    2014-08-01

    An annual amplitude of ∼18 cm mass-induced sea level variations (SLV) in the Red Sea is detected from the Gravity Recovery and Climate Experiment (GRACE) satellites and steric-corrected altimetry from 2003 to 2011. The annual mass variations in the region dominate the mean SLV, and generally reach maximum in late January/early February. The annual steric component of the mean SLV is relatively small (mass-induced SLV. In situ bottom pressure records at the eastern coast of the Red Sea validate the high mass variability observed by steric-corrected altimetry and GRACE. In addition, the horizontal water mass flux of the Red Sea estimated from GRACE and steric-corrected altimetry is validated by hydrographic observations.

  4. A test of genotypic variation in specificity of herbivore-induced responses in Solidago altissima L. (Asteraceae)

    NARCIS (Netherlands)

    Uesugi, A.; Poelman, E.H.; Kessler, A.

    2013-01-01

    Plant-induced responses to multiple herbivores can mediate ecological interactions among herbivore species, thereby influencing herbivore community composition in nature. Several studies have indicated high specificity of induced responses to different herbivore species. In addition, there may be

  5. Genetic improvement of vegetables

    International Nuclear Information System (INIS)

    Jaramillo Vasquez, J.G.

    2001-01-01

    Some genetic bases of the improvement of vegetables are given. The objectives of the genetic improvement and the fundamental stages of this process are done. The sources of genetic variation are indicated and they are related the reproduction systems of the main horticultural species. It is analyzed the concept of genetic inheritance like base to determine the procedures more appropriate of improvement. The approaches are discussed, has more than enough phenotypic value, genetic action and genotypic variance; Equally the heredability concepts and value of improvement. The conventional methods of improvement are described, like they are: the introduction of species or varieties, the selection, the pure line, the pedigree method, the selection for families, the recurrent selection, the selection for unique seed, the haploids method, the selection for heterosis and the synthetic varieties

  6. Earthquake induced variations in extrusion rate: A numerical modeling approach to the 2006 eruption of Merapi Volcano (Indonesia)

    Science.gov (United States)

    Carr, Brett B.; Clarke, Amanda B.; de'Michieli Vitturi, Mattia

    2018-01-01

    Extrusion rates during lava dome-building eruptions are variable and eruption sequences at these volcanoes generally have multiple phases. Merapi Volcano, Java, Indonesia, exemplifies this common style of activity. Merapi is one of Indonesia's most active volcanoes and during the 20th and early 21st centuries effusive activity has been characterized by long periods of very slow (work has suggested that the peak extrusion rates observed in early June were triggered by the earthquake through either dynamic stress-induced overpressure or the addition of CO2 due to decarbonation and gas escape from new fractures in the bedrock. We use the numerical model to test the feasibility of these proposed hypotheses and show that, in order to explain the observed change in extrusion rate, an increase of approximately 5-7 MPa in magma storage zone overpressure is required. We also find that the addition of ∼1000 ppm CO2 to some portion of the magma in the storage zone following the earthquake reduces water solubility such that gas exsolution is sufficient to generate the required overpressure. Thus, the proposed mechanism of CO2 addition is a viable explanation for the peak phase of the Merapi 2006 eruption. A time-series of extrusion rate shows a sudden increase three days following the earthquake. We explain this three-day delay by the combined time required for the effects of the earthquake and corresponding CO2 increase to develop in the magma storage system (1-2 days), and the time we calculate for the affected magma to ascend from storage zone to surface (40 h). The increased extrusion rate was sustained for 2-7 days before dissipating and returning to pre-earthquake levels. During this phase, we estimate that 3.5 million m3 DRE of magma was erupted along with 11 ktons of CO2. The final phase of the 2006 eruption was characterized by highly variable extrusion rates. We demonstrate that those changes were likely controlled by failure of the edifice that had been confining

  7. Kinetic study of phytotoxicity induced by foliar lead uptake for vegetables exposed to fine particles and implications for sustainable urban agriculture.

    Science.gov (United States)

    Xiong, TianTian; Austruy, Annabelle; Pierart, Antoine; Shahid, Muhammad; Schreck, Eva; Mombo, Stéphane; Dumat, Camille

    2016-08-01

    At the global scale, foliar metal transfer occurs for consumed vegetables cultivated in numerous urban or industrial areas with a polluted atmosphere. However, the kinetics of metal uptake, translocation and involved phytotoxicity was never jointly studied with vegetables exposed to micronic and sub-micronic particles (PM). Different leafy vegetables (lettuces and cabbages) cultivated in RHIZOtest® devices were, therefore, exposed in a greenhouse for 5, 10 and 15days to various PbO PM doses. The kinetics of transfer and phytotoxicity was assessed in relation to lead concentration and exposure duration. A significant Pb accumulation in leaves (up to 7392mg/kg dry weight (DW) in lettuce) with translocation to roots was observed. Lead foliar exposure resulted in significant phytotoxicity, lipid composition change, a decrease of plant shoot growth (up to 68.2% in lettuce) and net photosynthesis (up to 58% in lettuce). The phytotoxicity results indicated plant adaptation to Pb and a higher sensitivity of lettuce in comparison with cabbage. Air quality needs, therefore, to be considered for the health and quality of vegetables grown in polluted areas, such as certain megacities (in China, Pakistan, Europe, etc.) and furthermore, to assess the health risks associated with their consumption. Copyright © 2016. Published by Elsevier B.V.

  8. Integration of Landscape Metrics and Variograms to Characterize and Quantify the Spatial Heterogeneity Change of Vegetation Induced by the 2008 Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2017-06-01

    Full Text Available The quantification of spatial heterogeneity can be used to examine the structure of ecological systems. The 2008 Wenchuan earthquake caused severe vegetation damage. In addition to simply detecting change, the magnitude of changes must also be examined. Remote sensing and geographic information system techniques were used to produce landscape maps before and after the earthquake and analyze the spatial-temporal change of the vegetation pattern. Landscape metrics were selected to quantify the spatial heterogeneity in a categorical map at both the class and landscape levels. The results reveal that the Wenchuan earthquake greatly increased the heterogeneity in the study area. In particular, forests experienced the most fragmentation among all of the landscape types. In addition, spatial heterogeneity in a numerical map was studied by using variogram analysis of normalized difference vegetation indices derived from Landsat images. In comparison to before the earthquake, the spatial variability after the earthquake had doubled. The structure of the spatial heterogeneity represented by the range of normalized difference vegetation index (NDVI variograms also changed due to the earthquake. Moreover, the results of the NDVI variogram analysis of three contrasting landscapes, which were farmland, broadleaved forest, and coniferous forest, confirm that the earthquake produced spatial variability and changed the structure of the landscapes. Regardless of before or after the earthquake, farmland sites are the most heterogeneous among the three landscapes studied.

  9. East African Cenozoic vegetation history.

    Science.gov (United States)

    Linder, Hans Peter

    2017-11-01

    The modern vegetation of East Africa is a complex mosaic of rainforest patches; small islands of tropic-alpine vegetation; extensive savannas, ranging from almost pure grassland to wooded savannas; thickets; and montane grassland and forest. Here I trace the evolution of these vegetation types through the Cenozoic. Paleogene East Africa was most likely geomorphologically subdued and, as the few Eocene fossil sites suggest, a woodland in a seasonal climate. Woodland rather than rainforest may well have been the regional vegetation. Mountain building started with the Oligocene trap lava flows in Ethiopia, on which rainforest developed, with little evidence of grass and none of montane forests. The uplift of the East African Plateau took place during the middle Miocene. Fossil sites indicate the presence of rainforest, montane forest and thicket, and wooded grassland, often in close juxtaposition, from 17 to 10 Ma. By 10 Ma, marine deposits indicate extensive grassland in the region and isotope analysis indicates that this was a C 3 grassland. In the later Miocene rifting, first of the western Albertine Rift and then of the eastern Gregory Rift, added to the complexity of the environment. The building of the high strato-volcanos during the later Mio-Pliocene added environments suitable for tropic-alpine vegetation. During this time, the C 3 grassland was replaced by C 4 savannas, although overall the extent of grassland was reduced from the mid-Miocene high to the current low level. Lake-level fluctuations during the Quaternary indicate substantial variation in rainfall, presumably as a result of movements in the intertropical convergence zone and the Congo air boundary, but the impact of these fluctuations on the vegetation is still speculative. I argue that, overall, there was an increase in the complexity of East African vegetation complexity during the Neogene, largely as a result of orogeny. The impact of Quaternary climatic fluctuation is still poorly understood

  10. [Effects of road construction on regional vegetation types].

    Science.gov (United States)

    Liu, Shi-Liang; Liu, Qi; Wang, Cong; Yang, Jue-Jie; Deng, Li

    2013-05-01

    As a regional artificial disturbance component, road exerts great effects on vegetation types, and plays a substantial role in defining vegetation distribution to a certain extent. Aiming at the tropical rainforest degradation and artificial forest expansion in Yunnan Province of Southwest China, this paper analyzed the effects of road network extension on regional vegetation types. In the Province, different classes of roads had different effects on the vegetation types, but no obvious regularity was observed in the effects on the patch areas of different vegetation types due to the great variations of road length and affected distance. However, the vegetation patch number was more affected by lower class roads because of their wide distribution. As for different vegetation types, the vegetations on cultivated land were most affected by roads, followed by Castanopsis hystrix and Schima wallichii forests. Road network formation contributed most to the vegetation fragmentation, and there existed significant correlations between the human disturbance factors including village- and road distributions.

  11. Evaluation of the standard normal variate method for Laser-Induced Breakdown Spectroscopy data treatment applied to the discrimination of painting layers

    Science.gov (United States)

    Syvilay, D.; Wilkie-Chancellier, N.; Trichereau, B.; Texier, A.; Martinez, L.; Serfaty, S.; Detalle, V.

    2015-12-01

    Nowadays, Laser-Induced Breakdown Spectroscopy (LIBS) is frequently used for in situ analyses to identify pigments from mural paintings. Nonetheless, in situ analyses require a robust instrumentation in order to face to hard experimental conditions. This may imply variation of fluencies and thus inducing variation of LIBS signal, which degrades spectra and then results. Usually, to overcome these experimental errors, LIBS signal is processed. Signal processing methods most commonly used are the baseline subtraction and the normalization by using a spectral line. However, the latter suggests that this chosen element is a constant component of the material, which may not be the case in paint layers organized in stratigraphic layers. For this reason, it is sometimes difficult to apply this normalization. In this study, another normalization will be carried out to throw off these signal variations. Standard normal variate (SNV) is a normalization designed for these conditions. It is sometimes implemented in Diffuse Reflectance Infrared Fourier Transform Spectroscopy and in Raman Spectroscopy but rarely in LIBS. The SNV transformation is not newly applied on LIBS data, but for the first time the effect of SNV on LIBS spectra was evaluated in details (energy of laser, shot by shot, quantification). The aim of this paper is the quick visualization of the different layers of a stratigraphic painting sample by simple data representations (3D or 2D) after SNV normalization. In this investigation, we showed the potential power of SNV transformation to overcome undesired LIBS signal variations but also its limit of application. This method appears as a promising way to normalize LIBS data, which may be interesting for in-situ depth analyses.

  12. Radar for Measuring Soil Moisture Under Vegetation

    Science.gov (United States)

    Moghaddam, Mahta; Moller, Delwyn; Rodriguez, Ernesto; Rahmat-Samii, Yahya

    2004-01-01

    A two-frequency, polarimetric, spaceborne synthetic-aperture radar (SAR) system has been proposed for measuring the moisture content of soil as a function of depth, even in the presence of overlying vegetation. These measurements are needed because data on soil moisture under vegetation canopies are not available now and are necessary for completing mathematical models of global energy and water balance with major implications for global variations in weather and climate.

  13. Sensitivity analysis of a coupled hydrodynamic-vegetation model using the effectively subsampled quadratures method (ESQM v5.2)

    Science.gov (United States)

    Kalra, Tarandeep S.; Aretxabaleta, Alfredo; Seshadri, Pranay; Ganju, Neil K.; Beudin, Alexis

    2017-12-01

    Coastal hydrodynamics can be greatly affected by the presence of submerged aquatic vegetation. The effect of vegetation has been incorporated into the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system. The vegetation implementation includes the plant-induced three-dimensional drag, in-canopy wave-induced streaming, and the production of turbulent kinetic energy by the presence of vegetation. In this study, we evaluate the sensitivity of the flow and wave dynamics to vegetation parameters using Sobol' indices and a least squares polynomial approach referred to as the Effective Quadratures method. This method reduces the number of simulations needed for evaluating Sobol' indices and provides a robust, practical, and efficient approach for the parameter sensitivity analysis. The evaluation of Sobol' indices shows that kinetic energy, turbulent kinetic energy, and water level changes are affected by plant stem density, height, and, to a lesser degree, diameter. Wave dissipation is mostly dependent on the variation in plant stem density. Performing sensitivity analyses for the vegetation module in COAWST provides guidance to optimize efforts and reduce exploration of parameter space for future observational and modeling work.

  14. Sensitivity analysis of a coupled hydrodynamic-vegetation model using the effectively subsampled quadratures method (ESQM v5.2

    Directory of Open Access Journals (Sweden)

    T. S. Kalra

    2017-12-01

    Full Text Available Coastal hydrodynamics can be greatly affected by the presence of submerged aquatic vegetation. The effect of vegetation has been incorporated into the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST modeling system. The vegetation implementation includes the plant-induced three-dimensional drag, in-canopy wave-induced streaming, and the production of turbulent kinetic energy by the presence of vegetation. In this study, we evaluate the sensitivity of the flow and wave dynamics to vegetation parameters using Sobol' indices and a least squares polynomial approach referred to as the Effective Quadratures method. This method reduces the number of simulations needed for evaluating Sobol' indices and provides a robust, practical, and efficient approach for the parameter sensitivity analysis. The evaluation of Sobol' indices shows that kinetic energy, turbulent kinetic energy, and water level changes are affected by plant stem density, height, and, to a lesser degree, diameter. Wave dissipation is mostly dependent on the variation in plant stem density. Performing sensitivity analyses for the vegetation module in COAWST provides guidance to optimize efforts and reduce exploration of parameter space for future observational and modeling work.

  15. Mass-induced sea level variations in the Red Sea from steric-corrected altimetry, GRACE, in-situ bottom pressure records, and hydrographic observations

    Science.gov (United States)

    Feng, Wei; Lemoine, Jean-Michel; Zhong, Min; Xu, Houze

    2014-05-01

    An annual amplitude of ~18 cm mass-induced sea level variations (SLV) in the Red Sea is detected from steric-corrected altimetry and the Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 to 2011, which dominates the mean sea level in the region. Seawater mass variations here generally reach maximum in late January/early February. The steric component of SLV calculated from oceanographic temperature and salinity data is relatively small and peaks about seven months later than mass variations. The phase difference between the steric SLV and the mass-induced SLV indicates that when the Red Sea gains the mass from inflow water in winter, the steric SLV fall, and vice versa in summer. In-situ bottom pressure records in the eastern coast of the Red Sea validate the high mass variability observed by steric-corrected altimetry and GRACE. Furthermore, we compare the horizontal water mass flux in the Red Sea from steric-corrected altimetry and GRACE with that estimated from hydrographic observations.

  16. A three-layer model of self-assembly induced surface-energy variation experimentally extracted by using nanomechanically sensitive cantilevers

    International Nuclear Information System (INIS)

    Zuo Guomin; Li Xinxin

    2011-01-01

    This research is aimed at elucidating surface-energy (or interfacial energy) variation during the process of molecule-layer self-assembly on a solid surface. A quasi-quantitative plotting model is proposed and established to distinguish the surface-energy variation contributed by the three characteristic layers of a thiol-on-gold self-assembled monolayer (SAM), namely the assembly-medium correlative gold/head-group layer, the chain/chain interaction layer and the tail/medium layer, respectively. The data for building the model are experimentally extracted from a set of correlative thiol self-assemblies in different media. The variation in surface-energy during self-assembly is obtained by in situ recording of the self-assembly induced nanomechanical surface-stress using integrated micro-cantilever sensors. Based on the correlative self-assembly experiment, and by using the nanomechanically sensitive self-sensing cantilevers to monitor the self-assembly induced surface-stressin situ, the experimentally extracted separate contributions of the three layers to the overall surface-energy change aid a comprehensive understanding of the self-assembly mechanism. Moreover, the quasi-quantitative modeling method is helpful for optimal design, molecule synthesis and performance evaluation of molecule self-assembly for application-specific surface functionalization.

  17. Study of gamma radiation induced damages and variation of oxygen enhancement ratio with radiation dose using Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Nairy, R.K.; Yerol Narayana; Bhat, N.N.; Anjaria, K.B.; Sreedevi, B.; Sapra, B.K.

    2014-01-01

    In the present study, an attempt has been made to quantify Oxygen Enhancement Ratio (OER) and variation of OER as a function of dose with experimental and theoretical formulations using Saccharomyces cerevisiae D7, X2180 and rad 52. The study confirms that, the variation of OER with dose depends upon type of cell and repair proficiency of cells. A theoretical model has been formulated to estimate OER values. With the help of this model, OER value for any dose can be calculated in the exponential region of the survival curve without actually extending the experiment in that dose region. (author)

  18. Spatial and temporal variations in Pb concentrations and isotopic composition in road dust, farmland soil and vegetation in proximity to roads since cessation of use of leaded petrol in the UK

    International Nuclear Information System (INIS)

    MacKinnon, G.; MacKenzie, A.B.; Cook, G.T.; Pulford, I.D.; Duncan, H.J.; Scott, E.M.

    2011-01-01

    Results are presented for a study of spatial distributions and temporal trends in concentrations of lead (Pb) from different sources in soil and vegetation of an arable farm in central Scotland in the decade since the use of leaded petrol was terminated. Isotopic analyses revealed that in all of the samples analysed, the Pb conformed to a binary mixture of petrol Pb and Pb from industrial or indigenous geological sources and that locally enhanced levels of petrol Pb were restricted to within 10 m of a motorway and 3 m of a minor road. Overall, the dominant source of Pb was historical emissions from nearby industrial areas. There was no discernible change in concentration or isotopic composition of Pb in surface soil or vegetation over the decade since the ban on the sale of leaded petrol. There was an order of magnitude decrease in Pb concentrations in road dust over the study period, but petrol Pb persisted at up to 43% of the total Pb concentration in 2010. Similar concentrations and spatial distributions of petrol Pb and non petrol Pb in vegetation in both 2001 and 2010, with enhanced concentrations near roads, suggested that redistribution of previously deposited material has operated continuously over that period, maintaining a transfer pathway of Pb into the biosphere. The results for vegetation and soil transects near minor roads provided evidence of a non petrol Pb source associated with roads/traffic, but surface soil samples from the vicinity of a motorway failed to show evidence of such a source. - Highlights: → A 10 year study of Pb concentrations and isotopic compositions in farmland. → Soil and vegetation showed no systematic decrease in Pb concentrations over 10 years. → Road dust Pb concentrations fell from 117 mg kg -1 in 2001 to 14.2 mg kg -1 in 2010. → Enhancement of petrol Pb only within 10m of a motorway and 3m of a minor road.

  19. Within- and among-family variation in parasite load and parasite-induced mortality in the land snail Arianta arbustorum, a host of parasitic mites.

    Science.gov (United States)

    Schüpbach, Hans Ulrich; Baur, Bruno

    2010-08-01

    Variation in host susceptibility and parasite-induced mortality are preconditions for parasite-related selection on host populations. In terrestrial gastropods, variation in resistance against ectoparasite infection is poorly understood. We examined the within- and among-family variation in parasite load in full-siblings of the land snail Arianta arbustorum experimentally infected with Riccardoella limacum , a mite living in the mantle cavity of helicid land snails. We also quantified the influence of family origin and host size on parasite load and calculated its heritability (h(2)). Furthermore, we examined the influence of parasite load, snail size, and family origin on host winter mortality, an important life-history trait of A. arbustorum . Parasite load was heritable (h(2) = 0.63). In infected snails, parasite load was affected by family origin and increased with increasing shell size. Host mortality during hibernation increased with increasing parasite load and differed among families, but was not affected by snail size. Our results show high among-family variation both in resistance against ectoparasite infection and in host winter mortality. Furthermore, we show that parasite load is linked to snail size, which suggests that the proliferation of R. limacum is limited by resources provided by A. arbustorum .

  20. Genetic variation of drought tolerance in Pinus pinaster at three hierarchical levels: a comparison of induced osmotic stress and field testing.

    Science.gov (United States)

    Gaspar, Maria João; Velasco, Tania; Feito, Isabel; Alía, Ricardo; Majada, Juan

    2013-01-01

    Understanding the survival capacity of forest trees to periods of severe water stress could improve knowledge of the adaptive potential of different species under future climatic scenarios. In long lived organisms, like forest trees, the combination of induced osmotic stress treatments and field testing can elucidate the role of drought tolerance during the early stages of establishment, the most critical in the life of the species. We performed a Polyethylene glycol-osmotic induced stress experiment and evaluated two common garden experiments (xeric and mesic sites) to test for survival and growth of a wide range clonal collection of Maritime pine. This study demonstrates the importance of additive vs non additive effects for drought tolerance traits in Pinus pinaster, and shows differences in parameters determining the adaptive trajectories of populations and family and clones within populations. The results show that osmotic adjustment plays an important role in population variation, while biomass allocation and hydric content greatly influence survival at population level. Survival in the induced osmotic stress experiment presented significant correlations with survival in the xeric site, and height growth at the mesic site, at population level, indicating constraints of adaptation for those traits, while at the within population level no significant correlation existed. These results demonstrate that population differentiation and within population genetic variation for drought tolerance follow different patterns.

  1. Genetic variation of drought tolerance in Pinus pinaster at three hierarchical levels: a comparison of induced osmotic stress and field testing.

    Directory of Open Access Journals (Sweden)

    Maria João Gaspar

    Full Text Available Understanding the survival capacity of forest trees to periods of severe water stress could improve knowledge of the adaptive potential of different species under future climatic scenarios. In long lived organisms, like forest trees, the combination of induced osmotic stress treatments and field testing can elucidate the role of drought tolerance during the early stages of establishment, the most critical in the life of the species. We performed a Polyethylene glycol-osmotic induced stress experiment and evaluated two common garden experiments (xeric and mesic sites to test for survival and growth of a wide range clonal collection of Maritime pine. This study demonstrates the importance of additive vs non additive effects for drought tolerance traits in Pinus pinaster, and shows differences in parameters determining the adaptive trajectories of populations and family and clones within populations. The results show that osmotic adjustment plays an important role in population variation, while biomass allocation and hydric content greatly influence survival at population level. Survival in the induced osmotic stress experiment presented significant correlations with survival in the xeric site, and height growth at the mesic site, at population level, indicating constraints of adaptation for those traits, while at the within population level no significant correlation existed. These results demonstrate that population differentiation and within population genetic variation for drought tolerance follow different patterns.

  2. Vegetation dynamics and dynamic vegetation science

    NARCIS (Netherlands)

    Van der Maarel, E

    1996-01-01

    his contribution presents a review of the development of the study of vegetation dynamics since 1979, in the framework of a jubilee meeting on progress in the study of vegetation. However, an exhaustive review is both impossible and unnecessary. It is impossible within the few pages available

  3. Solvent micro-evaporation and concentration gradient synergistically induced crystallization of poly(L-lactide) and ring banded supra-structures with radial periodic variation of thickness

    DEFF Research Database (Denmark)

    Huang, Shaoyong; Li, Hongfei; Wen, Huiying

    2014-01-01

    The crystalline morphology and structure of poly(L-lactide) (PLLA) in a PLLA film-chloroform system were investigated by means of wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and atomic force microscopy (AFM). Birefringent and nonbirefringent ring banded supra-structure......The crystalline morphology and structure of poly(L-lactide) (PLLA) in a PLLA film-chloroform system were investigated by means of wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and atomic force microscopy (AFM). Birefringent and nonbirefringent ring banded supra......-structures with radial periodic variation of thickness were obtained, which were induced by micro-evaporation of solvents and concentration gradient of PLLA. The ring banded morphologies consisted of multilayer lamellar crystals, which is a manifestation of alternating ridge and valley bands of periodic variation...

  4. Response of predatory mites to a herbivore-induced plant volatile: genetic variation for context-dependent behaviour.

    Science.gov (United States)

    Sznajder, Beata; Sabelis, Maurice W; Egas, Martijn

    2010-07-01

    Plants infested with herbivores release specific volatile compounds that are known to recruit natural enemies. The response of natural enemies to these volatiles may be either learned or genetically determined. We asked whether there is genetic variation in the response of the predatory mite Phytoseiulus persimilis to methyl salicylate (MeSa). MeSa is a volatile compound consistently produced by plants being attacked by the two-spotted spider mite, the prey of P. persimilis. We predicted that predators express genetically determined responses during long-distance migration where previously learned associations may have less value. Additionally, we asked whether these responses depend on odors from uninfested plants as a background to MeSa. To infer a genetic basis, we analyzed the variation in response to MeSa among iso-female lines of P. persimilis by using choice-tests that involved either (1) MeSa presented as a single compound or (2) MeSa with background-odor from uninfested lima bean plants. These tests were conducted for starved and satiated predators, i.e., two physiological states, one that approximates migration and another that mimics local patch exploration. We found variation among iso-female lines in the responses to MeSa, thus showing genetic variation for this behavior. The variation was more pronounced in the starved predators, thus indicating that P. persimilis relies on innate preferences when migrating. Background volatiles of uninfested plants changed the predators' responses to MeSa in a manner that depended on physiological state and iso-female line. Thus, it is possible to select for context-dependent behavioral responses of natural enemies to plant volatiles.

  5. SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling

    International Nuclear Information System (INIS)

    Edvardsen, Hege; Landmark-Høyvik, Hege; Reinertsen, Kristin V.; Zhao, Xi; Grenaker-Alnæs, Grethe Irene; Nebdal, Daniel; Syvänen, Ann-Christine; Rødningen, Olaug; Alsner, Jan; Overgaard, Jens; Borresen-Dale, Anne-Lise; Fosså, Sophie D.; Kristensen, Vessela N.

    2013-01-01

    Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P≤.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance

  6. Development of a Combined In Vitro Physiologically Based Kinetic (PBK) and Monte Carlo Modelling Approach to Predict Interindividual Human Variation in Phenol-Induced Developmental Toxicity.

    Science.gov (United States)

    Strikwold, Marije; Spenkelink, Bert; Woutersen, Ruud A; Rietjens, Ivonne M C M; Punt, Ans

    2017-06-01

    With our recently developed in vitro physiologically based kinetic (PBK) modelling approach, we could extrapolate in vitro toxicity data to human toxicity values applying PBK-based reverse dosimetry. Ideally information on kinetic differences among human individuals within a population should be considered. In the present study, we demonstrated a modelling approach that integrated in vitro toxicity data, PBK modelling and Monte Carlo simulations to obtain insight in interindividual human kinetic variation and derive chemical specific adjustment factors (CSAFs) for phenol-induced developmental toxicity. The present study revealed that UGT1A6 is the primary enzyme responsible for the glucuronidation of phenol in humans followed by UGT1A9. Monte Carlo simulations were performed taking into account interindividual variation in glucuronidation by these specific UGTs and in the oral absorption coefficient. Linking Monte Carlo simulations with PBK modelling, population variability in the maximum plasma concentration of phenol for the human population could be predicted. This approach provided a CSAF for interindividual variation of 2.0 which covers the 99th percentile of the population, which is lower than the default safety factor of 3.16 for interindividual human kinetic differences. Dividing the dose-response curve data obtained with in vitro PBK-based reverse dosimetry, with the CSAF provided a dose-response curve that reflects the consequences of the interindividual variability in phenol kinetics for the developmental toxicity of phenol. The strength of the presented approach is that it provides insight in the effect of interindividual variation in kinetics for phenol-induced developmental toxicity, based on only in vitro and in silico testing. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. SSR marker analysis on genetic variation of M3 from maize inbred lines 48-2 and R08 after irradiation inducement

    International Nuclear Information System (INIS)

    Li Qi; Shi Haichun; Ke Yongpei; Yuan Jichao; Yu Xuejie

    2011-01-01

    Analyzing the biological effects and the genetic variations of maize mutagenic progenies is important to facilitate effective selections and utilization of the mutants. In this study, the genetic variation of 103 mutagenic progenies of M 3 lines of inbred lines 48-2 and R08 with 60 Co γ-rays inducement were evaluated with SSR molecular markers. The results indicated that, the amplitude of polymorphism information content (PIC) of the 48-2 and R08 M 3 lines ranged 0.307 ∼ 0.948 and 0.108 ∼ 0.955, with an average of 0.762 and 0.701, respectively. The amplitude of genetic diversity indexes (H') ranged 0.552 ∼ 2.830 and 0.254 ∼ 3.309, with an average of 1.830 and 1.777, respectively. The average value of genetic similarity coefficient of the 49 M 3 lines of 48-2 with its check (M673) was 0.8194. However, the average value of genetic similarity coefficient of the M 3 lines of R08 with its check (M487) was 0.8373. Based on the genetic similarity coefficient, inbred lines 48-2, R08 and their 101 M 3 lines were clustered in 7 and 5 populations respectively. This phenomenon indicated that massive genetic variation could appear in progenies due to irradiation. The strengthen of selection and utilization of mutants based on the breeding objectives and in accordance with the feature and regularity on genetic variations of main characteristics of mutant lines in various populations could be enhanced in breeding program, to some extent, which can increase the breeding efficiency of irradiation induced mutation in maize. (authors)

  8. Genetic variation in toll-like receptors and retinoic acid-inducible gene I and outcome of hepatitis C virus infection

    DEFF Research Database (Denmark)

    Clausen, L N; Ladelund, S; Weis, N

    2014-01-01

    We evaluated the effects of genetic variation in toll-like receptors (TLR), retinoic acid-inducible gene I (RIG-I) and their signalling pathways on spontaneous hepatitis C virus (HCV) resolution. We screened 95 single-nucleotide polymorphisms (SNPs) in 22 genes. SNPs significantly associated...... with resolution in the discovery cohort were genotyped in a validation cohort. Multivariate logistic regression adjusted for sex, hepatitis B surface antigen, HIV infection and the interleukin-28B rs12979860 SNP was performed in the combined cohort. Haplotype reconstruction and linkage disequilibrium analysis...

  9. Fruits and vegetables (image)

    Science.gov (United States)

    A healthy diet includes adding vegetables and fruit every day. Vegetables like broccoli, green beans, leafy greens, zucchini, cauliflower, cabbage, carrots, and tomatoes are low in calories and high in fiber, vitamins, and minerals. ...

  10. Vegetable Production System (Veggie)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vegetable Production System (Veggie) was developed to be a simple, easily stowed, high growth volume, low resource facility capable of producing fresh vegetables...

  11. Measurement by γ spectrometry of specific activities of radioisotopes present in vegetal ashes. Study of variations of the ambient radioactivity level in the Grenoble transverse valley from March 1966 to August 1968

    International Nuclear Information System (INIS)

    Chevalier, Michel; Guitton, Pierre; Gagnaire, Janine; Ferard, Guy; Plebin, Roger; LACHET, Bernard

    1969-08-01

    The first part of this report addresses the dosimetry of γ emitting radio-elements which are present in vegetal samples. The dose measurements were performed by spectrometry and results were processed by using a least square method. The second part reports works performed in the Grenoble transverse valley by using the same techniques. Radioactivity fluctuations of various radio-elements ( 40 K, 54 Mn, 95 Zr + 95 Nb, 103 Ru + 106 Rh, 137 Cs, 137 Ba, 140 Ba + 140 La, 144 Ce + 144 Pr) in various vegetal species, in water and in sediments have been monitored in seven points of the Isere river banks, upstream and downstream the city of Grenoble, from March 1966 to August 1968. Fluctuations observed for each radio-element are explained by comparison with physiologic, hydrologic and atmospheric climate conditions. The principles of a systematic control of a site for the detection of possible radioactive pollutions are then defined [fr

  12. In normal human fibroblasts variation in DSB repair capacity cannot be ascribed to radiation-induced changes in the localisation, expression or activity of major NHEJ proteins

    DEFF Research Database (Denmark)

    Kasten-Pisula, Ulla; Vronskaja, Svetlana; Overgaard, Jens

    2008-01-01

    in the activity of the DNA-PK complex induced upon irradiation. CONCLUSIONS: For normal human fibroblasts, the level or activity of NHEJ proteins measured prior to or after irradiation cannot be used to predict the DSB repair capacity or cellular radiosensitivity. Udgivelsesdato: 2008-Mar......BACKGROUND AND PURPOSE: The aim of the present study was to test whether for normal human fibroblasts the variation in double-strand break (DSB) repair capacity results from radiation-induced differences in localisation, expression or activity of major non-homologous end-joining (NHEJ) proteins....... MATERIALS AND METHODS: Experiments were performed with 11 normal human fibroblast strains AF01-11. NHEJ proteins were determined by Western blot and DNA-PK activity by pulldown-assay. RESULTS: The four NHEJ proteins tested (Ku70, Ku80, XRCC4 and DNA-PKcs) were found to be localised almost exclusively...

  13. Determination of strobilurin fungicide residues in fruits and vegetables by nonaqueous micellar electrokinetic capillary chromatography with indirect laser-induced fluorescence.

    Science.gov (United States)

    Guo, Xin; Wang, Kun; Chen, Guan-Hua; Shi, Jie; Wu, Xian; Di, Lu-Lu; Wang, Yi

    2017-08-01

    A nonaqueous micellar electrokinetic capillary chromatography method with indirect LIF was developed for the determination of strobilurin fungicide residues in fruits and vegetables. Hydrophobic CdTe quantum dots (QDs) synthesized in aqueous phase were used as background fluorescent substance. The BGE solution, QD concentration, and separation voltage were optimized to obtain the best separation efficiency and the highest signal intensity. The optimal BGE solution consists of 40 mM phosphate, 120 mM sodium dodecyl sulfate, 15% v/v water and 15% v/v hydrophobic CdTe QDs in formamide, of which apparent pH is 9.5. The optimized separation voltage is controlled as 25 kV. The resultant detection limits of azoxystrobin, kresoxim-methyl, and pyraclostrobin are all 0.001 mg/kg, their linear dynamic ranges are 0.005-2.5 mg/kg, and the recoveries of the spiked samples are 81.7-96.1%, 86.5-95.7%, and 87.3-97.4%, respectively. This method has been proved to be sensitive enough to detect the aforementioned fungicides in fruits and vegetables at the maximum residue limits. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. European Vegetation Archive (EVA)

    NARCIS (Netherlands)

    Chytrý, Milan; Hennekens, S.M.; Jiménez-Alfaro, Borja; Schaminée, J.H.J.; Haveman, Rense; Janssen, J.A.M.

    2016-01-01

    The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and

  15. Modelling the Congo basin ecosystems with a dynamic vegetation model

    Science.gov (United States)

    Dury, Marie; Hambuckers, Alain; Trolliet, Franck; Huynen, Marie-Claude; Haineaux, Damien; Fontaine, Corentin M.; Fayolle, Adeline; François, Louis

    2014-05-01

    The scarcity of field observations in some parts of the world makes difficult a deep understanding of some ecosystems such as humid tropical forests in Central Africa. Therefore, modelling tools are interesting alternatives to study those regions even if the lack of data often prevents sharp calibration and validation of the model projections. Dynamic vegetation models (DVMs) are process-based models that simulate shifts in potential vegetation and its associated biogeochemical and hydrological cycles in response to climate. Initially run at the global scale, DVMs can be run at any spatial scale provided that climate and soil data are available. In the framework of the BIOSERF project ("Sustainability of tropical forest biodiversity and services under climate and human pressure"), we use and adapt the CARAIB dynamic vegetation model (Dury et al., iForest - Biogeosciences and Forestry, 4:82-99, 2011) to study the Congo basin vegetation dynamics. The field campaigns have notably allowed the refinement of the vegetation representation from plant functional types (PFTs) to individual species through the collection of parameters such as the specific leaf area or the leaf C:N ratio of common tropical tree species and the location of their present-day occurrences from literature and available database. Here, we test the model ability to reproduce the present spatial and temporal variations of carbon stocks (e.g. biomass, soil carbon) and fluxes (e.g. gross and net primary productivities (GPP and NPP), net ecosystem production (NEP)) as well as the observed distribution of the studied species over the Congo basin. In the lack of abundant and long-term measurements, we compare model results with time series of remote sensing products (e.g. vegetation leaf area index (LAI), GPP and NPP). Several sensitivity tests are presented: we assess consecutively the impacts of the level at which the vegetation is simulated (PFTs or species), the spatial resolution and the initial land

  16. Sub-micron magnetic patterns and local variations of adhesion force induced in non-ferromagnetic amorphous steel by femtosecond pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huiyan; Feng, Yuping [Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, E08193 (Spain); Nieto, Daniel [Microoptics and GRIN Optics Group, Applied Physics Department, University of Santiago de Compostela, E15782 Santiago de Compostela (Spain); García-Lecina, Eva [Unidad de Superficies Metálicas, IK4-CIDETEC, E20009 Donostia-San Sebastián Gipuzkoa (Spain); Mcdaniel, Clare [National Centre for Laser Applications, School of Physics, National University of Ireland, Galway (Ireland); Díaz-Marcos, Jordi [Unitat de Tècniques Nanomètriques, Centres Científics i Tecnològics, Universitat de Barcelona, E08028 Barcelona (Spain); Flores-Arias, María Teresa [Microoptics and GRIN Optics Group, Applied Physics Department, University of Santiago de Compostela, E15782 Santiago de Compostela (Spain); O’Connor, Gerard M. [National Centre for Laser Applications, School of Physics, National University of Ireland, Galway (Ireland); Baró, Maria Dolors [Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, E08193 (Spain); Pellicer, Eva, E-mail: eva.pellicer@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, E08193 (Spain); and others

    2016-05-15

    Highlights: • Formation of ripples after femtosecond pulsed laser irradiation (FSPLI) of metallic glass was studied. • Magnetic patterning at the surface of non-ferromagnetic amorphous steel was induced by FSPLI. • The origin of the generated ferromagnetism is the laser-induced devitrification. - Abstract: Periodic ripple and nanoripple patterns are formed at the surface of amorphous steel after femtosecond pulsed laser irradiation (FSPLI). Formation of such ripples is accompanied with the emergence of a surface ferromagnetic behavior which is not initially present in the non-irradiated amorphous steel. The occurrence of ferromagnetic properties is associated with the laser-induced devitrification of the glassy structure to form ferromagnetic (α-Fe and Fe{sub 3}C) and ferrimagnetic [(Fe,Mn){sub 3}O{sub 4} and Fe{sub 2}CrO{sub 4}] phases located in the ripples. The generation of magnetic structures by FSPLI turns out to be one of the fastest ways to induce magnetic patterning without the need of any shadow mask. Furthermore, local variations of the adhesion force, wettability and nanomechanical properties are also observed and compared to those of the as-cast amorphous alloy. These effects are of interest for applications (e.g., biological, magnetic recording, etc.) where both ferromagnetism and tribological/adhesion properties act synergistically to optimize material performance.

  17. Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions.

    Science.gov (United States)

    Jansen, Marcel A K; Martret, Bénedicte Le; Koornneef, Maarten

    2010-01-01

    The rise in ultraviolet-B (UV-B) (280-315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful effects of UV-B radiation. However, it is mostly unknown to which extent UV protection is constitutive and/or induced. In this study, we have analysed the role of constitutive and inducible protection responses in avoiding UV-B damage to photosystem II of photosynthesis. We have assayed the UV susceptibility of photosystem II in 224 Arabidopsis thaliana accessions from across the Northern hemisphere, and found a continuum of constitutive UV-protection levels, with some accessions being UV sensitive and others UV tolerant. Statistical analysis showed only very weak associations between constitutive UV tolerance and the geographic origin of accessions. Instead, most of the variance in constitutive UV-B protection of photosynthesis is present at the level of local Arabidopsis populations originating in the same geographic and climatic area. The variance in constitutive UV protection is, however, small compared to the amplitude of environmentally induced changes in UV protection. Thus, our data emphasise the importance of inducible responses for the protection of photosystem II against UV-B. Remarkably, the conditions that induce UV-protective responses vary; accessions from lower latitudes were found to switch-on UV defences more readily than those of higher latitudes. Such altered regulation of induction may comprise a suitable adaptation response when levels of a stressor are fluctuating in the short term, but predictable over longer periods.

  18. Measuring regional and district variations in the incidence of pregnancy-induced hypertension in Ghana: challenges, opportunities and implications for maternal and newborn health policy and programmes.

    Science.gov (United States)

    Antwi, Edward; Klipstein-Grobusch, Kerstin; Quansah Asare, Gloria; Koram, Kwadwo A; Grobbee, Diederick; Agyepong, Irene A

    2016-01-01

    The objectives were to assess the quality of health management information system (HMIS) data needed for assessment of local area variation in pregnancy-induced hypertension (PIH) incidence and to describe district and regional variations in PIH incidence. A retrospective review of antenatal and delivery records of 2682 pregnant women in 10 district hospitals in the Greater Accra and Upper West regions of Ghana was conducted in 2013. Quality of HMIS data was assessed by completeness of reporting. The incidence of PIH was estimated for each district. Key variables for routine assessment of PIH such as blood pressure (BP) at antenatal visits, weight and height were 95-100% complete. Fundal height, gestational age and BP at delivery were not consistently reported. The incidence of PIH differed significantly between Greater Accra region (6.1%) and Upper West region (3.2%). Prevalence of obesity among pregnant women in Greater Accra region (13.9%) was significantly higher than that of women in Upper West region (2.2%). More attention needs to be given to understanding local area variations in PIH and possible relationships with urbanisation and lifestyle changes that promote obesity, to inform maternal and newborn health policy. This can be done with good quality routine HMIS data. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  19. Species specific and environment induced variation of δ13C and δ15N in alpine plants

    Directory of Open Access Journals (Sweden)

    Yang eYang

    2015-06-01

    Full Text Available Stable carbon and nitrogen isotope signals in plant tissues integrate plant-environment interactions over long periods. In this study, we hypothesized that humid alpine life conditions are narrowing the scope for significant deviations from common carbon, water and nitrogen relations as captured by stable isotope signals. We explored the variation in δ13C and δ15N in 32 plant species from tissue type to ecosystem scale across a suite of locations at c. 2500 m elevation in the Swiss Alps. Foliar δ13C and δ15N varied among species by about 3-4 ‰ and 7-8 ‰ respectively. However, there was no overall difference in means of δ13C and δ15N for species sampled in different plant communities or when bulk plant dry matter harvests of different plant communities were compared. δ13C was found to be highly species specific, so that the ranking among species was mostly maintained across 11 habitats. However, δ15N varied significantly from place to place in all species (a range of 2.7 ‰ except in Fabaceae (Trifolium alpinum and Juncaceae (Luzula lutea. There was also a substantial variation among individuals of the same species collected next to each other. No difference was found in foliar δ15N of non-legumes, which were either collected next to or away from the most common legume, T. alpinum. δ15N data place Cyperaceae and Juncaceae, just like Fabaceae, in a low discrimination category, well separated from other families. Soil δ15N was higher than in plants and increased with soil depth. The results indicate a high functional diversity in alpine plants that is similar to that reported for low elevation plants. We conclude that the surprisingly high variation in δ13C and δ15N signals in the studied high elevation plants is largely species specific (genetic and insensitive to obvious environmental cues.

  20. Variations in survival and ''petite'' mutagenesis induced by ultraviolet light during the meiotic cycle of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Hottinguer-de Margerie, Helene; Moustacchi, Ethel

    1975-01-01

    Cyclic variations in sensitivity to killing and cytoplasmic ''petite'' rho induction by ultraviolet light occur during the meiosis of Saccharomyces cerevisiae. Maximal sensitivity to killing coincides with the period of meiotic nuclear DNA synthesis. Cyclic fluctuations in ''petite'' induction could not be correlated with known meiotic events and the pattern could vary temporarily from batch to batch. A dark liquid holding of irradiated cells aided the repair of lethal lesions but on the other hand an enhancement of ''petite'' induction was observed at all meiotic stages [fr

  1. Development of indicators of vegetation recovery based on time series analysis of SPOT Vegetation data

    Science.gov (United States)

    Lhermitte, S.; Tips, M.; Verbesselt, J.; Jonckheere, I.; Van Aardt, J.; Coppin, Pol

    2005-10-01

    Large-scale wild fires have direct impacts on natural ecosystems and play a major role in the vegetation ecology and carbon budget. Accurate methods for describing post-fire development of vegetation are therefore essential for the understanding and monitoring of terrestrial ecosystems. Time series analysis of satellite imagery offers the potential to quantify these parameters with spatial and temporal accuracy. Current research focuses on the potential of time series analysis of SPOT Vegetation S10 data (1999-2001) to quantify the vegetation recovery of large-scale burns detected in the framework of GBA2000. The objective of this study was to provide quantitative estimates of the spatio-temporal variation of vegetation recovery based on remote sensing indicators. Southern Africa was used as a pilot study area, given the availability of ground and satellite data. An automated technique was developed to extract consistent indicators of vegetation recovery from the SPOT-VGT time series. Reference areas were used to quantify the vegetation regrowth by means of Regeneration Indices (RI). Two kinds of recovery indicators (time and value- based) were tested for RI's of NDVI, SR, SAVI, NDWI, and pure band information. The effects of vegetation structure and temporal fire regime features on the recovery indicators were subsequently analyzed. Statistical analyses were conducted to assess whether the recovery indicators were different for different vegetation types and dependent on timing of the burning season. Results highlighted the importance of appropriate reference areas and the importance of correct normalization of the SPOT-VGT data.

  2. Detailed electromagnetic numerical evaluation of eddy currents induced by toroidal and poloidal magnetic field variation and halo currents

    International Nuclear Information System (INIS)

    Roccella, M.; Marin, A.; Lucca, F.; Merola, M.

    2008-01-01

    A detailed evaluation of the EM loads in the ITER divertor during plasma disruptions is mandatory for the correct dimensioning of the divertor component. The EM loads during plasma disruptions are mainly produced by: (1) toroidal flux variation (TFV) during the thermal quench (TQ) and current quench (CQ); (2) halo currents (HC); and (3) poloidal flux variation (PFV) during TQ and CQ phase. The new ITER reference disruption and the last changes in the divertor design have been considered in the EM models created to calculate all the EM loads due to TFV, HC and PFV. All the analyses have been performed for the three different main design options of the divertor plasma facing units (PFU). The effects of PFV have been analyzed using an EM-zooming procedure that has allowed a good detail of the component model, while new numerical approaches have been developed for the evaluation of the effects due to TFV and HC maintaining the same detail for the divertor model. Separate models have been developed to evaluate the equivalent electrical resistivities of the various PFU options; this allows in the full 3D model a strong simplification of a geometry which would otherwise be very complex. The effect of an electrical surface bridging of the PFU castellation has also been taken into account

  3. The use of GRACE data to monitor natural and anthropogenic induced variations in water availability across Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Mohamed; Sultan, Mohamed; Wahr, John; Yan, Eugene

    2014-05-27

    Inter-annual trends in terrestrial water storage (TWS) were extracted from monthly (01/2003–09/2012) Gravity Recovery and Climate Experiment (GRACE) data acquired over Africa and correlated (in a geographic information system [GIS] environment) with relevant temporal remote sensing, geologic, and hydrologic datasets. Findings include the following: (1) large sectors of Africa are undergoing statistically significant TWS variations (+ 44 mm/yr to -15 mm/yr) due to natural and anthropogenic causes; (2) warming of the tropical Atlantic Ocean apparently intensified Atlantic monsoons and increased precipitation and TWS over western and central Africa; (3) warming in the central Indian Ocean decreased precipitation and TWS over eastern Africa; (4) the high frequency of flooding events increased TWS over the Zambezi and Okavango basins; (5) extraction of fossil groundwater decreased TWS over the Saharan aquifers; (6) deforestation decreased TWS in three subbasins (Ubangi, Congo, and Sangha) of the Congo River Basin; and (7) the construction of dams increased TWS in the Blue Nile and Atbara subbasins. Given the 10 years of monthly GRACE data acquired on the subbasin scale across the globe, as well as the plans underway for deployment of a GRACE-FO and GRACE-II, using GRACE-derived TWS data should be considered an alternative, viable index for measuring temporal and spatial variations in water availability.

  4. Detailed electromagnetic numerical evaluation of eddy currents induced by toroidal and poloidal magnetic field variation and halo currents

    Energy Technology Data Exchange (ETDEWEB)

    Roccella, M. [L.T. Calcoli S.a.S. Piazza Prinetti, 26/B, Merate (Lecco) (Italy)], E-mail: massimo.roccella@ltcalcoli.it; Marin, A.; Lucca, F. [L.T. Calcoli S.a.S. Piazza Prinetti, 26/B, Merate (Lecco) (Italy); Merola, M. [ITER Team, Cadarache (France)

    2008-12-15

    A detailed evaluation of the EM loads in the ITER divertor during plasma disruptions is mandatory for the correct dimensioning of the divertor component. The EM loads during plasma disruptions are mainly produced by: (1) toroidal flux variation (TFV) during the thermal quench (TQ) and current quench (CQ); (2) halo currents (HC); and (3) poloidal flux variation (PFV) during TQ and CQ phase. The new ITER reference disruption and the last changes in the divertor design have been considered in the EM models created to calculate all the EM loads due to TFV, HC and PFV. All the analyses have been performed for the three different main design options of the divertor plasma facing units (PFU). The effects of PFV have been analyzed using an EM-zooming procedure that has allowed a good detail of the component model, while new numerical approaches have been developed for the evaluation of the effects due to TFV and HC maintaining the same detail for the divertor model. Separate models have been developed to evaluate the equivalent electrical resistivities of the various PFU options; this allows in the full 3D model a strong simplification of a geometry which would otherwise be very complex. The effect of an electrical surface bridging of the PFU castellation has also been taken into account.

  5. Radiation induced variations in photoperiod-sensitivity, thermo-sensitivity and the number of days to heading in rice

    International Nuclear Information System (INIS)

    Hsieh, S.C.

    1975-01-01

    Radiation induced semi-dwarf mutants derived from five japonica type varieties of rice were studied with regard to their photoperiod-sensitivity, thermo-sensitivity and the number of days to heading. The experiment was carried out under the natural conditions at Taipei. The coefficient of photoperiod-sensitivity and thermo-sensitivity as developed by Oka (1954) were estimated for the mutants in comparison with their original varieties. It was observed that these various physiological characters could be altered easily by mutations. Mutants showed wider ranges in both positive and negative directions than their original varieties in all physiological characters studied. Even though heading date depends on both photoperiod-sensitivity and thermo-sensitivity, it was estimated which of the two contributed more to the induced earliness in each mutant. This offers a basis for selecting early maturing lines of rice

  6. Measurement and Simulation of the Variation in Proton-Induced Energy Deposition in Large Silicon Diode Arrays

    Science.gov (United States)

    Howe, Christina L.; Weller, Robert A.; Reed, Robert A.; Sierawski, Brian D.; Marshall, Paul W.; Marshall, Cheryl J.; Mendenhall, Marcus H.; Schrimpf, Ronald D.

    2007-01-01

    The proton induced charge deposition in a well characterized silicon P-i-N focal plane array is analyzed with Monte Carlo based simulations. These simulations include all physical processes, together with pile up, to accurately describe the experimental data. Simulation results reveal important high energy events not easily detected through experiment due to low statistics. The effects of each physical mechanism on the device response is shown for a single proton energy as well as a full proton space flux.

  7. A minimal model of fire-vegetation feedbacks and disturbance stochasticity generates alternative stable states in grassland–shrubland–woodland systems

    International Nuclear Information System (INIS)

    Batllori, Enric; Ackerly, David D; Moritz, Max A

    2015-01-01

    Altered disturbance regimes in the context of global change are likely to have profound consequences for ecosystems. Interactions between fire and vegetation are of particular interest, as fire is a major driver of vegetation change, and vegetation properties (e.g., amount, flammability) alter fire regimes. Mediterranean-type ecosystems (MTEs) constitute a paradigmatic example of temperate fire-prone vegetation. Although these ecosystems may be heavily impacted by global change, disturbance regime shifts and the implications of fire-vegetation feedbacks in the dynamics of such biomes are still poorly characterized. We developed a minimal modeling framework incorporating key aspects of fire ecology and successional processes to evaluate the relative influence of extrinsic and intrinsic factors on disturbance and vegetation dynamics in systems composed of grassland, shrubland, and woodland mosaics, which characterize many MTEs. In this theoretical investigation, we performed extensive simulations representing different background rates of vegetation succession and disturbance regime (fire frequency and severity) processes that reflect a broad range of MTE environmental conditions. Varying fire-vegetation feedbacks can lead to different critical points in underlying processes of disturbance and sudden shifts in the vegetation state of grassland–shrubland–woodland systems, despite gradual changes in ecosystem drivers as defined by the environment. Vegetation flammability and disturbance stochasticity effectively modify system behavior, determining its heterogeneity and the existence of alternative stable states in MTEs. Small variations in system flammability and fire recurrence induced by climate or vegetation changes may trigger sudden shifts in the state of such ecosystems. The existence of threshold dynamics, alternative stable states, and contrasting system responses to environmental change has broad implications for MTE management. (letter)

  8. Quantification of extracellular levels of corticosterone in the basolateral amygdaloid complex of freely-moving rats: a dialysis study of circadian variation and stress-induced modulation.

    Science.gov (United States)

    Bouchez, Gaëlle; Millan, Mark J; Rivet, Jean-Michel; Billiras, Rodolphe; Boulanger, Raphaël; Gobert, Alain

    2012-05-03

    Corticosterone influences emotion and cognition via actions in a diversity of corticolimbic structures, including the amygdala. Since extracellular levels of corticosterone in brain have rarely been studied, we characterized a specific and sensitive enzymatic immunoassay for microdialysis quantification of corticosterone in the basolateral amygdaloid complex of freely-moving rats. Corticosterone levels showed marked diurnal variation with an evening (dark phase) peak and stable, low levels during the day (light phase). The "anxiogenic agents", FG7142 (20 mg/kg) and yohimbine (10 mg/kg), and an environmental stressor, 15-min forced-swim, induced marked and sustained (1-3 h) increases in dialysis levels of corticosterone in basolateral amygdaloid complex. They likewise increased dialysis levels of dopamine and noradrenaline, but not serotonin and GABA. As compared to basal corticosterone levels of ~200-300 pg/ml, the elevation provoked by forced-swim was ca. 20-fold and this increase was abolished by adrenalectomy. Interestingly, stress-induced rises of corticosterone levels in basolateral amygdaloid complex were abrogated by combined but not separate administration of the corticotrophin releasing factor(1) (CRF(1)) receptor antagonist, CP154,526, and the vasopressin(1b) (V(1b)) receptor antagonist, SSR149,415. Underpinning their specificity, they did not block forced-swim-induced elevations in dopamine and noradrenaline. In conclusion, extracellular levels of corticosterone in the basolateral amygdaloid complex display marked diurnal variation. Further, they are markedly elevated by acute stressors, the effects of which are mediated (in contrast to concomitant elevations in levels of monoamines) by co-joint recruitment of CRF(1) and V(1b) receptors. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Genetic variation in jasmonic acid- and spider mite-induced plant volatile emission of cucumber accessions and attraction of the predator Phytoseiulus persimilis.

    Science.gov (United States)

    Kappers, Iris F; Verstappen, Francel W A; Luckerhoff, Ludo L P; Bouwmeester, Harro J; Dicke, Marcel

    2010-05-01

    Cucumber plants (Cucumis sativus L.) respond to spider-mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites, to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid. We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid using gas chromatography-mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-alpha-farnesene, and (E)-beta-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory mites and other biological control agents.

  10. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J.P.; Sucksdorff, Y. [Finnish Environment Agency, Helsinki (Finland)

    1996-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  11. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J P; Sucksdorff, Y [Finnish Environment Agency, Helsinki (Finland)

    1997-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  12. Flavonoids as fruit and vegetable intake biomarkers

    DEFF Research Database (Denmark)

    Krogholm, Kirstine Suszkiewicz

    of fruit and vegetable intakes. In Paper I, the urinary recovery of the 7 flavonoids in morning spot urine (i.e. all urine voids from midnight including the first morning void) was also found to respond to moderate increases in the intake of fruits and vegetables. However, the association was somewhat...... weaker than in 24h urine samples, indicating that the 24h urinary recovery of the 7 flavonoids is a stronger biomarker of the intake of fruit and vegetables than the urinary recovery of the 7 flavonoids in morning spot urine. In Paper II, the biokinetic profiles of some of the most important dietary......-individual variation in the absorption and urinary recovery of the flavonoids, and this makes it very difficult to separate individuals according to intake by use of the flavonoid biomarker in urine. The intra-individual variation was on the contrary low, and Paper II therefore supports the assumption, that 24h...

  13. Inhibitory Effects of Juices Prepared from Individual Vegetables on CYP3A4 Activity in Recombinant CYP3A4 and LS180 Cells.

    Science.gov (United States)

    Tsujimoto, Masayuki; Agawa, Chie; Ueda, Shinya; Yamane, Takayoshi; Kitayama, Haruna; Terao, Aya; Fukuda, Tomoya; Minegaki, Tetsuya; Nishiguchi, Kohshi

    2017-01-01

    Human intestinal absorption and drug metabolism vary to a large extent among individuals. For example, CYP3A4 activity has large individual variation that cannot be attributed to only genetic differences. Various flavonoids in vegetables, such as kaempferol and quercetin, possess inhibitory effects, and some vegetable and fruit juices have also been found to inhibit CYP3A4 activity. Therefore, differences in daily intake of flavonoid-containing vegetables may induce individual variation in intestinal bioavailability. To identify a vegetable that strongly inhibits CYP3A4, we investigated the effects of juices, prepared from individual vegetables, on CYP3A4 activity using recombinant CYP3A4 and LS180 cells in this study. Nine vegetable juices (cabbage, Japanese radish, onion, tomato, eggplant, carrot, Chinese cabbage, green pepper, and lettuce), were prepared and recombinant CYP3A4 and LS180 cells were used for evaluation of CYP3A4 activity. Metabolism to 6β-hydroxytestosterone by recombinant CYP3A4 was strongly inhibited by cabbage, onion, and green pepper juices, and cabbage and green pepper juices significantly inhibited CYP3A4 activity in a preincubation time-dependent manner. In addition, CYP3A4 activity in LS180 cells was significantly inhibited by cabbage and onion juices. In conclusion, this study showed that juices prepared from some individual vegetables could significantly inhibit CYP3A4 activity. Therefore, variation in the daily intake of vegetables such as cabbage and onion may be one of the factors responsible for individual differences in intestinal bioavailability.

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

    Science.gov (United States)

    Ardö, Jonas

    2015-12-01

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

  15. Allelic variation of the inducible costimulator (ICOS) gene: detection of polymorphisms, analysis of the promoter region, and extended haplotype estimation

    DEFF Research Database (Denmark)

    Andersen, A.D.H.; Lange, Marianne; Lillevang, S.T.

    2003-01-01

    The human chromosome region 2q33 including the three costimulatory molecules CD28, CTLA-4 and ICOS, has been subject to much attention due to its linkage to a number of autoimmune diseases. The search for the causal relationship of this linkage has revealed several polymorphisms, but no variations...... in the amino acid sequences except for one polymorphism in, the leader sequence of CTLA-4. In the present study, we examined the ICOS gene of an unrelated group of healthy donors from the Danish population. We were able to report 16 intronic SNP, one intronic G-insert and two repeat regions in intron 4......, consistent with the [T](n) and the [GT](n) regions reported in a Japanese study. Putative haplotypes for the established SNP and repeat polymorphisms have been estimated by computational analysis. Sequencing of similar to3500 by of the upstream region of ICOS revealed an additional eight SNP of which two...

  16. Variations on seepage water geochemistry induced by natural and anthropogenic microclimatic changes: Implications for the speleothems growth conditions

    Science.gov (United States)

    Fernandez-Cortes, A.; Sanchez-Moral, S.; Canaveras, J. C.; Cuevas, J.; Cuezva, S.; Andreu, J. M.; Abella, R.

    2009-04-01

    During an annual cycle the effect of microclimatic changes (natural and anthropogenic origin) on the geochemical characteristics of seepage water and mineral precipitation rates was analyzed, for two karstic caves under opposing environmental stability and energy exchange with exterior. On the one hand Castañar cave (Caceres, Spain), an extremely controlled show cave with limited visitation showing a minimum exchange rate of energy with the outer atmosphere and, secondly, Canelobre cave (Alicante, Spain), a widely visited cave where the anthropogenic impact generates both high-speed and high-energy environmental changes. Microclimatic variations play a key role in CO2-dessgasing caused by the imbalance of pCO2 between the karstic water and the cave air, favoring the slow processes of mineral precipitation. Thus, a pCO2-range of seepage water have been detected for each cave (from 10-2.30/-2.35 to 10-2.47/-2.52 bar for Castañar cave, and from 10-2.8/-2.85 to 10-2.95/-3.0 bar for Canelobre cave) where the mineral oversaturation prevails, determining the type and rate of mineral precipitation in each cave. Finally, it analyzes how the changes on the oversaturation/ precipitation states are controlled by microclimatic variations, such as: 1) natural underground air renewal through the porous system of upper soil and the network of host-rock fissures (isolating membranes), or else through the cave entrance, 2) cumulative disruptions in the pCO2 levels of cave air due to the presence of visitors, and 3) forced ventilation of the subterranean atmosphere due to the uncontrolled opening of cave entrances. The obtained results reinforce the significance of the microclimatic fluctuations on short time scales in the dynamic and evolution of the subterranean karst system, in terms of rates of mineral precipitation and growth of speleothems. Likewise the interpretations are useful in order to ensure the constant climate required for the conservation of caves.

  17. Diurnal variations of summertime precipitation over the Tibetan Plateau in relation to orographically-induced regional circulations

    International Nuclear Information System (INIS)

    Liu Xiaodong; Bai Aijuan; Liu Changhai

    2009-01-01

    The diurnal patterns of variation of summertime precipitation over the Tibetan Plateau were first investigated using the TRMM multi-satellite precipitation analysis product for five summer seasons (i.e. June to August for 2002-2006). Both hourly precipitation amount and precipitation frequency exhibit pronounced daily variability with an overall late-afternoon-evening maximum and a dominant morning minimum. A notable exception is the prevalent nocturnal maximum around the periphery of the Plateau. In terms of the normalized harmonic amplitude, the diurnal signal shows significant regional contrast with the strongest manifestation over the central Plateau and the weakest near the periphery. This remarkable spatial dependence in daily rainfall cycles is clear evidence of orographic and heterogeneous land-surface impacts on convective development. Using six-hourly NCEP FNL data, we then examined the diurnal variability in the atmospheric circulation and thermodynamics in this region. The results show that the Plateau heats (cools) the overlying atmosphere during the day (night) more than the surrounding areas, and as a consequence a relatively stronger confluent circulation in this region occurs during the day than during the night, consistent with the diurnal rainfall cycles. Moreover, the regions with large low-level convergence and upper-level divergence correspond to the strong diurnal rainfall variations. The reversed daily alterations of convergence-divergence patterns in the vicinity of the Plateau edges are in agreement with the observed nighttime rainfall peak therein. This study further demonstrates the importance of the Tibetan Plateau in regulating regional circulation and precipitation.

  18. Boreal and temperate snow cover variations induced by black carbon emissions in the middle of the 21st century

    Directory of Open Access Journals (Sweden)

    M. Ménégoz

    2013-03-01

    Full Text Available We used a coupled climate-chemistry model to quantify the impacts of aerosols on snow cover north of 30° N both for the present-day and for the middle of the 21st century. Black carbon (BC deposition over continents induces a reduction in the mean number of days with snow at the surface (MNDWS that ranges from 0 to 10 days over large areas of Eurasia and Northern America for the present-day relative to the pre-industrial period. This is mainly due to BC deposition during the spring, a period of the year when the remaining of snow accumulated during the winter is exposed to both strong solar radiation and a large amount of aerosol deposition induced themselves by a high level of transport of particles from polluted areas. North of 30° N, this deposition flux represents 222 Gg BC month−1 on average from April to June in our simulation. A large reduction in BC emissions is expected in the future in all of the Representative Concentration Pathway (RCP scenarios. In particular, considering the RCP8.5 in our simulation leads to a decrease in the spring BC deposition down to 110 Gg month−1 in the 2050s. However, despite the reduction of the aerosol impact on snow, the MNDWS is strongly reduced by 2050, with a decrease ranging from 10 to 100 days from present-day values over large parts of the Northern Hemisphere. This reduction is essentially due to temperature increase, which is quite strong in the RCP8.5 scenario in the absence of climate mitigation policies. Moreover, the projected sea-ice retreat in the next decades will open new routes for shipping in the Arctic. However, a large increase in shipping emissions in the Arctic by the mid-21st century does not lead to significant changes of BC deposition over snow-covered areas in our simulation. Therefore, the MNDWS is clearly not affected through snow darkening effects associated with these Arctic ship emissions. In an experiment without nudging toward atmospheric reanalyses, we simulated

  19. Variation in the HFE gene is associated with the development of bleomycin-induced pulmonary toxicity in testicular cancer patients.

    Science.gov (United States)

    van der Schoot, Gabriela G F; Westerink, Nico-Derk L; Lubberts, Sjoukje; Nuver, Janine; Zwart, Nynke; Walenkamp, Annemiek M E; Wempe, Johan B; Meijer, Coby; Gietema, Jourik A

    2016-05-01

    Bleomycin and cisplatin are of key importance in testicular cancer treatment. Known potential serious adverse effects are bleomycin-induced pulmonary toxicity (BIP) and cisplatin-induced renal toxicity. Iron handling may play a role in development of this toxicity. Carriage of allelic variants of the HFE gene induces altered iron metabolism and may contribute to toxicity. We investigated the association between two common allelic variants of the HFE gene, H63D and C282Y, with development of pulmonary and renal toxicity during and after treatment with bleomycin- and cisplatin-containing chemotherapy. In 369 testicular cancer patients treated with bleomycin and cisplatin at the University Medical Center Groningen between 1978 and 2006, H63D and/or C282Y genotypes were determined with an allelic discrimination assay. Data were collected on development of BIP, pulmonary function parameters, renal function, and survival. BIP developed more frequently in patients who were heterozygote (16 in 75, 21%) and homozygote (2 in 4, 50%) for the H63D variant, compared with those who had the HFE wild-type gene (31 in 278, 11%) (p = 0.012). Overall survival, testicular cancer-related survival, and change in renal function were not associated with the H63D variant. We observed an association between presence of one or both H63D alleles and development of BIP in testicular cancer patients treated with bleomycin combination chemotherapy. In patients heterozygote and homozygote for the H63D variant, BIP occurred more frequently compared with wild-type patients. When validated and confirmed, HFE H63D genotyping may be used to identify patients with increased risk for pulmonary bleomycin toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Utilization of Cassava Leaves as a Vegetable in Rwanda ...

    African Journals Online (AJOL)

    . The objectives of this study were to determine cassava species from which leaves are harvested as vegetable and identify leaf preparation methods, consumption rate, price variation, storability and perception of post-harvest losses.

  1. Genetical analysis of the induced variation by gamma radiation in quantitative characters of Caupi [Vigna unguiculata (L.) Walp.

    International Nuclear Information System (INIS)

    Araujo, J.P.P. de.

    1987-10-01

    Genetical analysis procedures of the cobalt 60 gamma radiation effects in the induced mutations in quantitative characters of Caupi BR-1 Poty. The following characters were evaluated: day to first flower (FI), number of pods per plant (NVP), pod lenght (CMV), number of suds per pod (NSV), 100 seed wright (PCS), seed yield per plant (PSP) and seed yield per plant estimated by yield components (PSPE). The resistance of irradiated populations to cowpea aphid-borne mosaic virus (CpAMV)was also evaluated. (L.M.J.) [pt

  2. Magnetic field-induced cluster formation and variation of magneto-optical signals in zinc-substituted ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Nair, S.S. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022 (India)]. E-mail: swapna@cusat.ac.in; Rajesh, S. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022 (India); Abraham, V.S. [School of Engineering and Sciences, International University of Bremen, 28759 (Germany); Anantharaman, M.R. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022 (India)]. E-mail: mraiyer@yahoo.com; Nampoori, V.P.N. [International School of Photonics, Cochin University of Science and Technology, Cochin-22 (India)

    2006-10-15

    Fine magnetic particles (size{approx_equal}100 A) belonging to the series Zn {sub x} Fe{sub 1-} {sub x} Fe{sub 2}O{sub 4} were synthesized by cold co-precipitation methods and their structural properties were evaluated using X-ray diffraction. Magnetization studies have been carried out using vibrating sample magnetometry (VSM) showing near-zero loss loop characteristics. Ferrofluids were then prepared employing these fine magnetic powders using oleic acid as surfactant and kerosene as carrier liquid by modifying the usually reported synthesis technique in order to induce anisotropy and enhance the magneto-optical signals. Liquid thin films of these fluids were prepared and field-induced laser transmission through these films was studied. The transmitted light intensity decreases at the centre with applied magnetic field in a linear fashion when subjected to low magnetic fields and saturate at higher fields. This is in accordance with the saturation in cluster formation. The pattern exhibited by these films in the presence of different magnetic fields was observed with the help of a CCD camera and was recorded photographically.

  3. Induced micro-mutations in rice - the frequency and spectrum of gamma ray induced height variations in rice variety-Jaya

    International Nuclear Information System (INIS)

    Nair, N.K.; Ninan, C.A.

    1975-01-01

    Seeds of rice variety, Jaya, treated with moderate doses of (10, 20 and 30 kR) gamma rays were subjected to study the relative magnitude of induced variability and the type of mutations induced for height of plant in M 2 and M 3 generations. Progenies of 3352 M 1 spikes, totalling to 35691 M 2 plants and their subsequent progenies in M 3 were analysed. To get wider variability, very large populations in all the generations were studied. The mean value, genetic variance and phenotypic frequency distribution with and between generations were studied. The treated population showed no significant shift in mean values from that of control. The variance was greater in the irradiated material compared to control. The variability was found to shift in both plus and minus direction from that of control with a higher frequency in the minus direction in M 2 . A high frequency of dwarf mutants was observed in 20 kR treated population in the M 2 generation. The segregation ratio was higher in M 2 compared to M 3 generation. (author)

  4. Isolation and propagation of mutations by in vitro culture. Part of a coordinated programme on improvement of vegetatively propagated crops and tree crops through radiation induced mutations

    International Nuclear Information System (INIS)

    Asahira, T.

    1974-01-01

    Tuberous roots of two Dahlia cultivars were irradiated with 1000 - 2000 R of x-rays. Chlorophyll and flower colour mutations were scored on M 1 plants and the subsequent vegetatively propagated generations. The project aimed at the development of experimental methods suitable for easy isolation of mutated tissue chimeras deriving from mutagen treatment. In comparing in vivo methods such as leaf bud cutting and root propagation with in vitro methods using explants from leaves and florets, the problems encountered by in vitro culture were so manifold, that this method is not considered to be at present of much promise. These experimental results should not discourage from developing and using in vitro culture methods for mutant isolation in other plant species, particularly those were in vivo adventitious bud techniques are not available. Besides the main result obtained, the following valuable observations were made: a) The genotype used for mutation induction is not only relevant for the number and the spectrum of mutations, but also size of chimerical sectors. b) Flower colour changes, which were investigated in some detail, revealed that pigments were lost as groups e.g. all buteins in one case and all cyanins plus pelargonins in another case. c) When using the leaf bud cutting method the greatest frequency of mutations was recovered from the axillary bud of the leaf, that is at the youngest primordial stage at the time of mutagen treatment

  5. Monitoring climate and man-made induced variations in terrestrial water storage (TWS) across Africa using GRACE data

    Science.gov (United States)

    Ahmed, M. E.; Sultan, M.; Wahr, J. M.; Yan, E.; Bonin, J. A.; Chouinard, K.

    2012-12-01

    It is common practice for researchers engaged in research related to climate change to examine the temporal variations in relevant climatic parameters (e.g., temperature, precipitation) and to extract and examine drought indices reproduced from one or more such parameters. Drought indices (meteorological, agricultural and hydrological) define departures from normal conditions and are used as proxies for monitoring water availability. Many of these indices exclude significant controlling factor(s), do not work well in specific settings and regions, and often require long (≥50 yr) calibration time periods and substantial meteorological data, limiting their application in areas lacking adequate observational networks. Additional uncertainties are introduced by the models used in computing model-dependent indices. Aside from these uncertainties, none of these indices measure the variability in terrestrial water storage (TWS), a term that refers to the total vertically integrated water content in an area regardless of the reservoir in which it resides. Inter-annual trends in TWS were extracted from monthly Gravity Recovery and Climate Experiment (GRACE) data acquired (04/2002 to 08/2011) over Africa and correlated (in a GIS environment) with relevant temporal remote sensing, geologic, hydrologic, climatic, and topographic datasets. Findings include the following: (1) large sectors of Africa are undergoing statistically significant variations (+36 mm/yr to -16 mm/yr) due to natural and man-made causes; (2) warming of the tropical Atlantic ocean apparently intensified Atlantic monsoons and increased precipitation and TWS over western and central Africa's coastal plains, proximal mountainous source areas, and inland areas as far as central Chad; (3) warming in the central Indian Ocean decreased precipitation and TWS over eastern and southern Africa; (4) the high frequency of negative phases of the North Atlantic Oscillation (NAO) increased precipitation and TWS over

  6. Variation in apoptosis mechanisms employed by malaria parasites: the roles of inducers, dose dependence and parasite stages

    Directory of Open Access Journals (Sweden)

    Matthews Holly

    2012-08-01

    Full Text Available Abstract Background Plasmodium berghei ookinetes exhibit an apoptotic phenotype when developing within the mosquito midgut lumen or when cultured in vitro. Markers of apoptosis increase when they are exposed to nitric oxide or reactive oxygen species but high concentrations of hydrogen peroxide cause death without observable signs of apoptosis. Chloroquine and other drugs have been used to induce apoptosis in erythrocytic stages of Plasmodium falciparum and to formulate a putative pathway involving cysteine protease activation and mitochondrial membrane permeabilization; initiated, at least in the case of chloroquine, after its accumulation in the digestive vacuole causes leakage of the vacuole contents. The lack of a digestive vacuole in ookinetes prompted the investigation of the effect of chloroquine and staurosporine on this stage of the life cycle. Finally, the suggestion that apoptosis may have evolved as a strategy employed by ookinetes to increase the fitness of surviving parasites was explored by determining whether increasing the ecological triggers parasite density and nutrient depletion induced apoptosis. Methods Ookinetes were grown in culture then either exposed to hydrogen peroxide, chloroquine or staurosporine, or incubated at different densities and in different media. The proportion of ookinetes displaying positive markers for apoptosis in treated samples was compared with controls and results were analyzed using analysis of variance followed by a Turkey’s test, or a Kruskal-Wallis test as appropriate. Results Hydrogen peroxide below 50 μM triggered apoptosis but cell membranes were rapidly compromised by higher concentrations, and the mode of death could not be defined. Both chloroquine and staurosporine cause a significant increase in ookinetes with condensed chromatin, caspase-like activity and, in the case of chloroquine, phosphatidylserine translocation and DNA fragmentation (not investigated for staurosporine. However

  7. Spectral lines and characteristic of temporal variations in photoionized plasmas induced with laser-produced plasma extreme ultraviolet source

    Science.gov (United States)

    Saber, I.; Bartnik, A.; Wachulak, P.; Skrzeczanowski, W.; Jarocki, R.; Fiedorowicz, H.

    2017-11-01

    Spectral lines for Kr/Ne/H2 photoionized plasma in the ultraviolet and visible (UV/Vis) wavelength ranges have been created using a laser-produced plasma (LPP) EUV source. The source is based on a double-stream gas puff target irradiated with a commercial Nd:YAG laser. The laser pulses were focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Spectral lines from photoionization in neutral Kr/Ne/H2 and up to few charged states were observed. The intense emission lines were associated with the Kr transition lines. Experimental and theoretical investigations on intensity variations for some ionic lines are presented. A decrease in the intensity with the delay time between the laser pulse and the spectrum acquisition was revealed. Electron temperature and electron density in the photoionized plasma have been estimated from the characteristic emission lines. Temperature was obtained using Boltzmann plot method, assuming that the population density of atoms and ions are considered in a local thermodynamic equilibrium (LTE). Electron density was calculated from the Stark broadening profile. The temporal evaluation of the plasma and the way of optimizing the radiation intensity of LPP EUV sources is discussed.

  8. Variation of Qingke (Hordeum vulgare linn.var.nudum Hook.f) induced by space flight treatment

    International Nuclear Information System (INIS)

    Li Xin; Peng Zhengsong; Yang Jun

    2007-01-01

    108 Dry seeds of Qingke (Hordeum vulgate linn. var. nudum Hook. f) were carried into space by recoverable satellite. after wards, the seeds were germinated into 108 seedlings at room temperature, and root tips were observed with Night microscope, and results and normal mitotic division was found without microkemel at interphase or chromosome bridges at anaphase, which means that chromosomal structure change didn't occur in Qingke seeds during space flight. To investigate whether there were morphology variations taken place, the seedlings were transplanted into field and managed normal. All of plants grew as strong as normal Qingke plants (CK) by eye abservation, except two plants showed abnormal inflorescence morphology, which had two spikes on one tiller. 21 SSR markers on 7 linkage groups were used to analysis the polymorphism of genomic DNA for these Qingke plants. No polymorphism was detected with 20 SSR markers among 63 plants investigated. But varied electrophoretic bands were tested in 10 plants using the marker HVM54 on chromosome 2H, and all the 10 plants showed uniform electrophoretypes. It was concluded that the DNA of the Qingke could be changed during space flight. (authors)

  9. Irradiation of dehydrated vegetables

    International Nuclear Information System (INIS)

    Esterhuyse, A; Esterhuizen, T.

    1985-01-01

    The reason for radurization was to decreased the microbial count of dehydrated vegetables. The average absorbed irradiation dose range between 2kGy and 15kGy. The product catagories include a) Green vegetables b) White vegetables c) Powders of a) and b). The microbiological aspects were: Declining curves for the different products of T.P.C., Coliforms, E. Coli, Stap. areus, Yeast + Mold at different doses. The organoleptical aspects were: change in taste, flavour, texture, colour and moisture. The aim is the marketing of irradiated dehydrated vegetables national and international basis

  10. Quantifying redox-induced Schottky barrier variations in memristive devices via in operando spectromicroscopy with graphene electrodes

    Science.gov (United States)

    Baeumer, Christoph; Schmitz, Christoph; Marchewka, Astrid; Mueller, David N.; Valenta, Richard; Hackl, Johanna; Raab, Nicolas; Rogers, Steven P.; Khan, M. Imtiaz; Nemsak, Slavomir; Shim, Moonsub; Menzel, Stephan; Schneider, Claus Michael; Waser, Rainer; Dittmann, Regina

    2016-08-01

    The continuing revolutionary success of mobile computing and smart devices calls for the development of novel, cost- and energy-efficient memories. Resistive switching is attractive because of, inter alia, increased switching speed and device density. On electrical stimulus, complex nanoscale redox processes are suspected to induce a resistance change in memristive devices. Quantitative information about these processes, which has been experimentally inaccessible so far, is essential for further advances. Here we use in operando spectromicroscopy to verify that redox reactions drive the resistance change. A remarkable agreement between experimental quantification of the redox state and device simulation reveals that changes in donor concentration by a factor of 2-3 at electrode-oxide interfaces cause a modulation of the effective Schottky barrier and lead to >2 orders of magnitude change in device resistance. These findings allow realistic device simulations, opening a route to less empirical and more predictive design of future memory cells.

  11. Dynamics of Membrane Potential Variation and Gene Expression Induced by Spodoptera littoralis, Myzus persicae, and Pseudomonas syringae in Arabidopsis

    Science.gov (United States)

    Bricchi, Irene; Bertea, Cinzia M.; Occhipinti, Andrea; Paponov, Ivan A.; Maffei, Massimo E.

    2012-01-01

    Background Biotic stress induced by various herbivores and pathogens invokes plant responses involving different defense mechanisms. However, we do not know whether different biotic stresses share a common response or which signaling pathways are involved in responses to different biotic stresses. We investigated the common and specific responses of Arabidopsis thaliana to three biotic stress agents: Spodoptera littoralis, Myzus persicae, and the pathogen Pseudomonas syringae. Methodology/Principal Findings We used electrophysiology to determine the plasma membrane potential (Vm) and we performed a gene microarray transcriptome analysis on Arabidopsis upon either herbivory or bacterial infection. Vm depolarization was induced by insect attack; however, the response was much more rapid to S. littoralis (30 min −2 h) than to M. persicae (4–6 h). M. persicae differentially regulated almost 10-fold more genes than by S. littoralis with an opposite regulation. M. persicae modulated genes involved in flavonoid, fatty acid, hormone, drug transport and chitin metabolism. S. littoralis regulated responses to heat, transcription and ion transport. The latest Vm depolarization (16 h) was found for P. syringae. The pathogen regulated responses to salicylate, jasmonate and to microorganisms. Despite this late response, the number of genes differentially regulated by P. syringae was closer to those regulated by S. littoralis than by M. persicae. Conclusions/Significance Arabidopsis plasma membranes respond with a Vm depolarization at times depending on the nature of biotic attack which allow setting a time point for comparative genome-wide analysis. A clear relationship between Vm depolarization and gene expression was found. At Vm depolarization timing, M. persicae regulates a wider array of Arabidopsis genes with a clear and distinct regulation than S. littoralis. An almost completely opposite regulation was observed between the aphid and the pathogen, with the former

  12. Responses of sun-induced chlorophyll fluorescence to biological and environmental variations measured with a versatile Fluorescence Auto-Measurement Equipment (FAME)

    Science.gov (United States)

    Gu, L.

    2017-12-01

    In this study, we examine responses of sun-induced chlorophyll fluorescence to biological and environmental variations measured with a versatile Fluorescence Auto-Measurement Equipment (FAME). FAME was developed to automatically and continuously measure chlorophyll fluorescence (F) of a leaf, plant or canopy in both laboratory and field environments, excited by either artificial light source or sunlight. FAME is controlled by a datalogger and allows simultaneous measurements of environmental variables complementary to the F signals. A built-in communication system allows FAME to be remotely monitored and data-downloaded. Radiance and irradiance calibrations can be done online. FAME has been applied in a variety of environments, allowing an investigation of biological and environmental controls on F emission.

  13. Variation of normal tissue complication probability (NTCP) estimates of radiation-induced hypothyroidism in relation to changes in delineation of the thyroid gland

    DEFF Research Database (Denmark)

    Rønjom, Marianne Feen; Brink, Carsten; Laugaard Lorenzen, Ebbe

    2015-01-01

    volume, Dmean and estimated risk of HT. Bland-Altman plots were used for assessment of the systematic (mean) and random [standard deviation (SD)] variability of the three parameters, and a method for displaying the spatial variation in delineation differences was developed. Results. Intra......-observer variability resulted in a mean difference in thyroid volume and Dmean of 0.4 cm(3) (SD ± 1.6) and -0.5 Gy (SD ± 1.0), respectively, and 0.3 cm(3) (SD ± 1.8) and 0.0 Gy (SD ± 1.3) for inter-observer variability. The corresponding mean differences of NTCP values for radiation-induced HT due to intra- and inter...

  14. Radiation-induced sprout and growth inhibition in vegetables with special reference to the susceptibility to microbial attacks and the effect of calcium

    International Nuclear Information System (INIS)

    Skou, J.P.

    1979-03-01

    Experiments have shown ionizing irradiation to be an effective method for sprout and growth inhibition but it is necessary to keep the doses at the absolute minimum in order to avoid unwanted by-effects One of the by-effects is an increased susceptibility to storage rot in potatoes, onions and carrots. This effect is connected with the wounding and bruising caused by digging up and handling as the wound healing process is inhibited simultaneously with the sprout inhibition. Patogens increase tissue permeability during pathogenesis and, as irradiation has an analogous effect on tissues it might facilitate the growth of the pathogens. Irradiation softens the tissue and mobilizes the calcium in the tissue; this may thereby make the tissue more accessible to microbial attack. An external supply of calcium increases the firmness of tissue, reduces tissue permeability, and may compensate for the loss of calcium in irradiated tissue mainly as a result of a surplus of calcium in the wounds. Botrytis cinerea and Sclerotinia sclerotiorum were some of the most wide spread and serious pathogens in carrots, which vegetable were the main object of the studies. Culture filtrates of these fungi had a strong macerating activity on carrot tissues. The effect, which results from activity and interaction of pectolytic enzymes and oxalic acid, could be reduced or nullified by calcium. A diversity of the groups of pectolytic enzymes are widely distributed among organisms and not confined to plant pathogens. Because of this, because there exists pectolytic enzymes for every condition and pectic substances, and because calcium is not very inhibiting to all kinds of pectolytic enzymes it is not to be expected that the protective effect of calcium will always be expressed to the same extent on storage of the products. (author)

  15. Multi-technique approach for deriving a VLBI signal extra-path variation model induced by gravity: the example of Medicina

    Science.gov (United States)

    Sarti, P.; Abbondanza, C.; Negusini, M.; Vittuari, L.

    2009-09-01

    During the measurement sessions gravity might induce significant deformations in large VLBI telescopes. If neglected or mismodelled, these deformations might bias the phase of the incoming signal thus corrupting the estimate of some crucial geodetic parameters (e.g. the height component of VLBI Reference Point). This paper describes a multi-technique approach implemented for measuring and quantifying the gravity-dependent deformations experienced by the 32-m diameter VLBI antenna of Medicina (Northern Italy). Such an approach integrates three different methods: Terrestrial Triangulations and Trilaterations (TTT), Laser Scanning (LS) and a Finite Element Model (FEM) of the antenna. The combination of the observations performed with these methods allows to accurately define an elevation-dependent model of the signal path variation which appears to be, for the Medicina telescope, non negligible. In the range [0,90] deg the signal path increases monotonically by almost 2 cm. The effect of such a variation has not been introduced in actual VLBI analysis yet; nevertheless this is the task we are going to pursue in the very next future.

  16. Observed changes of temperature extremes during 1960-2005 in China: natural or human-induced variations?

    Science.gov (United States)

    Zhang, Qiang; Li, Jianfeng; David Chen, Yongqin; Chen, Xiaohong

    2011-12-01

    The purpose of this study was to statistically examine changes of surface air temperature in time and space and to analyze two factors potentially influencing air temperature changes in China, i.e., urbanization and net solar radiation. Trends within the temperature series were detected by using Mann-Kendall trend test technique. The scientific problem this study expected to address was that what could be the role of human activities in the changes of temperature extremes. Other influencing factors such as net solar radiation were also discussed. The results of this study indicated that: (1) increasing temperature was observed mainly in the northeast and northwest China; (2) different behaviors were identified in the changes of maximum and minimum temperature respectively. Maximum temperature seemed to be more influenced by urbanization, which could be due to increasing urban albedo, aerosol, and air pollutions in the urbanized areas. Minimum temperature was subject to influences of variations of net solar radiation; (3) not significant increasing and even decreasing temperature extremes in the Yangtze River basin and the regions south to the Yangtze River basin could be the consequences of higher relative humidity as a result of increasing precipitation; (4) the entire China was dominated by increasing minimum temperature. Thus, we can say that the warming process of China was reflected mainly by increasing minimum temperature. In addition, consistently increasing temperature was found in the upper reaches of the Yellow River basin, the Yangtze River basin, which have the potential to enhance the melting of permafrost in these areas. This may trigger new ecological problems and raise new challenges for the river basin scale water resource management.

  17. Variations in leptin, nesfatin-1 and irisin levels induced by aerobic exercise in young trained and untrained male subjects

    Directory of Open Access Journals (Sweden)

    Sermin Algul

    2017-12-01

    Full Text Available The aims of this study were to investigate the impacts of acute aerobic exercise on circulating levels of hormones associated with energy metabolism, namely leptin, nesfatin-1 and irisin, in trained and untrained male subjects and to determine whether the timing of the exercise (i.e. morning or night amplified these impacts. Thirty trained (19.2±0.7 years and 30 untrained (19.5±0.6 years male subjects performed two aerobic running exercises (3 days between tests to 64-76% of the subjects’ maximal heart rate for about 30 min. Pre- and post-exercise venous blood samples were taken and analysed for leptin, nesfatin-1 and irisin using enzyme-linked immunosorbent assay (ELISA. Paired samples and independent samples t-tests were used to analyse data. Irisin levels increased in all the subjects (p<0.001. In both groups, nesfatin-1 levels increased significantly after the night-time exercise (p<0.05. Importantly, leptin and nesfatin-1 levels varied among the trained and untrained groups: Both leptin and nesfatin-1 levels increased in 4 (13% and 12 (40% subjects, respectively, after the morning exercises, and they increased in 9 (30% and 10 (33% subjects, respectively, after the night-time exercise. They decreased in 5 (16% and 7 (23% subjects, respectively, after the morning exercise and in 6 (20% and 3 (10% subjects, respectively, after the night-time exercise. Exercise may result in increased energy consumption by altering irisin levels. However, due to variations among individuals, increasing leptin and nesfatin-1 levels by reducing food intake may not be applicable.

  18. Variation of Bragg curve characteristic induced by changing the position of inhomogeneous material: Geant4 simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Park, So-Hyun; Jung, Won-Gyun; Suh, Tae-Suk [Catholic University, Seoul (Korea, Republic of); Jang, Hong-Seok; Choi, Byeong-Oak [Seoul St. Mary' s Hospital, Seoul (Korea, Republic of); Rah, Jeong-Eun; Park, Sun-Gyong; Lee, Se-Byeong [National Cancer Center, Ilsan (Korea, Republic of)

    2011-02-15

    When proton beam passes through the human body, the stopping power and the depth-dose distribution of the proton are influenced by the relative location among adjacent materials or the difference in material conditions. Our study demonstrates the effect of inhomogeneous materials placed in the Plateau and Bragg peak regions of the Bragg curve in water. We evaluated the Bragg peak position, range, penumbra and integrated doses by using the Geant4 simulation toolkit. The positions of inhomogeneities were selected as the proximal 36% and 50% points of the maximum dose, which indicates the location at entrance regions of the Plateau and the Bragg peak, respectively. Bone (density {rho} = 1.85 g/cm{sup 3}) and adipose tissue (density {rho} = 0.92 g/cm{sup 3}) were selected as inhomogeneous materials. The thickness of each material was varied by 0.1 cm between 0.1 cm and 1.0 cm. In addition, the initial energy of the proton beam was changed in 30 MeV steps between 108 MeV and 220 MeV. The effects of inhomogeneous conditions were performed for various parameters: Bragg peak position, range, penumbra width, full width at half maximum and dose of Bragg curve. A dose perturbation was observed in the region of the Bragg peak and inhomogeneous material, especially, When the bone equivalent material was inserted within the Bragg curve. However, there were no significant variations in the other parameters, except for the dose perturbation depending on the inserted location of each material. This study shows the characteristic changes in the Bragg curve due to inhomogeneous materials.

  19. The Role of Oxidative Stress in Methamphetamine-induced Toxicity and Sources of Variation in the Design of Animal Studies.

    Science.gov (United States)

    McDonnell-Dowling, Kate; Kelly, John P

    2017-01-01

    The prevalence of methamphetamine (MA) use has increased in recent years. In order to assess how this drug produces its effects, both clinical and preclinical studies have recently begun to focus on oxidative stress as an important biochemical mechanism in mediating these effects. The purpose of this review is to illustrate the variation in the design of preclinical studies investigating MA exposure on oxidative stress parameters in animal models. The experimental variables investigated and summarised include MA drug treatment, measurements of oxidative stress and antioxidant treatments that ameliorate the harmful effects of MA. These preclinical studies differ greatly in their experimental design with respect to the dose of MA (ranging between 0.25 and 20 mg/kg), the dosing regime (acute, binge or chronic), the time of measurement of oxidative stress (0.5 h to 2 wks after last MA administration), the antioxidant system targeted and finally the use of antioxidants including the route of administration (i.p. or p.o.), the frequency of exposure and the time of exposure (preventative or therapeutic). The findings in this paper suggest that there is a large diversity among these studies and so the interpretation of these results is challenging. For this reason, the development of guidelines and how best to assess oxidative stress in animal models may be beneficial. The use of these simple recommendations mean that results will be more comparable between laboratories and that future results generated will give us a greater understanding of the contribution of this important biochemical mechanism and its implications for the clinical scenario.

  20. Racial Variations in Radiation-Induced Skin Toxicity Severity: Data From a Prospective Cohort Receiving Postmastectomy Radiation

    International Nuclear Information System (INIS)

    Wright, Jean L.; Takita, Cristiane; Reis, Isildinha M.; Zhao, Wei; Lee, Eunkyung; Hu, Jennifer J.

    2014-01-01

    Purpose: Radiation-induced skin toxicity is one of the most symptomatic side effects of postmastectomy radiation therapy (PMRT). We sought to determine whether the severity of acute skin toxicity was greater in black patients in a prospective cohort receiving PMRT and to identify other predictors of more severe skin toxicity. Methods and Materials: We evaluated the first 110 patients in an ongoing prospective study assessing radiation-induced skin toxicity in patients receiving PMRT. We recorded patient demographics, body mass index (BMI), and disease and treatment characteristics. Logistic regression analyses were conducted to evaluate the effect of potential predictors on the risk of skin toxicity. Results: A total of 23.6% respondents self-identified as black, 5.5% as non-Hispanic white, 69.1% as Hispanic white, and 1.8% as other; 57% were postmenopausal, and 70.9% had BMI of >25. Median chest wall dose was 50 Gy, and mastectomy scar dose was 60 Gy. Most patients, 95.5%, were treated with a 0.5-cm bolus throughout treatment. There were no significant differences in patient characteristics in black versus non-black patients. At RT completion, moist desquamation was more common in black patients (73.1% vs 47.6%, respectively, P=.023), in postmenopausal patients (63.5% vs 40.4%, respectively, P=.016), and in those with BMI of ≥25 (60.3% vs 37.5%, respectively, P=.030). On multivariate analysis, the effects of black race (odds ratio [OR] = 7.46, P=.031), BMI ≥25 (OR = 2.95, P=.043) and postmenopausal status (OR = 8.26, P=.004) remained significant risk factors for moist desquamation. Conclusions: In this prospectively followed, racially diverse cohort of breast cancer patients receiving PMRT delivered in a uniform fashion, including the routine use of chest wall boost and bolus, black race, higher BMI, and postmenopausal status emerged as significant predictors of moist desquamation. There was a high frequency of moist desquamation, particularly in those

  1. Racial Variations in Radiation-Induced Skin Toxicity Severity: Data From a Prospective Cohort Receiving Postmastectomy Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Jean L., E-mail: jwrigh71@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); Takita, Cristiane [Department of Radiation Oncology, University of Miami Sylvester Comprehensive Cancer Center, Miami, Florida (United States); Reis, Isildinha M. [Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States); Department of Public Health Sciences, University of Miami, Miami, Florida (United States); Zhao, Wei; Lee, Eunkyung [Department of Public Health Sciences, University of Miami, Miami, Florida (United States); Hu, Jennifer J. [Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States); Department of Public Health Sciences, University of Miami, Miami, Florida (United States)

    2014-10-01

    Purpose: Radiation-induced skin toxicity is one of the most symptomatic side effects of postmastectomy radiation therapy (PMRT). We sought to determine whether the severity of acute skin toxicity was greater in black patients in a prospective cohort receiving PMRT and to identify other predictors of more severe skin toxicity. Methods and Materials: We evaluated the first 110 patients in an ongoing prospective study assessing radiation-induced skin toxicity in patients receiving PMRT. We recorded patient demographics, body mass index (BMI), and disease and treatment characteristics. Logistic regression analyses were conducted to evaluate the effect of potential predictors on the risk of skin toxicity. Results: A total of 23.6% respondents self-identified as black, 5.5% as non-Hispanic white, 69.1% as Hispanic white, and 1.8% as other; 57% were postmenopausal, and 70.9% had BMI of >25. Median chest wall dose was 50 Gy, and mastectomy scar dose was 60 Gy. Most patients, 95.5%, were treated with a 0.5-cm bolus throughout treatment. There were no significant differences in patient characteristics in black versus non-black patients. At RT completion, moist desquamation was more common in black patients (73.1% vs 47.6%, respectively, P=.023), in postmenopausal patients (63.5% vs 40.4%, respectively, P=.016), and in those with BMI of ≥25 (60.3% vs 37.5%, respectively, P=.030). On multivariate analysis, the effects of black race (odds ratio [OR] = 7.46, P=.031), BMI ≥25 (OR = 2.95, P=.043) and postmenopausal status (OR = 8.26, P=.004) remained significant risk factors for moist desquamation. Conclusions: In this prospectively followed, racially diverse cohort of breast cancer patients receiving PMRT delivered in a uniform fashion, including the routine use of chest wall boost and bolus, black race, higher BMI, and postmenopausal status emerged as significant predictors of moist desquamation. There was a high frequency of moist desquamation, particularly in those

  2. Growth-related variations in the glycosaminoglycan synthesis of ultraviolet light-induced murine cutaneous fibrosarcoma cells

    International Nuclear Information System (INIS)

    Piepkorn, M.; Carney, H.; Linker, A.

    1985-01-01

    Glycosaminoglycan synthesis was studied in cell populations of ultraviolet light-induced murine cutaneous fibrosarcoma cells under conditions of varying growth rates in vitro. After labeling with the precursors, 3 H-glucosamine and 35 SO 4 , sulfated glycosaminoglycans recoverable by direct proteolysis of the culture monolayers increased approximately 5-fold on a per cell basis from sparsely populated, exponential cell cultures (greater than 85% of cells in S, G2, or M phases) to stationary cultures inhibited by high cell density (greater than 50% of cells in G1). Within this cell surface-associated material, the relative ratio of heparan sulfate to the chondroitin sulfates was approximately 60/40% under conditions of exponential growth; in the growth-arrested cultures, the reverse ratio was found. The substratum attached material, obtained from the flask surface after ethyl glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA)-mediated detachment of the monolayers, contained relatively more hyaluronic acid, heparan sulfate, and chondroitin sulfates in the most actively proliferating cultures compared with the growth-inhibited cell populations. Furthermore, heparan sulfate and the chondroitin sulfates, which were enriched in the substratum material and in the cell pellet of exponential cultures, showed a relative shift to the cell surface-associated compartment (releasable by mild trypsinization after EGTA-mediated cell detachment) and to the compartment loosely associated with the pericellular matrix (i.e., released into the supernatant during detachment of the monolayers in the presence of EGTA)

  3. Study of the variations of fall induced hip fracture risk between right and left femurs using CT-based FEA.

    Science.gov (United States)

    Faisal, Tanvir R; Luo, Yunhua

    2017-10-03

    Hip fracture of elderly people-suffering from osteoporosis-is a severe public health concern, which can be reduced by providing a prior assessment of hip fracture risk. Image-based finite element analysis (FEA) has been considered an effective computational tool to assess the hip fracture risk. Considering the femoral neck region is the weakest, fracture risk indicators (FRI) are evaluated for both single-legged stance and sideways fall configurations and are compared between left and right femurs of each subject. Quantitative Computed Tomography (QCT) scan datasets of thirty anonymous patients' left and right femora have been considered for the FE models, which have been simulated with an equal magnitude of load applied to the aforementioned configurations. The requirement of bilateral hip assessment in predicting the fracture risk has been explored in this study. Comparing the sideways fall and single-legged stance, the FRI varies by 64 to 74% at the superior aspects and by 14 to 19% at the inferior surfaces of both the femora. The results of this in vivo analysis clearly substantiate that the fracture is expected to initiate at the superior surface of femoral neck region if a patient falls from his/her standing height. The distributions of FRI between the femurs vary considerably, and the variability is significant at the superior aspects. The p value (= 0.02) obtained from paired sample t-Test yields p value ≤ 0.05, which shows the evidence of variability of the FRI distribution between left and right femurs. Moreover, the comparison of FRIs between the left and right femur of men and women shows that women are more susceptible to hip fracture than men. The results and statistical variation clearly signify a need for bilateral hip scanning in predicting hip fracture risk, which is clinically conducted, at present, based on one hip chosen randomly and may lead to inaccurate fracture prediction. This study, although preliminary, may play a crucial role in

  4. Balkan Vegetation Database

    NARCIS (Netherlands)

    Vassilev, Kiril; Pedashenko, Hristo; Alexandrova, Alexandra; Tashev, Alexandar; Ganeva, Anna; Gavrilova, Anna; Gradevska, Asya; Assenov, Assen; Vitkova, Antonina; Grigorov, Borislav; Gussev, Chavdar; Filipova, Eva; Aneva, Ina; Knollová, Ilona; Nikolov, Ivaylo; Georgiev, Georgi; Gogushev, Georgi; Tinchev, Georgi; Pachedjieva, Kalina; Koev, Koycho; Lyubenova, Mariyana; Dimitrov, Marius; Apostolova-Stoyanova, Nadezhda; Velev, Nikolay; Zhelev, Petar; Glogov, Plamen; Natcheva, Rayna; Tzonev, Rossen; Boch, Steffen; Hennekens, Stephan M.; Georgiev, Stoyan; Stoyanov, Stoyan; Karakiev, Todor; Kalníková, Veronika; Shivarov, Veselin; Russakova, Veska; Vulchev, Vladimir

    2016-01-01

    The Balkan Vegetation Database (BVD; GIVD ID: EU-00-019; http://www.givd.info/ID/EU-00- 019) is a regional database that consists of phytosociological relevés from different vegetation types from six countries on the Balkan Peninsula (Albania, Bosnia and Herzegovina, Bulgaria, Kosovo, Montenegro

  5. Soil and vegetation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

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

  6. Salt-induced variation in some potential physiochemical attributes of two genetically diverse spring wheat (triticum aestivum L.) cultivars: photosynthesis and photosystem II efficiency

    International Nuclear Information System (INIS)

    Ashraf, M.A.; Ashraf, M.

    2011-01-01

    Variation in salt tolerance potential of two contrasting wheat cultivars (salt tolerant S-24 and moderately salt sensitive MH-97) at different growth stages was observed when these wheat cultivars were exposed to salinity stress in hydroponic culture. Salinity caused a marked reduction in photosynthetic pigments, transpiration and photos synthetic rates, and stomatal conductance at early growth stages in both wheat cultivars, being more prominent in cv. MH-97. In addition, a marked salt-induced alteration was observed in different attributes of chlorophyll fluorescence. On the basis of physiological characterization of these two wheat cultivars at different growth stages, it was inferred that cv. S-24 exhibited higher salinity tolerance at all growth stages in terms of less salinity-induced degradation of photosynthetic pigments, higher photosynthetic rates, maintenance of photosystem II under salinity stress as compared to that in cv. MH-97. In view of the results presented here, it is evident that wheat plants were prone to adverse effects of salinity at early growth stages as compared to later growth stages. (author)

  7. Molecular systematics of pinniped hookworms (Nematoda: Uncinaria): species delimitation, host associations and host-induced morphometric variation.

    Science.gov (United States)

    Nadler, Steven A; Lyons, Eugene T; Pagan, Christopher; Hyman, Derek; Lewis, Edwin E; Beckmen, Kimberlee; Bell, Cameron M; Castinel, Aurelie; Delong, Robert L; Duignan, Padraig J; Farinpour, Cher; Huntington, Kathy Burek; Kuiken, Thijs; Morgades, Diana; Naem, Soraya; Norman, Richard; Parker, Corwin; Ramos, Paul; Spraker, Terry R; Berón-Vera, Bárbara

    2013-12-01

    host species representing the more recent host-parasite association. Intraspecific host-induced size differences are inconsistent with the exclusive use of morphometrics to delimit and diagnose species of Uncinaria from pinnipeds. Copyright © 2013 Australian Society for Parasitology Inc. All rights reserved.

  8. Reduced task-induced variations in the distribution of activity across back muscle regions in individuals with low back pain.

    Science.gov (United States)

    Falla, Deborah; Gizzi, Leonardo; Tschapek, Marika; Erlenwein, Joachim; Petzke, Frank

    2014-05-01

    This study investigated change in the distribution of lumbar erector spinae muscle activity and pressure pain sensitivity across the low back in individuals with low back pain (LBP) and healthy controls. Surface electromyographic (EMG) signals were recorded from multiple locations over the lumbar erector spinae muscle with a 13×5 grid of electrodes from 19 people with chronic nonspecific LBP and 17 control subjects as they performed a repetitive lifting task. The EMG root mean square (RMS) was computed for each location of the grid to form a map of the EMG amplitude distribution. Pressure pain thresholds (PPT) were recorded before and after the lifting task over a similar area of the back. For the control subjects, the EMG RMS progressively increased more in the caudal region of the lumbar erector spinae during the repetitive task, resulting in a shift in the distribution of muscle activity. In contrast, the distribution of muscle activity remained unaltered in the LBP group despite an overall increase in EMG amplitude. PPT was lower in the LBP group after completion of the repetitive task compared to baseline (average across all locations: pre: 268.0±165.9 kPa; post: 242.0±166.7 kPa), whereas no change in PPT over time was observed for the control group (320.1±162.1 kPa; post: 322.0±179.5 kPa). The results demonstrate that LBP alters the normal adaptation of lumbar erector spinae muscle activity to exercise, which occurs in the presence of exercise-induced hyperalgesia. Reduced variability of muscle activity may have important implications for the provocation and recurrence of LBP due to repetitive tasks. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  9. Association of genetic variations in FOXO3 gene with susceptibility to noise induced hearing loss in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Haoran Guo

    Full Text Available Noise induced hearing loss (NIHL, a multifactorial disease involving both genetic and environmental factors, is one of the most important occupational health hazards. Nonetheless, the influence of FOXO3 variants on NIHL risk have not been illuminated. This research was conducted to explore the effects of FOXO3 polymorphisms on individual susceptibility to NIHL. A total of 2689 industrial workers from one textile factory of east China were recruited to participate in the current research. Venous blood was collected, questionnaire and pure-tone audiometry (PTA was conducted by specialist physicians. Then, we performed genotyping of three selected SNPs (rs2802292, rs10457180, and rs12206094 in FOXO3 gene in 566 NIHL patients and 566 controls. Subsequently, the main effects of genotype and its interactions were evaluated. Our results revealed that individuals with the G allele of rs2802292, G allele of rs10457180, T allele of rs12206094 (OR = 1.43, 1.43, and 1.31 respectively and the haplotype GAC and others (TGT/GGT/GGC/GAT (rs2802292-rs10457180-rs12206094 (OR = 1.49 and 2.09 respectively are associated with an increased risk of NIHL in a Chinese population. Stratified analysis showed that an increased NIHL risk was found in the subjects who exposed to noise >16 years with rs2802292 GG/GT and rs10457180 AG/GG genotype with an OR of 1.62 and 1.66 respectively. Multifactor dimensionality reduction analysis indicated that rs10457180, rs2802292, and rs12206094 have interactions and are related to increased NIHL risk (OR = 1.53. The genetic polymorphism rs2802292, rs10457180, and rs12206094 within FOXO3 gene are associated with an increased risk of NIHL in a Chinese population and have potential to be biomarkers for noise exposed workers.

  10. Stress and Damage Induced Gas Flow Pattern and Permeability Variation of Coal from Songzao Coalfield in Southwest China

    Directory of Open Access Journals (Sweden)

    Minghui Li

    2016-05-01

    Full Text Available The permeability of coal is a critical parameter in estimating the performance of coal reservoirs. Darcy’s law describes the flow pattern that the permeability has a linear relationship with the flow velocity. However, the stress induced deformation and damage can significantly influence the gas flow pattern and permeability of coal. Coals from Songzao coalfield in Chongqing, southwest China were collected for the study. The gas flow velocities under different injection gas pressures and effective stresses in the intact coal and damaged coal were tested using helium, incorporating the role of gas flow pattern on the permeability of coal. The relationships between the flow velocity and square of gas pressure gradient were discussed, which can help us to investigate the transformation conditions of gas linear flow and gas nonlinear flow in the coal. The results showed that the gas flow in the intact coal existed pseudo-initial flow rate under low effective stress. The low-velocity non-Darcy gas flow gradually occurred and the start-up pressure gradient increased in the coal as the effective stress increased. The gas flow rate in the damaged coal increased nonlinearly as the square of pressure gradient increased under low effective stress. The instability of gas flow caused by high ratio of injection gas pressure over effective stress in the damaged coal contributed to the increase of the gas flow rate. As the effective stress increased, the increase of gas flow rate in coal turned to be linear. The mechanisms of the phenomena were explored according to the experimental results. The permeability of coal was corrected based on the relationships between the flow velocity and square of gas pressure gradient, which showed advantages in accurately estimating the performance of coal reservoirs.

  11. The TreadWheel: A Novel Apparatus to Measure Genetic Variation in Response to Gently Induced Exercise for Drosophila.

    Directory of Open Access Journals (Sweden)

    Sean Mendez

    Full Text Available Obesity is one of the dramatic health issues affecting developed and developing nations, and exercise is a well-established intervention strategy. While exercise-by-genotype interactions have been shown in humans, overall little is known. Using the natural negative geotaxis of Drosophila melanogaster, an important model organism for the study of genetic interactions, a novel exercise machine, the TreadWheel, can be used to shed light on this interaction. The mechanism for inducing exercise with the TreadWheel is inherently gentle, thus minimizing possible confounding effects of other stressors. Using this machine, we were able to assess large cohorts of adult flies from eight genetic lines for their response to exercise after one week of training. We measured their triglyceride, glycerol, protein, glycogen, glucose content, and body weight, as well as their climbing ability and feeding behavior in response to exercise. Exercised flies showed decreased stored triglycerides, glycogen, and body weight, and increased stored protein and climbing ability. In addition to demonstrating an overall effect of TreadWheel exercise on flies, we found significant interactions of exercise with genotype, sex, or genotype-by-sex effects for most of the measured phenotypes. We also observed interaction effects between exercise, genotype, and tissue (abdomen or thorax for metabolite profiles, and those differences can be partially linked to innate differences in the flies' persistence in maintaining activity during exercise bouts. In addition, we assessed gene expression levels for a panel of 13 genes known to be associated with respiratory fitness and found that many responded to exercise. With this study, we have established the TreadWheel as a useful tool to study the effect of exercise in flies, shown significant genotype-specific and sex-specific impacts of exercise, and have laid the ground work for more extensive studies of how genetics, sex, environment

  12. The TreadWheel: A Novel Apparatus to Measure Genetic Variation in Response to Gently Induced Exercise for Drosophila

    Science.gov (United States)

    Mendez, Sean; Watanabe, Louis; Hill, Rachel; Owens, Meredith; Moraczewski, Jason; Rowe, Glenn C.; Riddle, Nicole C.

    2016-01-01

    Obesity is one of the dramatic health issues affecting developed and developing nations, and exercise is a well-established intervention strategy. While exercise-by-genotype interactions have been shown in humans, overall little is known. Using the natural negative geotaxis of Drosophila melanogaster, an important model organism for the study of genetic interactions, a novel exercise machine, the TreadWheel, can be used to shed light on this interaction. The mechanism for inducing exercise with the TreadWheel is inherently gentle, thus minimizing possible confounding effects of other stressors. Using this machine, we were able to assess large cohorts of adult flies from eight genetic lines for their response to exercise after one week of training. We measured their triglyceride, glycerol, protein, glycogen, glucose content, and body weight, as well as their climbing ability and feeding behavior in response to exercise. Exercised flies showed decreased stored triglycerides, glycogen, and body weight, and increased stored protein and climbing ability. In addition to demonstrating an overall effect of TreadWheel exercise on flies, we found significant interactions of exercise with genotype, sex, or genotype-by-sex effects for most of the measured phenotypes. We also observed interaction effects between exercise, genotype, and tissue (abdomen or thorax) for metabolite profiles, and those differences can be partially linked to innate differences in the flies' persistence in maintaining activity during exercise bouts. In addition, we assessed gene expression levels for a panel of 13 genes known to be associated with respiratory fitness and found that many responded to exercise. With this study, we have established the TreadWheel as a useful tool to study the effect of exercise in flies, shown significant genotype-specific and sex-specific impacts of exercise, and have laid the ground work for more extensive studies of how genetics, sex, environment, and aging interact

  13. Water quality function of an extensive vegetated roof.

    Science.gov (United States)

    Todorov, Dimitar; Driscoll, Charles T; Todorova, Svetoslava; Montesdeoca, Mario

    2018-06-01

    In this paper we present the results of a four-year study of water quality in runoff from an extensive, sedum covered, vegetated roof on an urban commercial building. Monitoring commenced seven months after the roof was constructed, with the first growing season. Stormwater drainage quality function of the vegetated roof was compared to a conventional (impermeable, high-albedo) membrane roof in addition to paired measurements of wet and bulk depositions at the study site. We present concentrations and fluxes of nutrients and major solutes. We discuss seasonal and year-to-year variation in water quality of drainage from the vegetated roof and how it compares with atmospheric deposition and drainage from the impermeable roof. Drainage waters from the vegetated roof exhibited a high concentration of nutrients compared to atmospheric deposition, particularly during the warm temperature growing season. However, nutrient losses were generally low because of the strong retention of water by the vegetated roof. There was marked variation in the retention of nutrients by season due to variations in concentrations in drainage from the vegetated roof. The vegetated roof was a sink of nitrogen, total phosphorus and chloride, and a source of phosphate and dissolved inorganic and organic carbon. Chloride exhibited elevated inputs and leaching during the winter. The drainage from the vegetated and impermeable roofs met the United States Environmental Protection Agency freshwater standards for all parameters, except for total phosphorus. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Method of producing vegetable puree

    DEFF Research Database (Denmark)

    2004-01-01

    A process for producing a vegetable puree, comprising the sequential steps of: a)crushing, chopping or slicing the vegetable into pieces of 1 to 30 mm; b) blanching the vegetable pieces at a temperature of 60 to 90°C; c) contacted the blanched vegetable pieces with a macerating enzyme activity; d......) blending the macerated vegetable pieces and obtaining a puree....

  15. Vegetation survey: a new focus for Applied Vegetation Science

    NARCIS (Netherlands)

    Chytry, M.; Schaminee, J.H.J.; Schwabe, A.

    2011-01-01

    Vegetation survey is an important research agenda in vegetation science. It defines vegetation types and helps understand differences among them, which is essential for both basic ecological research and applications in biodiversity conservation and environmental monitoring. In this editorial, we

  16. Association between educational level and vegetable use in nine European countries

    NARCIS (Netherlands)

    Prättälä, Ritva; Hakala, Samu; Roskam, Albert-Jan R.; Roos, Eva; Helmert, Uwe; Klumbiene, Jurate; van Oyen, Herman; Regidor, Enrique; Kunst, Anton E.

    2009-01-01

    OBJECTIVE: The relationship of socio-economic status and vegetable consumption is examined in nine European countries. The aim is to analyse whether the pattern of socio-economic variation with regard to vegetable consumption is similar in all studied countries with high v. low vegetable

  17. Modeling the influence of the BRDF characteristics of vegetation on the retrieval of solar-induced chlorophyll fluorescence under different illumination conditions

    Science.gov (United States)

    Liu, Xinjie; Liu, Liangyun

    2017-04-01

    The Fraunhofer Line Discrimination (FLD) principle is the main approach used for the retrieval of solar-induced chlorophyll fluorescence (SIF). The basic assumption of the FLD principle is that the apparent reflectance spectra without SIF in-filling are smooth in the region of the absorption bands. However, in fact, this assumption is not valid due to the so-called "direct radiation in-filling" effect caused by the non-linear contribution of direct and diffuse radiation at the oxygen absorption bands, which are widely used for ground-based SIF retrieval. In this study, we first analyzed the physical mechanism of the direct radiation in-filling effect on the oxygen absorption bands and found that the bias in the SIF retrieval caused by the direct radiation in-filling effect at the O2-A band was less than 20% based on the use of a simulated dataset. Secondly, we established a simple correction model of the direct radiation in-filling effect. We found that the direct radiation in-filling effect at the O2-A band was directly proportional to the difference between the reflectance of the direct and diffuse radiation, and that the coefficient of proportionality was well correlated with the diffuse-to-global radiation ratio in the form of a quadratic function. The coefficient of determination (R-squared) for this correlation was 0.97. Finally, the model was validated using both simulated and field datasets. The validation results show that the bias in the SIF retrieval caused by the direct radiation in-filling effect can be efficiently corrected using the model proposed in this paper. This study thus provides a possible approach to estimating and correcting for the direct radiation-infilling effect using prior knowledge of the BRDF characteristics of direct and diffuse radiation for specific targets.

  18. Vegetation Identification With LIDAR

    National Research Council Canada - National Science Library

    Helt, Michael F

    2005-01-01

    .... The specific terrain element of interest is vegetation, and in particular, tree type. Data taken on April 12th, 2005, were taken over a 10 km 20 km region which is mixed use agriculture and wetlands...

  19. Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions

    Science.gov (United States)

    Ghimire, Bardan; Williams, Christopher A.; Collatz, George James; Vanderhoof, Melanie

    2012-01-01

    The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually.

  20. Leaf-Like Sepals Induced by Ectopic Expression of a SHORT VEGETATIVE PHASE (SVP)-Like MADS-Box Gene from the Basal Eudicot Epimedium sagittatum

    Science.gov (United States)

    Li, Zhineng; Zeng, Shaohua; Li, Yanbang; Li, Mingyang; Souer, Erik

    2016-01-01

    Epimedium L. (Berberidaceae, Ranales), a perennial traditional Chinese medicinal herb, has become a new popular landscape plant for ground cover and pot culture in many countries based on its excellent ornamental characteristics and, distinctive and diverse floral morphology. However, little is known about the molecular genetics of flower development in Epimedium sagittatum. Here, we describe the characterization of EsSVP that encodes a protein sharing 68, 54, and 35% similarity with SVP, AGAMOUS-like 24 (AGL24) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) in Arabidopsis, respectively. Quantitative RT-PCR (qRT-PCR) indicated that EsSVP transcripts were principally found in petiole and leaf tissues, with little expression in roots and flowers and no in fruits. The highest EsSVP expression was observed in leaves. The flowering time of 35S::EsSVP in most Arabidopsis thaliana and in all petunia plants was not affected in both photoperiod conditions, but 35S::EsSVP 5# and 35S::EsSVP 1# Arabidopsis lines induced late and early flowering under long day (LD, 14 h light/10 h dark) and short day (SD, 10 h light/14 h dark) conditions, respectively. The 35S::EsSVP Arabidopsis produced extra secondary inflorescence or floral meristems in the axils of the leaf-like sepals with excrescent trichomes, and leaf-like sepals not able to enclose the inner three whorls completely. Moreover, almost all transgenic Arabidopsis plants showed persistent sepals around the completely matured fruits. Upon ectopic expression of 35S::EsSVP in Petunia W115, sepals were enlarged, sometimes to the size of leaves; corollas were greenish and did not fully open. These results suggest that EsSVP is involved in inflorescence meristem identity and flowering time regulation in some conditions. Although, the SVP homologs might have suffered functional diversification among diverse species between core and basal eudicots, the protein functions are conserved between Arabidopsis/Petunia and Epimedium

  1. Leaf-like sepals induced by ectopic expression of a SHORT VEGETATIVE PHASE (SVP-like MADS-box gene from the basal eudicot Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Zhineng Li

    2016-09-01

    Full Text Available Epimedium L. (Berberidaceae, Ranales, a perennial traditional Chinese medicinal herb, has become a new popular landscape plant for ground cover and pot culture in many countries based on its excellent ornamental characteristics and, distinctive and diverse floral morphology. However, little is known about the molecular genetics of flower development in Epimedium sagittatum. Here, we describe the characterization of EsSVP that encodes a protein sharing 68%, 54% and 35% similarity with SVP, AGAMOUS-like 24 (AGL24 and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1 in Arabidopsis, respectively. Quantitative RT-PCR (qRT-PCR indicated that EsSVP transcripts were principally found in petiole and leaf tissues, with little expression in roots and flowers and no in fruits. The highest EsSVP expression was observed in leaves. The flowering time of 35S::EsSVP in most Arabidopsis thaliana and in all petunia plants was not affected in both photoperiod conditions, but 35S::EsSVP 5# and 35S::EsSVP 1# Arabidopsis lines induced late and early flowering under long day (LD, 14 hr light/10 hr dark and short day (SD, 10 hr light/14 hr dark conditions, respectively. The 35S::EsSVP Arabidopsis produced extra secondary inflorescence or floral meristems in the axils of the leaf-like sepals with excrescent trichomes, and leaf-like sepals not able to enclose the inner three whorls completely. Moreover, almost all transgenic Arabidopsis plants showed persistent sepals around the completely matured fruits. Upon ectopic expression of 35S::EsSVP in Petunia W115, sepals were enlarged, sometimes to the size of leaves; corollas were greenish and did not fully open. These results suggest that EsSVP is involved in inflorescence meristem identity and flowering time regulation in some conditions. Although the SVP homologs might have suffered functional diversification among diverse species between core and basal eudicots, the protein functions are conserved between Arabidopsis

  2. New views on changing Arctic vegetation

    Science.gov (United States)

    Kennedy, Robert E.

    2012-03-01

    . Environ. 114 183-98 IPCC 2007 Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change ed Core Writing Team, R K Pachauri and A Reisinger (Geneva: IPCC) Kennedy R E, Yang Z and Cohen W B 2010 Detecting trends in forest disturbance and recovery using yearly Landsat time series: 1. LandTrendr—Temporal segmentation algorithms Remote Sens. Environ. 114 2897-910 Klady R A, Henry G H R and Lemay V 2011 Changes in high Arctic tundra plant reproduction in response to long-term experimental warming Glob. Change Biol. 17 1611-24 Lenihan J M, Bachelet D, Neilson R P and Drapek R 2008 Simulated response of conterminous United States ecosystems to climate change at different levels of fire suppression, CO2 emission rate, and growth response to CO2 Glob. Planet. Change 64 16-25 Masek J G 2001 Stability of boreal forest stands during recent climate change: evidence from Landsat satellite imagery J. Biogeogr. 28 967-76 Myneni R B, Tucker C J, Asrar G and Keeling C D 1998 Interannual variations in satellite-sensed vegetation index data from 1981 to 1991 J. Geophys. Res.—Atmos. 103 6145-60 Pieper S J, Loewen V, Gill M and Johnstone J F 2011 Plant responses to natural and experimental variations in temperature in Alpine Tundra, Southern Yukon, Canada, Arct. Antarct. Alp. Res. 43 442-56 Potapov P V, Turubanova S and Hansen M C 2011 Regionals-scale boreal forest cover and change mapping using Landsat data composites for European Russia Remote Sens. Environ. 115 548-61 Ranson K J, Sun G, Kharuk V I and Kovacs K 2004 Assessing tundra-taiga boundary with multi-sensor satellite data Remote Sens. Environ. 93 283-95 Scheller R M and Mladenoff D J 2005 A spatially interactive simulation of climate change, harvesting, wind, and tree species migration and projected changes to forest composition and biomass in northern Wisconsin, USA Glob. Change Biol. 11 307-21 Seastedt T R, Bowman W D

  3. Light-induced Variation in Phenolic Compounds in Cabernet Sauvignon Grapes (Vitis vinifera L.) Involves Extensive Transcriptome Reprogramming of Biosynthetic Enzymes, Transcription Factors, and Phytohormonal Regulators.

    Science.gov (United States)

    Sun, Run-Ze; Cheng, Guo; Li, Qiang; He, Yan-Nan; Wang, Yu; Lan, Yi-Bin; Li, Si-Yu; Zhu, Yan-Rong; Song, Wen-Feng; Zhang, Xue; Cui, Xiao-Di; Chen, Wu; Wang, Jun

    2017-01-01

    Light environments have long been known to influence grape ( Vitis vinifera L.) berry development and biosynthesis of phenolic compounds, and ultimately affect wine quality. Here, the accumulation and compositional changes of hydroxycinnamic acids (HCAs) and flavonoids, as well as global gene expression were analyzed in Cabernet Sauvignon grape berries under sunlight exposure treatments at different phenological stages. Sunlight exposure did not consistently affect the accumulation of berry skin flavan-3-ol or anthocyanin among different seasons due to climatic variations, but increased HCA content significantly at véraison and harvest, and enhanced flavonol accumulation dramatically with its timing and severity degree trend. As in sunlight exposed berries, a highly significant correlation was observed between the expression of genes coding phenylalanine ammonia-lyase, 4-coumarate: CoA ligase, flavanone 3-hydroxylase and flavonol synthase family members and corresponding metabolite accumulation in the phenolic biosynthesis pathway, which may positively or negatively be regulated by MYB, bHLH, WRKY, AP2/EREBP, C2C2, NAC, and C2H2 transcription factors (TFs). Furthermore, some candidate genes required for auxin, ethylene and abscisic acid signal transductions were also identified which are probably involved in berry development and flavonoid biosynthesis in response to enhanced sunlight irradiation. Taken together, this study provides a valuable overview of the light-induced phenolic metabolism and transcriptome changes, especially the dynamic responses of TFs and signaling components of phytohormones, and contributes to the further understanding of sunlight-responsive phenolic biosynthesis regulation in grape berries.

  4. Light-induced Variation in Phenolic Compounds in Cabernet Sauvignon Grapes (Vitis vinifera L.) Involves Extensive Tr