Deciphering the Costs of Reproduction in Mango – Vegetative Growth Matters

PubMed Central

Capelli, Mathilde; Lauri, Pierre-Éric; Normand, Frédéric

2016-01-01

Irregular fruit production across successive years is a major issue that limits the profitability of most temperate and tropical fruit crops. It is particularly affected by the reciprocal relationships between vegetative and reproductive growth. The concept of the costs of reproduction is defined in terms of losses in the potential future reproductive success caused by current investment in reproduction. This concept, developed in ecology and evolutionary biology, could provide a methodological framework to analyze irregular bearing in fruit crops, especially in relation to the spatial scale at which studies are done. The objective of this study was to investigate the direct effects of reproduction during a growing cycle on reproduction during the following growing cycle and the indirect effects through vegetative growth between these two reproductive events, for four mango cultivars and during two growing cycles. Two spatial scales were considered: the growth unit (GU) and the scaffold branch. Costs of reproduction were detected between two successive reproductive events and between reproduction and vegetative growth. These costs were scale-dependent, generally detected at the GU scale and infrequently at the scaffold branch scale, suggesting partial branch autonomy with respect to processes underlying the effects of reproduction on vegetative growth. In contrast, the relationships between vegetative growth and reproduction were positive at the GU scale and at the scaffold branch scale in most cases, suggesting branch autonomy for the processes, mainly local, underlying flowering and fruiting. The negative effect of reproduction on vegetative growth prevailed over the positive effect of vegetative growth on the subsequent reproduction. The costs of reproduction were also cultivar-dependent. Those revealed at the GU scale were related to the bearing behavior of each cultivar. Our results put forward the crucial role of vegetative growth occurring between two

Early vegetation development on an exposed reservoir: implications for dam removal.

PubMed

Auble, Gregor T; Shafroth, Patrick B; Scott, Michael L; Roelle, James E

2007-06-01

The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical of riparian zones and reservoir sediment of shallow dams and (2) a shift in moisture status from mesic to the xeric conditions associated with the pre-impoundment upland position of most of the drawdown zone. Plant communities changed rapidly during the first four years of exposure, but were still substantially different from the background upland plant community. Predictions from the recruitment box model about the locations of Populus deltoides subsp. monilifera (plains cottonwood) seedlings relative to the water surface were qualitatively confirmed with respect to optimum locations. However, the extreme vertical range of water surface elevations produced cottonwood seed regeneration well outside the predicted limits of drawdown rate and height above late summer stage. The establishment and survival of cottonwood at high elevations and the differences between the upland plant community and the community that had developed after four years of exposure suggest that vegetation recovery following tall dam removal will follow a trajectory very different from a simple reversal of the response to dam construction, involving not only long time scales of establishment and growth of upland vegetation, but also possibly decades of persistence of legacy vegetation established during the reservoir to upland transition.

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

PubMed Central

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

2008-01-01

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

Early vegetation development on an exposed reservoir: Implications for dam removal

USGS Publications Warehouse

Auble, G.T.; Shafroth, P.B.; Scott, M.L.; Roelle, J.E.

2007-01-01

The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical of riparian zones and reservoir sediment of shallow dams and (2) a shift in moisture status from mesic to the xeric conditions associated with the pre-impoundment upland position of most of the drawdown zone. Plant communities changed rapidly during the first four years of exposure, but were still substantially different from the background upland plant community. Predictions from the recruitment box model about the locations of Populus deltoides subsp. monilifera (plains cottonwood) seedlings relative to the water surface were qualitatively confirmed with respect to optimum locations. However, the extreme vertical range of water surface elevations produced cottonwood seed regeneration well outside the predicted limits of drawdown rate and height above late summer stage. The establishment and survival of cottonwood at high elevations and the differences between the upland plant community and the community that had developed after four years of exposure suggest that vegetation recovery following tall dam removal will follow a trajectory very different from a simple reversal of the response to dam construction, involving not only long time scales of establishment and growth of upland vegetation, but also possibly decades of persistence of legacy vegetation established during the reservoir to upland transition. ?? 2007 Springer Science+Business Media, LLC.

Early Pliocene vegetation distribution in Europe

NASA Astrophysics Data System (ADS)

Popescu, S.; Warny, S.; Suc, J.

2010-12-01

The Early Pliocene corresponds to a global warm climate documented by marine & terrestrial records. Reconstruction of climatic parameters, based on terrestrial proxies, indicate at European mid-latitudes a MAT higher of about 1-5°C than today and MAP higher of about 400-1000 mm. This global warm situation was interrupted between 4.7 - 4.5 Ma by a cooling event related to small fluctuations of the Antarctic ice-sheet that modify the floristic assemblages. according to pollen recors, the Northern Mediterranean area is characterized by dominance of arboreal pollen, suggesting a dense forest cover, on contrary to the Southern Mediterranean where herbs were prevalent, signifying a widespread development of open vegetation during the early Pliocene. Such a contrast in landscape between the North and the South of the Mediterranean is to be related to the latitudinal gradient in humidity. In the North Mediterranean area, the vegetation organization was also closely linked to the relief. Coastal plains were inhabited by Taxodiaceae swamps replaced in some places by marshes. With respect to the geographic position, several plant ecosystems can distinguished: (1) salt marshes, along the Atlantic coastline (zone A); (2) marshes mostly made of Cyperaceae evidenced on the Mediterranean coastline. Such juxtaposed assemblages resemble the modern vegetation of the Mississippi Delta and Florida. Peculiar vegetation assemblages characterize the Mediterranean coastal plains. In the southeastern Mediterranean region (Zone B), the open vegetation was composed by herbs including subdesertic elements. Mediterranean xerophytes are only numerically represented in the area of Tarragona and Sicily, their assemblage resemble the modern thermo-mediterranean formation. Close to the mountains (Zone C) vegetation is organized according to an altitudinal gradient. The low altitude vegetation was composed by Taxodiaceae (Sequoia) while Cathaya and Cedrus dominated the mid-altitude belt. Abies and

Preliminary estimation of the realistic optimum temperature for vegetation growth in China.

PubMed

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

Preliminary Estimation of the Realistic Optimum Temperature for Vegetation Growth in China

NASA Astrophysics Data System (ADS)

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

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

NASA Technical Reports Server (NTRS)

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.

Contrasting growth responses of dominant peatland plants to warming and vegetation composition.

PubMed

Walker, Tom N; Ward, Susan E; Ostle, Nicholas J; Bardgett, Richard D

2015-05-01

There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and vegetation change are unknown. Here, we used a field warming and vegetation removal experiment to test the hypothesis that dominant species from the three plant functional types present (dwarf-shrubs: Calluna vulgaris; graminoids: Eriophorum vaginatum; bryophytes: Sphagnum capillifolium) contrast in their growth responses to warming and the presence or absence of other plant functional types. Warming was accomplished using open top chambers, which raised air temperature by approximately 0.35 °C, and we measured air and soil microclimate as potential mechanisms through which both experimental factors could influence growth. We found that only Calluna growth increased with experimental warming (by 20%), whereas the presence of dwarf-shrubs and bryophytes increased growth of Sphagnum (46%) and Eriophorum (20%), respectively. Sphagnum growth was also negatively related to soil temperature, which was lower when dwarf-shrubs were present. Dwarf-shrubs may therefore promote Sphagnum growth by cooling the peat surface. Conversely, the effect of bryophyte presence on Eriophorum growth was not related to any change in microclimate, suggesting other factors play a role. In conclusion, our findings reveal contrasting abiotic and biotic controls over dominant peatland plant growth, suggesting that community composition and carbon cycling could be modified by simultaneous climate and vegetation change.

Retrieval of wheat growth parameters with radar vegetation indices

USDA-ARS?s Scientific Manuscript database

The Radar Vegetation Index (RVI) has a low sensitivity to changes in environmental conditions and has the potential as a tool to monitor the vegetation growth. In this study, we expand on previous research by investigating the radar response over a wheat canopy. RVI was computed using observations m...

Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in Magnaporthe oryzae.

PubMed

Geoghegan, Ivey A; Gurr, Sarah J

2017-09-01

Chitin deacetylation results in the formation of chitosan, a polymer of β1,4-linked glucosamine. Chitosan is known to have important functions in the cell walls of a number of fungal species, but its role during hyphal growth has not yet been investigated. In this study, we have characterized the role of chitin deacetylation during vegetative hyphal growth in the filamentous phytopathogen Magnaporthe oryzae. We found that chitosan localizes to the septa and lateral cell walls of vegetative hyphae and identified 2 chitin deacetylases expressed during vegetative growth-CDA1 and CDA4. Deletion strains and fluorescent protein fusions demonstrated that CDA1 is necessary for chitin deacetylation in the septa and lateral cell walls of mature hyphae in colony interiors, whereas CDA4 deacetylates chitin in the hyphae at colony margins. However, although the Δcda1 strain was more resistant to cell wall hydrolysis, growth and pathogenic development were otherwise unaffected in the deletion strains. The role of chitosan hydrolysis was also investigated. A single gene encoding a putative chitosanase (CSN) was discovered in M. oryzae and found to be expressed during vegetative growth. However, chitosan localization, vegetative growth, and pathogenic development were unaffected in a CSN deletion strain, rendering the role of this enzyme unclear. © 2017 The Authors Cellular Microbiology Published by John Wiley & Sons Ltd.

Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in Magnaporthe oryzae

PubMed Central

Geoghegan, Ivey A.

2017-01-01

Summary Chitin deacetylation results in the formation of chitosan, a polymer of β1,4‐linked glucosamine. Chitosan is known to have important functions in the cell walls of a number of fungal species, but its role during hyphal growth has not yet been investigated. In this study, we have characterized the role of chitin deacetylation during vegetative hyphal growth in the filamentous phytopathogen Magnaporthe oryzae. We found that chitosan localizes to the septa and lateral cell walls of vegetative hyphae and identified 2 chitin deacetylases expressed during vegetative growth—CDA1 and CDA4. Deletion strains and fluorescent protein fusions demonstrated that CDA1 is necessary for chitin deacetylation in the septa and lateral cell walls of mature hyphae in colony interiors, whereas CDA4 deacetylates chitin in the hyphae at colony margins. However, although the Δcda1 strain was more resistant to cell wall hydrolysis, growth and pathogenic development were otherwise unaffected in the deletion strains. The role of chitosan hydrolysis was also investigated. A single gene encoding a putative chitosanase (CSN) was discovered in M. oryzae and found to be expressed during vegetative growth. However, chitosan localization, vegetative growth, and pathogenic development were unaffected in a CSN deletion strain, rendering the role of this enzyme unclear. PMID:28371146

Growth from Spores of Nonproteolytic Clostridium botulinum in Heat-Treated Vegetable Juice

PubMed Central

Stringer, Sandra C.; Haque, Nuzrul; Peck, Michael W.

1999-01-01

Unheated spores of nonproteolytic Clostridium botulinum were able to lead to growth in sterile deoxygenated turnip, spring green, helda bean, broccoli, or potato juice, although the probability of growth was low and the time to growth was longer than the time to growth in culture media. With all five vegetable juices tested, the probability of growth increased when spores were inoculated into the juice and then heated for 2 min in a water bath at 80°C. The probability of growth was greater in bean or broccoli juice than in culture media following 10 min of heat treatment in these media. Growth was prevented by heat treatment of spores in vegetable juices or culture media at 80°C for 100 min. We show for the first time that adding heat-treated vegetable juice to culture media can increase the number of heat-damaged spores of C. botulinum that can lead to colony formation. PMID:10224012

Drought impact on vegetation growth and mortality

NASA Astrophysics Data System (ADS)

Xu, C.; Wang, M.; Allen, C. D.; McDowell, N. G.; Middleton, R. S.

2017-12-01

Vegetation is a key regulator of the global carbon cycle via CO2 absorption through photosynthesis and subsequent growth; however, low water availability, heat stress, and disturbances associated with droughts could substantially reduce vegetation growth and increase vegetation mortality. As far as we know, there are few studies have assessed the drought impact on vegetation growth and mortality at regional and global scales. In this study, we analyzed 13 Earth System models (ESMs) to quantify the impact of drought on GPP and linked the remote-sensing based tree mortality to observed drought indices to assess the drought impact on tree mortality in continental US (CONUS). Our analysis of 13 Earth System models (ESMs) shows that the average global gross primary production (GPP) reduction per year associated with extreme droughts over years 2075-2099 is predicted to be 3-5 times larger than that over years 1850-1999. The annual drought-associated reduction in GPP over years 2075-2099 could be 52 and 74 % of annual fossil fuel carbon emission during years 2000-2007. Increasing drought impacts on GPP are driven primarily by the increasing drought frequency. The risks of drought-associated GPP reduction are particularly high for temperate and tropical regions. The consistent prediction of higher drought-associated reduction in NPP across 13 ESMs suggests increasing impacts of drought on the global carbon cycle with atmospheric warming. Our analysis of drought impact on tree mortality showed that drought-associated carbon loss accounts for 12% of forest carbon loss in CONUS for 2000-2014, which is about one-fifth of that resulting from timber harvesting and 1.35 % of average annual fossil fuel emissions in the U.S. for the same period. The carbon stock loss from natural disturbances for 2000-2014 is approximately 75% of the total carbon loss from anthropogenic disturbance (timber harvesting), suggesting that natural disturbances play a very important role on forest

Contrasting shrub species respond to early summer temperatures leading to correspondence of shrub growth patterns

NASA Astrophysics Data System (ADS)

Weijers, Stef; Pape, Roland; Löffler, Jörg; Myers-Smith, Isla H.

2018-03-01

The Arctic-alpine biome is warming rapidly, resulting in a gradual replacement of low statured species by taller woody species in many tundra ecosystems. In northwest North America, the remotely sensed normalized difference vegetation index (NDVI), suggests an increase in productivity of the Arctic and alpine tundra and a decrease in productivity of boreal forests. However, the responses of contrasting shrub species growing at the same sites to climate drivers remain largely unexplored. Here, we test growth, climate, and NDVI relationships of two contrasting species: the expanding tall deciduous shrub Salix pulchra and the circumarctic evergreen dwarf shrub Cassiope tetragona from an alpine tundra site in the Pika valley in the Kluane Region, southwest Yukon Territories, Canada. We found that annual growth variability of both species at this site is strongly driven by early summer temperatures, despite their contrasting traits and habitats. Shrub growth chronologies for both species were correlated with the regional climate signal and showed spatial correspondence with interannual variation in NDVI in surrounding alpine and Arctic regions. Our results suggest that early summer warming represents a common driver of vegetation change for contrasting shrub species growing in different habitats in the same alpine environments.

Growth hormone and early treatment.

PubMed

Antoniazzi, F; Cavarzere, P; Gaudino, R

2015-06-01

Growth hormone (GH) treatment is approved by the US Food and Drug Administration (FDA) not only for GH deficiency (GHD) but also for other childhood growth disorders with growth failure and/or short stature. GHD is the most frequent endocrine disorder presenting with short stature in childhood. During neonatal period, metabolic effects due to congenital GHD require a prompt replacement therapy to avoid possible life-threatening complications. In childhood and adolescence, growth impairment is the most evident effect of GHD and early treatment has the aim of restore normal growth and to reach normal adult height. We reassume in this review the conditions causing GHD and the diagnostic challenge to reach an early diagnosis, and an early treatment, necessary to obtain the best results. Finally, we summarize results obtained in clinical studies about pediatric patients with GHD treated at an early age, in which a marked early catch-up growth and a normalization of adult height were obtained.

The Long-Term Relationship between Population Growth and Vegetation Cover: An Empirical Analysis Based on the Panel Data of 21 Cities in Guangdong Province, China

PubMed Central

Li, Chao; Kuang, Yaoqiu; Huang, Ningsheng; Zhang, Chao

2013-01-01

It is generally believed that there is an inverse relationship between population growth and vegetation cover. However, reports about vegetation protection and reforestation around the World have been continuously increasing in recent decades, which seems to indicate that this relationship may not be true. In this paper, we have taken 21 cities in Guangdong Province, China as the study area to test the long-term relationship between population growth and vegetation cover, using an AVHRR NDVI data set and the panel cointegrated regression method. The results show that there is a long-term inverted N-shaped curve relationship between population growth and vegetation cover in the region where there are frequent human activities and the influence of climate change on vegetation cover changes is relatively small. The two turning points of the inverted N-shaped curve for the case of Guangdong Province correspond to 2,200 persons·km−2 and 3,820 persons·km−2, and they can provide a reference range for similar regions of the World. It also states that the population urbanization may have a negative impact on the vegetation cover at the early stage, but have a positive impact at the later stage. In addition, the Panel Error Correction Model (PECM) is used to investigate the causality direction between population growth and vegetation cover. The results show that not only will the consuming destruction effect and planting construction effect induced by the population growth have a great impact on vegetation cover changes, but vegetation cover changes in turn will also affect the population growth in the long term. PMID:23435589

An improved SWAT vegetation growth module and its evaluation for four tropical ecosystems

NASA Astrophysics Data System (ADS)

Alemayehu, Tadesse; van Griensven, Ann; Taddesse Woldegiorgis, Befekadu; Bauwens, Willy

2017-09-01

The Soil and Water Assessment Tool (SWAT) is a globally applied river basin ecohydrological model used in a wide spectrum of studies, ranging from land use change and climate change impacts studies to research for the development of the best water management practices. However, SWAT has limitations in simulating the seasonal growth cycles for trees and perennial vegetation in the tropics, where rainfall rather than temperature is the dominant plant growth controlling factor. Our goal is to improve the vegetation growth module of SWAT for simulating the vegetation variables - such as the leaf area index (LAI) - for tropical ecosystems. Therefore, we present a modified SWAT version for the tropics (SWAT-T) that uses a straightforward but robust soil moisture index (SMI) - a quotient of rainfall (P) and reference evapotranspiration (ETr) - to dynamically initiate a new growth cycle within a predefined period. Our results for the Mara Basin (Kenya/Tanzania) show that the SWAT-T-simulated LAI corresponds well with the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI for evergreen forest, savanna grassland and shrubland. This indicates that the SMI is reliable for triggering a new annual growth cycle. The water balance components (evapotranspiration and streamflow) simulated by the SWAT-T exhibit a good agreement with remote-sensing-based evapotranspiration (ET-RS) and observed streamflow. The SWAT-T model, with the proposed vegetation growth module for tropical ecosystems, can be a robust tool for simulating the vegetation growth dynamics in hydrologic models in tropical regions.

Integrated Analysis of Climate, Soil, Topography and Vegetative Growth in Iberian Viticultural Regions

PubMed Central

Fraga, Helder; Malheiro, Aureliano C.; Moutinho-Pereira, José; Cardoso, Rita M.; Soares, Pedro M. M.; Cancela, Javier J.; Pinto, Joaquim G.; Santos, João A.

2014-01-01

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate. PMID:25251495

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions.

PubMed

Fraga, Helder; Malheiro, Aureliano C; Moutinho-Pereira, José; Cardoso, Rita M; Soares, Pedro M M; Cancela, Javier J; Pinto, Joaquim G; Santos, João A

2014-01-01

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

Multi-Frequency Investigation into Scattering from Vegetation over the Growth Cycle

NASA Technical Reports Server (NTRS)

Lang, R. H.; Kurum, M.; O'Neill, P. E.; Joseph, A. T.; Deshpande, M. D.; Cosh, M. H.

2016-01-01

In this investigation, we aim to collect and use time-series multi-frequency microwave data over winter wheat during entire growth cycle to characterize vegetation dynamics and to quantify its effects on soil moisture retrievals. We plan to incorporate C-band radar and VHF receiver within the existing L-band radarradiometer system called ComRAD (SMAPs ground based simulator). With C-bands ability to sense vegetation details and VHFs root-zone soil moisture within ComRADs footprint, we will be able to test our discrete scatterer vegetation models and parameters at various surface conditions. The purpose of this study is to determine optical depth and effective scattering albedo of vegetation of a given type (i.e. winter wheat) at various stages of growth that are need to refine soil moisture retrieval algorithms being developed for the SMAP mission.

Seasonal Differences in Climatic Controls of Vegetation Growth in the Beijing-Tianjin Sand Source Region of China.

NASA Astrophysics Data System (ADS)

Wang, H.

2017-12-01

Seasonal differences in climatic controls of vegetation growth in the Beijing-Tianjin Sand Source Region of China Bin He1 , Haiyan Wan11 State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China Corresponding author: Bin He, email addresses: hebin@bnu.edu.cnPhone:+861058806506, Address: Beijing Normal University, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China. Email addresses of co-authors: wanghaiyan@mail.bnu.edu.cnABSTRACTLaunched in 2000, the Beiing-Tainjin Sand Source Controlling Project (BTSSCP) is an ecological restoration project intended to prevent desertification in China. Evidence from multiple sources has confirmed increases in vegetation growth in the BTSSCP region since the initiation of the project. Precipitation and related soil moisture conditions typically are considered to be the main drivers of vegetation growth in this arid region. However, by investigating the relationships between vegetation growth and corresponding climatic factors, we identified seasonal variation in the climatic constraints of vegetation growth. In spring, vegetation growth is stimulated mainly by elevated temperature, whereas precipitation is the lead driver of summer greening. In autumn, positive effects of both temperature and precipitation on vegetation growth were observed. Furthermore, strong biosphere-atmosphere interactions were observed in this region. Spring warming promotes vegetation growth, but also reduces soil moisture. Summer greening has a strong cooling effect on land surface temperature. These results indicate that 1) precipitation-based projections of vegetation growth may be misleading; and 2) the ecological and environment consequences of ecological projects should be comprehensively evaluated. KEYWORDS: vegetation growth, climatic drivers, seasonal variation, BTSSCP

Global latitudinal-asymmetric vegetation growth trends and their driving mechanisms: 1982-2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, Jiafu; Shi, Xiaoying; Thornton, Peter E

2013-01-01

Using a recent Leaf Area Index (LAI) dataset and the Community Land Model version 4 (CLM4), we investigate percent changes and controlling factors of global vegetation growth for the period 1982 to 2009. Over that 28-year period, both the remote-sensing estimate and model simulation show a significant increasing trend in annual vegetation growth. Latitudinal asymmetry appeared in both products, with small increases in the Southern Hemisphere (SH) and larger increases at high latitudes in the Northern Hemisphere (NH). The south-to-north asymmetric land surface warming was assessed to be the principal driver of this latitudinal asymmetry of LAI trend. Heterogeneous precipitationmore » functioned to decrease this latitudinal LAI gradient, and considerably regulated the local LAI change. CO2 fertilization during the last three decades, was simulated to be the dominant cause for the enhanced vegetation growth. Our study, though limited by observational and modeling uncertainties, adds further insight into vegetation growth trends and environmental correlations. These validation exercises also provide new quantitative and objective metrics for evaluation of land ecosystem process models at multiple spatio-temporal scales.« less

Response of alpine vegetation growth dynamics to snow cover phenology on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, X.; Wu, C.

2017-12-01

Alpine vegetation plays a crucial role in global energy cycles with snow cover, an essential component of alpine land cover showing high sensitivity to climate change. The Tibetan Plateau (TP) has a typical alpine vegetation ecosystem and is rich of snow resources. With global warming, the snow of the TP has undergone significant changes that will inevitably affect the growth of alpine vegetation, but observed evidence of such interaction is limited. In particular, a comprehensive understanding of the responses of alpine vegetation growth to snow cover variability is still not well characterized on TP region. To investigate this, we calculated three indicators, the start (SOS) and length (LOS) of growing season, and the maximum of normalized difference vegetation index (NDVImax) as proxies of vegetation growth dynamics from the Moderate Resolution Imaging Spectroradiometer (MODIS) data for 2000-2015. Snow cover duration (SCD) and melt (SCM) dates were also extracted during the same time frame from the combination of MODIS and the Interactive Multi-sensor Snow and Ice Mapping System (IMS) data. We found that the snow cover phenology had a strong control on alpine vegetation growth dynamics. Furthermore, the responses of SOS, LOS and NDVImax to snow cover phenology varied among plant functional types, eco-geographical zones, and temperature and precipitation gradients. The alpine steppes showed a much stronger negative correlation between SOS and SCD, and also a more evidently positive relationship between LOS and SCD than other types, indicating a longer SCD would lead to an earlier SOS and longer LOS. Most areas showed positive correlation between SOS and SCM, while a contrary response was also found in the warm but drier areas. Both SCD and SCM showed positive correlations with NDVImax, but the relationship became weaker with the increase of precipitation. Our findings provided strong evidences between vegetation growth and snow cover phenology, and changes in

Satellite Soil Moisture and Water Storage Observations Identify Early and Late Season Water Supply Influencing Plant Growth in the Missouri Watershed

NASA Astrophysics Data System (ADS)

A, G.; Velicogna, I.; Kimball, J. S.; Du, J.; Kim, Y.; Colliander, A.; Njoku, E. G.

2017-12-01

We employ an array of continuously overlapping global satellite sensor observations including combined surface soil moisture (SM) estimates from SMAP, AMSR-E and AMSR-2, GRACE terrestrial water storage (TWS), and satellite precipitation measurements, to characterize seasonal timing and inter-annual variations of the regional water supply pattern and its associated influence on vegetation growth estimates from MODIS enhanced vegetation index (EVI), AMSR-E/2 vegetation optical depth (VOD) and GOME-2 solar-induced florescence (SIF). Satellite SM is used as a proxy of plant-available water supply sensitive to relatively rapid changes in surface condition, GRACE TWS measures seasonal and inter-annual variations in regional water storage, while precipitation measurements represent the direct water input to the analyzed ecosystem. In the Missouri watershed, we find surface SM variations are the dominant factor controlling vegetation growth following the peak of the growing season. Water supply to growth responds to both direct precipitation inputs and groundwater storage carry-over from prior seasons (winter and spring), depending on land cover distribution and regional climatic condition. For the natural grassland in the more arid central and northwest watershed areas, an early season anomaly in precipitation or surface temperature can have a lagged impact on summer vegetation growth by affecting the surface SM and the underlying TWS supplies. For the croplands in the more humid eastern portions of the watershed, the correspondence between surface SM and plant growth weakens. The combination of these complementary remote-sensing observations provides an effective means for evaluating regional variations in the timing and availability of water supply influencing vegetation growth.

Food for early succession birds: relationships among arthropods, shrub vegetation, and soil

Treesearch

Richard N. Conner; Daniel Saenz; D. Brent Burt

2006-01-01

During spring and early summer, shrub- and herbaceous-level vegetation provides nesting and foraging habitat for many shrub-habitat birds. We examined relationships among arthropod biomass and abundance, foliage leaf surface area and weight, vegetation ground cover, soil characteristics, relative humidity, and temperature to evaluate what factors may influence...

Mid-childhood fruit and vegetable consumption: The roles of early liking, early consumption, and maternal consumption.

PubMed

Kong, Kai Ling; Gillman, Matthew W; Rifas-Shiman, Sheryl L; Wen, Xiaozhong

2016-10-01

Previous studies have shown that early liking, early consumption, and maternal consumption of fruits and vegetables (F&V) each predict children's F&V consumption, but no one has examined the independent contributions of these three correlated factors. We aim to examine the extent to which each of these 3 factors is associated with F&V consumption in mid-childhood after accounting for the other 2 in the analysis. We analyzed data from 901 mother-child dyads from Project Viva, a prospective pre-birth cohort study. Mothers reported their child's early liking and consumption of F&V at age 2 years and later consumption at mid-childhood (median age 7.7 years). They also reported their own consumption of F&V at 6 months postpartum. We used multivariable linear regression models to examine the independent associations of these 3 factors with mid-childhood consumption, adjusting for socio-demographic, pregnancy, and child confounders. At 2 years, 53% of the mothers strongly agreed that their child liked fruit and 25% strongly agreed that their child liked vegetables. F&V consumption was 2.5 (1.3) and 1.8 (1.1) times/d at age 2 y and 1.5 (1.1) and 1.3 (0.8) times/d in mid-childhood. Maternal F&V consumption was 1.4 (1.1) and 1.5 (1.0) times/d, respectively. Children's early consumption played the most predominant role. For every 1 time/d increment in children's early consumption of F&V, mid-childhood consumption was higher by 0.25 (95% confidence interval [CI]: 0.19, 0.30) times/d for fruits and 0.21 (95% CI: 0.16, 0.26) times/d for vegetables, adjusted for confounders plus the other 2 exposures. In conclusion, children's early F&V consumption has the most significant influence on children's later consumption. Published by Elsevier Ltd.

Monitoring the growth or decline of vegetation on mine dumps

NASA Technical Reports Server (NTRS)

Gilbertson, B. P. (Principal Investigator)

1975-01-01

The author has identified the following signficant results. It was established that particular mine dumps throughout the entire test area can be detected and identified. It was also established that patterns of vegetative growth on the mine dumps can be recognized from a simple visual analysis of photographic images. Because vegetation tends to occur in patches on many mine dumps, it is unsatisfactory to classify complete dumps into categories of percentage vegetative cover. A more desirable approach is to classify the patches of vegetation themselves. The coarse resolution of conventional densitometers restricts the accuracy of this procedure, and consequently a direct analysis of ERTS CCT's is preferred. A set of computer programs was written to perform the data reading and manipulating functions required for basic CCT analysis.

Detection and attribution of vegetation growth change in China during the last thirty years

NASA Astrophysics Data System (ADS)

Tan, J.; Wang, X.; Mao, J.; Shi, X.; Peng, S.; Zeng, Z.; Piao, S.

2013-12-01

Enhanced terrestrial vegetation growth in China over the past three decades has been proved by satellite observations. During the same period, China has experienced dramatic land use and land cover changes. Those changes can not only strengthen the vegetation growth by afforestation and agricultural management, but also weaken it by urbanization and overgrazing. Compared to global climate changes, the effect of land use and land cover changes (LULCC) in China vegetation growth is still not clear. A further understanding of the mechanisms for this phenomenon is crucial for projecting future ecosystem dynamics. To investigate the variation of vegetation growth in Chinese provinces and evaluate its responses to external driving factors from 1982 to 2009, two mechanistic terrestrial carbon models (CLM and OCHIDEE) have been applied in this paper. The modeled Leaf Area Index (LAI) from the two models has been increasing, which is consistent to the satellite LAI. On that basis, a series of factorial simulations based on the two models were processed to separate independent contributions of external driving factors to LAI. Besides of climate changing and LULCC, other external driving factors were also considered such as CO2 and nitrogen deposition. The results indicate that the distribution of LAI trend is far from homogeneous at provincial scale and highest LAI trend happened in South China. The dominant influential factor varies in different provinces. Climate-only simulation may not explain the vegetation growth change well in all the provinces. CO2 and LULCC seem to play a more important role in South China which matches the region with sharp increase of LAI. This phenomenon shows that the anthropology-oriented impact cannot be ignored under the background of global climate change and it is vital for further exploration of the effect of human society to vegetation growth.

Complex Genetic Effects on Early Vegetative Development Shape Resource Allocation Differences Between Arabidopsis lyrata Populations

PubMed Central

Remington, David L.; Leinonen, Päivi H.; Leppälä, Johanna; Savolainen, Outi

2013-01-01

Costs of reproduction due to resource allocation trade-offs have long been recognized as key forces in life history evolution, but little is known about their functional or genetic basis. Arabidopsis lyrata, a perennial relative of the annual model plant A. thaliana with a wide climatic distribution, has populations that are strongly diverged in resource allocation. In this study, we evaluated the genetic and functional basis for variation in resource allocation in a reciprocal transplant experiment, using four A. lyrata populations and F2 progeny from a cross between North Carolina (NC) and Norway parents, which had the most divergent resource allocation patterns. Local alleles at quantitative trait loci (QTL) at a North Carolina field site increased reproductive output while reducing vegetative growth. These QTL had little overlap with flowering date QTL. Structural equation models incorporating QTL genotypes and traits indicated that resource allocation differences result primarily from QTL effects on early vegetative growth patterns, with cascading effects on later vegetative and reproductive development. At a Norway field site, North Carolina alleles at some of the same QTL regions reduced survival and reproductive output components, but these effects were not associated with resource allocation trade-offs in the Norway environment. Our results indicate that resource allocation in perennial plants may involve important adaptive mechanisms largely independent of flowering time. Moreover, the contributions of resource allocation QTL to local adaptation appear to result from their effects on developmental timing and its interaction with environmental constraints, and not from simple models of reproductive costs. PMID:23979581

Survival and growth of foodborne pathogens in minimally processed vegetables at 4 and 15 °C.

PubMed

Tian, Jun-Qi; Bae, Young-Min; Choi, Na-Young; Kang, Dong-Hyun; Heu, Sunggi; Lee, Sun-Young

2012-01-01

We conducted this study to investigate the survival and growth of pathogens on fresh vegetables stored at 4 and 15 °C. Vegetables (romaine lettuce, iceberg lettuce, perilla leaves, and sprouts) were inoculated with 4 pathogens (Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157:H7) and stored at 2 different temperatures for different periods of time (3, 6, 9, 12, and 15 d at 4 °C and 1, 2, 3, 5, and 7 d at 15 °C). Populations of the 4 pathogens tended to increase on all vegetables stored at 15 °C for 7 d. Populations of E. coli O157:H7 and S. Typhimurium increased significantly, by approximately 2 log₁₀ CFU/g, on loose and head lettuce stored at 15 °C for 1 d. No significant differences were observed in the growth of different pathogens on vegetables stored at 4 °C for 15 d. E. coli O157:H7 did not survive on sprouts stored at 15 or 4 °C. The survival and growth of food pathogens on fresh vegetables were very different depending on the pathogen type and storage temperature. Survivals and growth of pathogens on various vegetables at 4 and 15 °C were observed in this study. Survivals and growth of pathogens on vegetables were different depending on the pathogen type and storage temperature. Therefore, vegetables should be stored under refrigerated conditions (below 4 °C) prior to consumption. This recommendation may vary depending on the type of vegetable. © 2011 Institute of Food Technologists®

Effects of industrial wastewater on growth and biomass production in commonly grown vegetables.

PubMed

Uzma, Syeda; Azizullah, Azizullah; Bibi, Roqaia; Nabeela, Farhat; Muhammad, Uzair; Ali, Imran; Rehman, Zia Ur; Häder, Donat-Peter

2016-06-01

In developing countries like Pakistan, irrigation of crops with industrial and municipal wastewater is a common practice. However, the impact of wastewater irrigation on vegetables growth has rarely been studied. Therefore, the present study was conducted to determine the effect of industrial wastewater on the germination and seedling growth of some commonly grown vegetables in Pakistan. Wastewater samples were collected from two different industries (marble industry and match alam factory) at Hayatabad Industrial Estate (HIE) in Peshawar, Pakistan, and their effect on different growth parameters of four vegetables including Hibiscus esculentus, Lactuca sativa, Cucumis sativus, and Cucumis melo was investigated. The obtained results revealed that wastewater from marble industry did not affect seed germination except a minor inhibition in H. esculentus. Effluents from match alam factory stimulated seed germination in C. melo and C. sativus but had no effect on seed germination in the other two vegetables. Wastewater increased root and shoot length in H. esculentus, L. sativa and C. melo, but decreased it in C. sativus. Similarly, differential effects of wastewater were observed on fresh and dry biomass of seedlings in all vegetables. It can be concluded that wastewater may have different effects on different crops, depending upon the nature of wastewater and sensitivity of a plant species to wastewater.

On the botanic model of plant growth with intermediate vegetative-reproductive stage.

PubMed

Ioslovich, Ilya; Gutman, Per-Olof

2005-11-01

The application of dynamic optimization to mathematical models of ontogenic biological growth has been the subject of much research [see e.g. . J. Theor. Biol. 33, 299-307]. Kozłowsky and Ziółko [1988. Thor. Popul. Biol. 34, 118-129] and Ziółko and Kozłowski [1995. IEEE Trans. Automat. Contr. 40(10), 1779-1783] presented a model with gradual transition from vegetative to reproductive growth. The central point of their model is a mixed state-control constraint on the rate of reproductive growth, which leads to a mixed vegetative-reproductive growth period. Their model is modified here in order to take into account the difference of photosynthesis use efficiency when energy is accumulated in the vegetative and in the reproductive organs of a plant, respectively. The simple assumption on correlation between photosynthesis and temperature permits us to modify the model in a form that is useful for changing climate. Unfortunately, the mathematical solution of the optimal control problem in Kozłowsky and Ziółko (1988) and Ziółko and Kozłowski (1995) is incorrect. The strict mathematical solution is presented here, the numerical example from is solved, and the results are compared. The influence of the length of the season and the relative photosynthesis use efficiency, as well as of the potential sink demand of the reproductive organs, on the location and duration of the mixed vegetative-reproduction period of growth is investigated numerically. The results show that the mixed growth period is increased and shifted toward the end of the season when the lengths of the season is increased. Additional details of the sensitivity analysis are also presented.

Morphogenesis at the inflorescence shoot apex of Anagallis arvensis: surface geometry and growth in comparison with the vegetative shoot.

PubMed

Kwiatkowska, Dorota; Routier-Kierzkowska, Anne-Lise

2009-01-01

Quantitative analysis of geometry and surface growth based on the sequential replica method is used to compare morphogenesis at the shoot apex of Anagallis arvensis in the reproductive and vegetative phases of development. Formation of three types of lateral organs takes place at the Anagallis shoot apical meristem (SAM): vegetative leaf primordia are formed during the vegetative phase and leaf-like bracts and flower primordia during the reproductive phase. Although the shapes of all the three types of primordia are very similar during their early developmental stages, areal growth rates and anisotropy of apex surface growth accompanying formation of leaf or bract primordia are profoundly different from those during formation of flower primordia. This provides an example of different modes of de novo formation of a given shape. Moreover, growth accompanying the formation of the boundary between the SAM and flower primordium is entirely different from growth at the adaxial leaf or bract primordium boundary. In the latter, areal growth rates at the future boundary are the lowest of all the apex surface, while in the former they are relatively very high. The direction of maximal growth rate is latitudinal (along the future boundary) in the case of leaf or bract primordium but meridional (across the boundary) in the case of flower. The replica method does not enable direct analysis of growth in the direction perpendicular to the apex surface (anticlinal direction). Nevertheless, the reconstructed surfaces of consecutive replicas taken from an individual apex allow general directions of SAM surface bulging accompanying primordium formation to be recognized. Precise alignment of consecutive reconstructions shows that the direction of initial bulging during the leaf or bract formation is nearly parallel to the shoot axis (upward bulging), while in the case of flower it is perpendicular to the axis (lateral bulging). In future, such 3D reconstructions can be used to assess

Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

PubMed

Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

2015-09-01

Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

The method for detecting biological parameter of rice growth and early planting of paddy crop by using multi temporal remote sensing data

NASA Astrophysics Data System (ADS)

Domiri, D. D.

2017-01-01

Rice crop is the most important food crop for the Asian population, especially in Indonesia. During the growth of rice plants have four main phases, namely the early planting or inundation phase, the vegetative phase, the generative phase, and bare land phase. Monitoring the condition of the rice plant needs to be conducted in order to know whether the rice plants have problems or not in its growth. Application of remote sensing technology, which uses satellite data such as Landsat 8 and others which has a spatial and temporal resolution is high enough for monitoring the condition of crops such as paddy crop in a large area. In this study has been made an algorithm for monitoring rapidly of rice growth condition using Maximum of Vegetation Index (EVI Max). The results showed that the time of early planting can be estimated if known when EVI Max occurred. The value of EVI Max and when it occured can be known by trough spatial analysis of multitemporal EVI Landsat 8 or other medium spatial resolution satellites.

Hpa1 harpin needs nitroxyl terminus to promote vegetative growth and leaf photosynthesis in Arabidopsis.

PubMed

Li, Xiaojie; Han, Liping; Zhao, Yanying; You, Zhenzhen; Dong, Hansong; Zhang, Chunling

2014-03-01

Hpa1 is a harpin protein produced by Xanthomonas oryzae, an important bacterial pathogen of rice, and has the growth-promoting activity in plants. To understand the molecular basis for the function of Hpa1, we generated an inactive variant protein, Hpa1 delta NT, by deleting the nitroxyl-terminal region of the Hpa1 sequence and compared Hpa1 delta NT with the full-length protein in terms of the effects on vegetative growth and related physiological responses in Arabidopsis. When Hpa1 was applied to plants, it acted to enhance the vegetative growth but did not affect the floral development. Enhanced plant growth was accompanied by induced expression of growth-promoting genes in plant leaves. The growth-promoting activity of Hpa1 was further correlated with a physiological consequence shown as promoted leaf photosynthesis as a result of facilitated CO2 conduction through leaf stomata and mesophyll cells. On the contrary, plant growth, growth-promoting gene expression, and the physiological consequence changed little in response to the Hpa1 delta NT treatment. These analyses suggest that Hpa1 requires the nitroxyl-terminus to facilitate CO2 transport inside leaf cells and promote leaf photosynthesis and vegetative growth of the plant.

Early recognition of growth abnormalities permitting early intervention

USDA-ARS?s Scientific Manuscript database

Normal growth is a sign of good health. Monitoring for growth disturbances is fundamental to children's health care. Early detection and diagnosis of the causes of short stature allows management of underlying medical conditions, optimizing attainment of good health and normal adult height. This rev...

Tree growth and vegetation activity at the ecosystem-scale in the eastern Mediterranean

NASA Astrophysics Data System (ADS)

Coulthard, Bethany L.; Touchan, Ramzi; Anchukaitis, Kevin J.; Meko, David M.; Sivrikaya, Fatih

2017-08-01

Linking annual tree growth with remotely-sensed terrestrial vegetation indices provides a basis for using tree rings as proxies for ecosystem primary productivity over large spatial and long temporal scales. In contrast with most previous tree ring/remote sensing studies that have focused on temperature-limited boreal and taiga environments, here we compare the normalized difference vegetation index (NDVI) with a network of Pinus brutia tree ring width chronologies collected along ecological gradients in semiarid Cyprus, where both radial tree growth and broader vegetation activity are controlled by drought. We find that the interaction between precipitation, elevation, and land-cover type generate a relationship between radial tree growth and NDVI. While tree ring chronologies at higher-elevation forested sites do not exhibit climate-driven linkages with NDVI, chronologies at lower-elevation dry sites are strongly correlated with NDVI during the winter precipitation season. At lower-elevation sites, land cover is dominated by grasslands and shrublands and tree ring widths operate as a proxy for ecosystem-scale vegetation activity. Tree rings can therefore be used to reconstruct productivity in water-limited grasslands and shrublands, where future drought stress is expected to alter the global carbon cycle, biodiversity, and ecosystem functioning in the 21st century.

Effects of site preparation treatments on early growth and survival of planted longleaf pine (Pinus palustris Mill.) seedlings in North Carolina

Treesearch

Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker; Susan Cohen

2006-01-01

We tested the effects of eight site preparation treatments on early growth and survival of container-grown longleaf pine (Pinus palustris Mill.) seedlings. Treatments included an untreated check, six combinations of two initial vegetation control treatments (chopping or herbicide) with three planting site conditions (flat [no additional treatment],...

Exploring the contributions of vegetation and dune size to early dune development using unmanned aerial vehicle (UAV) imaging

NASA Astrophysics Data System (ADS)

van Puijenbroek, Marinka E. B.; Nolet, Corjan; de Groot, Alma V.; Suomalainen, Juha M.; Riksen, Michel J. P. M.; Berendse, Frank; Limpens, Juul

2017-12-01

Dune development along highly dynamic land-sea boundaries is the result of interaction between vegetation and dune size with sedimentation and erosion processes. Disentangling the contribution of vegetation characteristics from that of dune size would improve predictions of nebkha dune development under a changing climate, but has proven difficult due to the scarcity of spatially continuous monitoring data. This study explored the contributions of vegetation and dune size to dune development for locations differing in shelter from the sea. We monitored a natural nebkha dune field of 8 ha, along the coast of the island Texel, the Netherlands, for 1 year using an unmanned aerial vehicle (UAV) with camera. After constructing a digital surface model and orthomosaic we derived for each dune (1) vegetation characteristics (species composition, vegetation density, and maximum vegetation height), (2) dune size (dune volume, area, and maximum height), (3) degree of shelter (proximity to other nebkha dunes and the sheltering by the foredune). Changes in dune volume over summer and winter were related to vegetation, dune size and degree of shelter. We found that a positive change in dune volume (dune growth) was linearly related to initial dune volume over summer but not over winter. Big dunes accumulated more sand than small dunes due to their larger surface area. Exposed dunes increased more in volume (0.81 % per dune per week) than sheltered dunes (0.2 % per dune per week) over summer, while the opposite occurred over winter. Vegetation characteristics did not significantly affect dune growth in summer, but did significantly affect dune growth in winter. Over winter, dunes dominated by Ammophila arenaria, a grass species with high vegetation density throughout the year, increased more in volume than dunes dominated by Elytrigia juncea, a grass species with lower vegetation density (0.43 vs. 0.42 (m3 m-3) week-1). The effect of species was irrespective of dune size or

Monitoring and diagnosis of vegetable growth based on internet of things

NASA Astrophysics Data System (ADS)

Zhang, Qian; Yu, Feng; Fu, Rong; Li, Gang

2017-10-01

A new condition monitoring method of vegetable growth was proposed, which was based on internet of things. It was combined remote environmental monitoring, video surveillance, intelligently decision-making and two-way video consultation together organically.

Survival, growth, and body residues of hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms.

PubMed

Kröger, Robert; Lizotte, Richard E; Moore, Matthew T

2009-09-01

We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g(-1)) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g(-1)) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.

Plant characteristics and growth parameters of vegetable pigeon pea cultivars

USDA-ARS?s Scientific Manuscript database

Pigeon pea is an important crop in dry land and semi-arid regions and is a supplementary source of dietary protein for the resource-constrained farmers. The aim of this research was to evaluate growth parameters of twelve vegetable pigeon pea genotypes at two locations in Eastern Kenya. The number o...

Urban vegetation and thermal patterns following city growth in different socio-economic contexts

NASA Astrophysics Data System (ADS)

Dronova, I.; Clinton, N.; Yang, J.; Radke, J.; Marx, S. S.; Gong, P.

2015-12-01

Urban expansion accompanied by losses of vegetated spaces and their ecological services raises significant concerns about the future of humans in metropolitan "habitats". Despite recent growth of urban studies globally, it is still not well understood how environmental effects of urbanization vary with the rate and socioeconomic context of development. Our study hypothesized that with urban development, spatial patterns of surface thermal properties and green plant cover would shift towards higher occurrence of relatively warmer and less vegetated spaces such as built-up areas, followed by losses of greener and cooler areas such as urban forests, and that these shifts would be more pronounced with higher rate of economic and/or population growth. To test these ideas, we compared 1992-2011 changes in remotely sensed patterns of green vegetation and surface temperature in three example cities that experienced peripheral growth under contrasting socio-economic context - Dallas, TX, USA, Beijing, China and Kyiv, Ukraine. To assess their transformation, we proposed a metric of thermal-vegetation angle (TVA) estimated from per-pixel proxies of vegetation greenness and surface temperature from Landsat satellite data and examined changes in TVA distributions within each city's core and two decadal zones of peripheral sprawl delineated from nighttime satellite data. We found that higher economic and population growth were coupled with more pronounced changes in TVA distributions, and more urbanized zones often exhibited higher frequencies of warmer, less green than average TVA values with novel patterns such as "cooler" clusters of building shadows. Although greener and cooler spaces generally diminished with development, they remained relatively prevalent in low-density residential areas of Dallas and peripheral zones of Kyiv with exurban subsistence farming. Overall, results indicate that the effects of modified green space and thermal patterns within growing cities

Effect of Spent Mushroom Compost of Pleurotus pulmonarius on Growth Performance of Four Nigerian Vegetables

PubMed Central

Lawal, Muritala Mobolaji; Oyetunji, Olusola Jacob

2011-01-01

Spent mushroom compost (SMC) of Pleurotus pulmonarius (an edible fungus) was used as soil conditioner for the improvement of growth of four common Nigerian vegetables (Abelmoschus esculentus, Lycopersicum esculentum, Capsicum annum and Capsicum chinense). The results of these investigations showed that the vegetables responded well to the SMC treatment. Each of them attained its best growth and gave the highest number of flowers and fruits when planted on 6 kg of depleted garden soil supplemented with 600 g of SMC. The control experiment that has the seedlings of the vegetables planted on 6 kg of depleted garden soil only, without the application of SMC, showed stunted and poor growth, with few or no flower and fruit production. A. esculentus was the best utilizer of iron utilizing 118.0 mg/kg in the SMC used. Similarly; this vegetable utilized 1.48 mg/kg of nitrogen in the SMC. The highest height in each vegetable was attained with 6 kg of depleted garden soil supplemented with 600 g of SMC. At 9 wk, A. esculentus has the mean height of 85.0 cm while these values significantly increased to 100.00 cm at 14 wk (p ≤ 0.05). At 9 wk, L. esculentum has the highest mean height of 65.00 cm which increased to 71.00 cm after 14 wk. It was also observed that A. esculentus has the highest mean number of fruits (9.00), followed in order by C. chinense (8.00) and L. esculentus (7.00) (p ≤ 0.05) while, C. annum produced the least mean number of fruits (5.00). No fruits production was seen in the control experiments. The results of these findings were discussed in relation to the usage of SMC as possible organic fertilizer for the improvement of growth of vegetables in Nigeria. PMID:22783098

Effect of traditional leafy vegetables on the growth of lactobacilli and bifidobacteria.

PubMed

Kassim, Muhammad Arshad; Baijnath, Himansu; Odhav, Bharti

2014-12-01

Traditional leafy vegetables, apart from being a staple in the diet of most of sub-Saharan Africa, are an essential part of traditional medicine and are used daily by traditional healers in the region to treat a wide variety of ailments. In this study, a batch culture technique was used to investigate whether 25 infusions from 22 traditional leafy vegetables stimulated the growth of Lactobacillus bulgaricus, Lactobacillus lactis, Lactobacillus reuteri and Bifidobacterium longum in pure culture. High performance liquid chromatography was used to determine the inulin content of the infusions. Sonchus oleraceus stimulated all four strains and Taraxacum officinale stimulated three strains. In total, 18 plants stimulated at least one of the four probiotic strains. The inulin content of the infusions varied between 2.5% and 3.6%, with Asparagus sprengeri containing the highest percentage. These results indicate that traditional leafy vegetables do stimulate the growth of the selected lactobacilli and bifidobacteria in pure culture and contain inulin. These infusions can now be tested for prebiotic potential using mixed culture systems or human hosts.

Plio-Pleistocene vegetation response on orbitally forced climatic cycles in Southern Europe - implications for early human environments

NASA Astrophysics Data System (ADS)

Bruch, Angela; Bertini, Adele

2013-04-01

The pace and causes of the early human colonization, in one or several migratory waves from Africa in new environments of the Eurasian continent during the Early Pleistocene, are still a matter of debate. However, climate change is considered a major driving factor of hominin evolution and dispersal patterns. In fact directly or indirectly by its severe influence on vegetation, physiography of landscape, and animal distribution, climate modulates the availability of resources. Plant fossils usually are rare or even absent at hominin sites. Thus, direct evidence on local vegetation and environment is generally missing. Independent from such localities, pollen profiles from the Mediterranean realm show the response of regional vegetation on global climate changes and cyclicity, with distinct spatial and temporal differences. Furthermore, plant fossils provide proxies for climate quantification that can be compared to the global signal, and add data to understanding the regional differentiation of Mediterranean environments. In this presentation we will discuss various palaeobotanical data from Southern Europe to assess Early Pleistocene climate and vegetation in time and space as part of the environment during the first expansions of early humans out of Africa.

Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica.

PubMed

Oñate, Marta; Munné-Bosch, Sergi

2009-10-01

Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, alpha-tocopherol and F(v)/F(m) ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of alpha-tocopherol (up to 2.7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants.

Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica

PubMed Central

Oñate, Marta; Munné-Bosch, Sergi

2009-01-01

Background and Aims Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Methods Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, α-tocopherol and Fv/Fm ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Key Results Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of α-tocopherol (up to 2·7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. Conclusions It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants. PMID:19633309

Differentiating drought legacy effects on vegetation growth over the temperate Northern Hemisphere.

PubMed

Wu, Xiuchen; Liu, Hongyan; Li, Xiaoyan; Ciais, Philippe; Babst, Flurin; Guo, Weichao; Zhang, Cicheng; Magliulo, Vincenzo; Pavelka, Marian; Liu, Shaomin; Huang, Yongmei; Wang, Pei; Shi, Chunming; Ma, Yujun

2018-01-01

In view of future changes in climate, it is important to better understand how different plant functional groups (PFGs) respond to warmer and drier conditions, particularly in temperate regions where an increase in both the frequency and severity of drought is expected. The patterns and mechanisms of immediate and delayed impacts of extreme drought on vegetation growth remain poorly quantified. Using satellite measurements of vegetation greenness, in-situ tree-ring records, eddy-covariance CO 2 and water flux measurements, and meta-analyses of source water of plant use among PFGs, we show that drought legacy effects on vegetation growth differ markedly between forests, shrubs and grass across diverse bioclimatic conditions over the temperate Northern Hemisphere. Deep-rooted forests exhibit a drought legacy response with reduced growth during up to 4 years after an extreme drought, whereas shrubs and grass have drought legacy effects of approximately 2 years and 1 year, respectively. Statistical analyses partly attribute the differences in drought legacy effects among PFGs to plant eco-hydrological properties (related to traits), including plant water use and hydraulic responses. These results can be used to improve the representation of drought response of different PFGs in land surface models, and assess their biogeochemical and biophysical feedbacks in response to a warmer and drier climate. © 2017 John Wiley & Sons Ltd.

Changes in fruit and vegetable consumption habits from pre-pregnancy to early pregnancy among Norwegian women.

PubMed

Skreden, Marianne; Bere, Elling; Sagedal, Linda R; Vistad, Ingvild; Øverby, Nina C

2017-04-04

A healthy diet is important for pregnancy outcome and the current and future health of woman and child. The aims of the study were to explore the changes from pre-pregnancy to early pregnancy in consumption of fruits and vegetables (FV), and to describe associations with maternal educational level, body mass index (BMI) and age. Healthy nulliparous women were included in the Norwegian Fit for Delivery (NFFD) trial from September 2009 to February 2013, recruited from eight antenatal clinics in southern Norway. At inclusion, in median gestational week 15 (range 9-20), 575 participants answered a food frequency questionnaire (FFQ) where they reported consumption of FV, both current intake and recollection of pre-pregnancy intake. Data were analysed using a linear mixed model. The percentage of women consuming FV daily or more frequently in the following categories increased from pre-pregnancy to early pregnancy: vegetables on sandwiches (13 vs. 17%, p <0.01), other vegetables (11 vs. 14%, p = 0.01), fruits (apples, pears, oranges or bananas) (24 vs. 41%, p < 0.01), other fruits and berries (8 vs. 15%, p < 0.01) and fruits and vegetables as snacks (14 vs. 28%, p < 0.01). The percentage of women who reported at least daily consumption of vegetables with dinner (22% at both time points) was stable. A higher proportion of older women increased their consumption of vegetables and fruits as snacks from pre-pregnancy to early pregnancy compared to younger women (p=0.04). We found an increase in the proportion of women consuming FV daily or more frequently from pre-pregnancy to early pregnancy. ClinicalTrials.gov database, NCT01001689 . https://clinicaltrials.gov/ct2/show/NCT01001689?term=NCT01001689&rank=1 .

Patterns and drivers of Early Holocene vegetation dynamics in Central Europe

NASA Astrophysics Data System (ADS)

Theuerkauf, Martin

2015-04-01

The rapid warming of the Holocene induced the rearrangement of vegetation across Europe, including the widely synchronous and rapid expansion of hazel (Corylus avellana) at around 10.6 ka BP (Giesecke et al., 2011). The simultaneity of the hazel expansion across large parts of Europe suggests that a climate shift has triggered that expansion. However, it remains poorly understood, which climate parameter has been effective (Huntley, 1993) because hazel expanded simultaneously in areas that today clearly differ in climate. To better understand the causes we studied Early Holocene vegetation dynamics in NE Germany in high temporal and spatial resolution. Analysis combines pollen data from 60 sites, including high resolution data sets, with present-day site patterns of soil and relief using the extended downscaling approach. Using forward modeling of pollen deposition in each sample site the method seeks that vegetation composition on each site type that produces modeled pollen deposition most similar to empiric pollen deposition. The results (Theuerkauf et al., 2014) indicate that first populations of hazel established soon after the Holocene warming at 11.2 ka. These populations were still small and possibly restricted to warm loving slopes, indicating that low summer warmth was the limiting factor. The widespread expansion of hazel started only after 10.8 ka, possibly following a shift to greater summer warmth. Hazel primarily expanded on sites that are today covered by gleyic soils, from which it largely expelled tree birch. Hazel thus obviously could only expand on sites that received additional wetness from ground- and stagnant water. Giesecke T., Bennett K.D., Birks H.J.B., Bjune A.E., Bozilova E., Feurdean A., Finsinger W., Froyd C., Pokorný P., Rösch M., Seppä H., Tonkov S., Valsecchi V., & Wolters S. (2011) The pace of Holocene vegetation change - testing for synchronous developments. Quaternary Science Reviews, 30, 2805-2814. Huntley B. (1993) Rapid

Lateral vegetation growth rates exert control on coastal foredune hummockiness and coalescing time

NASA Astrophysics Data System (ADS)

Goldstein, Evan B.; Moore, Laura J.; Durán Vinent, Orencio

2017-08-01

Coastal foredunes form along sandy, low-sloped coastlines and range in shape from continuous dune ridges to hummocky features, which are characterized by alongshore-variable dune crest elevations. Initially scattered dune-building plants and species that grow slowly in the lateral direction have been implicated as a cause of foredune hummockiness. Our goal in this work is to explore how the initial configuration of vegetation and vegetation growth characteristics control the development of hummocky coastal dunes including the maximum hummockiness of a given dune field. We find that given sufficient time and absent external forcing, hummocky foredunes coalesce to form continuous dune ridges. Model results yield a predictive rule for the timescale of coalescing and the height of the coalesced dune that depends on initial plant dispersal and two parameters that control the lateral and vertical growth of vegetation, respectively. Our findings agree with previous observational and conceptual work - whether or not hummockiness will be maintained depends on the timescale of coalescing relative to the recurrence interval of high-water events that reset dune building in low areas between hummocks. Additionally, our model reproduces the observed tendency for foredunes to be hummocky along the southeast coast of the US where lateral vegetation growth rates are slower and thus coalescing times are likely longer.

Effect of overstorey trees on understorey vegetation in California (USA) ponderosa pine plantations

Treesearch

Jianwei Zhang; David H. Young; William W. Oliver; Gary O. Fiddler

2016-01-01

Understorey vegetation plays a significant role in the structure and function of forest ecosystems. Controlling understorey vegetation has proven to be an effective tool in increasing tree growth and overstorey development. However, a long-term consequence of the practice on plant diversity is not fully understood. Here, we analyzed early development of overstorey and...

Growth of Aeromonas hydrophila on fresh vegetables stored under a controlled atmosphere.

PubMed Central

Berrang, M E; Brackett, R E; Beuchat, L R

1989-01-01

The effects of controlled-atmosphere storage (CAS) on the survival and growth of Aeromonas hydrophila on fresh asparagus, broccoli, and cauliflower were examined. Two lots of each vegetable were inoculated with A. hydrophila 1653 or K144. A third lot served as an uninoculated control. Following inoculation, vegetables were stored at 4 or 15 degrees C under a CAS system previously shown to extend the shelf life of each commodity or under ambient air. Populations of A. hydrophila were enumerated on the initial day of inoculation and at various intervals for 10 days (15 degrees C) or 21 days (4 degrees C) of storage. Direct plating of samples with selective media was used to enumerate A. hydrophila. The organism was detected on most lots of vegetables as they were received from a commercial produce supplier. Without exception, the CAS system lengthened the time vegetables were subjectively considered acceptable for consumption. However, CAS did not significantly affect populations of A. hydrophila which survived or grew on inoculated vegetables. PMID:2802601

Falls, sarcopenia and growth in early life

PubMed Central

Sayer, Avan Aihie; Syddall, Holly E; Martin, Helen J; Dennison, Elaine M; Anderson, Frazer H; Cooper, Cyrus

2007-01-01

Recent studies have shown that people with poor early growth have an increased risk of sarcopenia. Sarcopenia is an important risk factor for falls but it is not known whether poor early growth is related to falls. We investigated this in the Hertfordshire Cohort Study where 2148 participants completed a falls history. Grip strength was used as a marker of sarcopenia. Birth weight, weight at one year and conditional infant growth were analysed in relation to falls history. The prevalence of any fall in the last year was 14.3% for men and 22.5% for women. Falls in the last year were inversely related to adult grip strength, height and walking speed in men and women as well as to lower conditional infant growth in men (OR 1.27 [95% CI 1.04, 1.56] per SD decrease in conditional infant growth, p=0.02). This association was attenuated after adjustment for grip strength. Our findings support an association between poor early growth and falls in older men which appears to be mediated partly through sarcopenia. The lack of relationship with birth weight suggests that postnatal rather than prenatal influences on muscle growth and development may be important for risk of falls in later life. PMID:16905644

Effect of animal sera on Bacillus anthracis Sterne spore germination and vegetative cell growth.

PubMed

Bensman, M D; Mackie, R S; Minter, Z A; Gutting, B W

2012-08-01

 The aims of this work were to investigate the effects of sera on B. anthracis Sterne germination and growth. Sera examined included human, monkey and rabbit sera, as well as sera from eight other species.  Standard dilution plate assay (with and without heat kill) was used as a measure of germination, and spectroscopy was used to measure growth. In addition, a Coulter Counter particle counter was used to monitor germination and growth based on bacterial size. Spores germinated best in foetal bovine and monkey sera, moderately with human sera and showed limited germination in the presence of rabbit or rat sera. Vegetative bacteria grew best in foetal bovine sera and moderately in rabbit sera. Human and monkey sera supported little growth of vegetative bacteria.  The data suggested sera can have a significant impact on germination and growth of Sterne bacteria.  These data should be considered when conducting in vitro cell culture studies and may aid in interpreting in vivo infection studies. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Throughfall Monitoring Of Old Growth, Second Growth, And Cleared Vegetation Plots On Prince of Wales Island, Alaska

NASA Astrophysics Data System (ADS)

Prussian, K. M.

2006-12-01

The density of forest canopy affects the amount of rain reaching the forest floor in forested environments of Southeast Alaska. Less throughfall occurs in the second growth sites than in the old growth site and greater throughfall occurs in the clear-cut sites. More specifically, preliminary data show that SG sites received between 38 and 87% of the OG throughfall and the clear-cut sites experienced between 145 and 248% of the OG throughfall. Precipitation gages were used to monitor throughfall in each of the forested vegetation sites on Prince of Wales Island, Alaska, as an indicator of the amount of water reaching the forest floor in these different forest types. Data collected during 2004 and 2005 included 23 storms ranging from 0.2 to 10.6 inches of rain in the clear-cut forest. This monitoring is an effort to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. Site selection focused on similarities in location, elevation, aspect, and accessibility while accounting for the three varying vegetation conditions. Data collected during 2004 and 2005 sampling seasons were in the same sampling plots, while data collected in 2006 is a duplicate set of sites. Twenty-three storms were used to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. The second growth stand was harvested in 1979 and is currently in stem re-initiation phase with thick conifer regeneration. The clear-cut site was harvested in 1999 and contains conifer vegetation, blueberry, and salmonberry vegetation less than five feet in height. Storms were defined as events that were clearly delineated by lack of rainfall for a period of time, or similar antecedent conditions, and totaled at least .2 inches of rain at the CC site. Analysis of a storm

Clarifying the effects of dwarfing rootstock on vegetative and reproductive growth during tree development: a study on apple trees.

PubMed

Costes, E; García-Villanueva, E

2007-08-01

Despite the widespread use of dwarfing rootstocks in the fruit-tree industry, their impact on tree architectural development and possible role in the within-tree balance between growth and flowering are still poorly understood, in particular during the early years of growth. The present study addressed this question in apple trees, through a detailed analysis of shoot populations, i.e. both vegetative and flowering shoots, during tree development. Architectural databases were constructed for trees of two cultivars that were either own-rooted or grafted on dwarfing rootstock. Within-tree shoot demographics and annual shoot characteristics, i.e. their dimensions, number of laterals and flowering, were observed from the first to the fifth year of growth and compared among scion/root system combinations. Differences in axis demographics appeared among scion/root system combinations after the second year of growth. Differences were found (a) in the number of long axes and (b) the number of medium axes. Dwarfing rootstock reduced the total number of axes developed in a tree, and this reduction resulted from proportionally more medium axes and spurs than long axes. The life span of spurs was also shortened. These phenomena appeared after an increase in flowering that started in the second year of growth and involved both axillary and terminal positions. Flowering regularity was also increased in grafted trees. These results confirm that the number of long shoots and flowering potential depend on the cultivar. They indicate that tree architectural plasticity in response to its root system mainly derives from the number of medium shoots developed and follows priorities within the whole tree axis population. There was also evidence for dwarfing rootstock involvement in adjusting the flowering abundance and that differences in flowering occurrence take precedence over those regarding vegetative growth during tree development.

Regulation of early human growth: impact on long-term health.

PubMed

Koletzko, Berthold; Chourdakis, Michael; Grote, Veit; Hellmuth, Christian; Prell, Christine; Rzehak, Peter; Uhl, Olaf; Weber, Martina

2014-01-01

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations. © 2014 S. Karger AG, Basel.

Climate Change Implications to Vegetation Production in Alaska

NASA Technical Reports Server (NTRS)

Neigh, Christopher S.R.

2008-01-01

Investigation of long-term meteorological satellite data revealed statistically significant vegetation response to climate drivers of temperature, precipitation and solar radiation with exclusion of fire disturbance in Alaska. Abiotic trends were correlated to satellite remote sensing observations of normalized difference vegetation index to understand biophysical processes that could impact ecosystem carbon storage. Warming resulted in disparate trajectories for vegetation growth due to precipitation and photosynthetically active radiation variation. Interior spruce forest low lands in late summer through winter had precipitation deficit which resulted in extensive fire disturbance and browning of undisturbed vegetation with reduced post-fire recovery while Northern slope moist alpine tundra had increased production due to warmer-wetter conditions during the late 1990s and early 2000s. Coupled investigation of Alaska s vegetation response to warming climate found spatially dynamic abiotic processes with vegetation browning not a result from increased fire disturbance.

The limited importance of size-asymmetric light competition and growth of pioneer species in early secondary forest succession in Vietnam.

PubMed

van Kuijk, Marijke; Anten, N P R; Oomen, R J; van Bentum, D W; Werger, M J A

2008-08-01

It is generally believed that asymmetric competition for light plays a predominant role in determining the course of succession by increasing size inequalities between plants. Size-related growth is the product of size-related light capture and light-use efficiency (LUE). We have used a canopy model to calculate light capture and photosynthetic rates of pioneer species in sequential vegetation stages of a young secondary forest stand. Growth of the same saplings was followed in time as succession proceeded. Photosynthetic rate per unit plant mass (P(mass): mol C g(-1) day(-1)), a proxy for plant growth, was calculated as the product of light capture efficiency [Phi(mass): mol photosynthetic photon flux density (PPFD) g(-1) day(-1)] and LUE (mol C mol PPFD(-1)). Species showed different morphologies and photosynthetic characteristics, but their light-capturing and light-use efficiencies, and thus P (mass), did not differ much. This was also observed in the field: plant growth was not size-asymmetric. The size hierarchy that was present from the very early beginning of succession remained for at least the first 5 years. We conclude, therefore, that in slow-growing regenerating vegetation stands, the importance of asymmetric competition for light and growth can be much less than is often assumed.

Reproduction and vegetative growth in the dioecious shrub Acer barbinerve in temperate forests of Northeast China.

PubMed

Wang, Juan; Zhang, Chunyu; Gadow, Klaus V; Cheng, Yanxia; Zhao, Xiuhai

2015-06-01

Trade-off in dioecious plant. The trade-off between reproduction, vegetative growth and maintenance is a major issue in the life history of an organism and a record of the process which is producing the largest possible number of living offspring by natural selection. Dioecious species afford an excellent opportunity for detecting such possible trade-offs in resource allocation. In this study, we selected the dioecious shrub Acer barbinerve to examine possible trade-offs between reproduction and vegetative growth in both genders at different modular levels during three successive years. Reproductive and vegetative biomass values were assessed during successive years to evaluate their intra-annual and inter-annual trade-offs. These trade-offs were examined at shoot, branch and shrub modular levels in Acer barbinerve shrubs. An intra-annual trade-off was detected at the shoot level for both genders in 2011 and 2012. Both males and females showed a negative correlation between reproduction and vegetative growth, but this was more prominent in males. For the females of the species, inter-annual trade-offs were only found at branch and shrub levels. Slightly negative correlations in females were detected between the reproduction in 2012 and the reproduction in the two previous years. The gender ratio was significantly male biased during the three successive years of our investigation. Females had higher mortality rates in the larger diameter classes, both in 2011 and 2012. This study revealed a clear trade-off between reproduction and vegetative growth in Acer barbinerve, but results varied between males and females. The degree of autonomy of the different modular levels may affect the ability to detect such trade-offs.

Changes in Spring Vegetation Activity over Eurasian Boreal Forest Associated with Reduction of Arctic Sea Ice

NASA Astrophysics Data System (ADS)

Koh, Y.; Jeong, J. H.; Kim, B. M.; Park, T. W.; Jeong, S. J.

2017-12-01

Vegetation activities over the high-latitude in the Northern-Hemisphere are known to be very sensitive to climate change, which can, in turn, affect the entire climate system. This is one of the important feedback effects on global climate change. In this study, we have detected a declining trend of vegetation index in the boreal forest (Taiga) region of Eurasia in early spring from the late 1990s, and confirmed that the cause is closely related to the decrease in winter temperature linked to the Arctic sea ice change. The reduction of Arctic sea ice induces weakening of the Polar vortex around the Arctic, which has a chilling effect throughout Eurasia until the early spring (March) by strengthening the Siberian high in the Eurasian continent. The decrease of vegetation growth is caused by the extreme cold phenomenon directly affecting the growth of the boreal trees. To verify this, we used vegetation-climate coupled models to investigate climate-vegetation sensitivity to sea ice reduction. As a result, when the Arctic sea ice decreased in the model simulation, the vegetation index of the boreal forest, especially needleleaf evergreen trees, decreased as similarly detected by observations.

Vegetative growth and cluster development in Shiraz grapevines subjected to partial root-zone cooling

PubMed Central

Rogiers, Suzy Y.; Clarke, Simon J.

2013-01-01

Heterogeneity in root-zone temperature both vertically and horizontally may contribute to the uneven vegetative and reproductive growth often observed across vineyards. An experiment was designed to assess whether the warmed half of a grapevine root zone could compensate for the cooled half in terms of vegetative growth and reproductive development. We divided the root system of potted Shiraz grapevines bilaterally and applied either a cool or a warm treatment to each half from budburst to fruit set. Shoot growth and inflorescence development were monitored over the season. Simultaneous cooling and warming of parts of the root system decreased shoot elongation, leaf emergence and leaf expansion below that of plants with a fully warmed root zone, but not to the same extent as those with a fully cooled root zone. Inflorescence rachis length, flower number and berry number after fertilization were smaller only in those vines exposed to fully cooled root zones. After terminating the treatments, berry enlargement and the onset of veraison were slowed in those vines that had been exposed to complete or partial root-zone cooling. Grapevines exposed to partial root-zone cooling were thus delayed in vegetative and reproductive development, but the inhibition was greater in those plants whose entire root system had been cooled. PMID:24244839

Ethylene and Hormonal Cross Talk in Vegetative Growth and Development.

PubMed

Van de Poel, Bram; Smet, Dajo; Van Der Straeten, Dominique

2015-09-01

Ethylene is a gaseous plant hormone that most likely became a functional hormone during the evolution of charophyte green algae, prior to land colonization. From this ancient origin, ethylene evolved into an important growth regulator that is essential for myriad plant developmental processes. In vegetative growth, ethylene appears to have a dual role, stimulating and inhibiting growth, depending on the species, tissue, and cell type, developmental stage, hormonal status, and environmental conditions. Moreover, ethylene signaling and response are part of an intricate network in cross talk with internal and external cues. Besides being a crucial factor in the growth control of roots and shoots, ethylene can promote flowering, fruit ripening and abscission, as well as leaf and petal senescence and abscission and, hence, plays a role in virtually every phase of plant life. Last but not least, together with jasmonates, salicylate, and abscisic acid, ethylene is important in steering stress responses. © 2015 American Society of Plant Biologists. All Rights Reserved.

Simulating the onset of spring vegetation growth across the Northern Hemisphere.

PubMed

Liu, Qiang; Fu, Yongshuo H; Liu, Yongwen; Janssens, Ivan A; Piao, Shilong

2018-03-01

Changes in the spring onset of vegetation growth in response to climate change can profoundly impact climate-biosphere interactions. Thus, robust simulation of spring onset is essential to accurately predict ecosystem responses and feedback to ongoing climate change. To date, the ability of vegetation phenology models to reproduce spatiotemporal patterns of spring onset at larger scales has not been thoroughly investigated. In this study, we took advantage of phenology observations via remote sensing to calibrate and evaluated six models, including both one-phase (considering only forcing temperatures) and two-phase (involving forcing, chilling, and photoperiod) models across the Northern Hemisphere between 1982 and 2012. Overall, we found that the model that integrated the photoperiod effect performed best at capturing spatiotemporal patterns of spring phenology in boreal and temperate forests. By contrast, all of the models performed poorly in simulating the onset of growth in grasslands. These results suggest that the photoperiod plays a role in controlling the onset of growth in most Northern Hemisphere forests, whereas other environmental factors (e.g., precipitation) should be considered when simulating the onset of growth in grasslands. We also found that the one-phase model performed as well as the two-phase models in boreal forests, which implies that the chilling requirement is probably fulfilled across most of the boreal zone. Conversely, two-phase models performed better in temperate forests than the one-phase model, suggesting that photoperiod and chilling play important roles in these temperate forests. Our results highlight the significance of including chilling and photoperiod effects in models of the spring onset of forest growth at large scales, and indicate that the consideration of additional drivers may be required for grasslands. © 2017 John Wiley & Sons Ltd.

Intensive ground vegetation growth mitigates the carbon loss after forest disturbance.

PubMed

Zehetgruber, Bernhard; Kobler, Johannes; Dirnböck, Thomas; Jandl, Robert; Seidl, Rupert; Schindlbacher, Andreas

2017-01-01

Slow or failed tree regeneration after forest disturbance is increasingly observed in the central European Alps, potentially amplifying the carbon (C) loss from disturbance. We aimed at quantifying C dynamics of a poorly regenerating disturbance site with a special focus on the role of non-woody ground vegetation. Soil CO 2 efflux, fine root biomass, ground vegetation biomass, tree increment and litter input were assessed in (i) an undisturbed section of a ~ 110 years old Norway spruce stand, (ii) in a disturbed section which was clear-cut six years ago (no tree regeneration), and (iii) in a disturbed section which was clear-cut three years ago (no tree regeneration). Total soil CO 2 efflux was similar across all stand sections (8.5 ± 0.2 to 8.9 ± 0.3 t C ha -1  yr. -1 ). The undisturbed forest served as atmospheric C sink (2.1 t C ha -1  yr. -1 ), whereas both clearings were C sources to the atmosphere. The source strength three years after disturbance (-5.5 t C ha -1  yr. -1 ) was almost twice as high as six years after disturbance (-2.9 t C ha -1  yr. -1 ), with declining heterotrophic soil respiration and the high productivity of dense graminoid ground vegetation mitigating C loss. C loss after disturbance decreases with time and ground vegetation growth. Dense non-woody ground vegetation cover can hamper tree regeneration but simultaneously decrease the ecosystem C loss. The role of ground vegetation should be more explicitly taken into account in forest C budgets assessing disturbance effects.

Early-warning signals for catastrophic soil degradation

NASA Astrophysics Data System (ADS)

Karssenberg, Derek

2010-05-01

Many earth systems have critical thresholds at which the system shifts abruptly from one state to another. Such critical transitions have been described, among others, for climate, vegetation, animal populations, and geomorphology. Predicting the timing of critical transitions before they are reached is of importance because of the large impact on nature and society associated with the transition. However, it is notably difficult to predict the timing of a transition. This is because the state variables of the system show little change before the threshold is reached. As a result, the precision of field observations is often too low to provide predictions of the timing of a transition. A possible solution is the use of spatio-temporal patterns in state variables as leading indicators of a transition. It is becoming clear that the critically slowing down of a system causes spatio-temporal autocorrelation and variance to increase before the transition. Thus, spatio-temporal patterns are important candidates for early-warning signals. In this research we will show that these early-warning signals also exist in geomorphological systems. We consider a modelled vegetation-soil system under a gradually increasing grazing pressure causing an abrupt shift towards extensive soil degradation. It is shown that changes in spatio-temporal patterns occur well ahead of this catastrophic transition. A distributed model describing the coupled processes of vegetation growth and geomorphological denudation is adapted. The model uses well-studied simple process representations for vegetation and geomorphology. A logistic growth model calculates vegetation cover as a function of grazing pressure and vegetation growth rate. Evolution of the soil thickness is modelled by soil creep and wash processes, as a function of net rain reaching the surface. The vegetation and soil system are coupled by 1) decreasing vegetation growth with decreasing soil thickness and 2) increasing soil wash with

Estimating plant biomass in early-successional subtropical vegetation using a visual obstruction technique

Treesearch

Genie M. Fleming; Joseph M. Wunderle; David N. Ewert; Joseph O' Brien

2014-01-01

Aim: Non-destructive methods for quantifying above-ground plant biomass are important tools in many ecological studies and management endeavours, but estimation methods can be labour intensive and particularly difficult in structurally diverse vegetation types. We aimed to develop a low-cost, but reasonably accurate, estimation technique within early-successional...

A general theory of early growth?. Comment on: "Mathematical models to characterize early epidemic growth: A review" by Gerardo Chowell et al.

NASA Astrophysics Data System (ADS)

House, Thomas

2016-09-01

Chowell et al. [1] consider the early growth behaviour of various epidemic models that range from phenomenological approaches driven by data to mechanistic descriptions of complex interactions between individuals. This is particularly timely given the recent Ebola epidemic, although non-exponential early growth may be more common (but less immediately evident) than we realise.

Effect of nitrogen gas packaging on the quality and microbial growth of fresh-cut vegetables under low temperatures.

PubMed

Koseki, Shigenobu; Itoh, Kazuhiko

2002-02-01

Nitrogen (N2) gas packaging for fresh-cut vegetables (lettuce and cabbage) has been examined as a means of modified atmosphere packaging (MAP) for extending the shelf life of cut vegetables. Gas composition in enclosed packages that contained cut vegetables and were filled with 100% N2 had an oxygen (O2) concentration of 1.2 to 5.0% and a carbon dioxide (CO2) concentration of 0.5 to 3.5% after 5 days of storage. An atmosphere of low concentrations of O2 and high CO2 conditions occurred naturally in the package filled with N2 gas. Degradation of cut vegetables in terms of appearance was delayed by N2 gas packaging. Because of this effect, the appearance of fresh-cut vegetables packaged with N2 gas remained acceptable at temperatures below 5 degrees C after 5 days. Treatment with acidic electrolyzed water (AcEW) contributed to the acceptability of the vegetables' appearance at 5 and 10 degrees C in the air-packaging system. N2 gas packaging did not significantly affect the growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) in or on cut vegetables at 1, 5, and 10 degrees C for 5 days. Microbial growth in or on the cut vegetables was inhibited at 1 degrees C for 5 days regardless of atmospheric conditions.

Stimulating seedling growth in early stages of secondary forest succession: a modeling approach to guide tree liberation

PubMed Central

van Kuijk, Marijke; Anten, Niels P. R.; Oomen, Roelof J.; Schieving, Feike

2014-01-01

Excessive growth of non-woody plants and shrubs on degraded lands can strongly hamper tree growth and thus secondary forest succession. A common method to accelerate succession, called liberation, involves opening up the vegetation canopy around young target trees. This can increase growth of target trees by reducing competition for light with neighboring plants. However, liberation has not always had the desired effect, likely due to differences in light requirement between tree species. Here we present a 3D-model, which calculates photosynthetic rate of individual trees in a vegetation stand. It enables us to examine how stature, crown structure, and physiological traits of target trees and characteristics of the surrounding vegetation together determine effects of light on tree growth. The model was applied to a liberation experiment conducted with three pioneer species in a young secondary forest in Vietnam. Species responded differently to the treatment depending on their height, crown structure and their shade-tolerance level. Model simulations revealed practical thresholds over which the tree growth response is heavily influenced by the height and density of surrounding vegetation and gap radius. There were strong correlations between calculated photosynthetic rates and observed growth: the model was well able to predict growth of trees in young forests and the effects of liberation there upon. Thus, our model serves as a useful tool to analyze light competition between young trees and surrounding vegetation and may help assess the potential effect of tree liberation. PMID:25101100

Interannual growth dynamics of vegetation in the Kuparuk River watershed, Alaska based on the Normalized Difference Vegetation Index

USGS Publications Warehouse

Hope, A.S.; Boynton, W.L.; Stow, D.A.; Douglas, David C.

2003-01-01

Interannual above-ground production patterns are characterized for three tundra ecosystems in the Kuparuk River watershed of Alaska using NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) data. NDVI values integrated over each growing season (SINDVI) were used to represent seasonal production patterns between 1989 and 1996. Spatial differences in ecosystem production were expected to follow north-south climatic and soil gradients, while interannual differences in production were expected to vary with variations in seasonal precipitation and temperature. It was hypothesized that the increased vegetation growth in high latitudes between 1981 and 1991 previously reported would continue through the period of investigation for the study watershed. Zonal differences in vegetation production were confirmed but interannual variations did not covary with seasonal precipitation or temperature totals. A sharp reduction in the SINDVI in 1992 followed by a consistent increase up to 1996 led to a further hypothesis that the interannual variations in SINDVI were associated with variations in stratospheric optical depth. Using published stratospheric optical depth values derived from the SAGE and SAGE-II satellites, it is demonstrated that variations in these depths are likely the primary cause of SINDVI interannual variability.

Ethylene and Hormonal Cross Talk in Vegetative Growth and Development1

PubMed Central

Van de Poel, Bram; Smet, Dajo; Van Der Straeten, Dominique

2015-01-01

Ethylene is a gaseous plant hormone that most likely became a functional hormone during the evolution of charophyte green algae, prior to land colonization. From this ancient origin, ethylene evolved into an important growth regulator that is essential for myriad plant developmental processes. In vegetative growth, ethylene appears to have a dual role, stimulating and inhibiting growth, depending on the species, tissue, and cell type, developmental stage, hormonal status, and environmental conditions. Moreover, ethylene signaling and response are part of an intricate network in cross talk with internal and external cues. Besides being a crucial factor in the growth control of roots and shoots, ethylene can promote flowering, fruit ripening and abscission, as well as leaf and petal senescence and abscission and, hence, plays a role in virtually every phase of plant life. Last but not least, together with jasmonates, salicylate, and abscisic acid, ethylene is important in steering stress responses. PMID:26232489

Disentangling the Effects of Water Stress on Carbon Acquisition, Vegetative Growth, and Fruit Quality of Peach Trees by Means of the QualiTree Model.

PubMed

Rahmati, Mitra; Mirás-Avalos, José M; Valsesia, Pierre; Lescourret, Françoise; Génard, Michel; Davarynejad, Gholam H; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles

2018-01-01

Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree) was adapted for describing the water stress effects on peach ( Prunus persica L. Batsch) vegetative growth, fruit size and composition. First, an energy balance calculation at the fruit-bearing shoot level and a water transfer formalization within the plant were integrated into the model. Next, a reduction function of vegetative growth according to tree water status was added to QualiTree. Then, the model was parameterized and calibrated for a late-maturing peach cultivar ("Elberta") under semi-arid conditions, and for three different irrigation practices. Simulated vegetative and fruit growth variability over time was consistent with observed data. Sugar concentrations in fruit flesh were well simulated. Finally, QualiTree allowed for determining the relative importance of photosynthesis and vegetative growth reduction on carbon acquisition, plant growth and fruit quality under water constrains. According to simulations, water deficit impacted vegetative growth first through a direct effect on its sink strength

Stock size affects early growth of a loblolly pine

Treesearch

David B. South; Al Lyons; Russ Pohl

2015-01-01

For decades, forest researchers in the South have known that early gains in survival and growth of loblolly pine (Pinus taeda L.) can be achieved by planting large-diameter seedlings (South 1993; Wakeley 1949). For P. radiata, increasing size of planting stock also increases early growth of both seedlings (Mason and others 1996) and cuttings (South and others 2005)....

Prediction of microbial growth in fresh-cut vegetables treated with acidic electrolyzed water during storage under various temperature conditions.

PubMed

Koseki, S; Itoh, K

2001-12-01

Effects of storage temperature (1, 5, and 10 degrees C) on growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) on acidic electrolyzed water (AcEW)-treated fresh-cut lettuce and cabbage were determined. A modified Gompertz function was used to describe the kinetics of microbial growth. Growth data were analyzed using regression analysis to generate "best-fit" modified Gompertz equations, which were subsequently used to calculate lag time, exponential growth rate, and generation time. The data indicated that the growth kinetics of each bacterium were dependent on storage temperature, except at 1 degrees C storage. At 1 degrees C storage, no increases were observed in bacterial populations. Treatment of vegetables with AcEW produced a decrease in initial microbial populations. However, subsequent growth rates were higher than on nontreated vegetables. The recovery time required by the reduced microbial population to reach the initial (treated with tap water [TW]) population was also determined in this study, with the recovery time of the microbial population at 10 degrees C being <3 days. The benefits of reducing the initial microbial populations on fresh-cut vegetables were greatly affected by storage temperature. Results from this study could be used to predict microbial quality of fresh-cut lettuce and cabbage throughout their distribution.

On the relative magnitudes of photosynthesis, respiration, growth and carbon storage in vegetation

NASA Astrophysics Data System (ADS)

van Oijen, M.

2012-04-01

• Background and Aims. The carbon balance of vegetation is dominated by the two large fluxes of photosynthesis (P) and respiration (R). Mechanistic models have attempted to simulate the two fluxes separately, each with their own set of internal and external controls. This has led to model predictions where environmental change causes R to exceed P, with consequent dieback of vegetation. However, empirical evidence suggests that the R:P ratio is constrained to a narrow range of about 0.4-0.5. Physiological explanations for the narrow range are not conclusive. We aim to introduce a novel perspective by theoretical study of the quantitative relationship between the four carbon fluxes of P, R, growth and storage (or its inverse, remobilisation). • Methods. Starting from the law of conservation of mass - in this case carbon - we derive equations for the relative magnitudes of all carbon fluxes which depend on only two parameters: the R:P ratio and the relative rate of storage of carbon into remobilisable reserves. The equations are used to explain observed flux ratios and to analyse incomplete data sets of carbon fluxes. • Key Results. Storage rate is shown to be a freely varying parameter, whereas R:P is narrowly constrained. This explains the constancy of the ratio reported in the literature. With the information thus gained, a data set of R and P in grassland was analysed, and flux estimates could be derived for the periods after cuts in which plant growth is dominated by remobilisation before photosynthesis takes over. • Conclusions. We conclude that the relative magnitudes of photosynthesis, respiration, growth and substrate storage are indeed tightly constrained, but because of mass conservation rather than for physiological reasons. This facilitates analysis of incomplete data sets. Mechanistic models, as the embodiment of physiological mechanisms, need to show consistency with the constraints. • Reference. Van Oijen, M., Schapendonk, A. & Höglind, M

Effect of aluminum stress in early-stage growth of soybean

NASA Astrophysics Data System (ADS)

Sagala, D.; Suzanna, E.; Prihanani; Ghulamahdi, M.; Lubis, I.; Trikoesoemaningtyas

2018-04-01

The sensitivity of soybean to aluminum stress is well known. One of the abiotic stresses in tidal swamps is the aluminum toxicity. Therefore, it is necessary to find the appropriate management and cropping pattern to obtain a high yield of soybean in the tidal land. We supposed that it would be related to the development stage of soybean. This study was aimed to find the most sensitive of soybean vegetative growth stage to aluminum. Three cultivars of soybean (tanggamus, Karasumame, and M652) and four aluminum treatments (control, 10 days after planting/DAP, 20 DAP, 30 DAP) were arranged in a completely randomized design with three replications. Measurements have been made on root length, root/shoot ratio, biomass dry weight, leaves Aluminum content, leaves the area, and sensitivity index. Overall, observation results indicate that the earlier soybean experience aluminum stress, the more its vegetative growth is disturbed.

Semi-determinate growth habit adjusts the vegetative-to-reproductive balance and increases productivity and water-use efficiency in tomato (Solanum lycopersicum).

PubMed

Vicente, Mateus Henrique; Zsögön, Agustin; de Sá, Ariadne Felicio Lopo; Ribeiro, Rafael V; Peres, Lázaro E P

2015-04-01

Tomato (Solanum lycopersicum) shows three growth habits: determinate, indeterminate and semi-determinate. These are controlled mainly by allelic variation in the self-pruning (SP) gene family, which also includes the "florigen" gene single flower TRUSS (SFT). Determinate cultivars have synchronized flower and fruit production, which allows mechanical harvesting in the tomato processing industry, whereas indeterminate ones have more vegetative growth with continuous flower and fruit formation, being thus preferred for fresh market tomato production. The semi-determinate growth habit is poorly understood, although there are indications that it combines advantages of determinate and indeterminate growth. Here, we used near-isogenic lines (NILs) in the cultivar Micro-Tom (MT) with different growth habit to characterize semi-determinate growth and to determine its impact on developmental and productivity traits. We show that semi-determinate genotypes are equivalent to determinate ones with extended vegetative growth, which in turn impacts shoot height, number of leaves and either stem diameter or internode length. Semi-determinate plants also tend to increase the highly relevant agronomic parameter Brix × ripe yield (BRY). Water-use efficiency (WUE), evaluated either directly as dry mass produced per amount of water transpired or indirectly through C isotope discrimination, was higher in semi-determinate genotypes. We also provide evidence that the increases in BRY in semi-determinate genotypes are a consequence of an improved balance between vegetative and reproductive growth, a mechanism analogous to the conversion of the overly vegetative tall cereal varieties into well-balanced semi-dwarf ones used in the Green Revolution. Copyright © 2015 Elsevier GmbH. All rights reserved.

The impacts of the dust radiative effect on vegetation growth in the Sahel

NASA Astrophysics Data System (ADS)

Evans, S. M.; Shevliakova, E.; Malyshev, S.; Ginoux, P. A.

2017-12-01

Many studies have been conducted on the effects of dust on rainfall in the Sahel, and generally show that African dust weakens the West African Monsoon, drying the region. This drying is often assumed to reduce vegetation cover for the region, providing a positive feedback with dust emission. There are, however, other competing effects of dust that are also important to plant growth, including a reduction in surface temperature, a reduction in downwelling solar radiation, and an increase in the diffuse fraction of that solar radiation. Using the NOAA/GFDL CM3 model coupled to the dynamic vegetation model LM3, we demonstrate that the combined effect of all these processes is to decrease the vegetation coverage and productivity of the Sahel and West Africa. We accomplish this by comparing experiments with radiatively active dust to experiments with radiatively invisible dust. We find that in modern conditions, the dust radiative effect reduces the net primary productivity of West Africa and the Sahel by up to 30% locally, and when summed over the region accounts for a difference of approximately 0.4 GtC per year. Experiments where the vegetation experiences preindustrial rather than modern CO2 levels show that without carbon fertilization, this loss of productivity would be approximately 10% stronger. In contrast, during preindustrial conditions the vegetation response is less than half as strong, despite the dust induced rainfall and temperature anomalies being similar. We interpret this as the vegetation being less susceptible to drought in a less evaporative climate. These changes in vegetation create the possibility of a dust-vegetation feedback loop whose strength varies with the mean state of the climate, and which may grow stronger in the future.

Effect of salt stress on morpho-physiology, vegetative growth and yield of rice.

PubMed

Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Ali, E; Ismail, Mohd Razi; Selamat, Ahmed; Karim, S M Rezaul

2014-03-01

Selection of salt tolerant rice varieties has a huge impact on global food supply chain. Five Malaysian rice (Oryza sativa L.) varieties, MR33, MR52, MR211, MR219 and MR232 were tested in pot experiment under different salinity levels for their response in term of vegetative growth, physiological activities, development of yield components and grain yield. Rice varieties, BRRI dhan29 and IR20 were used as a salt-sensitive control and Pokkali was used as a salt-tolerant control. Three different salinity levels viz. 4, 8, and 12 dS m(-1) were used in a randomized complete block design with four replications under glass house conditions. Two Malaysia varieties, MR211 and MR232 performed better in terms of vegetative growth (plant height, leaf area plant(-1), number of tillers plant(-1), dry matter accumulation plant(-1)), photosynthetic rate, transpiration rate, yield components, grain yield and injury symptoms. While, MR33, MR52 and MR219 verities were able to withstand salinity stress over salt-sensitive control, BRRI dhan29 and IR20.

Response of avian communities to herbicide-induced vegetation changes

USGS Publications Warehouse

Morrison, M.L.; Meslow, E.C.

1984-01-01

The relationships between avian communities and herbicide modification of vegetation were analyzed on early-growth clear-cuts in western Oregon that had received phenoxy herbicide treatment 1 or 4 years previously. For both 1 and 4 years post-spray, vegetation development was greater in the third height interval (> 3.0 m) on untreated sites. All measures of vegetative diversity on untreated sites exceeded those on treated sites. Overall density and diversity of birds were similar between treated and untreated sites. Several bird species altered their foraging behavior on treated sites, i.e., birds using deciduous trees increased use of shrubs on treated sites. The primary effect of herbicide application was a reduction in the complexity of vegetation, a condition due primarity to the removal of deciduous trees. Small patches of deciduous trees scattered in clear-cuts treated with phenoxy herbicides can maintain an avian community similar to that on untreated sites.

Fruit and Vegetable Intake During Infancy and Early Childhood

PubMed Central

Kim, Sonia A.; Yaroch, Amy L.; Scanlon, Kelley S.

2014-01-01

OBJECTIVES: To examine the association of timing of introduction and frequency of fruit and vegetable intake during infancy with frequency of fruit and vegetable intake at age 6 years in a cohort of US children. METHODS: We analyzed data on fruit and vegetable intake during late infancy, age of fruit and vegetable introduction, and frequency of fruit and vegetable intake at 6 years from the Infant Feeding Practices Study II and the Year 6 Follow-Up (Y6FU) Study. We determined the percent of 6-year-old children consuming fruits and vegetables less than once per day and examined associations with infant fruit and vegetable intake using logistic regression modeling, controlling for multiple covariates (n = 1078). RESULTS: Based on maternal report, 31.9% of 6-year-old children consumed fruit less than once daily and 19.0% consumed vegetables less than once daily. In adjusted analyses, children who consumed fruits and vegetables less than once daily during late infancy had increased odds of eating fruits and vegetables less than once daily at age 6 years (fruit, adjusted odds ratio: 2.48; vegetables, adjusted odds ratio: 2.40). Age of introduction of fruits and vegetables was not associated with intake at age 6 years. CONCLUSIONS: Our study suggests that infrequent intake of fruits and vegetables during late infancy is associated with infrequent intake of these foods at 6 years of age. These findings highlight the importance of infant feeding guidance that encourages intake of fruits and vegetables and the need to examine barriers to fruit and vegetable intake during infancy. PMID:25183758

Transcriptomic profile of leg muscle during early growth in chicken

PubMed Central

Zhang, Genxi; Li, Tingting; Ling, Jiaojiao; Zhang, Xiangqian; Wang, Jinyu

2017-01-01

The early growth pattern, especially the age of peak growth, of broilers affects the time to market and slaughter weight, which in turn affect the profitability of the poultry industry. However, the underlying mechanisms regulating chicken growth and development have rarely been studied. This study aimed to identify candidate genes involved in chicken growth and investigated the potential regulatory mechanisms of early growth in chicken. RNA sequencing was applied to compare the transcriptomes of chicken muscle tissues at three developmental stages during early growth. In total, 978 differentially expressed genes (DEGs) (fold change ≥ 2; false discovery rate < 0.05) were detected by pairwise comparison. Functional analysis showed that the DEGs are mainly involved in the processes of cell growth, muscle development, and cellular activities (such as junction, migration, assembly, differentiation, and proliferation). Many of the DEGs are well known to be related to chicken growth, such as MYOD1, GH, IGF2BP2, IGFBP3, SMYD1, CEBPB, FGF2, and IGFBP5. KEGG pathway analysis identified that the DEGs were significantly enriched in five pathways (P < 0.1) related to growth and development: extracellular matrix–receptor interaction, focal adhesion, tight junction, insulin signaling pathway, and regulation of the actin cytoskeleton. A total of 42 DEGs assigned to these pathways are potential candidate genes inducing the difference in growth among the three developmental stages, such as MYH10, FGF2, FGF16, FN1, CFL2, MAPK9, IRS1, PHKA1, PHKB, and PHKG1. Thus, our study identified a series of genes and several pathways that may participate in the regulation of early growth in chicken. These results should serve as an important resource revealing the molecular basis of chicken growth and development. PMID:28291821

Fruit and vegetable intake during infancy and early childhood.

PubMed

Grimm, Kirsten A; Kim, Sonia A; Yaroch, Amy L; Scanlon, Kelley S

2014-09-01

To examine the association of timing of introduction and frequency of fruit and vegetable intake during infancy with frequency of fruit and vegetable intake at age 6 years in a cohort of US children. We analyzed data on fruit and vegetable intake during late infancy, age of fruit and vegetable introduction, and frequency of fruit and vegetable intake at 6 years from the Infant Feeding Practices Study II and the Year 6 Follow-Up (Y6FU) Study. We determined the percent of 6-year-old children consuming fruits and vegetables less than once per day and examined associations with infant fruit and vegetable intake using logistic regression modeling, controlling for multiple covariates (n = 1078). Based on maternal report, 31.9% of 6-year-old children consumed fruit less than once daily and 19.0% consumed vegetables less than once daily. In adjusted analyses, children who consumed fruits and vegetables less than once daily during late infancy had increased odds of eating fruits and vegetables less than once daily at age 6 years (fruit, adjusted odds ratio: 2.48; vegetables, adjusted odds ratio: 2.40). Age of introduction of fruits and vegetables was not associated with intake at age 6 years. Our study suggests that infrequent intake of fruits and vegetables during late infancy is associated with infrequent intake of these foods at 6 years of age. These findings highlight the importance of infant feeding guidance that encourages intake of fruits and vegetables and the need to examine barriers to fruit and vegetable intake during infancy. Copyright © 2014 by the American Academy of Pediatrics.

Sildenafil citrate therapy for severe early-onset intrauterine growth restriction.

PubMed

von Dadelszen, P; Dwinnell, S; Magee, L A; Carleton, B C; Gruslin, A; Lee, B; Lim, K I; Liston, R M; Miller, S P; Rurak, D; Sherlock, R L; Skoll, M A; Wareing, M M; Baker, P N

2011-04-01

Sildenafil citrate therapy for severe early-onset intrauterine growth restriction. BJOG 2011;118:624-628. Currently, there is no effective therapy for severe early-onset intrauterine growth restriction (IUGR). Sildenafil citrate vasodilates the myometrial arteries isolated from women with IUGR-complicated pregnancies. Women were offered Sildenafil (25 mg three times daily until delivery) if their pregnancy was complicated by early-onset IUGR [abdominal circumference (AC)< 5th percentile] and either the gestational age was <25(+0) weeks or an estimate of the fetal weight was <600 g (excluding known fetal anomaly/syndrome and/or planned termination). Sildenafil treatment was associated with increased fetal AC growth [odds ratio, 12.9; 95% confidence interval (CI), 1.3, 126; compared with institutional Sildenafil-naive early-onset IUGR controls]. Randomised controlled trial data are required to determine whether Sildenafil improves perinatal outcomes for early-onset IUGR-complicated pregnancies. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.

Impact of changes in GRACE derived terrestrial water storage on vegetation growth in Eurasia

NASA Astrophysics Data System (ADS)

A, G.; Velicogna, I.; Kimball, J. S.; Kim, Y.

2015-12-01

We use GRACE-derived terrestrial water storage (TWS) and ERA-interim air temperature, as proxy for available water and temperature constraints on vegetation productivity, inferred from MODIS satellite normalized difference vegetation index (NDVI), in Northern Eurasia during 2002-2011. We investigate how changes in TWS affect the correlation between NDVI and temperature during the non-frozen season. We find that vegetation growth exhibits significant spatial and temporal variability associated with varying trend in TWS and temperature. The largest NDVI gains occur over boreal forests associated with warming and wetting. The largest NDVI losses occur over grasslands in the Southwestern Ob associated with regional drying and cooling, with dominant constraint from TWS. Over grasslands and temperate forests in the Southeast Ob and South Yenisei, wetting and cooling lead to a dominant temperature constraint due to the relaxation of TWS constraints. Overall, we find significant monthly correlation of NDVI with TWS and temperature over 35% and 50% of the domain, respectively. These results indicate that water availability (TWS) plays a major role in modulating Eurasia vegetation response to temperature changes.

Understanding Large Wind Farm Impacts on Regional Climate and Vegetation Growth from Observational and Modeling Perspectives

NASA Astrophysics Data System (ADS)

Xia, Geng

In the most recent decade, wind energy has experienced exponential growth worldwide and this rapid increase is expected to continue, particularly over farmlands in the United States. This poses an important question regarding whether the widespread deployment of wind turbines (WTs) will influence surface/near-surface microclimate and vegetation growth. In this dissertation, I investigate the potential wind farm (WF) impacts on regional climate and vegetation growth from both observational and modeling perspectives. High resolution satellite, radiosonde and field observations are used to determine the magnitude and variability of WF-induced changes on surface/near-surface temperatures while the Weather Research and Forecasting (WRF) model is used to simulate these changes in real-world WFs at regional scales and to uncover the physical processes behind the simulated temperature changes. First, the primary physical mechanisms controlling the seasonal and diurnal variations of WF impacts on land surface temperature (LST) are investigated by analyzing both satellite data and field observations. It is found that the turbine-induced turbulent kinetic energy (TKE) relative to the background TKE determines the magnitude and variability of such impacts. In addition, atmospheric stability also matters in determining the sign and strength of the net downward heat transport as well as the magnitude of the background TKE. Second, the WRF's ability in simulating the observed WF impacts on LST is examined by conducting real-world WF experiments driven by realistic initial and boundary conditions. Overall, the WRF model can moderately reproduce the observed spatiotemporal variations of the background LST but has difficulties in reproducing such variations for the turbine-induced LST change signals at pixel levels. However, the model is still able to reproduce the coherent and consistent responses of the observed WF-induced LST changes at regional scales. Third, the spatiotemporal

Application of the Forest Vegetation Simulator in evaluating management for old-growth characteristics in southwestern mixed conifer forests

Treesearch

Claudia M. Regan; Wayne D. Shepperd; Robert A. Obedzinski

1995-01-01

We used the Forest Vegetation Simulator (FVS) and GRAFM graphics display to investigate conditions associated with the stability of an old-growth stand and to evaluate the potential for two managed stands of contrasting but representative conditions to develop structures similar to the old-growth stand. Simulations indicate that the example old-growth stand can retain...

Effects of competing vegetation on growth of loblolly pine plantations in the West Gulf Coastal Plain

Treesearch

Dean W. Coble

2015-01-01

Competing woody vegetation negatively affects the growth of planted loblolly pine (Pinus taeda L.) trees by seizing site resources that otherwise would be used by the planted trees (Burkhart and Sprinz 1984).

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

PubMed

Pound, Matthew J; Salzmann, Ulrich

2017-02-24

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

Effect of prior vegetative growth, inoculum density and light on conidiation in Erysiphe necator

USDA-ARS?s Scientific Manuscript database

A driving force in epidemics of grape powdery mildew is the abundant production of conidia. Our objective was to better define the three factors involved in the qualitative change that occurs when a mildew colony switches from vegetative growth to sporulation –inoculum density, light, and a sporulat...

Snow survey and vegetation growth in the Swiss Alps

NASA Technical Reports Server (NTRS)

Haefner, H. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Analog processing of S190A and B color and infrared color transparencies showed that it is possible to evaluate the courses of the temporary snow line and the upper limit of vegetation growth over large areas. By transferring the results from S190A onto a topo-map 1:200,000, an accuracy of + or - 50 m could be achieved. With S190B transferred onto a map 1:100,000, an accuracy of + or - 20 m was reached. Digital processing of S192 multispectral data allowed a separation of snow and clouds by combining the information from channels 9, 15, and 18.

Mathematical models to characterize early epidemic growth: A Review

PubMed Central

Chowell, Gerardo; Sattenspiel, Lisa; Bansal, Shweta; Viboud, Cécile

2016-01-01

There is a long tradition of using mathematical models to generate insights into the transmission dynamics of infectious diseases and assess the potential impact of different intervention strategies. The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing reliable models that capture the baseline transmission characteristics of specific pathogens and social contexts. More refined models are needed however, in particular to account for variation in the early growth dynamics of real epidemics and to gain a better understanding of the mechanisms at play. Here, we review recent progress on modeling and characterizing early epidemic growth patterns from infectious disease outbreak data, and survey the types of mathematical formulations that are most useful for capturing a diversity of early epidemic growth profiles, ranging from sub-exponential to exponential growth dynamics. Specifically, we review mathematical models that incorporate spatial details or realistic population mixing structures, including meta-population models, individual-based network models, and simple SIR-type models that incorporate the effects of reactive behavior changes or inhomogeneous mixing. In this process, we also analyze simulation data stemming from detailed large-scale agent-based models previously designed and calibrated to study how realistic social networks and disease transmission characteristics shape early epidemic growth patterns, general transmission dynamics, and control of international disease emergencies such as the 2009 A/H1N1 influenza pandemic and the 2014-15 Ebola epidemic in West Africa. PMID:27451336

Mathematical models to characterize early epidemic growth: A review

NASA Astrophysics Data System (ADS)

Chowell, Gerardo; Sattenspiel, Lisa; Bansal, Shweta; Viboud, Cécile

2016-09-01

There is a long tradition of using mathematical models to generate insights into the transmission dynamics of infectious diseases and assess the potential impact of different intervention strategies. The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing reliable models that capture the baseline transmission characteristics of specific pathogens and social contexts. More refined models are needed however, in particular to account for variation in the early growth dynamics of real epidemics and to gain a better understanding of the mechanisms at play. Here, we review recent progress on modeling and characterizing early epidemic growth patterns from infectious disease outbreak data, and survey the types of mathematical formulations that are most useful for capturing a diversity of early epidemic growth profiles, ranging from sub-exponential to exponential growth dynamics. Specifically, we review mathematical models that incorporate spatial details or realistic population mixing structures, including meta-population models, individual-based network models, and simple SIR-type models that incorporate the effects of reactive behavior changes or inhomogeneous mixing. In this process, we also analyze simulation data stemming from detailed large-scale agent-based models previously designed and calibrated to study how realistic social networks and disease transmission characteristics shape early epidemic growth patterns, general transmission dynamics, and control of international disease emergencies such as the 2009 A/H1N1 influenza pandemic and the 2014-2015 Ebola epidemic in West Africa.

Vegetable Production System (Veggie)

NASA Technical Reports Server (NTRS)

Levine, Howard G.; Smith, Trent M.

2016-01-01

The Vegetable Production System (Veggie) was developed by Orbital Technologies Corp. to be a simple, easily stowed, and high growth volume yet low resource facility capable of producing fresh vegetables on the International Space Station (ISS). In addition to growing vegetables in space, Veggie can support a variety of experiments designed to determine how plants respond to microgravity, provide real-time psychological benefits for the crew, and conduct outreach activities. Currently, Veggie provides the largest volume available for plant growth on the ISS.

Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir in the Oregon Cascades.

Treesearch

Vern P. Yerkes

1960-01-01

Land managers often express a need for more complete information about the vegetative cover that develops on cutover areas between harvest of old-growth Douglas-fir (Pseudotsuga menziesii) and establishment of a young-growth forest. The composition and density of this cover frequently determines the management techniques that must be used to...

Vegetation Coverage Mapping and Soil Effect Correction in Estimating Vegetation Water Content and Dry Biomass from Satellites

NASA Astrophysics Data System (ADS)

Huang, J.; Chen, D.

2005-12-01

Vegetation water content (VWC) attracts great research interests in hydrology research in recent years. As an important parameter describing the horizontal expansion of vegetation, vegetation coverage is essential to implement soil effect correction for partially vegetated fields to estimate VWC accurately. Ground measurements of corn and soybeans in SMEX02 resulted in an identical expolinear relationship between vegetation coverage and leaf area index (LAI), which is used for vegetation coverage mapping. Results illustrated two parts of LAI growth quantitatively: the horizontal expansion of leaf coverage and the vertical accumulation of leaf layers. It is believed that the former part contributes significantly to LAI growth at initial vegetation growth stage and the latter is more dominant after vegetation coverage reaches a certain level. The Normalized Difference Water Index (NDWI) using short-wave infrared bands is convinced for its late saturation at high LAI values, in contrast to the Normalized Difference Vegetation Index (NDVI). NDWI is then utilized to estimate LAI, via another expolinear relationship, which is evidenced having vegetation species independency in study of corn and soybeans in SMEX02 sites. It is believed that the surface reflectance measured at satellites spectral bands are the mixed results of signals reflected from vegetation and bare soil, especially at partially vegetated fields. A simple linear mixture model utilizing vegetation coverage information is proposed to correct soil effect in such cases. Surface reflectance fractions for -rpure- vegetation are derived from the model. Comparing with ground measurements, empirical models using soil effect corrected vegetation indices to estimate VWC and dry biomass (DB) are generated. The study enhanced the in-depth understanding of the mechanisms how vegetation growth takes effect on satellites spectral reflectance with and without soil effect, which are particularly useful for modeling in

The Early Growth of the First Black Holes

NASA Astrophysics Data System (ADS)

Johnson, Jarrett L.; Haardt, Francesco

2016-03-01

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur at super-Eddington rates. Finally, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.

Automatic Non-Destructive Growth Measurement of Leafy Vegetables Based on Kinect

PubMed Central

Hu, Yang; Wang, Le; Xiang, Lirong; Wu, Qian; Jiang, Huanyu

2018-01-01

Non-destructive plant growth measurement is essential for plant growth and health research. As a 3D sensor, Kinect v2 has huge potentials in agriculture applications, benefited from its low price and strong robustness. The paper proposes a Kinect-based automatic system for non-destructive growth measurement of leafy vegetables. The system used a turntable to acquire multi-view point clouds of the measured plant. Then a series of suitable algorithms were applied to obtain a fine 3D reconstruction for the plant, while measuring the key growth parameters including relative/absolute height, total/projected leaf area and volume. In experiment, 63 pots of lettuce in different growth stages were measured. The result shows that the Kinect-measured height and projected area have fine linear relationship with reference measurements. While the measured total area and volume both follow power law distributions with reference data. All these data have shown good fitting goodness (R2 = 0.9457–0.9914). In the study of biomass correlations, the Kinect-measured volume was found to have a good power law relationship (R2 = 0.9281) with fresh weight. In addition, the system practicality was validated by performance and robustness analysis. PMID:29518958

[Early childhood growth and development].

PubMed

Arce, Melitón

2015-01-01

This article describes and discusses issues related to the process of childhood growth and development, with emphasis on the early years, a period in which this process reaches critical speed on major structures and functions of the human economy. We reaffirm that this can contribute to the social availability of a generation of increasingly better adults, which in turn will be able to contribute to building a better world and within it a society that enjoys greater prosperity. In the first chapter, we discuss the general considerations on the favorable evolution of human society based on quality of future adults, meaning the accomplishments that today’s children will gain. A second chapter mentions the basics of growth and development in the different fields and the various phenomena that occur in it. In the third we refer to lost opportunities and negative factors that can affect delaying the process and thereby result in not obtaining the expected accomplishments. In the fourth, conclusions and recommendations are presented confirming the initial conception that good early child care serves to build a better society and some recommendations are formulated to make it a good practice.

Fruit and vegetable consumption in adolescence and early adulthood and risk of breast cancer: population based cohort study

PubMed Central

Chen, Wendy Y; Michels, Karin B; Cho, Eunyoung; Willett, Walter C; Eliassen, A Heather

2016-01-01

Objective To evaluate the association between fruit and vegetable intake during adolescence and early adulthood and risk of breast cancer. Design Prospective cohort study. Setting Health professionals in the United States. Participants 90 476 premenopausal women aged 27-44 from the Nurses’ Health Study II who completed a questionnaire on diet in 1991 as well as 44 223 of those women who completed a questionnaire about their diet during adolescence in 1998. Main outcome measure Incident cases of invasive breast cancer, identified through self report and confirmed by pathology report. Results There were 3235 cases of invasive breast cancer during follow-up to 2013. Of these, 1347 cases were among women who completed a questionnaire about their diet during adolescence (ages 13-18). Total fruit consumption during adolescence was associated with a lower risk of breast cancer. The hazard ratio was 0.75 (95% confidence interval 0.62 to 0.90; P=0.01 for trend) for the highest (median intake 2.9 servings/day) versus the lowest (median intake 0.5 serving/day) fifth of intake. The association for fruit intake during adolescence was independent of adult fruit intake. There was no association between risk and total fruit intake in early adulthood and total vegetable intake in either adolescence or early adulthood. Higher early adulthood intake of fruits and vegetables rich in α carotene was associated with lower risk of premenopausal breast cancer. The hazard ratio was 0.82 (0.70 to 0.96) for the highest fifth (median intake 0.5 serving/day) versus the lowest fifth (median intake 0.03 serving/day) intake. The association with adolescent fruit intake was stronger for both estrogen and progesterone receptor negative cancers than estrogen and progesterone receptor positive cancers (P=0.02 for heterogeneity). For individual fruits and vegetables, greater consumption of apple, banana, and grapes during adolescence and oranges and kale during early adulthood was

Comparative proteomic analysis of Populus trichocarpa early stem from primary to secondary growth.

PubMed

Liu, Jinwen; Hai, Guanghui; Wang, Chong; Cao, Shenquan; Xu, Wenjing; Jia, Zhigang; Yang, Chuanping; Wang, Jack P; Dai, Shaojun; Cheng, Yuxiang

2015-08-03

Wood is derived from the secondary growth of tree stems. In this study, we investigated the global changes of protein abundance in Populus early stems using a proteomic approach. Morphological and histochemical analyses revealed three typical stages during Populus early stems, which were the primary growth stage, the transition stage from primary to secondary growth and the secondary growth stage. A total of 231 spots were differentially abundant during various growth stages of Populus early stems. During Populus early stem lignifications, 87 differential spots continuously increased, while 49 spots continuously decreased. These two categories encompass 58.9% of all differential spots, which suggests significant molecular changes from primary to secondary growth. Among 231 spots, 165 unique proteins were identified using LC-ESI-Q-TOF-MS, which were classified into 14 biological function groups. The proteomic characteristics indicated that carbohydrate metabolism, oxido-reduction, protein degradation and secondary cell wall metabolism were the dominantly occurring biochemical processes during Populus early stem development. This study helps in elucidating biochemical processes and identifies potential wood formation-related proteins during tree early stem development. It is a comprehensive proteomic investigation on tree early stem development that, for the first time, reveals the overall molecular networks that occur during Populus early stem lignifications. Copyright © 2015. Published by Elsevier B.V.

Portulaca grandiflora as green roof vegetation: Plant growth and phytoremediation experiments.

PubMed

Vijayaraghavan, K; Arockiaraj, Jesu; Kamala-Kannan, Seralathan

2017-06-03

Finding appropriate rooftop vegetation may improve the quality of runoff from green roofs. Portulaca grandiflora was examined as possible vegetation for green roofs. Green roof substrate was found to have low bulk density (360.7 kg/m 3 ) and high water-holding capacity (49.4%), air-filled porosity (21.1%), and hydraulic conductivity (5270 mm/hour). The optimal substrate also supported the growth of P. grandiflora with biomass multiplication of 450.3% and relative growth rate of 0.038. Phytoextraction potential of P. grandiflora was evaluated using metal-spiked green roof substrate as a function of time and spiked substrate metal concentration. It was identified that P. grandiflora accumulated all metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, and Zn) from metal-spiked green roof substrate. At the end of 40 days, P. grandiflora accumulated 811 ± 26.7, 87.2 ± 3.59, 416 ± 15.8, 459 ± 15.6, 746 ± 20.9, 357 ± 18.5, 565 ± 6.8, and 596 ± 24.4 mg/kg of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. Results also indicated that spiked substrate metal concentration strongly influenced metal accumulation property of P. grandiflora with metal uptake increased and accumulation factor decreased with increase in substrate metal concentration. P. grandiflora also showed potential to translocate all the examined metals with translocation factor greater than 1 for Al, Cu, Fe, and Zn, indicating hyperaccumulation property.

The early growth of the first black holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jarrett L.; Haardt, Francesco

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

The early growth of the first black holes

DOE PAGES

Johnson, Jarrett L.; Haardt, Francesco

2016-03-04

With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

Early stages of zeolite growth

NASA Astrophysics Data System (ADS)

Kumar, Sandeep

Zeolites are crystalline nonporous aluminosilicates with important applications in separation, purification, and adsorption of liquid and gaseous molecules. However, an ability to tailor the zeolite microstructure, such as particle size/shape and pore-size, to make it benign for specific application requires control over nucleation and particle growth processes. But, the nucleation and crystallization mechanisms of zeolites are not fully understood. In this context, the synthesis of an all-silica zeolite with MFI-type framework has been studied extensively as a model system. Throughout chapters 2, 4 and 5, MFI growth process has been investigated by small-angle x-ray scattering (SAXS) and transmission electron microscopy (TEM). Of fundamental importance is the role of nanoparticles (~5 nm), which are present in the precursor sol, in MFI nucleation and crystallization. Formation of amorphous aggregates and their internal restructuring are concluded as essential steps in MFI nucleation. Early stage zeolite particles have disordered and less crystalline regions within, which indicates the role of structurally distributed population of nanoparticles in growth. Faceting occurs after the depletion of nanoparticles. The chapter 6 presents growth studies in silica sols prepared by using a dimer of tertaprpylammonium (TPA) and reports that MFI nucleation and crystallization are delayed with a more pronounced delay in crystal growth.

Characterizing the reproduction number of epidemics with early subexponential growth dynamics

PubMed Central

Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M.

2016-01-01

Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible–infectious–removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

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

PubMed Central

Pound, Matthew J.; Salzmann, Ulrich

2017-01-01

Rapid global cooling at the Eocene – Oligocene Transition (EOT), ~33.9–33.5 Ma, is widely considered to mark the onset of the modern icehouse world. A large and rapid drop in atmospheric pCO2 has been proposed as the driving force behind extinctions in the marine realm and glaciation on Antarctica. However, the global terrestrial response to this cooling is uncertain. Here we present the first global vegetation and terrestrial temperature reconstructions for the EOT. Using an extensive palynological dataset, that has been statistically grouped into palaeo-biomes, we show a more transitional nature of terrestrial climate change by indicating a spatial and temporal heterogeneity of vegetation change at the EOT in both hemispheres. The reconstructed terrestrial temperatures show for many regions a cooling that started well before the EOT and continued into the Early Oligocene. We conclude that the heterogeneous pattern of global vegetation change has been controlled by a combination of multiple forcings, such as tectonics, sea-level fall and long-term decline in greenhouse gas concentrations during the late Eocene to early Oligocene, and does not represent a single response to a rapid decline in atmospheric pCO2 at the EOT. PMID:28233862

Relevance of fruits, vegetables and flavonoids from fruits and vegetables during early life, mid-childhood and adolescence for levels of insulin-like growth factor (IGF-1) and its binding proteins IGFBP-2 and IGFBP-3 in young adulthood.

PubMed

Krupp, Danika; Remer, Thomas; Penczynski, Katharina J; Bolzenius, Katja; Wudy, Stefan A; Buyken, Anette E

2016-02-14

The growth hormone (GH) insulin-like growth factor (IGF) axis has been linked to insulin metabolism and cancer risk. Experimental evidence indicates that the GH-IGF axis itself can be influenced by dietary flavonoids. As fruit and vegetable (FV) intake is a major source of flavonoid consumption, FV's beneficial health effects may be explained via flavonoids' influence on the GH-IGF axis, but observational evidence is currently rare. We used data from Dortmund Nutritional and Anthropometric Longitudinally Designed Study participants to analyse prospective associations between FV, fruit intake and flavonoid intake from FV (FlavFV) with IGF-1 and its binding proteins IGFBP-2 and IGFBP-3. Subjects needed to provide a fasting blood sample in adulthood (18-39 years) and at least two 3-d weighed dietary records in early life (0·5-2 years, n 191), mid-childhood (3-7 years, n 265) or adolescence (girls: 9-15 years, boys: 10-16 years, n 261). Additional analyses were conducted among those providing at least three 24-h urine samples in adolescence (n 236) to address the predictor urinary hippuric acid (HA), a biomarker of polyphenol intake. Higher fruit intake in mid-childhood and adolescence was related to higher IGFBP-2 in adulthood (P=0·03 and P=0·045). Comparable trends (P=0·045-0·09) were discernable for FV intake (but not FlavFV) in all three time windows. Similarly, higher adolescent HA excretion tended to be related (P=0·06) to higher adult IGFBP-2 levels. Regarding IGFBP-3, a marginal (P=0·08) positive association was observed with FlavFV in mid-childhood only. None of the investigated dietary factors was related to IGF-1. In conclusion, higher fruit and FV intakes during growth may be relevant for adult IGFBP-2, but probably not for IGFBP-3 or IGF-1.

An Early Pennsylvanian threshold for the influence of vegetation on fluvial landscapes, based on the geological record of Atlantic Canada

NASA Astrophysics Data System (ADS)

Gibling, Martin; Ielpi, Alessandro; Bashforth, Arden; Davies, Neil

2015-04-01

Vegetation profoundly influences modern fluvial systems, depending on plant life-history strategies, tolerance to disturbance, and habitat drainage. However, direct evidence for these dynamic relationships is cryptic and has commonly been overlooked in ancient deposits. We report evidence for profound interactions between channels, in situ and transported vegetation in Lower Pennsylvanian formations of Atlantic Canada (~310 Ma), attributed to braided, meandering and fixed-channel (anastomosing) systems. Plant groups include lycopsids that preferred stable wetland settings, disturbance-tolerant calamitaleans, and deeply rooted cordaitaleans (early gymnosperms) that originated in the late Mississippian and colonised both wetland and dryland settings. For the meandering and anastomosing channel deposits, upright vegetation was observed within channel-based bedforms and bars and on channel margins. Lycopsids and calamitalean groves colonized the channel bed and bank-attached bars during periods of reduced flow, nucleating bar growth after flow resumed. Upright lycopsids and cordaitaleans are common along channel cutbanks and are locally tilted towards the channel, implying involvement in bank stabilization. Rhizoconcretions that formed around deep cordaitalean roots may have aided bank reinforcement. Tetrapod and arthropod trackways in the channel deposits indicate a close linkage between riparian and aquatic ecosystems. In the braided systems, sediments that contain abundant cordaitalean logs constitute nearly 20% of channel deposits, and the logs form channel-base lags, fill channels up to 6 m deep, and form nuclei for shallow sandbars. Log accumulations overlain by shale lenses imply a contribution to channel avulsion. Rooted channel-sandstones containing upright trees are interpreted as vegetated islands in an island-braided system. Anastomosing systems are abundant in these Lower Pennsylvanian formations but rare in older strata, and the multi-channel island

Winery wastewater inhibits seed germination and vegetative growth of common crop species.

PubMed

Mosse, Kim P M; Patti, Antonio F; Christen, Evan W; Cavagnaro, Timothy R

2010-08-15

The ability to reuse winery wastewater would be of significant benefit to the wine industry, as it could potentially be a cost-effective method of wastewater management, whilst at the same time providing a valuable water resource. This study investigated the effects of different dilutions of a semi-synthetic winery wastewater on the growth and germination of four common crop species in a glasshouse study; barley (Hordeum vulgare), millet (Pennisetum glaucum), lucerne (Medicago sativa) and phalaris (Phalaris aquatica). The wastewater caused a significant delay in the germination of lucerne, millet and phalaris, although overall germination percentage of all species was not affected. Vegetative growth was significantly reduced in all species, with millet being the most severely affected. The germination index of barley correlated very highly (r(2)=0.99) with barley biomass, indicating that barley seed germination bioassays are highly relevant to plant growth, and therefore may be of use as a bioassay for winery wastewater toxicity. Copyright 2010 Elsevier B.V. All rights reserved.

Vegetation extraction from high-resolution satellite imagery using the Normalized Difference Vegetation Index (NDVI)

NASA Astrophysics Data System (ADS)

AlShamsi, Meera R.

2016-10-01

Over the past years, there has been various urban development all over the UAE. Dubai is one of the cities that experienced rapid growth in both development and population. That growth can have a negative effect on the surrounding environment. Hence, there has been a necessity to protect the environment from these fast pace changes. One of the major impacts this growth can have is on vegetation. As technology is evolving day by day, there is a possibility to monitor changes that are happening on different areas in the world using satellite imagery. The data from these imageries can be utilized to identify vegetation in different areas of an image through a process called vegetation detection. Being able to detect and monitor vegetation is very beneficial for municipal planning and management, and environment authorities. Through this, analysts can monitor vegetation growth in various areas and analyze these changes. By utilizing satellite imagery with the necessary data, different types of vegetation can be studied and analyzed, such as parks, farms, and artificial grass in sports fields. In this paper, vegetation features are detected and extracted through SAFIY system (i.e. the Smart Application for Feature extraction and 3D modeling using high resolution satellite ImagerY) by using high-resolution satellite imagery from DubaiSat-2 and DEIMOS-2 satellites, which provide panchromatic images of 1m resolution and spectral bands (red, green, blue and near infrared) of 4m resolution. SAFIY system is a joint collaboration between MBRSC and DEIMOS Space UK. It uses image-processing algorithms to extract different features (roads, water, vegetation, and buildings) to generate vector maps data. The process to extract green areas (vegetation) utilize spectral information (such as, the red and near infrared bands) from the satellite images. These detected vegetation features will be extracted as vector data in SAFIY system and can be updated and edited by end-users, such as

Vegetative and reproductive growth of salt-stressed chickpea are carbon-limited: sucrose infusion at the reproductive stage improves salt tolerance

PubMed Central

Khan, Hammad A.; Siddique, Kadambot H.M.

2017-01-01

Abstract Reproductive processes of chickpea (Cicer arietinum L.) are particularly sensitive to salinity. We tested whether limited photoassimilate availability contributes to reproductive failure in salt-stressed chickpea. Rupali, a salt-sensitive genotype, was grown in aerated nutrient solution, either with non-saline (control) or 30mM NaCl treatment. At flowering, stems were either infused with sucrose solution (0.44M), water only or maintained without any infusion, for 75 d. The sucrose and water infusion treatments of non-saline plants had no effect on growth or yield, but photosynthesis declined in response to sucrose infusion. Salt stress reduced photosynthesis, decreased tissue sugars by 22–47%, and vegetative and reproductive growth were severely impaired. Sucrose infusion of salt-treated plants increased total sugars in stems, leaves and developing pods, to levels similar to those of non-saline plants. In salt-stressed plants, sucrose infusion increased dry mass (2.6-fold), pod numbers (3.8-fold), seed numbers (6.5-fold) and seed yield (10.4-fold), yet vegetative growth and reproductive failure were not rescued completely by sucrose infusion. Sucrose infusion partly rescued reproductive failure in chickpea by increasing vegetative growth enabling more flower production and by providing sucrose for pod and seed growth. We conclude that insufficient assimilate availability limits yield in salt-stressed chickpea. PMID:27140441

A nonlinear coupled soil moisture-vegetation model

NASA Astrophysics Data System (ADS)

Liu, Shikuo; Liu, Shida; Fu, Zuntao; Sun, Lan

2005-06-01

Based on the physical analysis that the soil moisture and vegetation depend mainly on the precipitation and evaporation as well as the growth, decay and consumption of vegetation a nonlinear dynamic coupled system of soil moisture-vegetation is established. Using this model, the stabilities of the steady states of vegetation are analyzed. This paper focuses on the research of the vegetation catastrophe point which represents the transition between aridness and wetness to a great extent. It is shown that the catastrophe point of steady states of vegetation depends mainly on the rainfall P and saturation value v0, which is selected to balance the growth and decay of vegetation. In addition, when the consumption of vegetation remains constant, the analytic solution of the vegetation equation is obtained.

Fruit and vegetable consumption in adolescence and early adulthood and risk of breast cancer: population based cohort study.

PubMed

Farvid, Maryam S; Chen, Wendy Y; Michels, Karin B; Cho, Eunyoung; Willett, Walter C; Eliassen, A Heather

2016-05-11

To evaluate the association between fruit and vegetable intake during adolescence and early adulthood and risk of breast cancer. Prospective cohort study. Health professionals in the United States. 90 476 premenopausal women aged 27-44 from the Nurses' Health Study II who completed a questionnaire on diet in 1991 as well as 44 223 of those women who completed a questionnaire about their diet during adolescence in 1998. Incident cases of invasive breast cancer, identified through self report and confirmed by pathology report. There were 3235 cases of invasive breast cancer during follow-up to 2013. Of these, 1347 cases were among women who completed a questionnaire about their diet during adolescence (ages 13-18). Total fruit consumption during adolescence was associated with a lower risk of breast cancer. The hazard ratio was 0.75 (95% confidence interval 0.62 to 0.90; P=0.01 for trend) for the highest (median intake 2.9 servings/day) versus the lowest (median intake 0.5 serving/day) fifth of intake. The association for fruit intake during adolescence was independent of adult fruit intake. There was no association between risk and total fruit intake in early adulthood and total vegetable intake in either adolescence or early adulthood. Higher early adulthood intake of fruits and vegetables rich in α carotene was associated with lower risk of premenopausal breast cancer. The hazard ratio was 0.82 (0.70 to 0.96) for the highest fifth (median intake 0.5 serving/day) versus the lowest fifth (median intake 0.03 serving/day) intake. The association with adolescent fruit intake was stronger for both estrogen and progesterone receptor negative cancers than estrogen and progesterone receptor positive cancers (P=0.02 for heterogeneity). For individual fruits and vegetables, greater consumption of apple, banana, and grapes during adolescence and oranges and kale during early adulthood was significantly associated with a reduced risk of breast cancer. Fruit juice intake

[Correlations between the characters of the mycelium vegetative growth and the formation of the fruiting body of Ganoderma luciderm].

PubMed

Wang, Shu-fang; He, Xiu-feng; He, Hui-xia; Zhu, Ping

2006-01-01

To select a proper Ganoderma luciderm strain for the fruiting body production. The strains were cultivated on the agar media and in the liquid media, respectively. Then the strains were inoculated onto the solid medium made from agricultural products (such as wheat bran, corn powder, wood meal, etc.) and cultured for a certain period. Strains, which were easier to produce polyporic tissues at the vegetative growth stage, would be more quickly to form fruiting body with high quality and yield of the spores. Appearance of the polyporic tissues at the mycelium vegetative growth stage could be used as a marker for the strain selection for the G. luciderm substituted cultivation.

An assessment of early mandibular growth.

PubMed

Hutchinson, E F; L'Abbé, E N; Oettlé, A C

2012-04-10

Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch

Green Infrastructure Increases Biogeochemical Responsiveness, Vegetation Growth and Decreases Runoff in a Semi-Arid City, Tucson, AZ, USA

NASA Astrophysics Data System (ADS)

Meixner, T.; Papuga, S. A.; Luketich, A. M.; Rockhill, T.; Gallo, E. L.; Anderson, J.; Salgado, L.; Pope, K.; Gupta, N.; Korgaonkar, Y.; Guertin, D. P.

2017-12-01

Green Infrastructure (GI) is often viewed as a mechanism to minimize the effects of urbanization on hydrology, water quality, and other ecosystem services (including the urban heat island). Quantifying the effects of GI requires field measurements of the dimensions of biogeochemical, ecosystem, and hydrologic function that we expect GI to impact. Here we investigated the effect of GI features in Tucson, Arizona which has a low intensity winter precipitation regime and a high intensity summer regime. We focused on understanding the effect of GI on soil hydraulic and biogeochemical properties as well as the effect on vegetation and canopy temperature. Our results demonstrate profound changes in biogeochemical and hydrologic properties and vegetation growth between GI systems and nearby control sites. In terms of hydrologic properties GI soils had increased water holding capacity and hydraulic conductivity. GI soils also have higher total carbon, total nitrogen, and organic matter in general than control soils. Furthermore, we tested the sampled soils (control and GI) for differences in biogeochemical response upon wetting. GI soils had larger respiration responses indicating greater biogeochemical activity overall. Long-term Lidar surveys were used to investigate the differential canopy growth of GI systems versus control sites. The results of this analysis indicate that while a significant amount of time is needed to observe differences in canopy growth GI features due increase tree size and thus likely impact street scale ambient temperatures. Additionally monitoring of transpiration, soil moisture, and canopy temperature demonstrates that GI features increase vegetation growth and transpiration and reduce canopy temperatures. These biogeochemical and ecohydrologic results indicate that GI can increase the biogeochemical processing of soils and increase tree growth and thus reduce urban ambient temperatures.

Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats

PubMed Central

English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H

2013-01-01

In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species. PMID:24340181

Early vegetational changes on a forested wetland constructed for mitigation

USGS Publications Warehouse

Perry, M.C.; Osenton, P.C.; Sibrel, C.B.

1997-01-01

Changes in vegetation were studied on 15 acres of a 35 acre forested wetland created as a mitigation site in Anne Arundel County, Maryland during 1994-96. Meter-square sampling on four different hydrologic elevations determined that grasses initially dominated the area, but decreased from 59 percent in 1994 to 51 percent in 1995 and 30 percent in 1996. Herbaceous non-grass plants (forbs) increased from 19 percent to 56 percent in the three-year period. Area with no plant cover decreased from 21 percent in 1994 to 11 percent in 1995, and 10 percent in 1996. Woody plants comprised 2 percent of the cover in 1994, increased to 4 percent in 1995, and remained at 4 percent in 1996. The increase of woody plants was mainly from natural regeneration (pioneer) plants. Monitoring of the transplanted trees and shrubs indicated 35 percent mortality and little growth of surviving plants. The pioneer woody plant forming most of the cover was black willow (Salix nigra). Differences in the vegetation were observed among the four elevations, although no differences were observed for the major vegetation classes between plots that were planted and those that were not planted with woody plants. Dominant grass species was redtop (Agrostis stolonifera), which comprised 51 percent of the cover in 1994 and 42 percent cover in 1995 and 23 percent in 1996. Other species that were common were bush clover (Lespedeza cuneata), Japanese clover (Lespedeza striata) and flat pea (Lathyrus sylvestris). All four of these dominant species were part of the original seed mixtures that were seeded on the site. A total of 134 species of plants was recorded on the site indicating a fairly diverse community for a newly established habitat.

Effects of goat manure liquid fertilizer combined with AB-MIX on foliage vegetables growth in hydroponic

NASA Astrophysics Data System (ADS)

Sunaryo, Y.; Purnomo, D.; Darini, M. T.; Cahyani, V. R.

2018-03-01

Hydroponic as one of the protected cultivation practices is very important to be developed in Indonesia due to not only the reduction of arable agricultural lands in lines with increasing of residential demand and other public facilities but also due to the negative influences of climate change as well global warming to plant growth. The effects of liquid fertilizer made from goat manure (LFGM) in combination with AB-Mix on three kinds of foliage vegetable growth was examined in hydroponics. The research was conducted by 3 x 4 factorial experiment and arranged in Completely Randomized Design with 3 replications. The first factor was foliage vegetable consisting of 3 levels: Mustard Green, Lettuce, and Red Spinach. The second factor was the mixture composition of nutrient solution consisting of 4 levels: LFGM + AB-Mix (v/v: 1:1), LFGM + AB-Mix (v/v: 1:3), LFGM + AB-Mix (v/v: 3:1), and A/B mix as control. Results indicated that the application of LFGM + AB-Mix (v/v: 1:3) resulted in similar plant growth as control (AB-Mix application), and also resulted in the highest chlorophyll content of Mustard green.

[Variability of vegetation growth season in different latitudinal zones of North China: a monitoring by NOAA NDVI and MSAVI].

PubMed

Wang, Hong; Li, Xiaobing; Han, Ruibo; Ge, Yongqin

2006-12-01

In this study, North China was latitudinally divided into five zones, i.e., 32 degrees - 36 degrees N (Zone I), 36 degrees - 40 degrees N (Zone II), 40 degrees - 44 degrees N (Zone III), 44 degrees - 48 degrees N (Zone IV) and 48 degrees - 52 degrees N (Zone V), and the NOAA/ AVHRR NDVI and MSAVI time-series images from 1982 to 1999 were smoothed with Savitzky-Golay filter algorithm. Based on the EOF analysis, the principal components of NDVI and MSAVI for the vegetations in different latitudinal zones of North China were extracted, the annual beginning and ending dates and the length of growth season in 1982 - 1999 were estimated, and the related parameters were linearly fitted, aimed to analyze the variability of vegetation growth season. The results showed that the beginning date of the growth season in different zones tended to be advanced, while the ending date tended to be postponed with increasing latitude. The length of the growth season was also prolonged, with the prolonging time exceeded 10 days.

Time-delay-induced dynamical behaviors for an ecological vegetation growth system driven by cross-correlated multiplicative and additive noises.

PubMed

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.

Modeling of the Competitive Growth of Listeria monocytogenes and Lactococcus lactis in Vegetable Broth

PubMed Central

Breidt, Frederick; Fleming, Henry P.

1998-01-01

Current mathematical models used by food microbiologists do not address the issue of competitive growth in mixed cultures of bacteria. We developed a mathematical model which consists of a system of nonlinear differential equations describing the growth of competing bacterial cell cultures. In this model, bacterial cell growth is limited by the accumulation of protonated lactic acid and decreasing pH. In our experimental system, pure and mixed cultures of Lactococcus lactis and Listeria monocytogenes were grown in a vegetable broth medium. Predictions of the model indicate that pH is the primary factor that limits the growth of L. monocytogenes in competition with a strain of L. lactis which does not produce the bacteriocin nisin. The model also predicts the values of parameters that affect the growth and death of the competing populations. Further development of this model will incorporate the effects of additional inhibitors, such as bacteriocins, and may aid in the selection of lactic acid bacterium cultures for use in competitive inhibition of pathogens in minimally processed foods. PMID:9726854

Effects of vegetation, corridor width and regional land use on early successional birds on powerline corridors.

PubMed

Askins, Robert A; Folsom-O'Keefe, Corrine M; Hardy, Margaret C

2012-01-01

Powerline rights-of-way (ROWs) often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor) and field sparrow (Spizella pusilla) were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater) occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management.

Effects of Vegetation, Corridor Width and Regional Land Use on Early Successional Birds on Powerline Corridors

PubMed Central

Askins, Robert A.; Folsom-O'Keefe, Corrine M.; Hardy, Margaret C.

2012-01-01

Powerline rights-of-way (ROWs) often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor) and field sparrow (Spizella pusilla) were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater) occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management. PMID:22363660

Take me to your leader: does early successional nonhost vegetation spatially inhibit Pissodes strobi (Coleoptera: Curculionidae)?

PubMed

Koopmans, Jordan M; De La Giroday, Honey-Marie C; Lindgren, B Staffan; Aukema, Brian H

2009-08-01

The spatial influences of host and nonhost trees and shrubs on the colonization patterns of white pine weevil Pissodes strobi (Peck) were studied within a stand of planted interior hybrid spruce [Picea glauca (Moench) Voss x Picea engelmannii (Parry) ex Engelm.]. Planted spruce accounted for one third of all trees within the stand, whereas the remaining two thirds were comprised of early-successional nonhost vegetation, such as alder (Alnus spp.), paper birch (Betula papyrifera Marsh.), black cottonwood [Populus balsamifera ssp. trichocarpa (T. Ng.) Brayshaw], lodgepole pine [Pinus contorta (Dougl.) ex Loud.], trembling aspen (Populus tremuloides Michx), willow (Salix spp.), and Canadian buffaloberry [Shepherdia canadensis (L.) Nutt.]. Unlike the spruce trees, nonhost vegetation in the stand was not uniformly distributed. Spatial point process models showed that Canadian buffaloberry, paper birch, black cottonwoood, and trembling aspen had negative associations with damage caused by the weevil, even though the density of the insects' hosts in these areas did not change. Moreover, knowing the locations of these nonhost trees provided as much, or more, inference about the locations of weevil-attacked trees as knowing the locations of suitable or preferred host trees (i.e., those larger in size). Nonhost volatiles, the alteration of soil composition, and overstory shade are discussed as potential explanatory factors for the patterns observed. New research avenues are suggested to determine whether nonhost vegetation in early successional stands might be an additional tool in the management of these insects in commercially important forests.

Effects of intensive management practices on 10-year Douglas-fir growth, soil nutrient pools, and vegetation communities in the Pacific Northwest, USA

Treesearch

Robert A. Slesak; Timothy B. Harrington; Dave Peter; Daniel G. DeBruler; Stephen H. Schoenholtz; Brian D. Strahm

2016-01-01

Intensive management practices are commonly used to increase fiber production from forests, but potential tradeoffs with maintenance of long-term productivity and early successional biodiversity have yet to be quantified. We assessed soil and vegetation responses in replicated manipulations of logging debris (LD; either retained or removed) and competing vegetation...

Role of burning season on initial understory vegetation response to prescribed fire in a mixed conifer forest

USGS Publications Warehouse

Knapp, E.E.; Schwilk, D.W.; Kane, J.M.; Keeley, J.E.

2007-01-01

Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this study was to determine if burn season influences postfire vegetation recovery. Replicated early-season burn, late-season burn, and unburned control units were established in a mixed conifer forest, and understory vegetation was evaluated before and after treatment. Vegetation generally recovered rapidly after prescribed burning. However, late-season burns resulted in a temporary but significant drop in cover and a decline in species richness at the 1 m 2 scale in the following year. For two of the several taxa that were negatively affected by burning, the reduction in frequency was greater after late-season than early-season burns. Early-season burns may have moderated the effect of fire by consuming less fuel and lessening the amount of soil heating. Our results suggest that, when burned under high fuel loading conditions, many plant species respond more strongly to differences in fire intensity and severity than to timing of the burn relative to stage of plant growth. ?? 2007 NRC.

Discrimination of growth and water stress in wheat by various vegetation indices through a clear a turbid atmosphere

NASA Technical Reports Server (NTRS)

Jackson, R. D.; Slater, P. M.; Pinter, P. J. (Principal Investigator)

1982-01-01

Reflectance data were obtained over a drought-stressed and a well-watered wheat plot with a hand-held radiometer having bands similar to the MSS bands of the LANDSAT satellites. Data for 48 clear days were interpolated to yield reflectance values for each day of the growing season, from planting until harvest. With an atmospheric path radiance model and LANDSAT-2 calibration data, the reflectance were used to simulate LANDSAT digital counts (not quantized) for the four LANDSAT bands for each day of the growing season, through a clear (approximately 100 km meteorological range) and a turbid (approximately 10 km meteorological range) atmosphere. Several ratios and linear combinations of bands were calculated using the simulated data, then assessed for their relative ability to discriminate vegetative growth and plant stress through the two atmospheres. The results show that water stress was not detected by any of the indices until after growth was retarded, and the sensitivity of the various indices to vegetation depended on plant growth stage and atmospheric path radiance.

Annual Growth of Contract Costs for Major Programs in Development and Early Production

DTIC Science & Technology

2016-03-21

changes, we can identify some underlying drivers and rule out others. Development and Early Production Differences BBP-era drops are driven by dropping...Annual Growth of Contract Costs for Major Programs in Development and Early Production Dan Davis and Philip S...Growth of Contract Costs for Major Programs in Development and Early Production Dan Davis and Philip S. Antón March 21, 2016 SUMMARY Cost is

The Not-so-Dark Ages: ecology for human growth in medieval and early twentieth century Portugal as inferred from skeletal growth profiles.

PubMed

Cardoso, Hugo F V; Garcia, Susana

2009-02-01

This study attempts to address the issue of relative living standards in Portuguese medieval and early 20th century periods. Since the growth of children provides a good measure of environmental quality for the overall population, the skeletal growth profiles of medieval Leiria and early 20th century Lisbon were compared. Results show that growth in femur length of medieval children did not differ significantly from that of early 20th century children, but after puberty medieval adolescents seem to have recovered, as they have significantly longer femora as adults. This is suggestive of greater potential for catch-up growth in medieval adolescents. We suggest that this results from distinct child labor practices, which impact differentially on the growth of Leiria and Lisbon adolescents. Work for medieval children and adolescents were related to family activities, and care and attention were provided by family members. Conversely, in early 20th century Lisbon children were more often sent to factories at around 12 years of age as an extra source of family income, where they were exploited for their labor. Since medieval and early 20th century children were stunted at an early age, greater potential for catch-up growth in medieval adolescents results from exhausting work being added to modern adolescent's burdens of disease and poor diet, when they entered the labor market. Although early 20th century Lisbon did not differ in overall unfavorable living conditions from medieval Leiria, after puberty different child labor practices may have placed modern adolescents at greater risk of undernutrition and poor growth. 2008 Wiley-Liss, Inc.

Vegetation response to the 2016-2017 extreme Sierra Nevada snowfall event using multitemporal terrestrial laser scanning: initial results

NASA Astrophysics Data System (ADS)

Greenberg, J. A.; Hou, Z.; Ramirez, C.; Hart, R.; Marchi, N.; Parra, A. S.; Gutierrez, B.; Tompkins, R.; Harpold, A.; Sullivan, B. W.; Weisberg, P.

2017-12-01

The Sierra Nevada Mountains experienced record-breaking snowfall during the 2016-2017 winter after a prolonged period of drought. We hypothesized that at lower elevations, the increased snowmelt would result in a significant increase in biomass across vegetation strata, but at higher elevations, the snowpack would result in a diminished growing season, and yield a suppression of growth rates particularly in the understory vegetation. To test these hypotheses, we sampled sites across the Plumas National Forest and Lake Tahoe Basin using a terrestrial laser scanner (TLS) in the early growing season, and then rescanned these sites in the late growing season. Herein, we present initial, early results from this analysis, focusing on the biomass and height changes in trees.

Chitinases are essential for sexual development but not vegetative growth in Cryptococcus neoformans.

PubMed

Baker, Lorina G; Specht, Charles A; Lodge, Jennifer K

2009-11-01

Cryptococcus neoformans is an opportunistic pathogen that mainly infects immunocompromised individuals. The fungal cell wall of C. neoformans is an excellent target for antifungal therapies since it is an essential organelle that provides cell structure and integrity. Importantly, it is needed for localization or attachment of known virulence factors, including melanin, phospholipase, and the polysaccharide capsule. The polysaccharide fraction of the cryptococcal cell wall is a complex structure composed of chitin, chitosan, and glucans. Chitin is an indispensable component of many fungal cell walls that contributes significantly to cell wall strength and integrity. Fungal cell walls are very dynamic, constantly changing during cell division and morphogenesis. Hydrolytic enzymes, such as chitinases, have been implicated in the maintenance of cell wall plasticity and separation of the mother and daughter cells at the bud neck during vegetative growth in yeast. In C. neoformans we identified four predicted endochitinases, CHI2, CHI21, CHI22, and CHI4, and a predicted exochitinase, hexosaminidase, HEX1. Enzymatic analysis indicated that Chi2, Chi22, and Hex1 actively degraded chitinoligomeric substrates. Chi2 and Hex1 activity was associated mostly with the cellular fraction, and Chi22 activity was more prominent in the supernatant. The enzymatic activity of Hex1 increased when grown in media containing only N-acetylglucosamine as a carbon source, suggesting that its activity may be inducible by chitin degradation products. Using a quadruple endochitinase deletion strain, we determined that the endochitinases do not affect the growth or morphology of C. neoformans during asexual reproduction. However, mating assays indicated that Chi2, Chi21, and Chi4 are each involved in sexual reproduction. In summary, the endochitinases were found to be dispensable for routine vegetative growth but not sexual reproduction.

Does the silver moss Bryum argenteum exhibit sex-specific patterns in vegetative growth rate, asexual fitness or prezygotic reproductive investment?

PubMed

Horsley, Kimberly; Stark, Lloyd R; McLetchie, D Nicholas

2011-05-01

Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is

Does the silver moss Bryum argenteum exhibit sex-specific patterns in vegetative growth rate, asexual fitness or prezygotic reproductive investment?

PubMed Central

Horsley, Kimberly; Stark, Lloyd R.; McLetchie, D. Nicholas

2011-01-01

Background and Aims Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Methods Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. Key Results The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Conclusions Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and

[Effects of postnatal growth retardation on early neurodevelopment in premature infants with intrauterine growth retardation].

PubMed

Cai, Yue-Ju; Song, Yan-Yan; Huang, Zhi-Jian; Li, Jian; Qi, Jun-Ye; Xiao, Xu-Wen; Wang, Lan-Xiu

2015-09-01

To study the effects of postnatal growth retardation on early neurodevelopment in premature infants with intrauterine growth retardation (IUGR). A retrospective analysis was performed on the clinical data of 171 premature infants who were born between May 2008 and May 2012 and were followed up until a corrected gestational age of 6 months. These infants were classified into two groups: IUGR group (n=40) and appropriate for gestational age (AGA) group (n=131). The growth retardation rates at the corrected gestational ages of 40 weeks, 3 months, and 6 months, as well as the neurodevelopmental outcome (evaluated by Gesell Developmental Scale) at corrected gestational ages of 3 and 6 months, were compared between the two groups. The growth retardation rate in the IUGR group was significantly higher than in the AGA group at the corrected gestational ages of 40 weeks, 3 months, and 6 months. All five developmental quotients evaluated by Gesell Developmental Scale (gross motor, fine motor, language, adaptability and individuality) in the IUGR group were significantly lower than in the AGA group at the corrected gestational ages of 3 months. At the corrected gestational age of 6 months, the developmental quotients of fine motor and language in the IUGR group were significantly lower than in the AGA group, however, there were no significant differences in the developmental quotients of gross motor, adaptability and individuality between the two groups. All five developmental quotients in IUGR infants with catch-up lag in weight were significantly lower than in IUGR and AGA infants who had caught up well. Growth retardation at early postnatal stages may adversely affect the early neurodevelopment in infants with IUGR.

Ethylene production throughout growth and development of plants

NASA Technical Reports Server (NTRS)

Wheeler, Raymond M.; Peterson, Barbara V.; Stutte, Gary W.

2004-01-01

Ethylene production by 10 or 20 m2 stands of wheat, soybean, lettuce, potato, and tomato was monitored throughout growth and development in an atmospherically closed plant chamber. Chamber ethylene levels varied among species and rose during periods of canopy expansion and rapid growth for all species. Following this, ethylene levels either declined during seed fill and maturation for wheat and soybean, or remained relatively constant for potato and tomato (during flowering and early fruit development). Lettuce plants were harvested during rapid growth and peak ethylene production. Chamber ethylene levels increased rapidly during tomato ripening, reaching concentrations about 10 times that measured during vegetative growth. The highest ethylene production rates during vegetative growth ranged from 1.6 to 2.5 nmol m-2 d-1 during rapid growth of lettuce and wheat stands, or about 0.3 to 0.5 nmol g-1 fresh weight per hour. Estimates of stand ethylene production during tomato ripening showed that rates reached 43 nmol m-2 d-1 in one study and 93 nmol m-2 d-1 in a second study with higher lighting, or about 50x that of the rate during vegetative growth of tomato. In a related test with potato, the photoperiod was extended from 12 to 24 hours (continuous light) at 58 days after planting (to increase tuber yield), but this change in the environment caused a sharp increase in ethylene production from the basal rate of 0.4 to 6.2 nmol m-2 d-1. Following this, the photoperiod was changed back to 12 h at 61 days and ethylene levels decreased. The results suggest three separate categories of ethylene production were observed with whole stands of plants: 1) production during rapid vegetative growth, 2) production during climacteric fruit ripening, and 3) production from environmental stress.

Early growth patterns are associated with intelligence quotient scores in children born small-for-gestational age.

PubMed

Varella, Marcia H; Moss, William J

2015-08-01

To assess whether patterns of growth trajectory during infancy are associated with intelligence quotient (IQ) scores at 4 years of age in children born small-for-gestational age (SGA). Children in the Collaborative Perinatal Project born SGA were eligible for analysis. The primary outcome was the Stanford-Binet IQ score at 4 years of age. Growth patterns were defined based on changes in weight-for-age z-scores from birth to 4 months and 4 to 12 months of age and consisted of steady, early catch-up, late catch-up, constant catch-up, early catch-down, late catch-down, constant catch-down, early catch-up & late catch-down, and early catch-down & late catch-up. Multivariate linear regression was used to assess associations between patterns of growth and IQ. We evaluated patterns of growth and IQ in 5640 children. Compared with children with steady growth, IQ scores were 2.9 [standard deviation (SD)=0.54], 1.5 (SD=0.63), and 2.2 (SD=0.9) higher in children with early catch-up, early catch-up and later catch-down, and constant catch-up growth patterns, respectively, and 4.4 (SD=1.4) and 3.9 (SD=1.5) lower in children with early catch-down & late catch-up, and early catch-down growth patterns, respectively. Patterns in weight gain before 4 months of age were associated with differences in IQ scores at 4 years of age, with children with early catch-up having slightly higher IQ scores than children with steady growth and children with early catch-down having slightly lower IQ scores. These findings have implications for early infant nutrition in children born SGA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

DYZ1 copy number variation, Y chromosome polymorphism and early recurrent spontaneous abortion/early embryo growth arrest.

PubMed

Yan, Junhao; Fan, Lingling; Zhao, Yueran; You, Li; Wang, Laicheng; Zhao, Han; Li, Yuan; Chen, Zi-Jiang

2011-12-01

To find the association between recurrent spontaneous abortion (RSA)/early embryo growth arrest and Y chromosome polymorphism. Peripheral blood samples of the male patients of big Y chromosome, small Y chromosome and other male patients whose partners suffered from unexplained RSA/early embryo growth arrest were collected. PCR and real-time fluorescent quantitative PCR were used to test the deletion and the copy number variation of DYZ1 region in Y chromosome of the patients. A total of 79 big Y chromosome patients (48 of whose partners suffered from RSA or early embryo growth arrest), 7 small Y chromosome patients, 106 other male patients whose partners had suffered from unexplained RSA or early embryo growth arrest, and 100 normal male controls were enrolled. There was no fraction deletion of DYZ1 detected both in big Y patients and in normal men. Of RSA patients, 1 case showed deletion of 266bp from the gene locus 25-290bp, and 2 cases showed deletion of 773bp from 1347 to 2119bp. Of only 7 small Y chromosome patients, 2 cases showed deletion of 266bp from 25 to 290bp, and 4 cases showed deletion of 773bp from 1347 to 2119bp and 275bp from 3128 to 3420bp. The mean of DYZ1 copies was 3900 in normal control men; the mean in big Y patients was 5571, in RSA patients was 2655, and in small Y patients was 1059. All of the others were significantly different (P<0.01) compared with normal control men, which meant that DYZ1 copy number in normal control men was less than that of big Y chromosome patients, and was more than that of unexplained early RSA patients and small Y patients. The integrity and copy number variation of DYZ1 are closely related to the Y chromosome length under microscope. The cause of RSA/early embryo growth arrest in some couples may be the increase (big Y patients) or decrease of DYZ1 copy number in the husbands' Y chromosome. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Response of timber growth and avian communities to quality vegetation management in mid-rotation crp pine plantations

Treesearch

Brandon G. Sladek; Ian A. Munn; L. Wes Burder; Scott D. Roberts

2006-01-01

Provisions of the 2002 Farm Bill gave Conservation Reserve Program (CRP) participants greater flexibility to implement mid-contract management activities that encourage wildlife habitat improvement and timber production. Quality Vegetation Management (QVM) is one such technique that utilizes the selective herbicide Imazapyr and prescribed burning. Timber growth (d.b.h...

Overexpression of a truncated CTF7 construct leads to pleiotropic defects in reproduction and vegetative growth in Arabidopsis.

PubMed

Liu, Desheng; Makaroff, Christopher A

2015-03-05

Eco1/Ctf7 is essential for the establishment of sister chromatid cohesion during S phase of the cell cycle. Inactivation of Ctf7/Eco1 leads to a lethal phenotype in most organisms. Altering Eco1/Ctf7 levels or point mutations in the gene can lead to alterations in nuclear division as well as a wide range of developmental defects. Inactivation of Arabidopsis CTF7 (AtCTF7) results in severe defects in reproduction and vegetative growth. To further investigate the function(s) of AtCTF7, a tagged version of AtCTF7 and several AtCTF7 deletion constructs were created and transformed into wild type or ctf7 +/- plants. Transgenic plants expressing 35S:NTAP:AtCTF7∆299-345 (AtCTF7∆B) displayed a wide range of phenotypic alterations in reproduction and vegetative growth. Male meiocytes exhibited chromosome fragmentation and uneven chromosome segregation. Mutant ovules contained abnormal megasporocyte-like cells during pre-meiosis, megaspores experienced elongated meiosis and megagametogenesis, and defective megaspores/embryo sacs were produced at various stages. The transgenic plants also exhibited a broad range of vegetative defects, including meristem disruption and dwarfism that were inherited in a non-Mendelian fashion. Transcripts for epigenetically regulated transposable elements (TEs) were elevated in transgenic plants. Transgenic plants expressing 35S:AtCTF7∆B displayed similar vegetative defects, suggesting the defects in 35S:NTAP:AtCTF7∆B plants are caused by high-level expression of AtCTF7∆B. High level expression of AtCTF7∆B disrupts megasporogenesis, megagametogenesis and male meiosis, as well as causing a broad range of vegetative defects, including dwarfism that are inherited in a non-Mendelian fashion.

A case of functional growth hormone deficiency and early growth retardation in a child with IFT172 mutations.

PubMed

Lucas-Herald, Angela K; Kinning, Esther; Iida, Aritoshi; Wang, Zheng; Miyake, Noriko; Ikegawa, Shiro; McNeilly, Jane; Ahmed, S Faisal

2015-04-01

Ciliopathies are a group of rare conditions that present through a wide range of manifestations. Given the relative common occurrence of defects of the GH/IGF-I axis in children with short stature and growth retardation, the association between ciliopathies and these defects needs further attention. Our patient is a boy who was born at term and noted to have early growth retardation and weight gain within the first 18 months of life. Biochemical tests demonstrated low IGF-I but a normal peak GH on stimulation and an adequate increase in IGF-I on administration of recombinant human growth hormone (rhGH). A magnetic resonance imaging scan revealed pituitary hypoplasia and an ectopic posterior pituitary. His growth responded well to rhGH therapy. Subsequently he also developed a retinopathy of his rods and cones, metaphyseal dysplasia, and hypertension with renal failure requiring renal replacement therapy. Whole-exome sequencing demonstrated compound heterozygous mutations of IFT172, thus consistent with a ciliopathy. This is the first reported case of a child with a mutation in IFT172 who presented with growth retardation in early childhood and was initially managed as a case of functional GH deficiency that responded to rhGH therapy. This case highlights the importance of ciliary function in pituitary development and the link between early onset growth failure and ciliopathies.

Studying Individual Plant AOX Gene Functionality in Early Growth Regulation: A New Approach.

PubMed

Arnholdt-Schmitt, Birgit; Patil, Vinod Kumar

2017-01-01

AOX1 and AOX2 genes are thought to play different physiological roles. Whereas AOX1 is typically expected to associate to stress and growth responses, AOX2 was more often found to be linked to development and housekeeping functions. However, this view is questioned by several adverse observations. For example, co-regulated expression for DcAOX1 and DcAOX2a genes was recently reported during growth induction in carrot (Daucus carota L.). Early expression peaks for both genes during the lag phase of growth coincided with a critical time point for biomass prediction, a result achieved by applying calorespirometry. The effect of both AOX family member genes cannot easily be separated. However, separate functional analysis is required in order to identify important gene-specific polymorphisms or patterns of polymorphisms for functional marker development and its use in breeding. Specifically, a methodology is missing that enables studying functional effects of individual genes or polymorphisms/polymorphic patterns on early growth regulation.This protocol aims to provide the means for identifying plant alternative oxidase (AOX) gene variants as functional markers for early growth regulation. Prerequisite for applying this protocol is available Schizosaccharomyces pombe strains that were transformed with individual AOX genes following published protocols from Anthony Moore's group (Albury et al., J Biol Chem 271:17062-17066, 1996; Affourtit et al., J Biol Chem 274:6212-6218, 1999). The novelty of the present protocol comes by modifying yeast cell densities in a way that allows studying critical qualitative and quantitative effects of AOX gene variants (isoenzymes or polymorphic genes) during the early phase of growth. Calorimetry is used as a novel tool to confirm differences obtained by optical density measurements in early growth regulation by metabolic phenotyping (released heat rates). This protocol enables discriminating between AOX genes that inhibit growth and

Early Holocene vegetation - climate interactions in the central part of European Russia

NASA Astrophysics Data System (ADS)

Novenko, Elena; Olchev, Alexander

2017-04-01

The new Early Holocene vegetation and climate reconstruction (approximately 10100 -7800 cal. yr. BP) for the forest zone the central European Russia are based on pollen records from three key regions located in taiga, mixed coniferous-broadleaved and broadleaved forest zones. The climatic parameters (the mean annual temperature and precipitation) and total forest coverage during the early Holocene were reconstructed using the Best Modern Analogue technique. Information about moistening conditions was revealed from reconstructions of actual evapotranspiration (ET) and potential evaporation (PET). For calculation of the annual ET and PET rates of the forest landscapes a regression model was applied. The model is based on nonlinear approximations of annual values of ET and PET provided by the Levenberg-Marquardt method using the results of numerical simulations of ET and PET carried out by a Mixfor-SVAT model for the forests with different species compositions under various thermal and moistening conditions. Mixfor-SVAT is an one-dimensional model of the energy, H2O and CO2 exchange between vertically structured mono- and multi-specific forest stands and the atmosphere (Olchev et al., 2002). Obtained results showed that the considered period was characterized by relatively low air temperatures and high precipitation compared with modern conditions. Analysis of the long-term pattern of the mean annual temperature for all three regions reveal two synchronous significant cooling periods observed in 9100-9300 cal. yr. BP and 8100-8500 cal. yr. BP as well as rapid growth of the air temperature in 8100-7800 cal. yr. BP, when the annual temperatures increased by 3°C during about 300 years. The cooling phase of 8100-8500 cal. yr. BP could be corresponded to the distinct "8.2 ka event" widely recorded across Europe. Periods of climate warming are coincided with periods of precipitation rise whereas the cool phases are characterized by its decrease. The lowest ET and PET rates

Instability mechanisms and early warning indicators for mesophilic anaerobic digestion of vegetable waste.

PubMed

Li, Dong; Chen, Lin; Liu, Xiaofeng; Mei, Zili; Ren, Haiwei; Cao, Qin; Yan, Zhiying

2017-12-01

In order to elucidate the instability mechanism, screen early warning indicators, and propose control measures, the mesophilic digestion of vegetable waste (VW) was carried out at organic loading rates (OLR) of 0.5, 1.0, and 1.5g volatile solid (VS)/(Ld). The process parameters, including biogas components, volatile fatty acids (VFA), ammonia, pH, total alkalinity (TA), bicarbonate alkalinity (BA), and intermediate alkalinity (IA), were monitored every day. Digestion was inhibited at OLR of 1.5gVS/(Ld). The primary causes of instability are a high sugar and negligible ammonia content, in addition to the feed without effluent recirculation, which led to BA loss. The ratios of CH 4 /CO 2 , VFA/BA, propionate, n-butyrate and iso-valerate were selected as early warning indicators. In order to maintain the digestion of VW at a high OLR, control measures including effluent recirculation and trace element addition are recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early treatment with metformin induces resistance against tumor growth in adult rats

PubMed Central

Trombini, Amanda B; Franco, Claudinéia CS; Miranda, Rosiane A; de Oliveira, Júlio C; Barella, Luiz F; Prates, Kelly V; de Souza, Aline A; Pavanello, Audrei; Malta, Ananda; Almeida, Douglas L; Tófolo, Laize P; Rigo, Kesia P; Ribeiro, Tatiane AS; Fabricio, Gabriel S; de Sant’Anna, Juliane R; Castro-Prado, Marialba AA; de Souza, Helenir Medri; de Morais, Hely; Mathias, Paulo CF

2015-01-01

It is known that antidiabetic drug metformin, which is used worldwide, has anti-cancer effects and can be used to prevent cancer growth. We tested the hypothesis that tumor cell growth can be inhibited by early treatment with metformin. For this purpose, adult rats chronically treated with metformin in adolescence or in adulthood were inoculated with Walker 256 carcinoma cells. Adult rats that were treated with metformin during adolescence presented inhibition of tumor growth, and animals that were treated during adult life did not demonstrate any changes in tumor growth. Although we do not have data to disclose a molecular mechanism to the preventive metformin effect, we present, for the first time, results showing that cancer growth in adult life is dependent on early life intervention, thus supporting a new therapeutic prevention for cancer. PMID:26024008

Basic fibroblast growth factor promotes the development of human ovarian early follicles during growth in vitro.

PubMed

Wang, Tian-ren; Yan, Li-ying; Yan, Jie; Lu, Cui-ling; Xia, Xi; Yin, Tai-lang; Zhu, Xiao-hui; Gao, Jiang-man; Ding, Ting; Hu, Wei-hong; Guo, Hong-yan; Li, Rong; Qiao, Jie

2014-03-01

What is the effect of basic fibroblast growth factor (bFGF) on the growth of individual early human follicles in a three-dimensional (3D) culture system in vitro? The addition of 200 ng bFGF/ml improves human early follicle growth, survival and viability during growth in vitro. It has been demonstrated that bFGF enhances primordial follicle development in human ovarian tissue culture. However, the growth and survival of individual early follicles in encapsulated 3D culture have not been reported. The maturation in vitro of human ovarian follicles was investigated. Ovarian tissue (n= 11) was obtained from 11 women during laparoscopic surgery for gynecological disease, after obtaining written informed consent. One hundred and fifty-four early follicles were isolated by enzymic digestion and mechanical disruption. They were individually encapsulated into alginate (1% w/v) and randomly assigned to be cultured with 0, 100, 200 or 300 ng bFGF/ml for 8 days. Individual follicles were cultured in minimum essential medium α (αMEM) supplemented with bFGF. Follicle survival and growth were assessed by microscopy. Follicle viability was evaluated under confocal laser scanning microscope following Calcein-AM and Ethidium homodimer-I (Ca-AM/EthD-I) staining. After 8 days in culture, all 154 follicles had increased in size. The diameter and survival rate of the follicles and the percentage with good viability were significantly higher in the group cultured with 200 ng bFGF/ml than in the group without bFGF (P < 0.05). The percentage of follicles in the pre-antral stage was significantly higher in the 200 ng bFGF/ml group than in the group without bFGF (P < 0.05), while the percentages of primordial and primary follicles were significantly lower (P < 0.05). The study focuses on the effect of bFGF on the development of individual human early follicles in 3D culture in vitro and has limited ability to reveal the specific effect of bFGF at each different stage. The findings

Quantifying the effects of land use and climate on Holocene vegetation in Europe

NASA Astrophysics Data System (ADS)

Marquer, Laurent; Gaillard, Marie-José; Sugita, Shinya; Poska, Anneli; Trondman, Anna-Kari; Mazier, Florence; Nielsen, Anne Birgitte; Fyfe, Ralph M.; Jönsson, Anna Maria; Smith, Benjamin; Kaplan, Jed O.; Alenius, Teija; Birks, H. John B.; Bjune, Anne E.; Christiansen, Jörg; Dodson, John; Edwards, Kevin J.; Giesecke, Thomas; Herzschuh, Ulrike; Kangur, Mihkel; Koff, Tiiu; Latałowa, Małgorzata; Lechterbeck, Jutta; Olofsson, Jörgen; Seppä, Heikki

2017-09-01

Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen-based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming

Vegetated Riprap Installation Techniques for Steambank Protection, Fish and Wildlife Habitat Creation

NASA Astrophysics Data System (ADS)

Raymond, Pierre

2014-05-01

the past seven years to the stream banks of eleven different sites on large and medium sized rivers in three Provinces of Canada. To date, the survival and growth of vegetated riprap brush layers installed along riverbanks has been assessed as good to excellent, resulting in the substantial creation of fish, wildlife and urban habitat. The survival and growth, along with early results of an excavation trial, will be presented.

Photosynthetic response, survival, and growth of three ponderosa pine stocktypes under water stress enhanced by vegetative competition

Treesearch

Jeremiah R. Pinto; John D. Marshall; R. Kasten Dumroese; Anthony S. Davis; Douglas R. Cobos

2012-01-01

Selecting the proper stock type for reforestation on dry sites can be critical for the long-term survival and growth of seedlings. In this study, we use a novel approach to understand stock type selection on a site where drought was induced with vegetative competition. Three ponderosa pine (Pinus ponderosa Lawson & C. Lawson var. ponderosa C. Lawson) seedling stock...

An invasive plant alters phenotypic selection on the vegetative growth of a native congener.

PubMed

Beans, Carolyn M; Roach, Deborah A

2015-02-01

The ecological consequences of plant competition have frequently been tested, but the evolutionary outcomes of these interactions have gone largely unexplored. The study of species invasions can make an important contribution to this field of research by allowing us to watch ecological and evolutionary processes unfold as a novel species is integrated into a plant community. We explored the ecological and evolutionary impact of an invasive jewelweed, Impatiens glandulifera, on a closely related native congener, I. capensis and asked: (1) Does the presence of the invasive jewelweed alter the fitness of native jewelweed populations? (2) Does the invasive jewelweed affect the vegetative growth of the native congener? and (3) Does the invasive jewelweed alter phenotypic selection on the vegetative traits of the native congener? We used a greenhouse competition experiment, an invasive species removal field experiment, and a survey of natural populations. We show that when the invasive jewelweed is present, phenotypic selection favors native jewelweed individuals investing less in rapid upward growth and more in branching and fruiting potential through the production of nodes. This research demonstrates that invasive plants have the potential to greatly alter natural selection on native competitors. Studies investigating altered selection in invaded communities can reveal the potential evolutionary impact of invasive competitors, while deepening our understanding of the more general role of competition in driving plant evolution and permitting species coexistence. © 2015 Botanical Society of America, Inc.

A step-by-step introduction to vegetables at the beginning of complementary feeding. The effects of early and repeated exposure.

PubMed

Hetherington, Marion M; Schwartz, C; Madrelle, J; Croden, F; Nekitsing, C; Vereijken, C M J L; Weenen, H

2015-01-01

Breastfeeding (BF) is associated with willingness to accept vegetables. This may be due to the variety of flavours delivered via breast milk. Some mothers add vegetables to milk during complementary feeding (CF) to enhance acceptance. The present study tested a step-by-step exposure to vegetables in milk then rice during CF, on intake and liking of vegetables. Just before CF, enrolled mothers were randomised to an intervention (IG, n = 18; 6 BF) or control group (CG, n = 18; 6 BF). IG infants received 12 daily exposures to vegetable puree added to milk (days 1-12), then 12 × 2 daily exposures to vegetable puree added to rice at home (days 13-24). Plain milk and rice were given to CG. Then both received 11 daily exposures to vegetable puree. Intake was weighed and liking rated on days 25-26 and 33-35 after the start of CF in the laboratory, supplemented by the same data recorded at home. Vegetables were rotated daily (carrots, green beans, spinach, broccoli). Intake, liking and pace of eating were greater for IG than CG infants. Intake and liking of carrots were greater than green beans. However, at 6m then 18m follow up, vegetable (carrot > green beans) but not group differences were observed. Mothers reported appreciation of the structure and guidance of this systematic approach. Early exposure to vegetables in a step-by-step method could be included in CF guidelines and longer term benefits assessed by extending the exposure period. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Genetic and Environmental Influences on the Growth of Early Reading Skills

ERIC Educational Resources Information Center

Petrill, Stephen A.; Hart, Sara A.; Harlaar, Nicole; Logan, Jessica; Justice, Laura M.; Schatschneider, Christopher; Thompson, Lee; DeThorne, Laura S.; Deater-Deckard, Kirby; Cutting, Laurie

2010-01-01

Background: Studies have suggested genetic and environmental influences on overall level of early reading whereas the larger reading literature has shown environmental influences on the rate of growth of early reading skills. This study is the first to examine the genetic and environmental influences on both initial level of performance and rate…

Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes

USGS Publications Warehouse

Bartlein, P.J.; Edwards, M.E.; Hostetler, Steven W.; Shafer, Sarah; Anderson, P.M.; Brubaker, L. B; Lozhkin, A. V

2015-01-01

Arctic land-cover changes induced by recent global climate change (e.g., expansion of woody vegetation into tundra and effects of permafrost degradation) are expected to generate further feedbacks to the climate system. Past changes can be used to assess our understanding of feedback mechanisms through a combination of process modeling and paleo-observations. The subcontinental region of Beringia (northeastern Siberia, Alaska, and northwestern Canada) was largely ice-free at the peak of deglacial warming and experienced both major vegetation change and loss of permafrost when many arctic regions were still ice covered. The evolution of Beringian climate at this time was largely driven by global features, such as the amplified seasonal cycle of Northern Hemisphere insolation and changes in global ice volume and atmospheric composition, but changes in regional land-surface controls, such as the widespread development of thaw lakes, the replacement of tundra by deciduous forest or woodland, and the flooding of the Bering–Chukchi land bridge, were probably also important. We examined the sensitivity of Beringia's early Holocene climate to these regional-scale controls using a regional climate model (RegCM). Lateral and oceanic boundary conditions were provided by global climate simulations conducted using the GENESIS V2.01 atmospheric general circulation model (AGCM) with a mixed-layer ocean. We carried out two present-day simulations of regional climate – one with modern and one with 11 ka geography – plus another simulation for 6 ka. In addition, we performed five ~ 11 ka climate simulations, each driven by the same global AGCM boundary conditions: (i) 11 ka Control, which represents conditions just prior to the major transitions (exposed land bridge, no thaw lakes or wetlands, widespread tundra vegetation), (ii) sea-level rise, which employed present-day continental outlines, (iii) vegetation change, with deciduous needleleaf and deciduous broadleaf boreal

The role of vegetation in shaping dune morphology

NASA Astrophysics Data System (ADS)

Duran Vinent, O.; Moore, L. J.; Young, D.

2012-12-01

Aeolian dunes naturally emerge under strong winds and sufficient sand supply. They represent the most dynamical feature of the arid and/or coastal landscape and their evolution has the potential to either increase desertification or reduce coastal vulnerability to storms. Although large-scale dune morphology mainly depends on the wind regime and sand availability, vegetation plays an important role in semiarid and/or coastal areas. It is well known that under certain conditions vegetation is able to stabilize dunes, driving a morphological transformation from un-vegetated mobile crescent dunes to static vegetated "parabolic" dunes, de facto paralyzing desertification and initiating land recovery. Furthermore, vegetation is also the primary ingredient in the formation of coastal foredunes, which determine vulnerability to storms, as low dunes are prone to storm-induced erosion and overwash. In both cases, the coupling of biological and geomorphic (physical) processes, in particular vegetation growth and sand transport, governs the evolution of morphology. These processes were implemented in a computational model as part of a previous effort. It was shown that, for a migrating dune, this coupling leads to a negative feedback for dune motion, where an ever denser vegetation implies ever lesser sand transport. The model also predicted the existence of a "mobility index", defined by the vegetation growth rate to sand erosion rate ratio, that fully characterizes the morphological outcome: for indices above a certain threshold biological processes are dominant and dune motion slows after being covered by plants; for lower indices, the physical processes are the dominant ones and the dune remains mobile while vegetation is buried or rooted out. Here, we extend this model to better understand the formation of coastal dunes. We include new physical elements such as the shoreline and water table, as well as different grass species and potential competition among them

A comparative analysis of the diversity of woody vegetation in old-growth and secondary southern Appalachian cove forests

Treesearch

Lyle J. Guyon; Gary L. Rolfe; John M. Edgington; Guillermo A. Mendoza

2003-01-01

Characteristics of woody vegetation were compared across six different southern Appalachian cove forests. Trees greater than 6.35 cm dbh were point sampled and regeneration was tallied on 25 m² subplots at all study sites. Overstory composition and structure differed between secondary and old-growth sites, which were dominated by yellow-poplar and eastern...

Stereophotogrammetry in studies of riparian vegetation dynamics

NASA Astrophysics Data System (ADS)

Hortobagyi, Borbala; Vautier, Franck; Corenblit, Dov; Steiger, Johannes

2014-05-01

Riparian vegetation responds to hydrogeomorphic disturbances and also controls sediment deposition and erosion. Spatio-temporal riparian vegetation dynamics within fluvial corridors have been quantified in many studies using aerial photographs and GIS. However, this approach does not allow the consideration of woody vegetation growth rates (i.e. vertical dimension) which are fundamental when studying feedbacks between the processes of fluvial landform construction and vegetation establishment and succession. We built 3D photogrammetric models of vegetation height based on aerial argentic and digital photographs from sites of the Allier and Garonne Rivers (France). The models were realized at two different spatial scales and with two different methods. The "large" scale corresponds to the reach of the river corridor on the Allier river (photograph taken in 2009) and the "small" scale to river bars of the Allier (photographs taken in 2002, 2009) and Garonne Rivers (photographs taken in 2000, 2002, 2006 and 2010). At the corridor scale, we generated vegetation height models using an automatic procedure. This method is fast but can only be used with digital photographs. At the bar scale, we constructed the models manually using a 3D visualization on the screen. This technique showed good results for digital and also argentic photographs but is very time-consuming. A diachronic study was performed in order to investigate vegetation succession by distinguishing three different classes according to the vegetation height: herbs (<1 m), shrubs (1-4 m) or trees (>4 m). Both methods, i.e. automatic and manual, were employed to study the evolution of the three vegetation classes and the recruitment of new vegetation patches. A comparison was conducted between the vegetation height given by models (automatic and manual) and the vegetation height measured in the field. The manually produced models (small scale) were of a precision of 0.5-1 m, allowing the quantification of woody

Time-lag effects of global vegetation responses to climate change.

PubMed

Wu, Donghai; Zhao, Xiang; Liang, Shunlin; Zhou, Tao; Huang, Kaicheng; Tang, Bijian; Zhao, Wenqian

2015-09-01

Climate conditions significantly affect vegetation growth in terrestrial ecosystems. Due to the spatial heterogeneity of ecosystems, the vegetation responses to climate vary considerably with the diverse spatial patterns and the time-lag effects, which are the most important mechanism of climate-vegetation interactive effects. Extensive studies focused on large-scale vegetation-climate interactions use the simultaneous meteorological and vegetation indicators to develop models; however, the time-lag effects are less considered, which tends to increase uncertainty. In this study, we aim to quantitatively determine the time-lag effects of global vegetation responses to different climatic factors using the GIMMS3g NDVI time series and the CRU temperature, precipitation, and solar radiation datasets. First, this study analyzed the time-lag effects of global vegetation responses to different climatic factors. Then, a multiple linear regression model and partial correlation model were established to statistically analyze the roles of different climatic factors on vegetation responses, from which the primary climate-driving factors for different vegetation types were determined. The results showed that (i) both the time-lag effects of the vegetation responses and the major climate-driving factors that significantly affect vegetation growth varied significantly at the global scale, which was related to the diverse vegetation and climate characteristics; (ii) regarding the time-lag effects, the climatic factors explained 64% variation of the global vegetation growth, which was 11% relatively higher than the model ignoring the time-lag effects; (iii) for the area with a significant change trend (for the period 1982-2008) in the global GIMMS3g NDVI (P < 0.05), the primary driving factor was temperature; and (iv) at the regional scale, the variation in vegetation growth was also related to human activities and natural disturbances. Considering the time-lag effects is quite

Fibroblast growth factor signaling is required for early somatic gonad development in zebrafish.

PubMed

Leerberg, Dena M; Sano, Kaori; Draper, Bruce W

2017-09-01

The vertebrate ovary and testis develop from a sexually indifferent gonad. During early development of the organism, primordial germ cells (the gamete lineage) and somatic gonad cells coalesce and begin to undergo growth and morphogenesis to form this bipotential gonad. Although this aspect of development is requisite for a fertile adult, little is known about the genetic regulation of early gonadogenesis in any vertebrate. Here, we provide evidence that fibroblast growth factor (Fgf) signaling is required for the early growth phase of a vertebrate bipotential gonad. Based on mutational analysis in zebrafish, we show that the Fgf ligand 24 (Fgf24) is required for proliferation, differentiation, and morphogenesis of the early somatic gonad, and as a result, most fgf24 mutants are sterile as adults. Additionally, we describe the ultrastructural elements of the early zebrafish gonad and show that distinct somatic cell populations can be identified soon after the gonad forms. Specifically, we show that fgf24 is expressed in an epithelial population of early somatic gonad cells that surrounds an inner population of mesenchymal somatic gonad cells that are in direct contact with the germ cells, and that fgf24 is required for stratification of the somatic tissue. Furthermore, based on gene expression analysis, we find that differentiation of the inner mesenchymal somatic gonad cells into functional cell types in the larval and early juvenile-stage gonad is dependent on Fgf24 signaling. Finally, we argue that the role of Fgf24 in zebrafish is functionally analogous to the role of tetrapod FGF9 in early gonad development.

Major Contribution of Flowering Time and Vegetative Growth to Plant Production in Common Bean As Deduced from a Comparative Genetic Mapping.

PubMed

González, Ana M; Yuste-Lisbona, Fernando J; Saburido, Soledad; Bretones, Sandra; De Ron, Antonio M; Lozano, Rafael; Santalla, Marta

2016-01-01

Determinacy growth habit and accelerated flowering traits were selected during or after domestication in common bean. Both processes affect several presumed adaptive traits such as the rate of plant production. There is a close association between flowering initiation and vegetative growth; however, interactions among these two crucial developmental processes and their genetic bases remain unexplored. In this study, with the aim to establish the genetic relationships between these complex processes, a multi-environment quantitative trait locus (QTL) mapping approach was performed in two recombinant inbred line populations derived from inter-gene pool crosses between determinate and indeterminate genotypes. Additive and epistatic QTLs were found to regulate flowering time, vegetative growth, and rate of plant production. Moreover, the pleiotropic patterns of the identified QTLs evidenced that regions controlling time to flowering traits, directly or indirectly, are also involved in the regulation of plant production traits. Further QTL analysis highlighted one QTL, on the lower arm of the linkage group Pv01, harboring the Phvul.001G189200 gene, homologous to the Arabidopsis thaliana TERMINAL FLOWER1 ( TFL1 ) gene, which explained up to 32% of phenotypic variation for time to flowering, 66% for vegetative growth, and 19% for rate of plant production. This finding was consistent with previous results, which have also suggested Phvul.001G189200 (PvTFL1y ) as a candidate gene for determinacy locus. The information here reported can also be applied in breeding programs seeking to optimize key agronomic traits, such as time to flowering, plant height and an improved reproductive biomass, pods, and seed size, as well as yield.

Major Contribution of Flowering Time and Vegetative Growth to Plant Production in Common Bean As Deduced from a Comparative Genetic Mapping

PubMed Central

González, Ana M.; Yuste-Lisbona, Fernando J.; Saburido, Soledad; Bretones, Sandra; De Ron, Antonio M.; Lozano, Rafael; Santalla, Marta

2016-01-01

Determinacy growth habit and accelerated flowering traits were selected during or after domestication in common bean. Both processes affect several presumed adaptive traits such as the rate of plant production. There is a close association between flowering initiation and vegetative growth; however, interactions among these two crucial developmental processes and their genetic bases remain unexplored. In this study, with the aim to establish the genetic relationships between these complex processes, a multi-environment quantitative trait locus (QTL) mapping approach was performed in two recombinant inbred line populations derived from inter-gene pool crosses between determinate and indeterminate genotypes. Additive and epistatic QTLs were found to regulate flowering time, vegetative growth, and rate of plant production. Moreover, the pleiotropic patterns of the identified QTLs evidenced that regions controlling time to flowering traits, directly or indirectly, are also involved in the regulation of plant production traits. Further QTL analysis highlighted one QTL, on the lower arm of the linkage group Pv01, harboring the Phvul.001G189200 gene, homologous to the Arabidopsis thaliana TERMINAL FLOWER1 (TFL1) gene, which explained up to 32% of phenotypic variation for time to flowering, 66% for vegetative growth, and 19% for rate of plant production. This finding was consistent with previous results, which have also suggested Phvul.001G189200 (PvTFL1y) as a candidate gene for determinacy locus. The information here reported can also be applied in breeding programs seeking to optimize key agronomic traits, such as time to flowering, plant height and an improved reproductive biomass, pods, and seed size, as well as yield. PMID:28082996

MreB of Streptomyces coelicolor is not essential for vegetative growth but is required for the integrity of aerial hyphae and spores.

PubMed

Mazza, Paola; Noens, Elke E; Schirner, Kathrin; Grantcharova, Nina; Mommaas, A Mieke; Koerten, Henk K; Muth, Günther; Flärdh, Klas; van Wezel, Gilles P; Wohlleben, Wolfgang

2006-05-01

MreB forms a cytoskeleton in many rod-shaped bacteria which is involved in cell shape determination and chromosome segregation. PCR-based and Southern analysis of various actinomycetes, supported by analysis of genome sequences, revealed mreB homologues only in genera that form an aerial mycelium and sporulate. We analysed MreB in one such organism, Streptomyces coelicolor. Ectopic overexpression of mreB impaired growth, and caused swellings and lysis of hyphae. A null mutant with apparently normal vegetative growth was generated. However, aerial hyphae of this mutant were swelling and lysing; spores doubled their volume and lost their characteristic resistance to stress conditions. Loss of cell wall consistency was observed in MreB-depleted spores by transmission electron microscopy. An MreB-EGFP fusion was constructed to localize MreB in the mycelium. No clearly localized signal was seen in vegetative mycelium. However, strong fluorescence was observed at the septa of sporulating aerial hyphae, then as bipolar foci in young spores, and finally in a ring- or shell-like pattern inside the spores. Immunogold electron microscopy using MreB-specific antibodies revealed that MreB is located immediately underneath the internal spore wall. Thus, MreB is not essential for vegetative growth of S. coelicolor, but exerts its function in the formation of environmentally stable spores, and appears to primarily influence the assembly of the spore cell wall.

Changing patterns of Pennsylvanian coal-swamp vegetation and implications of climatic control on coal occurrence

USGS Publications Warehouse

Phillips, T.L.; Peppers, R.A.

1984-01-01

Improved regional and interregional stratigraphic correlations of Pennsylvanian strata permit comparisons of vegetational changes in Euramerican coal swamps. The coal-swamp vegetation is known directly from in situ coal-ball peat deposits from more than 65 coals in the United States and Europe. Interpretations of coal-swamp floras on the basis of coal-ball peat studies are extended to broader regional and stratigraphic patterns by use of coal palynology. Objectives of the quantitative analyses of the vegetation in relation to coal are to determine the botanical constituents at the peat stage and their environmental implications for plant growth and peat accumulation. Morphological and paleoecological analyses provide a basis for deducing freshwater regimes of coal swamps. Changes in composition of Pennsylvanian coal-swamp vegetation are quire similar from one paralic coal region to another and show synchrony that is attributable to climate. Paleobotany and paleogeography of the Euramerican province indicate a moist tropical paleoclimate. Rainfall, runoff and evapotranspiration were the variable climatic controls in the distribution of coal-swamp vegetation, peat accumulation and coal resources. In relative terms of climatic wetness the Pennsylvanian Period is divisible into five intervals, which include two relatively drier intervals that developed during the Lower-Middle and Middle-Upper Pennsylvanian transitions. The climate during Early Pennsylvanian time was moderately wet and the median in moisture availability. Early Middle Pennsylvanian was drier, probably seasonally dry-wet; late Middle Pennsylvanian was the wettest in the Midcontinent; early Late Pennsylvanian was the driest; and late Late Pennsylvanian was probably the wettest in the Dunkard Basin. The five climatic intervals represent a general means of dividing coal resources within each region into groups with similar botanical constituents and environments of peat accumulation. Regional differences in

Effect of Ppd-1 on the expression of flowering-time genes in vegetative and reproductive growth stages of wheat.

PubMed

Kitagawa, Satoshi; Shimada, Sanae; Murai, Koji

2012-01-01

The photoperiod sensitivity gene Ppd-1 influences the timing of flowering in temperate cereals such as wheat and barley. The effect of Ppd-1 on the expression of flowering-time genes was assessed by examining the expression levels of the vernalization genes VRN1 and VRN3/WFT and of two CONSTANS-like genes, WCO1 and TaHd1, during vegetative and reproductive growth stages. Two near-isogenic lines (NILs) were used: the first carried a photoperiod-insensitive allele of Ppd-1 (Ppd-1a-NIL), the other, a photoperiod-sensitive allele (Ppd-1b-NIL). We found that the expression pattern of VRN1 was similar in Ppd-1a-NIL and Ppd-1b-NIL plants, suggesting that VRN1 is not regulated by Ppd-1. Under long day conditions, VRN3/WFT showed similar expression patterns in Ppd-1a-NIL and Ppd-1b-NIL plants. However, expression differed greatly under short day conditions: VRN3/WFT expression was detected in Ppd-1a-NIL plants at the 5-leaf stage when they transited from vegetative to reproductive growth; very low expression was present in Ppd-1b-NIL throughout all growth stages. Thus, the Ppd-1b allele acts to down-regulate VRN3/WFT under short day conditions. WCO1 showed high levels of expression at the vegetative stage, which decreased during the phase transition and reproductive growth stages in both Ppd-1a-NIL and Ppd-1b-NIL plants under short day conditions. By contrast to WCO1, TaHd1 was up-regulated during the reproductive stage. The level of TaHd1 expression was much higher in Ppd-1a-NIL than the Ppd-1b-NIL plants, suggesting that the Ppd-1b allele down-regulates TaHd1 under short day conditions. The present study indicates that down-regulation of VRN3/WFT together with TaHd1 is the cause of late flowering in the Ppd-1b-NIL plants under short day conditions.

Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life.

PubMed

Sant'Ana, Anderson S; Barbosa, Matheus S; Destro, Maria Teresa; Landgraf, Mariza; Franco, Bernadette D G M

2012-06-15

Growth potential (δ) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of δ of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the δ of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7°C) and abuse temperature (15°C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L. monocytogenes was able to grow (δ≥0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L. monocytogenes. The highest δ values were obtained when the RTE vegetables were stored 15°C/6days in collard greens (δ=3.3) and arugula (δ=3.2) (L. monocytogenes) and arugula (δ=4.1) and escarole (δ=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (p<0.05). Counts of lactic acid bacteria were higher in vegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L. monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterizing Seasonal Drought, Water Supply Pattern and Their Impact on Vegetation Growth Using Satellite Soil Moisture Data, GRACE Water Storage and Precipitation Observations

NASA Astrophysics Data System (ADS)

A, G.; Velicogna, I.; Kimball, J. S.; Du, J.; Kim, Y.; Njoku, E. G.; Colliander, A.

2016-12-01

We combine soil moisture (SM) data from AMSR-E, AMSR-2 and SMAP, terrestrial water storage (TWS) changes from GRACE and precipitation measurements from GPCP to delineate and characterize drought and water supply pattern and its impact on vegetation growth. GRACE TWS provides spatially continuous observations of total terrestrial water storage changes and regional drought extent, persistence and severity, while satellite derived soil moisture estimates provide enhanced delineation of plant-available soil moisture. Together these data provide complementary metrics quantifying available plant water supply and have important implications for water resource management. We use these data to investigate the supply changes from different water components in relation to satellite based vegetation productivity metrics from MODIS, before, during and following the major drought events observed in the continental US during the past 13 years. We observe consistent trends and significant correlations between monthly time series of TWS, SM, and vegetation productivity. In Texas and surrounding semi-arid areas, we find that the spatial pattern of the vegetation-moisture relation follows the gradient in mean annual precipitation. In Texas, GRACE TWS and surface SM show strong coupling and similar characteristic time scale in relatively normal years, while during the 2011 onward hydrological drought, GRACE TWS manifests a longer time scale than that of surface SM, implying stronger drought persistence in deeper water storage. In the Missouri watershed, we find a spatially varying vegetation-moisture relationship where in the drier northwestern portion of the basin, the inter-annual variability in summer vegetation productivity is closely associated with changes in carry-on GRACE TWS from spring, whereas in the moist southeastern portion of the basin, summer precipitation is the dominant controlling factor on vegetation growth.

Microbiological community analysis of vermicompost tea and its influence on the growth of vegetables and cereals.

PubMed

Fritz, J I; Franke-Whittle, I H; Haindl, S; Insam, H; Braun, R

2012-07-01

Vermicompost, the digestion product of organic material by earthworms, has been widely reported to have a more positive effect on plant growth and plant health than conventional compost. A study was conducted to investigate the effects of different vermicompost elutriates (aerated compost teas) on soils and plant growth. The teas were analyzed by chemical, microbiological, and molecular methods accompanied by plant growth tests at laboratory and field scale. The number of microorganisms in the teas increased during the extraction process and was affected by substrate addition. The vermicompost tea found to increase plant growth best under laboratory tests was applied to cereals (wheat and barley) and vegetables (Raphanus sativus, Rucola selvatica, and Pisum sativum) in a field study. The results revealed no effects of tea application on plant yield; however, sensoric tests indicated an improvement in crop quality. The soils from laboratory and field studies were investigated to detect possible microbial or chemical changes. The results indicated that minor changes to the soil microbial community occurred following tea application by foliar spray in both the laboratory-scale and field-scale experiments.

Response of Alpine Grassland Vegetation Phenology to Snow Accumulation and Melt in Namco Basin

NASA Astrophysics Data System (ADS)

Chen, S.; Cui, X.; Liang, T.

2018-04-01

Snow/ice accumulation and melt, as a vital part of hydrological processes, is close related with vegetation activities. Taking Namco basin for example, based on multisource remote sensing data and the ground observation data of temperature and precipitation, phenological information was extracted by S-G filtering and dynamic threshold method. Daily snow cover fraction was calculated with daily cloud-free snow cover maps. Evolution characteristics of grassland vegetation greening, growth length and daily snow cover fraction and their relationship were analyzed from 2001 to 2013. The results showed that most of grassland vegetation had advanced greening and prolong growth length trend in Namco basin. There were negative correlations between snow cover fraction and vegetation greening or growth length. The response of vegetation phenology to snow cover fraction is more sensitive than that to temperature in spring. Meanwhile, vegetation growth condition turned worse with advanced greening and prolong growth length. To a certain extent, our research reveals the relationship between grassland vegetation growth cycle and snow in alpine ecosystem. It has provided reference to research the response mechanism of alpine grassland ecosystem to climate changes.

AtTMEM18 plays important roles in pollen tube and vegetative growth in Arabidopsis

PubMed Central

Dou, Xiao‐Ying; Yang, Ke‐Zhen; Ma, Zhao‐Xia; Chen, Li‐Qun; Zhang, Xue‐Qin; Bai, Jin‐Rong

2016-01-01

Abstract In flowering plants, pollen tube growth is essential for delivery of male gametes into the female gametophyte or embryo sac for double fertilization. Although many genes have been identified as being involved in the process, the molecular mechanisms of pollen tube growth remains poorly understood. In this study, we identified that the Arabidopsis Transmembrane Protein 18 (AtTMEM18) gene played important roles in pollen tube growth. The AtTMEM18 shares a high similarity with the Transmembrane 18 proteins (TMEM18s) that are conserved in most eukaryotes and may play important roles in obesity in humans. Mutation in the AtTMEM18 by a Ds insertion caused abnormal callose deposition in the pollen grains and had a significant impact on pollen germination and pollen tube growth. AtTMEM18 is expressed in pollen grains, pollen tubes, root tips and other vegetative tissues. The pollen‐rescued assays showed that the mutation in AtTMEM18 also caused defects in roots, stems, leaves and transmitting tracts. AtTMEM18‐GFP was located around the nuclei. Genetic assays demonstrated that the localization of AtTMEM18 around the nuclei in the generative cells of pollen grains was essential for the male fertility. Furthermore, expression of the rice TMEM18‐homologous protein (OsTMEM18) driven by LAT52 promoter could recover the fertility of the Arabidopsis attmem18 mutant. These results suggested that the TMEM18 is important for plant growth in Arabidopsis. PMID:26699939

Association Between Early Life Growth and Blood Pressure Trajectories in Black South African Children.

PubMed

Kagura, Juliana; Adair, Linda S; Munthali, Richard J; Pettifor, John M; Norris, Shane A

2016-11-01

Early growth is associated with blood pressure measured on one occasion, but whether early life growth patterns are associated with longitudinal blood pressure trajectories is under-researched. Therefore, we sought to examine the association between early growth and blood pressure trajectories from childhood to adulthood. Blood pressure was measured on 7 occasions between ages 5 and 18 years in the Birth to Twenty cohort study, and conditional variables for growth in infancy and mid-childhood were computed from anthropometric measures (n=1937, 52% girls). We used a group-based trajectory modeling approach to identify distinct height-adjusted blood pressure trajectories and then tested their association with growth between birth and mid-childhood adjusting for several covariates. Three trajectory groups were identified for systolic and diastolic blood pressure: lower, middle, and upper in boys and girls, separately. In boys, predictors of the middle or upper systolic blood pressure trajectories versus the lower trajectory were in birth weight (odds ratio 0.75 [95% confidence interval 0.58-0.96] per SD) and relative weight gain in infancy (4.11 [1.25-13.51] per SD). In girls, greater relative weight gain and linear growth in both infancy and mid-childhood were consistently associated with an almost 2-fold higher likelihood of being in the upper versus lower systolic blood pressure trajectory. The associations for the diastolic blood pressure trajectories were inconsistent. These findings emphasize the importance of identifying children at risk of progression to high blood pressure. Accelerated growth in infancy and mid-childhood may be a key target for early life intervention in prevention of elevated blood pressure progression. © 2016 American Heart Association, Inc.

State Indicator Report on Fruits and Vegetables, 2009

ERIC Educational Resources Information Center

Centers for Disease Control and Prevention, 2009

2009-01-01

The "State Indicator Report on Fruits and Vegetables, 2009" provides for the first time information on fruit and vegetable (F&V) consumption and policy and environmental support within each state. Fruits and vegetables, as part of a healthy diet, are important for optimal child growth, weight management, and chronic disease…

Evaporative cooling over the Tibetan Plateau induced by vegetation growth.

PubMed

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

2015-07-28

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.

Evaporative cooling over the Tibetan Plateau induced by vegetation growth

PubMed Central

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

Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

USGS Publications Warehouse

Thullen, J.S.; Sartoris, J.J.; Nelson, S.M.

2002-01-01

The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998–1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia–nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate=9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water.

Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

USGS Publications Warehouse

Thullen, J.S.; Sartoris, J.J.; Walton, W.E.

2002-01-01

The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998-1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia - nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate = 9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water. ?? 2002 Elsevier Science B.V. All rights reserved.

Food, growth and time: Elsie Widdowson's and Robert McCance's research into prenatal and early postnatal growth.

PubMed

Buklijas, Tatjana

2014-09-01

Cambridge scientists Robert McCance and Elsie Widdowson are best known for their work on the British food tables and wartime food rations, but it is their research on prenatal and early postnatal growth that is today seen as a foundation of the fields studying the impact of environment upon prenatal development and, consequently, adult disease. In this essay I situate McCance's and Widdowson's 1940s human and 1950s experimental studies in the context of pre-war concerns with fetal growth and development, especially within biochemistry, physiology and agriculture; and the Second World War and post-war focus on the effects of undernutrition during pregnancy upon the fetus. I relate Widdowson's and McCance's research on the long-term effects of early undernutrition to the concern with recovery from early trauma so pertinent in post-war Europe and with sensitive (critical) periods, a concept of high importance across different fields. Finally I discuss how, following a hiatus in which fetal physiology engaged with different questions and stressed fetal autonomy, interest in the impact of environment upon prenatal growth and development revived towards the end of the twentieth century. The new field of "developmental origins of health and disease", I suggest, has provided a context in which Widdowson's and McCance's work has regained importance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Early Acceleration of Mathematics Students and its Effect on Growth in Self-esteem: A Longitudinal Study

NASA Astrophysics Data System (ADS)

Ma, Xin

2002-11-01

The Longitudinal Study of American Youth (LSAY) database was employed to examine the educational practice of early acceleration of students of mathematics on the development of their self-esteem across the entire secondary grade levels. Students were classified into three different academic categories (gifted, honors, and regular). Results indicated that, in terms of the development of their self-esteem, gifted students benefited from early acceleration, honors students neither benefited nor were harmed by early acceleration, and regular students were harmed by early acceleration. Early acceleration in mathematics promoted significant growth in self-esteem among gifted male students and among gifted, honors, and regular minority students. When students were accelerated, schools showed similar average growth in self-esteem among gifted students and regular students and a large effect of general support for mathematics on the average growth in self-esteem among honors students.

Farming of Vegetables in Space-Limited Environments

NASA Astrophysics Data System (ADS)

He, Jie

2015-10-01

Vegetables that contain most of the essential components of human nutrition are perishable and cannot be stocked. To secure vegetable supply in space limited cities such as Singapore, there are different farming methods to produce vegetables. These include low-cost urban community gardening and innovative rooftop and vertical farms integrated with various technologies such as hydroponics, aquaponics and aeroponics. However, for large-scale vegetable production in space-limited Singapore, we need to develop farming systems that not only increase productivity many-fold per unit of land but also produce all types of vegetable, all year-round for today and the future. This could be resolved through integrated vertical aeroponic farming system. Manipulation of root-zone (RZ) environments such as cooling the RZ, modifying mineral nutrients and introducing elevated RZ CO2 using aeroponics can further boost crop productivity beyond what can be achieved from more efficient use of land area. We could also adopt energy saving light emitting diodes (LEDs) for vertical aeroponic farming system to promote uniform growth and to improve the utilisation of limited space via shortening the growth cycle, thus improving vegetable production in a cost-effective manner.

Investigation of uncertainties of establishment schemes in dynamic global vegetation models

NASA Astrophysics Data System (ADS)

Song, Xiang; Zeng, Xiaodong

2014-01-01

In Dynamic Global Vegetation Models (DGVMs), the establishment of woody vegetation refers to flowering, fertilization, seed production, germination, and the growth of tree seedlings. It determines not only the population densities but also other important ecosystem structural variables. In current DGVMs, establishments of woody plant functional types (PFTs) are assumed to be either the same in the same grid cell, or largely stochastic. We investigated the uncertainties in the competition of establishment among coexisting woody PFTs from three aspects: the dependence of PFT establishments on vegetation states; background establishment; and relative establishment potentials of different PFTs. Sensitivity experiments showed that the dependence of establishment rate on the fractional coverage of a PFT favored the dominant PFT by increasing its share in establishment. While a small background establishment rate had little impact on equilibrium states of the ecosystem, it did change the timescale required for the establishment of alien species in pre-existing forest due to their disadvantage in seed competition during the early stage of invasion. Meanwhile, establishment purely from background (the scheme commonly used in current DGVMs) led to inconsistent behavior in response to the change in PFT specification (e.g., number of PFTs and their specification). Furthermore, the results also indicated that trade-off between individual growth and reproduction/colonization has significant influences on the competition of establishment. Hence, further development of establishment parameterization in DGVMs is essential in reducing the uncertainties in simulations of both ecosystem structures and successions.

Telomere dynamics in wild brown trout: effects of compensatory growth and early growth investment.

PubMed

Näslund, Joacim; Pauliny, Angela; Blomqvist, Donald; Johnsson, Jörgen I

2015-04-01

After a period of food deprivation, animals often respond with a period of faster than normal growth. Such responses have been suggested to result in decreased chromosomal maintenance, which in turn may affect the future fitness of an individual. Here, we present a field experiment in which a food deprivation period of 24 days was enforced on fish from a natural population of juvenile brown trout (Salmo trutta) at the start of the high-growth season in spring. The growth of the food-deprived fish and a non-deprived control group was then monitored in the wild during 1 year. Fin tissue samples were taken at the start of the experiment and 1 year after food deprivation to monitor the telomere dynamics, using reduced telomere length as an indicator of maintenance cost. The food-deprived fish showed partial compensatory growth in both mass and length relative to the control group. However, we found no treatment effects on telomere dynamics, suggesting that growth-compensating brown trout juveniles are able to maintain their telomeres during their second year in the stream. However, body size at the start of the experiment, reflecting growth rate during their first year of life, was negatively correlated with change in telomere length over the following year. This result raises the possibility that rapid growth early in life induces delayed costs in cellular maintenance.

Beyond birth-weight: early growth and adolescent blood pressure in a Peruvian population.

PubMed

Sterling, Robie; Checkley, William; Gilman, Robert H; Cabrera, Lilia; Sterling, Charles R; Bern, Caryn; Miranda, J Jaime

2014-01-01

Background. Longitudinal investigations into the origins of adult essential hypertension have found elevated blood pressure in children to accurately track into adulthood, however the direct causes of essential hypertension in adolescence and adulthood remains unclear. Methods. We revisited 152 Peruvian adolescents from a birth cohort tracked from 0 to 30 months of age, and evaluated growth via monthly anthropometric measurements between 1995 and 1998, and obtained anthropometric and blood pressure measurements 11-14 years later. We used multivariable regression models to study the effects of infantile and childhood growth trends on blood pressure and central obesity in early adolescence. Results. In regression models adjusted for interim changes in weight and height, each 0.1 SD increase in weight for length from 0 to 5 months of age, and 1 SD increase from 6 to 30 months of age, was associated with decreased adolescent systolic blood pressure by 1.3 mm Hg (95% CI -2.4 to -0.1) and 2.5 mm Hg (95% CI -4.9 to 0.0), and decreased waist circumference by 0.6 (95% CI -1.1 to 0.0) and 1.2 cm (95% CI -2.3 to -0.1), respectively. Growth in infancy and early childhood was not significantly associated with adolescent waist-to-hip ratio. Conclusions. Rapid compensatory growth in early life has been posited to increase the risk of long-term cardiovascular morbidities such that nutritional interventions may do more harm than good. However, we found increased weight growth during infancy and early childhood to be associated with decreased systolic blood pressure and central adiposity in adolescence.

Growth curve analyses of the relationship between early maternal age and children's mathematics and reading performance.

PubMed

Torres, D Diego

2015-03-01

Regarding the methods used to examine the early maternal age-child academic outcomes relationship, the extant literature has tended to examine change using statistical analyses that fail to appreciate that individuals vary in their rates of growth. Of the one study I have been able to find that employs a true growth model to estimate this relationship, the authors only controlled for characteristics of the maternal household after family formation; confounding background factors of mothers that might select them into early childbearing, a possible source of bias, were ignored. The authors' findings nonetheless suggested an inverse relationship between early maternal age, i.e., a first birth between the ages of 13 and 17, and Canadian adolescents' mean math performance at age 10. Early maternal age was not related to the linear slope of age. To elucidate whether the early maternal age-child academic outcomes association, treated in a growth context, is consistent with this finding, the present study built on it using US data and explored children's mathematics and reading trajectories from age 5 on. Its unique contribution is that it further explicitly controlled for maternal background factors and employed a three-level growth model with repeated measures of children nested within their mothers. Though the strength of the relationship varied between mean initial academic performance and mean academic growth, results confirmed that early maternal age was negatively related to children's mathematics and reading achievement, net of post-teen first birth child-specific and maternal household factors. Once maternal background factors were included, there was no statistically significant relationship between early maternal age and either children's mean initial mathematics and reading scores or their mean mathematics and reading growth. Copyright © 2014 Elsevier Inc. All rights reserved.

Establishment treatments affect the relationships among nutrition, productivity and competing vegetation of loblolly pine saplings on a Gulf Coastal Plain site

Treesearch

Mary A. Sword; Allan E. Tiarks; James D. Haywood

1998-01-01

After cultural treatments such as site preparation, release, and fertilization, changes in the supply of mineral nutrients relative to each other and shifts in the composition of vegetation may have a delayed effect on the nutrition, carbon partitioning, and growth of forest trees. This study was conducted to evaluate the influence of early management options that...

Predictors of Longitudinal Growth in Inhibitory Control in Early Childhood

PubMed Central

Moilanen, Kristin L.; Shaw, Daniel S.; Dishion, Thomas J.; Gardner, Frances; Wilson, Melvin

2009-01-01

In the current study, we examined latent growth in 731 young children’s inhibitory control from ages 2 to 4, and whether demographic characteristics or parenting behaviors were related to initial levels and growth in inhibitory control. As part of an ongoing longitudinal evaluation of the Family Check-Up (FCU), children’s inhibitory control was assessed yearly at ages 2, 3, and 4. Inhibitory control was initially low and increased linearly to age 4. High levels of harsh parenting and male gender were associated with low initial status in inhibitory control. High levels of supportive parenting were associated with faster growth. Extreme family poverty and African American ethnicity were also associated with slower growth. The results highlight parenting as a target for early interventions in contexts of high socioeconomic risk. PMID:20376201

Optimization of lamp spectrum for vegetable growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prikupets, L.B.; Tikhomirov, A.A.

1994-12-31

Commmercial light sources were evaluated as to the optimum conditions for the production of tomatoes and cucumbers. Data is presented which corresponds to the maximum productivity and optimal spectral ratios. It is suggested that the commercial light sources evaluated were not efficient for the growing of the vegetables.

Late effects of early growth hormone treatment in Down syndrome.

PubMed

Myrelid, Å; Bergman, S; Elfvik Strömberg, M; Jonsson, B; Nyberg, F; Gustafsson, J; Annerén, G

2010-05-01

Down syndrome (DS) is associated with short stature and psychomotor delay. We have previously shown that growth hormone (GH) treatment during infancy and childhood normalizes growth velocity and improves fine motor skill performance in DS. The aim of this study was to investigate late effects of early GH treatment on growth and psychomotor development in the DS subjects from the previous trial. Twelve of 15 adolescents with DS (3 F) from the GH group and 10 of 15 controls (5 F) participated in this follow-up study. Fifteen other subjects with DS (6 F) were included as controls in anthropometric analyses. Cognitive function was assessed with the Leiter International Performance Scale-Revised (Leiter-R) and selected subtests of the Wechsler Intelligence Scale for Children, Third edition (WISC-III). The Bruininks-Oseretsky Test of Motor Proficiency, Second edition (BOT-2), was used to assess general motor ability. Although early GH treatment had no effect on final height, the treated subjects had a greater head circumference standard deviation score (SDS) than the controls (-1.6 SDS vs. -2.2 SDS). The adolescents previously treated with GH had scores above those of the controls in all subtests of Leiter-R and WISC-III, but no difference in Brief IQ-score was seen between the groups. The age-adjusted motor performance of all subjects was below -2 SD, but the GH-treated subjects performed better than the controls in all but one subtest. The combined finding of a greater head circumference SDS and better psychomotor performance indicates that DS subjects may benefit from early GH treatment.

Environmental variability and child growth in Nepal.

PubMed

Shively, Gerald; Sununtnasuk, Celeste; Brown, Molly

2015-09-01

Data from the 2011 Nepal Demographic Health Survey are combined with satellite remotely sensed Normalized Difference Vegetation Index (NDVI) data to evaluate whether interannual variability in weather is associated with child health. For stunting, we focus on children older than 24 months of age. NDVI anomaly averages during cropping months are evaluated during the year before birth, the year of birth, and the second year after birth. For wasting, we assess children under 59 months of age and relate growth to NDVI averages for the current and most recent growing periods. Correlations between short-run indicators of child growth and intensity of green vegetation are generally positive. Regressions that control for a range of child-, mother- and household-specific characteristics produce mixed evidence regarding the role of NDVI anomalies during critical periods in a child's early life and the subsequent probability of stunting and wasting. Overall findings suggest that the relationship between environmental conditions and child growth are heterogeneous across the landscape in Nepal and, in many cases, highly non-linear and sensitive to departures from normality. Copyright © 2015 Elsevier Ltd. All rights reserved.

The importance of nodule CO2 fixation for the efficiency of symbiotic nitrogen fixation in pea at vegetative growth and during pod formation.

PubMed

Fischinger, Stephanie Anastasia; Schulze, Joachim

2010-05-01

Nodule CO2 fixation is of pivotal importance for N2 fixation. The process provides malate for bacteroids and oxaloacetate for nitrogen assimilation. The hypothesis of the present paper was that grain legume nodules would adapt to higher plant N demand and more restricted carbon availability at pod formation through increased nodule CO2 fixation and a more efficient N2 fixation. Growth, N2 fixation, and nodule composition during vegetative growth and at pod formation were studied in pea plants (Pisum sativum L.). In parallel experiments, 15N2 and 13CO2 uptake, as well as nodule hydrogen and CO2 release, was measured. Plants at pod formation showed higher growth rates and N2 fixation per plant when compared with vegetative growth. The specific activity of active nodules was about 25% higher at pod formation. The higher nodule activity was accompanied by higher amino acid concentration in nodules and xylem sap with a higher share of asparagine. Nodule 13CO2 fixation was increased at pod formation, both per plant and per 15N2 fixed unit. However, malate concentration in nodules was only 40% of that during vegetative growth and succinate was no longer detectable. The data indicate that increased N2 fixation at pod formation is connected with strongly increased nodule CO2 fixation. While the sugar concentration in nodules at pod formation was not altered, the concentration of organic acids, namely malate and succinate, was significantly lower. It is concluded that strategies to improve the capability of nodules to fix CO2 and form organic acids might prolong intensive N2 fixation into the later stages of pod formation and pod filling in grain legumes.

Dietary Intake of Protein in Early Childhood Is Associated with Growth Trajectories between 1 and 9 Years of Age.

PubMed

Braun, Kim Ve; Erler, Nicole S; Kiefte-de Jong, Jessica C; Jaddoe, Vincent Wv; van den Hooven, Edith H; Franco, Oscar H; Voortman, Trudy

2016-11-01

High protein intake in infancy might lead to a higher body mass index (BMI) in childhood. However, whether these associations differ between different sources of protein is unclear. We investigated associations between the intake of total protein, protein from different sources, and individual amino acids in early childhood and repeatedly measured height, weight, and BMI up to the age of 9 y. This study was performed in 3564 children participating in the Generation R Study, a population-based prospective cohort study in Rotterdam, Netherlands. Intakes of total protein, animal protein, vegetable protein, and individual amino acids (including methionine, arginine, lysine, threonine, valine, leucine, isoleucine, phenylalanine, tryptophan, histidine, cysteine, tyrosine, alanine, asparagine, glutamine, glycine, proline, and serine) at 1 y were assessed by using a food-frequency questionnaire. Height and weight were measured at the approximate ages of 14, 18, 24, 30, 36, and 45 mo and at 6 and 9 y, and BMI was calculated. After adjustment for confounders, linear mixed models showed that a 10-g higher total protein intake/d at 1 y was significantly associated with a 0.03-SD greater height (95% CI: 0.00, 0.06), a 0.06-SD higher weight (95% CI: 0.03, 0.09), and a 0.05-SD higher BMI (95% CI: 0.03, 0.08) up to the age of 9 y. Associations were stronger for animal than for vegetable protein intake but did not differ between dairy and nondairy animal protein or between specific amino acids. A higher intake of protein, especially animal protein, at 1 y of age was associated with a greater height, weight, and BMI in childhood up to 9 y of age. Future studies should explore the role of growth hormones and investigate whether protein intake in early childhood affects health later in life. © 2016 American Society for Nutrition.

Analysing growth and development of plants jointly using developmental growth stages

PubMed Central

Dambreville, Anaëlle; Lauri, Pierre-Éric; Normand, Frédéric; Guédon, Yann

2015-01-01

Background and Aims Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages. Methods Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages. Key Results Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves. Conclusions Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning. PMID:25452250

Relationships between parenting style, feeding style and feeding practices and fruit and vegetable consumption in early childhood.

PubMed

Blissett, Jackie

2011-12-01

Despite substantial evidence suggesting that a diet high in fruit and vegetables (FV) is associated with reduced risk of cancer, only 21% of children in the UK consume the recommended 5 portions of fruit or vegetables a day. This review examines the role of parenting style, feeding style and feeding practices in FV consumption in early childhood. Whilst inconsistencies in concepts and terminology cloud this literature, overall the evidence suggests that the context of an authoritative parenting and feeding style is associated with better FV consumption in the childhood years. This context is typified by emotional warmth but high expectations for children's dietary adequacy and behaviour, accompanied by specific feeding practices such as modeling consumption of FV, making FV available within the home, covertly restricting unhealthy alternative snack foods, and encouraging children to try FV. Further longitudinal and intervention studies are required to determine the efficacy of modification of parenting style and feeding practice on children's FV intake. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of redistributing windrowed topsoil on growth and development of ponderosa pine plantations

Treesearch

Jianwei Zhang; David H. Young; Kenneth R. Luckow

2015-01-01

Windrowing site preparation often displaces significant amounts of topsoil including nutrients and carbon into the strip-piles. Although short-term growth may increase due to the early control of competing vegetation, this practice can reduce long-term plantation productivity. Here, we report an experiment established in 1989 in a 28-year-old ponderosa pine (

Comparison of Swirl Sign and Black Hole Sign in Predicting Early Hematoma Growth in Patients with Spontaneous Intracerebral Hemorrhage.

PubMed

Xiong, Xin; Li, Qi; Yang, Wen-Song; Wei, Xiao; Hu, Xi; Wang, Xing-Chen; Zhu, Dan; Li, Rui; Cao, Du; Xie, Peng

2018-01-29

BACKGROUND Early hematoma growth is associated with poor outcome in patients with spontaneous intracerebral hemorrhage (ICH). The swirl sign (SS) and the black hole sign (BHS) are imaging markers in ICH patients. The aim of this study was to compare the predictive value of these 2 signs for early hematoma growth. MATERIAL AND METHODS ICH patients were screened for the appearance of the 2 signs within 6 h after onset of symptoms. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 2 signs in predicting early hematoma growth were assessed. The accuracy of the 2 signs in predicting early hematoma growth was analyzed by receiver-operator analysis. RESULTS A total of 200 patients were enrolled in this study. BHS was found in 30 (15%) patients, and SS was found in 70 (35%) patients. Of the 71 patients with early hematoma growth, BHS was found on initial computed tomography scans in 24 (33.8%) and SS in 33 (46.5%). The sensitivity, specificity, PPV, and NPV of BHS for predicting early hematoma growth were 33.8%, 95.3%, 80.0%, and 72.0%, respectively. The sensitivity, specificity, PPV, and NPV of SS were 46.5%, 71.3%, 47.0%, and 71.0%, respectively. The area under the curve was 0.646 for BHS and 0.589 for SS (P=0.08). Multivariate logistic regression showed that presence of BHS is an independent predictor of early hematoma growth. CONCLUSIONS The Black hole sign seems to be good predictor for hematoma growth. The presence of swirl sign on admission CT does not independently predict hematoma growth in patients with ICH.

Germination and early seedling growth of Pinus densata Mast. provenances

Treesearch

Yulan Xu; Nianhui Cai; Bin He; Ruili Zhang; Wei Zhao; Jianfeng Mao; Anan Duan; Yue Li; Keith Woeste

2016-01-01

We studied seed germination and early seedling growth of Pinus densata to explore the range of variability within the species and to inform afforestation practices. Phenotypes were evaluated at a forest tree nursery under conditions that support Pinus yunnanensis, one of the presumed parental species of P. densata...

Status of Vegetation Classification in Redwood Ecosystems

Treesearch

Thomas M. Mahony; John D. Stuart

2007-01-01

Vegetation classifications, based primarily on physiognomic variability and canopy dominants and derived principally from remotely sensed imagery, have been completed for the entire redwood range (Eyre 1980, Fox 1989). However, systematic, quantitative, floristic-based vegetation classifications in old-growth redwood forests have not been completed for large portions...

Snow effects on alpine vegetation in the Qinghai-Tibetan Plateau

USGS Publications Warehouse

Wang, Kun; Zhang, Li; Qiu, Yubao; Ji, Lei; Tian, Feng; Wang, Cuizhen; Wang, Zhiyong

2013-01-01

Understanding the relationships between snow and vegetation is important for interpretation of the responses of alpine ecosystems to climate changes. The Qinghai-Tibetan Plateau is regarded as an ideal area due to its undisturbed features with low population and relatively high snow cover. We used 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) datasets during 2001–2010 to examine the snow–vegetation relationships, specifically, (1) the influence of snow melting date on vegetation green-up date and (2) the effects of snow cover duration on vegetation greenness. The results showed that the alpine vegetation responded strongly to snow phenology (i.e., snow melting date and snow cover duration) over large areas of the Qinghai-Tibetan Plateau. Snow melting date and vegetation green-up date were significantly correlated (p < 0.1) in 39.9% of meadow areas (accounting for 26.2% of vegetated areas) and 36.7% of steppe areas (28.1% of vegetated areas). Vegetation growth was influenced by different seasonal snow cover durations (SCDs) in different regions. Generally, the December–February and March–May SCDs played a significantly role in vegetation growth, both positively and negatively, depending on different water source regions. Snow's positive impact on vegetation was larger than the negative impact.

The MdTFL1 gene of apple (Malus x domestica Borkh.) reduces vegetative growth and generation time.

PubMed

Flachowsky, Henryk; Szankowski, Iris; Waidmann, Sascha; Peil, Andreas; Tränkner, Conny; Hanke, Magda-Viola

2012-10-01

TFL1 is known as a floral repressor in Arabidopsis thaliana (L.) Heynh. In apple there are two TFL1 homologs, MdTFL1-1 and MdTFL1-2. The MdTFL1-1 gene was silenced in transgenic clones expressing a hairpin gene construct of a 323 bp fragment of MdTFL1-1. The hairpin gene construct was transferred to three different apple genotypes. Of 22 transgenic clones, 21 showed a significant reduction in MdTFL1-1 mRNA expression. Precocious flowering was obtained for 20 clones, which flowered already during in vitro cultivation. Nineteen clones could successfully be transferred to the greenhouse where 18 of them flowered within a few weeks followed by the death or at least a strongly inhibited vegetative growth of the plant. Most of the transgenic flowers developed abnormally. Results obtained on greenhouse-grown plants of the transgenic clones and transgenic seedlings clearly demonstrated the major role of MdTFL1 genes in maintaining the vegetative growth as prerequisite for a perennial lifecycle. It was shown that MdTFL1 dsRNAi promotes a life history similar to annual plants. Preliminary results obtained from grafting experiments with non-transgenic scions grafted onto MdTFL1 dsRNAi transgenic rootstocks indicated that the flower-inducing signal obtained after silencing of MdTFL1 genes seems not to be graft-transmissible.

Bioagents and silicon promoting fast early upland rice growth.

PubMed

de Sousa, Thatyane Pereira; de Souza, Alan Carlos Alves; de Filippi, Marta Cristina Corsi; Lanna, Anna Cristina; Cortês, Marcio Vinicius; Pinheiro, Hugo Alves; da Silva, Gisele Barata

2018-02-01

Upland rice can overcome major challenges through the insertion of silicate fertilization and the presence of plant growth-promoting microorganisms (PGPMs) during its cultivation, as these factors promote an increase in vigor and plant disease resistance. Two consecutive experiments were conducted to evaluate the beneficial effects of silicon fertilization combined with the PGPM, Pseudomonas fluorensces, Burkholderia pyrrocinia, and a pool of Trichoderma asperellum, in upland rice seedlings, cultivar BRS Primavera CL: (a) E1, selecting PGPM type and Si doses for rice growth promotion and leaf blast supression, and (b) E2, evaluating physiological characteristics correlated with mechanisms involved in the higher vegetative growth in highlighted treatments from E1. In E1, 2 Si t ha -1 combined with the application of T. asperellum pool or PGPM mixture increased 54% in root dry matter biomass and 35 and 65% in shoot and root lengths, respectively; it also suppressed 99% of rice blast severity. In E2, shoot and root dry matter biomass and length, photosynthetic rate, water use efficiency, total soluble sugar, and chloroplastidic pigments were superior in BRS Primavera CL seedlings treated with 2 Si t ha -1 and T. asperellum pool or PGPM mixture. Higher salicilic and jasmonic acid levels were found in seedlings treated with Si and T. asperellum pool, individually. These physiological characteristics may explain, in part, the higher vigor of upland rice seedlings promoted by the synergistic effect between silicate fertilization and beneficial microorganisms.

Stand Dynamics and Plant Associates of Loblolly Pine Plantations to Midrotation after Early Intensive Vegetation Management-A Southeastern United States Regional Study

Treesearch

James H. Miller; Bruce R. Zutter; Ray A. Newbold; M. Boyd Edwards; Shepard M. Zedaker

2003-01-01

Increasingly, pine plantations worldwide are grown using early control of woodv and/or herbaceous vegetation. Assuredsustainablepractices require long-term data on pine plantation development detailing patterns and processes to understand both crop-competition dynamics and the role of stand participants in providing multiple attributes such as biodiversity conservation...

Modeling the Impact of Forest and Peat Fires on Carbon-Isotopic Compositions of Cretaceous Atmosphere and Vegetation

NASA Astrophysics Data System (ADS)

Finkelstein, D. B.; Pratt, L. M.

2004-12-01

Prevalence of wildfires or peat fires associated with seasonally dry conditions in the Cretaceous is supported by recent studies documenting the widespread presence of pyrolytic polycyclic aromatic hydrocarbons and fusinite. Potential roles of CO2 emissions from fire have been overlooked in many discussions of Cretaceous carbon-isotope excursions (excluding K-P boundary discussions). Enhanced atmospheric CO2 levels could increase fire frequency through elevated lightning activity. When biomass or peat is combusted, emissions of CO2 are more negative than atmospheric CO2. Five reservoirs (atmosphere, vegetation, soil, and shallow and deep oceans), and five fluxes (productivity, respiration, litter fall, atmosphere-ocean exchange, and surface-deep ocean exchange) were modeled as a closed system. The size of the Cretaceous peat reservoir was estimated by compilation of published early Cretaceous coal resources. Initial pCO2 was assumed to be 2x pre-industrial atmospheric levels (P.A.L.). Critical variables in the model are burning efficiency and post-fire growth rates. Assuming 1% of standing terrestrial biomass is consumed by wildfires each year for ten years (without combustion of peat), an increase of atmospheric CO2 (from 2.0 to 2.2x P.A.L.) and a negative carbon isotope excursion (-1.2 ‰ ) are recorded by both atmosphere and new growth. Net primary productivity linked to the residence time of the vegetation and soil reservoirs results in a negative isotope shift followed by a broad positive isotope excursion. Decreasing the rate of re-growth dampens this trailing positive shift and increases the duration of the excursion. Post-fire pCO2 and new growth returned to initial values after 72 years. Both negative and positive isotope excursions are recorded in the model in surface ocean waters. Exchange of CO2 with the surface- and deep-ocean dampens the isotopic shift of the atmosphere. Excursions are first recorded in the atmosphere (and new growth), followed by

Root-zone temperature and water availability affect early root growth of planted longleaf pine

Treesearch

M.A. Sword

1995-01-01

Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...

Nitrogen Use Efficiency of Coffee at the Vegetative Stage as Influenced by Fertilizer Application Method

PubMed Central

Salamanca-Jimenez, Alveiro; Doane, Timothy A.; Horwath, William R.

2017-01-01

Nitrogen (N) is the most limiting nutrient for coffee production in Colombia. An adequate supply is especially important during the vegetative period of growth, since any deficiency during this short period is known to have lasting effects on subsequent coffee bean production. Urea fertilizer is commonly applied on the soil surface since steep slopes hamper incorporation into soil, a practice which increases the risk of N volatilization. Little information is available on N recovery during early growth stages under different fertilizer application practices. The aim of this study was therefore to provide a comparison of 15N uptake during the early vegetative growth stage under surface-applied and incorporation practices at two contrasting locations. The highest proportion of plant N derived from fertilizer (Ndff) occurred 60 days following application at the site with greater precipitation and soil organic matter, where surface application also increased the Ndff in roots and stems after 120 days. Although fertilizer N supplied approximately 20–29% of total plant N after 4 months, this fertilizer-derived N corresponded on average to only 5% of the total application, indicating that very little fertilizer (relative to how much is applied) reaches plants during this time. Apart from the difference in Ndff observed at the wetter site, there was no effect of application method on dry weight and macronutrient content in different plant components, root to shoot ratio, and leaf 13C content. However, site effects were registered for most of these measurements, with the exception of total nutrient uptake. Similarly to Ndff trends, lower root/shoot ratio and higher concentrations of N, K, and Mg in aboveground biomass were found in the site with higher rainfall and soil organic matter, likely resulting from higher soil water and N availability. These findings provide new information useful as a direction for further research looking toward increasing NUE during the

Monitoring and Characterizing Seasonal Drought, Water Supply Pattern and Their Impact on Vegetation Growth Using Satellite Soil Moisture Data, GRACE Water Storage and In-situ Observations.

NASA Astrophysics Data System (ADS)

A, G.; Velicogna, I.; Kimball, J. S.; Kim, Y.; Colliander, A.; Njoku, E. G.

2015-12-01

We combine soil moisture (SM) data from AMSR-E, AMSR-2 and SMAP, terrestrial water storage (TWS) changes from GRACE, in-situ groundwater measurements and atmospheric moisture data to delineate and characterize the evolution of drought and its impact on vegetation growth. GRACE TWS provides spatially continuous observations of total terrestrial water storage changes and regional drought extent, persistence and severity, while satellite derived soil moisture estimates provide enhanced delineation of plant-available soil moisture. Together these data provide complementary metrics quantifying available plant water supply. We use these data to investigate the supply changes from water components at different depth in relation to satellite based vegetation metrics, including vegetation greenness (NDVI) measures from MODIS and related higher order productivity (GPP) before, during and following the major drought events observed in the continental US for the past 14 years. We observe consistent trends and significant correlations between monthly time series of TWS, SM, NDVI and GPP. We study how changes in atmosphere moisture stress and coupling of water storage components at different depth impact on the spatial and temporal correlation between TWS, SM and vegetation metrics. In Texas, we find that surface SM and GRACE TWS agree with each other in general, and both capture the underlying water supply constraints to vegetation growth. Triggered by a transit increase in precipitation following the 2011 hydrological drought, vegetation productivity in Texas shows more sensitivity to surface SM than TWS. In the Great Plains, the correspondence between TWS and vegetation productivity is modulated by temperature-induced atmosphere moisture stress and by the coupling between surface soil moisture and groundwater through irrigation.

The Growth of Early Galaxies and Reionization of Hydrogen

NASA Astrophysics Data System (ADS)

Chary, Ranga Ram

2012-07-01

The reionization of the intergalactic medium about a billion years after the Big Bang was an important event which occurred due to the release of ionizing photons from the growth of stellar mass and black holes in the early Universe. By leveraging the benefits of field galaxy surveys, I will present some recent breakthroughs in our understanding of how the earliest galaxies in the Universe evolved. I will present evidence that unlike in the local Universe where galaxy growth occurs through intermittent cannibalism, star-formation in the distant Universe is a more continuous if violent process with an overabundance of massive stars. Implications for the reionization history of the Universe will also be discussed.

STATISTICAL GROWTH MODELING OF LONGITUDINAL DT-MRI FOR REGIONAL CHARACTERIZATION OF EARLY BRAIN DEVELOPMENT.

PubMed

Sadeghi, Neda; Prastawa, Marcel; Fletcher, P Thomas; Gilmore, John H; Lin, Weili; Gerig, Guido

2012-01-01

A population growth model that represents the growth trajectories of individual subjects is critical to study and understand neurodevelopment. This paper presents a framework for jointly estimating and modeling individual and population growth trajectories, and determining significant regional differences in growth pattern characteristics applied to longitudinal neuroimaging data. We use non-linear mixed effect modeling where temporal change is modeled by the Gompertz function. The Gompertz function uses intuitive parameters related to delay, rate of change, and expected asymptotic value; all descriptive measures which can answer clinical questions related to growth. Our proposed framework combines nonlinear modeling of individual trajectories, population analysis, and testing for regional differences. We apply this framework to the study of early maturation in white matter regions as measured with diffusion tensor imaging (DTI). Regional differences between anatomical regions of interest that are known to mature differently are analyzed and quantified. Experiments with image data from a large ongoing clinical study show that our framework provides descriptive, quantitative information on growth trajectories that can be directly interpreted by clinicians. To our knowledge, this is the first longitudinal analysis of growth functions to explain the trajectory of early brain maturation as it is represented in DTI.

Vegetation response to early holocene warming as an analog for current and future changes: Special section

USGS Publications Warehouse

Cole, K.L.

2010-01-01

Temperatures in southwestern North America are projected to increase 3.5-4 ??C over the next 60-90 years. This will precipitate ecological shifts as the ranges of species change in response to new climates. During this shift, rapid-colonizing species should increase, whereas slow-colonizing species will at first decrease, but eventually become reestablished in their new range. This successional process has been estimated to require from 100 to over 300 years in small areas, under a stable climate, with a nearby seed source. How much longer will it require on a continental scale, under a changing climate, without a nearby seed source? I considered this question through an examination of the response of fossil plant assemblages from the Grand Canyon, Arizona, to the most recent rapid warming of similar magnitude that occurred at the start of the Holocene, 11,700 years ago. At that time, temperatures in southwestern North America increased about 4 ??C over less than a century. Grand Canyon plant species responded at different rates to this warming climate. Early-successional species rapidly increased, whereas late-successional species decreased. This shift persisted throughout the next 2700 years. I found two earlier, less-extreme species shifts following rapid warming events around 14,700 and 16,800 years ago. Late-successional species predominated only after 4000 years or more of relatively stable temperature. These results suggest the potential magnitude, duration, and nature of future ecological changes and have implications for conservation plans, especially those incorporating equilibrium assumptions or reconstituting past conditions. When these concepts are extended to include the most rapid early-successional colonizers, they imply that the recent increases in invasive exotics may be only the most noticeable part of a new resurgence of early-successional vegetation. Additionally, my results challenge the reliability of models of future vegetation and carbon

High-latitude tree growth and satellite vegetation indices: Correlations and trends in Russia and Canada (1982-2008)

NASA Astrophysics Data System (ADS)

Berner, Logan T.; Beck, Pieter S. A.; Bunn, Andrew G.; Lloyd, Andrea H.; Goetz, Scott J.

2011-03-01

Vegetation in northern high latitudes affects regional and global climate through energy partitioning and carbon storage. Spaceborne observations of vegetation, largely based on the normalized difference vegetation index (NDVI), suggest decreased productivity during recent decades in many regions of the Eurasian and North American boreal forests. To improve interpretation of NDVI trends over forest regions, we examined the relationship between NDVI from the advanced very high resolution radiometers and tree ring width measurements, a proxy of tree productivity. We collected tree core samples from spruce, pine, and larch at 22 sites in northeast Russia and northwest Canada. Annual growth rings were measured and used to generate site-level ring width index (RWI) chronologies. Correlation analysis was used to assess the association between RWI and summer NDVI from 1982 to 2008, while linear regression was used to examine trends in both measurements. The correlation between NDVI and RWI was highly variable across sites, though consistently positive (r = 0.43, SD = 0.19, n = 27). We observed significant temporal autocorrelation in both NDVI and RWI measurements at sites with evergreen conifers (spruce and pine), though weak autocorrelation at sites with deciduous conifers (larch). No sites exhibited a positive trend in both NDVI and RWI, although five sites showed negative trends in both measurements. While there are technological and physiological limitations to this approach, these findings demonstrate a positive association between NDVI and tree ring measurements, as well as the importance of considering lagged effects when modeling vegetation productivity using satellite data.

Putative floral brood-site mimicry, loss of autonomous selfing, and reduced vegetative growth are significantly correlated with increased diversification in Asarum (Aristolochiaceae).

PubMed

Sinn, Brandon T; Kelly, Lawrence M; Freudenstein, John V

2015-08-01

The drivers of angiosperm diversity have long been sought and the flower-arthropod association has often been invoked as the most powerful driver of the angiosperm radiation. We now know that features that influence arthropod interactions cannot only affect the diversification of lineages, but also expedite or constrain their rate of extinction, which can equally influence the observed asymmetric richness of extant angiosperm lineages. The genus Asarum (Aristolochiaceae; ∼100 species) is widely distributed in north temperate forests, with substantial vegetative and floral divergence between its three major clades, Euasarum, Geotaenium, and Heterotropa. We used Binary-State Speciation and Extinction Model (BiSSE) Net Diversification tests of character state distributions on a Maximum Likelihood phylogram and a Coalescent Bayesian species tree, inferred from seven chloroplast markers and nuclear rDNA, to test for signal of asymmetric diversification, character state transition, and extinction rates of floral and vegetative characters. We found that reduction in vegetative growth, loss of autonomous self-pollination, and the presence of putative fungal-mimicking floral structures are significantly correlated with increased diversification in Asarum. No significant difference in model likelihood was identified between symmetric and asymmetric rates of character state transitions or extinction. We conclude that the flowers of the Heterotropa clade may have converged on some aspects of basidiomycete sporocarp morphology and that brood-site mimicry, coupled with a reduction in vegetative growth and the loss of autonomous self-pollination, may have driven diversification within Asarum. Copyright © 2015 Elsevier Inc. All rights reserved.

Cutting Diameter Influences Early Survival and Growth of Several Populus Clones

Treesearch

Donald Dickmann; Howard Phipps; Daniel Netzer

1980-01-01

The effects of cutting diameter on early survival and growth of several Populus clones were studied in field tests in Wisconsin and Michigan. Generally, large diameter cuttings survived and grew better than small diameter cuttings. Response differences among clones were evident.

LANDFIRE 2015 Remap – Utilization of Remotely Sensed Data to Classify Existing Vegetation Type and Structure to Support Strategic Planning and Tactical Response

USGS Publications Warehouse

Picotte, Joshua J.; Long, Jordan; Peterson, Birgit; Nelson, Kurtis

2017-01-01

The LANDFIRE Program produces national scale vegetation, fuels, fire regimes, and landscape disturbance data for the entire U.S. These data products have been used to model the potential impacts of fire on the landscape [1], the wildfire risks associated with land and resource management [2, 3], and those near population centers and accompanying Wildland Urban Interface zones [4], as well as many other applications. The initial LANDFIRE National Existing Vegetation Type (EVT) and vegetation structure layers, including vegetation percent cover and height, were mapped circa 2001 and released in 2009 [5]. Each EVT is representative of the dominant plant community within a given area. The EVT layer has since been updated by identifying areas of landscape change and modifying the vegetation types utilizing a series of rules that consider the disturbance type, severity of disturbance, and time since disturbance [6, 7]. Non-disturbed areas were adjusted for vegetation growth and succession. LANDFIRE vegetation structure layers also have been updated by using data modeling techniques [see 6 for a full description]. The subsequent updated versions of LANDFIRE include LANDFIRE 2008, 2010, 2012, and LANDFIRE 2014 is being incrementally released, with all data being released in early 2017. Additionally, a comprehensive remap of the baseline data, LANDFIRE 2015 Remap, is being prototyped, and production is tentatively planned to begin in early 2017 to provide a more current baseline for future updates.

Exploring the control of land-atmospheric oscillations over terrestrial vegetation productivity

NASA Astrophysics Data System (ADS)

Depoorter, Mathieu; Green, Julia; Gentine, Pierre; Liu, Yi; van Eck, Christel; Regnier, Pierre; Dorigo, Wouter; Verhoest, Niko; Miralles, Diego

2015-04-01

Vegetation dynamics play an important role in the climate system due to their control on the carbon, energy and water cycles. The spatiotemporal variability of vegetation is regulated by internal climate variability as well as natural and anthropogenic forcing mechanisms, including fires, land use, volcano eruptions or greenhouse gas emissions. Ocean-atmospheric oscillations, affect the fluxes of heat and water over continents, leading to anomalies in radiation, precipitation or temperature at widely separated locations (i.e. teleconnections); an effect of ocean-atmospheric oscillations on terrestrial primary productivity can therefore be expected. While different studies have shown the general importance of internal climate variability for global vegetation dynamics, the control by particular teleconnections over the regional growth and decay of vegetation is still poorly understood. At continental to global scales, satellite remote sensing offers a feasible approach to enhance our understanding of the main drivers of vegetation variability. Traditional studies of the multi-decadal variability of global vegetation have been usually based on the normalized difference vegetation index (NDVI) derived from the Advanced Very High Resolution Radiometer (AVHRR), which extends back to the early '80s. There are, however, some limitations to NDVI observations; arguably the most important of these limitations is that from the plant physiology perspective the index does not have a well-defined meaning, appearing poorly correlated to vegetation productivity. On the other hand, recently developed records from other remotely-sensed properties of vegetation, like fluorescence or microwave vegetation optical depth, have proven a significantly better correspondence to above-ground biomass. To enhance our understanding of the controls of ocean-atmosphere oscillations over vegetation, we propose to explore the link between climate oscillation extremes and net primary productivity

Examination of the semi-automatic calculation technique of vegetation cover rate by digital camera images.

NASA Astrophysics Data System (ADS)

Takemine, S.; Rikimaru, A.; Takahashi, K.

The rice is one of the staple foods in the world High quality rice production requires periodically collecting rice growth data to control the growth of rice The height of plant the number of stem the color of leaf is well known parameters to indicate rice growth Rice growth diagnosis method based on these parameters is used operationally in Japan although collecting these parameters by field survey needs a lot of labor and time Recently a laborsaving method for rice growth diagnosis is proposed which is based on vegetation cover rate of rice Vegetation cover rate of rice is calculated based on discriminating rice plant areas in a digital camera image which is photographed in nadir direction Discrimination of rice plant areas in the image was done by the automatic binarization processing However in the case of vegetation cover rate calculation method depending on the automatic binarization process there is a possibility to decrease vegetation cover rate against growth of rice In this paper a calculation method of vegetation cover rate was proposed which based on the automatic binarization process and referred to the growth hysteresis information For several images obtained by field survey during rice growing season vegetation cover rate was calculated by the conventional automatic binarization processing and the proposed method respectively And vegetation cover rate of both methods was compared with reference value obtained by visual interpretation As a result of comparison the accuracy of discriminating rice plant areas was increased by the proposed

Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A.

USGS Publications Warehouse

De Steven, Diane; Faulkner, Stephen; Keeland, Bobby D.; Baldwin, Michael; McCoy, John W.; Hughes, Steven C.

2015-01-01

In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespreadconversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs haveattempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (afforestation)and local hydrologic enhancement on reclaimed croplands. Early assessments identified factors that influenced whetherplanting plus tree colonization could establish an overstory community similar to natural bottomland forests. The extentto which afforested sites develop typical understory vegetation has not been evaluated, yet understory composition may beindicative of restored site conditions. As part of a broad study quantifying the ecosystem services gained from restorationefforts, understory vegetation was compared between 37 afforested sites and 26 mature forest sites. Differences in vegetationattributes for species growth forms, wetland indicator classes, and native status were tested with univariate analyses;floristic composition data were analyzed by multivariate techniques. Understory vegetation of restoration sites was generallyhydrophytic, but species composition differed from that of mature bottomland forest because of young successional age anddiffering responses of plant growth forms. Attribute and floristic variation among restoration sites was related to variationin canopy development and local wetness conditions, which in turn reflected both intrinsic site features and outcomes ofrestoration practices. Thus, understory vegetation is a useful indicator of functional progress in floodplain forest restoration.

Germination and Early Growth of Brassica juncea in Copper Mine Tailings Amended with Technosol and Compost

PubMed Central

González, Luís

2014-01-01

Mine tailings represent a serious threat to the environment and human health; thus their restoration has become a major concern. In this study, the interactions between Brassica juncea and different mine soil treatments were evaluated in order to understand their effect on germination and early growth. Three soil treatments containing 25% and 50% of technosol and 30% of compost were prepared. Germination and early growth were assessed in soil and pore water extracts from the treatments. Unlike the untreated mine soil, the three treatments allowed germination and growth, achieving levels comparable to those of seedlings from the same species developed in normal conditions. The seedlings grown in 50% of technosol and 30% of compost exhibited greater germination percentages, higher growth, and more efficient mechanisms against oxidative stress, ascribed to the organic matter and nutrients content of these treatments. Considering the unequivocal ability of B. juncea for phytoremediation, the results suggest that technosol and compost may be an auspicious solution to allow the germination and early growth of this species in mine tailings. PMID:25386602

The Relationship between Early Growth and Survival of Hatchling Saltwater Crocodiles (Crocodylus porosus) in Captivity

PubMed Central

Brien, Matthew L.; Webb, Grahame J.; McGuinness, Keith; Christian, Keith A.

2014-01-01

Hatchling fitness in crocodilians is affected by “runtism” or failure to thrive syndrome (FTT) in captivity. In this study, 300 hatchling C. porosus, artificially incubated at 32°C for most of their embryonic development, were raised in semi-controlled conditions, with growth criteria derived for the early detection of FTT (within 24 days). Body mass, four days after hatching (BM4d), was correlated with egg size and was highly clutch specific, while snout-vent length (SVL4d) was much more variable within and between clutches. For the majority of hatchlings growth trajectories within the first 24 days continued to 90 days and could be used to predict FTT affliction up to 300 days, highlighting the importance of early growth. Growth and survival of hatchling C. porosus in captivity was not influenced by initial size (BM4d), with a slight tendency for smaller hatchlings to grow faster in the immediate post-hatching period. Strong clutch effects (12 clutches) on affliction with FTT were apparent, but could not be explained by measured clutch variables or other factors. Among individuals not afflicted by FTT (N = 245), mean growth was highly clutch specific, and the variation could be explained by an interaction between clutch and season. FTT affliction was 2.5 times higher among clutches (N = 7) that hatched later in the year when mean minimum air temperatures were lower, compared with those clutches (N = 5) that hatched early in the year. The results of this study highlight the importance of early growth in hatchling C. porosus, which has implications for the captive management of this species. PMID:24960026

Global Enhanced Vegetation Index

NASA Technical Reports Server (NTRS)

2002-01-01

By carefully measuring the wavelengths and intensity of visible and near-infrared light reflected by the land surface back up into space, the Moderate-resolution Imaging Spectroradiometer (MODIS) Team can quantify the concentrations of green leaf vegetation around the world. The above MODIS Enhanced Vegetation Index (EVI) map shows the density of plant growth over the entire globe. Very low values of EVI (white and brown areas) correspond to barren areas of rock, sand, or snow. Moderate values (light greens) represent shrub and grassland, while high values indicate temperate and tropical rainforests (dark greens). The MODIS EVI gives scientists a new tool for monitoring major fluctuations in vegetation and understanding how they affect, and are affected by, regional climate trends. For more information, read NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Land Group/Vegetation Indices, Alfredo Huete, Principal Investigator, and Kamel Didan, University of Arizona

Early Literacy Individual Growth and Development Indicators (EL-IGDIs): Growth Trajectories Using a Large, Internet-Based Sample

ERIC Educational Resources Information Center

Roseth, Cary J.; Missall, Kristen N.; McConnell, Scott R.

2012-01-01

Early literacy individual growth and development indicators (EL-IGDIs) assess preschoolers' expressive vocabulary development and phonological awareness. This study investigated longitudinal change in EL-IGDIs using a large (N=7355), internet-based sample of 36- to 60-month-old United States preschoolers without identified risks for later…

Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

PubMed Central

Qi, Xiaoli; Wu, Wei; Shah, Farooq; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Liu, Hongyan; Nie, Lixiao

2012-01-01

Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding. PMID:22454611

Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.

PubMed

Wang, Zhiwei; Wang, Qian; Wu, Xiaodong; Zhao, Lin; Yue, Guangyang; Nan, Zhuotong; Wang, Puchang; Yi, Shuhua; Zou, Defu; Qin, Yu; Wu, Tonghua; Shi, Jianzong

2017-01-01

The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) product based on turning points (TPs), which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI) and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost regions than the

Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas

PubMed Central

Wu, Xiaodong; Zhao, Lin; Yue, Guangyang; Nan, Zhuotong; Wang, Puchang; Yi, Shuhua; Zou, Defu; Qin, Yu; Wu, Tonghua; Shi, Jianzong

2017-01-01

The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) product based on turning points (TPs), which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI) and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost regions than the

Elongator promotes germination and early post-germination growth.

PubMed

Woloszynska, Magdalena; Gagliardi, Olimpia; Vandenbussche, Filip; Van Lijsebettens, Mieke

2018-01-02

The Elongator complex interacts with RNA polymerase II and via histone acetylation and DNA demethylation facilitates epigenetically the transcription of genes involved in diverse processes in plants, including growth, development, and immune response. Recently, we have shown that the Elongator complex promotes hypocotyl elongation and photomorphogenesis in Arabidopsis thaliana by regulating the photomorphogenesis and growth-related gene network that converges on genes implicated in cell wall biogenesis and hormone signaling. Here, we report that germination in the elo mutant was delayed by 6 h in the dark when compared to the wild type in a time lapse and germination assay. A number of germination-correlated genes were down-regulated in the elo transcriptome, suggesting a transcriptional regulation by Elongator. We also show that the hypocotyl elongation defect observed in the elo mutants in darkness originates very early in the post-germination development and is independent from the germination delay.

Vegetation Health and Productivity Indicators for Sustained National Climate Assessments

NASA Astrophysics Data System (ADS)

Jones, M. O.; Running, S. W.

2014-12-01

The National Climate Assessment process is developing a system of physical, ecological, and societal indicators that communicate key aspects of the physical climate, climate impacts, vulnerabilities, and preparedness for the purpose of informing both decision makers and the public. Implementing a 14 year record of Gross and Net Primary Productivity (GPP/NPP) derived from the NASA EOS MODIS satellite sensor we demonstrate how these products can serve as Ecosystem Productivity and Vegetation Health National Climate Indicators for implementation in sustained National Climate Assessments. The NPP product combines MODIS vegetation data with daily global meteorology to calculate annual growth of all plant material at 1 sq. km resolution. NPP anomalies identify regions with above or below average plant growth that may result from climate fluctuations and can inform carbon source/sink dynamics, agricultural and forestry yield measures, and response to wildfire or drought conditions. The GPP product provides a high temporal resolution (8-day) metric of vegetation growth which can be used to monitor short-term vegetation response to extreme events and implemented to derive vegetation phenology metrics; growing season start, end, and length, which can elucidate land cover and regionally specific vegetation responses to a changing climate. The high spatial resolution GPP and NPP indicators can also inform and clarify responses seen from other proposed Pilot Indicators such as forest growth/productivity, land cover, crop production, and phenology. The GPP and NPP data are in continuous production and will be sustained into the future with the next generation satellite missions. The long-term Ecosystem Productivity and Vegetation Health Indicators are ideal for use in sustained National Climate Assessments, providing regionally specific responses to a changing climate and complete coverage at the national scale.

Analysing growth and development of plants jointly using developmental growth stages.

PubMed

Dambreville, Anaëlle; Lauri, Pierre-Éric; Normand, Frédéric; Guédon, Yann

2015-01-01

Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages. Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages. Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves. Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Developmental plasticity of growth and digestive efficiency in dependence of early-life food availability

PubMed Central

Kotrschal, Alexander; Szidat, Sönke; Taborsky, Barbara

2014-01-01

Nutrition is a potent mediator of developmental plasticity. If food is scarce, developing organisms may invest into growth to outgrow size-dependent mortality (short-term benefit) and/or into an efficient digestion system (long-term benefit). We investigated this potential trade-off, by determining the influence of food availability on juvenile body and organ growth, and on adult digestive efficiency in the cichlid fish Simochromis pleurospilus. We reared two groups of fish at constant high or low food rations, and we switched four other groups between these two rations at an early and late juvenile period. We measured juvenile growth and organ sizes at different developmental stages and determined adult digestive efficiency. Fish kept at constant, high rations grew considerably faster than low-food fish. Nevertheless, S. pleurospilus partly buffered the negative effects of low food availability by developing heavier digestive organs, and they were therefore more efficient in digesting their food as adults. Results of fish exposed to a ration switch during either the early or late juvenile period suggest (i) that the ability to show compensatory growth after early exposure to low food availability persists during the juvenile period, (ii) that digestive efficiency is influenced by varying juvenile food availability during the late juvenile phase and (iii) that the efficiency of the adult digestive system is correlated with the growth rate during a narrow time window of juvenile period. PMID:25866430

Perturbations in growth trajectory due to early diet affect age-related deterioration in performance.

PubMed

Lee, Who-Seung; Monaghan, Pat; Metcalfe, Neil B

2016-04-01

Fluctuations in early developmental conditions can cause changes in growth trajectories that subsequently affect the adult phenotype. Here, we investigated whether compensatory growth has long-term consequences for patterns of senescence.Using three-spined sticklebacks ( Gasterosteus aculeatus ), we show that a brief period of dietary manipulation in early life affected skeletal growth rate not only during the manipulation itself, but also during a subsequent compensatory phase when fish caught up in size with controls.However, this growth acceleration influenced swimming endurance and its decline over the course of the breeding season, with a faster decline in fish that had undergone faster growth compensation.Similarly, accelerated growth led to a more pronounced reduction in the breeding period (as indicated by the duration of sexual ornamentation) over the following two breeding seasons, suggesting faster reproductive senescence. Parallel experiments showed a heightened effect of accelerated growth on these age-related declines in performance if the fish were under greater time stress to complete their compensation prior to the breeding season.Compensatory growth led to a reduction in median life span of 12% compared to steadily growing controls. While life span was independent of the eventual adult size attained, it was negatively correlated with the age-related decline in swimming endurance and sexual ornamentation.These results, complementary to those found when growth trajectories were altered by temperature rather than dietary manipulations, show that the costs of accelerated growth can last well beyond the time over which growth rates differ and are affected by the time available until an approaching life-history event such as reproduction.

Earlier vegetation green-up has reduced spring dust storms

PubMed Central

Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

2014-01-01

The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p < 0.01) between green-up date and dust storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = −0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world. PMID:25343265

Earlier vegetation green-up has reduced spring dust storms.

PubMed

Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

2014-10-24

The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p < 0.01) between green-up date and dust storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world.

Alternative Student Growth Measures for Teacher Evaluation: Implementation Experiences of Early-Adopting Districts. REL 2015-093

ERIC Educational Resources Information Center

McCullough, Moira; English, Brittany; Angus, Megan Hague; Gill, Brian

2015-01-01

Alternative student growth measures for teacher evaluation: Implementation experiences of early-adopting districts: State requirements to include student achievement growth in teacher evaluations are prompting the development of alternative ways to measure growth in grades and subjects not covered by state assessments. These alternative growth…

Stimulation of methane oxidation potential and effects on vegetation growth by bottom ash addition in a landfill final evapotranspiration cover.

PubMed

Kim, Gil Won; Ho, Adrian; Kim, Pil Joo; Kim, Sang Yoon

2016-09-01

The landfilling of municipal solid waste is a significant source of atmospheric methane (CH4), contributing up to 20% of total anthropogenic CH4 emissions. The evapotranspiration (ET) cover system, an alternative final cover system in waste landfills, has been considered to be a promising way to mitigate CH4 emissions, as well as to prevent water infiltration using vegetation on landfill cover soils. In our previous studies, bottom ash from coal-fired power plants was selected among several industrial residues (blast furnace slag, bottom ash, construction waste, steel manufacture slag, stone powder sludge, and waste gypsum) as the best additive for ET cover systems, with the highest mechanical performance achieved for a 35% (wtwt(-1)) bottom ash content in soil. In this study, to evaluate the field applicability of bottom ash mixed soil as ET cover, four sets of lysimeters (height 1.2m×width 2m×length 6m) were constructed in 2007, and four different treatments were installed: (i) soil+bottom ash (35% wtwt(-1)) (SB); (ii) soil+compost (2% wtwt(-1), approximately corresponding to 40Mgha(-1) in arable field scale) (SC); (iii) soil+bottom ash+compost (SBC); and (iv) soil only as the control (S). The effects of bottom ash mixing in ET cover soil on CH4 oxidation potential and vegetation growth were evaluated in a pilot ET cover system in the 5th year after installation by pilot experiments using the treatments. Our results showed that soil properties were significantly improved by bottom ash mixing, resulting in higher plant growth. Bottom ash addition significantly increased the CH4 oxidation potential of the ET cover soil, mainly due to improved organic matter and available copper concentration, enhancing methanotrophic abundances in soil amended with bottom ash. Conclusively, bottom ash could be a good alternative as a soil additive in the ET cover system to improve vegetation growth and mitigate CH4 emission impact in the waste landfill system. Copyright © 2016

Replacement of dietary fish oil with vegetable oils improves the growth and flesh quality of large yellow croaker ( Larmichthys crocea)

NASA Astrophysics Data System (ADS)

Duan, Qingyuan; Mai, Kangsen; Shentu, Jikang; Ai, Qinghui; Zhong, Huiying; Jiang, Yujian; Zhang, Lu; Zhang, Chunxiao; Guo, Sitong

2014-06-01

We investigated the effect of the replacement of dietary fish oil with vegetable oils on the growth and flesh quality of large yellow croaker ( Larmichthys crocea). The basal diet (FO) was formulated to contain 66.5% fish meal and 6.4% menhaden fish oil; whereas the other 3 experimental diets were formulated by replacing the fish oil with 50% soybean oil (SO50), 100% soybean oil (SO100) and 100% palm oil (PO100), respectively. The 4 diets were randomly assigned to 4 floating sea cages (3.0 m × 3.0 m × 3.0 m), and each was stocked with 250 fish individuals with an initial average weight of 245.29 g ± 7.45 g. The fish were fed to apparent satiation twice a day at 5:00 and 17:00, respectively, for 12 weeks. Experimental analysis showed that the specific growth rate of fish fed SO50 or PO100 were significantly higher than that of fish fed FO or SO100 ( P<0.05), and crude lipid contents of ventral muscle and viscera were significantly lower in fish fed FO than in those fed the other 3 diets ( P<0.05). No significant differences in condition factor, viscerosomatic index, hepatosomatic index, gutted yield and colorimetric values of fish among the dietary treatments were observed ( P>0.05). Compared to FO diet, SO50, SO100 and PO100 diets led to substantial decreases in the liquid loss and water loss from fresh fillets (1 d, 4°C) ( P<0.05). Similarly, thiobarbituric acid reactive substance (TBARS) values of fillets under different storage conditions (1 d, 4°C; 7 d, 4°C; 4 weeks, -20°C; 8 weeks, -20°C) decreased significantly after partial or complete replacement of fish oil with vegetable oils. These findings indicated that the growth performance and selected flesh quality properties (liquid holding capacity and TBARS value) of large yellow croaker were substantially improved by replacing dietary fish oil with vegetable oils.

Physical growth and cognitive skills in early-life: evidence from a nationally representative US birth cohort.

PubMed

Murasko, Jason E

2013-11-01

This paper establishes associations between length/height and cognitive skills in infancy, toddlerhood, and school-entry. The data come from the Early Childhood Longitudinal Study--Birth Cohort (ECLS-B), a representative longitudinal sample of US children born in 2001. A positive association between length/height and cognition is found as early as 9 months and continues through school-entry. These associations are robust to controls for birthweight and economic status. Early growth is also shown to be a stronger predictor of reading and math skills in kindergarten than attained height. Girls exhibit stronger evidence of this latter result than boys. These findings have implications for the interpretation of early life as a critical period for the growth-cognition relationship. Copyright © 2012 Elsevier Ltd. All rights reserved.

Estimates of Tropical C4 and C3 Savannah Vegetation Changes during the Holocene from Paleodata and Model Simulations

NASA Astrophysics Data System (ADS)

Khon, V. C.; Wang, Y.; Krebs-Kanzow, U.; Schneider, R. R.; Schneider, B.

2013-12-01

The Savannah vegetation in Southern tropical Africa, which is characterized by co-dominance of grassland and woodland savannah, has a vast importance for global primary production. The mechanisms controlling tree-grass coexistence and the relative roles of environmental factors that determine the tree-grass proportion are not fully understood. The purpose of our study is to estimate the relative contributions of changes in climate and atmospheric CO2 to the evolution of the C3/C4 vegetation balance in the past. We use the BIOME4 vegetation model to estimate the sensitivity of the relative abundance of C4 vegetation to changes in temperature, precipitation and atmospheric CO2. The BIOME4 model is forced by temperature and precipitation anomalies from simulations of the Holocene period with the Kiel Climate Model (KCM). Precipitation reconstructed from dD of leaf wax material obtained from a marine sediment core demonstrates a tendency towards drier conditions over the Zambezi catchment area during the early Holocene. This agrees well with results of the KCM simulations forced by changes in orbital parameters. The simulations of BIOME4 forced by reduced rainfall in combination with the lower level of atmospheric CO2 (without temperature change) show an enhancement of the C4 vegetation abundance. However, the estimates of reconstructed C4/C3 vegetation ratio for the Zambezi basin retrieved from d13C of sedimentary leaf wax do not indicate a substantial trend over the last 10 000 years. We find that the growth of the C4 vegetation ratio could have been significantly attenuated by the (simulated) temperature decrease, especially during the growing season. The latter is caused by a decline in local summer insolation together with the effect of negative radiative forcing due to lower concentrations of greenhouse gases during the early Holocene.

[Effects of different fertilization modes on vegetable growth, fertilizer nitrogen utilization, and nitrogen loss from vegetable field].

PubMed

Huang, Dong-feng; Wang, Guo; Li, Wei-hua; Qiu, Xiao-xuan

2009-03-01

A field experiment with Chinese cabbage, water spinach, and three-colored amaranth cropped three times in one year was conducted to study the effects of seven fertilization modes, i.e., none fertilization, basal application of chemical fertilizers, 1/2 basal application and 1/2 top-dressing of chemical fertilizers, basal application of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and dicyandiamide, 1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure, and basal application of organic manure, on the plant height, yield, nitrogen accumulation, and fertilizer nitrogen utilization of the vegetables, and the loss of NO3- -N and NH4+ -N from vegetable field under natural rainfall condition. The results showed that comparing with none fertilization, the fertilization modes '1/2 basal application and 1/2 top-dressing of chemical fertilizers and organic manure' and 'basal application of chemical fertilizers and dicyandiamide' improved the agronomic properties of test vegetables, increased their yields by 103%-219% and 93%-226%, and nitrogen accumulation by 153% -216% and 231%-320%, respectively, and enhanced fertilizer nitrogen utilization rate. They also decreased the surface runoff loss of NO3- -N and NH4+ -N by 48.1% and 46.5%, respectively, compared with the mode 'basal application of chemical fertilizers', and hence, reduced the risk of agricultural non-point pollution. Therefore, these two fertilization modes could be popularized in vegetable production.

Promotion of human early embryonic development and blastocyst outgrowth in vitro using autocrine/paracrine growth factors.

PubMed

Kawamura, Kazuhiro; Chen, Yuan; Shu, Yimin; Cheng, Yuan; Qiao, Jie; Behr, Barry; Pera, Renee A Reijo; Hsueh, Aaron J W

2012-01-01

Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, key polypeptide ligands known to be important for early embryonic development in animal models were tested for their ability to improve human early embryo development and blastocyst outgrowth in vitro. We confirmed the expression of key ligand/receptor pairs in cleavage embryos derived from discarded human tri-pronuclear zygotes and in human endometrium. Combined treatment with key embryonic growth factors (brain-derived neurotrophic factor, colony-stimulating factor, epidermal growth factor, granulocyte macrophage colony-stimulating factor, insulin-like growth factor-1, glial cell-line derived neurotrophic factor, and artemin) in serum-free media promoted >2.5-fold the development of tri-pronuclear zygotes to blastocysts. For normally fertilized embryos, day 3 surplus embryos cultured individually with the key growth factors showed >3-fold increases in the development of 6-8 cell stage embryos to blastocysts and >7-fold increase in the proportion of high quality blastocysts based on Gardner's criteria. Growth factor treatment also led to a 2-fold promotion of blastocyst outgrowth in vitro when day 7 surplus hatching blastocysts were used. When failed-to-be-fertilized oocytes were used to perform somatic cell nuclear transfer (SCNT) using fibroblasts as donor karyoplasts, inclusion of growth factors increased the progression of reconstructed SCNT embryos to >4-cell stage embryos. Growth factor supplementation of serum-free cultures could promote optimal early embryonic development and implantation in IVF-ET and SCNT procedures. This approach is valuable for infertility

Gα proteins Gvm2 and Gvm3 regulate vegetative growth, asexual development, and pathogenicityon apple in Valsa mali.

PubMed

Song, Na; Dai, Qingqing; Zhu, Baitao; Wu, Yuxing; Xu, Ming; Voegele, Ralf Thomas; Gao, Xiaoning; Kang, Zhensheng; Huang, Lili

2017-01-01

In fungi, heterotrimeric guanine-nucleotide binding proteins (G-proteins) are key elements of signal transduction pathways, which control growth, asexual and sexual development, as well as virulence. In this study, we have identified two genes encoding heterotrimeric G protein alpha subunits, named Gvm2 and Gvm3, from Valsa mali, the causal agent of apple Valsa canker. Characterization of Gvm2 and Gvm3 mutants indicates that Gvm3 may be a crucial regulator of vegetative growth. Deletion of the corresponding gene results in a 20% reduction in growth rate. Besides, Gvm2 and Gvm3 seem to be involved in asexual reproduction, and mutants are hypersensitive to oxidative and cell membrane stresses. Interestingly, both G protein alpha subunits were most probably involved in V. mali virulence. In infection assays using Malus domestica cv. 'Fuji' leaves and twigs, the size of lesions caused by deletion mutants △Gvm2, or △Gvm3 are significantly reduced. Furthermore, many genes encoding hydrolytic enzymes-important virulence factors in V. mali-are expressed at a lower level in these deletion mutants. Our results suggest that Gvm2 and Gvm3 play an important role in virulence probably by regulation of expression of cell wall degrading enzymes. △Gvm2, and △Gvm3 mutants were further analyzed with respect to their impact on the transcript levels of genes in the cAMP/PKA pathway. The expression of the genes encoding adenylate cyclase VmAC, protein kinase A (PKA) regulatory subunit VmPKR, and PKA catalytic subunit VmPKA1 are down-regulated in both mutants. Further analyses indicated that intracellular cAMP level and PKA activity are down-regulated in the △Gvm3 mutant, but are basically unchanged in the △Gvm2 mutant. Overall, our findings indicate that both Gvm2 and Gvm3 play diverse roles in the modulation of vegetative growth, asexual development, and virulence in V. mali.

Complications of growth-sparing surgery in early onset scoliosis.

PubMed

Akbarnia, Behrooz A; Emans, John B

2010-12-01

Review of available literature, authors' opinion. To describe complications associated with growth-sparing surgical treatment of early onset scoliosis (EOS). EOS has many potential etiologies and is often associated with thoracic insufficiency syndrome. The growth of the spine, thorax, and lungs are interrelated, and severe EOS typically involves disturbance of the normal development of all 3. Severe EOS may be treated during growth with surgical techniques, intended to preserve growth while controlling deformity, the most common of which are spinal "growing rods" (GR) or "vertical expandable prosthetic titanium rib" (VEPTR). Although presently popular, there is minimal long-term data on the outcome of growth-sparing surgical techniques on EOS. Review. Potential adverse outcomes of GR or VEPTR treatment of EOS include failure to prevent progressive deformity or thoracic insufficiency syndrome, an unacceptably short or stiff spine or deformed thorax, increased family burden of care, and potentially negative psychological consequences from repeated surgical interventions. Neither technique reliably controls all deformity over the entirety of growth period. Infections are common to both GR and VEPTR. Rod breakage and spontaneous premature spinal fusion beneath rods are troublesome complications in GR, whereas drift of rib attachments and chest wall scarring are anticipated complications in VEPTR treatment. Indications for GR and VEPTR overlap, but thoracogenic scoliosis and severe upper thoracic kyphosis are best treated by VEPTR and GR, respectively. Surgeons planning treatment of EOS should anticipate the many complications common to growth-sparing surgery, share their knowledge with families, and use complications as one factor in the complex decision as to when and whether to initiate the repetitive surgeries associated with GR or VEPTR in the treatment of severe EOS.

Autophagy contributes to regulation of nuclear dynamics during vegetative growth and hyphal fusion in Fusarium oxysporum.

PubMed

Corral-Ramos, Cristina; Roca, M Gabriela; Di Pietro, Antonio; Roncero, M Isabel G; Ruiz-Roldán, Carmen

2015-01-01

In the fungal pathogen Fusarium oxysporum, vegetative hyphal fusion triggers nuclear mitotic division in the invading hypha followed by migration of a nucleus into the receptor hypha and degradation of the resident nucleus. Here we examined the role of autophagy in fusion-induced nuclear degradation. A search of the F. oxysporum genome database for autophagy pathway components identified putative orthologs of 16 core autophagy-related (ATG) genes in yeast, including the ubiquitin-like protein Atg8, which is required for the formation of autophagosomal membranes. F. oxysporum Foatg8Δ mutants were generated in a strain harboring H1-cherry fluorescent protein (ChFP)-labeled nuclei to facilitate analysis of nuclear dynamics. The Foatg8Δ mutants did not show MDC-positive staining in contrast to the wild type and the FoATG8-complemented (cFoATG8) strain, suggesting that FoAtg8 is required for autophagy in F. oxysporum. The Foatg8Δ strains displayed reduced rates of hyphal growth, conidiation, and fusion, and were significantly attenuated in virulence on tomato plants and in the nonvertebrate animal host Galleria mellonella. In contrast to wild-type hyphae, which are almost exclusively composed of uninucleated hyphal compartments, the hyphae of the Foatg8Δ mutants contained a significant fraction of hyphal compartments with 2 or more nuclei. The increase in the number of nuclei per hyphal compartment was particularly evident after hyphal fusion events. Time-lapse microscopy analyses revealed abnormal mitotic patterns during vegetative growth in the Foatg8Δ mutants. Our results suggest that autophagy mediates nuclear degradation after hyphal fusion and has a general function in the control of nuclear distribution in F. oxysporum.

Autophagy contributes to regulation of nuclear dynamics during vegetative growth and hyphal fusion in Fusarium oxysporum

PubMed Central

Corral-Ramos, Cristina; Roca, M Gabriela; Di Pietro, Antonio; Roncero, M Isabel G; Ruiz-Roldán, Carmen

2015-01-01

In the fungal pathogen Fusarium oxysporum, vegetative hyphal fusion triggers nuclear mitotic division in the invading hypha followed by migration of a nucleus into the receptor hypha and degradation of the resident nucleus. Here we examined the role of autophagy in fusion-induced nuclear degradation. A search of the F. oxysporum genome database for autophagy pathway components identified putative orthologs of 16 core autophagy-related (ATG) genes in yeast, including the ubiquitin-like protein Atg8, which is required for the formation of autophagosomal membranes. F. oxysporum Foatg8Δ mutants were generated in a strain harboring H1-cherry fluorescent protein (ChFP)-labeled nuclei to facilitate analysis of nuclear dynamics. The Foatg8Δ mutants did not show MDC-positive staining in contrast to the wild type and the FoATG8-complemented (cFoATG8) strain, suggesting that FoAtg8 is required for autophagy in F. oxysporum. The Foatg8Δ strains displayed reduced rates of hyphal growth, conidiation, and fusion, and were significantly attenuated in virulence on tomato plants and in the nonvertebrate animal host Galleria mellonella. In contrast to wild-type hyphae, which are almost exclusively composed of uninucleated hyphal compartments, the hyphae of the Foatg8Δ mutants contained a significant fraction of hyphal compartments with 2 or more nuclei. The increase in the number of nuclei per hyphal compartment was particularly evident after hyphal fusion events. Time-lapse microscopy analyses revealed abnormal mitotic patterns during vegetative growth in the Foatg8Δ mutants. Our results suggest that autophagy mediates nuclear degradation after hyphal fusion and has a general function in the control of nuclear distribution in F. oxysporum. PMID:25560310

Early Childhood Memory and Attention as Predictors of Academic Growth Trajectories

ERIC Educational Resources Information Center

Stipek, Deborah; Valentino, Rachel A.

2015-01-01

Longitudinal data from the children of the National Longitudinal Survey of Youth (NLSY) were used to assess how well measures of short-term and working memory and attention in early childhood predicted longitudinal growth trajectories in mathematics and reading comprehension. Analyses also examined whether changes in memory and attention were more…

Vegetation role in controlling the ecoenvironmental conditions for sustainable urban environments: a comparison of Beijing and Islamabad

NASA Astrophysics Data System (ADS)

Naeem, Shahid; Cao, Chunxiang; Waqar, Mirza Muhammad; Wei, Chen; Acharya, Bipin Kumar

2018-01-01

The rapid increase in urbanization due to population growth leads to the degradation of vegetation in major cities. This study investigated the spatial patterns of the ecoenvironmental conditions of inhabitants of two distinct Asian capital cities, Beijing of China and Islamabad of Pakistan, by utilizing Earth observation data products. The significance of urban vegetation for the cooling effect was studied in local climate zones, i.e., urban, suburban, and rural areas within 1-km2 quantiles. Landsat-8 (OLI) and Gaofen-1 satellite imagery were used to assess vegetation cover and land surface temperature, while population datasets were used to evaluate environmental impact. Comparatively, a higher cooling effect of vegetation presence was observed in rural and suburban zones of Beijing as compared to Islamabad, while the urban zone of Islamabad was found comparatively cooler than Beijing's urban zone. The urban thermal field variance index calculated from satellite imagery was ranked into the ecological evaluation index. The worst ecoenvironmental conditions were found in urban zones of both cities where the fraction of vegetation is very low. Meanwhile, this condition is more serious in Beijing, as more than 90% of the total population is living under the worst ecoenvironment conditions, while only 7% of the population is enjoying comfortable conditions. Ecoenvironmental conditions of Islamabad are comparatively better than Beijing where ˜61% of the total population live under the worst ecoenvironmental conditions, and ˜24% are living under good conditions. Thus, Islamabad at this early growth stage can learn from Beijing's ecoenvironmental conditions to improve the quality of living by controlling the associated factors in the future.

Early growth and chronic disease: a public health overview.

PubMed

Law, Catherine

2005-07-01

Infant and childhood growth result from and reflect a range of influences in pre- and postnatal life. These include nutrition, burden of infection and the psycho-social environment. Nutrition in young children is dependent on individual level factors such as fetal experience, infant feeding and weaning practices, and on societal factors such as education of women and economic conditions. The relationship of early postnatal growth to adult disease may be indicative or causal, and may reveal both biological and sociological processes. Although non-insulin-dependent diabetes mellitus (NIDDM) and obesity are risk factors for ischaemic heart disease, the relationships of these three conditions to infant growth differ. Poor infant growth has been associated with higher levels of NIDDM and ischaemic heart disease, but lower levels of adult obesity. Most research has been of populations living in developed countries at different stages of nutritional transition. However, differences in context are not simply limited to the stage of the nutritional transition. They also need to consider the nature of that transition and its social correlates, which may result in the clustering of aetiological influences such as increased body mass and poverty. The size of effect of the relationship of infant growth to adult disease is important not only to determine its relative aetiological importance but also for its potential for public health policy. Such policy also needs to consider the relationships of infant growth to a range of outcomes, both health and human capital, which are not the subject of this workshop.

Early Life Growth Predictors of Childhood Adiposity Trajectories and Future Risk for Obesity: Birth to Twenty Cohort.

PubMed

Munthali, Richard J; Kagura, Juliana; Lombard, Zané; Norris, Shane A

2017-10-01

There is growing evidence of variations in adiposity trajectories among individuals, but the influence of early life growth patterns on these trajectories is underresearched in low- and middle-income countries. Therefore, our aim was to examine the association between early life conditional weight gain and childhood adiposity trajectories. We previously identified distinct adiposity trajectories (four for girls and three for boys) in black South African children (boys = 877; girls = 947). The association between the trajectories and early life growth patterns, and future obesity risk was assessed by multivariate linear and multinomial logistic and logistic regressions. Conditional weight gain independent of height was computed for infancy (0-2 years) and early childhood (2-4 years). Conditional weight gain before 5 years of age was significantly associated with early onset of obesity or overweight (excess weight) BMI trajectories in both boys and girls. In girls, greater conditional weight gain in infancy was associated with increased relative risk of being in the early-onset obese to morbid obese trajectory, with relative risk ratios of 2.03 (95% confidence interval: 1.17-3.52) compared to belonging to a BMI trajectory in the normal range. Boys and girls in the early-onset obesity or overweight BMI trajectories were more likely to be overweight or obese in early adulthood. Excessive weight gain in infancy and early childhood, independent of linear growth, predicts childhood and adolescent BMI trajectories toward obesity. These results underscore the importance of early life factors in the development of obesity and other NCDs in later life.

Vegetation shifts observed in arctic tundra 17 years after fire

USGS Publications Warehouse

Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine Janet; Shaver, Gaius

2012-01-01

With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensing imagery and ground observations of the burn scar and an adjacent control site. Early-season remotely sensed imagery from the burn scar exhibits a low vegetation index compared with the control site, whereas the late-season signal is slightly higher. The range and maximum vegetation index are greater in the burn scar, although the mean annual values do not differ among the sites. Ground observations revealed a greater abundance of moss in the unburned site, which may account for the high early growing season normalized difference vegetation index (NDVI) anomaly relative to the burn. The abundance of graminoid species and an absence of Betula nana in the post-fire tundra sites may also be responsible for the spectral differences observed in the remotely sensed imagery. The partial replacement of tundra by graminoid-dominated ecosystems has been predicted by the ALFRESCO model of disturbance, climate and vegetation succession.

Effects of drought stress on growth, solute accumulation and membrane stability of leafy vegetable, huckleberry (Solanum scabrum Mill.).

PubMed

Assaha, Dekoum Vincent Marius; Liu, Liyun; Ueda, Akihiro; Nagaoka, Toshinori; Saneoka, Hirofumi

2016-01-01

The present study sought to investigate the factors implicated in growth impairment of huckleberry (a leafy vegetable) under water stress conditions. To achieve this, seedlings of plant were subjected to control, mild stress and severe stress conditions for 30 days. Plant growth, plant water relation, gas exchange, oxidative stress damage, electrolyte leakage rate, mineral content and osmolyte accumulation were measured. Water deficit markedly decreased leaf, stem and root growth. Leaf photosynthetic rate was tremendously reduced by decrease in stomatal conductance under stress conditions. Malondialdehyde (MDA) content markedly increased under mild (82%) and severe (131%) stress conditions, while electrolyte leakage rate (ELR) increased by 59% under mild stress and 3-fold under severe stress. Mineral content in leafwas high in stressed plants, while proline content markedly increased under mild stress (12-fold) and severe stress (15-fold), with corresponding decrease in osmotic potential at full turgor and an increase in osmotic adjustment. These results suggest that maintenance of high mineral content and osmotic adjustment constitute important adaptations in huckleberry under water deficit conditions and that growth depression under drought stress would be mainly caused by increased electrolyte leakage resulting from membrane damage induced by oxidative stress.

Effects of climate change on forest vegetation [Chapter 6

Treesearch

Patrick N. Behrens; Robert E. Keane; David L. Peterson; Joanne J. Ho

2018-01-01

Projected rapid changes in climate will affect vegetation assemblages in the Intermountain Adaptation Partnership (IAP) region directly and indirectly. Direct effects include altered vegetation growth, mortality, and regeneration, and indirect effects include changes in disturbance regimes (Chapter 8) and interactions with altered ecosystem processes (e.g., hydrology,...

[Estimation model for daily transpiration of greenhouse muskmelon in its vegetative growth period].

PubMed

Zhang, Da-Long; Li, Jian-Ming; Wu, Pu-Te; Li, Wei-Li; Zhao, Zhi-Hua; Xu, Fei; Li, Jun

2013-07-01

For developing an estimation method of muskmelon transpiration in greenhouse, an estimation model for the daily transpiration of greenhouse muskmelon in its vegetative growth period was established, based on the greenhouse environmental parameters, muskmelon growth and development parameters, and soil moisture parameters. According to the specific environment in greenhouse, the item of aerodynamics in Penman-Monteith equation was modified, and the greenhouse environmental sub-model suitable for calculating the reference crop evapotranspiration in greenhouse was deduced. The crop factor sub-model was established with the leaf area index as independent variable, and the form of the model was linear function. The soil moisture sub-model was established with the soil relative effective moisture content as independent variable, and the form of the model was logarithmic function. With interval sowing, the model parameters were estimated and analyzed, according to the measurement data of different sowing dates in a year. The prediction accuracy of the model for sufficient irrigation and water-saving irrigation was verified, according to measurement data when the relative soil moisture content was 80%, 70%, and 60%, and the mean relative error was 11.5%, 16.2% , and 16.9% respectively. The model was a beneficial exploration for the application of Penman-Monteith equation under greenhouse environment and water-saving irrigation, having good application foreground and popularization value.

Phenology Shifts at Start vs. End of Growing Season in Temperate Vegetation Over the Northern Hemisphere for the Period 1982-2008

NASA Technical Reports Server (NTRS)

Jeong, Su-Jong; Ho, Chang-Hoi; Gim, Hyeon-Ju; Brown, Molley E.

2011-01-01

Changes in vegetative growing seasons are dominant indicators of the dynamic response of ecosystems to climate change. Therefore, knowledge of growing seasons over the past decades is essential to predict ecosystem changes. In this study, the long-term changes in the growing seasons of temperate vegetation over the Northern Hemisphere were examined by analyzing satellite-measured normalized difference vegetation index and reanalysis temperature during 1982 2008. Results showed that the length of the growing season (LOS) increased over the analysis period; however, the role of changes at the start of the growing season (SOS) and at the end of the growing season (EOS) differed depending on the time period. On a hemispheric scale, SOS advanced by 5.2 days in the early period (1982-1999) but advanced by only 0.2 days in the later period (2000-2008). EOS was delayed by 4.3 days in the early period, and it was further delayed by another 2.3 days in the later period. The difference between SOS and EOS in the later period was due to less warming during the preseason (January-April) before SOS compared with the magnitude of warming in the preseason (June September) before EOS. At a regional scale, delayed EOS in later periods was shown. In North America, EOS was delayed by 8.1 days in the early period and delayed by another 1.3 days in the later period. In Europe, the delayed EOS by 8.2 days was more significant than the advanced SOS by 3.2 days in the later period. However, in East Asia, the overall increase in LOS during the early period was weakened in the later period. Admitting regional heterogeneity, changes in hemispheric features suggest that the longer-lasting vegetation growth in recent decades can be attributed to extended leaf senescence in autumn rather than earlier spring leaf-out. Keywords: climate change, growing season, NDVI (normalized difference vegetation index), Northern Hemisphere, phenology,

Early childhood neurodevelopment after intrauterine growth restriction: a systematic review.

PubMed

Levine, Terri A; Grunau, Ruth E; McAuliffe, Fionnuala M; Pinnamaneni, RagaMallika; Foran, Adrienne; Alderdice, Fiona A

2015-01-01

Children who experienced intrauterine growth restriction (IUGR) may be at increased risk for adverse developmental outcomes in early childhood. The objective of this study was to carry out a systematic review of neurodevelopmental outcomes from 6 months to 3 years after IUGR. PubMed, Embase, PsycINFO, Maternity and Infant Care, and CINAHL databases were searched by using the search terms intrauterine, fetal, growth restriction, child development, neurodevelopment, early childhood, cognitive, motor, speech, language. Studies were eligible for inclusion if participants met specified criteria for growth restriction, follow-up was conducted within 6 months to 3 years, methods were adequately described, non-IUGR comparison groups were included, and full English text of the article was available. A specifically designed data extraction form was used. The methodological quality of included studies was assessed using well-documented quality-appraisal guidelines. Of 731 studies reviewed, 16 were included. Poorer neurodevelopmental outcomes after IUGR were described in 11. Ten found motor, 8 cognitive, and 7 language delays. Other delays included social development, attention, and adaptive behavior. Only 8 included abnormal Doppler parameters in their definitions of IUGR. Evidence suggests that children are at risk for poorer neurodevelopmental outcomes following IUGR from 6 months to 3 years of age. The heterogeneity of primary outcomes, assessment measures, adjustment for confounding variables, and definitions of IUGR limits synthesis and interpretation. Sample sizes in most studies were small, and some examined preterm IUGR children without including term IUGR or AGA comparison groups, limiting the value of extant studies. Copyright © 2015 by the American Academy of Pediatrics.

Large scale pre-rain vegetation green up across Africa.

PubMed

Adole, Tracy; Dash, Jadunandan; Atkinson, Peter M

2018-05-16

Information on the response of vegetation to different environmental drivers, including rainfall, forms a critical input to ecosystem models. Currently, such models are run based on parameters that, in some cases, are either assumed or lack supporting evidence (e.g., that vegetation growth across Africa is rainfall-driven). A limited number of studies have reported that the onset of rain across Africa does not fully explain the onset of vegetation growth, for example, drawing on the observation of pre-rain flush effects in some parts of Africa. The spatial extent of this pre-rain green-up effect, however, remains unknown, leaving a large gap in our understanding that may bias ecosystem modelling. This paper provides the most comprehensive spatial assessment to-date of the magnitude and frequency of the different patterns of phenology response to rainfall across Africa, and for different vegetation types. To define the relations between phenology and rainfall, we investigated the spatial variation in the difference, in number of days, between the start of rainy season (SRS) and start of vegetation growing season (SOS); and between the end of rainy season (ERS) and end of vegetation growing season (EOS). We reveal a much more extensive spread of pre-rain green-up over Africa than previously reported, with pre-rain green-up being the norm rather than the exception. We also show the relative sparsity of post-rain green-up, confined largely to the Sudano-Sahel region. While the pre-rain green-up phenomenon is well documented, its large spatial extent was not anticipated. Our results, thus, contrast with the widely held view that rainfall drives the onset and end of the vegetation growing season across Africa. Our findings point to a much more nuanced role of rainfall in Africa's vegetation growth cycle than previously thought, specifically as one of a set of several drivers, with important implications for ecosystem modelling. This article is protected by copyright. All

Laser light and magnetic field stimulation effect on biochemical, enzymes activities and chlorophyll contents in soybean seeds and seedlings during early growth stages.

PubMed

Asghar, Tehseen; Jamil, Yasir; Iqbal, Munawar; Zia-Ul-Haq; Abbas, Mazhar

2016-12-01

Laser and magnetic field bio-stimulation attracted the keen interest of scientific community in view of their potential to enhance seed germination, seedling growth, physiological, biochemical and yield attributes of plants, cereal crops and vegetables. Present study was conducted to appraise the laser and magnetic field pre-sowing seed treatment effects on soybean sugar, protein, nitrogen, hydrogen peroxide (H 2 O 2 ) ascorbic acid (AsA), proline, phenolic and malondialdehyde (MDA) along with chlorophyll contents (Chl "a" "b" and total chlorophyll contents). Specific activities of enzymes such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD) and peroxides (POD) were also assayed. The specific activity of enzymes (during germination and early growth), biochemical and chlorophyll contents were enhanced significantly under the effect of both laser and magnetic pre-sowing treatments. Magnetic field treatment effect was slightly higher than laser treatment except PRT, AMY and ascorbic acid contents. However, both treatments (laser and magnetic field) effects were significantly higher versus control (un-treated seeds). Results revealed that laser and magnetic field pre-sowing seed treatments have potential to enhance soybean biological moieties, chlorophyll contents and metabolically important enzymes (degrade stored food and scavenge reactive oxygen species). Future study should be focused on growth characteristics at later stages and yield attributes. Copyright © 2016 Elsevier B.V. All rights reserved.

Growth of Myxococcus xanthus in continuous-flow-cell bioreactors as a method for studying development.

PubMed

Smaldone, Gregory T; Jin, Yujie; Whitfield, Damion L; Mu, Andrew Y; Wong, Edward C; Wuertz, Stefan; Singer, Mitchell

2014-04-01

Nutrient sensors and developmental timers are two classes of genes vital to the establishment of early development in the social soil bacterium Myxococcus xanthus. The products of these genes trigger and regulate the earliest events that drive the colony from a vegetative state to aggregates, which ultimately leads to the formation of fruiting bodies and the cellular differentiation of the individual cells. In order to more accurately identify the genes and pathways involved in the initiation of this multicellular developmental program in M. xanthus, we adapted a method of growing vegetative populations within a constant controllable environment by using flow cell bioreactors, or flow cells. By establishing an M. xanthus community within a flow cell, we are able to test developmental responses to changes in the environment with fewer concerns for effects due to nutrient depletion or bacterial waste production. This approach allows for greater sensitivity in investigating communal environmental responses, such as nutrient sensing. To demonstrate the versatility of our growth environment, we carried out time-lapse confocal laser scanning microscopy to visualize M. xanthus biofilm growth and fruiting body development, as well as fluorescence staining of exopolysaccharides deposited by biofilms. We also employed the flow cells in a nutrient titration to determine the minimum concentration required to sustain vegetative growth. Our data show that by using a flow cell, M. xanthus can be held in a vegetative growth state at low nutrient concentrations for long periods, and then, by slightly decreasing the nutrient concentration, cells can be allowed to initiate the developmental program.

Combining ground-based measurements and satellite-based spectral vegetation indices to track biomass accumulation in post-fire chaparral

NASA Astrophysics Data System (ADS)

Uyeda, K. A.; Stow, D. A.; Roberts, D. A.; Riggan, P. J.

2015-12-01

Multi-temporal satellite imagery can provide valuable information on patterns of vegetation growth over large spatial extents and long time periods, but corresponding ground-referenced biomass information is often difficult to acquire, especially at an annual scale. In this study, I test the relationship between annual biomass estimated using shrub growth rings and metrics of seasonal growth derived from Moderate Resolution Imaging Spectroradiometer (MODIS) spectral vegetation indices (SVIs) for a small area of southern California chaparral to evaluate the potential for mapping biomass at larger spatial extents. The site had most recently burned in 2002, and annual biomass accumulation measurements were available from years 5 - 11 post-fire. I tested metrics of seasonal growth using six SVIs (Normalized Difference Vegetation Index, Enhanced Vegetation Index, Soil Adjusted Vegetation Index, Normalized Difference Water Index, Normalized Difference Infrared Index 6, and Vegetation Atmospherically Resistant Index). While additional research would be required to determine which of these metrics and SVIs are most promising over larger spatial extents, several of the seasonal growth metrics/ SVI combinations have a very strong relationship with annual biomass, and all SVIs have a strong relationship with annual biomass for at least one of the seasonal growth metrics.

Evaluating Hyperspectral Vegetation Indices for Leaf Area Index Estimation of Oryza sativa L. at Diverse Phenological Stages

PubMed Central

Din, Mairaj; Zheng, Wen; Rashid, Muhammad; Wang, Shanqin; Shi, Zhihua

2017-01-01

Hyperspectral reflectance derived vegetation indices (VIs) are used for non-destructive leaf area index (LAI) monitoring for precise and efficient N nutrition management. This study tested the hypothesis that there is potential for using various hyperspectral VIs for estimating LAI at different growth stages of rice under varying N rates. Hyperspectral reflectance and crop canopy LAI measurements were carried out over 2 years (2015 and 2016) in Meichuan, Hubei, China. Different N fertilization, 0, 45, 82, 127, 165, 210, 247, and 292 kg ha-1, were applied to generate various scales of VIs and LAI values. Regression models were used to perform quantitative analyses between spectral VIs and LAI measured under different phenological stages. In addition, the coefficient of determination and RMSE were employed to evaluate these models. Among the nine VIs, the ratio vegetation index, normalized difference vegetation index (NDVI), modified soil-adjusted vegetation index (MSAVI), modified triangular vegetation index (MTVI2) and exhibited strong and significant relationships with the LAI estimation at different phenological stages. The enhanced vegetation index performed moderately. However, the green normalized vegetation index and blue normalized vegetation index confirmed that there is potential for crop LAI estimation at early phenological stages; the soil-adjusted vegetation index and optimized soil-adjusted vegetation index were more related to the soil optical properties, which were predicted to be the least accurate for LAI estimation. The noise equivalent accounted for the sensitivity of the VIs and MSAVI, MTVI2, and NDVI for the LAI estimation at phenological stages. The results note that LAI at different crop phenological stages has a significant influence on the potential of hyperspectral derived VIs under different N management practices. PMID:28588596

A dynamic growth model of vegetative soya bean plants: model structure and behaviour under varying root temperature and nitrogen concentration

NASA Technical Reports Server (NTRS)

Lim, J. T.; Wilkerson, G. G.; Raper, C. D. Jr; Gold, H. J.

1990-01-01

A differential equation model of vegetative growth of the soya bean plant (Glycine max (L.) Merrill cv. Ransom') was developed to account for plant growth in a phytotron system under variation of root temperature and nitrogen concentration in nutrient solution. The model was tested by comparing model outputs with data from four different experiments. Model predictions agreed fairly well with measured plant performance over a wide range of root temperatures and over a range of nitrogen concentrations in nutrient solution between 0.5 and 10.0 mmol NO3- in the phytotron environment. Sensitivity analyses revealed that the model was most sensitive to changes in parameters relating to carbohydrate concentration in the plant and nitrogen uptake rate.

Dietary protein intake and quality in early life: impact on growth and obesity.

PubMed

Lind, Mads V; Larnkjær, Anni; Mølgaard, Christian; Michaelsen, Kim F

2017-01-01

Obesity is an increasing problem and high-protein intake early in life seems to increase later risk of obesity. This review summarizes recent publications in the area including observational and intervention studies and publications on underlying mechanisms. Recent observational and randomized controlled trials confirmed that high-protein intake in early life seems to increase early weight gain and the risk of later overweight and obesity. Recent studies have looked at the effect of different sources of protein, and especially high-animal protein intake seems to have an effect on obesity. Specific amino acids, such as leucine, have also been implicated in increasing later obesity risk maybe via specific actions on insulin-like growth factor I. Furthermore, additional underlying mechanisms including epigenetics have been linked to long-term obesogenic programming. Finally, infants with catch-up growth or specific genotypes might be particularly vulnerable to high-protein intake. Recent studies confirm the associations between high-protein intake during the first 2 years and later obesity. Furthermore, knowledge of the mechanisms involved and the role of different dietary protein sources and amino acids has increased, but intervention studies are needed to confirm the mechanisms. Avoiding high-protein intake in early life holds promise as a preventive strategy for childhood obesity.

High nutrient-use efficiency during early seedling growth in diverse Grevillea species (Proteaceae)

PubMed Central

He, Tianhua; Fowler, William M.; Causley, Casey L.

2015-01-01

Several hypotheses have been proposed to explain the rich floristic diversity in regions characterised by nutrient-impoverished soils; however, none of these hypotheses have been able to explain the rapid diversification over a relatively short evolutionary time period of Grevillea, an Australian plant genus with 452 recognised species/subspecies and only 11 million years of evolutionary history. Here, we hypothesise that the apparent evolutionary success of Grevillea might have been triggered by the highly efficient use of key nutrients. The nutrient content in the seeds and nutrient-use efficiency during early seedling growth of 12 species of Grevillea were compared with those of 24 species of Hakea, a closely related genus. Compared with Hakea, the Grevillea species achieved similar growth rates (root and shoot length) during the early stages of seedling growth but contained only approximately half of the seed nutrient content. We conclude that the high nutrient-use efficiency observed in Grevillea might have provided a selective advantage in nutrient-poor ecosystems during evolution and that this property likely contributed to the evolutionary success in Grevillea. PMID:26607493

Early vs. asymptotic growth responses of herbaceous plants to elevated CO[sub 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, S.C.; Jasienski, M.; Bazzaz, F.A.

1999-07-01

Although many studies have examined the effects of elevated carbon dioxide on plant growth,'' the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO[sub 2] responses as a single response ratio thus obscures two qualitatively distinct kinds of effects. The present experiment examines effects of elevated CO[sub 2] on both early and asymptotic growth parameters in eight C[sub 3] herbaceous plant species (Abutilon theophrasti, Cassia obtusifolia, Plantago major, Rumex crispus, Taraxacum officinale, Dactylis glomerata, Lolium multiflorum, and Panicummore » dichotomoflorum). Plants were grown for 118--172 d in a factorial design of CO[sub 2] (350 and 700 [micro]L/L) and plant density (individually grown vs. high-density monocultures) under edaphic conditions approximating those of coastal areas in Massachusetts. For Abutilon theophrasti, intraspecific patterns of plant response were also assessed using eight genotypes randomly sampled from a natural population and propagated as inbred lines.« less

Rate of Language Growth in Children with Hearing Loss in an Auditory-Verbal Early Intervention Program

ERIC Educational Resources Information Center

Jackson, Carla Wood; Schatschneider, Christopher

2013-01-01

This longitudinal study explored the rate of language growth of children in an early intervention program providing auditory-verbal therapy. A retrospective investigation, the study applied a linear growth model to estimate a mean growth curve and the extent of individual variation in language performance on the Preschool Language Scale, 4th ed.…

The inhibitory effects of essential oil constituents against germination, outgrowth and vegetative growth of spores of Clostridium perfringens type A in laboratory medium and chicken meat.

PubMed

Alanazi, Saud; Alnoman, Maryam; Banawas, Saeed; Saito, Ryoichi; Sarker, Mahfuzur R

2018-08-01

C. perfringens type A is the causative agent of C. perfringens type A food poisoning (FP) and non-food-borne (NFB) human gastrointestinal diseases. Due to its ability to form highly heat-resistant spores, it is of great interest to develop strategies alternative to thermal processing to inactivate C. perfrinegens. Thus, in this study we evaluated the inhibitory effects of essential oil constituents (EOCs) (cinnamaldehyde, eugenol, allyl isothiocyanate (AITC), and carvacrol) against germination, outgrowth and vegetative growth of spores of C. perfringens FP and NFB disease isolates in laboratory medium and chicken meat. The cinnamaldehyde, eugenol and carvacrol, but not AITC, all at 0.05-0.1%, inhibited the germination of spores of all tested C. perfringens isolates in Tripticase-glucose-yeast extract (TGY) medium. Furthermore, all tested EOCs at 0.05-0.1% arrested the outgrowth and vegetative growth of C. perfringens spores in TGY, with AITC and carvacrol being the most effective. However, among four tested EOCs, only AITC (at 0.5%-2.0%) was able to inhibit the growth of C. perfringens spores in chicken meat and no such inhibitory effect was observed even with a 10-fold higher concentration (5%) of carvacrol. In conclusion, our current work identified AITC as an effective EOC to control spores and vegetative cells of C. perfringens isolates in laboratory medium and chicken meat. Further studies on evaluating the effectiveness of different combination of EOCs against C. perfringens spore growth in different meat products should establish an effective use of EOCs to control the risk of C. perfringens-mediated illnesses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Waterlogging effects on growth and yield components in late-planted soybean.

PubMed

Linkemer, G; Board, J E; Musgrave, M E

1998-01-01

A major agronomic problem in the southeastern USA is low yield of late-planted soybean [Glycine max (L.) Merr.]. This problem is aggravated by the adverse effect of waterlogging on crop growth. Our objectives were to identify soybean growth stages sensitive to waterlogging; identify yield components and physiological parameters explaining yield losses induced by waterlogging; and determine the extent of yield losses induced by waterlogging under natural field conditions. Greenhouse and field studies were conducted during 1993 and 1994 near Baton Rouge, LA, (30 degrees N Lat) on a Commerce silt loam. Waterlogging tolerance was assessed in cultivar Centennial (Maturity Group VI) at three vegetative and five reproductive growth stages by maintaining the water level at the soil surface in a greenhouse study. Using the same cultivar, we evaluated the effect of drainage in the field for late-planted soybean. Rain episodes determined the timing of waterlogging; redox potential and oxygen concentration of the soil were used to quantify the intensity of waterlogging stress. Results of the greenhouse study indicated that the early vegetative period (V2) and the early reproductive stages (R1, R3, and R5) were most sensitive to waterlogging. Three to 5 cm of rain per day falling on poorly drained soil was sufficient to reduce crop growth rate, resulting in a yield decline from 2453 to 1550 kg ha-1. Yield loss in both field and greenhouse studies was induced primarily by decreased pod production resulting from fewer pods per reproductive node. In conclusion, waterlogging was determined to be an important stress for late-planted soybean in high rainfall areas such as the Gulf Coast Region.

Plasticity in reproduction and growth among 52 range-wide populations of a Mediterranean conifer: adaptive responses to environmental stress.

PubMed

Santos-Del-Blanco, L; Bonser, S P; Valladares, F; Chambel, M R; Climent, J

2013-09-01

A plastic response towards enhanced reproduction is expected in stressful environments, but it is assumed to trade off against vegetative growth and efficiency in the use of available resources deployed in reproduction [reproductive efficiency (RE)]. Evidence supporting this expectation is scarce for plants, particularly for long-lived species. Forest trees such as Mediterranean pines provide ideal models to study the adaptive value of allocation to reproduction vs. vegetative growth given their among-population differentiation for adaptive traits and their remarkable capacity to cope with dry and low-fertility environments. We studied 52 range-wide Pinus halepensis populations planted into two environmentally contrasting sites during their initial reproductive stage. We investigated the effect of site, population and their interaction on vegetative growth, threshold size for female reproduction, reproductive-vegetative size relationships and RE. We quantified correlations among traits and environmental variables to identify allocation trade-offs and ecotypic trends. Genetic variation for plasticity was high for vegetative growth, whereas it was nonsignificant for reproduction. Size-corrected reproduction was enhanced in the more stressful site supporting the expectation for adverse conditions to elicit plastic responses in reproductive allometry. However, RE was unrelated with early reproductive investment. Our results followed theoretical predictions and support that phenotypic plasticity for reproduction is adaptive under stressful environments. Considering expectations of increased drought in the Mediterranean, we hypothesize that phenotypic plasticity together with natural selection on reproductive traits will play a relevant role in the future adaptation of forest tree species. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Simulation of wetlands forest vegetation dynamics

USGS Publications Warehouse

Phipps, R.L.

1979-01-01

A computer program, SWAMP, was designed to simulate the effects of flood frequency and depth to water table on southern wetlands forest vegetation dynamics. By incorporating these hydrologic characteristics into the model, forest vegetation and vegetation dynamics can be simulated. The model, based on data from the White River National Wildlife Refuge near De Witt, Arkansas, "grows" individual trees on a 20 x 20-m plot taking into account effects on the tree growth of flooding, depth to water table, shade tolerance, overtopping and crowding, and probability of death and reproduction. A potential application of the model is illustrated with simulations of tree fruit production following flood-control implementation and lumbering. ?? 1979.

Breast Milk Lipidome Is Associated with Early Growth Trajectory in Preterm Infants

PubMed Central

Moyon, Thomas; Antignac, Jean-Philippe; Qannari, El Mostafa; Croyal, Mikaël; Soumah, Mohamed; David-Sochard, Agnès; Billard, Hélène; Legrand, Arnaud; Boscher, Cécile; Darmaun, Dominique; Rozé, Jean-Christophe

2018-01-01

Human milk is recommended for feeding preterm infants. The current pilot study aims to determine whether breast-milk lipidome had any impact on the early growth-pattern of preterm infants fed their own mother’s milk. A prospective-monocentric-observational birth-cohort was established, enrolling 138 preterm infants, who received their own mother’s breast-milk throughout hospital stay. All infants were ranked according to the change in weight Z-score between birth and hospital discharge. Then, we selected infants who experienced “slower” (n = 15, −1.54 ± 0.42 Z-score) or “faster” (n = 11, −0.48 ± 0.19 Z-score) growth; as expected, although groups did not differ regarding gestational age, birth weight Z-score was lower in the “faster-growth” group (0.56 ± 0.72 vs. −1.59 ± 0.96). Liquid chromatography–mass spectrometry lipidomic signatures combined with multivariate analyses made it possible to identify breast-milk lipid species that allowed clear-cut discrimination between groups. Validation of the selected biomarkers was performed using multidimensional statistical, false-discovery-rate and ROC (Receiver Operating Characteristic) tools. Breast-milk associated with faster growth contained more medium-chain saturated fatty acid and sphingomyelin, dihomo-γ-linolenic acid (DGLA)-containing phosphethanolamine, and less oleic acid-containing triglyceride and DGLA-oxylipin. The ability of such biomarkers to predict early-growth was validated in presence of confounding clinical factors but remains to be ascertained in larger cohort studies. PMID:29385065

Modelling the interactions between vegetation and climate from the Cretaceous to the Eocene

NASA Astrophysics Data System (ADS)

Loptson, Claire; Lunt, Dan; Francis, Jane

2013-04-01

The climates during the Cretaceous (~144 to 66 Ma) and the early Eocene (~56 to 48 Ma) were much warmer than the present day. Atmospheric CO2 levels for these past climates have a large uncertainty associated with them, but were possibly as high as 2000 to 3000 ppm for the early Eocene (Beerling and Royer, 2011; Lowenstein and Demicco, 2006) and maximum values are thought to range from 800 to 1800 ppm during the Cretaceous (Royer et al., 2012). Current modelling efforts have had great difficulty in replicating the shallow latitudinal temperature gradient indicated by proxy data for these time periods (e.g. Heinemann et al., 2009; Winguth et al., 2010; Shellito et al., 2009). Mechanisms that can result in such a low temperature gradient have not been found (Winguth et al., 2010; Beerling et al., 2011; Sloan and Morrill, 1998), but a contributing factor could be that not all climate feedbacks are included in these models. Vegetation feedbacks have been shown to be especially important (e.g. Otto-Bliesner and Upchurch, 1997; Bonan, 2008) so by including a more accurate representation of vegetation in the climate model, the model-data discrepancies may be reduced. A fully coupled atmosphere-ocean GCM, HadCM3L, coupled to a dynamic global vegetation model (TRIFFID), was used to simulate the climate and the predicted vegetation distributions for and the early Eocene and 12 different time slices representing different ages throughout the Cretaceous at 4x pre-industrial CO2. The only difference in the way these simulations were set up are different boundary conditions that are specific to that time period, e.g. different solar constants and paleogeographies. This allows a direct comparison between the time slices. We present the changes in climate, and therefore vegetation, during the Cretaceous due to changes in these boundary conditions alone, with a focus on Antarctica. Additional Eocene simulations were also carried out with a) fixed globally-uniform vegetation and b

Learning to eat vegetables in early life: the role of timing, age and individual eating traits.

PubMed

Caton, Samantha J; Blundell, Pam; Ahern, Sara M; Nekitsing, Chandani; Olsen, Annemarie; Møller, Per; Hausner, Helene; Remy, Eloïse; Nicklaus, Sophie; Chabanet, Claire; Issanchou, Sylvie; Hetherington, Marion M

2014-01-01

Vegetable intake is generally low among children, who appear to be especially fussy during the pre-school years. Repeated exposure is known to enhance intake of a novel vegetable in early life but individual differences in response to familiarisation have emerged from recent studies. In order to understand the factors which predict different responses to repeated exposure, data from the same experiment conducted in three groups of children from three countries (n = 332) aged 4-38 m (18.9±9.9 m) were combined and modelled. During the intervention period each child was given between 5 and 10 exposures to a novel vegetable (artichoke puree) in one of three versions (basic, sweet or added energy). Intake of basic artichoke puree was measured both before and after the exposure period. Overall, younger children consumed more artichoke than older children. Four distinct patterns of eating behaviour during the exposure period were defined. Most children were "learners" (40%) who increased intake over time. 21% consumed more than 75% of what was offered each time and were labelled "plate-clearers". 16% were considered "non-eaters" eating less than 10 g by the 5th exposure and the remainder were classified as "others" (23%) since their pattern was highly variable. Age was a significant predictor of eating pattern, with older pre-school children more likely to be non-eaters. Plate-clearers had higher enjoyment of food and lower satiety responsiveness than non-eaters who scored highest on food fussiness. Children in the added energy condition showed the smallest change in intake over time, compared to those in the basic or sweetened artichoke condition. Clearly whilst repeated exposure familiarises children with a novel food, alternative strategies that focus on encouraging initial tastes of the target food might be needed for the fussier and older pre-school children.

A critical review on effects, tolerance mechanisms and management of cadmium in vegetables.

PubMed

Rizwan, Muhammad; Ali, Shafaqat; Adrees, Muhammad; Ibrahim, Muhammad; Tsang, Daniel C W; Zia-Ur-Rehman, Muhammad; Zahir, Zahir Ahmad; Rinklebe, Jörg; Tack, Filip M G; Ok, Yong Sik

2017-09-01

Cadmium (Cd) accumulation in vegetables is an important environmental issue that threatens human health globally. Understanding the response of vegetables to Cd stress and applying management strategies may help to reduce the Cd uptake by vegetables. The aim of the present review is to summarize the knowledge concerning the uptake and toxic effects of Cd in vegetables and the different management strategies to combat Cd stress in vegetables. Leafy vegetables grown in Cd contaminated soils potentially accumulate higher concentrations of Cd, posing a threat to food commodities. The Cd toxicity decreases seed germination, growth, biomass and quality of vegetables. This reduces the photosynthesis, stomatal conductance and alteration in mineral nutrition. Toxicity of Cd toxicity also interferes with vegetable biochemistry causing oxidative stress and resulting in decreased antioxidant enzyme activities. Several management options have been employed for the reduction of Cd uptake and toxicity in vegetables. The exogenous application of plant growth regulators, proper mineral nutrition, and the use of organic and inorganic amendments might be useful for reducing Cd toxicity in vegetables. The use of low Cd accumulating vegetable cultivars in conjunction with insolubilizing amendments and proper agricultural practices might be a useful technique for reducing Cd exposure in the food chain. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variability of Pinus halepensis Mill. Essential Oils and Their Antioxidant Activities Depending on the Stage of Growth During Vegetative Cycle.

PubMed

Djerrad, Zineb; Djouahri, Abderrahmane; Kadik, Leila

2017-04-01

The impact of growth stages during vegetative cycle (B 0  - B 5 ) on chemical composition and antioxidant activities of Pinus halepensis Mill. needles essential oils was investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α-pinene (8.5 - 12.9%), myrcene (17.5 - 21.6%), p-cymene (7.9 - 11.9%) and (Z)-β-caryophyllene (17.3 - 21.2%) as major components, decreased from 88.9% at B 0 growth stage to 66.9% at B 5 growth stage, whereas oxygenated derivatives, represented by caryophyllene oxide (5.4 - 12.6%) and terpinen-4-ol (0.4 - 3.3%) as major components, increased from 7% at B 0 growth stage to 28.4% at B 5 growth stage. Furthermore, our findings showed that essential oil of P. halepensis needles collected at B 5 growth stage possess higher antioxidant activities by four different testing systems than those collected at B 0  - B 4 growth stages. This highlighted variability led to conclude that we should select essential oils to be investigated carefully depending on growth stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Probabilistic Evaluation of Anthropogenic Regulations In a Vegetated River Channel Using a Vegetation Dynamics Modeling

NASA Astrophysics Data System (ADS)

Miyamoto, Hitoshi

2015-04-01

Vegetation overgrowth in fluvial floodplains, gravel beds, and sand bars has been a serious engineering problem for riparian management in Japan. From the viewpoints of flood control and ecological conservation, it would be necessary to predict the vegetation dynamics accurately for long-term duration. In this research, we have developed a stochastic model for predicting the vegetation dynamics in fluvial floodplains with emphasis on the interaction with flood impacts. The model consists of the following four components: (i) long-term stochastic behavior of flow discharge, (ii) hydrodynamics in a channel with floodplain vegetation, (iii) variation of riverbed topography, and (iv) vegetation dynamics on floodplains. In the vegetation dynamics model, the flood discharge (i) is stochastically simulated using a filtered Poisson process, one of the conventional approaches in hydrological time-series generation. The component for vegetation dynamics (iv) includes the effects of tree growth, mortality by floods, and infant tree recruitment. Vegetation condition has been observed mainly before and after floods since 2008 at a field site located between 23-24 km from the river mouth in Kako River, Japan. The Kako River has the catchment area of 1,730 km2 and the main channel length of 96 km. This site is one of the vegetation overgrowth sites in the Kako River floodplains. The predominant tree species are willows and bamboos. In the field survey, the position, trunk diameter and height of each tree as well as the riverbed materials were measured after several flood events to investigate their impacts on the floodplain vegetation community. This presentation tries to examine effects of anthropogenic river regulations, i.e., thinning and cutting-down, in the vegetated channel in Kako River by using the vegetation dynamics model. Sensitivity of both the flood water level and the vegetation status in the channel is statistically evaluated in terms of the different cutting

Study on gametophyte vegetative growth of Undaria pinnatifida and its applications

NASA Astrophysics Data System (ADS)

Pang, Shao-Jun; Wu, Chao-Yuan

1996-09-01

When cultured under certain environmental conditions (25°C, light intensity 80 μmol/m2·s, LD 12/12, in enriched seawater medium with 7×10-4 mol/L NO3-N, 1.56×10-4 mol/L, PO4-P and supplements of other elements like Mn, Fe, I, etc.), male and female gametophytes of U. pinnatifida kept growing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. The empirical formula G m= G o·3m was established to estimate the output of vegetative gametophytes. Vigorous vegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, when the temperature was lower than 25°C and other environmental factors were kept optimal. The sufficient supply of gametophyte cells provided enough seeds for raising Undaria sporelings on production scale. Controlled cross-breeding experiments using selected male and female gametophyte clones which increase their cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes from the cross-breeding had almost the same length and width increase rates as those of the control. The fact that vegetative gametophytes can be purposely selected, propagated quickly, cross-bred, with the resulting sporophytes having almost the same characteristics leads to a new way to select desired Undaria strains for long time use without losing the desired economic characteristics.

Survival, growth, and body residues of Hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms

USDA-ARS?s Scientific Manuscript database

We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g-1) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fip...

Assessing the Effects of Soil Humic and Fulvic Acids on Germination and Early Growth of Native and Introduced Grass Varieties

DTIC Science & Technology

2007-01-15

period (8 months) research plans are the following: (a) Germination and early growth experiments of the three remaining combinations by two of the...remainder of the contract period (8 months) research plans are the following: (a) Germination and early growth experiments of the three remaining... GROWTH OF NATIVE AND INTRODUCED GRASS VARIETIES NAME OF PRINCIPAL INVESTIGATOR: SENESI NICOLA-PROFESSOR NAME OF CONTRACTOR: UNIVERSITA’ DI BARI

Effect of insulin-like growth factor-I during the early postnatal period in intrauterine growth-restricted rats.

PubMed

Ikeda, Naho; Shoji, Hiromichi; Suganuma, Hiroki; Ohkawa, Natsuki; Kantake, Masato; Murano, Yayoi; Sakuraya, Koji; Shimizu, Toshiaki

2016-05-01

Insulin-like growth factor-I (IGF-I) is essential for perinatal growth and development; low serum IGF-I has been observed during intrauterine growth restriction (IUGR). We investigated the effects of recombinant human (rh) IGF-I in IUGR rats during the early postnatal period. Intrauterine growth restriction was induced by bilateral uterine artery ligation in pregnant rats. IUGR pups were divided into two groups injected daily with rhIGF-I (2 mg/kg; IUGR/IGF-I, n = 16) or saline (IUGR/physiologic saline solution (PSS), n = 16) from postnatal day (PND) 7 to 13. Maternal sham-operated pups injected with saline were used as controls (control, n = 16). Serum IGF-I and IGF binding proteins (IGFBP) 3 and 5 were measured on PND25. The expression of Igf-i, IGF-I receptor (Igf-ir), Igfbp3, and 5 mRNA in the liver and brain was measured using real-time polymerase chain reaction on PND25. Immunohistochemical staining of the liver for IGF expression was performed. Mean bodyweight on PND3 and PND25 in the IUGR pups (IUGR/IGF-I and IUGR/PSS) was significantly lower than that of the control pups. Serum IGF-I and hepatic Igf-ir mRNA in the IUGR pups were significantly lower than those in the control pups. In the IUGR/IGF-I group, hepatic Igfbp3 mRNA and liver immunohistochemical staining were increased. In the IUGR/PSS and control pups, there were no significant differences between these two groups in serum IGFBP3 and IGFBP5, hepatic Igf-i and Igfbp-5 mRNA, or brain Igf mRNA. No benefits on body and brain weight gain but an effective increase in hepatic IGFBP-3 was observed after treatment with 2 mg/kg rhIGF-I during the early postnatal period. © 2015 Japan Pediatric Society.

A Longitudinal Assessment of Early Acceleration of Students in Mathematics on Growth in Mathematics Achievement

ERIC Educational Resources Information Center

Ma, X.

2005-01-01

Early acceleration of students in mathematics (in the form of early access to formal abstract algebra) has been a controversial educational issue. The current study examined the rate of growth in mathematics achievement of accelerated gifted, honors, and regular students across the entire secondary years (Grades 7-12), in comparison to their…

Potential for early warning of maalria in India using NOAA-AVHRR based vegetation health indices

NASA Astrophysics Data System (ADS)

Dhiman, R. C.; Kogan, Felix; Singh, Neeru; Singh, R. P.; Dash, A. P.

Malaria is still a major public health problem in India with about 1 82 million cases annually and 1000 deaths As per World Health Organization WHO estimates about 1 3 million Disability Adjusted Life Years DALYs are lost annually due to malaria in India Central peninsular region of India is prone to malaria outbreaks Meteorological parameters changes in ecological conditions development of resistance in mosquito vectors development of resistance in Plasmodium falciparum parasite and lack of surveillance are the likely reasons of outbreaks Based on satellite data and climatic factors efforts have been made to develop Early Warning System EWS in Africa but there is no headway in this regard in India In order to find out the potential of NOAA satellite AVHRR derived Vegetation Condition Index VCI Temperature Condition Index TCI and a cumulative indicator Vegetation Health Index VHI were attempted to find out their potential for development of EWS Studies were initiated by analysing epidemiological data of malaria vis-a-vis VCI TCI and VHI from Bikaner and Jaisalmer districts of Rajasthan and Tumkur and Raichur districts of Karnataka Correlation coefficients between VCI and monthly malaria cases for epidemic years were computed Positive correlation 0 67 has been found with one-month lag between VCI and malaria incidence in respect of Tumkur while a negative correlation with TCI -0 45 is observed In Bikaner VCI is found to be negatively related -0 71 with malaria cases in epidemic year of 1994 Weekly

Plant Growth Research for Food Production: Development and Testing of Expandable Tuber Growth Module

NASA Technical Reports Server (NTRS)

Cordova, Brennan A.

2017-01-01

Controlled and reliable growth of a variety of vegetable crops is an important capability for manned deep space exploration systems for providing nutritional supplementation and psychological benefits to crew members. Because current systems have been limited to leafy vegetables that require minimal root space, a major goal for these systems is to increase their ability to grow new types of crops, including tuber plants and root vegetables that require a large root space. An expandable root zone module and housing was developed to integrate this capability into the Vegetable Production System (Veggie). The expandable module uses a waterproof, gas-permeable bag with a structure that allows for root space to increase vertically throughout the growth cycle to accommodate for expanding tuber growth, while minimizing the required media mass. Daikon radishes were chosen as an ideal tuber crop for their subterraneous tuber size and rapid growth cycle, and investigations were done to study expanding superabsorbent hydrogels as a potential growth media. These studies showed improved water retention, but restricted oxygen availability to roots with pure gel media. It was determined that these hydrogels could be integrated in lower proportions into standard soil to achieve media expansion and water retention desired. Using the constructed module prototype and ideal gel and soil media mixture, daikon radishes are being grown in the system to test the capability and success of the system through a full growth cycle.

Growth recovery and faltering through early adolescence in low- and middle-income countries: Determinants and implications for cognitive development.

PubMed

Georgiadis, Andreas; Benny, Liza; Duc, Le Thuc; Galab, Sheikh; Reddy, Prudhvikar; Woldehanna, Tassew

2017-04-01

Child chronic undernutrition, as measured by stunting, is prevalent in low- and middle-income countries and is among the major threats to child development. While stunting and its implications for cognitive development have been considered irreversible beyond early childhood there is a lack of consensus in the literature on this, as there is some evidence of recovery from stunting and that this recovery may be associated with improvements in cognition. Less is known however, about the drivers of growth recovery and the aspects of recovery linked to cognitive development. In this paper we investigate the factors associated with growth recovery and faltering through age 12 years and the implications of the incidence, timing, and persistence of post-infancy recovery from stunting for cognitive development using longitudinal data from Ethiopia, India, Peru, and Vietnam. We find that the factors most systematically associated with accelerated growth both before and after early childhood and across countries include mother's height, household living standards and shocks, community wages, food prices, and garbage collection. Our results suggest that post-infancy recovery from stunting is more likely to be systematically associated with higher achievement scores across countries when it is persistent and that associations between growth trajectories and cognitive achievement in middle childhood do not persist through early adolescence across countries. Overall, our findings indicate that growth after early childhood is responsive to changes in the household and community environments and that growth promotion after early childhood may yield improvements in child cognitive development. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Grass control improves early growth of black walnut more than either deep ripping or irrigation

Treesearch

J.W. Van Sambeek; F.D. McBride

1991-01-01

Chemical control of a tall fescue sod (Festuca arundinacea Schreb.) using glyphosate and simazine improved early tree growth of black walnut (Juglans nigra L.) more than either deep ripping or irrigation on an upland old field site in southern Illinois. Growth of trees with irrigation and grass control was less than with grass...

Early cretaceous topographic growth of the Lhasaplano, Tibetan plateau: Constraints from the Damxung conglomerate

NASA Astrophysics Data System (ADS)

Wang, Jian-Gang; Hu, Xiumian; Garzanti, Eduardo; Ji, Wei-Qiang; Liu, Zhi-Chao; Liu, Xiao-Chi; Wu, Fu-Yuan

2017-07-01

Constraining the timing of early topographic growth on the Tibetan plateau is critical for any models of India-Asia collision, Himalayan orogeny and subsequent plateau development in the Cenozoic. Stratigraphic, sedimentological and provenance analysis of the Lower Cretaceous red-beds of the Damxung Conglomerate provide new key information to reconstruct the paleogeography and the tectonic evolution of the Lhasa terrane at the time. The over 700-m-thick Damxung Conglomerate documents distal alluvial fan to braidplain sedimentation passing upward to proximal alluvial fan sedimentation. Deposition began near sea level, as documented by limestone beds occurring at the base of the unit. Zircon U-Pb dating of interbedded tuff layers constrain deposition age at ca. 111 Ma. Abundance of volcanic clasts, Cretaceous U-Pb ages and Hf isotopes of detrital zircons yielding mainly negative ɛHf(t) values together with paleocurrent data indicate an active volcanic source located in the North Lhasa subterrane. Pre-Mesozoic-aged zircon, recycled quartz and (meta) sedimentary rock fragments increase up-section, indicating progressive erosional exhumation of the Paleozoic sedimentary/metasedimentary basement. The Damxung Conglomerate thus records a significant uplift and unroofing stage in the source region, implying initial topographic growth on the Lhasa terrane at early Albian time. Early Cretaceous topographic growth on the Lhasa terrane is supported by the stratigraphic record in the Linzhou basin, the Xigaze forearc basin and the southern Nima basin. In contrast, marine strata in the central-western Lhasa terrane lasted until the early Cenomanian (ca. 96 Ma), indicating diachronous marine regression on the Lhasa terrane from east to west.

Mass and size growth of early-type galaxies by dry mergers in cluster environments

NASA Astrophysics Data System (ADS)

Oogi, Taira; Habe, Asao; Ishiyama, Tomoaki

2016-02-01

We perform dry merger simulations to investigate the role of dry mergers in the size growth of early-type galaxies in high-density environments. We replace the virialized dark matter haloes obtained by a large cosmological N-body simulation with N-body galaxy models consisting of two components, a stellar bulge and a dark matter halo, which have higher mass resolution than the cosmological simulation. We then resimulate nine cluster-forming regions, whose masses range from 1 × 1014 to 5 × 1014 M⊙. Masses and sizes of stellar bulges are also assumed to satisfy the stellar mass-size relation of high-z compact massive early-type galaxies. We find that dry major mergers considerably contribute to the mass and size growth of central massive galaxies. One or two dry major mergers double the average stellar mass and quadruple the average size between z = 2 and 0. These growths favourably agree with observations. Moreover, the density distributions of our simulated central massive galaxies grow from the inside-out, which is consistent with recent observations. The mass-size evolution is approximated as R∝ M_{{ast }}^{α }, with α ˜ 2.24. Most of our simulated galaxies are efficiently grown by dry mergers, and their stellar mass-size relations match the ones observed in the local Universe. Our results show that the central galaxies in the cluster haloes are potential descendants of high-z (z ˜ 2-3) compact massive early-type galaxies. This conclusion is consistent with previous numerical studies which investigate the formation and evolution of compact massive early-type galaxies.

Seasonally asymmetric enhancement of northern vegetation productivity

NASA Astrophysics Data System (ADS)

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.

Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

PubMed

Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

2017-09-01

Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

Blend Sign on Computed Tomography: Novel and Reliable Predictor for Early Hematoma Growth in Patients With Intracerebral Hemorrhage.

PubMed

Li, Qi; Zhang, Gang; Huang, Yuan-Jun; Dong, Mei-Xue; Lv, Fa-Jin; Wei, Xiao; Chen, Jian-Jun; Zhang, Li-Juan; Qin, Xin-Yue; Xie, Peng

2015-08-01

Early hematoma growth is not uncommon in patients with intracerebral hemorrhage and is an independent predictor of poor functional outcome. The purpose of our study was to report and validate the use of our newly identified computed tomographic (CT) blend sign in predicting early hematoma growth. Patients with intracerebral hemorrhage who underwent baseline CT scan within 6 hours after onset of symptoms were included. The follow-up CT scan was performed within 24 hours after the baseline CT scan. Significant hematoma growth was defined as an increase in hematoma volume of >33% or an absolute increase of hematoma volume of >12.5 mL. The blend sign on admission nonenhanced CT was defined as blending of hypoattenuating area and hyperattenuating region with a well-defined margin. Univariate and multivariable logistic regression analyses were performed to assess the relationship between the presence of the blend sign on nonenhanced admission CT and early hematoma growth. A total of 172 patients were included in our study. Blend sign was observed in 29 of 172 (16.9%) patients with intracerebral hemorrhage on baseline nonenhanced CT scan. Of the 61 patients with hematoma growth, 24 (39.3%) had blend sign on admission CT scan. Interobserver agreement for identifying blend sign was excellent between the 2 readers (κ=0.957). The multivariate logistic regression analysis demonstrated that the time to baseline CT scan, initial hematoma volume, and presence of blend sign on baseline CT scan to be independent predictors of early hematoma growth. The sensitivity, specificity, positive and negative predictive values of blend sign for predicting hematoma growth were 39.3%, 95.5%, 82.7%, and 74.1%, respectively. The CT blend sign could be easily identified on regular nonenhanced CT and is highly specific for predicting hematoma growth. © 2015 American Heart Association, Inc.

Early release improves long-term growth and development of direct-seeded nuttall oak saplings

Treesearch

James S. Meadows; Robert L. Johnson; Roger M. Krinard

2015-01-01

Early growth of bottomland oaks is typically slow, and many oaks eventually become overtopped by trees of other species. Removal of these larger competitors in a young stand might improve growth of the oaks and lead to more free-to-grow oaks as the stand matures. Release treatments were applied in 1980 to an 11-year-old, direct-seeded Nuttall oak (Quercus texana Buckl...

Growth in early life and the development of obesity by age 9 years: are there critical periods and a role for an early life stressor?

PubMed

Giles, L C; Whitrow, M J; Rumbold, A R; Davies, C E; de Stavola, B; Pitcher, J B; Davies, M J; Moore, V M

2013-04-01

Rapid growth, possibly occurring in critical periods in early life, may be important for the development of obesity. It is unknown whether this is influenced by postnatal exposures such as age-relevant sources of stress. Frequent house moves may be one such stressor. We aimed to examine if there is a period of growth in early life critical for the development of child obesity by age 9 years and assess the role of house moves in modifying any relationships between early life growth and obesity at age 9 years. Prospective Australian birth cohort study. In all, 392 children with serial body size measurements from birth to age 9 years. Standardized body mass index (z-BMI) was available for six time points (spanning birth to 3½ years), and the total number of house moves between birth and 3½ years. The outcomes considered were z-BMI and % body fat (%BF) at age 9 years. Linear regression models were used to estimate the effects of serial measurements of z-BMI and number of house moves on the outcomes. Life-course plots showed that z-BMI at 3½ years was a statistically significant predictor of z-BMI at 9 years (β=0.80; standard error (s.e.), 0.04), whereas z-BMI at 9 months (β=-1.13; s.e., 0.40) and 3½ years (β=4.82; s.e., 0.42) were significant predictors of %BF at age 9 years. There were statistically significant interactions between the number of house moves and change in z-BMI between 9 and 12 months, such that ≥ 3 house moves in early life amplified the detrimental effects of earlier rapid growth on both body size and composition at age 9 years. In the absence of evidence for a single critical period, efforts to prevent overweight and obesity are required throughout childhood. In addition, modifiable postnatal stressors may exacerbate effects of early growth on obesity in later childhood.

Self-Replication of Localized Vegetation Patches in Scarce Environments

PubMed Central

Bordeu, Ignacio; Clerc, Marcel G.; Couteron, Piere; Lefever, René; Tlidi, Mustapha

2016-01-01

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora—and fauna within—or even make use of scarce resources soils. In this paper, we study a robust phenomena observed in semi-arid ecosystems, by which localized vegetation patches split in a process called self-replication. Localized patches of vegetation are visible in nature at various spatial scales. Even though they have been described in literature, their growth mechanisms remain largely unexplored. Here, we develop an innovative statistical analysis based on real field observations to show that patches may exhibit deformation and splitting. This growth mechanism is opposite to the desertification since it allows to repopulate territories devoid of vegetation. We investigate these aspects by characterizing quantitatively, with a simple mathematical model, a new class of instabilities that lead to the self-replication phenomenon observed. PMID:27650430

Self-Replication of Localized Vegetation Patches in Scarce Environments

NASA Astrophysics Data System (ADS)

Bordeu, Ignacio; Clerc, Marcel G.; Couteron, Piere; Lefever, René; Tlidi, Mustapha

2016-09-01

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora—and fauna within—or even make use of scarce resources soils. In this paper, we study a robust phenomena observed in semi-arid ecosystems, by which localized vegetation patches split in a process called self-replication. Localized patches of vegetation are visible in nature at various spatial scales. Even though they have been described in literature, their growth mechanisms remain largely unexplored. Here, we develop an innovative statistical analysis based on real field observations to show that patches may exhibit deformation and splitting. This growth mechanism is opposite to the desertification since it allows to repopulate territories devoid of vegetation. We investigate these aspects by characterizing quantitatively, with a simple mathematical model, a new class of instabilities that lead to the self-replication phenomenon observed.

Dietary nucleotides and early growth in formula-fed infants: a randomized controlled trial.

PubMed

Singhal, Atul; Kennedy, Kathy; Lanigan, J; Clough, Helen; Jenkins, Wendy; Elias-Jones, Alun; Stephenson, Terrence; Dudek, Peter; Lucas, Alan

2010-10-01

Dietary nucleotides are nonprotein nitrogenous compounds that are found in high concentrations in breast milk and are thought to be conditionally essential nutrients in infancy. A high nucleotide intake has been suggested to explain some of the benefits of breastfeeding compared with formula feeding and to promote infant growth. However, relatively few large-scale randomized trials have tested this hypothesis in healthy infants. We tested the hypothesis that nucleotide supplementation of formula benefits early infant growth. Occipitofrontal head circumference, weight, and length were assessed in infants who were randomly assigned to groups fed nucleotide-supplemented (31 mg/L; n=100) or control formula without nucleotide supplementation (n=100) from birth to the age of 20 weeks, and in infants who were breastfed (reference group; n=101). Infants fed with nucleotide-supplemented formula had greater occipitofrontal head circumference at ages 8, 16, and 20 weeks than infants fed control formula (mean difference in z scores at 8 weeks: 0.4 [95% confidence interval: 0.1-0.7]; P=.006) even after adjustment for potential confounding factors (P=.002). Weight at 8 weeks and the increase in both occipitofrontal head circumference and weight from birth to 8 weeks were also greater in infants fed nucleotide-supplemented formula than in those fed control formula. Our data support the hypothesis that nucleotide supplementation leads to increased weight gain and head growth in formula-fed infants. Therefore, nucleotides could be conditionally essential for optimal infant growth in some formula-fed populations. Additional research is needed to test the hypothesis that the benefits of nucleotide supplementation for early head growth, a critical period for brain growth, have advantages for long-term cognitive development.

Growth of and toxin production by nonproteolytic Clostridium botulinum in cooked puréed vegetables at refrigeration temperatures.

PubMed Central

Carlin, F; Peck, M W

1996-01-01

Seven strains of nonproteolytic Clostridium botulinum (types B, E, and F) were each inoculated into a range of anaerobic cooked puréed vegetables. After incubation at 10 degrees C for 15 to 60 days, all seven strains formed toxin in mushrooms, five did so in broccoli, four did so in cauliflower, three did so in asparagus, and one did so in kale. Growth kinetics of nonproteolytic C. botulinum type B in cooked mushrooms, cauliflower, and potatoes were determined at 16, 10, 8, and 5 degrees C. Growth and toxin production occurred in cooked cauliflower and mushrooms at all temperatures and in potatoes at 16 and 8 degrees C. The C. botulinum neurotoxin was detected within 3 to 5 days at 16 degrees C, 11 to 13 days at 10 degrees C, 10 to 34 days at 8 degrees C, and 17 to 20 days at 5 degrees C. PMID:8702303

Metabolic effects of growth factors and polycyclic aromatic hydrocarbons on cultured human placental cells of early and late gestation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guyda, H.J.

1991-03-01

The metabolic effects of epidermal growth factor (EGF), insulin, insulin-like growth factor-I (IGF-I), and IGF-II were determined on human placental cells in monolayer culture obtained from early gestation (less than 20 weeks) and late gestation (38-42 weeks). Parameters studied were uptake of aminoisobutyric acid (AIB), uptake of 3-O-methylglucose and (3H)thymidine incorporation into cell protein. Since benzo(alpha)pyrene (BP) inhibits EGF binding and autophosphorylation in cultured human placental cells, particularly in early gestation, we also studied the effect of benzo(alpha)pyrene and other polycyclic aromatic hydrocarbons (PAHs) on EGF-mediated AIB uptake. The metabolic effects of EGF, insulin, and the IGFs in cultured humanmore » placental cells varied with gestational age and the growth factor studied. All three classes of growth factors stimulated AIB uptake in both early and late gestation at concentrations from 10-100 micrograms/L, well within a physiological range. However, insulin stimulation of AIB uptake was maximal at a high concentration in both early and late gestation cells, suggesting an action via type 1 IGF receptors rather than via insulin receptors. EGF stimulated 3-O-methylglucose uptake only in term placental cells. No significant stimulation of (3H)thymidine incorporation by any of the growth factors tested was seen with either early or late gestation cells. The effect of PAHs on AIB uptake by cultured placental cells was variable. BP alone stimulated AIB uptake by both very early and late gestation cells and enhanced EGF-stimulated AIB uptake. alpha-naphthoflavone alone inhibited AIB uptake at all gestational ages and inhibited EGF-stimulated AIB uptake. beta-Naphthoflavone and 3-methylcholanthrene minimally inhibited AIB uptake by early gestation cells and did not modify EGF-stimulated uptake at any gestational period.« less

Short-term bryoid and vascular vegetation response to reforestation alternatives following wildfire in conifer plantations

Treesearch

Lori J. Kayes; Klaus J. Puettmann; Paul D. Anderson

2011-01-01

How are dynamics of early-seral post-fire vascular plant and bryoid (terrestrial mosses, lichens, and fungi) vegetation impacted by reforestation activities, particularly manual vegetation removal and planting density? Does the relationship between vegetation dynamics and vegetation removal differ between harsh (west-facing) and moderate (east-facing) aspects?...

Ecological investigations: vegetation studies, preliminary findings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olgeirson, E.R.; Martin, R.B.

1978-09-01

The objective of the vegetation studies conducted on the research site is to produce a descriptive data base that can be applied to determinations of carrying capacity of the site and surrounding area. Additional information obtained about parameters that influence vegetation growth and maintenance of soil nutrients, and moisture and temperature regimes help define dynamic relationships that must be understood to effect successful revegetation and habitat rehabilitation. The descriptive vegetation baseline also provides a point of departure for design of future monitoring programs, and predictive models and strategies to be used in dealing with impact mitigation; in turn, monitoring programsmore » and predictive modeling form the bases for making distinctions between natural trends and man-induced perturbations.« less

Re-evaluating the Glacial Vegetation of the Southern Levant and Early Signs of Human Impact on the Environment

NASA Astrophysics Data System (ADS)

Miebach, A.; Chen, C.; Litt, T.

2017-12-01

Assessing paleoenvironmental conditions is crucial to understand the history of modern humans. The southern Levant functioned as a corridor for human migration processes such as the colonization of Europe and the spread of agriculture. Despite its important role in human history, the Levantine paleoenvironment is still insufficiently investigated. In particular, current reconstructions of the paleovegetation are grounded on poor data bases. Here, we revise former hypotheses about the paleovegetation of the southern Levant during the last glacial based on new palynological results from the Sea of Galilee and the Dead Sea. We further evaluate early signs of anthropogenic influences in the Dead Sea catchment by combining evidence of pollen, micro-charcoal, and spores. The palynological results suggest that drought-adapted herbs, dwarf shrubs, and grasses prevailed in the southern Levant during the last glacial. In contrast to the Holocene, there was no belt of continuous and dense Mediterranean vegetation surrounding the Sea of Galilee during MIS 2. Mediterranean elements such as deciduous oaks only occurred in limited amounts and were probably patchily distributed in the whole study area. The vegetation and moisture gradient was not as strong as today. Since the Lateglacial, the Dead Sea region witnessed several rapid environmental changes. Phases with considerably reduced woodland density, increased fire activity, and enhanced catchment erosion occurred. Although climatic triggers were possible, there is a strong indication of anthropogenic influences due to overall increasing human activities in the region. The study gains new insights into environmental responses of the southern Levant to climate variations in the past. It also contributes towards our understanding of human-environmental interactions during the early Holocene.

Differences between WHO AND CDC early growth measurements in the assessment of Cystic Fibrosis clinical outcomes.

PubMed

Usatin, Danielle; Yen, Elizabeth H; McDonald, Catherine; Asfour, Fadi; Pohl, John; Robson, Jacob

2017-07-01

Early childhood growth status has been used to predict long-term clinical outcomes in Cystic Fibrosis (CF) patients. Adulthood CF outcomes based on early weight-for-length (WFL) measurements, using either World Health Organization (WHO) or Centers for Disease Control (CDC) scales, have not been compared. Cystic Fibrosis Foundation registry patients were studied (n=3014). Participants were categorized at age two years as WFL <50th percentile on both WHO and CDC scales, ≥50th percentile on WHO but not CDC, or ≥50th percentile on both. Pulmonary function and overall survival were assessed at age 18years. Stepwise gains in pulmonary function and lung transplant-free survival were noted across the three increasing WFL categories. Children with CF who achieve higher WFL at age two years have improved pulmonary and survival outcomes into adulthood. CF providers should continue to utilize current early growth recommendations, with goal WFL ≥50th percentile on CDC growth charts before age two. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Wheat growth monitoring with radar vegetation indices

USDA-ARS?s Scientific Manuscript database

Microwave remote sensing can help in the monitoring of crop growth. Many experiments have been carried out to investigate the sensitivity of microwave sensors to crop growth parameters. These have clearly shown that canopy structure and water content can greatly affect the measurements. For agricult...

Accuracy and equivalence testing of crown ratio models and assessment of their impact on diameter growth and basal area increment predictions of two variants of the Forest Vegetation Simulator

Treesearch

Laura P. Leites; Andrew P. Robinson; Nicholas L. Crookston

2009-01-01

Diameter growth (DG) equations in many existing forest growth and yield models use tree crown ratio (CR) as a predictor variable. Where CR is not measured, it is estimated from other measured variables. We evaluated CR estimation accuracy for the models in two Forest Vegetation Simulator variants: the exponential and the logistic CR models used in the North...

Ursodeoxycholic Acid Inhibits Clostridium difficile Spore Germination and Vegetative Growth, and Prevents the Recurrence of Ileal Pouchitis Associated With the Infection.

PubMed

Weingarden, Alexa R; Chen, Chi; Zhang, Ningning; Graiziger, Carolyn T; Dosa, Peter I; Steer, Clifford J; Shaughnessy, Megan K; Johnson, James R; Sadowsky, Michael J; Khoruts, Alexander

2016-09-01

To test whether ursodeoxycholic acid (UDCA) is inhibitory to Clostridium difficile and can be used in the treatment of C. difficile-associated ileal pouchitis. The restoration of secondary bile metabolism may be the key mechanism for fecal microbiota transplantation (FMT) in treating recurrent C. difficile infections (RCDI). Therefore, it is possible that exogenous administration of inhibitory bile acids may be used directly as nonantibiotic therapeutics for this indication. The need for such a treatment alternative is especially significant in patients with refractory C. difficile-associated pouchitis, where the efficacy of FMT may be limited. We measured the ability of UDCA to suppress the germination and the vegetative growth of 11 clinical isolate strains of C. difficile from patients treated with FMT for RCDI. In addition, we used oral UDCA to treat a patient with RCDI pouchitis that proved refractory to multiple antibiotic treatments and FMT. UDCA was found to be inhibitory to the germination and the vegetative growth of all C. difficile strains tested. Fecal concentrations of UDCA from the patient with RCDI pouchitis exceeded levels necessary to inhibit the germination and the growth of C. difficile in vitro. The patient has remained infection free for over 10 months after the initiation of UDCA. UDCA can be considered as a therapeutic option in patients with C. difficile-associated pouchitis. Further studies need to be conducted to define the optimal dose and duration of such a treatment. In addition, bile acid derivatives inhibitory to C. difficile that are able to achieve high intracolonic concentrations may be developed as therapeutics for RCDI colitis.

Examining the Predictive Relations between Two Aspects of Self-Regulation and Growth in Preschool Children’s Early Literacy Skills

PubMed Central

Lonigan, Christopher J.; Allan, Darcey M.; Phillips, Beth M.

2016-01-01

There is strong evidence that self-regulatory processes are linked to early academic skills both concurrently and longitudinally. The majority of extant longitudinal studies, however, have been conducted using autoregressive techniques that may not accurately model change across time. The purpose of this study was to examine the unique associations between two components of self-regulation, attention and executive functioning (EF), and growth in early literacy skills over the preschool year using latent-growth-curve analysis. The sample included 1,082 preschool children (M-age = 55.0 months, SD = 3.73). Children completed measures of vocabulary, syntax, phonological awareness, print knowledge, cognitive ability, and self-regulation, and children’s classroom teachers completed a behavior rating measure. To examine the independent relations of the self-regulatory skills and cognitive ability with children’s initial early literacy skills and growth across the preschool year, growth models in which the intercept and slope were simultaneously regressed on each of the predictor variables were examined. Because of the significant relation between intercept and slope for most outcomes, slope was regressed on intercept in the models to allow a determination of direct and indirect effects of the predictors on growth in children’s language and literacy skills across the preschool year. In general, both teacher-rated inattention and directly measured EF were uniquely associated with initial skills level; however, only teacher-rated inattention uniquely predicted growth in early literacy skills. These findings suggest that teacher-ratings of inattention may measure an aspect of self-regulation that is particularly associated with the acquisition of academic skills in early childhood. PMID:27854463

Riparian vegetation controls on channels formed in non-cohesive sediment

NASA Astrophysics Data System (ADS)

Gran, K.; Tal, M.; Paola, C.

2002-05-01

Riparian vegetation can significantly influence the morphology of a river, affecting channel geometry and flow dynamics. In channels formed in non-cohesive material, vegetation is the main source of bank cohesion and could affect the overall behavior of the river, potentially constraining the flow from a multi-thread channel to a single-thread channel. To examine the effects of riparian vegetation on streams formed in non-cohesive material, we conducted a series of physical experiments at the St. Anthony Falls Laboratory. The first set of experiments examines the effects of varying densities of vegetation on braided stream dynamics. Water discharge, sediment discharge, and grain size were held constant. For each run, we allowed a braided system to develop, then halved the discharge, and seeded the flume with alfalfa (Medicago sativa). After ten to fourteen days of growth, we returned the discharge to its original value and continued the run for 30-36 hours. Our results show that the influence of vegetation on the overall river pattern varied systematically with the spatial density of plant stems. The vegetation reduced the number of active channels and increased bank stability, leading to lower lateral migration rates, narrower and deeper channels, and an increase in channel relief. All these effects increased with vegetation density. Vegetation also influenced flow dynamics, increasing the variance of flow direction in the vegetated runs, and increasing scour depths through strong downwelling where the flow collided with relatively resistant banks. This oblique bank collision provides a new mechanism for producing secondary flows. We found these bank collision driven secondary flows to be more important than the classical curvature-driven mechanism in the vegetated runs. The next set of experiments examines more closely how the channel pattern evolves through time, allowing for both channel migration and successive vegetation growth. In these on-going experiments

Impacts of Parasites in Early Life: Contrasting Effects on Juvenile Growth for Different Family Members

PubMed Central

Reed, Thomas E.; Daunt, Francis; Kiploks, Adam J.; Burthe, Sarah J.; Granroth-Wilding, Hanna M. V.; Takahashi, Emi A.; Newell, Mark; Wanless, Sarah; Cunningham, Emma J. A.

2012-01-01

Parasitism experienced early in ontogeny can have a major impact on host growth, development and future fitness, but whether siblings are affected equally by parasitism is poorly understood. In birds, hatching asynchrony induced by hormonal or behavioural mechanisms largely under parental control might predispose young to respond to infection in different ways. Here we show that parasites can have different consequences for offspring depending on their position in the family hierarchy. We experimentally treated European Shag (Phalacrocorax aristoteli) nestlings with the broad-spectrum anti-parasite drug ivermectin and compared their growth rates with nestlings from control broods. Average growth rates measured over the period of linear growth (10 days to 30 days of age) and survival did not differ for nestlings from treated and control broods. However, when considering individuals within broods, parasite treatment reversed the patterns of growth for individual family members: last-hatched nestlings grew significantly slower than their siblings in control nests but grew faster in treated nests. This was at the expense of their earlier-hatched brood-mates, who showed an overall growth rate reduction relative to last-hatched nestlings in treated nests. These results highlight the importance of exploring individual variation in the costs of infection and suggest that parasites could be a key factor modulating within-family dynamics, sibling competition and developmental trajectories from an early age. PMID:22384190

Growth from birth to early adolescence in offspring prenatally exposed to cigarettes and marijuana.

PubMed

Fried, P A; Watkinson, B; Gray, R

1999-01-01

Weight, height, and head circumference were examined in children from birth to early adolescence for whom prenatal exposure to marijuana and cigarettes had been ascertained. The subjects were from a low-risk, predominantly middle-class sample participating in an ongoing longitudinal study. The negative association between growth measures at birth and prenatal cigarette exposure was overcome, sooner in males than females, within the first few years, and by the age of six, the children of heavy smokers were heavier than control subjects. Pre and postnatal environmental tobacco smoke did not have a negative effect upon the growth parameters; however, the choice of bottle-feeding or shorter duration of breast-feeding by women who smoked during pregnancy appeared to play an important positive role in the catch-up observed among the infants of smokers. Prenatal exposure to marijuana was not significantly related to any growth measures at birth, although a smaller head circumference observed at all ages reached statistical significance among the early adolescents born to the heavy marijuana users.

Woody vegetation, fuel and fire track the melting of the Scandinavian ice-sheet before 9500 cal yr BP

NASA Astrophysics Data System (ADS)

Carcaillet, Christopher; Hörnberg, Greger; Zackrisson, Olle

2012-11-01

New studies indicate the presence of early Holocene ice-free areas far north in Scandinavia. Post-glacial fire and vegetation were investigated based on sedimentary charcoal and pollen from two small lakes in northern Sweden. Accumulation of organic sediment started around 10,900 and 9200 cal yr BP, showing that both lake valleys were ice-free extremely early given their northerly location. Fire events started after 9600 cal yr BP and became less common around the '8.2-ka event'. Woody vegetation provided fuel that contributed to fires. The first vegetation in our pollen record consisted of Hippophae, Dryas, grasses and sedges. Subsequently broadleaved trees (Betula, Salix) increased in abundance and later Pinus, Alnus, ferns and Lycopodium characterized the vegetation. Pollen from Larix, Picea and Malus were also found. The change in vegetation composition was synchronous with the decrease in lake-water pH in the region, indicating ecosystem-scale processes; this occurred during a period of net global and regional warming. The changes in fire frequency and vegetation appear independent of regional trends in precipitation. The reconstructed fire history and vegetation support the scenario of early ice-free areas far north in Scandinavia during early Holocene warming, creating favorable conditions for woody plants and wildfires.

Oxygen-sensitive regulation and neuroprotective effects of growth hormone-dependent growth factors during early postnatal development.

PubMed

Jung, Susan; Boie, Gudrun; Doerr, Helmuth-Guenther; Trollmann, Regina

2017-04-01

Perinatal hypoxia severely disrupts metabolic and somatotrophic development, as well as cerebral maturational programs. Hypoxia-inducible transcription factors (HIFs) represent the most important endogenous adaptive mechanisms to hypoxia, activating a broad spectrum of growth factors that contribute to cell survival and energy homeostasis. To analyze effects of systemic hypoxia and growth hormone (GH) therapy (rhGH) on HIF-dependent growth factors during early postnatal development, we compared protein (using ELISA) and mRNA (using quantitative RT PCR) levels of growth factors in plasma and brain between normoxic and hypoxic mice (8% O 2 , 6 h; postnatal day 7 , P7) at P14. Exposure to hypoxia led to reduced body weight ( P < 0.001) and length ( P < 0.04) compared with controls and was associated with significantly reduced plasma levels of mouse GH ( P < 0.01) and IGF-1 ( P < 0.01). RhGH abrogated these hypoxia-induced changes of the GH/IGF-1 axis associated with normalization of weight and length gain until P14 compared with controls. In addition, rhGH treatment increased cerebral IGF-1, IGF-2, IGFBP-2, and erythropoietin mRNA levels, resulting in significantly reduced apoptotic cell death in the hypoxic, developing mouse brain. These data indicate that rhGH may functionally restore hypoxia-induced systemic dysregulation of the GH/IGF-1 axis and induce upregulation of neuroprotective, HIF-dependent growth factors in the hypoxic developing brain. Copyright © 2017 the American Physiological Society.

EGFR ligands drive multipotential stromal cells to produce multiple growth factors and cytokines via early growth response-1.

PubMed

Kerpedjieva, Svetoslava S; Kim, Duk Soo; Barbeau, Dominique J; Tamama, Kenichi

2012-09-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)-EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase-extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands.

Placental pathology in early intrauterine growth restriction associated with maternal hypertension.

PubMed

Veerbeek, J H W; Nikkels, P G J; Torrance, H L; Gravesteijn, J; Post Uiterweer, E D; Derks, J B; Koenen, S V; Visser, G H A; Van Rijn, B B; Franx, A

2014-09-01

To identify key pathological characteristics of placentas from pregnancies complicated by early intrauterine growth restriction, and to examine their relations with maternal hypertensive disease and umbilical artery Doppler waveform abnormalities. Single-center retrospective cohort study of singleton pregnancies with abnormal umbilical artery Doppler flow patterns resulting in a live birth <34 weeks of a baby with a weight <10th percentile for gestational age. Umbilical artery end diastolic flow was classified as being either present or absent/reversed (AREDF). Data were stratified into intrauterine growth restriction with or without hypertensive disease and pathological characteristics were compared between these various conditions according to predefined scoring criteria. Among 164 placentas studied, we found high rates of characteristic histopathological features that were associated with intrauterine growth restriction, including infarction (>5% in 42%), chronic villitis (21%), chronic chorioamnionitis (36%), membrane necrosis (20%), elevated nucleated red blood cells (89%), increased syncytial knotting (93%), increased villous maturation (98%), fetal thrombosis (32%) and distal villous hypoplasia (35%). Chronic inflammation of fetal membranes and syncytial knotting were more common in women with concomitant hypertensive disease as compared to women with normotensive IUGR (p < 0.05). Placentas from women with umbilical artery AREDF were more likely to show increased numbers of nucleated red blood cells and distal villous hypoplasia (p < 0.05). Placentas of women with early IUGR show high rates of several histological aberrations. Further, concomitant maternal hypertension is associated with characteristic inflammatory changes and umbilical artery AREDF with signs of chronic hypoxia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of thermally-oxidized vegetable oils and animal fats on growth performance, liver gene expression, and liver and serum cholesterol and triglycerides in young pigs

USDA-ARS?s Scientific Manuscript database

To evaluate the effect of feeding thermally-oxidized vegetable oils and animal fats on growth performance, liver gene expression, and liver and serum fatty acid and cholesterol concentration in young pigs, 102 barrows (6.67 ± 0.03 kg BW) were divided into 3 groups and randomly assigned to dietary tr...

Salad Machine - A vegetable production unit for long duration space missions

NASA Technical Reports Server (NTRS)

Kliss, M.; Macelroy, R. D.

1990-01-01

A review of NASA CELSS development specific to vegetable cultivation during space missions is presented in terms of enhancing the quality of life for space crews. A cultivation unit is being developed to permit the production of 600 grams of edible salad vegetables per week, thereby allowing one salad per crew member three times weekly. Plant-growth requirements are set forth for the specific vegetables, and environmental subsystems are listed. Several preprototype systems are discussed, and one particular integrated-systems design concept is presented in detail with views of the proposed rack configuration. The Salad Machine is developed exclusively from CELSS-derived technology, and the major challenge is the mitigation of the effects of plant-growth requirements on other space-mission facility operations.

A rootstock provides water conservation for a grafted commercial tomato (Solanum lycopersicum L.) line in response to mild-drought conditions: a focus on vegetative growth and photosynthetic parameters.

PubMed

Nilsen, Erik T; Freeman, Joshua; Grene, Ruth; Tokuhisa, James

2014-01-01

The development of water stress resistant lines of commercial tomato by breeding or genetic engineering is possible, but will take considerable time before commercial varieties are available for production. However, grafting commercial tomato lines on drought resistant rootstock may produce drought tolerant commercial tomato lines much more rapidly. Due to changing climates and the need for commercial production of vegetables in low quality fields there is an urgent need for stress tolerant commercial lines of vegetables such as tomato. In previous observations we identified a scion root stock combination ('BHN 602' scion grafted onto 'Jjak Kkung' rootstock hereafter identified as 602/Jjak) that had a qualitative drought-tolerance phenotype when compared to the non-grafted line. Based on this initial observation, we studied photosynthesis and vegetative above-ground growth during mild-drought for the 602/Jjak compared with another scion-rootstock combination ('BHN 602' scion grafted onto 'Cheong Gang' rootstock hereafter identified as 602/Cheong) and a non-grafted control. Overall above ground vegetative growth was significantly lower for 602/Jjak in comparison to the other plant lines. Moreover, water potential reduction in response to mild drought was significantly less for 602/Jjak, yet stomatal conductance of all plant-lines were equally inhibited by mild-drought. Light saturated photosynthesis of 602/Jjak was less affected by low water potential than the other two lines as was the % reduction in mesophyll conductance. Therefore, the Jjak Kkung rootstock caused aboveground growth reduction, water conservation and increased photosynthetic tolerance of mild drought. These data show that different rootstocks can change the photosynthetic responses to drought of a high yielding, commercial tomato line. Also, this rapid discovery of one scion-rootstock combination that provided mild-drought tolerance suggests that screening more scion-rootstock combination for

Early brush control promotes growth of ponderosa pine planted on bulldozed site

Treesearch

Jay R. Bentley; Stanley B. Carpenter; David A. Blakeman

1971-01-01

Test plots in a brushfield near Mount Shasta, California, were cleared by bulldozing in 1961, and planted with ponderosa pine seedlings in 1962. Brush regrowth was subjected to varying levels of control by spraying with herbicides. In the first 5 years, brush control definitely promoted the growth of pine seedlings. And this early control also promises to reduce the...

Germination and early growth of coastal tree species on organic seed beds.

Treesearch

Don Minore

1972-01-01

Germination and early growth on rotten wood and duff under several shade levels were observed for Douglas-fir, Sitka spruce, western hemlock, western redcedar, lodgepole pine, Pacific silver fir, and red alder. Nutrients were more abundant in duff than in rotten wood. Seedlings usually were larger and more abundant on duff-covered rotten logs than on duff-covered...

Smart phone video game simulation of parent-child interaction: Learning skills for effective vegetable parenting

USDA-ARS?s Scientific Manuscript database

Higher levels of vegetable intake have been associated with decreased risks of heart disease, diabetes, stroke, several cancers, and possibly obesity, but vegetable intake is generally low. Preference is an important determinant of vegetable intake, and food preferences are initiated early in life, ...

Patatin-related phospholipase A, pPLAIIIα, modulates the longitudinal growth of vegetative tissues and seeds in rice

PubMed Central

Liu, Guangmeng; Zhang, Ke; Ai, Jun; Deng, Xianjun; Hong, Yueyun; wang, Xuemin

2015-01-01

Patatin-related phospholipase A (pPLA) hydrolyses glycerolipids to produce fatty acids and lysoglycerolipids. The Oryza sativa genome has 21 putative pPLAs that are grouped into five subfamilies. Overexpression of OspPLAIIIα resulted in a dwarf phenotype with decreased length of rice stems, roots, leaves, seeds, panicles, and seeds, whereas OspPLAIIIα-knockout plants had longer panicles and seeds. OspPLAIIIα-overexpressing plants were less sensitive than wild-type and knockout plants to gibberellin-promoted seedling elongation. OspPLAIIIα overexpression and knockout had an opposite effect on the expression of the growth repressor SLENDER1 in the gibberellin signalling process. OspPLAIIIα-overexpressing plants had decreased mechanical strength and cellulose content, but exhibited increases in the expression of several cellulose synthase genes. These results indicate that OspPLAIIIα plays a role in rice vegetative and reproductive growth and that the constitutive, high activity of OspPLAIIIα suppresses cell elongation. The decreased gibberellin response in overexpressing plants is probably a result of the decreased ability to make cellulose for anisotropic cell expansion. PMID:26290597

Using FIA data in the Forest Vegetation Simulator

Treesearch

John D. Shaw

2009-01-01

The Forest Vegetation Simulator (FVS) is a national system of forest growth models maintained by the USDA Forest Service. It is the official tool for stand growth projection on National Forest lands, but it is also used widely on other ownerships. Model extensions and post-processors permit FVS users to perform a broad range of functions, including silvicultural...

Identification of pathways directly regulated by SHORT VEGETATIVE PHASE during vegetative and reproductive development in Arabidopsis

PubMed Central

2013-01-01

Background MADS-domain transcription factors play important roles during plant development. The Arabidopsis MADS-box gene SHORT VEGETATIVE PHASE (SVP) is a key regulator of two developmental phases. It functions as a repressor of the floral transition during the vegetative phase and later it contributes to the specification of floral meristems. How these distinct activities are conferred by a single transcription factor is unclear, but interactions with other MADS domain proteins which specify binding to different genomic regions is likely one mechanism. Results To compare the genome-wide DNA binding profile of SVP during vegetative and reproductive development we performed ChIP-seq analyses. These ChIP-seq data were combined with tiling array expression analysis, induction experiments and qRT-PCR to identify biologically relevant binding sites. In addition, we compared genome-wide target genes of SVP with those published for the MADS domain transcription factors FLC and AP1, which interact with SVP during the vegetative and reproductive phases, respectively. Conclusions Our analyses resulted in the identification of pathways that are regulated by SVP including those controlling meristem development during vegetative growth and flower development whereas floral transition pathways and hormonal signaling were regulated predominantly during the vegetative phase. Thus, SVP regulates many developmental pathways, some of which are common to both of its developmental roles whereas others are specific to only one of them. PMID:23759218

Plant Growth Research for Food Production: Development and Testing of Expandable Tuber Growth Module

NASA Technical Reports Server (NTRS)

Cordova, Brennan A.

2017-01-01

Controlled and reliable growth of a variety of vegetable crops is an important capability for manned deep space exploration systems for providing nutritional supplementation and psychological benefits to crew members. Because current systems have been limited to leafy vegetables that require minimal root space, a major goal for these systems is to increase their ability to grow new types of crops, including tuber plants and root vegetables that require a large root space. An expandable root zone module and housing was developed to integrate this capability into the Veggie growth system. The expandable module uses a waterproof, gas-permeable bag with a structure that allows for root space to increase vertically throughout the growth cycle to accommodate for expanding tuber growth, while minimizing the required media mass. Daikon radishes were chosen as an ideal tuber crop for their subterraneous tuber size and rapid growth cycle, and investigations were done to study expanding superabsorbent hydrogels as a potential growth media. These studies showed improved water retention, but restricted oxygen availability to roots with pure gel media. It was determined that these hydrogels could be integrated in lower proportions into standard soil to achieve media expansion and water retention desired. Using the constructed module prototype and ideal gel and soil media mixture, Daikon radishes were grown in the system to test the capability and success of the system through a full growth cycle.

Diverse Responses of Global Vegetation to Climate Changes: Spatial Patterns and Time-lag Effects

NASA Astrophysics Data System (ADS)

Wu, D.; Zhao, X.; Zhou, T.; Huang, K.; Xu, W.

2014-12-01

Global climate changes have enormous influences on vegetation growth, meanwhile, response of vegetation to climate express space diversity and time-lag effects, which account for spatial-temporal disparities of climate change and spatial heterogeneity of ecosystem. Revelation of this phenomenon will help us further understanding the impact of climate change on vegetation. Assessment and forecast of global environmental change can be also improved under further climate change. Here we present space diversity and time-lag effects patterns of global vegetation respond to three climate factors (temperature, precipitation and solar radiation) based on quantitative analysis of satellite data (NDVI) and Climate data (Climate Research Unit). We assessed the time-lag effects of global vegetation to main climate factors based on the great correlation fitness between NDVI and the three climate factors respectively among 0-12 months' temporal lags. On this basis, integrated response model of NDVI and the three climate factors was built to analyze contribution of different climate factors to vegetation growth with multiple regression model and partial correlation model. In the result, different vegetation types have distinct temporal lags to the three climate factors. For the precipitation, temporal lags of grasslands are the shortest while the evergreen broad-leaf forests are the longest, which means that grasslands are more sensitive to precipitation than evergreen broad-leaf forests. Analysis of different climate factors' contribution to vegetation reveal that vegetation are dominated by temperature in the high northern latitudes; they are mainly restricted by precipitation in arid and semi-arid areas (Australia, Western America); in humid areas of low and intermediate latitudes (Amazon, Eastern America), vegetation are mainly influenced by solar radiation. Our results reveal the time-lag effects and major driving factors of global vegetation growth and explain the

Lazy gene (la) responsible for both an agravitropism of seedlings and lazy habit of tiller growth in rice (Oryza sativa L.).

PubMed

Abe, K; Takahashi, H; Suge, H

1996-12-01

Using an isogenic line of rice having lazy gene (la), we studied the correlation between the agravitropic response at the young seedling stage and the lazy habit (prostrate growth of tillers) at the more advanced stage of growth. In this study, it was found that both agravitropism and lazy habit were controlled by the single recessive la gene. That is, F2 segregants of Kamenoo x lazy-Kamenoo, which had an agravitropic response at their young seedling stage, showed a lazy habit of growth in the more advanced stage of vegetative growth. On the other hand, seedlings that showed normal gravitropic curvature at their early stage of growth had an upright growth in the mature stage.

Relations between red alder composition and understory vegetation in young mixed forests of southeast Alaska.

Treesearch

Thomas A. Hanley; Robert L. Deal; Ewa H. Orlikowska

2006-01-01

Interest in mixed red alder (Alnus rubra Bong.)—conifer young-growth stands has grown in southeast Alaska, USA, because they appear to provide much more productive understory vegetation and wildlife habitat than do similar-aged pure conifer stands. We studied understory vegetation in nine even-aged young-growth stands (38-42 years old)...

Early Life Factors and Inter-Country Heterogeneity in BMI Growth Trajectories of European Children: The IDEFICS Study

PubMed Central

Börnhorst, Claudia; Siani, Alfonso; Russo, Paola; Kourides, Yannis; Sion, Isabelle; Molnár, Denés; Moreno, Luis A.; Rodríguez, Gerardo; Ben-Shlomo, Yoav; Howe, Laura; Lissner, Lauren; Mehlig, Kirsten; Regber, Susann; Bammann, Karin; Foraita, Ronja

2016-01-01

Background Starting from birth, this explorative study aimed to investigate between-country differences in body mass index (BMI) trajectories and whether early life factors explain these differences. Methods The sample included 7,644 children from seven European countries (Belgium, Cyprus, Germany, Hungary, Italy, Spain, Sweden) participating in the multi-centre IDEFICS study. Information on early life factors and in total 53,409 repeated measurements of height and weight from 0 to <12 years of age were collected during the baseline (2007/2008) and follow-up examination (2009/2010) supplemented by records of routine child health visits. Country-specific BMI growth curves were estimated using fractional polynomial mixed effects models. Several covariates focussing on early life factors were added to the models to investigate their role in the between-countries differences. Results Large between-country differences were observed with Italian children showing significantly higher mean BMI values at all ages ≥ 3 years compared to the other countries. For instance, at age 11 years mean BMI values in Italian boys and girls were 22.3 [21.9;22.8; 99% confidence interval] and 22.0 [21.5;22.4], respectively, compared to a range of 18.4 [18.1;18.8] to 20.3 [19.8;20.7] in boys and 18.2 [17.8;18.6] to 20.3 [19.8;20.7] in girls in the other countries. After adjustment for early life factors, differences between country-specific BMI curves became smaller. Maternal BMI was the factor being most strongly associated with BMI growth (p<0.01 in all countries) with associations increasing during childhood. Gestational weight gain (GWG) was weakly associated with BMI at birth in all countries. In some countries, positive associations between BMI growth and children not being breastfed, mothers’ smoking during pregnancy and low educational level of parents were found. Conclusion Early life factors seem to explain only some of the inter-country variation in growth. Maternal BMI showed

Early Life Growth Predicts Pubertal Development in South African Adolescents.

PubMed

Lundeen, Elizabeth A; Norris, Shane A; Martorell, Reynaldo; Suchdev, Parminder S; Mehta, Neil K; Richter, Linda M; Stein, Aryeh D

2016-03-01

Given global trends toward earlier onset of puberty and the adverse psychosocial consequences of early puberty, it is important to understand the childhood predictors of pubertal timing and tempo. We examined the association between early growth and the timing and tempo of puberty in adolescents in South Africa. We analyzed prospectively collected data from 1060 boys and 1135 girls participating in the Birth-to-Twenty cohort in Soweto, South Africa. Height-for-age z scores (HAZs) and body mass index-for-age z scores (BMIZs) were calculated based on height (centimeters) and body mass index (kilograms per meter squared) at ages 5 y and 8 y. The development of genitals, breasts, and pubic hair was recorded annually from 9 to 16 y of age with the use of the Tanner sexual maturation scale (SMS). We used latent class growth analysis to identify pubertal trajectory classes and also characterized children as fast or slow developers based on the SMS score at 12 y of age. We used multinomial logistic regression to estimate associations of HAZ and BMIZ at ages 5 and 8 y with pubertal development. We identified 3 classes for pubic hair development (for both girls and boys) and 4 classes for breast (for girls) and genital (for boys) development. In girls, both HAZ and BMIZ at age 5 y were positively associated with pubic hair development [relative risk ratio (RRR): 1.57, P < 0.001 and RRR: 1.51, P < 0.01, respectively], as was BMI at age 8 y (RRR: 2.06, P = 0.03); similar findings were observed for breast development. In boys, HAZ and BMIZ at age 5 y were positively associated with pubic hair development (RRR: 1.78, P < 0.001 and RRR: 1.43, P < 0.01, respectively); HAZ at age 5 y was associated with development of genitals (RRR: 2.19, P < 0.01). In boys and girls, both height and body mass index in early childhood predicted the trajectory of pubertal development. This may provide a tool to identify children at risk of early pubertal onset.

Psychometric assessment of scales for a Model of Goal Directed Vegetable Parenting Practices (MGDVPP)

USDA-ARS?s Scientific Manuscript database

Vegetable intake has been related to lower risk of chronic illnesses in the adult years. The habit of vegetable intake should be established early in life, but many parents of preschoolers report not being able to get their child to eat vegetables. The Model of Goal Directed Behavior (MGDB) has been...

Oscillations in a simple climate-vegetation model

NASA Astrophysics Data System (ADS)

Rombouts, J.; Ghil, M.

2015-05-01

We formulate and analyze a simple dynamical systems model for climate-vegetation interaction. The planet we consider consists of a large ocean and a land surface on which vegetation can grow. The temperature affects vegetation growth on land and the amount of sea ice on the ocean. Conversely, vegetation and sea ice change the albedo of the planet, which in turn changes its energy balance and hence the temperature evolution. Our highly idealized, conceptual model is governed by two nonlinear, coupled ordinary differential equations, one for global temperature, the other for vegetation cover. The model exhibits either bistability between a vegetated and a desert state or oscillatory behavior. The oscillations arise through a Hopf bifurcation off the vegetated state, when the death rate of vegetation is low enough. These oscillations are anharmonic and exhibit a sawtooth shape that is characteristic of relaxation oscillations, as well as suggestive of the sharp deglaciations of the Quaternary. Our model's behavior can be compared, on the one hand, with the bistability of even simpler, Daisyworld-style climate-vegetation models. On the other hand, it can be integrated into the hierarchy of models trying to simulate and explain oscillatory behavior in the climate system. Rigorous mathematical results are obtained that link the nature of the feedbacks with the nature and the stability of the solutions. The relevance of model results to climate variability on various timescales is discussed.

Oscillations in a simple climate-vegetation model

NASA Astrophysics Data System (ADS)

Rombouts, J.; Ghil, M.

2015-02-01

We formulate and analyze a simple dynamical systems model for climate-vegetation interaction. The planet we consider consists of a large ocean and a land surface on which vegetation can grow. The temperature affects vegetation growth on land and the amount of sea ice on the ocean. Conversely, vegetation and sea ice change the albedo of the planet, which in turn changes its energy balance and hence the temperature evolution. Our highly idealized, conceptual model is governed by two nonlinear, coupled ordinary differential equations, one for global temperature, the other for vegetation cover. The model exhibits either bistability between a vegetated and a desert state or oscillatory behavior. The oscillations arise through a Hopf bifurcation off the vegetated state, when the death rate of vegetation is low enough. These oscillations are anharmonic and exhibit a sawtooth shape that is characteristic of relaxation oscillations, as well as suggestive of the sharp deglaciations of the Quaternary. Our model's behavior can be compared, on the one hand, with the bistability of even simpler, Daisyworld-style climate-vegetation models. On the other hand, it can be integrated into the hierarchy of models trying to simulate and explain oscillatory behavior in the climate system. Rigorous mathematical results are obtained that link the nature of the feedbacks with the nature and the stability of the solutions. The relevance of model results to climate variability on various time scales is discussed.

Physiological and morphological changes during early and later stages of fruit growth in Capsicum annuum.

PubMed

Tiwari, Aparna; Vivian-Smith, Adam; Ljung, Karin; Offringa, Remko; Heuvelink, Ep

2013-03-01

Fruit-set involves a series of physiological and morphological changes that are well described for tomato and Arabidopsis, but largely unknown for sweet pepper (Capsicum annuum). The aim of this paper is to investigate whether mechanisms of fruit-set observed in Arabidopsis and tomato are also applicable to C. annuum. To do this, we accurately timed the physiological and morphological changes in a post-pollinated and un-pollinated ovary. A vascular connection between ovule and replum was observed in fertilized ovaries that undergo fruit development, and this connection was absent in unfertilized ovaries that abort. This indicates that vascular connection between ovule and replum is an early indicator for successful fruit development after pollination and fertilization. Evaluation of histological changes in the carpel of a fertilized and unfertilized ovary indicated that increase in cell number and cell diameter both contribute to early fruit growth. Cell division contributes more during early fruit growth while cell expansion contributes more at later stages of fruit growth in C. annuum. The simultaneous occurrence of a peak in auxin concentration and a strong increase in cell diameter in the carpel of seeded fruits suggest that indole-3-acetic acid stimulates a major increase in cell diameter at later stages of fruit growth. The series of physiological and morphological events observed during fruit-set in C. annuum are similar to what has been reported for tomato and Arabidopsis. This indicates that tomato and Arabidopsis are suitable model plants to understand details of fruit-set mechanisms in C. annuum. Copyright © Physiologia Plantarum 2012.

Cell phone radiations affect early growth of Vigna radiata (mung bean) through biochemical alterations.

PubMed

Sharma, Ved Parkash; Singh, Harminder Pal; Batish, Daizy Rani; Kohli, Ravinder Kumar

2010-01-01

The indiscriminate use of wireless technologies, particularly of cell phones, has increased the health risks among living organisms including plants. We investigated the impact of cell phone electromagentic field (EMF) radiations (power density, 8.55 microW cm(-2)) on germination, early growth, proteins and carbohydrate contents, and activities of some enzymes in Vigna radiata. Cell phone EMF radiations significantly reduced the seedling length and dry weight of V radiata after exposure for 0.5, 1, 2, and 4 h. Furthermore, the contents of proteins and carbohydrates were reduced in EMF-exposed plants. However, the activities of proteases, alpha-amylases, beta-amylases, polyphenol oxidases, and peroxidases were enhanced in EMF-exposed radicles indicating their role in providing protection against EMF-induced stress. The study concludes that cell phone EMFs impair early growth of V radiata seedlings by inducing biochemical changes.

The Groove of Growth: How Early Gains in Math Ability Influence Adolescent Achievement

ERIC Educational Resources Information Center

Watts, Tyler W.; Duncan, Greg J.; Siegler, Robert S.; Davis-Kean, Pamela E.

2014-01-01

A number of studies, both small scale and of nationally-representative student samples, have reported substantial associations between school entry math ability and later elementary school achievement. However, questions remain regarding the persistence of the association between early growth in math ability and later math achievement due to the…

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

Treesearch

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...

MODIS normalized difference vegetation index (NDVI) and vegetation phenology dynamics in the Inner Mongolia grassland

NASA Astrophysics Data System (ADS)

Gong, Z.; Kawamura, K.; Ishikawa, N.; Goto, M.; Wulan, T.; Alateng, D.; Yin, T.; Ito, Y.

2015-11-01

The Inner Mongolia grassland, one of the most important grazing regions in China, has long been threatened by land degradation and desertification, mainly due to overgrazing. To understand vegetation responses over the last decade, this study evaluated trends in vegetation cover and phenology dynamics in the Inner Mongolia grassland by applying a normalized difference vegetation index (NDVI) time series obtained by the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) during 2002-2014. The results showed that the cumulative annual NDVI increased to over 77.10 % in the permanent grassland region (2002-2014). The mean value of the total change showed that the start of season (SOS) date and the peak vegetation productivity date of the season (POS) had advanced by 5.79 and 2.43 days, respectively. The end of season (EOS) was delayed by 5.07 days. These changes lengthened the season by 10.86 days. Our results also confirmed that grassland changes are closely related to spring precipitation and increasing temperature at the early growing period because of global warming. Overall, productivity in the Inner Mongolia Autonomous Region tends to increase, but in some grassland areas with grazing, land degradation is ongoing.

Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

USGS Publications Warehouse

Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

2016-01-01

Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

Role of MODIS Vegetation Phenology Products in the U.S. for Warn Early Warning System for Forest Threats

NASA Technical Reports Server (NTRS)

Spruce, Joseph; Hargrove, William; Norman, Steve; Gasser, Gerald; Smoot, James; Kuper, Philip

2012-01-01

U.S. forests occupy approx 751 million acres (approx 1/3 of total land). Several abiotic and biotic damage agents disturb, damage, kill, and/or threaten these forests. Regionally extensive forest disturbances can also threaten human life and property, bio-diversity and water supplies. timely regional forest disturbance monitoring products are needed to aid forest health management work at finer scales. daily MODIS data provide a means to monitor regional forest disturbances on a weekly basis, leveraging vegetation phenology. In response, the USFS and NASA began collaborating in 2006 to develop a Near Real Time (NRT) forest monitoring capability, based on MODIS NDVI data, as part of a national forest threat Early Warning System (EWS).

Proteomic Analysis of Bacillus thuringiensis Strain 4.0718 at Different Growth Phases

PubMed Central

Li, Xiaohui; Ding, Xuezhi; Xia, Liqiu; Sun, Yunjun; Yuan, Can; Yin, Jia

2012-01-01

The growth process of Bacillus thuringiensis Bt4.0718 strain was studied using proteomic technologies. The proteins of Bt whole cells at three phases—middle vegetative, early sporulation, and late sporulation—were extracted with lysis buffer, followed with separation by 2-DE and identified by MALDI-TOF/TOF MS. Bioactive factors such as insecticidal crystal proteins (ICPs) including Cry1Ac(3), Cry2Aa, and BTRX28, immune inhibitor (InhA), and InhA precursor were identified. InhA started to express at the middle vegetative phase, suggesting its contribution to the survival of Bt in the host body. At the early sporulation phase, ICPs started their expression. CotJC, OppA, ORF1, and SpoIVA related to the formation of crystals and spores were identified, the expression characteristics of which ensured the stable formation of crystals and spores. This study provides an important foundation for further exploration of the stable expression of ICPs, the smooth formation of crystals, and the construction of recombinant strains. PMID:22649324

Effect of mineral sulphur availability on nitrogen and sulphur uptake and remobilization during the vegetative growth of Brassica napus L.

PubMed Central

Abdallah, M.; Dubousset, L.; Meuriot, F.; Etienne, P.; Avice, J-C.; Ourry, A.

2010-01-01

Because it has a high demand for sulphur (S), oilseed rape is particularly sensitive to S limitation. However, the physiological effects of S limitation remain unclear, especially during the rosette stage. For this reason a study was conducted to determine the effects of mineral S limitation on nitrogen (N) and S uptake and remobilization during vegetative growth of oilseed rape at both the whole-plant and leaf rank level for plants grown during 35 d with 300 μM 34SO42– (control plants; +S) or with 15 μM 34SO42– (S-limited plants; –S). The results highlight that S-limited plants showed no significant differences either in whole-plant and leaf biomas or in N uptake, when compared with control plants. However, total S and 34S (i.e. deriving from S uptake) contents were greatly reduced for the whole plant and leaf after 35 d, and a greater redistribution of endogenous S from leaves to the benefit of roots was observed. The relative expression of tonoplast and plasmalemma sulphate transporters was also strongly induced in the roots. In conclusion, although S-limited plants had 20 times less mineral S than control plants, their development remained surprisingly unchanged. During S limitation, oilseed rape is able to recycle endogenous S compounds (mostly sulphate) from leaves to roots. However, this physiological adaptation may be effective only over a short time scale (i.e. vegetative growth). PMID:20403880

On the role of vegetation in the formation of river anabranching patterns

NASA Astrophysics Data System (ADS)

Crouzy, B.; D'Odorico, P.; Wütrich, D.; Perona, P.

2012-04-01

Part of studies on the couplings between the evolution of riparian vegetation and the river morphodynamics, we investigate the effect of spatial interactions between vegetation located at different positions within the channel. This work generalizes the experimental and theoretical results by Perona et al. and by Crouzy and Perona (both Advances in Water Resources, in Press) on colonization of riverbars by seedlings or large woody debris by relaxing the hypothesis made in those two works of the biomass growth and uprooting being independent on the presence of neighboring plants. While the hypothesis of independent vegetation growth and uprooting is justified for sparse vegetation cover or young seedlings, it fails as soon as the canopy significantly disturbs the flow or changes the sediment stability. Then, flow-mediated interactions between riparian vegetation located at different positions within the channel can be observed. Those interactions are either constructive or destructive. For example, a region favorable to the development of biomass appears on the lee side of a vegetated obstacle (with bleed flow) due to increased deposition of seeds and sediment (Schnauder and Moggridge, 2008) while conversely scouring can be increased laterally due to obstacle-induced flow diversion (Roulund et al., 2005; Melville and Sutherland, 1988; Zong and Nepf, 2008). We focus on the role of vegetation in the formation of the regular vegetated ridge patterns found in ephemeral rivers (see for example the work by Tooth and Nanson, 2004 on anabranching patterns) or as a succession of swales and ridges on the inside of meander bends (scroll bars). From the analysis of aerial images, we obtain the characteristic length scale of the patterns. We show how in the limit where the hydrological (interarrival time of floods) and the biological (germination and growth rates) timescales are comparable the combination between both positive and negative feedbacks between vegetation located at

EGFR Ligands Drive Multipotential Stromal Cells to Produce Multiple Growth Factors and Cytokines via Early Growth Response-1

PubMed Central

Kerpedjieva, Svetoslava S.; Kim, Duk Soo; Barbeau, Dominique J.

2012-01-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)–EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase–extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands. PMID:22316125

Study on the vegetation dynamic change using long time series of remote sensing data

NASA Astrophysics Data System (ADS)

Fan, Jinlong; Zhang, Xiaoyu

2010-10-01

The vegetation covering land surface is main component of biosphere which is one of five significant spheres on the earth. The vegetation plays a very important role on the natural environment conservation and improvement to keep human being's living environment evergreen while the vegetation supplies many natural resources to human living and development continuously. Under the background of global warming, vegetation is changing as climate changes. It is not doubt that human activities have great effects on the vegetation dynamic. In general, there are two aspects of the interaction between vegetation and climate, the climatic adaptation of vegetation and the vegetation feedback on climate. On the base of the research on the long term vegetation growth dynamics, it can be found out the vegetation adaptation to climate change. The dynamic change of vegetation is the direct indicator of the ecological environment changes. Therefore, study on the dynamic change of vegetation will be very interest and useful. In this paper, the vegetation change in special region of China will be described in detail. In addition to the methods of the long term in-situ observation of vegetation, remote sensing technologies can also be used to study the long time series vegetation dynamic. The widely used NDVI was often employed to monitor the status of vegetation growth. Actually, NDVI can indicate the vigor and the fractional cover of vegetation effectively. So the long time series of NDVI datasets are a very valuable data source supporting the study on the long term vegetation dynamics. Since 1980, a series of NOAA satellites have been launched successfully, which have already supplied more than 20 years NOAA/AVHRR satellites data. In this paper, we selected Ningxia Hui autonomic region of China as the case study area and used 20 years pathfinder AVHRR NDVI data to carry out the case study on the vegetation dynamics in order to further understand the phenomena of 20 years vegetation

Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

NASA Astrophysics Data System (ADS)

Atherton, Daniel

Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p < 0.0001) between disease rating group means. In the majority of the experiments, comparisons of diseased plants with healthy plants using Fisher's LSD revealed more heavily diseased plants were significantly different from healthy plants. PLS analysis demonstrated the feasibility of detecting early blight infected plants, finding four optimal factors for raw spectra with the predictor variation explained ranging from 93.4% to 94.6% and the response variation explained ranging from 42.7% to 64.7%. Cluster analysis successfully distinguished healthy plants from all diseased plants except for the most mildly diseased plants, showing clustering analysis was an effective method for detection of early blight. Analysis of the reflectance spectra using the simple ratio (SR) and the normalized difference vegetative index (NDVI) was effective at differentiating all diseased plants from healthy plants, except for the

Super-optimal CO2 reduces seed yield but not vegetative growth in wheat

NASA Technical Reports Server (NTRS)

Grotenhuis, T. P.; Bugbee, B.

1997-01-01

Although terrestrial atmospheric CO2 levels will not reach 1000 micromoles mol-1 (0.1%) for decades, CO2 levels in growth chambers and greenhouses routinely exceed that concentration. CO2 levels in life support systems in space can exceed 10000 micromoles mol-1(1%). Numerous studies have examined CO2 effects up to 1000 micromoles mol-1, but biochemical measurements indicate that the beneficial effects of CO2 can continue beyond this concentration. We studied the effects of near-optimal (approximately 1200 micromoles mol-1) and super-optimal CO2 levels (2400 micromoles mol-1) on yield of two cultivars of hydroponically grown wheat (Triticum aestivum L.) in 12 trials in growth chambers. Increasing CO2 from sub-optimal to near-optimal (350-1200 micromoles mol-1) increased vegetative growth by 25% and seed yield by 15% in both cultivars. Yield increases were primarily the result of an increased number of heads per square meter. Further elevation of CO2 to 2500 micromoles mol-1 reduced seed yield by 22% (P < 0.001) in cv. Veery-10 and by 15% (P < 0.001) in cv. USU-Apogee. Super-optimal CO2 did not decrease the number of heads per square meter, but reduced seeds per head by 10% and mass per seed by 11%. The toxic effect of CO2 was similar over a range of light levels from half to full sunlight. Subsequent trials revealed that super-optimal CO2 during the interval between 2 wk before and after anthesis mimicked the effect of constant super-optimal CO2. Furthermore, near-optimal CO2 during the same interval mimicked the effect of constant near-optimal CO2. Nutrient concentration of leaves and heads was not affected by CO2. These results suggest that super-optimal CO2 inhibits some process that occurs near the time of seed set resulting in decreased seed set, seed mass, and yield.

The influence of burn severity on postfire vegetation recovery and albedo change during early succession in North American boreal forests

NASA Astrophysics Data System (ADS)

Jin, Yufang; Randerson, James T.; Goetz, Scott J.; Beck, Pieter S. A.; Loranty, Michael M.; Goulden, Michael L.

2012-03-01

Severity of burning can influence multiple aspects of forest composition, carbon cycling, and climate forcing. We quantified how burn severity affected vegetation recovery and albedo change during early succession in Canadian boreal regions by combining satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Canadian Large Fire Database. We used the MODIS-derived difference Normalized Burn Ratio (dNBR) and initial changes in spring albedo as measures of burn severity. We found that the most severe burns had the greatest reduction in summer MODIS Enhanced Vegetation Index (EVI) in the first year after fire, indicating greater loss of vegetation cover. By 5-8 years after fire, summer EVI for all severity classes had recovered to within 90%-108% of prefire levels. Spring and summer albedo progressively increased during the first 7 years after fire, with more severely burned areas showing considerably larger postfire albedo increases during spring and more rapid increases during summer as compared with moderate- and low-severity burns. After 5-7 years, increases in spring albedo above prefire levels were considerably larger in high-severity burns (0.20 ± 0.06; defined by dNBR percentiles greater than 75%) as compared to changes observed in moderate- (0.16 ± 0.06; for dNBR percentiles between 45% and 75%) or low-severity burns (0.13 ± 0.06; for dNBR percentiles between 20% and 45%). The sensitivity of spring albedo to dNBR was similar in all ecozones and for all vegetation types along gradients of burn severity. These results suggest carbon losses associated with increases in burn severity observed in some areas of boreal forests may be at least partly offset, in terms of climate impacts, by increases in negative forcing associated with changes in surface albedo.

Parental anthropometrics, early growth and the risk of overweight in pre-school children: the Generation R Study.

PubMed

Durmuş, B; Arends, L R; Ay, L; Hokken-Koelega, A C; Raat, H; Hofman, A; Steegers, E A P; Jaddoe, V W V

2013-10-01

There are limited data regarding the associations of both maternal and paternal anthropometrics with longitudinally measured post-natal growth measures in early childhood. To assess the associations of maternal and paternal anthropometrics with growth characteristics and the risk of overweight in pre-school children. Population-based prospective cohort study from early foetal life onwards in the Netherlands. Maternal pre-pregnancy anthropometrics and gestational weight gain, and paternal anthropometrics were related to foetal and post-natal growth measures and the risk of overweight until the age of 4 years. Analyses were based on 5674 mothers, fathers and their children. Both pre-pregnancy maternal and paternal height, weight and body mass index were associated with corresponding foetal and post-natal anthropometric measures. Maternal body mass index had a significantly stronger effect on childhood body mass index than paternal body mass index. As compared to children from parents with normal body mass index, children from two obese parents had an increased risk of overweight at the age of 4 years (odds ratio 6.52 (95% confidence interval 3.44, 12.38). Maternal gestational weight gain was only among mothers with normal body mass index associated with body mass index and the risk of overweight in the children. Maternal and paternal anthropometrics affect early growth in pre-school children differently. Gestational weight gain in mothers without overweight and obesity is related to the risk of overweight in early childhood. © 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.

Characterization of Early Microbial Communities on Volcanic Deposits along a Vegetation Gradient on the Island of Miyake, Japan

PubMed Central

Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

2014-01-01

The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

Study of Maowusu Sandy Land Vegetation Coverage Change Based on Modis Ndvi

NASA Astrophysics Data System (ADS)

Ye, Q.; Liu, H.; Lin, Y.; Han, R.

2018-04-01

This paper selected 2006-2016 MODIS NDVI data with a spatial resolution of 500m and time resolution of 16d, got the 11 years' time series NDVI data of Maowusu sandy land through mosaicking, projection transformation, cutting process in batch. Analysed the spatial and temporal distribution and variation characteristics of vegetation cover in year, season and month time scales by maximum value composite, and unary linear regression analysis. Then, we combined the meteorological data of 33 sites around the sandy area, analysed the response characteristics of vegetation cover change to temperature and precipitation through Pearson correlation coefficient. Studies have shown that: (1) The NDVI value has a stable increase trend, which rate is 0.0075 / a. (2) The vegetation growth have significantly difference in four seasons, the NDVI value of summer > autumn > spring > winter. (3) The NDVI value change trend is conformed to the gauss normal distribution in a year, and it comes to be largest in August, its green season is in April, and yellow season is in the middle of November, the growth period is about 220 d. (4) The vegetation has a decreasing trend from the southeast to the northwest, most part is slightly improved, and Etuokeqianqi improved significantly. (5) The correlation indexes of annual NDVI with temperature and precipitation are -0.2178 and 0.6309, the vegetation growth is mainly affected by precipitation. In this study, a complete vegetation cover analysis and evaluation model for sandy land is established. It has important guiding significance for the sand ecological environment protection.

Seagrass ( Posidonia oceanica) vertical growth as an early indicator of fish farm-derived stress

NASA Astrophysics Data System (ADS)

Marbà, Núria; Santiago, Rocío; Díaz-Almela, Elena; Álvarez, Elvira; Duarte, Carlos M.

2006-04-01

The usefulness of vertical rhizome growth as an early indicator of fish farm impacts to Posidonia oceanica meadows was tested by comparing annual estimates of vertical rhizome growth, quantified retrospectively, at distances ranging between 5 and 1200 m from fish cages at four Mediterranean locations (Cyprus, Greece, Italy and Spain). The studied fish farms had been operating since, at least, 1997, producing between 150 and 1150 tons yr -1 of sea bream ( Sparus aurata) and sea bass ( Dicentrachus labrax), and, at Italy, also sharpsnout sea bream ( Diplodus puntazzo). The reconstructed vertical rhizome growth spanned from 19 to 25 years of growth, depending on sites, and the average vertical rhizome growth before the onset of fish farm operations ranged between 4.48 and 8.79 mm yr -1. The vertical rhizome growth after the onset of farming activities declined significantly ( t-test, P < 0.05) from the control station (at >800 m from the farm; vertical growth rate averaged 6.79, 5.52, 3.89 and 3.70 mm yr -1 at Cyprus, Greece, Italy and Spain control stations, respectively) to the impacted one (at 5-300 m from the farm; vertical growth rate was 4.82, 3.52, 2.77 and 1.92 mm yr -1 at Cyprus, Greece, Italy and Spain impacted stations, respectively) at each farm. Moreover, vertical growth significantly ( t-test, P < 0.05) declined by about twofold following the onset of fish farm operations for the extant meadow nearest to the cages, as well as those supporting intermediate impacts at distances 35-400 m from the cages. Vertical rhizome growth was not significantly affected after the onset of fish farm operations for the meadows located more than 800 m from the farm, except in those from the Italian site, the largest farm. Examination of the time course of vertical growth for individual rhizomes in the areas of the meadow nearest to the farms, except for those at Cyprus, showed that the decline in vertical growth was initiated within the year of the onset of farming

Allelopathic activity and chemical constituents of walnut (Juglans regia) leaf litter in walnut-winter vegetable agroforestry system.

PubMed

Wang, Qian; Xu, Zheng; Hu, Tingxing; Rehman, Hafeez Ur; Chen, Hong; Li, Zhongbin; Ding, Bo; Hu, Hongling

2014-01-01

Walnut agroforestry systems have many ecological and economic benefits when intercropped with cool-season species. However, decomposing leaf litter is one of the main sources of allelochemicals in such systems. In this study, lettuce (Lactuca sativa var. angustata) was grown in the soil incorporated with walnut leaf litter to assess its allelopathic activity. Lettuce growth and physiological processes were inhibited by walnut leaf litter, especially during early growth stage (1-2 euphylla period) or with large amount of litter addition. The plants treated by small amount of leaf litter recovered their growth afterwards, while the inhibition for 180 g leaf litter persisted until harvest. Twenty-eight compounds were identified in the leaf litter, and several of them were reported to be phytotoxic, which may be responsible for the stress induced by walnut leaf litter. Thus, for highest economic value of vegetables such as lettuce, excessive incorporation of leaf litter should be discouraged.

Precommercial thinning: implications of early results from the Tongass-Wide Young-Growth Studies experiments for deer habitat in southeast Alaska

Treesearch

Thomas A. Hanley; Michael H. McClellan; Jeffrey C. Barnard; Mary A. Friberg

2013-01-01

This report documents the results from the first “5-year” round of understory responses to the Tongass-Wide Young-Growth Studies (TWYGS) treatments, especially in relation to their effects on food resources for black-tailed deer (Odocoileus hemionus sitkensis). Responses of understory vegetation to precommercial silviculture experiments after their...

Effects of high versus standard early protein intake on growth of extremely low birth weight infants.

PubMed

Maggio, Luca; Cota, Francesco; Gallini, Francesca; Lauriola, Valeria; Zecca, Chiara; Romagnoli, Costantino

2007-01-01

Early provision of protein has been shown to limit catabolism and could improve growth. Our objective was to determine whether early aggressive protein intake improved growth outcomes of extremely low birth weight (ELBW) infants. ELBW infants were included in the study if they had no major congenital anomalies or renal failure and were still hospitalized at 36 weeks postmenstrual age. In 25 infants (HP) the early protein intake was planned to be 20% greater than in 31 historical controls (SP). The 2 groups were similar in the baseline characteristics. The mean protein intake during the first 14 days of life was significantly greater in the HP group (3.1 +/- 0.2 vs 2.5 +/- 0.2 g/kg/d; P<0.0001). HP group showed lower postnatal weight loss (-3.1%; 95% confidence interval [CI] -5.9, -0.2) and earlier regain of birth weight (-4.1 days; 95% CI -6.6, -1.7). Mean blood urea nitrogen and bicarbonate levels were similar; mean serum glucose level was lower in the HP group (-21,7 mg/dL; 95% CI -41.9,-1.5). HP infants had a reduced fall in weight z score (-0.57; 95% CI -1.01, -0.12) and in length z score (-0.51; 95% CI -0.97, -0.05) from birth to discharge. Early high protein intake was associated with improved weight and length growth outcomes at discharge. These findings highlight the benefits of aggressive protein intake immediately after birth.

Functional and Radiographic Outcomes Following Growth-Sparing Management of Early-Onset Scoliosis.

PubMed

Johnston, Charles E; Tran, Dong-Phuong; McClung, Anna

2017-06-21

In this study, we sought to evaluate radiographic, functional, and quality-of-life outcomes of patients who have completed growth-sparing management of early-onset scoliosis. This prospective study involved patients with early-onset scoliosis who underwent growth-sparing treatment and either "final" fusion or observation for ≥2 years since the last lengthening procedure. Demographics, radiographic parameters, pulmonary function test (PFT) values, and scores of patient-reported assessments (Early-Onset Scoliosis Questionnaire [EOSQ] and Scoliosis Research Society [SRS]-30) were obtained. At the most recent follow-up, patients performed 2 additional functional outcome tests: step-activity monitoring and a treadmill exercise-tolerance test. Twelve patients were evaluated as "graduates" of growth-sparing management of early-onset scoliosis (mean of 37 months since the most recent surgery). The major scoliosis curve measurement averaged 88° before treatment and 47° at the most recent follow-up. T1-S1 height increased from a mean of 22.3 cm to 34.7 cm and T1-T12 height, from 13.3 to 22.3 cm. At the most recent follow-up, the mean forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) as a percentage of the predicted volume were 52.1% and 55.3%, respectively, and were essentially unchanged from the earliest PFT that patients could perform (FEV1 = 53.8% of predicted and FVC = 53.5% of predicted). There was no difference between graduates and controls with respect to activity time or total steps in step-activity monitoring, and in the exercise-tolerance test, graduates walked at the same speed but at a higher heart rate and at a significantly higher (p <0.001) VO2 cost (rate of oxygen consumed per distance traveled). The EOSQ mean score was 102.2 of a possible 120 points, and the SRS mean score was 4.1 of a possible 5 points. A realistic long-term goal for the management of early-onset scoliosis appears to be spine elongation and maintenance of

A Cooking Intervention to Increase Vegetable Consumption by Parents With Children Enrolled in an Early Head Start Home Visiting Program: A Pilot Study in Portland, Oregon, 2013-2014.

PubMed

Izumi, Betty T; Eckhardt, Cara L; Wilson, Dara P; Cahill, Jennifer

2016-12-22

Cooking interventions may improve diet quality. Most cooking interventions are delivered in group settings. Home visiting programs may be an appropriate mechanism for delivering such interventions to low-income families with young children. We conducted a pilot study to test the feasibility of using a cooking intervention delivered by home visitors to improve attitudes and behaviors related to vegetable consumption by low-income parents with children enrolled in a home visiting program. We invited 121 parents with children enrolled in an Early Head Start Home Visiting program in Portland, Oregon, to participate. During 2013-2014, each month for 8 months, home visitors (n = 14) implemented 1 cooking activity plus 1 complementary activity focused on 12 vegetables. We collected pre- and post-intervention data on participants' cooking confidence and whether they tried and liked the selected vegetables. We also measured fidelity to protocol and home visitors' perception of intervention usability. Of 104 participants, 58 provided pre- and post-intervention data. We observed a significant increase in confidence in baking, roasting or grilling vegetables; cooking 6 of 10 vegetables; and trying 7 of 12 vegetables. Nearly all respondents participated in the monthly cooking activity (96%) and complementary activity (94%). Twelve of 14 home visitors reported that the intervention was acceptable, feasible, and easy to understand, and needed systems supports to implement. Cooking interventions may be a feasible approach to improving attitudes and behaviors related to vegetable consumption by low-income families with young children. Additional research is needed to assess the impact of such interventions on vegetable consumption.

Survival and growth of foodborne pathogens in pesticide solutions routinely used in leafy green vegetables and tomato production.

PubMed

Dobhal, Shefali; Zhang, Guodong; Royer, Tom; Damicone, John; Ma, Li Maria

2014-11-01

The consumption of fresh produce has increased tremendously in the past few years as have outbreaks of foodborne illnesses associated with these commodities. Pesticides routinely used in crop production could influence the outcomes of foodborne pathogen contamination of fresh produce. Experiments were performed to determine the effects of pesticides on the survival and growth characteristics of Escherichia coli O157:H7 and Salmonella spp. Eight commercial fungicides and insecticides commonly used for disease and insect pest control on leafy green vegetables and tomatoes were evaluated. Among the pesticides tested, copper hydroxide, acetamiprid, cypermethrin and permethrin were found to be significantly (P < 0.05) inhibitory to pathogens while no effect was observed for chlorothalonil, flonicamid and methoxyfenozide. At the highest concentration tested (2.66%), azoxystrobin had a significant (P < 0.05) stimulatory effect on the growth of E. coli O157:H7 after 24 h incubation. The results indicated that some pesticides can stimulate the growth of human pathogens if contaminated water is used in their preparation, whereas others were likely to inhibit or reduce pathogen populations. This information is helpful in mitigating the risk of microbial contamination in fresh produce, which is critical to public health and safety. © 2014 Society of Chemical Industry.

Research progress of extreme climate and its vegetation response

NASA Astrophysics Data System (ADS)

Cui, Xiaolin; Wei, Xiaoqing; Wang, Tao

2017-08-01

The IPCC’s fifth assessment report indicates that climate warming is unquestionable, the frequency and intensity of extreme weather events may increase, and extreme weather events can destroy the growth conditions of vegetation that is otherwise in a stable condition. Therefore, it is essential to research the formation of extreme weather events and its ecological response, both in terms scientific development and the needs of societal development. This paper mainly examines these issues from the following aspects: (1) the definition of extreme climate events and the methods of studying the associated response of vegetation; (2) the research progress on extreme climate events and their vegetation response; and (3) the future direction of research on extreme climate and its vegetation response.

Early-onset growth hormone deficiency results in diastolic dysfunction in adult-life and is prevented by growth hormone supplementation.

PubMed

Groban, L; Lin, M; Kassik, K A; Ingram, R L; Sonntag, W E

2011-04-01

The primary goal of growth hormone (GH) replacement is to promote linear growth in children with growth hormone deficiency (GHD). GH and insulin-like growth factor-1 (IGF-1) are also known to have roles in cardiac development and as modulators of myocardial structure and function in the adult heart. However, little is known about cardiac diastolic function in young adults with childhood onset GH deficiency in which GH treatment was discontinued following puberty. The aim of the study was to evaluate the effects of long standing GHD and peri-pubertal or continuous GH replacement therapy on diastolic function in the adult dwarf rat. The dwarf rat, which possesses a mutation in a transcription factor necessary for development of the somatotroph, does not exhibit the normal peri-pubertal rise in GH around day 28 and was used to model childhood or early-onset GHD (EOGHD). In another group of male dwarfs, GH replacement therapy was initiated at 4 weeks of age when GH pulsatility normally begins. Ten weeks after initiation of injections, GH-treated dwarf rats were divided into 2 groups; continued treatment with GH for 12 weeks (GH-replete) or treatment with saline for 12 weeks. This latter group models GH supplementation during adolescence with GHD beginning in adulthood (adult-onset GHD; AOGHD). Saline-treated heterozygous (HZ) rats were used as age-matched controls. At 26 weeks of age, cardiac function was assessed using invasive or noninvasive (conventional and tissue Doppler) indices of myocardial contractility and lusitropy. Systolic function, as determined by echocardiography, was similar among groups. Compared with HZ rats and GH-replete dwarfs, the EOGHD group exhibited significant reductions in myocardial relaxation and increases in left ventricular filling pressure, indicative of moderate diastolic dysfunction. This was further associated with a decrease in the cardiac content of sarcoplasmic reticulum Ca(2+) ATPase (SERCA2), one of the important cardiac calcium

Distinguishing plant population and variety with UAV-derived vegetation indices

NASA Astrophysics Data System (ADS)

Oakes, Joseph; Balota, Maria

2017-05-01

Variety selection and seeding rate are two important choice that a peanut grower must make. High yielding varieties can increase profit with no additional input costs, while seeding rate often determines input cost a grower will incur from seed costs. The overall purpose of this study was to examine the effect that seeding rate has on different peanut varieties. With the advent of new UAV technology, we now have the possibility to use indices collected with the UAV to measure emergence, seeding rate, growth rate, and perhaps make yield predictions. This information could enable growers to make management decisions early in the season based on low plant populations due to poor emergence, and could be a useful tool for growers to use to estimate plant population and growth rate in order to help achieve desired crop stands. Red-Green-Blue (RGB) and near-infrared (NIR) images were collected from a UAV platform starting two weeks after planting and continued weekly for the next six weeks. Ground NDVI was also collected each time aerial images were collected. Vegetation indices were derived from both the RGB and NIR images. Greener area (GGA- the proportion of green pixels with a hue angle from 80° to 120°) and a* (the average red/green color of the image) were derived from the RGB images while Normalized Differential Vegetative Index (NDVI) was derived from NIR images. Aerial indices were successful in distinguishing seeding rates and determining emergence during the first few weeks after planting, but not later in the season. Meanwhile, these aerial indices are not an adequate predictor of yield in peanut at this point.

Equilibrium and Balanced Growth of a Vegetative Crop

PubMed Central

SEGINER, IDO

2004-01-01

• Model A previously developed dynamic model, NICOLET, designed to predict growth and nitrate content of a lettuce crop, is subjected to (virtual) constant environmental conditions. For every combination of shoot and root environment, the cell sap, here assumed to reside in the ‘vacuole’ compartment, equilibrates at a certain nitrate concentration level. This, in turn, defines the composition of the crop in terms of carbon and nitrogen content in each of the three compartments of the model. Growth under constant environmental conditions is defined as ‘equilibrium’ growth (EG). If, in addition, the source strengths of carbon and nitrogen balance each other, as well as the sink strength of the growing crop, the growth is said to be ‘balanced’ (BG). • Results It is shown that the range of BG approximately coincides with the range of ‘mild’ nitrogen stress, where reduction in nitrogen availability results in a mild reduction of relative growth rate (RGR). Beyond a certain low nitrate concentration in the cell sap, the N‐stress becomes ‘severe’ and the loss of growth increases considerably. • Conclusions The model is able to mimic the five central observations of many constant‐environment growth‐chamber experiments, namely (1) the initial exponential growth and later decline of the RGR, (2) the constant chemical composition, (3) the equality of the RGR and the relative nutrient supply rate (RNR), (4) the proportionality between the N : C ratio and the RNR, and (5) the proportionality between the water content and the reduced N content. Guidelines for the optimal combination of the shoot and root environments are suggested. PMID:14681082

Monitoring growth condition of spring maize in Northeast China using a process-based model

NASA Astrophysics Data System (ADS)

Wang, Peijuan; Zhou, Yuyu; Huo, Zhiguo; Han, Lijuan; Qiu, Jianxiu; Tan, Yanjng; Liu, Dan

2018-04-01

Early and accurate assessment of the growth condition of spring maize, a major crop in China, is important for the national food security. This study used a process-based Remote-Sensing-Photosynthesis-Yield Estimation for Crops (RS-P-YEC) model, driven by satellite-derived leaf area index and ground-based meteorological observations, to simulate net primary productivity (NPP) of spring maize in Northeast China from the first ten-day (FTD) of May to the second ten-day (STD) of August during 2001-2014. The growth condition of spring maize in 2014 in Northeast China was monitored and evaluated spatially and temporally by comparison with 5- and 13-year averages, as well as 2009 and 2013. Results showed that NPP simulated by the RS-P-YEC model, with consideration of multi-scattered radiation inside the crop canopy, could reveal the growth condition of spring maize more reasonably than the Boreal Ecosystem Productivity Simulator. Moreover, NPP outperformed other commonly used vegetation indices (e.g., Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI)) for monitoring and evaluating the growth condition of spring maize. Compared with the 5- and 13-year averages, the growth condition of spring maize in 2014 was worse before the STD of June and after the FTD of August, and it was better from the third ten-day (TTD) of June to the TTD of July across Northeast China. Spatially, regions with slightly worse and worse growth conditions in the STD of August 2014 were concentrated mainly in central Northeast China, and they accounted for about half of the production area of spring maize in Northeast China. This study confirms that NPP is a good indicator for monitoring and evaluating growth condition because of its capacity to reflect the physiological characteristics of crops. Meanwhile, the RS-P-YEC model, driven by remote sensing and ground-based meteorological data, is effective for monitoring crop growth condition over large areas in a near real

Development of a dynamic growth-death model for Escherichia coli O157:H7 in minimally processed leafy green vegetables.

PubMed

McKellar, Robin C; Delaquis, Pascal

2011-11-15

Escherichia coli O157:H7, an occasional contaminant of fresh produce, can present a serious health risk in minimally processed leafy green vegetables. A good predictive model is needed for Quantitative Risk Assessment (QRA) purposes, which adequately describes the growth or die-off of this pathogen under variable temperature conditions experienced during processing, storage and shipping. Literature data on behaviour of this pathogen on fresh-cut lettuce and spinach was taken from published graphs by digitization, published tables or from personal communications. A three-phase growth function was fitted to the data from 13 studies, and a square root model for growth rate (μ) as a function of temperature was derived: μ=(0.023*(Temperature-1.20))(2). Variability in the published data was incorporated into the growth model by the use of weighted regression and the 95% prediction limits. A log-linear die-off function was fitted to the data from 13 studies, and the resulting rate constants were fitted to a shifted lognormal distribution (Mean: 0.013; Standard Deviation, 0.010; Shift, 0.001). The combined growth-death model successfully predicted pathogen behaviour under both isothermal and non-isothermal conditions when compared to new published data. By incorporating variability, the resulting model is an improvement over existing ones, and is suitable for QRA applications. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Dynamic modeling of vegetation change in arid lands

NASA Technical Reports Server (NTRS)

Robinson, V. B.; Coiner, J. C.; Barringer, T. H.

1982-01-01

A general framework for a digital desertification monitoring system (DDMS) for assessing the worldwide desertification growth rate is presented. The system relies on the development of Landsat derived indicators to identify local processes signalling the growth of arid regions. A study area consisting of the eastern edge of the Niger River delta in Mali was used to characterize three indicators in terms of the covariance of the multispectral scanner (MSS) bands 2 and 4, the correlation of the two bands, and the percent variance expressed by the first eigenvalue. The scenes are imaged multitemporallly in a 400 x 400 pixel array to detect vegetation cover changes. Criteria were defined which characterized the decrease or increase of vegetation. It was determined that the correlation coefficients are the best indicators, and are easily computed.

Effects of a Long-Term Disturbance on Arthropods and Vegetation in Subalpine Wetlands: Manifestations of Pack Stock Grazing in Early versus Mid-Season

PubMed Central

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

2013-01-01

Conclusions regarding disturbance effects in high elevation or high latitude ecosystems based solely on infrequent, long-term sampling may be misleading, because the long winters may erase severe, short-term impacts at the height of the abbreviated growing season. We separated a) long-term effects of pack stock grazing, manifested in early season prior to stock arrival, from b) additional pack stock grazing effects that might become apparent during annual stock grazing, by use of paired grazed and control wet meadows that we sampled at the beginning and end of subalpine growing seasons. Control meadows had been closed to grazing for at least two decades, and meadow pairs were distributed across Sequoia National Park, California, USA. The study was thus effectively a landscape-scale, long-term manipulation of wetland grazing. We sampled arthropods at these remote sites and collected data on associated vegetation structure. Litter cover and depth, percent bare ground, and soil strength had negative responses to grazing. In contrast, fauna showed little response to grazing, and there were overall negative effects for only three arthropod families. Mid-season and long-term results were generally congruent, and the only indications of lower faunal diversity on mid-season grazed wetlands were trends of lower abundance across morphospecies and lower diversity for canopy fauna across assemblage metrics. Treatment x Season interactions almost absent. Thus impacts on vegetation structure only minimally cascaded into the arthropod assemblage and were not greatly intensified during the annual growing season. Differences between years, which were likely a response to divergent snowfall patterns, were more important than differences between early and mid-season. Reliance on either vegetation or faunal metrics exclusively would have yielded different conclusions; using both flora and fauna served to provide a more integrative view of ecosystem response. PMID:23308297

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

PubMed

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

2013-01-01

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

Impact of childhood asthma on growth trajectories in early adolescence: Findings from the Childhood Asthma Prevention Study (CAPS).

PubMed

Movin, Maria; Garden, Frances L; Protudjer, Jennifer L P; Ullemar, Vilhelmina; Svensdotter, Frida; Andersson, David; Kruse, Andreas; Cowell, Chris T; Toelle, Brett G; Marks, Guy B; Almqvist, Catarina

2017-04-01

Understanding the associations between childhood asthma and growth in early adolescence by accounting for the heterogeneity of growth during puberty has been largely unexplored. The objective was to identify sex-specific classes of growth trajectories during early adolescence, using a method which takes the heterogeneity of growth into account and to evaluate the association between childhood asthma and different classes of growth trajectories in adolescence. Our longitudinal study included participants with a family history of asthma born during 1997-1999 in Sydney, Australia. Hence, all participants were at high risk for asthma. Asthma status was ascertained at 8 years of age using data from questionnaires and lung function tests. Growth trajectories between 11 and 14 years of age were classified using a latent basis growth mixture model. Multinomial regression analyses were used to evaluate the association between asthma and the categorized classes of growth trajectories. In total, 316 participants (51.6% boys), representing 51.3% of the entire cohort, were included. Sex-specific classes of growth trajectories were defined. Among boys, asthma was not associated with the classes of growth trajectories. Girls with asthma were more likely than girls without asthma to belong to a class with later growth (OR: 3.79, 95% CI: 1.33, 10.84). Excluding participants using inhaled corticosteroids or adjusting for confounders did not significantly change the results for either sex. We identified sex-specific heterogeneous classes of growth using growth mixture modelling. Associations between childhood asthma and different classes of growth trajectories were found for girls only. © 2016 Asian Pacific Society of Respirology.

Inversion of Farmland Soil Moisture in Large Region Based on Modified Vegetation Index

NASA Astrophysics Data System (ADS)

Wang, J. X.; Yu, B. S.; Zhang, G. Z.; Zhao, G. C.; He, S. D.; Luo, W. R.; Zhang, C. C.

2018-04-01

Soil moisture is an important parameter for agricultural production. Efficient and accurate monitoring of soil moisture is an important link to ensure the safety of agricultural production. Remote sensing technology has been widely used in agricultural moisture monitoring because of its timeliness, cyclicality, dynamic tracking of changes in things, easy access to data, and extensive monitoring. Vegetation index and surface temperature are important parameters for moisture monitoring. Based on NDVI, this paper introduces land surface temperature and average temperature for optimization. This article takes the soil moisture in winter wheat growing area in Henan Province as the research object, dividing Henan Province into three main regions producing winter wheat and dividing the growth period of winter wheat into the early, middle and late stages on the basis of phenological characteristics and regional characteristics. Introducing appropriate correction factor during the corresponding growth period of winter wheat, correcting the vegetation index in the corresponding area, this paper establishes regression models of soil moisture on NDVI and soil moisture on modified NDVI based on correlation analysis and compare models. It shows that modified NDVI is more suitable as a indicator of soil moisture because of the better correlation between soil moisture and modified NDVI and the higher prediction accuracy of the regression model of soil moisture on modified NDVI. The research in this paper has certain reference value for winter wheat farmland management and decision-making.

Parental care mitigates carry-over effects of poor early conditions on offspring growth

USGS Publications Warehouse

Auer, Sonya K.; Martin, Thomas E.

2017-01-01

Poor developmental conditions can have long-lasting negative effects on offspring phenotypes, but impacts often differ among species. Contrasting responses may reflect disparities in experimental protocols among single-species studies or inherent differences among species in their sensitivity to early conditions and/or ability to mitigate negative impacts. We used a common experimental protocol to assess and compare the role of parental care in mitigating effects of poor early conditions on offspring among 4 sympatric bird species in the wild. We experimentally induced low incubation temperatures and examined effects on embryonic developmental rates, hatching success, nestling growth rates, and parental responses. We examined the generality of these effects across 4 species that differ in their phylogenetic history, breeding ecology, and life histories. We found that cooling led to delayed hatching in all species, but carry-over effects on offspring differed among species. Parents of some but not all species increased their offspring provisioning rates in response to experimental cooling with critical benefits for offspring growth rates. Our study shows for the first time that species exhibit clear differences in the degree to which they are affected by poor early conditions. Observed differences among species demonstrate that parental care is a critical mechanism for mitigating potential negative effects on offspring and suggest that parental responses may be constrained to varying degrees by ecology and life histories.

The Southern High Plains: A history of vegetation, 1540 to present

Treesearch

David B. Wester

2007-01-01

Considerable documentary evidence is available about the historic vegetation of the Southern High Plains (SHP). Accounts spanning about 350 years (from the earliest European explorers in the 1540s to scientists working in the later 19th and early 20th centuries), however, lead to vague and sometimes contradictory conclusions about the nature of this vegetation. The...

Contraction and stress-dependent growth shape the forebrain of the early chicken embryo.

PubMed

Garcia, Kara E; Okamoto, Ruth J; Bayly, Philip V; Taber, Larry A

2017-01-01

During early vertebrate development, local constrictions, or sulci, form to divide the forebrain into the diencephalon, telencephalon, and optic vesicles. These partitions are maintained and exaggerated as the brain tube inflates, grows, and bends. Combining quantitative experiments on chick embryos with computational modeling, we investigated the biophysical mechanisms that drive these changes in brain shape. Chemical perturbations of contractility indicated that actomyosin contraction plays a major role in the creation of initial constrictions (Hamburger-Hamilton stages HH11-12), and fluorescent staining revealed that F-actin is circumferentially aligned at all constrictions. A finite element model based on these findings shows that the observed shape changes are consistent with circumferential contraction in these regions. To explain why sulci continue to deepen as the forebrain expands (HH12-20), we speculate that growth depends on wall stress. This idea was examined by including stress-dependent growth in a model with cerebrospinal fluid pressure and bending (cephalic flexure). The results given by the model agree with observed morphological changes that occur in the brain tube under normal and reduced eCSF pressure, quantitative measurements of relative sulcal depth versus time, and previously published patterns of cell proliferation. Taken together, our results support a biphasic mechanism for forebrain morphogenesis consisting of differential contractility (early) and stress-dependent growth (late). Copyright © 2016 Elsevier Ltd. All rights reserved.

Eating a rainbow. Introducing vegetables in the first years of life in 3 European countries.

PubMed

Ahern, Sara M; Caton, Samantha J; Bouhlal, Sofia; Hausner, Helene; Olsen, Annemarie; Nicklaus, Sophie; Møller, Per; Hetherington, Marion M

2013-12-01

Low vegetable consumption in children is a concern in many EU countries, fewer than one fifth of children in Europe consume the WHO recommended amounts. Systematic studies demonstrate that experience with a variety of vegetables early in childhood can promote later consumption as early dietary habits often track into adulthood. This study examined pre-school children's experience with vegetables across three European countries in order to assess cultural differences, effects of age and culinary practices. Mothers of pre-school children (N=234) in the UK (N=71), Denmark (N=93) and France (N=70) completed a survey assessing parental and infant familiarity, frequency of offering and liking for 56 vegetables as well as preparation techniques for these vegetables. Analyses revealed that although children aged 25-36 months had been introduced to the greatest number of vegetables, children aged 6-12 months were offered vegetables more frequently and had a higher reported liking for these vegetables. UK children's liking was related to frequency of maternal intake and frequency of offering. Denmark had introduced the greatest number of vegetables and offered vegetables more frequently than both the UK and France. Choice of preparation methods differed between countries while choice of seasonings was similar. Results suggest increasing variety and frequency of vegetable offering between 6 and 12 months, when children are most receptive, may promote vegetable consumption in children. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intrauterine growth restriction and placental gene expression in severe preeclampsia, comparing early-onset and late-onset forms.

PubMed

Nevalainen, Jaana; Skarp, Sini; Savolainen, Eeva-Riitta; Ryynänen, Markku; Järvenpää, Jouko

2017-10-26

To evaluate placental gene expression in severe early- or late-onset preeclampsia with intrauterine growth restriction compared to controls. Chorionic villus sampling was conducted after cesarean section from the placentas of five women with early- or late-onset severe preeclampsia and five controls for each preeclampsia group. Microarray analysis was performed to identify gene expression differences between the groups. Pathway analysis showed over-representation of gene ontology (GO) biological process terms related to inflammatory and immune response pathways, platelet development, vascular development, female pregnancy and reproduction in early-onset preeclampsia. Pathways related to immunity, complement and coagulation cascade were overrepresented in the hypergeometric test for the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Ten genes (ABI3BP, C7, HLA-G, IL2RB, KRBOX1, LRRC15, METTL7B, MPP5, RFLNB and SLC20A) had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to early controls. There were 362 genes that had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to late-onset preeclampsia group including ABI3BP, C7, HLA-G and IL2RB. There are significant differences in placental gene expression between severe early- and late-onset preeclampsia when both are associated with intrauterine growth restriction. ABI3BP, C7, HLA-G and IL2RB might contribute to the development of early form of severe preeclampsia.

Changes in the structure of bacterial complexes of vegetable crops in the course of their growth on a cultivated soddy-podzolic soil

NASA Astrophysics Data System (ADS)

Dobrovol'skaya, T. G.; Khusnetdinova, K. A.

2017-11-01

The dynamics of population density and taxonomic structure of epiphytic bacterial communities on the leaves and roots of potatoes, carrots, and beets have been studied. Significant changes take place in the ontogenesis of these vegetables with substitution of hydrolytic bacteria for eccrisotrophic bacteria feeding on products of plant exosmosis. The frequency of domination of representatives of different taxa of epiphytic bacteria on the studied plants has been determined for the entire period of their growth. Bacteria of different genera have been isolated from the aboveground and underground organs of vegetables; their functions are discussed. It is shown that the taxonomic structure of bacterial communities in the soil under studied plants is not subjected to considerable changes and is characterized by the domination of typical soil bacteria— Arthrobacter and bacilli—with the appearance of Rhodococcus as a codominant at the end of the season (before harvesting).

Feedback dynamics of grazing lawns: Coupling vegetation change with animal growth

USGS Publications Warehouse

Person, Brian T.; Herzog, M.P.; Ruess, Roger W.; Sedinger, J.S.; Anthony, R. Michael; Babcock, C.A.

2003-01-01

We studied the effects of grazing by Black Brant (Branta bernicla nigricans) geese (hereafter Brant) on plant community zonation and gosling growth between 1987 and 2000 at a nesting colony in southwestern Alaska. The preferred forage of Brant, Carex subspathacea, is only found as a grazing lawn. An alternate forage species, C. ramenskii, exists primarily as meadow but also forms grazing lawns when heavily grazed. We mowed plots of ungrazed C. ramenskii meadows to create swards that Brant could select and maintain as grazing lawns. Fecal counts were higher on mowed plots than on control plots in the year after plots were mowed. Both nutritional quality and aboveground biomass of C. ramenskii in mowed plots were similar to that of C. subspathacea grazing lawns. The areal extent of grazing lawns depends in part on the population size of Brant. High Brant populations can increase the areal extent of grazing lawns, which favors the growth of goslings. Grazing lawns increased from 3% to 8% of surface area as the areal extent of C. ramenskii meadows declined between 1991 and 1999. Gosling mass was lower early in this time period due to density dependent effects. As the goose population stabilized, and area of grazing lawns increased, gosling mass increased between 1993 and 1999. Because larger goslings have increased survival, higher probability of breeding, and higher fecundity, herbivore-mediated changes in the distribution grazing lawn extent may result in a numerical increase of the population within the next two decades.

Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence.

PubMed

Bormann, Jörg; Tudzynski, Paul

2009-12-01

The putative Claviceps purpurea homologue of the Saccharomyces cerevisiae stretch-activated calcium ion channel Mid1 was investigated for its role in vegetative growth, differentiation and pathogenicity on rye (Secale cereale). Gene replacement mutants of Cl. purpurea mid1 were not affected in polar growth and branching in axenic culture but showed a significantly reduced growth rate. The growth defect could not be complemented by Ca(2+) supplementation, in contrast to mid1 mutants in yeast, but the altered sensitivity of the mutants to changes in external and internal Ca(2+) concentrations indicates some role of Mid1 in Ca(2+) homeostasis. The major effect of mid1 deletion, however, was the complete loss of virulence: infected rye plants showed no disease symptoms at all. Detailed analyses of in vitro-infected rye ovaries demonstrated that the Deltamid1 mutants had multiple apical branches and were unable to infect the host tissue, suggesting that Mid1 is essential for generating the necessary mechanical force for penetration. This is believed to be the first report of an essential role for a Mid1 homologue in the virulence of a plant-pathogenic fungus.