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Sample records for early successional stage

  1. Soil nematode communities are ecologically more mature beneath late- than early-successional stage biological soil crusts

    USGS Publications Warehouse

    Darby, B.J.; Neher, D.A.; Belnap, J.

    2007-01-01

    Biological soil crusts are key mediators of carbon and nitrogen inputs for arid land soils and often represent a dominant portion of the soil surface cover in arid lands. Free-living soil nematode communities reflect their environment and have been used as biological indicators of soil condition. In this study, we test the hypothesis that nematode communities are successionally more mature beneath well-developed, late-successional stage crusts than immature, early-successional stage crusts. We identified and enumerated nematodes by genus from beneath early- and late-stage crusts from both the Colorado Plateau, Utah (cool, winter rain desert) and Chihuahuan Desert, New Mexico (hot, summer rain desert) at 0-10 and 10-30 cm depths. As hypothesized, nematode abundance, richness, diversity, and successional maturity were greater beneath well-developed crusts than immature crusts. The mechanism of this aboveground-belowground link between biological soil crusts and nematode community composition is likely the increased food, habitat, nutrient inputs, moisture retention, and/or environmental stability provided by late-successional crusts. Canonical correspondence analysis of nematode genera demonstrated that nematode community composition differed greatly between geographic locations that contrast in temperature, precipitation, and soil texture. We found unique assemblages of genera among combinations of location and crust type that reveal a gap in scientific knowledge regarding empirically derived characterization of dominant nematode genera in deserts soils and their functional role in a crust-associated food web. ?? 2006 Elsevier B.V. All rights reserved.

  2. Spatial distribution patterns of ammonia-oxidizing archaea abundance in subtropical forests at early and late successional stages

    PubMed Central

    Chen, Jie; Zhang, Hui; Liu, Wei; Lian, Juyu; Ye, Wanhui; Shen, Weijun

    2015-01-01

    Characterizing the spatial distribution patterns of soil microorganisms is helpful in understanding the biogeochemical processes they perform, but has been less studied relative to those of macroorganisms. In this study, we investigated and compared the spatially explicit distribution patterns of ammonia-oxidizing archaea (AOA) abundance and the influential factors between an early (ES) and a late successional (LS) subtropical forest stand. The average AOA abundance, vegetational attributes, and soil nutrient contents were mostly greater in the LS than the ES stand (P = 0.085 or smaller), but their spatial variations were more pronounced in the ES than the LS stand. The spatial distribution patches of AOA abundance were smaller and more irregular in the ES stand (patch size <50 m) than in the LS stand (patch size about 120 m). Edaphic and vegetational variables contributed more to the spatial variations of AOA abundance for the ES (9.3%) stand than for LS stand, whereas spatial variables (MEMs) were the main contributors (62%) for the LS stand. These results suggest that environmental filtering likely influence the spatial distribution of AOA abundance at early successional stage more than that at late successional stage, while spatial dispersal is dominant at late successional stage. PMID:26565069

  3. Climate extremes can drive biological assemblages to early successional stages compared to several mild disturbances

    PubMed Central

    Sanz-Lázaro, Carlos

    2016-01-01

    Extreme climatic events have a major role in the structuring of biological communities, and their occurrence is expected to increase due to climate change. Here I use a manipulative approach to test the effects of extreme storm events on rocky mid-shore assemblages. This study shows that an extreme storm can cause more negative effects than several mild storms, primarily by bringing the biological assemblages towards early stages of succession. This finding contrasts with the effects of clustering of climatic events due to climate change, which are expected to mitigate its ecological impacts. Thus, the ecological consequences of climatic events that are influenced by climate change may have contrasting effects depending on the features that are considered. These results have relevant implications in the forecasting of the ecological consequences of climate change and should be considered when designing measures to mitigate its effects. PMID:27527612

  4. Climate extremes can drive biological assemblages to early successional stages compared to several mild disturbances

    NASA Astrophysics Data System (ADS)

    Sanz-Lázaro, Carlos

    2016-08-01

    Extreme climatic events have a major role in the structuring of biological communities, and their occurrence is expected to increase due to climate change. Here I use a manipulative approach to test the effects of extreme storm events on rocky mid-shore assemblages. This study shows that an extreme storm can cause more negative effects than several mild storms, primarily by bringing the biological assemblages towards early stages of succession. This finding contrasts with the effects of clustering of climatic events due to climate change, which are expected to mitigate its ecological impacts. Thus, the ecological consequences of climatic events that are influenced by climate change may have contrasting effects depending on the features that are considered. These results have relevant implications in the forecasting of the ecological consequences of climate change and should be considered when designing measures to mitigate its effects.

  5. Top predators affect the composition of naive protist communities, but only in their early-successional stage.

    PubMed

    Zander, Axel; Gravel, Dominique; Bersier, Louis-Félix; Gray, Sarah M

    2016-02-01

    Introduced top predators have the potential to disrupt community dynamics when prey species are naive to predation. The impact of introduced predators may also vary depending on the stage of community development. Early-succession communities are likely to have small-bodied and fast-growing species, but are not necessarily good at defending against predators. In contrast, late-succession communities are typically composed of larger-bodied species that are more predator resistant relative to small-bodied species. Yet, these aspects are greatly neglected in invasion studies. We therefore tested the effect of top predator presence on early- and late-succession communities that were either naive or non-naive to top predators. We used the aquatic community held within the leaves of Sarracenia purpurea. In North America, communities have experienced the S. purpurea top predator and are therefore non-naive. In Europe, this predator is not present and its niche has not been filled, making these communities top-predator naive. We collected early- and late-succession communities from two non-naive and two naive sites, which are climatically similar. We then conducted a common-garden experiment, with and without the presence of the top predator, in which we recorded changes in community composition, body size spectra, bacterial density, and respiration. We found that the top predator had no statistical effect on global measures of community structure and functioning. However, it significantly altered protist composition, but only in naive, early-succession communities, highlighting that the state of community development is important for understanding the impact of invasion.

  6. Phyllostomid Bat Occurrence in Successional Stages of Neotropical Dry Forests

    PubMed Central

    Avila-Cabadilla, Luis Daniel; Stoner, Kathryn Elizabeth; Nassar, Jafet M.; Espírito-Santo, Mario M.; Alvarez-Añorve, Mariana Yolotl; Aranguren, Carla I.; Henry, Mickael; González-Carcacía, José A.; Dolabela Falcão, Luiz A.; Sanchez-Azofeifa, Gerardo Arturo

    2014-01-01

    Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for

  7. Early Successional Microhabitats Allow the Persistence of Endangered Plants in Coastal Sand Dunes

    PubMed Central

    2015-01-01

    Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems. PMID:25835390

  8. Early successional microhabitats allow the persistence of endangered plants in coastal sand dunes.

    PubMed

    Pardini, Eleanor A; Vickstrom, Kyle E; Knight, Tiffany M

    2015-01-01

    Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems.

  9. Aboveground-belowground biodiversity linkages differ in early and late successional temperate forests

    PubMed Central

    Li, Hui; Wang, Xugao; Liang, Chao; Hao, Zhanqing; Zhou, Lisha; Ma, Sam; Li, Xiaobin; Yang, Shan; Yao, Fei; Jiang, Yong

    2015-01-01

    Understanding ecological linkages between above- and below-ground biota is critical for deepening our knowledge on the maintenance and stability of ecosystem processes. Nevertheless, direct comparisons of plant-microbe diversity at the community level remain scarce due to the knowledge gap between microbial ecology and plant ecology. We compared the α- and β- diversities of plant and soil bacterial communities in two temperate forests that represented early and late successional stages. We documented different patterns of aboveground-belowground diversity relationships in these forests. We observed no linkage between plant and bacterial α-diversity in the early successional forest, and even a negative correlation in the late successional forest, indicating that high bacterial α-diversity is not always linked to high plant α-diversity. Beta-diversity coupling was only found at the late successional stage, while in the early successional forest, the bacterial β-diversity was closely correlated with soil property distances. Additionally, we showed that the dominant competitive tree species in the late successional forest may play key roles in driving forest succession by shaping the soil bacterial community in the early successional stage. This study sheds new light on the potential aboveground-belowground linkage in natural ecosystems, which may help us understand the mechanisms that drive ecosystem succession. PMID:26184121

  10. Changes in Forest Soil Properties in Different Successional Stages in Lower Tropical China

    PubMed Central

    Li, Yuelin; Yang, Fangfang; Ou, Yangxu; Zhang, Deqiang; Liu, Juxiu; Chu, Guowei; Zhang, Yaru; Otieno, Dennis; Zhou, Guoyi

    2013-01-01

    Background Natural forest succession often affects soil physical and chemical properties. Selected physical and chemical soil properties were studied in an old-growth forest across a forest successional series in Dinghushan Nature Reserve, Southern China. Methodology/Principal Findings The aim was to assess the effects of forest succession change on soil properties. Soil samples (0–20 cm depth) were collected from three forest types at different succession stages, namely pine (Pinus massoniana) forest (PMF), mixed pine and broadleaf forest (PBMF) and monsoon evergreen broadleaf forest (MEBF), representing early, middle and advanced successional stages respectively. The soil samples were analyzed for soil water storage (SWS), soil organic matter (SOM), soil microbial biomass carbon (SMBC), pH, NH4+-N, available potassium (K), available phosphorus (P) and microelements (available copper (Cu), available zinc (Zn), available iron (Fe) and available boron (B)) between 1999 and 2009. The results showed that SWS, SOM, SMBC, Cu, Zn, Fe and B concentrations were higher in the advanced successional stage (MEBF stage). Conversely, P and pH were lower in the MEBF but higher in the PMF (early successional stage). pH, NH4+-N, P and K declined while SOM, Zn, Cu, Fe and B increased with increasing forest age. Soil pH was lower than 4.5 in the three forest types, indicating that the surface soil was acidic, a stable trend in Dinghushan. Conclusion/Significance These findings demonstrated significant impacts of natural succession in an old-growth forest on the surface soil nutrient properties and organic matter. Changes in soil properties along the forest succession gradient may be a useful index for evaluating the successional stages of the subtropical forests. We caution that our inferences are drawn from a pseudo-replicated chronosequence, as true replicates were difficult to find. Further studies are needed to draw rigorous conclusions regarding on nutrient dynamics in

  11. Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert

    USGS Publications Warehouse

    Housman, D.C.; Powers, H.H.; Collins, A.D.; Belnap, J.

    2006-01-01

    Biological soil crusts (cyanobacteria, mosses and lichens collectively) perform essential ecosystem services, including carbon (C) and nitrogen (N) fixation. Climate and land-use change are converting later successional soil crusts to early successional soil crusts with lower C and N fixation rates. To quantify the effect of such conversions on C and N dynamics in desert ecosystems we seasonally measured diurnal fixation rates in different biological soil crusts. We classified plots on the Colorado Plateau (Canyonlands) and Chihuahuan Desert (Jornada) as early (Microcoleus) or later successional (Nostoc/Scytonema or Placidium/Collema) and measured photosynthesis (Pn), nitrogenase activity (NA), and chlorophyll fluorescence (Fv/Fm) on metabolically active (moist) soil crusts. Later successional crusts typically had greater Pn, averaging 1.2-1.3-fold higher daily C fixation in Canyonlands and 2.4-2.8-fold higher in the Jornada. Later successional crusts also had greater NA, averaging 1.3-7.5-fold higher daily N fixation in Canyonlands and 1.3-25.0-fold higher in the Jornada. Mean daily Fv/Fm was also greater in later successional Canyonlands crusts during winter, and Jornada crusts during all seasons except summer. Together these findings indicate conversion of soil crusts back to early successional stages results in large reductions of C and N inputs into these ecosystems.

  12. Chemical variation in Jacobaea vulgaris is influenced by the interaction of season and vegetation successional stage.

    PubMed

    Carvalho, Sabrina; Macel, Mirka; Mulder, Patrick P J; Skidmore, Andrew; van der Putten, Wim H

    2014-03-01

    Knowledge on spatio-temporal dynamics of plant primary and secondary chemistry under natural conditions is important to assess how plant defence varies in real field conditions. Plant primary and secondary chemistry is known to vary with both season and vegetation successional stage, however, in few studies these two sources of variation have been examined in combination. Here we examine variations in primary and secondary chemistry of Jacobaea vulgaris (Asteraceae) throughout the growing season in early, mid, and late stages of secondary succession following land abandonment using a well-established chronosequence in The Netherlands. We investigated primary and secondary chemistry of both leaves and flowers, in order to determine if patterns during seasonal (phenological) development may differ among successional stages. The chemical concentration of primary and secondary chemistry compounds in J. vulgaris varied throughout the season and was affected by vegetation succession stage. Concentrations of pyrrolizidine alkaloid (PA) tertiary-amines were highest in flowers during early Summer and in fields that had been abandoned ten to twenty years ago. PA N-oxide concentrations of both leaves and flowers, on the other hand increased with the progression of both season and succession. In Spring and early Summer chlorophyll concentrations were highest, especially in the oldest fields of the chronosequence. During phenological development, nitrogen concentration increased in flowers and decreased in leaves revealing allocation of nutrients from vegetative to reproductive plant parts throughout the growing season. The highest concentrations of N-oxides and chlorophylls were detected in older fields. Thus, our results suggest that variations in plant patterns of nutritional and defence compounds throughout the growing season are depending on successional context.

  13. Experimental Analysis of Grazing by the Mayfly Meridialaris chiloeensis on Different Successional Stages of Stream Periphyton

    NASA Astrophysics Data System (ADS)

    Díaz Villanueva, Verónica; Modenutti, Beatriz

    2004-07-01

    In this study we determined grazing effects of the South Andean endemic mayfly Meridialaris chiloeensis on periphyton at different stages of successional development. Grazing effects were studied through a two-factor experimental design (colonization stages X grazer density) in a stream-side channel in spring and winter. Our results showed an absence of proportionality between grazer density and periphyton decline in response to grazers at low and intermediate levels of periphytic biomass; however, when periphyton biomass was high a direct inverse relationship was observed between post-grazing biomass and grazer density. The relationship between periphytic algae (chlorophyll a concentration) and periphyton (total periphytic ash-free dry mass) (C/OM index) was used as an estimation of the autotrophic fraction in the total periphyton matrix. Grazing did not alter the C/OM index indicating that both autotrophic and heterotrophic fractions of the periphyton components were reduced in the same proportion. Ordination of samples using the relative abundance of diatom species showed that herbivore effect was less evident at intermediate and late stage of colonization than at early one. These results support the statement that the outcome of the herbivore-periphyton interaction may depend on the successional stage of the periphyton community. In spring Fragilaria pinnata relative abundance, on the basis of cell counts, was reduced by grazing and Nitzschia palea was enhanced. In the winter experiment, grazing decreased Achnanthes minutissima relative abundance. (

  14. Carbon stocks and dynamics at different successional stages in an Afromontane tropical forest

    NASA Astrophysics Data System (ADS)

    Nyirambangutse, Brigitte; Zibera, Etienne; Uwizeye, Félicien K.; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

    2017-03-01

    As a result of different types of disturbance, forests are a mixture of stands at different stages of ecological succession. Successional stage is likely to influence forest productivity and carbon storage, linking the degree of forest disturbance to the global carbon cycle and climate. Although tropical montane forests are an important part of tropical forest ecosystems (ca. 8 %, elevation > 1000 m a.s.l.), there are still significant knowledge gaps regarding the carbon dynamics and stocks of these forests, and how these differ between early (ES) and late successional (LS) stages. This study examines the carbon (C) stock, relative growth rate (RGR) and net primary production (NPP) of ES and LS forest stands in an Afromontane tropical rainforest using data from inventories of quantitatively important ecosystem compartments in fifteen 0.5 ha plots in Nyungwe National Park in Rwanda. The total C stock was 35 % larger in LS compared to ES plots due to significantly larger above-ground biomass (AGB; 185 and 76 Mg C ha-1 in LS and ES plots), while the soil and root C stock (down to 45 cm depth in the mineral soil) did not significantly differ between the two successional stages (178 and 204 Mg C ha-1 in LS and ES plots). The main reasons for the difference in AGB were that ES trees had significantly lower stature and wood density compared to LS trees. However, ES and LS stands had similar total NPP (canopy, wood and roots of all plots ˜ 9.4 Mg C ha-1) due to counterbalancing effects of differences in AGB (higher in LS stands) and RGR (higher in ES stands). The AGB in the LS plots was considerably higher than the average value reported for old-growth tropical montane forest of south-east Asia and Central and South America at similar elevations and temperatures, and of the same magnitude as in tropical lowland forest of these regions. The results of this study highlight the importance of accounting for disturbance regimes and differences in wood density and allometry of

  15. Determining successional stage of temperate coniferous forests with Landsat satellite data

    SciTech Connect

    Fiorella, M.; Ripple, W.J. )

    1993-02-01

    Thematic Mapper (TM) digital imagery was used to map forest successional stages and to evaluate spectral differences between old-growth and mature forests in the central Cascade Range of Oregon. Relative sun incidence values were incorporated into the successional stage classification to compensate for topographic induced variation. Relative sun incidence improved the classification accuracy of young successional stages, but did not improve the classification accuracy of older, closed canopy forest classes or overall accuracy. TM bands 1, 2, and 4; the normalized difference vegetation index; and TM 4/3, 4/5, and 4/7 band ratio values for od-growth forests were found to be significantly lower than the values of mature forests. The Tasseled Cap features of brightness, greenness, and wetness also had significantly lower old-growth values as compared to mature forest values. 35 refs.

  16. Breeding, Early-Successional Bird Response to Forest Harvests for Bioenergy

    PubMed Central

    Grodsky, Steven M.; Moorman, Christopher E.; Fritts, Sarah R.; Castleberry, Steven B.; Wigley, T. Bently

    2016-01-01

    Forest regeneration following timber harvest is a principal source of habitat for early-successional birds and characterized by influxes of early-successional vegetation and residual downed woody material. Early-successional birds may use harvest residues for communication, cover, foraging, and nesting. Yet, increased market viability of woody biomass as bioenergy feedstock may intensify harvest residue removal. Our objectives were to: 1) evaluate effects of varying intensities of woody biomass harvest on the early-successional bird community; and (2) document early-successional bird use of harvest residues in regenerating stands. We spot-mapped birds from 15 April– 15 July, 2012–2014, in six woody biomass removal treatments within regenerating stands in North Carolina (n = 4) and Georgia (n = 4), USA. Treatments included clearcut harvest followed by: (1) traditional woody biomass harvest with no specific retention target; (2) 15% retention with harvest residues dispersed; (3) 15% retention with harvest residues clustered; (4) 30% retention with harvest residues dispersed; (5) 30% retention with harvest residues clustered; and (6) no woody biomass harvest (i.e., reference site). We tested for treatment-level effects on breeding bird species diversity and richness, early-successional focal species territory density (combined and individual species), counts of breeding birds detected near, in, or on branches of harvest piles/windrows, counts of breeding bird behaviors, and vegetation composition and structure. Pooled across three breeding seasons, we delineated 536 and 654 territories and detected 2,489 and 4,204 birds in the North Carolina and Georgia treatments, respectively. Woody biomass harvest had limited or short-lived effects on the early-successional, breeding bird community. The successional trajectory of vegetation structure, rather than availability of harvest residues, primarily drove avian use of regenerating stands. However, many breeding bird

  17. Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones

    NASA Astrophysics Data System (ADS)

    Gil-Sotres, F.; Miralles, I.; Canton-Castilla, Y.; Domingo, F.; Leiros, M. C.; Trasar-Cepeda, C.

    2012-04-01

    Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones I. Miralles1, F. Gil-Sotres2, Y. Cantón-Castilla3, F. Domingo1, M.C. Leirós2, C. Trasar-Cepeda4 1 Experimental Estation of Arid Zones (CSIC), E-04230 La Cañada de San Urbano, Almería, Spain. 2 Departamento Edafología y Química Agrícola, Grupo de Evaluación de la Calidad del Suelo, Unidad Asociada CSIC, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain. 3 University of Almería, Departamento de Edafología y Química Agrícola, E-04230-La Cañada de San Urbano, Almería, Spain. 4 Departamento Bioquímica del Suelo, IIAG-CSIC, Apartado 122, E-15708 Santiago de Compostela, Spain. Crusts (BSCs) are formed by a close association between soil particles and cyanobacteria, algae, lichens, bryophytes and microfungi in varying proportions. Their habitat is within or immediately on top of the uppermost millimetres of the soil and are the predominant surface cover in arid and semiarid zones. Among the diverse functions developed by BSCs in the ecosystem (hydrology, erosion, soil properties, etc.), one of the most important is its role in nutrient cycling. Within arid and semiarid environments, BSCs have been termed 'mantles of fertility' being considered hotspots of biogeochemical inputs, fixing C, N and P above- and below-ground. However, there are differences in N and C fixation rates between BSCs types. Early successional BSCs, dominated by cyanobacterial species, fix lower quantities of C and N than mature BSCs dominated by lichens. Although the positive effects of BSCs on biogeochemical soil cycles are widely accepted, no previous studies have evaluated the activities of the enzymes involved in C, N and P cycles of BSCs and how they are affected by the successional stage of the BSC. In this work, performed in the Tabernas desert (SE Spain), we studied the hydrolase enzymes

  18. Assessing level of development and successional stages in biological soil crusts with biological indicators.

    PubMed

    Lan, Shubin; Wu, Li; Zhang, Delu; Hu, Chunxiang

    2013-08-01

    Biological soil crusts (BSCs) perform vital ecosystem services, but the difference in biological components or developmental level still affects the rate and type of these services. In order to differentiate crust successional stages in quantity and analyze the relationship between crust developmental level and successional stages, this work determined several biological indicators in a series of different developmental BSCs in the Shapotou region of China. The results showed that crust developmental level (level of development index) can be well indicated by crust biological indicators. Photosynthetic biomass was the most appropriate to differentiate crust successional stages, although both photosynthetic biomass and respiration intensity increased with the development and succession of BSCs. Based on of the different biological compositions, BSCs were quantificationally categorized into different successional stages including cyanobacterial crusts (lichen and moss coverages <20 %), lichen crusts (lichen coverage >20 % but moss coverage <20 %), semi-moss crusts (moss coverage >20 % but <75 %), and moss crusts (moss coverage >75 %). In addition, it was found that cyanobacterial and microalgal biomass first increased as cyanobacterial crusts formed, then decreased when lots of mosses emerged on the crust surface; however nitrogen-fixing cyanobacteria and heterotrophic microbes increased in the later developmental BSCs. The structural adjustment of biological components in the different developmental BSCs may reflect the requirement of crust survival and material transition.

  19. Encouraging family forest owners to create early successional wildlife habitat in Southern New England.

    PubMed

    Buffum, Bill; Modisette, Christopher; McWilliams, Scott R

    2014-01-01

    Encouraging family forest owners to create early successional habitat is a high priority for wildlife conservation agencies in the northeastern USA, where most forest land is privately owned. Many studies have linked regional declines in wildlife populations to the loss of early successional habitat. The government provides financial incentives to create early successional habitat, but the number of family forest owners who actively manage their forests remains low. Several studies have analyzed participation of family forest owners in federal forestry programs, but no study to date has focused specifically on creation of wildlife habitat. The objective of our study was to analyze the experience of a group of wildlife-oriented family forest owners who were trained to create early successional habitat. This type of family forest owners represents a small portion of the total population of family forest owners, but we believe they can play an important role in creating wildlife habitat, so it is important to understand how outreach programs can best reach them. The respondents shared some characteristics but differed in terms of forest holdings, forestry experience and interest in earning forestry income. Despite their strong interest in wildlife, awareness about the importance of early successional habitat was low. Financial support from the federal government appeared to be important in motivating respondents to follow up after the training with activities on their own properties: 84% of respondents who had implemented activities received federal financial support and 47% would not have implemented the activities without financial assistance. In order to mobilize greater numbers of wildlife-oriented family forest owners to create early successional habitat we recommend focusing outreach efforts on increasing awareness about the importance of early successional habitat and the availability of technical and financial assistance.

  20. Spatial analysis of early successional, temperate forest community structure

    NASA Astrophysics Data System (ADS)

    Walker, R. H.; Williams, C. A.; MacLean, R. G.; Epstein, H. E.; Vanderhoof, M. K.

    2013-12-01

    The global importance of sequestration of carbon by temperate forests makes characterizing the regrowth of these forests post-disturbance both ecologically and economically important. High intensity disturbances, such as logging, result in substantial alteration of community composition post-disturbance, creating the potential for alterations to the cycling of carbon, water, and nutrients in the ecosystem. Because logging pressure in New England continues to increase, understanding how forest ecosystems in this region respond to disturbance is crucial. This study aims to characterize interspecies interactions within New England forests by identifying synchronous and asynchronous colocation of species following a disturbance. To accomplish this, line-intercept surveys of vegetation were conducted in a clearcut forest stand located within the Harvard Forest LTER site. Survey data collected two (2010) and five (2013) years post-clearcut were analyzed using a one-dimensional Ripley's K. From 2010 to 2013, an increase in the number of interspecies relationships was observed, indicating the development of community structure. Additionally, the analysis found an increase in total vegetative cover from 2010 to 2013, and also found the majority of observed interspecies relationships to be asynchronous relationships. Together, these results imply an increase in resource competition that had the potential to drive the increase in community structure. Specifically, an increase in community structure led to the development of three distinct sub-communities: homogenous fern, tree seedling canopy over ground cover, and shrub dominated. This creates a patchy landscape in the early successional forest that allows for high species diversity (Shannon's H = 2.455). Based on the results of the Ripley's K analyses, species demonstrated definite patterns of synchronicity and asynchronicity based on both specific species interactions as well as functional group interactions. These

  1. Mapping Successional Stages in a Wet Tropical Forest Using Landsat ETM+ and Forest Inventory Data

    NASA Technical Reports Server (NTRS)

    Goncalves, Fabio G.; Yatskov, Mikhail; dos Santos, Joao Roberto; Treuhaft, Robert N.; Law, Beverly E.

    2010-01-01

    In this study, we test whether an existing classification technique based on the integration of Landsat ETM+ and forest inventory data enables detailed characterization of successional stages in a wet tropical forest site. The specific objectives were: (1) to map forest age classes across the La Selva Biological Station in Costa Rica; and (2) to quantify uncertainties in the proposed approach in relation to field data and existing vegetation maps. Although significant relationships between vegetation height entropy (a surrogate for forest age) and ETM+ data were detected, the classification scheme tested in this study was not suitable for characterizing spatial variation in age at La Selva, as evidenced by the error matrix and the low Kappa coefficient (12.9%). Factors affecting the performance of the classification at this particular study site include the smooth transition in vegetation structure between intermediate and advanced successional stages, and the low sensitivity of NDVI to variations in vertical structure at high biomass levels.

  2. Determining successional stage of temperate coniferous forests with Landsat satellite data

    NASA Technical Reports Server (NTRS)

    Fiorella, Maria; Ripple, William J.

    1995-01-01

    Thematic Mapper (TM) digital imagery was used to map forest successional stages and to evaluate spectral differences between old-growth and mature forests in the central Cascade Range of Oregon. Relative sun incidence values were incorporated into the successional stage classification to compensate for topographic induced variation. Relative sun incidence improved the classification accuracy of young successional stages, but did not improve the classification accuracy of older, closed canopy forest classes or overall accuracy. TM bands 1, 2, and 4; the normalized difference vegetation index (NDVI); and TM 4/3, 4/5, and 4/7 band ratio values for old-growth forests were found to be significantly lower than the values of mature forests (P less than or equal to 0.010). Wetness and the TM 4/5 and 4/7 band ratios all had low correlations to relative sun incidence (r(exp 2) less than or equal to 0.16). The TM 4/5 band ratio was named the 'structural index' (SI) because of its ability to distinguish between mature and old-growth forests and its simplicity.

  3. Importance of early successional habitat to ruffed grouse and American woodcock

    USGS Publications Warehouse

    Dessecker, D.R.; McAuley, D.G.

    2001-01-01

    Ruffed grouse (Bonasa umbellus) and American woodcock (Scolopax minor) provide millions of days of recreation each year for people in the eastern United States (U.S). These popular game birds depend on early successional forest habitats throughout much of the year. Ruffed grouse and woodcock populations are declining in the eastern United States as an abundance of shrub-dominated and young forest habitats decrease in most of the region. Continued decreases in early successional forest habitats are likely on nonindustrial private forest lands as ownership fragmentation increases and tract size decreases and on public forest lands due to societal attitudes toward proactive forest management, especially even-age treatments.

  4. Arbuscular mycorrhizal fungal networks vary throughout the growing season and between successional stages.

    PubMed

    Bennett, Alison Elizabeth; Daniell, Tim John; Öpik, Maarja; Davison, John; Moora, Mari; Zobel, Martin; Selosse, Marc-André; Evans, Darren

    2013-01-01

    To date, few analyses of mutualistic networks have investigated successional or seasonal dynamics. Combining interaction data from multiple time points likely creates an inaccurate picture of the structure of networks (because these networks are aggregated across time), which may negatively influence their application in ecosystem assessments and conservation. Using a replicated bipartite mutualistic network of arbuscular mycorrhizal (AM) fungal-plant associations, detected using large sample numbers of plants and AM fungi identified through molecular techniques, we test whether the properties of the network are temporally dynamic either between different successional stages or within the growing season. These questions have never been directly tested in the AM fungal-plant mutualism or the vast majority of other mutualisms. We demonstrate the following results: First, our examination of two different successional stages (young and old forest) demonstrated that succession increases the proportion of specialists within the community and decreases the number of interactions. Second, AM fungal-plant mutualism structure changed throughout the growing season as the number of links between partners increased. Third, we observed shifts in associations between AM fungal and plant species throughout the growing season, potentially reflecting changes in biotic and abiotic conditions. Thus, this analysis opens up two entirely new areas of research: 1) identifying what influences changes in plant-AM fungal associations in these networks, and 2) what aspects of temporal variation and succession are of general importance in structuring bipartite networks and plant-AM fungal communities.

  5. Arbuscular Mycorrhizal Fungal Networks Vary throughout the Growing Season and between Successional Stages

    PubMed Central

    Bennett, Alison Elizabeth; Daniell, Tim John; Öpik, Maarja; Davison, John; Moora, Mari; Zobel, Martin; Selosse, Marc-André; Evans, Darren

    2013-01-01

    To date, few analyses of mutualistic networks have investigated successional or seasonal dynamics. Combining interaction data from multiple time points likely creates an inaccurate picture of the structure of networks (because these networks are aggregated across time), which may negatively influence their application in ecosystem assessments and conservation. Using a replicated bipartite mutualistic network of arbuscular mycorrhizal (AM) fungal-plant associations, detected using large sample numbers of plants and AM fungi identified through molecular techniques, we test whether the properties of the network are temporally dynamic either between different successional stages or within the growing season. These questions have never been directly tested in the AM fungal-plant mutualism or the vast majority of other mutualisms. We demonstrate the following results: First, our examination of two different successional stages (young and old forest) demonstrated that succession increases the proportion of specialists within the community and decreases the number of interactions. Second, AM fungal-plant mutualism structure changed throughout the growing season as the number of links between partners increased. Third, we observed shifts in associations between AM fungal and plant species throughout the growing season, potentially reflecting changes in biotic and abiotic conditions. Thus, this analysis opens up two entirely new areas of research: 1) identifying what influences changes in plant-AM fungal associations in these networks, and 2) what aspects of temporal variation and succession are of general importance in structuring bipartite networks and plant-AM fungal communities. PMID:24358265

  6. Mercury sequestration by rainforests: The influence of microclimate and different successional stages.

    PubMed

    Teixeira, Daniel C; Lacerda, Luiz D; Silva-Filho, Emmanoel V

    2017-02-01

    Mercury (Hg) concentrations in tropical forest soils and litter are up to 10 times higher than those from temperate and boreal forests. The majority of Hg that has been stored in tropical soils, as the forest is left intact, could be trapped in deeper layers of soil and only small quantities are exported to water bodies. The quantitative approach to the Hg cycle in tropical forests is uncommon; the South America Atlantic Forest indeed is a hotspot for species conservation and also seems to be for the Hg's cycle. This study reports on a biannual dynamics of Hg through different species assemblage of different successional stages in this biome, based on 24 litter traps used to collect litterfall from 3 different successional stages under a rainforest located at Brazilian Southeast. The mean Hg litterfall flux obtained was 6.1 ± 0.15 μg ha(-1) yr(-1), while the mean Hg concentration in litter was 57 ± 16 ng g(-1) and the accumulation of Hg via litterfall flux was 34.6 ± 1.2 μg m(-2) yr(-1). These inventories are close to those found for tropical areas in the Amazon, but they were lower than those assessed for Atlantic Forest biome studies. These low concentrations are related to the remoteness of the area from pollution sources and probably to the climatic limitation, due to the altitude effects over the forest's eco-physiology. The mercury fluxes found in each different successional stage, correlated with time variations of global radiation, suggesting a mandatory role of the forest primary production over Hg deposition to the soil.

  7. Sensitivity of understorey bird species in two different successional stages of the lowland Atlantic Forest, Brazil.

    PubMed

    Loures-Ribeiro, Alan; Manhães, Marco A; Dias, Manoel M

    2011-09-01

    The Atlantic Forest has a high destruction rate and there is little information available on some aspects of the neotropical bird biology. Changes in environment are important factors that affect the resources available to birds. We compared the species sensitivity level of understorey birds in two areas in distinct successional stages (primary and secondary sections). Two 100 ha plots of lowland Atlantic Forest were analysed between August and December 2006. Among 25 bird species recorded, thirteen had lower abundance in secondary forest, two in primary forest, and ten had not clear tendency. According to the criteria used, the percentages for species with low, and medium and high sensitivity to habitat change were 44% and 56%, respectively. The number of species was not associated with the endemism level or foraging strata. Results show the importance of knowing bird species' sensitivity level with regard to habitat modification, and not only forest fragmentation.

  8. Proximity signal and shade avoidance differences between early and late successional trees.

    PubMed

    Gilbert, I R; Jarvis, P G; Smith, H

    2001-06-14

    Competitive interactions between plants determine the success of individuals and species. In developing forests, competition for light is the predominant factor. Shade tolerators acclimate photosynthetically to low light and are capable of long-term survival under the shade cast by others, whereas shade avoiders rapidly dominate gaps but are overtaken in due course by shade-tolerant, later successional species. Shade avoidance results from the phytochrome-mediated perception of far-red radiation (700-800 nm) scattered from the leaves of neighbours, provides early warning of shading, and induces developmental responses that, when successful, result in the overgrowth of those neighbours. Shade tolerators cast a deep shade, whereas less-tolerant species cast light shade, and saplings tend to have high survivorship in shade cast by conspecific adults, but high rates of mortality when shaded by more-tolerant species. Here we report a parallel relationship in which the shade-avoidance responses of three tree species are inversely proportional to proximity signals generated by those species. On this basis, early successional species generate small proximity signals but react strongly to them, whereas late successional species react weakly but generate strong signals.

  9. Invasive Earthworms and Forest Successional Stage Interact to Impact Plant Litter Inputs and Particulate Organic Matter Chemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The landscapes colonized by invasive earthworms in the eastern U.S. are often patchworks of forest stands in various stages of successional development. We established six field sites in tulip poplar dominated forests in the Smithsonian Environmental Research Center Forest (SERC), MD, that span you...

  10. Variation in the effects of burial in different peatland successional stages on seed survival of four wetland species

    NASA Astrophysics Data System (ADS)

    Egawa, Chika

    2017-01-01

    The availability of viable seeds in soil helps to determine the success of ecological restoration in disturbed habitats. Although seed survival in soil generally increases with an increase in burial depth, whether the effects of burial on seed survival are comparable across different sites is unclear. In this study, I tested the hypothesis that the positive effects of burial on seed survival decrease as vegetation develops through succession. Four wetland species, Drosera rotundifolia, Lobelia sessilifolia, Rhynchospora alba and Moliniopsis japonica, were used for the study. The four species differ in their light requirement for germination; i.e., D. rotundifolia, L. sessilifolia and R. alba germinate best in light, whereas M. japonica germinates equally well in light and darkness. The seeds of these species were buried for two years at three depths (litter, 0 and 4 cm) in three successional stages with different amounts of vegetation and litter in a post-mined peatland. The photosynthetically active radiation (PAR) and temperature at each of litter layer, 0 cm and 4 cm depths were measured for each successional stage. The between-depth differences in PAR and temperature fluctuations decreased as succession progressed. For the three light-demanding species, burial promoted seed survival more in the initial successional stage than in the later successional stages, whereas for M. japonica, burial promoted seed survival equally in all successional stages. This study revealed significant variation in the effects of burial on seed survival, particularly for light-sensitive seeds, and that the soil surface layers in vegetated sites can contain persistent seeds, which could be used as a seed source in restoration.

  11. Anthropogenic Habitats Facilitate Dispersal of an Early Successional Obligate: Implications for Restoration of an Endangered Ecosystem

    PubMed Central

    Amaral, Katrina E.; Palace, Michael; O’Brien, Kathleen M.; Fenderson, Lindsey E.; Kovach, Adrienne I.

    2016-01-01

    Landscape modification and habitat fragmentation disrupt the connectivity of natural landscapes, with major consequences for biodiversity. Species that require patchily distributed habitats, such as those that specialize on early successional ecosystems, must disperse through a landscape matrix with unsuitable habitat types. We evaluated landscape effects on dispersal of an early successional obligate, the New England cottontail (Sylvilagus transitionalis). Using a landscape genetics approach, we identified barriers and facilitators of gene flow and connectivity corridors for a population of cottontails in the northeastern United States. We modeled dispersal in relation to landscape structure and composition and tested hypotheses about the influence of habitat fragmentation on gene flow. Anthropogenic and natural shrubland habitats facilitated gene flow, while the remainder of the matrix, particularly development and forest, impeded gene flow. The relative influence of matrix habitats differed between study areas in relation to a fragmentation gradient. Barrier features had higher explanatory power in the more fragmented site, while facilitating features were important in the less fragmented site. Landscape models that included a simultaneous barrier and facilitating effect of roads had higher explanatory power than models that considered either effect separately, supporting the hypothesis that roads act as both barriers and facilitators at all spatial scales. The inclusion of LiDAR-identified shrubland habitat improved the fit of our facilitator models. Corridor analyses using circuit and least cost path approaches revealed the importance of anthropogenic, linear features for restoring connectivity between the study areas. In fragmented landscapes, human-modified habitats may enhance functional connectivity by providing suitable dispersal conduits for early successional specialists. PMID:26954014

  12. Anthropogenic Habitats Facilitate Dispersal of an Early Successional Obligate: Implications for Restoration of an Endangered Ecosystem.

    PubMed

    Amaral, Katrina E; Palace, Michael; O'Brien, Kathleen M; Fenderson, Lindsey E; Kovach, Adrienne I

    2016-01-01

    Landscape modification and habitat fragmentation disrupt the connectivity of natural landscapes, with major consequences for biodiversity. Species that require patchily distributed habitats, such as those that specialize on early successional ecosystems, must disperse through a landscape matrix with unsuitable habitat types. We evaluated landscape effects on dispersal of an early successional obligate, the New England cottontail (Sylvilagus transitionalis). Using a landscape genetics approach, we identified barriers and facilitators of gene flow and connectivity corridors for a population of cottontails in the northeastern United States. We modeled dispersal in relation to landscape structure and composition and tested hypotheses about the influence of habitat fragmentation on gene flow. Anthropogenic and natural shrubland habitats facilitated gene flow, while the remainder of the matrix, particularly development and forest, impeded gene flow. The relative influence of matrix habitats differed between study areas in relation to a fragmentation gradient. Barrier features had higher explanatory power in the more fragmented site, while facilitating features were important in the less fragmented site. Landscape models that included a simultaneous barrier and facilitating effect of roads had higher explanatory power than models that considered either effect separately, supporting the hypothesis that roads act as both barriers and facilitators at all spatial scales. The inclusion of LiDAR-identified shrubland habitat improved the fit of our facilitator models. Corridor analyses using circuit and least cost path approaches revealed the importance of anthropogenic, linear features for restoring connectivity between the study areas. In fragmented landscapes, human-modified habitats may enhance functional connectivity by providing suitable dispersal conduits for early successional specialists.

  13. Hyperspectral reflectance of leaves and flowers of an outbreak species discriminates season and successional stage of vegetation

    NASA Astrophysics Data System (ADS)

    Carvalho, Sabrina; Schlerf, Martin; van der Putten, Wim H.; Skidmore, Andrew K.

    2013-10-01

    Spectral reflectance can be used to assess large-scale performances of plants in the field based on plant nutrient balance as well as composition of defence compounds. However, plant chemical composition is known to vary with season - due to its phenology - and it may even depend on the succession stage of its habitat. Here we investigate (i) how spectral reflectance could be used to discriminate successional and phenological stages of Jacobaea vulgaris in both leaf and flower organs and (ii) if chemical content estimation by reflectance is flower or leaf dependent. We used J. vulgaris, which is a natural outbreak plant species on abandoned arable fields in north-western Europe and studied this species in a chronosequence representing successional development during time since abandonment. The chemical content and reflectance between 400 and 2500 nm wavelengths of flowers and leaves were measured throughout the season in fields of different successional ages. The data were analyzed with multivariate statistics for temporal discrimination and estimation of chemical contents in both leaf and flower organs. Two main effects were revealed by spectral reflectance measurements: (i) both flower and leaf spectra show successional and seasonal changes, but the pattern is complex and organ specific (ii) flower head pyrrolizidine alkaloids, which are involved in plant defence against herbivores, can be detected through hyperspectral reflectance.We conclude that spectral reflectance of both leaves and flowers can provide information on plant performance during season and successional stages. As a result, remote sensing studies of plant performance in complex field situations will benefit from considering hyperspectral reflectance of different plant organs. This approach may enable more detailed studies on the link between spectral information and plant defence dynamics both aboveground and belowground.

  14. Evaporation and transpiration differences among successional stages of Tropical Dry Forest, Santa Rosa National Park, Costa Rica

    NASA Astrophysics Data System (ADS)

    Jiménez-Rodríguez, César D.; Calvo-Alvarado, Julio

    2016-04-01

    Seasonal environments in the tropics show strong responses to changes in precipitation regimes. The monthly water availability is the main trigger for ecological responses as flowering, fructification, leaf sprouting and senescence. Among these environments, the tropical dry forests (TDF) depends directly on the soil water availability, defining the forest growing season despite the forest characteristics. However, within the same ecosystem is possible to find differences in the water fluxes due to forest age. The TDF located in Santa Rosa National Park (SRNP) in Costa Rica; shows a particular matrix of secondary forest patches varying in age, structure, and species composition allowing us to evaluate the water fluxes differences among successional stages of TDF. Three permanent plots of 1000.0 m2 were selected from the Tropi-Dry project. Each plot characterized a specific successional stage of this ecosystem varying in forest structure and age. Every location was equipped to measure the hourly soil water content and forest growth, while the meteorological conditions were collected by the meteorological station of the national park. The data was collected from December 2005 to June 2009 however, due to data gaps and quality control the data analysis includes only the hydrological years between 2006 and 2009. The soil water content was measured at three depths in each plot (10, 30 and 40 cm) to determine the real evapotranspiration from the forest. The precipitation along these three years shows strong variations registering 326.5 mm-1yr-1 in the first year up to 3004.0 mm-1yr-1 during the last year, these strong changes are influenced by the ENOS phenomena in the region. Regardless the precipitation amounts the evapotranspiration do not differ strongly on a yearly basis, were 726.7 mm-1yr-1, 675.1 mm-1yr-1 and 751.6 mm-1yr-1 were exported to the atmosphere by the early, intermediate and late stages of TDF secondary forest. The yearly strong differences in

  15. Overwinter survival of neotropical migratory birds in early successional and mature tropical forests

    USGS Publications Warehouse

    Conway, C.J.; Powell, G.V.N.; Nichols, J.D.

    1995-01-01

    Many Neotropical migratory species inhabit both mature and early successional forest on their wintering grounds, yet comparisons of survival rates between habitats are lacking. Consequently, the factors affecting habitat suitability for Neotropical migrants and the potential effects of tropical deforestation on migrants are not well understood. We estimated over-winter survival and capture probabilities of Wood Thrush (Hylocichla mustelina), Ovenbird (Seiurus aurocapillus), Hooded Warbler (Wilsonia citrina), and Kentucky Warbler (Oporomis formosus) inhabiting two common tropical habitat types, mature and early-successional forest. Our results suggest that large differences (for example, ratio of survival rates (gamma) < 0.85) in overwinter survival between these habitats do not exist for any of these species. Age ratios did not differ between habitats, but males were more common in forest habitats and females more common in successional habitats for Hooded Warblers and Kentucky Warblers. Future research on overwinter survival should address the need for age- and sex-specific survival estimates before we can draw strong conclusions regarding winter habitat suitability. Our estimates of over-winter survival extrapolated to annual survival rates that were generally lower than previous estimates of annual survival of migratory birds. Capture probability differed between habitats for Kentucky Warblers, but our results provide strong evidence against large differences in capture probability between habitats for Wood Thrush, Hooded Warblers, and Ovenbirds. We found no temporal or among site differences in survival or capture probability for any of the four species. Additional research is needed to examine the effects of winter habitat use on survival during migration and between-winter survival.

  16. Projected Effects of CO2 Enrichment on Community Dynamics and Carbon Cycling in an Early-successional Forest

    NASA Astrophysics Data System (ADS)

    Miller, A. D.; Dietze, M.; DeLucia, E. H.; Anderson-Teixeira, K. J.

    2013-12-01

    Early-successional forests are strong carbon (C) sinks that play an important role in the global C cycle. Elevated CO2 may alter C cycling in regenerating forests both directly through ecophysiological mechanisms and indirectly through altered community dynamics, which may be particularly important in early successional forests with high community turnover. Thus, to discriminate impacts of CO2 enrichment on C cycles in regenerating forests it is necessary to characterize how the physiological and successional mechanisms that regulate the C cycle are altered by climate change. Because species are known to display differential growth stimulus under CO2 enrichment, and these species-specific effects are grouped by classic plant functional type, we hypothesize that successional trajectories will be altered in high CO2 forests, compared to forests regenerating under historic climatic conditions. To test this hypothesis, we use the Ecosystem Demography model (ED2), a height- and successional-structured terrestrial biosphere model to predict possible effects of elevated CO2 on forest succession. Using data from the Duke Free Air CO2 Enrichment (FACE) experiment and a nearby chronosequence of pine forests to parameterize and evaluate the model, we use ED2 to project how plant demography and competition will react to elevated CO2 over a 50-100 year time frame. We evaluate the sensitivity of model results to a variety of model configurations, and demonstrate that the outcomes are largely robust to structural uncertainty regarding assumptions about nitrogen limitation and water availability. The model predicts that elevated CO2 will alter C cycling directly through ecophysiological effect and indirectly through altered community dynamics, which in turn affect C cycling. For instance, late-successional hardwood species will receive more benefit on average from elevated CO2, than early-successional hardwoods. After 50 years of 550 ppm CO2, late-successional hardwoods experience

  17. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    PubMed Central

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland. PMID:25110722

  18. Facilitative and inhibitory effect of litter on seedling emergence and early growth of six herbaceous species in an early successional old field ecosystem.

    PubMed

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m(-2), litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  19. Soil uptake of carbonyl sulfide in subtropical forests with different successional stages in south China

    NASA Astrophysics Data System (ADS)

    Yi, Zhigang; Wang, Xinming; Sheng, Guoying; Zhang, Deqiang; Zhou, Guoyi; Fu, Jiamo

    2007-04-01

    The uptake rates of carbonyl sulfide (COS) by soils in subtropical forests with different successional stages were measured using static chambers in Dinghushan Biosphere Reserve (DBR) in south China from July 2004 to March 2005. The three typical tropical forests studied included monsoon evergreen broad-leaf forest (BF), pine and broad-leaf mixed forest (MF) and pine forest (PF), representing forests with different succession stages in the region. COS exchange rates were also compared between the plots with litter-fall remaining (plots L) and those with litter-fall removed (plots S) in each forest. Results showed that these forest soils all acted as sinks for COS with exchange rates of -1.22 to -11.82 pmol m-2 s-1. The MF in the midsuccessional stage had significantly higher uptake rates, and the mean exchange rates in the BF, MF, and PF were -3.90, -4.77, and -3.65 pmol m-2 s-1, respectively. COS uptake rates at plots L were higher than those at plots S. Mean COS fluxes were significantly higher in March (-6.06 pmol m-2 s-1) than those in July (-3.60 pmol m-2 s-1), August (-3.82 pmol m-2 s-1), September (-3.45 pmol m-2 s-1), and October (-3.54 pmol m-2 s-1). Significant correlation was observed between the COS uptake rates and soil respiration rates or microbial biomass, indicating that microbial activity was an important factor controlling the soil uptake of COS. Significant correlations between COS fluxes and initial COS mixing ratios were only observed in the BF and MF. COS fluxes showed no correlation with soil temperature or water content alone in any of the three forests, but do correlate well with soil temperature and water content together in polynomial forms with an order of 2.

  20. Demographic variation across successional stages and their effects on the population dynamics of the neotropical palm Euterpe precatoria.

    PubMed

    Otárola, Mauricio Fernández; Avalos, Gerardo

    2014-06-01

    • Premise of the study: Environmental heterogeneity is a strong selective force shaping adaptation and population dynamics across temporal and spatial scales. Natural and anthropogenic gradients influence the variation of environmental and biotic factors, which determine population demography and dynamics. Successional gradients are expected to influence demographic parameters, but the relationship between these gradients and the species life history, habitat requirements, and degree of variation in demographic traits remains elusive.• Methods: We used the palm Euterpe precatoria to test the effect of successional stage on plant demography within a continuous population. We calculated demographic parameters for size stages and performed matrix analyses to investigate the demographic variation within primary and secondary forests of La Selva, Costa Rica.• Key results: We observed differences in mortality and recruitment of small juveniles between primary and secondary forests. Matrix models described satisfactorily the chronosequence of population changes, which were characterized by high population growth rate in disturbed areas, and decreased growth rate in old successional forests until reaching stability.• Conclusions: Different demographic parameters can be expressed in contiguous subpopulations along a gradient of successional stages with important consequences for population dynamics. Demographic variation superimposed on these gradients contributes to generate subpopulations with different demographic composition, density, and ecological properties. Therefore, the effects of spatial variation must be reconsidered in the design of demographic analyses of tropical palms, which are prime examples of subtle local adaptation. These considerations are crucial in the implementation of management plans for palm species within spatially complex and heterogeneous tropical landscapes.

  1. Early-successional ectomycorrhizal fungi effectively support extracellular enzyme activities and seedling nitrogen accumulation in mature forests.

    PubMed

    Nicholson, Bailey A; Jones, Melanie D

    2017-04-01

    After stand-replacing disturbance, regenerating conifer seedlings become colonized by different ectomycorrhizal fungi (EMF) than the locally adapted EMF communities present on seedlings in mature forests. We studied whether EMF species that colonized subalpine fir (Abies lasiocarpa) seedlings in clearcuts differed from those that colonized seedlings in adjacent mature forests with respect to mycorrhizoplane extracellular enzyme activities (EEAs) and N status of the seedlings. We tested two alternate hypotheses: (1) that EEAs would differ between the two EMF communities, with higher activities associated with forest-origin communities, and (2) that acclimation to soil environment was considerable enough that EEAs would be determined primarily by the soil type in which the ectomycorrhizas were growing. Naturally colonized fir seedlings were reciprocally transplanted between clearcuts and forests, carrying different EMF communities with them. EEAs were influenced more by destination environment than by EMF community. EEAs were as high in early-successional as in late-successional communities in both destination environments. Buds of clearcut-origin seedlings had the same or higher N contents as forest seedlings after a growing season in either environment. These results indicate that (i) symbiotic EMF and/or their associated microbial communities demonstrate substantial ability to acclimate to new field environments; (ii) the ability to produce organic matter-degrading enzymes is not a trait that necessarily distinguishes early- and late-successional EMF communities in symbiosis; (iii) early-successional EMF are as capable of supporting seedling N accumulation in forest soils as late-successional EMF; and (iv) disturbed ecosystems where early-successional EMF are present should have high resilience for organic matter degradation.

  2. Understanding landowner intentions to create early successional forest habitat in the northeastern United States

    USGS Publications Warehouse

    Dayer, Ashley A.; Stedman, Richard C.; Allred, Shorna B.; Rosenberg, Kenneth V.; Fuller, Angela K.

    2016-01-01

    Early successional forest habitat (ESH) and associated wildlife species in the northeastern United States are in decline. One way to help create early successional forest conditions is engaging private forest landowners in even-aged forest management because their limited participation may have contributed to declines in ESH for wildlife species of high conservation concern. We applied the reasoned action approach from social psychology to predict intentions of landowners in the 13-county Southern Tier of New York State, USA, to conduct patch-cuts, which is a type of even-aged forest management. We tested the predictive ability of the model using data from a mail survey of landowners conducted from November 2010 to January 2011. Landowner intention to conduct patch-cuts was high (55% of respondents), with attitude being the strongest direct predictor of behavioral intention. Our results suggest that patch-cutting intentions are most likely expressed by landowners who think the behavior is good for their land and wildlife, believe in positive outcomes of land and wildlife management, belong to a game wildlife organization, and have conducted patch-cuts in the past. Strategies to engage more landowners in ESH management will have the highest likelihood of success if outreach efforts focus on influencing behavioral beliefs and subsequently attitudes, possibly working with game wildlife organizations to communicate a unified message for habitat conservation, including the importance of maintaining and creating ESH. Our results demonstrate the importance of social science research to increase the likelihood that conservation targets for declining wildlife species are met. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  3. Relative importance of early-successional forests and shrubland habitats to mammals in the northeastern United States

    USGS Publications Warehouse

    Fuller, T.K.; DeStefano, S.

    2003-01-01

    The majority of the 60 native terrestrial mammal species that reside in the northeastern United States (US) utilize resources from several habitats on a seasonal basis. However, as many as 20 species demonstrate some preference for early-successional forests, shrublands, or old-field habitats. A few of these (e.g. lagomorphs) can be considered obligate users of these habitats, and the specialist carnivores (e.g. felids) that prey on them may consequently also prefer such habitats. Other mammal species that prefer these habitats certainly depend on them to lesser and varying degrees; thus, the consequences of reducing or eliminating early-successional forests, shrublands, or old-field habitats across the landscape will likely have varying demographic consequences, and thus importance, to those species. ?? 2003 Elsevier B.V. All rights reserved.

  4. Early stage colon cancer.

    PubMed

    Freeman, Hugh James

    2013-12-14

    Evidence has now accumulated that colonoscopy and removal of polyps, especially during screening and surveillance programs, is effective in overall risk reduction for colon cancer. After resection of malignant pedunculated colon polyps or early stage colon cancers, long-term repeated surveillance programs can also lead to detection and removal of asymptomatic high risk advanced adenomas and new early stage metachronous cancers. Early stage colon cancer can be defined as disease that appears to have been completely resected with no subsequent evidence of involvement of adjacent organs, lymph nodes or distant sites. This differs from the clinical setting of an apparent "curative" resection later pathologically upstaged following detection of malignant cells extending into adjacent organs, peritoneum, lymph nodes or other distant sites, including liver. This highly selected early stage colon cancer group remains at high risk for subsequent colon polyps and metachronous colon cancer. Precise staging is important, not only for assessing the need for adjuvant chemotherapy, but also for patient selection for continued surveillance. With advanced stages of colon cancer and a more guarded outlook, repeated surveillance should be limited. In future, novel imaging technologies (e.g., confocal endomicroscopy), coupled with increased pathological recognition of high risk markers for lymph node involvement (e.g., "tumor budding") should lead to improved staging and clinical care.

  5. Beyond ectomycorrhizal bipartite networks: projected networks demonstrate contrasted patterns between early- and late-successional plants in Corsica

    PubMed Central

    Taudiere, Adrien; Munoz, François; Lesne, Annick; Monnet, Anne-Christine; Bellanger, Jean-Michel; Selosse, Marc-André; Moreau, Pierre-Arthur; Richard, Franck

    2015-01-01

    The ectomycorrhizal (ECM) symbiosis connects mutualistic plants and fungal species into bipartite networks. While links between one focal ECM plant and its fungal symbionts have been widely documented, systemic views of ECM networks are lacking, in particular, concerning the ability of fungal species to mediate indirect ecological interactions between ECM plant species (projected-ECM networks). We assembled a large dataset of plant–fungi associations at the species level and at the scale of Corsica using molecular data and unambiguously host-assigned records to: (i) examine the correlation between the number of fungal symbionts of a plant species and the average specialization of these fungal species, (ii) explore the structure of the plant–plant projected network and (iii) compare plant association patterns in regard to their position along the ecological succession. Our analysis reveals no trade-off between specialization of plants and specialization of their partners and a saturation of the plant projected network. Moreover, there is a significantly lower-than-expected sharing of partners between early- and late-successional plant species, with fewer fungal partners for early-successional ones and similar average specialization of symbionts of early- and late-successional plants. Our work paves the way for ecological readings of Mediterranean landscapes that include the astonishing diversity of below-ground interactions. PMID:26539201

  6. Supplemental planting of early successional tree species during bottomland hardwood afforestation

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.; Outcalt, Kenneth W.

    2002-01-01

    Reforestation of former bottom land hardwood forests that have been cleared for agriculture (i.e., afforestation) has historically emphasized planting heavy-seeded oaks (Quercus spp.) and pecans (Carya spp.). These species are slow to develop vertical forest structure. However, vertical forest structure is key to colonization of afforested sites by forest birds. Although early-successional tree species often enhance vertical structure, few of these species invade afforested sites that are distant from seed sources. Furthermore, many land mangers are reluctant to establish and maintain stands of fast-growing plantation trees. Therefore, on 40 afforested bottomland sites, we supplemented heavy-seeded seedlings with 8 patches of fast-growing trees: 4 patches of 12 eastern cottonwood (Populus deltoides) stem cuttings and 4 patches of 12 American sycamore (Platanus occidentalis) seedlings. To enhance survival and growth, tree patches were subjected to 4 weed control treatments: (1) physical weed barriers, (2) chemical herbicide, (3) both physical and chemical weed control, or (4) no weed control. Overall, first-year survival of cottonwood and sycamore was 25 percent and 47 percent, respectively. Second-year survival of extant trees was 52 percent for cottonwood and 77 percent for sycamore. Physical weed barriers increased survival of cottonwoods to 30 percent versus 18 percent survival with no weed control. Similarly, sycamore survival was increased from 49 percent without weed control to 64 percent with physical weed barriers. Chemical weed control adversely impacted sycamore and reduced survival to 35 percent. Tree heights did not differ between species or among weed control treatments. Girdling of trees by deer often destroyed saplings. Thus, little increase in vertical structure was detected between growing seasons. Application of fertilizer and protection via tree shelters did not improve survival or vertical development of sycamore or cottonwood.

  7. Species-driven phases and increasing structure in early-successional plant communities.

    PubMed

    Zaplata, Markus K; Winter, Susanne; Fischer, Anton; Kollmann, Johannes; Ulrich, Werner

    2013-01-01

    Successional phases describe changes in ecological communities that proceed in steps rather than continuously. Despite their importance for the understanding of ecosystem development, there still exists no reliable definition of phases and no quantitative measure of phase transitions. In order to obtain these data, we investigated primary succession in an artificial catchment (6 ha) in eastern Germany over a period of 6 years. The data set consists of records of plant species and their cover values, and initial substrate properties, both from plots in a regular grid (20 m × 20 m) suitable for spatial data analysis. Community assembly was studied by analyses of species co-occurrence and nestedness. Additionally, we correlated lognormal and log series distributions of species abundance to each community. We here introduce a new general method for detection of successional phases based on the degree of transient spatial homogeneity in the study system. Spatially coherent vegetation patterns revealed nonoverlapping partitions within this sequence of primary succession and were characterized as two distinct ecological phases. Patterns of species co-occurrence were increasingly less random, and hence the importance of demographic stochasticity and neutral community assembly decreased during the study period. Our findings highlight the spatial dimension of successional phases and quantify the degree of change between these steps. They are an element for advancing a more reliable terminology of ecological successions.

  8. Successional stage of biological soil crusts: an accurate indicator of ecohydrological condition

    USGS Publications Warehouse

    Belnap, Jayne; Wilcox, Bradford P.; Van Scoyoc, Matthew V.; Phillips, Susan L.

    2013-01-01

    Biological soil crusts are a key component of many dryland ecosystems. Following disturbance, biological soil crusts will recover in stages. Recently, a simple classification of these stages has been developed, largely on the basis of external features of the crusts, which reflects their level of development (LOD). The classification system has six LOD classes, from low (1) to high (6). To determine whether the LOD of a crust is related to its ecohydrological function, we used rainfall simulation to evaluate differences in infiltration, runoff, and erosion among crusts in the various LODs, across a range of soil depths and with different wetting pre-treatments. We found large differences between the lowest and highest LODs, with runoff and erosion being greatest from the lowest LOD. Under dry antecedent conditions, about 50% of the water applied ran off the lowest LOD plots, whereas less than 10% ran off the plots of the two highest LODs. Similarly, sediment loss was 400 g m-2 from the lowest LOD and almost zero from the higher LODs. We scaled up the results from these simulations using the Rangeland Hydrology and Erosion Model. Modelling results indicate that erosion increases dramatically as slope length and gradient increase, especially beyond the threshold values of 10 m for slope length and 10% for slope gradient. Our findings confirm that the LOD classification is a quick, easy, nondestructive, and accurate index of hydrological condition and should be incorporated in field and modelling assessments of ecosystem health.

  9. Remote sensing-based predictors improve distribution models of rare, early successional and broadleaf tree species in Utah

    USGS Publications Warehouse

    Zimmermann, N.E.; Edwards, T.C.; Moisen, G.G.; Frescino, T.S.; Blackard, J.A.

    2007-01-01

    1. Compared to bioclimatic variables, remote sensing predictors are rarely used for predictive species modelling. When used, the predictors represent typically habitat classifications or filters rather than gradual spectral, surface or biophysical properties. Consequently, the full potential of remotely sensed predictors for modelling the spatial distribution of species remains unexplored. Here we analysed the partial contributions of remotely sensed and climatic predictor sets to explain and predict the distribution of 19 tree species in Utah. We also tested how these partial contributions were related to characteristics such as successional types or species traits. 2. We developed two spatial predictor sets of remotely sensed and topo-climatic variables to explain the distribution of tree species. We used variation partitioning techniques applied to generalized linear models to explore the combined and partial predictive powers of the two predictor sets. Non-parametric tests were used to explore the relationships between the partial model contributions of both predictor sets and species characteristics. 3. More than 60% of the variation explained by the models represented contributions by one of the two partial predictor sets alone, with topo-climatic variables outperforming the remotely sensed predictors. However, the partial models derived from only remotely sensed predictors still provided high model accuracies, indicating a significant correlation between climate and remote sensing variables. The overall accuracy of the models was high, but small sample sizes had a strong effect on cross-validated accuracies for rare species. 4. Models of early successional and broadleaf species benefited significantly more from adding remotely sensed predictors than did late seral and needleleaf species. The core-satellite species types differed significantly with respect to overall model accuracies. Models of satellite and urban species, both with low prevalence, benefited

  10. [Effect of climate change on net primary productivity of Korean pine (Pinus koraiensis) at different successional stages of broad-leaved Korean pine forest].

    PubMed

    Qiu, Yang; Gao, Lu-Shuang; Zhang, Xue; Guo, Jing; Ma, Zhi-Yuan

    2014-07-01

    Pinus koraiensis in broad-leaved Korean pine forests of Changbai Mountain at different successional stages (secondary poplar-birch forest, secondary coniferous and broad-leaved forest and the primitive Korean pine forest) were selected in this paper as the research objects. In this research, the annual growth of net primary productivity (NPP) (1921-2006) of P. koraiensis was obtained by combining the tree-ring chronology and relative growth formulae, the correlation between NPP of P. koraiensis and climatic factors was developed, and the annual growth of NPP of P. koraiensis at different successional stages in relation to climatic variation within different climate periods were analyzed. The results showed that, in the research period, the correlations between climatic factors and NPP of P. koraiensis at different successional stages were different. With increasing the temperature, the correlations between NPP of P. koraiensis in the secondary poplar-birch forest and the minimum temperatures of previous and current growing seasons changed from being significantly negative to being significantly positive. The positive correlation between NPP of P. koraiensis in the secondary coniferous and broad-leaved forest and the minimum temperature in current spring changed into significantly positive correlation between NPP of P. koraiensis and the temperatures in previous and current growing seasons. The climatic factors had a stronger hysteresis effect on NPP of P. koraiensis in the secondary coniferous and broad-leaved forest, but NPP of P. koraiensis in the primitive Korean pine forest had weaker correlation with temperature but stronger positive correlation with the precipitation of previous growing season. The increases of minimum and mean temperatures were obvious, but no significant variations of the maximum temperature and precipitation were observed at our site. The climatic variation facilitated the increase of the NPP of P. koraiensis in the secondary poplar

  11. Bottom-up control of carabid beetle communities in early successional wetlands: mediated by vegetation structure or plant diversity?

    PubMed

    Brose, U

    2003-05-01

    Two hypotheses of bottom-up control that predict that the species richness of Carabidae will depend either on the taxonomic diversity of plants ("taxonomic diversity hypothesis") or on the structural heterogeneity of the vegetation ("structural heterogeneity hypothesis") were tested. Plant species were classified into nine plant structural groups through cluster analysis of morphological traits (e.g. total height) at 30 early successional temporary wetlands in the east-German agricultural landscape. In a linear regression analysis, the heterogeneity of vegetation structures explained 55% of the variation in carabid beetle diversity. According to a partial correlation analysis, plant taxonomic diversity did not have a significant effect, consistent with the "structural heterogeneity hypothesis," and contradicting previous studies which concluded that plant taxonomic diversity would be the most important factor in early successional habitats. An experimental study was used to test hypotheses on the processes underlying this bottom-up control by vegetation structure: the "hunting efficiency hypothesis," the "enemy-free space hypothesis," and the "microhabitat specialization hypothesis." The composition of plant structural groups in 15 vegetation plots (1 m(2)) was manipulated, creating a gradient from dense vegetation to open plots. Subsequent pitfall catches revealed significant differences in the activity-abundances of the carabid species. Large species preferred dense vegetation plots, consistent with the enemy-free space hypothesis that large species are more vulnerable to predation on the open plots and prefer dense vegetation to escape from natural enemies. The results indicate that bottom-up control is not mediated only by plant taxonomic or functional group diversity and that vegetation structures may be more important than previously suggested.

  12. Population structure and inbreeding vary with successional stage in created Spartina alterniflora marshes

    USGS Publications Warehouse

    Travis, S.E.; Proffitt, C.E.; Ritland, K.

    2004-01-01

    Recruitment patterns in clonal plant populations are predicted to vary with seed dispersal capability and disturbance regime, such that species with small, widely dispersed seeds will become increasingly dominated by vegetative recruitment on disturbed areas following early colonization. Subsequent mortality due to competitive or stochastic effects is then predicted to cause a gradual decline in both clonal diversity and the ability of surviving clones to avoid geitonogamous mating and possible inbreeding depression. We tested predictions of these hypotheses by comparing four adjacent populations of the salt marsh plant, Spartina alterniflora, ranging in age from 2 to ???50 yr, by measuring fine-scale genetic structure at the level of both ramets and genets, and the rate of inbreeding. For this purpose, we sampled maternal tissue and seeds from discrete patches in the field and then genotyped both maternal and seedling tissue (germinated in a growth chamber) using standard molecular protocols. As predicted, we observed an increase in clonal diversity (measured as the complement of the Simpson Index corrected for finite sample sizes, 1-D) up to a maximum of 0.71 within 3-m2 patches at 16 yr, declining to 0.55 by ???50 yr. Local recruitment of seedlings was evident as genetic structure occurring at the level of patches, as measured by the fixation index, ??, which was inversely correlated with diversity (R2 > 0.90 at all patch scales). Outcrossing rates were positively associated with clonal diversity, with the highest level (89%) at an intermediate level of 1-D. The greatest selfing (32%) occurred in young (2-yr-old) patches with low diversity. Biparental inbreeding was minimal in all populations, never exceeding 1%. Inbreeding depression was inferred to be severe, as evidenced by near-zero adult inbreeding coefficients. These results suggest a possible fitness trade-off between clonal growth and the opportunity for outcrossing. We recommend that restoration

  13. Root colonization and spore abundance of arbuscular mycorrhizal fungi in distinct successional stages from an Atlantic rainforest biome in southern Brazil.

    PubMed

    Zangaro, Waldemar; Rostirola, Leila Vergal; de Souza, Priscila Bochi; de Almeida Alves, Ricardo; Lescano, Luiz Eduardo Azevedo Marques; Rondina, Artur Berbel Lírio; Nogueira, Marco Antonio; Carrenho, Rosilaine

    2013-04-01

    The influence of plant functional groups and moderate seasonality on arbuscular mycorrhizal (AM) fungal status (root colonization and spore density) was investigated during 13 consecutive months in a chronosequence of succession in southern Brazil, consisting of grassland field, scrub vegetation, secondary forest and mature forest, in a region of transition from tropical to subtropical zones. AM root colonization and spore density decreased with advancing succession and were highest in early successional sites with grassland and scrub vegetation, intermediary in the secondary forest and lowest in the mature forest. They were little influenced by soil properties, but were sufficiently influenced by the fine root nutrient status and fine root traits among different functional plant groups. AM root colonization and spore density were higher during the favourable plant growth season (spring and summer) than during the less favourable plant growth season (autumn and winter). Spore density displayed significant seasonal variation at all sites, whilst root colonization displayed significant seasonal variation in grassland, scrub and secondary forest, but not in mature forest. The data suggest that (1) different plant functional groups display different relationships with AM fungi, influencing their abundance differentially; (2) plant species from early successional phases are more susceptible to AM root colonization and maintain higher AM sporulation than late successional species; (3) fine root traits and nutrient status influence these AM fungal attributes; and (4) higher AM spore production and root colonization is associated with the season of higher light incidence and temperature, abundant water in soil and higher plant metabolic activity.

  14. Response of Tridens flavus (L.) A. S. Hitchc. to soil nutrients and disturbance in an early successional old field

    USGS Publications Warehouse

    Honu, Y.A.K.; Gibson, D.J.; Middleton, B.A.

    2006-01-01

    Soil nutrients and disturbance are two of the main abiotic factors that influence plant dominance (canopy cover), density, and fecundity in early successional old field plant communities. The manner in which the dominant species in old field successional systems respond to the interaction of nutrients and disturbance is poorly known. We examined the dominance, density of flowering tillers, and reproductive output of Tridens flavus, a perennial, warm-season bunchgrass that is important in old field succession, to varying soil nutrient and disturbance regimes. We tested the hypothesis that the interaction between nutrients and disturbance would influence the performance (cover, density, fecundity) of T. flavus. To test this hypothesis, we subjected 25 m2 experimental plots to various combinations of fertilizer and mowing treatments for eight years after initially plowing the field. The performance of T. flavus was measured by estimating percent cover for 8 years (1996-2003) and both density of flowering tillers and reproductive output (panicle length and number of branches per panicle) for three years (2001-2003). The pattern of canopy cover of T. flavus over the first eight years of succession varied over time depending on mowing regime. Dominance was significantly higher in plots that were fertilized only in years one and five than in annually fertilized and unfertilized control plots. The length of panicles and density of flowering tillers were both significantly greater in annually mowed plots than in unmowed plots. In the absence of mowing in particular, T. flavus became overtopped by woody species and declined in this old field community. Therefore, disturbances such as mowing and fertilization may be important in maintaining grasses such as Tridens flavus in old fields.

  15. Early Life Stages

    EPA Pesticide Factsheets

    Childhood should be viewed as a sequence of lifestages, from birth through infancy and adolescence. When assessing early life risks, consideration is given to risks resulting from fetal exposure via the pregnant mother, as well as postnatal exposures.

  16. Community assembly of biological soil crusts of different successional stages in a temperate sand ecosystem, as assessed by direct determination and enrichment techniques.

    PubMed

    Langhans, Tanja Margrit; Storm, Christian; Schwabe, Angelika

    2009-08-01

    In temperate regions, biological soil crusts (BSCs: complex communities of cyanobacteria, eukaryotic algae, bryophytes, and lichens) are not well investigated regarding community structure and diversity. Furthermore, studies on succession are rare. For that reason, the community assembly of crusts representing two successional stages (initial, 5 years old; and stable, >20 years old) were analyzed in an inland sand ecosystem in Germany in a plot-based approach (2 x 18 plots, each 20 x 20 cm). Two different methods were used to record the cyanobacteria and eukaryotic algae in these communities comprehensively: determination directly out of the soil and enrichment culture techniques. Additionally, lichens, bryophytes, and phanerogams were determined. We examine four hypotheses: (1) A combination of direct determination and enrichment culture technique is necessary to detect cyanobacteria and eukaryotic algae comprehensively. In total, 45 species of cyanobacteria and eukaryotic algae were detected in the study area with both techniques, including 26 eukaryotic algae and 19 cyanobacteria species. With both determination techniques, 22 identical taxa were detected (11 eukaryotic algae and 11 cyanobacteria). Thirteen taxa were only found by direct determination, and ten taxa were only found in enrichment cultures. Hence, the hypothesis is supported. Additionally, five lichen species (three genera), five bryophyte species (five genera), and 24 vascular plant species occurred. (2) There is a clear difference between the floristic structure of initial and stable crusts. The different successional stages are clearly separated by detrended correspondence analysis, showing a distinct structure of the community assembly in each stage. In the initial crusts, Klebsormidium flaccidum, Klebsormidium cf. klebsii, and Stichococcus bacillaris were important indicator species, whereas the stable crusts are especially characterized by Tortella inclinata. (3) The biodiversity of BSC taxa

  17. Biological soil crusts reduce soil erosion in early successional subtropical forests in PR China

    NASA Astrophysics Data System (ADS)

    Seitz, Steffen; Goebes, Philipp; Käppeler, Kathrin; Nebel, Martin; Webber, Carla; Scholten, Thomas

    2016-04-01

    Biological soil crusts (BSCs) have major influences on terrestrial ecosystems and play significant functional roles in soil systems, such as accelerating soil formation, changing water flows or enhancing soil stability. By that, they have the potential to protect soil surfaces against erosive forces by wind or water. However, the effect of BSCs on erosion processes is rarely mentioned in literature and most of the work done focused on arid and semi-arid environments. Furthermore, compared to the structure and function of BSCs, less attention was paid to their temporal and topographical distribution. This study aims to investigate the influence of BSCs on initial soil erosion, and their topographical development over time in initial subtropical forest ecosystems. Therefore, measurements have been conducted within a biodiversity and ecosystem functioning experiment (BEF China) near Xingangshan, Jiangxi Province, PR China. Interrill erosion was measured on 220 microscale run-off plots (ROPs, 0.4 m × 0.4 m) and the occurrence, distribution and development of BSCs within the measuring setup were recorded. BSC cover in each ROP was determined photogrammetrically in four time steps (autumn 2011, summer 2012, summer 2013 and summer 2014). BSC species were identified by morphological characteristics and classified to higher taxonomic levels. Higher BSC cover led to reduced sediment discharge and runoff volume due to its protection against splash energy, the adherence of soil particles and enhanced infiltration. Canopy ground cover and leaf area index had a positive effect on the development of BSC cover at this initial stage of the forest ecosystem. Moreover, BSC cover decreased with increasing slope, as we presume that developing BSCs are washed away more easily at steep gradients. Elevation and aspect did not show an influence. BSCs in this study were moss-dominated and 26 different moos species were found. Mean BSC cover on ROPs was 14 % in the 3rd year of the tree

  18. The effect of local and landscape-level characteristics on the abundance of forest birds in early-successional habitats during the post-fledging season in western Massachusetts.

    PubMed

    Labbe, Michelle A; King, David I

    2014-01-01

    Many species of mature forest-nesting birds ("forest birds") undergo a pronounced shift in habitat use during the post-fledging period and move from their forest nesting sites into areas of early-successional vegetation. Mortality is high during this period, thus understanding the resource requirements of post-fledging birds has implications for conservation. Efforts to identify predictors of abundance of forest birds in patches of early-successional habitats have so far been equivocal, yet these previous studies have primarily focused on contiguously forested landscapes and the potential for landscape-scale influences in more fragmented and modified landscapes is largely unknown. Landscape composition can have a strong influence on the abundance and productivity of forest birds during the nesting period, and could therefore affect the number of forest birds in the landscape available to colonize early-successional habitats during the post-fledging period. Therefore, the inclusion of landscape characteristics should increase the explanatory power of models of forest bird abundance in early-successional habitat patches during the post-fledging period. We examined forest bird abundance and body condition in relation to landscape and habitat characteristics of 15 early-successional sites during the post-fledging season in Massachusetts. The abundance of forest birds was influenced by within-patch habitat characteristics, however the explanatory power of these models was significantly increased by the inclusion of landscape fragmentation and the abundance of forest birds in adjacent forest during the nesting period for some species and age groups. Our findings show that including factors beyond the patch scale can explain additional variation in the abundance of forest birds in early-successional habitats during the post-fledging period. We conclude that landscape composition should be considered when siting early-successional habitat to maximize its benefit to forest

  19. Predictable communities of soil bacteria in relation to nutrient concentration and successional stage in a laboratory culture experiment.

    PubMed

    Song, Woojin; Kim, Mincheol; Tripathi, Binu M; Kim, Hyoki; Adams, Jonathan M

    2016-06-01

    It is difficult to understand the processes that structure immensely complex bacterial communities in the soil environment, necessitating a simplifying experimental approach. Here, we set up a microcosm culturing experiment with soil bacteria, at a range of nutrient concentrations, and compared these over time to understand the relationship between soil bacterial community structure and time/nutrient concentration. DNA from each replicate was analysed using HiSeq2000 Illumina sequencing of the 16S rRNA gene. We found that each nutrient treatment, and each time point during the experiment, produces characteristic bacterial communities that occur predictably between replicates. It is clear that within the context of this experiment, many soil bacteria have distinct niches from one another, in terms of both nutrient concentration, and successional time point since a resource first became available. This fine niche differentiation may in part help to explain the coexistence of a diversity of bacteria in soils. In this experiment, we show that the unimodal relationship between nutrient concentration/time and species diversity often reported in communities of larger organisms is also evident in microbial communities.

  20. Comparison of throughfall chemistry in a mature hemlock forest and an early-successional deciduous forest resulting from salvage logging in Whately, Massachusetts

    NASA Astrophysics Data System (ADS)

    Zukswert, J. M.; Rhodes, A. L.; Dwyer, C. H.; Sweezy, T.

    2012-12-01

    Removal of foundation species as a result of disturbance events such as exotic species invasions can alter community composition and ecosystem function. The current hemlock woolly adelgid (Adelges tsugae) infestation in eastern North America that threatens the eastern hemlock (Tsuga canadensis), a foundation species, has motivated salvage logging efforts. Ecological succession resulting from salvage logging of hemlock would eventually produce a deciduous hardwood forest. The chemistry of throughfall beneath a mature hemlock forest canopy is expected to be more acidic than throughfall from a mature deciduous forest canopy because hemlock foliage releases more organic acids and fewer base cations. The chemical composition of throughfall during the early successional transition from hemlock to deciduous is less understood. We hypothesize that throughfall chemistry in a deciduous forest consisting primarily of juvenile trees may be more similar to direct precipitation because leaf area index is smaller. Differences between hemlock throughfall and direct precipitation may be larger due to the denser canopy of these mature trees. We compared the chemical composition of precipitation, hemlock throughfall, and black birch throughfall for 26 precipitation events from 4 March to 30 July 2012. The black birch (Betula lenta) forest patch resulted from salvage logging of hemlocks twenty years ago at the MacLeish Field Station in Whately, MA. From the three plots we measured the volume of water collected and pH, acid neutralizing capacity, dissolved organic carbon (DOC), and concentrations of cations (Ca2+, K+, Na+, Mg2+, NH4+), anions (Cl-, NO3-, SO42-), and dissolved silica. Precipitation totaled 405 mm during the course of the study. Throughfall totaled 347 mm in the black birch plot and 315 mm in the hemlock plot. The proportion of precipitation passing through the forest canopy was smaller in hemlock throughfall than black birch throughfall during small precipitation events

  1. Interactions with successional stage and nutrient status determines the life-form-specific effects of increased soil temperature on boreal forest floor vegetation

    PubMed Central

    Hedwall, Per-Ola; Skoglund, Jerry; Linder, Sune

    2015-01-01

    The boreal forest is one of the largest terrestrial biomes and plays a key role for the global carbon balance and climate. The forest floor vegetation has a strong influence on the carbon and nitrogen cycles of the forests and is sensitive to changes in temperature conditions and nutrient availability. Additionally, the effects of climate warming on forest floor vegetation have been suggested to be moderated by the tree layer. Data on the effects of soil warming on forest floor vegetation from the boreal forest are, however, very scarce. We studied the effects on the forest floor vegetation in a long-term (18 years) soil warming and fertilization experiment in a Norway spruce stand in northern Sweden. During the first 9 years, warming favored early successional species such as grasses and forbs at the expense of dwarf shrubs and bryophytes in unfertilized stands, while the effects were smaller after fertilization. Hence, warming led to significant changes in species composition and an increase in species richness in the open canopy nutrient limited forest. After another 9 years of warming and increasing tree canopy closure, most of the initial effects had ceased, indicating an interaction between forest succession and warming. The only remaining effect of warming was on the abundance of bryophytes, which contrary to the initial phase was strongly favored by warming. We propose that the suggested moderating effects of the tree layer are specific to plant life-form and conclude that the successional phase of the forest may have a considerable impact on the effects of climate change on forest floor vegetation and its feedback effects on the carbon and nitrogen cycles, and thus on the climate. PMID:25750720

  2. Pigment patterns and photoprotection of anthocyanins in the young leaves of four dominant subtropical forest tree species in two successional stages under contrasting light conditions.

    PubMed

    Zhu, H; Zhang, T J; Zhang, P; Peng, C L

    2016-09-01

    Light-driven subtropical forest succession is a dynamic process in which mesophytic climax communities replace heliophytic ones. Juvenile leaves (particularly mesophytic ones) are sensitive to high irradiances. To determine the photoprotection strategy that juvenile leaves use during subtropical forest succession, anthocyanin accumulation patterns were investigated in the young leaves of two mid-successional dominant trees (i.e., Schima superba and Castanopsis fissa) and two late-successional dominant trees (i.e., Cryptocarya concinna and Acmena acuminatissima) grown in 100% (FL) and 25% (LL) of full sunlight. All four tree species produced anthocyanins in their juvenile leaves when <50% of chlorophylls and carotenoids had developed. Higher anthocyanin concentrations accumulated in the young leaves grown in FL than in those grown in LL and in late-successional than in mid-successional trees. The juvenile leaves of late-successional trees were subjected to higher light-induced photoinhibition than those of mid-successional trees, despite of the fact that the leaves of late-successional trees showed greater non-photochemical quenching than those of mid-successional trees. Under LL conditions, photosystem II excitation pressure (1 - qP) was significantly higher in the juvenile leaves of late-successional trees than those of mid-successional trees. Under either FL or LL conditions, anthocyanin concentrations in juvenile leaves were negatively related to the light compensation point in mature leaves across species. However, anthocyanin concentrations were positively related to the antioxidant capacity of juvenile leaves. These results indicate that anthocyanin accumulation in the juvenile leaves of subtropical dominant trees during forest community succession is a flexible photoprotective response to ambient irradiances according to leaf sensitivity to light.

  3. Soil fungal community development in a high Arctic glacier foreland follows a directional replacement model, with a mid-successional diversity maximum

    PubMed Central

    Dong, Ke; Tripathi, Binu; Moroenyane, Itumeleng; Kim, Woosung; Li, Nan; Chu, Haiyan; Adams, Jonathan

    2016-01-01

    Directional replacement and directional non-replacement models are two alternative paradigms for community development in primary successional environments. The first model emphasizes turnover in species between early and late successional niches. The second emphasizes accumulation of additional diversity over time. To test whether the development of soil fungal communities in the foreland of an Arctic glacier conforms to either of these models, we collected samples from the Midtre Lovénbreen Glacier, Svalbard, along a soil successional series spanning >80 years. Soil DNA was extracted, and fungal ITS1 region was amplified and sequenced on an Illumina Miseq. There was a progressive change in community composition in the soil fungal community, with greatest fungal OTU richness in the Mid Stage (50–80 years). A nestedness analysis showed that the Early Stage (20–50 years) and the Late Stage (>80 years) fungal communities were nested within the Mid Stage communities. These results imply that fungal community development in this glacier succession follows a directional replacement model. Soil development processes may initially be important in facilitating arrival of additional fungal species, to give a mid-successional diversity maximum that contains both early- and late-successional fungi. Competition may then decrease the overall diversity due to the loss of early successional species. PMID:27240660

  4. Biological significance of dead biomass retention trait in Mediterranean Basin species: an analysis between different successional niches and regeneration strategies as functional groups.

    PubMed

    Baeza, M J; Santana, V M

    2015-11-01

    Standing dead biomass retention is considered one of the most relevant fuel structural traits to affect plant flammability. However, very little is known about the biological significance of this trait and its distribution between different functional groups. Our aim was to analyse how the proportion of dead biomass produced in Mediterranean species is related to the successional niche of species (early-, mid- and late-successional stages) and the regeneration strategy of species (seeders and resprouters). We evaluated biomass distribution by size classes and standing dead biomass retention in nine dominant species from the Mediterranean Basin in different development stages (5, 9, 14 and 26 years since the last fire). The results revealed significant differences in the standing dead biomass retention of species that presented a distinct successional niche or regeneration strategy. These differences were restricted to the oldest ages studied (>9 years). Tree and small tree resprouters, typical in late-successional stages, presented slight variations with age and a less marked trend to retain dead biomass, while seeder shrubs and dwarf shrubs, characteristic of early-successional stages, showed high dead biomass loads. Our results suggest that the species that tend to retain more dead branches are colonising species that may promote fire in early-successional stages.

  5. Structural and functional changes in early successional stages of a semiarid ecosystem

    SciTech Connect

    Redente, E.F.; Cook, C.W.

    1986-02-01

    The objective of our research was to study structural and functional changes that occur within and between ecosystem compartments during secondary succession in disturbed semiarid environments. First year data clearly showed an increase in resource abundance after disturbance which produced not only alteration of the soil surface but a decrease in available organic matter. In addition, marked increases in NO3 and soil water potentials were evident at all depths in the disturbed sites as compared to the undisturbed community. Soil disturbance as well as manipulation of the microflora compartment by fumigation had a significant impact on microflora structure and function. The mycorrhizal population was also drastically reduced by disturbance and fumigation. The floristic composition of the primary producers on the disturbed site was highly correlated with the propagule supply, with composition of the seed bank being the main driving force. Competition studies between bluebunch wheatgrass (Agropyron inerme), western wheatgrass, big sagebrush (Artemisia tridentata), and winterfat (Ceratoides lanata) showed that these four species were able to coexist under a wide range of water availability conditions. The final phase of an experiment designed to determine the effects of retorted shale recarbonation on plant uptake of toxic trace elements was completed. These initial studies indicate that both plant community characteristics and the presence of a functioning belowground community will be important in secondary succession processes which occur in disturbed semiarid environments. 36 figs., 41 tabs.

  6. Ectomycorrhizas in vitro between Tricholoma matsutake, a basidiomycete that associates with Pinaceae, and Betula platyphylla var. japonica, an early-successional birch species, in cool-temperate forests.

    PubMed

    Murata, Hitoshi; Yamada, Akiyoshi; Maruyama, Tsuyoshi; Neda, Hitoshi

    2015-04-01

    Tricholoma matsutake is an ectomycorrhizal basidiomycete that associates with Pinaceae in the Northern Hemisphere and produces prized "matsutake" mushrooms. We questioned whether the symbiont could associate with a birch that is an early-successional species in boreal, cool-temperate, or subalpine forests. In the present study, we demonstrated that T. matsutake can form typical ectomycorrhizas with Betula platyphylla var. japonica; the associations included a Hartig net and a thin but distinct fungal sheath, as well as the rhizospheric mycelial aggregate "shiro" that is required for fruiting in nature. The in vitro shiro also emitted a characteristic aroma. This is the first report of an ectomycorrhizal formation between T. matsutake and a deciduous broad-leaved tree in the boreal or cool-temperate zones that T. matsutake naturally inhabits.

  7. The Effect of Local and Landscape-Level Characteristics on the Abundance of Forest Birds in Early-Successional Habitats during the Post-Fledging Season in Western Massachusetts

    PubMed Central

    Labbe, Michelle A.; King, David I.

    2014-01-01

    Many species of mature forest-nesting birds (“forest birds”) undergo a pronounced shift in habitat use during the post-fledging period and move from their forest nesting sites into areas of early-successional vegetation. Mortality is high during this period, thus understanding the resource requirements of post-fledging birds has implications for conservation. Efforts to identify predictors of abundance of forest birds in patches of early-successional habitats have so far been equivocal, yet these previous studies have primarily focused on contiguously forested landscapes and the potential for landscape-scale influences in more fragmented and modified landscapes is largely unknown. Landscape composition can have a strong influence on the abundance and productivity of forest birds during the nesting period, and could therefore affect the number of forest birds in the landscape available to colonize early-successional habitats during the post-fledging period. Therefore, the inclusion of landscape characteristics should increase the explanatory power of models of forest bird abundance in early-successional habitat patches during the post-fledging period. We examined forest bird abundance and body condition in relation to landscape and habitat characteristics of 15 early-successional sites during the post-fledging season in Massachusetts. The abundance of forest birds was influenced by within-patch habitat characteristics, however the explanatory power of these models was significantly increased by the inclusion of landscape fragmentation and the abundance of forest birds in adjacent forest during the nesting period for some species and age groups. Our findings show that including factors beyond the patch scale can explain additional variation in the abundance of forest birds in early-successional habitats during the post-fledging period. We conclude that landscape composition should be considered when siting early-successional habitat to maximize its benefit to

  8. Do natural disturbances or the forestry practices that follow them convert forests to early-successional communities?

    PubMed

    Brewer, J Stephen; Bertz, Christine A; Cannon, Jeffery B; Chesser, Jason D; Maynard, Erynn E

    2012-03-01

    Stand-replacing natural disturbances in mature forests are traditionally seen as events that cause forests to revert to early stages of succession and maintain species diversity. In some cases, however, such transitions could be an artifact of salvage logging and may increase biotic homogenization. We present initial (two-year) results of a study of the effects of tornado damage and the combined effects of tornado damage and salvage logging on environmental conditions and ground cover plant communities in mixed oak-pine forests in north central Mississippi. Plots were established in salvage-logged areas, adjacent to plots established before the storm in unlogged areas, spanning a gradient of storm damage intensity. Vegetation change directly attributable to tornado damage was driven primarily by a reduction in canopy cover but was not consistent with a transition to an early stage of succession. Although we observed post-storm increases of several disturbance indicators (ruderals), we also observed significant increases in the abundance of a few species indicative of upland forests. Increases in flowering were just as likely to occur in species indicative of forests as in species indicative of open woodlands. Few species declined as a result of the tornado, resulting in a net increase in species richness. Ruderals were very abundant in salvage-logged areas, which contained significantly higher amounts of bare ground and greater variance in soil penetrability than did damaged areas that were not logged. In contrast to unlogged areas severely damaged by the tornado, most upland forest indicators were not abundant in logged areas. Several of the forest and open-woodland indicators that showed increased flowering in damaged areas were absent or sparse in logged areas. Species richness was lower in salvage-logged areas than in adjacent damaged areas but similar to that in undamaged areas. These results suggest that salvage logging prevented positive responses of several

  9. Dislocation generation during early stage sintering.

    NASA Technical Reports Server (NTRS)

    Sheehan, J. E.; Lenel, F. V.; Ansell, G. S.

    1973-01-01

    Discussion of the effects of capillarity-induced stresses on dislocations during early stage sintering. A special version of Hirth's (1963) theoretical calculation procedures modified to describe dislocation nucleation on planes meeting the sintering body's neck surface obliquely is shown to predict plastic flow at stress levels know to exist between micron size metal particles in the early stages of sintering.

  10. The Early Stages of Interlanguage.

    ERIC Educational Resources Information Center

    Schumann, John

    The stages of interlanguage, the speech of beginning second language learners as they progress toward second language fluency, are described. Examples are drawn from the speech of Spanish speaking students of English as a second language. The continuum of interlanguage development from native language forms to target language forms includes three…

  11. Short-Term responses of breeding birds of grassland and early successional habitat to timing of haying in Northwestern Arkansas

    USGS Publications Warehouse

    Luscier, J.D.; Thompson, W.L.

    2009-01-01

    In 2003, we evaluated nest survival and density of the Dickcissel (Spiza americana), Eastern Meadowlark (Sturnella magna), Field Sparrow (Spizella pusilla), and Red-winged Blackbird (Agelaius phoeniceus) in four unhayed, two early-hayed (26-31 May) and three late-hayed (17-25 June) fields in northwestern Arkansas. Rope dragging and observations revealed 89 nests. Daily nest-survival rates (SE) prior to haying ranged from 0.94 (0.03) to 0.97 (0.02). Early haying affected both nest-survival rates and bird densities negatively, whereas late haying had minimal effects. Fifteen nests in hayed portions of early-hayed fields were destroyed, whereas only 2 of 52 nests were affected by late haying. Density was at least 0.98 birds ha-1 higher in unhayed than in early-hayed fields and 1.03 birds ha-1 higher in late-hayed than in early-hayed fields. In northwestern Arkansas, postponing haying until mid- to late June would allow time for nestlings to fledge, would have little effect on bird densities, and would affect hay nutrition and regrowth minimally. ?? The Cooper Ornithological Society, 2009.

  12. Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

    USGS Publications Warehouse

    Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, J.; Zhou, C.-Y.

    2006-01-01

    The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

  13. Liquid biopsy in early stage lung cancer

    PubMed Central

    Pérez-Ramírez, Cristina; Robles, Ana I.; Molina, Miguel Ángel; Faus-Dáder, María José; Calleja-Hernández, Miguel Ángel

    2016-01-01

    Lung cancer is the leading cause of cancer-associated deaths worldwide. Surgery is the standard treatment for early-stage non-small cell lung cancer (NSCLC). However, 30% to 80% of these patients will die within 5 yearS of diagnosis. Circulating cell-free DNA (cfDNA) harbors pathologic characteristics of the original tumor, such as gene mutations or epigenetic alterations. Analysis of cfDNA has revolutionized the clinical care of advanced lung cancer patients undergoing targeted therapies. However, the low concentration of cfDNA in the blood of early-stage NSCLC patients has hampered its use for management of early disease. Continuing development of more specific and sensitive techniques for detection and analysis of cfDNA will soon enable its leverage in early stage and, perhaps, even screening settings. Therefore, cfDNA analysis may become a tool used for routine NSCLC diagnosis and for monitoring tumor burden, as well as for identifying hidden residual disease. In this review, we will focus on the current evidence of cfDNA in patients with early-stage NSCLC, new and upcoming approaches to identify circulating-tumor biomarkers, their clinical applications and future directions. PMID:27826533

  14. Treatment of early stage vocal cord carcinoma

    SciTech Connect

    Ayers, G.

    1989-03-01

    The cure rates for early stage vocal cord cancer are excellent with primary radiotherapy. Voice quality remains as good or becomes better than prior to treatment. For the local failures that do occur, surgical salvage will yield ultimate cure rates of about 95% for T1 and 90% for T2 tumors.

  15. Suicide in the Early Stage of Schizophrenia.

    PubMed

    Ventriglio, Antonio; Gentile, Alessandro; Bonfitto, Iris; Stella, Eleonora; Mari, Massimo; Steardo, Luca; Bellomo, Antonello

    2016-01-01

    Suicide is a relevant leading cause of death among patients affected by schizophrenia. Even if suicidal ideation may be present in different stages of disease, some differences have been described between the risk of suicide in patients experiencing first episode of psychosis and those with long-term schizophrenia. It is particularly higher during the first year of illness and reaches a steady decline over the following years. Suicidal ideation and attempts may also be common among subjects with subthreshold psychotic experiences. Factors associated with the risk of suicide in the early phase of schizophrenia are previous suicidal attempts and social aspects: the lack of social support and stable relationships, social drift after the first episode, and social impairment. Also, several psychotic symptoms (suspiciousness, paranoid delusions, mental disintegration and agitation, negative symptoms, depression and hopelessness, and command hallucinations) and substance abuse are associated with higher risk of suicide. It has been described that perfectionism and good levels of insight among individuals who have recently developed psychotic symptoms are significantly associated with higher numbers of suicidal attempts. Moreover, recent evidences show that prefrontal cortex-based circuit dysfunction may be related to suicide in the early stage of schizophrenia. This narrative review summarizes available evidences on suicide in the early stage of schizophrenia and deals with issues to be further studied and discussed.

  16. Suicide in the Early Stage of Schizophrenia

    PubMed Central

    Ventriglio, Antonio; Gentile, Alessandro; Bonfitto, Iris; Stella, Eleonora; Mari, Massimo; Steardo, Luca; Bellomo, Antonello

    2016-01-01

    Suicide is a relevant leading cause of death among patients affected by schizophrenia. Even if suicidal ideation may be present in different stages of disease, some differences have been described between the risk of suicide in patients experiencing first episode of psychosis and those with long-term schizophrenia. It is particularly higher during the first year of illness and reaches a steady decline over the following years. Suicidal ideation and attempts may also be common among subjects with subthreshold psychotic experiences. Factors associated with the risk of suicide in the early phase of schizophrenia are previous suicidal attempts and social aspects: the lack of social support and stable relationships, social drift after the first episode, and social impairment. Also, several psychotic symptoms (suspiciousness, paranoid delusions, mental disintegration and agitation, negative symptoms, depression and hopelessness, and command hallucinations) and substance abuse are associated with higher risk of suicide. It has been described that perfectionism and good levels of insight among individuals who have recently developed psychotic symptoms are significantly associated with higher numbers of suicidal attempts. Moreover, recent evidences show that prefrontal cortex-based circuit dysfunction may be related to suicide in the early stage of schizophrenia. This narrative review summarizes available evidences on suicide in the early stage of schizophrenia and deals with issues to be further studied and discussed. PMID:27445872

  17. Successional dynamics in the seasonally forced diamond food web.

    PubMed

    Klausmeier, Christopher A; Litchman, Elena

    2012-07-01

    Plankton seasonal succession is a classic example of nonequilibrium community dynamics. Despite the fact that it has been well studied empirically, it lacks a general quantitative theory. Here we investigate a food web model that includes a resource, two phytoplankton, and a shared grazer-the diamond food web-in a seasonal environment. The model produces a number of successional trajectories that have been widely discussed in the context of the verbal Plankton Ecology Group model of succession, such as a spring bloom of a good competitor followed by a grazer-induced clear-water phase, setting the stage for the late-season dominance of a grazer-resistant species. It also predicts a novel, counterintuitive trajectory where the grazer-resistant species has both early- and late-season blooms. The model often generates regular annual cycles but sometimes produces multiyear cycles or chaos, even with identical forcing each year. Parameterizing the model, we show how the successional trajectory depends on nutrient supply and the length of the growing season, two key parameters that vary among water bodies. This model extends nonequilibrium theory to food webs and is a first step toward a quantitative theory of plankton seasonal succession.

  18. Spatial variation in fish assemblages across a beaver-influenced successional landscape

    USGS Publications Warehouse

    Schlosser, I.J.; Kallemeyn, L.W.

    2000-01-01

    Beavers are increasingly viewed as 'ecological engineers,' having broad effects on physical, chemical, and biological attributes of north-temperate landscapes. We examine the influence of both local successional processes associated with beaver activity and regional geomorphic boundaries on spatial variation in fish assemblages along the Kabetogama Peninsula in Voyageurs National Park, northern Minnesota, USA. Fish abundance and species richness exhibited considerable variation among drainages along the peninsula. Geological barriers to fish dispersal at outlets of some drainages has reduced fish abundance and species richness. Fish abundance and species richness also varied within drainages among local environments associated with beaver pond succession. Fish abundance was higher in upland ponds than in lowland ponds, collapsed ponds, or streams, whereas species richness was highest in collapsed ponds and streams. Cluster analyses based on fish abundance at sites classified according to successional environment indicated that four species (northern redbelly dace, Phoxinus eos; brook stickleback, Culaea inconstans; finescale dace, P. neogaeus; and fathead minnow, Pimephales promelas), were predominant in all successional environments. Several less abundant species were added in collapsed ponds and streams, with smaller size classes of large lake species (e.g., black crappie, Pomoxis nigromaculatus; smallmouth bass, Micropertus dolomieui; yellow perch, Perca flavescens; and burbot, Lota lota) being a component of these less abundant species. The addition of smaller size classes of large lake species indicates that dispersal of early life-history stages from Kabetogama Lake played a role in determining the species richness and composition of less abundant species in successional environments on the peninsula. Furthermore, collapsed-pond and stream environments closer to Kabetogama Lake had higher species richness than similar successional sites located farther from

  19. Is the degree of clonality of forest herbs dependent on gap age? Using fingerprinting approaches to assess optimum successional stages for montane forest herbs

    PubMed Central

    Patsias, Kathrin; Bruelheide, Helge

    2011-01-01

    Using molecular fingerprinting (amplified fragment length polymorphism [AFLP] method), we explored the potential of small-scale population analysis for understanding colonization patterns of herb layer species in forests after canopy disturbance. We investigated three common forest understorey species with different life forms (Trientalis europaea, Calamagrostis villosa, and Vaccinium myrtillus) in the Harz Mountains in Germany in three different gap age classes and undisturbed forest. For two of them (T. europaea and C. villosa), we analyzed clone sizes and clonal structure. We hypothesized that clone sizes depend on age since gap formation and are affected by light availability. Mean patch sizes of V. myrtillus, T. europaea, and C. villosa formed were 3.7 m2, 27.9 m2, and 40.6 m2, respectively. Trientalis europaea and C. villosa patches consisted mostly of more than one genet. Largest clone sizes of T. europaea were encountered in gaps of intermediate successional age (15–60 years, averaged minimum estimation of clone sizes: 6.56 m2) whereas clone size of C. villosa was found to be independent from gap age and had a mean minimum clone size of 0.49 m2. In both species, clone size was positively related to light availability. Additionally, there was a positive relationship between clone size and ramet density for T. europaea and C. villosa. Genetic variation was higher within populations of T. europaea and C. villosa than among populations. Trientalis europaea was the only species with a clear genetic isolation by distance, pointing at an equilibrium between gene flow and genetic drift. In conclusion, we showed that forest canopy gap dynamics clearly affect the small-scale structure of populations of understorey plants. Species with high lateral growth rates, such as T. europaea offer the possibility to serve as “ecological clock” for dating ecological processes. PMID:22393501

  20. Responses to nitrogen pulses and growth under low nitrogen availability in invasive and native tree species with differing successional status.

    PubMed

    Osone, Yoko; Yazaki, Kenichi; Masaki, Takeshi; Ishida, Atsushi

    2014-03-01

    Invasive species are frequently found in recently disturbed sites. To examine how these disturbance-dependent invasive species exploit resource pulses resulting from disturbance, twelve physiological and morphological traits, including age-dependent responsiveness in leaf traits to nitrogen pulse, were compared between Bischofia javanica, an invasive tree species in Ogasawara islands, and three native Ogasawara species, each having a different successional status. When exposed to a nitrogen pulse, invasive B. javanica showed higher increases in photosynthetic capacity, leaf area, epidermal cell number and cell size in leaves of broad age classes, and root nitrogen absorption ability than two native mid-/late or late-successional species, but showed no particular superiority to a native pioneer species in these responses. Under low nitrogen, however, it showed the largest relative growth rate among the four species, while the native pioneer showed the lowest growth. From these results, we concluded that the combination of moderately high responsiveness to resource pulses and the ability to maintain steady growth under resource limitations may give B. javanica a competitive advantage over a series of native species with different successional status from early to late-successional stages.

  1. Exploiting water versus tolerating drought: water-use strategies of trees in a secondary successional tropical dry forest.

    PubMed

    Pineda-García, Fernando; Paz, Horacio; Meinzer, Frederick C; Angeles, Guillermo

    2016-02-01

    In seasonal plant communities where water availability changes dramatically both between and within seasons, understanding the mechanisms that enable plants to exploit water pulses and to survive drought periods is crucial. By measuring rates of physiological processes, we examined the trade-off between water exploitation and drought tolerance among seedlings of trees of a tropical dry forest, and identified biophysical traits most closely associated with plant water-use strategies. We also explored whether early and late secondary successional species occupy different portions of trade-off axes. As predicted, species that maintained carbon capture, hydraulic function and leaf area at higher plant water deficits during drought had low photosynthetic rates, xylem hydraulic conductivity and growth rate under non-limiting water supply. Drought tolerance was associated with more dense leaf, stem and root tissues, whereas rapid resource acquisition was associated with greater stem water storage, larger vessel diameter and larger leaf area per mass invested. We offer evidence that the water exploitation versus drought tolerance trade-off drives species differentiation in the ability of tropical dry forest trees to deal with alternating water-drought pulses. However, we detected no evidence of strong functional differentiation between early and late successional species along the proposed trade-off axes, suggesting that the environmental gradient of water availability across secondary successional habitats in the dry tropics does not filter out physiological strategies of water use among species, at least at the seedling stage.

  2. Successional changes of Collembola and soil microbiota during forest rotation.

    PubMed

    Chauvat, Matthieu; Zaitsev, Andrei S; Wolters, Volkmar

    2003-10-01

    Dynamic approaches to forest ecosystems are surprisingly rare. Here we report about successional changes in collembolan community structure and microbial performances during forest rotation. The study was carried out in a chronosequence of four spruce forest stands (5-, 25-, 45-, and 95 years old; Tharandter forest, Germany). CO2 release significantly increased after clear-cutting and the amount of C stored in the organic layer subsequently declined. The early phase of forest rotation was characterized by a very active decomposer microflora, stimulation of both fungi and bacteria as well as by a high abundance of surface-oriented Collembola. In addition, collembolan species turnover was accelerated. While the biomass of fungi further increased at intermediate stages of forest rotation, the metabolic activity of the microflora was low, the functional diversity of bacteria declined and the collembolan community became impoverished. Euedaphic species dominated during this stage of forest development. These changes can be explained by both reduction in microhabitat diversity and depletion of food sources associated with an accumulation of recalcitrant soil organic matter. Results of the General Regression Model procedure indicate a shift from specific associations between collembolan functional groups and microbiota at the early stage of forest rotation to a more diffuse pattern at intermediate stages. Though the hypothesis that Collembola are relatively responsive to changes in environmental conditions is confirmed, consistently high community similarity suggests a remarkable persistence of some components of microarthropod assemblages. Our study provides evidence for substantial ecosystem-level implications of changes in the soil food web during forest rotation. Moreover, correlations between bacterial parameters and Collembola point to the overarching impact of differences in the composition of the microbial community on microarthropods.

  3. An actuarial approach to comparing early stage and late stage lung cancer mortality and survival.

    PubMed

    Goldberg, Sara W; Mulshine, James L; Hagstrom, Dale; Pyenson, Bruce S

    2010-02-01

    Comparing the mortality characteristics of different cohorts is an essential process in the life insurance industry. Pseudodisease, lead-time bias, and length bias, which are critical to determining the value of cancer screening, have close analogues in life insurance company management, including the temporal impact of underwriting. Ratios of all-cause mortality rates for cancer cohorts relative to standard population mortality rates can provide insights into early stage and late stage mortality differences, differences by age, sex, race, and histology, and allow modeling of biases associated with early stage detection or screening protocols. The Surveillance, Epidemiology and End Results (SEER) data set has characteristics that allow efficient application of actuarial techniques. We show the mortality burden associated with treated early stage lung cancer and that identifying all lung cancers at early stage could reduce US lung cancer deaths by over 70,000 per year.

  4. Critical pneumonia complicating early-stage pregnancy.

    PubMed

    Mercieri, Marco; Di Rosa, Roberta; Pantosti, Annalisa; De Blasi, Roberto Alberto; Pinto, Giovanni; Arcioni, Roberto

    2010-03-01

    We present a case of community-acquired methicillin-resistant Staphylococcus aureus necrotizing pneumonia, Panton-Valentine leukocidin positive, in a woman at 14 weeks of pregnancy. To our knowledge, this is the first case reporting this critical lung infection occurring during an early phase of pregnancy. This case study alerts physicians to the increasing worldwide spread of these uncommon yet virulent and potentially lethal infections. In our patient, antibiotic therapy with linezolid plus rifampin started at 14 weeks of pregnancy had a successful outcome without inducing toxicity or teratogenesis in the fetus.

  5. Spatial and successional dynamics of microbial biofilm communities in a grassland stream ecosystem.

    PubMed

    Veach, Allison M; Stegen, James C; Brown, Shawn P; Dodds, Walter K; Jumpponen, Ari

    2016-09-01

    Biofilms represent a metabolically active and structurally complex component of freshwater ecosystems. Ephemeral prairie streams are hydrologically harsh and prone to frequent perturbation. Elucidating both functional and structural community changes over time within prairie streams provides a general understanding of microbial responses to environmental disturbance. We examined microbial succession of biofilm communities at three sites in a third-order stream at Konza Prairie over a 2- to 64-day period. Microbial abundance (bacterial abundance, chlorophyll a concentrations) increased and never plateaued during the experiment. Net primary productivity (net balance of oxygen consumption and production) of the developing biofilms did not differ statistically from zero until 64 days suggesting a balance of the use of autochthonous and allochthonous energy sources until late succession. Bacterial communities (MiSeq analyses of the V4 region of 16S rRNA) established quickly. Bacterial richness, diversity and evenness were high after 2 days and increased over time. Several dominant bacterial phyla (Beta-, Alphaproteobacteria, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Chloroflexi) and genera (Luteolibacter, Flavobacterium, Gemmatimonas, Hydrogenophaga) differed in relative abundance over space and time. Bacterial community composition differed across both space and successional time. Pairwise comparisons of phylogenetic turnover in bacterial community composition indicated that early-stage succession (≤16 days) was driven by stochastic processes, whereas later stages were driven by deterministic selection regardless of site. Our data suggest that microbial biofilms predictably develop both functionally and structurally indicating distinct successional trajectories of bacterial communities in this ecosystem.

  6. Spatial and successional dynamics of microbial biofilm communities in a grassland stream ecosystem

    SciTech Connect

    Veach, Allison M.; Stegen, James C.; Brown, Shawn P.; Dodds, Walter K.; Jumpponen, Ari

    2016-09-06

    Biofilms represent a metabolically active and structurally complex component of freshwater ecosystems. Ephemeral prairie streams are hydrologically harsh and prone to frequent perturbation. Elucidating both functional and structural community changes over time within prairie streams provides a general understanding of microbial responses to environmental disturbance. In this study, we examined microbial succession of biofilm communities at three sites in a third-order stream at Konza Prairie over a 2- to 64-day period. Microbial abundance (bacterial abundance, chlorophyll a concentrations) increased and never plateaued during the experiment. Net primary productivity (net balance of oxygen consumption and production) of the developing biofilms did not differ statistically from zero until 64 days suggesting a balance of the use of autochthonous and allochthonous energy sources until late succession. Bacterial communities (MiSeq analyses of the V4 region of 16S rRNA) established quickly. Bacterial richness, diversity and evenness were high after 2 days and increased over time. Several dominant bacterial phyla (Beta-, Alphaproteobacteria, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Chloroflexi) and genera (Luteolibacter, Flavobacterium, Gemmatimonas, Hydrogenophaga) differed in relative abundance over space and time. Bacterial community composition differed across both space and successional time. Pairwise comparisons of phylogenetic turnover in bacterial community composition indicated that early-stage succession (≤16 days) was driven by stochastic processes, whereas later stages were driven by deterministic selection regardless of site. Finally, our data suggest that microbial biofilms predictably develop both functionally and structurally indicating distinct successional trajectories of bacterial communities in this ecosystem.

  7. Effects of ENSO and temporal rainfall variation on the dynamics of successional communities in old-field succession of a tropical dry forest.

    PubMed

    Maza-Villalobos, Susana; Poorter, Lourens; Martínez-Ramos, Miguel

    2013-01-01

    The effects of temporal variation of rainfall on secondary succession of tropical dry ecosystems are poorly understood. We studied effects of inter-seasonal and inter-year rainfall variation on the dynamics of regenerative successional communities of a tropical dry forest in Mexico. We emphasized the effects caused by the severe El Niño Southern Oscillation (ENSO) occurred in 2005. We established permanent plots in sites representing a chronosequence of Pasture (abandoned pastures, 0-1 years fallow age), Early (3-5), Intermediate (8-12), and Old-Growth Forest categories (n = 3 per category). In total, 8210 shrubs and trees 10 to 100-cm height were identified, measured, and monitored over four years. Rates of plant recruitment, growth and mortality, and gain and loss of species were quantified per season (dry vs. rainy), year, and successional category, considering whole communities and separating seedlings from sprouts and shrubs from trees. Community rates changed with rainfall variation without almost any effect of successional stage. Mortality and species loss rates peaked during the ENSO year and the following year; however, after two rainy years mortality peaked in the rainy season. Such changes could result from the severe drought in the ENSO year, and of the outbreak of biotic agents during the following rainy years. Growth, recruitment and species gain rates were higher in the rainy season but they were significantly reduced after the ENSO year. Seedlings exhibited higher recruitment and mortality rate than sprouts, and shrubs showed higher recruitment than trees. ENSO strongly impacted both the dynamics and trajectory of succession, creating transient fluctuations in the abundance and species richness of the communities. Overall, there was a net decline in plant and species density in most successional stages along the years. Therefore, strong drought events have critical consequences for regeneration dynamics, delaying the successional process and

  8. Effects of ENSO and Temporal Rainfall Variation on the Dynamics of Successional Communities in Old-Field Succession of a Tropical Dry Forest

    PubMed Central

    Maza-Villalobos, Susana; Poorter, Lourens; Martínez-Ramos, Miguel

    2013-01-01

    The effects of temporal variation of rainfall on secondary succession of tropical dry ecosystems are poorly understood. We studied effects of inter-seasonal and inter-year rainfall variation on the dynamics of regenerative successional communities of a tropical dry forest in Mexico. We emphasized the effects caused by the severe El Niño Southern Oscillation (ENSO) occurred in 2005. We established permanent plots in sites representing a chronosequence of Pasture (abandoned pastures, 0–1 years fallow age), Early (3–5), Intermediate (8–12), and Old-Growth Forest categories (n = 3 per category). In total, 8210 shrubs and trees 10 to 100-cm height were identified, measured, and monitored over four years. Rates of plant recruitment, growth and mortality, and gain and loss of species were quantified per season (dry vs. rainy), year, and successional category, considering whole communities and separating seedlings from sprouts and shrubs from trees. Community rates changed with rainfall variation without almost any effect of successional stage. Mortality and species loss rates peaked during the ENSO year and the following year; however, after two rainy years mortality peaked in the rainy season. Such changes could result from the severe drought in the ENSO year, and of the outbreak of biotic agents during the following rainy years. Growth, recruitment and species gain rates were higher in the rainy season but they were significantly reduced after the ENSO year. Seedlings exhibited higher recruitment and mortality rate than sprouts, and shrubs showed higher recruitment than trees. ENSO strongly impacted both the dynamics and trajectory of succession, creating transient fluctuations in the abundance and species richness of the communities. Overall, there was a net decline in plant and species density in most successional stages along the years. Therefore, strong drought events have critical consequences for regeneration dynamics, delaying the successional process

  9. Management of Early-stage Hodgkin Lymphoma: A Practice Guideline.

    PubMed

    Herst, J; Crump, M; Baldassarre, F G; MacEachern, J; Sussman, J; Hodgson, D; Cheung, M C

    2017-01-01

    In the past, treatment for patients with early-stage Hodgkin lymphoma consisted mainly of radiotherapy. Now, chemotherapy alone and chemoradiotherapy are treatment options. These guidelines aim to provide recommendations on the optimal management of early-stage Hodgkin lymphoma. We conducted a systematic review searching MEDLINE, EMBASE, the Cochrane Library and other literature sources from 2003 to 2015, and applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Two authors independently reviewed and selected studies, and appraised the evidence quality. The document underwent internal and external review by content, methodology experts, a patient representative and clinicians in Ontario. We have issued recommendations for patients with classical Hodgkin lymphoma and with nodular lymphocyte predominant Hodgkin lymphoma; with favourable and unfavourable prognosis; and for the use of positron emission tomography to direct treatment. We have provided our interpretation of the evidence and considerations for implementation. Examples of recommendations are: 'Patients with early-stage classical Hodgkin lymphoma should not be treated with radiotherapy alone'; 'chemotherapy plus radiotherapy or chemotherapy alone are recommended treatment options for patients with early-stage non-bulky Hodgkin lymphoma'; 'The Working Group does not recommend the use of a negative interim positron emission tomography scan alone to identify patients with early-stage Hodgkin lymphoma for whom radiotherapy can be omitted without a reduction in progression-free survival'. Through the use of GRADE, recommendations were geared towards patient important outcomes and their strength reflected the available evidence and its interpretation from the patients' point of view.

  10. Unraveling Mixed Hydrate Formation: Microscopic Insights into Early Stage Behavior.

    PubMed

    Hall, Kyle Wm; Zhang, Zhengcai; Kusalik, Peter G

    2016-12-29

    The molecular-level details of mixed hydrate nucleation remain unclear despite the broad implications of this process for a variety of scientific domains. Through analysis of mixed hydrate nucleation in a prototypical CH4/H2S/H2O system, we demonstrate that high-level kinetic similarities between mixed hydrate systems and corresponding pure hydrate systems are not a reliable basis for estimating the composition of early stage mixed hydrate nuclei. Moreover, we show that solution compositions prior to and during nucleation are not necessarily effective proxies for the composition of early stage mixed hydrate nuclei. Rather, microscopic details, (e.g., guest-host interactions and previously neglected cage types) apparently play key roles in determining early stage behavior of mixed hydrates. This work thus provides key foundational concepts and insights for understanding mixed hydrate nucleation.

  11. Absence of net long-term successional facilitation by alder in a boreal Alaska floodplain.

    PubMed

    Stuart Chapin, F; Conway, Alexandra J; Johnstone, Jill F; Hollingsworth, Teresa N; Hollingsworth, Jamie

    2016-11-01

    Long-term experiments provide a way to test presumed causes of successional or environmentally driven vegetation changes. Early-successional nitrogen (N)-fixing plants are widely thought to facilitate productivity and vegetation development on N-poor sites, thus accounting for observed vegetation patterns later in succession. We tested this facilitative impact on vegetation development in a 23-yr field experiment on an Interior Alaska (USA) floodplain. On three replicate early-successional silt bars, we planted late-successional white spruce (Picea glauca) seedlings in the presence and absence of planted seedlings of an early-successional N-fixing shrub, thinleaf alder (Alnus incana). Alder initially facilitated survivorship and growth of white spruce. Within six years, however, after canopy closure, alder negatively affected spruce survivorship and growth. Our three replicate sites followed different successional trajectories. One site was eliminated by erosion and supported no vegetation development during our study. The other two sites, which differed in site moisture, diverged in vegetation composition. Structural equation modeling (SEM) suggested that, in the drier of these two sites, alder inhibited spruce growth directly (presumably by competition) and indirectly through effects mediated by competition with other woody species. However, at the wetter site, alder had both positive and negative effects on spruce growth, with negative effects predominating. Snowshoe hares (Lepus americanus) in alder thickets further reduced height growth of spruce in the wetter site. We conclude that net effects of alder on white spruce, the late-successional dominant, were primarily inhibitory and indirect, with the mechanisms depending on initial site moisture. Our results highlight the importance of long-term research showing that small differences among initial replicate sites can cause divergence in successional trajectories, consistent with individualistic distributions

  12. TOXICITY OF AHR AGONISTS TO FISH EARLY LIFE STAGES

    EPA Science Inventory

    Fish early life stages are exceptionally sensitive to the lethal toxicity of chemicals that act as arylhydrocarbon receptor (AhR) agonists. Toxicity characterizations based on 2,3,7,8-tetrachlorodibenzo-p-dioxin, generally the most potent AhR agonist, support the toxicity equiva...

  13. Radiation Plus Chemotherapy in Early-Stage Hodgkin Lymphoma

    Cancer.gov

    Adding radiation therapy to chemotherapy may improve outcomes in patients with early-stage Hodgkin lymphoma, according to a paper published in the Cochrane Database of Systematic Reviews in February 2011, but the long-term effects of this regimen are not

  14. Early Stages of the Evolution of Life: a Cybernetic Approach

    NASA Astrophysics Data System (ADS)

    Melkikh, Alexey V.; Seleznev, Vladimir D.

    2008-08-01

    Early stages of the evolution of life are considered in terms of control theory. A model is proposed for the transport of substances in a protocell possessing the property of robustness with regard to changes in the environmental concentration of a substance.

  15. [The conservative treatment of early-stage benign prostatic hypertrophy].

    PubMed

    Kumanov, Kh; Stoianova, V; Lilov, A; Kaloianov, D

    1993-01-01

    After outlining the methods currently used in benign prostate hyperplasia (BPH) treatment, data defining some etiological aspects of the disease are briefly analyzed. Initial experience had with the treatment of early stage BPH using Permixon--a drug exerting effect on alpha-2 reductase--is described. The results in a series of twenty-seven patients presenting BPH are encouraging.

  16. Signatures of unfolding in the early stages of protein denaturation

    NASA Astrophysics Data System (ADS)

    Gray, Harry B.; Winkler, Jay R.; Kozak, John J.

    2012-04-01

    A comparative study of the early stages of unfolding of five proteins: cyt c, c-b 562, cyt c‧, azurin, and lysozyme is reported. From crystallographic data, helical regions and intervening non-helical (or 'turning') regions are identified in each. Exploiting a previously introduced geometrical model, the paper describes quantitatively the stepwise extension of a polypeptide chain subject to the geometrical constraint that the spatial relationship among the residues of each triplet is fixed by native-state crystallographic data. Despite differences among the above-cited proteins, remarkable universality of behavior is found in the early stages of unfolding. At the very earliest stages, internal residues in each helical region have a common unfolding history; the terminal residues, however, are extraordinarily sensitive to structural perturbations. Residues in non-helical sections of the polypeptide unfold after residues in the internal helical regions, but with increasing steric perturbation playing a dominant role in advancing denaturation.

  17. Bioaccumulation of lipophilic substances in fish early life stages

    SciTech Connect

    Petersen, G.I.; Kristensen, P.

    1998-07-01

    Accumulation of {sup 14}C-labeled polycyclic aromatic hydrocarbons, naphthalene, phenanthrene, pyrene, and benzo(a)pyrene and polychlorinated biphenyl (PCB) congeners PCB 31 and PCB 105 with a log octanol/water partition coefficient (K{sub ow}) range from 3.37 to 6.5 was investigated in eggs and larvae of zebra fish (Brachydanio rerio), and in larvae of cod (Gadus morhua), herring (Clupea harengus), and turbot (Scophthalmus maximus). Significant differences in the uptake and elimination rate constants between eggs and larvae of zebra fish were seen. The low rate of uptake and the lower elimination rate of eggs did, however, lead to bioconcentration factors (BCFs) comparable to those for larvae. As biotransformation of xenobiotics in embryonic and larval stages was indicated to be insignificant compared to juvenile/adult stages, body burdens of readily biotransformed chemicals may be higher in fish early life stages. Because weight and lipid content did not differ much between the investigated species, the main reason for the variability in BCFs between marine species and freshwater species was considered to be caused by differences in exposure temperatures that affect the degree of biotransformation. Due to the smaller size of larvae and thus an increased total surface of the membranes per unit fish weight, steady-state conditions were reached at a faster r/ate in early life stages than in juvenile/adult life stages. The lipid-normalized bioconcentration factors (BCF{sub L}) were linearly related to K{sub ow} but BCF{sub L} was, in general, higher than K{sub ow}, indicating that octanol is not a suitable surrogate for fish lipids. Differences in bioconcentration kinetics between larvae and juvenile/adult life stages are considered to be the main reason for the higher sensitivity, with respect to external effect concentrations, generally obtained for early life stages of fish.

  18. Benchmarking successional progress in a quantitative food web.

    PubMed

    Boit, Alice; Gaedke, Ursula

    2014-01-01

    Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile previously disjoint bodies of

  19. Benchmarking Successional Progress in a Quantitative Food Web

    PubMed Central

    Boit, Alice; Gaedke, Ursula

    2014-01-01

    Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile previously disjoint bodies of

  20. Folding of Polymer Chains in Early Stage of Crystallization

    NASA Astrophysics Data System (ADS)

    Yuan, Shichen; Miyoshi, Toshikazu

    Understanding the structural formation of long polymer chains in the early stage of crystallization is one of the long-standing problems in polymer science. Using solid state NMR, we investigated chain trajectory of isotactic polypropylene in the mesomorphic nano-domains formed via rapid and deep quenching. Comparison of experimental and simulated 13C-13C Double Quantum (DQ) buildup curves demonstrated that instead of random re-entry models and solidification models, individual chains in the mesomorphic form iPP adopt adjacent reentry sequences with an average folding number of = 3-4 (assuming an adjacent re-entry fraction of of 100%) during mesomorphic formation process via nucleation and growth in the early stage. This work was financially supported by the National Science Foundation (Grant DMR-1105829 and 1408855) and startup funds from the UA.

  1. Maternal warming affects early life stages of an invasive thistle.

    PubMed

    Zhang, R; Gallagher, R S; Shea, K

    2012-09-01

    Maternal environment can influence plant offspring performance. Understanding maternal environmental effects will help to bridge a key gap in the knowledge of plant life cycles, and provide important insights for species' responses under climate change. Here we show that maternal warming significantly affected the early life stages of an invasive thistle, Carduus nutans. Seeds produced by plants grown in warmed conditions had higher germination percentages and shorter mean germination times than those produced by plants under ambient conditions; this difference was most evident at suboptimal germination temperatures. Subsequent seedling emergence was also faster with maternal warming, with no cost to seedling emergence percentage and seedling growth. Our results suggest that maternal warming may accelerate the life cycle of this species via enhanced early life-history stages. These maternal effects on offspring performance, together with the positive responses of the maternal generation, may exacerbate invasions of this species under climate change.

  2. Adjuvant chemotherapy for early-stage cervical cancer

    PubMed Central

    Asano, Hiroshi; Todo, Yukiharu; Watari, Hidemichi

    2016-01-01

    The aim of this review is to address the current status of adjuvant chemotherapy alone in early-stage cervical cancer treatments in the literature. At present, the therapeutic effect of adjuvant chemotherapy alone after radical surgery (RS) has not yet been established, and radiation therapy (RT) or concurrent chemoradiotherapy (CCRT) is recommended as the standard adjuvant therapy after RS for early-stage cervical cancer in various guidelines. The main purpose of adjuvant therapy after RS, however, should be to reduce extrapelvic recurrence rather than local recurrence, although adjuvant RT or CCRT has survival benefits for patients with intermediate- or high-risk factors for recurrence. Moreover, several studies reported that adjuvant therapies including RT were associated with a higher incidence of complications, such as lymphedema, bowel obstruction and urinary disturbance, and a lower grade of long-term quality of life (QOL) or sexual functioning than adjuvant chemotherapy alone. The effect of adjuvant chemotherapy alone for early-stage cervical cancer with intermediate- or high-risk factors for recurrence were not fully investigated in prospective studies, but several retrospective studies suggest that the adjuvant effects of chemotherapy alone are at least similar to that of RT or CCRT in terms of recurrence rate, disease-free survival, or overall survival (OS) with lower incidence of complications. Whereas cisplatin based combination regimens were used in these studies, paclitaxel/cisplatin (TP) regimen, which is currently recognized as a standard chemotherapy regimen for patients with metastatic, recurrent or persistent cervical cancer by Gynecologic Oncology Group (GOG), had also survival benefit as an adjuvant therapy. Therefore, it may be worth considering a prospective randomized controlled trial (RCT) of adjuvant chemotherapy alone using TP regimen versus adjuvant RT as an alternative adjuvant therapy. Because early-stage cervical cancer is a curable

  3. Effects of genistein on early-stage cutaneous wound healing

    SciTech Connect

    Park, Eunkyo; Lee, Seung Min; Jung, In-Kyung; Lim, Yunsook; Kim, Jung-Hyun

    2011-07-08

    Highlights: {yields} We examine the effect of genistein on cutaneous wound healing. {yields} Genistein enhanced wound closure during the early stage of wound healing. {yields} These genistein effects on wound closure were induced by reduction of oxidative stress through increasing antioxidant capacity and modulation of pro-inflammatory cytokine expression. -- Abstract: Wound healing occurs in three sequential phases: hemostasis and inflammation, proliferation, and remodeling. Inflammation, the earliest phase, is considered a critical period for wound healing because immune cells remove damaged tissues, foreign debris, and remaining dead tissue. Wound healing would be delayed without inflammation, and this phase is affected by antioxidation capacity. Therefore, we hypothesized that genistein, which has an antioxidant effect, might modulate the wound healing process by altering the inflammatory response. After three days of acclimation, mice were divided into three groups: control, 0.025% genistein, and 0.1% genistein. After two weeks of an experimental diet, skin wounds were induced. Wounded skin areas were imaged, and the healing rate calculated. To measure lipid peroxidation, antioxidant enzyme expression and activity, and pro-inflammatory cytokine expression, skin and liver tissues were harvested at 12, 24, 48, and 72 h. Genistein did not affect body weight. The rate of wound closure in mice fed genistein was significantly faster than in the control group during the early stage of wound healing, especially in first three days. Cu, Zn-SOD and Mn-SOD expression in wound skin tissue in the 0.1% genistein group was lower than in the control group. However, CAT expression did not differ among groups. We also found that genistein modulated NF-{kappa}B and TNF-{alpha} expression during the early stage of wound healing. The genistein group had significantly lower hepatic lipid peroxidation and higher SOD, CAT, and GPx activities than the control group. These results

  4. Early-stage Alzheimer disease represents increased suicidal risk in relation to later stages.

    PubMed

    Lim, Wee Shiong; Rubin, Eugene H; Coats, Mary; Morris, John C

    2005-01-01

    The level of risk for suicide in individuals with Alzheimer disease (AD) generally is considered to be low. It is important to recognize, however, that suicide can occur in early-stage Alzheimer disease on the background of a distinct high-risk profile. The objective of this report is to describe the clinical profiles of individuals with very mild Alzheimer disease who either attempted or completed suicide. We describe two participants in a longitudinal study of early-stage Alzheimer disease who were in the ninth decade of life and had very mild Alzheimer disease. Consistent with earlier cases reported in the literature, both displayed the following high-risk phenotype predisposing to suicidal risk: male gender, highly educated professional, preserved insight, dysthymic symptoms that did not meet criteria for major depression and post-dated the onset of cognitive decline, and suicidal ideation. Neuropathological examination confirmed histologic Alzheimer disease in both cases. These cases, taken together, emphasize the need for awareness that early-stage Alzheimer disease may present a unique suicidal risk compared with later stages.

  5. Acoustic determination of early stages of intravascular blood coagulation.

    PubMed

    Uzlova, Svetlana G; Guria, Konstantin G; Guria, Georgy Th

    2008-10-13

    The blood coagulation system (BCS) is a complex biological system playing a principal role in the maintenance of haemostasis. Insufficient activity of the BCS may lead to bleeding and blood loss (e.g. in the case of haemophilia). On the other hand, excessive activity may cause intravascular blood coagulation, thromboses and embolization. Most of the methods currently used for BCS monitoring suffer from the major disadvantage of being invasive. The purpose of the present work is to demonstrate the feasibility of using ultrasonic methods for non-invasive registration of the early stages of blood coagulation processes in intensive flows. With this purpose, a special experimental set-up was designed, facilitating the simultaneous detection of optical and acoustic signals during the clotting process. It was shown that (i) as microemboli appear in the flow during the early stage of blood coagulation, the intensity of the Doppler signal increases twofold, and (ii) microemboli formation in the early stages of blood clotting always reveals itself through an acoustic contrast. Both of these effects are well defined, so we hope that they may be used for non-invasive BCS monitoring in clinical practice.

  6. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health.

    PubMed

    Ahmed, Usman; Anwar, Attia; Savage, Richard S; Costa, Matthew L; Mackay, Nicola; Filer, Andrew; Raza, Karim; Watts, Richard A; Winyard, Paul G; Tarr, Joanna; Haigh, Richard C; Thornalley, Paul J; Rabbani, Naila

    2015-03-19

    There is currently no biochemical test for detection of early-stage osteoarthritis (eOA). Tests for early-stage rheumatoid arthritis (eRA) such as rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies require refinement to improve clinical utility. We developed robust mass spectrometric methods to quantify citrullinated protein (CP) and free hydroxyproline in body fluids. We detected CP in the plasma of healthy subjects and surprisingly found that CP was increased in both patients with eOA and eRA whereas anti-CCP antibodies were predominantly present in eRA. A 4-class diagnostic algorithm combining plasma/serum CP, anti-CCP antibody and hydroxyproline applied to a cohort gave specific and sensitive detection and discrimination of eOA, eRA, other non-RA inflammatory joint diseases and good skeletal health. This provides a first-in-class plasma/serum-based biochemical assay for diagnosis and type discrimination of early-stage arthritis to facilitate improved treatment and patient outcomes, exploiting citrullinated protein and related differential autoimmunity.

  7. A shift from arbuscular mycorrhizal to dark septate endophytic colonization in Deschampsia flexuosa roots occurs along primary successional gradient.

    PubMed

    Huusko, K; Ruotsalainen, A L; Markkola, A M

    2017-02-01

    Soil fungal community and dominant mycorrhizal types are known to shift along with plant community changes during primary succession. However, it is not well understood how and why root fungal symbionts and colonization types vary within the plant host when the host species is able to thrive both at young and at old successional stages with different light and nutrient resource availability. We asked (i) how root fungal colonization of Deschampsia flexuosa (Poaceae) by arbuscular mycorrhizal (AM) fungi and dark septate endophytes (DSE) changes along a postglacial primary successional land uplift gradient. As neighboring vegetation may play a role in root fungal colonization, we also asked (ii) whether removal of the dominant neighbor, Empetrum nigrum ssp. hermaphroditum (Ericaceae), affects root fungal colonization of Deschampsia. We also studied whether (iii) foliar carbon (C) and nitrogen (N) concentration of Deschampsia is related to successional changes along a land uplift gradient. AM colonization decreased (-50 %), DSE colonization increased (+200 %), and foliar C declined in Deschampsia along with increasing successional age, whereas foliar N was not affected. Empetrum removal did not affect AM colonization but increased DSE sclerotial colonization especially at older successional stages. The observed decrease in foliar C coincides with an increase in canopy closure along with increasing successional age. We suggest that the shift from an AM-dominated to a DSE-dominated root fungal community in Deschampsia along a land uplift successional gradient may be related to different nutritional benefits gained through these root fungal groups.

  8. High-throughput quantification of early stages of phagocytosis.

    PubMed

    Yeo, Jeremy Changyu; Wall, Adam Alexander; Stow, Jennifer Lea; Hamilton, Nicholas Ahti

    2013-09-01

    Phagocytosis--the engulfment of cells and foreign bodies--is an important cellular process in innate immunity, development, and disease. Quantification of various stages of phagocytosis, especially in a rapid screening fashion, is an invaluable tool for elucidating protein function during this process. However, current methods for assessing phagocytosis are largely limited to flow cytometry and manual image-based assays, providing limited information. Here, we present an image-based, semi-automated phagocytosis assay to rapidly quantitate three distinct stages during the early engulfment of opsonized beads. Captured images are analyzed using the image-processing software ImageJ and quantified using a macro. Modifications to this method allowed quantification of phagocytosis only in fluorescently labeled transfected cells. Additionally, the time course of bead internalization could be measured using this approach. The assay could discriminate perturbations to stages of phagocytosis induced by known pharmacological inhibitors of filamentous actin and phosphoinositol-3-kinase. Our methodology offers the ability to automatically categorize large amounts of image data into the three early stages of phagocytosis within minutes, clearly demonstrating its potential value in investigating aberrant phagocytosis when manipulating proteins of interest in drug screens and disease.

  9. Douglas-fir ectomycorrhizae in 40- and 400-year-old stands: mycobiont availability to late successional western hemlock.

    PubMed

    Horton, T R; Molina, R; Hood, K

    2005-09-01

    We investigated ectomycorrhizal (EM) fungi in forest stands containing both early successional Douglas-fir and late successional western hemlock at two points in the typical stand development by identifying EM fungi from roots of Douglas-fir and western hemlock in mixed stands. In an early seral stage forest, EM roots of western hemlock seedlings and intermingling 40-year-old Douglas-fir were sampled. In a late seral stage forest, EM roots of trees of both species were sampled in a 400-year-old stand. We use molecular approaches to identify the symbionts from field samples in this descriptive study. In the early seral stage study, >95% of the western hemlock root tips by biomass were colonized by fungi also colonizing Douglas-fir roots. This result supports the prediction that western hemlock can associate with fungi in Douglas-fir EM networks. In the same study, fungi specific to Douglas-fir colonized 14% of its EM root tips. In the late seral stage study, 14% of the western hemlock root tips were colonized by fungi also observed in association with Douglas-fir, a result strongly influenced by sampling issues and likely represents a conservative estimate of multiple host fungi in this old growth setting. Fungi specific to Douglas-fir colonized 25% of its root tip biomass in the old growth study, in tight coralloid clusters within five of the 24 soil samples. The trends revealed in this study corroborate earlier studies suggesting a predominance of multiple host fungi in mixed communities of EM plants. The role of host-specific fungi in these stands remains unclear.

  10. Spatial and successional dynamics of microbial biofilm communities in a grassland stream ecosystem

    DOE PAGES

    Veach, Allison M.; Stegen, James C.; Brown, Shawn P.; ...

    2016-09-06

    Biofilms represent a metabolically active and structurally complex component of freshwater ecosystems. Ephemeral prairie streams are hydrologically harsh and prone to frequent perturbation. Elucidating both functional and structural community changes over time within prairie streams provides a general understanding of microbial responses to environmental disturbance. In this study, we examined microbial succession of biofilm communities at three sites in a third-order stream at Konza Prairie over a 2- to 64-day period. Microbial abundance (bacterial abundance, chlorophyll a concentrations) increased and never plateaued during the experiment. Net primary productivity (net balance of oxygen consumption and production) of the developing biofilms didmore » not differ statistically from zero until 64 days suggesting a balance of the use of autochthonous and allochthonous energy sources until late succession. Bacterial communities (MiSeq analyses of the V4 region of 16S rRNA) established quickly. Bacterial richness, diversity and evenness were high after 2 days and increased over time. Several dominant bacterial phyla (Beta-, Alphaproteobacteria, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Chloroflexi) and genera (Luteolibacter, Flavobacterium, Gemmatimonas, Hydrogenophaga) differed in relative abundance over space and time. Bacterial community composition differed across both space and successional time. Pairwise comparisons of phylogenetic turnover in bacterial community composition indicated that early-stage succession (≤16 days) was driven by stochastic processes, whereas later stages were driven by deterministic selection regardless of site. Finally, our data suggest that microbial biofilms predictably develop both functionally and structurally indicating distinct successional trajectories of bacterial communities in this ecosystem.« less

  11. Involvement of 15-lipoxygenase in early stages of atherogenesis

    PubMed Central

    1994-01-01

    The arachidonate 15-lipoxygenase which is expressed in atherosclerotic lesions is implicated in the oxidative modification of low density lipoproteins during atherogenesis. To obtain experimental in vivo evidence for this hypothesis, we analyzed the structure of oxygenated lipids isolated from the aorta of rabbits fed with a cholesterol-rich diet for different time periods and compared the pattern of oxygenation products with that isolated from low density lipoproteins treated in vitro with the pure rabbit 15-lipoxygenase and with oxygenated lipids isolated from advanced human atherosclerotic lesions. In early atherosclerotic lesions (12-wk cholesterol feeding), specific lipoxygenase products were detected whose structure was similar to those isolated from lipoxygenase-treated low density lipoproteins. The appearance of these products did coincide with the lipid deposition in the vessel wall. In later stages of atherogenesis (26-wk cholesterol feeding) the degree of oxidative modification of the tissue lipids did increase but the share of specific lipoxygenase products was significantly lower, suggesting an increasing overlay of the specific lipoxygenase products by nonenzymatic lipid peroxidation. In advanced human atherosclerotic lesions, large amounts of oxygenation products were detected whose structure suggests a nonenzymatic origin. These data suggest that the arachidonate 15-lipoxygenase is of pathophysiological importance during the early stages of atherogenesis. In later stages of plaque development nonenzymatic lipid peroxidation becomes more relevant. PMID:8195716

  12. Early stages of irradiation induced dislocations in urania

    NASA Astrophysics Data System (ADS)

    Chartier, A.; Onofri, C.; Van Brutzel, L.; Sabathier, C.; Dorosh, O.; Jagielski, J.

    2016-10-01

    The early stages of nucleation and growth of dislocations by irradiation in urania is clarified based on the combination of experiments and atomistic calculations. It is established that irradiation induced dislocations follow a five stage process: (i) point defects are first created by irradiation, (ii) they aggregate into clusters, (iii) from which nucleate Frank loops, (iv) which transform into unfaulted loops via Shockley that in turn grow, and (v) finally reorganize into forest dislocations. Stages (i)-(iii) participate in the lattice expansion while the onset of lattice contraction starts with stage (iv), i.e., when unfaulted loops nucleate. Irradiation induced dislocations operate in the spontaneous recombination regime, to be opposed to the thermal diffusion regime. Body of arguments collaborates to this statement, the main one is the comparison between characteristic distances estimated from the dose rate (Vat/(K0×τ ) ) 1/3 and from the diffusion coefficient (D×τ ) 1/2 . Such a comparison identifies materials under irradiation as belonging either into the recombination regime or not.

  13. Effects of genistein on early-stage cutaneous wound healing.

    PubMed

    Park, Eunkyo; Lee, Seung Min; Jung, In-Kyung; Lim, Yunsook; Kim, Jung-Hyun

    2011-07-08

    Wound healing occurs in three sequential phases: hemostasis and inflammation, proliferation, and remodeling. Inflammation, the earliest phase, is considered a critical period for wound healing because immune cells remove damaged tissues, foreign debris, and remaining dead tissue. Wound healing would be delayed without inflammation, and this phase is affected by antioxidation capacity. Therefore, we hypothesized that genistein, which has an antioxidant effect, might modulate the wound healing process by altering the inflammatory response. After three days of acclimation, mice were divided into three groups: control, 0.025% genistein, and 0.1% genistein. After two weeks of an experimental diet, skin wounds were induced. Wounded skin areas were imaged, and the healing rate calculated. To measure lipid peroxidation, antioxidant enzyme expression and activity, and pro-inflammatory cytokine expression, skin and liver tissues were harvested at 12, 24, 48, and 72 h. Genistein did not affect body weight. The rate of wound closure in mice fed genistein was significantly faster than in the control group during the early stage of wound healing, especially in first three days. Cu, Zn-SOD and Mn-SOD expression in wound skin tissue in the 0.1% genistein group was lower than in the control group. However, CAT expression did not differ among groups. We also found that genistein modulated NF-κB and TNF-α expression during the early stage of wound healing. The genistein group had significantly lower hepatic lipid peroxidation and higher SOD, CAT, and GPx activities than the control group. These results suggest that genistein supplementation reduces oxidative stress by increasing antioxidant capacity and modulating proinflammatory cytokine expression during the early stage of wound healing.

  14. Reproductive and early life stages pathology - Histopathology workshop report

    USGS Publications Warehouse

    Bruno, D.W.; Nowak, B.; Elliott, Diane G.

    2006-01-01

    Pathology occurring during reproduction and larval development represents an important part of the life cycle of fish, and the diseases that affect eggs and larvae often result in significant losses. However, mortality during this period is frequently ignored or poorly researched as the temptation is to replace the losses rather than investigate the causes. A histopathology workshop organised at the newly refurnished laboratory within the Danish Veterinary School was an opportunity to discuss the pathology of selected diseases associated with Reproductive and Early Life Stages Pathology. Several people also kindly provided reference slides.

  15. Histopathological diagnosis of acral lentiginous melanoma in early stages.

    PubMed

    Fernandez-Flores, Angel; Cassarino, David S

    2017-02-01

    Acral lentiginous melanoma is a rare variant of melanoma that is associated with a relatively low survival rate. The latter is partly due to the advanced stage in which the tumor is usually diagnosed. The diagnostic delay is mainly due to difficulties in identifying the very early histopathological signs of acral melanoma. The current article is a review of diagnostic clues, concepts, and definitions from the literature, as well as illustrating examples from our own archives. We have sought to provide an article that can be easily consulted in difficult cases of acral lentiginous melanoma.

  16. Late stages of accumulation and early evolution of the planets

    NASA Technical Reports Server (NTRS)

    Vityazev, Andrey V.; Perchernikova, G. V.

    1991-01-01

    Recently developed solutions of problems are discussed that were traditionally considered fundamental in classical solar system cosmogony: determination of planetary orbit distribution patterns, values for mean eccentricity and orbital inclinations of the planets, and rotation periods and rotation axis inclinations of the planets. Two important cosmochemical aspects of accumulation are examined: the time scale for gas loss from the terrestrial planet zone, and the composition of the planets in terms of isotope data. It was concluded that the early beginning of planet differentiation is a function of the heating of protoplanets during collisions with large (thousands of kilometers) bodies. Energetics, heat mass transfer processes, and characteristic time scales of these processes at the early stages of planet evolution are considered.

  17. Suites of plant traits in species from different stages of a Mediterranean secondary succession.

    PubMed

    Navas, M-L; Roumet, C; Bellmann, A; Laurent, G; Garnier, E

    2010-01-01

    The aim of this study was to detect suites of traits related to whole plant and seed morphology, phenology and resource use--including water--in species differing in successional status. Twenty traits were measured on 55 species representative of 5 successional stages in Mediterranean southern France, including eight pertaining to phenology and five to water economy. Suites of traits that changed along succession in agreement with the acquisition/conservation trade-off were completed by continuous changes in phenology. Early successional species had leaves with a high specific leaf area that were produced and lost continuously through the growing season. Late-successional species were taller with long-lived, high delta(13)C leaves produced during short periods, most of them persisting during summer, and produced large seeds requiring a long ripening period. Replacement of species occurred with change in strategies of drought survival: early successional species escaped drought by dying before summer; later herbaceous species maintained favourable water status in relation to leaf shedding during summer; late successional trees with a large body allowing access to a large pool of resources, produced dense leaves that could tolerate desiccation. These changes occurred concomitantly with a shift in CSR strategies, using traits related to resource use, plant size and flowering phenology: ruderal herbs were replaced by more stress-tolerant herbs and shrubs throughout the succession, with competitive trees dominating the latest successional stage. These results suggest that the breadth of functional variability found in natura is not predicted by the CSR framework, and calls for a more integrated view of whole plant functioning.

  18. Prognostic factors in early-stage ovarian cancer

    PubMed Central

    Tognon, Germana; Carnazza, Mario; Ragnoli, Monica; Calza, Stefano; Ferrari, Federico; Gambino, Angela; Zizioli, Valentina; Notaro, Sara; Sostegni, Benedetta; Sartori, Enrico

    2013-01-01

    The purpose of this study was to identify the main prognostic factors in patients with early-stage epithelial ovarian cancer. Data were extracted from 222 patients with initial stage (I–IIA) invasive epithelial ovarian cancer treated with primary surgery followed or not followed by adjuvant therapy, from 1 January 1980 to 31 December 2008, at the Division of Obstetrics and Gynecology, Spedali Civili, Brescia, Italy; the median follow-up was 79 months (SD ± 35,945, range 20–250 months). The negative prognostic factors that were statistically significant (p<0.050) in univariate analysis were grade 2, 3, and X (clear cell in our study); stage IB, IC, IIA; positive peritoneal cytology, age equal to/greater than 54; dense adhesions; capsule rupture (pre-operative or intra-operative) and endometrioid histotype (only for disease-free survival (DFS)). Positive cytology was strongly associated with peritoneal relapses, while adhesions were associated with pelvic relapses. A positive prognosis was associated with the mucinous histotype. Conservative treatment had been carried out in 52% of patients under 40 years of age, and we detected only two relapses and three completions of surgery after a few weeks among 31 women in total. Our study indicated a possible execution in patients with patients with cancer stage IA G1–G2 (p=0.030) or IC G1 (p=0.050), provided well staged. Adjuvant chemotherapy improved the survival of cancers that were not IA G1. The positive prognostic role of taxanes must be emphasised, when used in combination with platino. PMID:23781280

  19. Early stage of nanodroplet impact on solid wall

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kazumichi; Konno, Kazuki; Yaguchi, Hisao; Fujii, Hiroyuki; Sanada, Toshiyuki; Watanabe, Masao

    2016-03-01

    In this study, we investigated nanodroplet spreading at the early stage after the impact using molecular dynamics simulations by changing the magnitude of the intermolecular force between the liquid and wall molecules. We showed that the droplet deformation after the impact greatly depends on the intermolecular force. The temporal evolution of the spreading diameters was measured by the cylindrical control volume for several molecular layers in the vicinity of the wall. At the early stage of the nanodroplet impact, the normalized spreading radius of the droplet is proportional to the square root of the normalized time, t ˆ . This result is understood by the geometrical consideration presented by Rioboo et al. ["Time evolution of liquid drop impact onto solid, dry surfaces," Exp. Fluids 33, 112-124 (2002)]. In addition, we found that as the intermolecular force between the liquid and wall becomes stronger, the normalized spreading diameter of the first molecular layer on the wall remains less dependent on the impact velocity. Furthermore, the time evolution of the droplet spreading changes from √{ t ˆ } to log t ˆ with time.

  20. Sensorimotor Cortical Neuroplasticity in the Early Stage of Bell's Palsy

    PubMed Central

    Dai, Minhui; Xuan, Lihua; Cao, Zhijian; Zhou, Sisi; Lang, Courtney; Lv, Kun

    2017-01-01

    Neuroplasticity is a common phenomenon in the human brain following nerve injury. It is defined as the brain's ability to reorganize by creating new neural pathways in order to adapt to change. Here, we use task-related and resting-state fMRI to investigate neuroplasticity in the primary sensory (S1) and motor cortex (M1) in patients with acute Bell's palsy (BP). We found that the period directly following the onset of BP (less than 14 days) is associated with significant decreases in regional homogeneity (ReHo), fractional amplitude of low frequency fluctuations (fALFF), and intrinsic connectivity contrast (ICC) values in the contralateral S1/M1 and in ReHo and ICC values in the ipsilateral S1/M1, compared to healthy controls. The regions with decreased ReHo, fALFF, and ICC values were in both the face and hand region of S1/M1 as indicated by resting-state fMRI but not task-related fMRI. Our results suggest that the early stages of BP are associated with functional neuroplasticity in both the face and hand regions of S1/M1 and that resting-state functional fMRI may be a sensitive tool to detect these early stages of plasticity in patient populations. PMID:28299208

  1. Early stages during plasma nitriding of pure iron

    SciTech Connect

    Palacios, M.D.; Martinez, O.; Oseguera, J.

    1995-12-31

    The sequence of nitride formation during the early stages of plasma nitriding of pure iron was studied by optical microscopy, SEM, TEM and x-ray diffraction. Plasma nitriding at {approximately}490 C in a 25 vol.%H{sub 2} + 75 vol.%N{sub 2} mixture starts with the formation of {gamma}{prime}-Fe{sub 4}N after 40s. Once {gamma}{prime} nucleates, it mainly spreads laterally due to diffusion shortcuts in the discontinuous surface nitride layer. Before {gamma}{prime} is continuous on the surface, {epsilon} nucleates on top of it shortly after 40S. Epsilon is then observed to grow, both inwardly and laterally along with {gamma}{prime}. A compact {gamma}{prime}/{epsilon} bilayer forms on the surface at around 100s. The kinetics of nucleation, growth and compactation of the nitrides observed in the present work was significantly more rapid than in any of the nitriding process reported in the literature, including plasma nitriding. The acceleration of the nitriding kinetics in the early stages of plasma nitriding may be attributed to enhanced diffusion resulting from a high nitrogen flux from the plasma atmosphere. The results presented are consistent with the findings of a companion work on modeling the kinetics of nitride layer growth.

  2. Understanding early-stage dune development: morphodynamics of aeolian protodunes

    NASA Astrophysics Data System (ADS)

    Baddock, Matthew; Wiggs, Giles; Nield, Joanna

    2016-04-01

    For such a fundamental aspect of bedform development, the initiation and early-stage growth of sand dunes remain poorly understood. Protodunes are bedforms within the continuum of early-stage depositional aeolian features that exist between flat sand patches and small dunes. As transitory bedforms with the potential to develop into dunes, the detailed study of protodune morphodynamics can provide significant insights into nascent dune development. As part of a multi-annual study investigating bedform change through repeat morphological surveys of bedforms with differing maturity, measurements of near-surface airflow and sand transport were conducted over a protodune in a small Namibian barchan dune field. The protodune was approximately 85 m in length and 1 m high, and was without a slipface. Data show that over the course of a week, patterns of airflow and transport flux variation were linked with accretion at the crest, and erosion of the leeside edge showing an increase in protodune height, and providing evidence of the dune's vertical development. Surveys reveal the longer term evolution of the protodune, in the context of changes exhibited by nearby, fully developed barchan dunes, and long term monitoring of wind regime at the site.

  3. Effects of hydroelectric turbine passage on fish early life stages

    SciTech Connect

    Cada, G.F.

    1991-01-01

    Turbine-passage mortality has been studied extensively for juveniles and adults of migratory fish species, but few studies have directly quantified mortality of fish eggs and larvae. An analysis of literature relating to component stresses of turbine passage (i.e., pressure changes, blade contact, and shear) indicates that mortality of early life stages of fish would be relatively low at low-head, bulb turbine installations. The shear forces and pressure regimes normally experienced are insufficient to cause high mortality rates. The probability of contact with turbine blades is related to the size of the fish; less than 5% of entrained ichthyoplankton would be killed by the blades in a bulb turbine. Other sources of mortality (e.g., cavitation and entrainment of fish acclimated to deep water) are controlled by operation of the facility and thus are mitigable. Because turbine-passage mortality among fish early life stages can be very difficult to estimate directly, it may be more fruitful to base the need for mitigation at any given site on detailed knowledge of turbine characteristics and the susceptibility of the fish community to entrainment. 7 refs., 1 fig.

  4. Early stage of Superradiance from Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Buchmann, Lukas

    2011-05-01

    We investigate the dynamics of matter and optical waves at the early stage of superradiant Rayleigh scattering from Bose-Einstein condensates, an instance of four-wave-mixing of matter and optical waves. Our analysis is within a spatially dependent model which treats the matter-waves as well as the optical end-fire modes quantum mechanically and is capable of providing analytic solutions for the operators of interest. In particular, we study the statistical properties of the outgoing scattered light which provide insight into the rich internal dynamics of the system at this early stage. Furthermore, we investigate coherence properties of pairs of counter propagating atomic sidemodes produced during the process. It is shown that these clouds exhibit long-range spatial coherence and strong nonclassical density cross-correlations due to entanglement between the clouds. These findings make this scheme a promising candidate for the production of highly directional nonclassically correlated atomic pulses. Our prediction of number difference squeezing between the clouds was observed in another instance of a four-wave mixing process using metastable helium. Work performed at IESL-FORTH in Crete, Greece

  5. Widespread tau seeding activity at early Braak stages.

    PubMed

    Furman, Jennifer L; Vaquer-Alicea, Jaime; White, Charles L; Cairns, Nigel J; Nelson, Peter T; Diamond, Marc I

    2017-01-01

    Transcellular propagation of tau aggregates may underlie the progression of pathology in Alzheimer's disease (AD) and other tauopathies. Braak staging (B1, B2, B3) is based on phospho-tau accumulation within connected brain regions: entorhinal cortex (B1); hippocampus/limbic system (B2); and frontal and parietal lobes (B3). We previously developed a specific and sensitive assay that uses flow cytometry to quantify tissue seeding activity based on fluorescence resonance energy transfer (FRET) in cells that stably express tau reporter proteins. In a tauopathy mouse model, we have detected seeding activity far in advance of histopathological changes. It remains unknown whether individuals with AD also develop seeding activity prior to accumulation of phospho-tau. We measured tau seeding activity across four brain regions (hippocampus, frontal lobe, parietal lobe, and cerebellum) in 104 fresh-frozen human AD brain samples from all Braak stages. We observed widespread seeding activity, notably in regions predicted to be free of phospho-tau deposition, and in detergent-insoluble fractions that lacked tau detectable by ELISA. Seeding activity correlated positively with Braak stage and negatively with MMSE. Our results are consistent with early transcellular propagation of tau seeds that triggers subsequent development of neuropathology. The FRET-based seeding assay may also complement standard neuropathological classification of tauopathies.

  6. 13 CFR 107.1181 - Interest reserve requirements for Early Stage SBICs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1181 Interest reserve requirements for Early Stage SBICs. (a) Reserve requirement. If you are an Early Stage SBIC with outstanding Leverage, for...

  7. 13 CFR 107.1180 - Required distributions to SBA by Early Stage SBICs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1180 Required distributions to SBA by Early Stage SBICs. (a) Distribution requirement. If you are an Early Stage SBIC with outstanding Leverage, you...

  8. 13 CFR 107.1181 - Interest reserve requirements for Early Stage SBICs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1181 Interest reserve requirements for Early Stage SBICs. (a) Reserve requirement. If you are an Early Stage SBIC with outstanding Leverage, for...

  9. 13 CFR 107.1180 - Required distributions to SBA by Early Stage SBICs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1180 Required distributions to SBA by Early Stage SBICs. (a) Distribution requirement. If you are an Early Stage SBIC with outstanding Leverage, you...

  10. Axial differentiation and early gastrulation stages of the pig embryo.

    PubMed

    Hassoun, Romia; Schwartz, Peter; Feistel, Kerstin; Blum, Martin; Viebahn, Christoph

    2009-12-01

    Differentiation of the principal body axes in the early vertebrate embryo is based on a specific blueprint of gene expression and a series of transient axial structures such as Hensen's node and the notochord of the late gastrulation phase. Prior to gastrulation, the anterior visceral endoderm (AVE) of the mouse egg-cylinder or the anterior marginal crescent (AMC) of the rabbit embryonic disc marks the anterior pole of the embryo. For phylogenetic and functional reasons both these entities are addressed here as the mammalian anterior pregastrulation differentiation (APD). However, mouse and rabbit show distinct structural differences in APD and the molecular blueprint, making the search of general rules for axial differentiation in mammals difficult. Therefore, the pig was analysed here as a further species with a mammotypical flat embryonic disc. Using light and electron microscopy and in situ hybridisation for three key genes involved in early development (sox17, nodal and brachyury), two axial structures of early gastrulation in the pig were identified: (1) the anterior hypoblast (AHB) characterised by increased cellular height and density and by sox17 expression, and (2) the early primitive streak characterised by a high pseudostratified epithelium with an almost continuous but unusually thick basement membrane, by localised epithelial-mesenchymal transition, and by brachyury expression in the epiblast. The stepwise appearance of these two axial structures was used to define three stages typical for mammals at the start of gastrulation. Intriguingly, the round shape and gradual posterior displacement of the APD in the pig appear to be species-specific (differing from all other mammals studied in detail to date) but correlate with ensuing specific primitive streak and extraembryonic mesoderm development. APD and, hence, the earliest axial structure presently known in the mammalian embryo may thus be functionally involved in shaping extraembryonic membranes and

  11. Research on the early planet formation stages with IPE

    NASA Astrophysics Data System (ADS)

    Ingo von Borstel, Olaf; Blum, Jurgen; Schraepler, Rainer

    The early stages of planet formation are characterized by growth of fractal aggregates, starting from (sub-)micrometer-sized grains to (fractal) aggregates of roughly mm size. In the last 20 years a number of experiments on the behaviour and growth mechanisms of aggregates has been carried out. Laboratory experiments are limited due to sedimentation (e.g. Heim and Blum 1998, Wurm et al 2001). Previous long-term microgravity experiments CODAG (Blum et al 2000) and CODAG-SRE (Krause and Blum 2004) were mainly limited by the diffusion of particles, a fact which IPE tries to overcome by means of a particle trap. We present how IPE will help to extend these experimental boundaries and how we plan to utilize IPE. Finally we outline the expectations on the facility from a planet formation point of view in the domain of the mutual interactions, evolution, growth and morphology of fractal aggregates.

  12. Contingency Table Browser − prediction of early stage protein structure

    PubMed Central

    Kalinowska, Barbara; Krzykalski, Artur; Roterman, Irena

    2015-01-01

    The Early Stage (ES) intermediate represents the starting structure in protein folding simulations based on the Fuzzy Oil Drop (FOD) model. The accuracy of FOD predictions is greatly dependent on the accuracy of the chosen intermediate. A suitable intermediate can be constructed using the sequence-structure relationship information contained in the so-called contingency table − this table expresses the likelihood of encountering various structural motifs for each tetrapeptide fragment in the amino acid sequence. The limited accuracy with which such structures could previously be predicted provided the motivation for a more indepth study of the contingency table itself. The Contingency Table Browser is a tool which can visualize, search and analyze the table. Our work presents possible applications of Contingency Table Browser, among them − analysis of specific protein sequences from the point of view of their structural ambiguity. PMID:26664034

  13. Flame acceleration in the early stages of burning in tubes

    SciTech Connect

    Bychkov, Vitaly; Fru, Gordon; Petchenko, Arkady; Akkerman, V'yacheslav; Eriksson, Lars-Erik

    2007-09-15

    Acceleration of premixed laminar flames in the early stages of burning in long tubes is considered. The acceleration mechanism was suggested earlier by Clanet and Searby [Combust. Flame 105 (1996) 225]. Acceleration happens due to the initial ignition geometry at the tube axis when a flame develops to a finger-shaped front, with surface area growing exponentially in time. Flame surface area grows quite fast but only for a short time. The analytical theory of flame acceleration is developed, which determines the growth rate, the total acceleration time, and the maximal increase of the flame surface area. Direct numerical simulations of the process are performed for the complete set of combustion equations. The simulations results and the theory are in good agreement with the previous experiments. The numerical simulations also demonstrate flame deceleration, which follows acceleration, and the so-called ''tulip flames''. (author)

  14. Cell proliferation during the early stages of human eye development.

    PubMed

    Bozanić, Darka; Saraga-Babić, Mirna

    2004-08-01

    The distribution as well as the ultrastructural and biochemical characteristics of proliferating cells in the human eye were investigated in five conceptuses of 5-9 postovulatory weeks, using morphological techniques and Ki-67 immunostaining. The Ki-67 nuclear protein was used as a proliferation marker because of its expression in all phases of the cell cycle except the resting phase (G0). The labelling indices of Ki-67-positive cells were analysed by means of the Kruskal-Wallis ANOVA test and the Wilcoxon matched-pairs test. In the 5th week, mitotic cells were the most numerous between the two layers of the optic cup, the optic cup and stalk, and between the lens pit and the surface ectoderm. During the 6th week, cells were observed in the lens epithelium covering the whole cavity of the lens vesicle as well as in the neuroblast zone and the pigmented epithelium of the retina. At later stages (7th-9th weeks), Ki-67-positive cells were restricted to the anterior lens epithelium, the outer neuroblast zone, and the pigmented retina. Throughout all stages examined, mitotic figures were found lying exclusively adjacent to the intraretinal space. Early in the lens pit, they were confined to the free epithelial surface, and later were facing the cavity of the lens vesicle. The proliferative activity was the most intensive in the 6th week, whereas it decreased significantly in the later stages. Additionally, when proliferative activities were compared, the peripheral retina appeared to be less mature than the central before the 9th week. In the earliest analysed stage, cell proliferation might be associated with the sculpturing of the optic cup and stalk, the cornea, and the lens. In the 6th week, the most intensive proliferation seems to be involved not only in the further morphogenesis of the optic cup and the lens vesicle but also in the retinal neurogenesis. At later stages, the decreased proliferation might participate in the neurogenesis of the outer neuroblast zone

  15. Locomotor function in the early stage of Parkinson's disease.

    PubMed

    Carpinella, Ilaria; Crenna, Paolo; Calabrese, Elena; Rabuffetti, Marco; Mazzoleni, Paolo; Nemni, Raffaello; Ferrarin, Maurizio

    2007-12-01

    The cardinal motor symptoms of Parkinson's disease (PD) have been widely investigated with particular reference to abnormalities of steady-state walking. The great majority of studies, however are related to severe forms of PD patients (phases > = 3 of Hoehn and Yahr scale), where locomotor abnormalities are clearly manifested. Goal of the present study was to quantitatively describe locomotor symptoms in subjects with mild PD. Accordingly, a multitask protocol involving instrumental analysis of steady-state linear walking, initiation of gait, and turning while walking was applied to a group of patients with idiopathic PD in their early clinical stage (phases 1 and 2 of Hoehn and Yahr scale), as well as in age-matched elderly controls. Kinematic, kinetic, and myoelectric measures were obtained by optoelectronic motion analysis, force platform, and telemetric electromyography. Results in PD patients showed a tendency to bradykinetic gait, with reduction of walking speed and cadence. Impairments of gait initiation consisted in reduction of the backward shift of the center of pressure (CoP) and prolongation of the stepping phase. Alterations of the turning task were more consistent and included delayed reorientation of the head toward the new direction, altered head-upper trunk rotational strategy, and adoption of a greater number of steps to complete the turning. It is concluded that patients in the early stage of PD reveal mild alterations of steady-state linear walking and more significant anomalies in the transitional conditions, especially during changes in the travel direction. Quantitative analysis of nonstationary locomotor tasks might be a potentially useful starting point for further studies on the pathophysiology of PD.

  16. White matter development in the early stages of psychosis.

    PubMed

    Peters, Bart D; Karlsgodt, Katherine H

    2015-01-01

    Schizophrenia has been conceptualized as a disorder of both neurodevelopment and a disorder of connectivity. One important aspect of the neurodevelopmental hypothesis is that schizophrenia is no longer thought to have discrete illness time points, but rather a long trajectory of brain changes, spanning many years, across a series of stages of the disease including the prodrome, first episode, and chronic period. As the disease progresses, there is a complex relationship between age related changes and disease related changes. Therefore, neural changes, and specifically white matter based connectivity changes, in schizophrenia may be best conceptualized based on a lifespan trajectory. In this selective review, we discuss healthy changes in white matter integrity that occur with age, as well as changes that occur across illness stages. We further propose a set of models that might explain lifespan changes in white matter integrity in schizophrenia, with the conclusion that the evidence most strongly supports a pattern of disrupted maturation during adolescence, with the potential for later changes that may be a result of disease neurotoxicity, abnormal or excessive aging effects, as well as medication, cohort or other effects. Thus, when considering white matter integrity in psychosis, it is critical to consider age in addition to other contributing factors including disease specific effects. Discovery of the factors driving healthy white matter development across the lifespan and deviations from the normal developmental trajectory may provide insights relevant to the discovery of early treatment interventions.

  17. Minimally invasive surgical staging in early stage ovarian carcinoma: a systematic review and meta-analysis.

    PubMed

    Bogani, Giorgio; Borghi, Chiara; Leone Roberti Maggiore, Umberto; Ditto, Antonino; Signorelli, Mauro; Martinelli, Fabio; Chiappa, Valentina; Lopez, Carlos; Sabatucci, Ilaria; Scaffa, Cono; Indini, Alice; Ferrero, Simone; Lorusso, Domenica; Raspagliesi, Francesco

    2017-02-18

    Few studies investigated the efficacy and safety of minimally invasive surgery (MIS) for the treatment of early stage epithelial ovarian cancer (eEOC). In this context, we aimed to review the current evidence comparing laparoscopy and laparotomic approach for staging procedures in eEOC This systematic review was registered in the International Prospective Register of Systematic Review. Overall, 3,065 patients were included: 1,450 undergoing laparoscopy and 1,615 undergoing laparotomic staging. Patients undergoing laparoscopy experienced a longer (but not statistically significant) operative time (WMD: 28.3 minutes; 95%CI: -2.59, 59.2), lower estimated blood loss (WMD: -156.5 ml; 95%CI: -216.4, -96.5), shorter length of hospital stay (WMD: -3.7 days; 95%CI: -5.2, -2.1) and lower postoperative complication rate (OR: 0.48; 95%CI: 0.29, 0.81) than patients undergoing laparotomy. Upstaging (OR: 0.81; 95%CI: 0.55, 1.20) and cysts' rupture (OR: 1.32; 95%CI: 0.52, 3.38) rates were similar between groups. Laparoscopic staging is associated with a shorter time to chemotherapy than laparotomic procedures (WMD: -5.16 days; 95%CI: -8.68, -1.64). Survival outcomes were not influence by route of surgery. Pooled data suggested that MIS approach is equivalent to laparotomy for the treatment of eEOC and may be superior in terms of perioperative outcomes. However, owing to the low level of evidence of the included studies, further prospective randomized trials are warranted.

  18. Caregiver burden and coping in early-stage Alzheimer disease.

    PubMed

    Zucchella, Chiara; Bartolo, Michelangelo; Pasotti, Chiara; Chiapella, Laura; Sinforiani, Elena

    2012-01-01

    This study was set out to describe caregiver-perceived burden and coping in early-stage Alzheimer disease (AD). A total of 163 consecutive pairs of patients with AD and their principal caregivers were initially recruited. The caregivers completed the Caregiver Burden Inventory (CBI) and the Coping Orientations to Problems Experienced scale, and also provided sociodemographic information; the patients with AD were assessed by means of the Mini Mental State Examination and the Neuropsychiatric Inventory. Data from 126 patient-caregiver pairs were analyzed. The caregivers (mean age 56.11±12.37 y) were mainly women (76%); 64% were the patient's offspring; 39% lived with the patient. From the CBI data, it emerged that caregivers perceived loss of personal time (objective burden, 33%) and the feeling of missing out on opportunities (developmental burden, 25%) as their main stressors. Total CBI score was negatively correlated with Mini Mental State Examination (P=0.005). As regards coping strategies, the caregivers predominantly used problem-oriented strategies associated with a positive attitude. The use of dysfunctional strategies was predictive of caregiver burden. It is important to be aware that avoidance and dysfunctional coping strategies predispose caregivers of patients with AD to higher level of distress, whereas successful caregiving seems to be based on the use of problem-oriented strategies early in the disease when solutions are still available.

  19. Treatment of early-stage Hodgkin lymphoma.

    PubMed

    Engert, Andreas; Raemaekers, John

    2016-07-01

    Hodgkin lymphoma (HL) has become one of the best curable malignancies today. This is particularly true for patients with early-stage disease. Today, most patients in this risk group are treated with a combination of chemotherapy followed by small-field radiotherapy. More recent clinical trials such as the German Hodgkin Study Group (GHSG) HD10 study demonstrated, that even two cycles of ABVD followed by 20 Gy involved-field radiation therapy (IF-RT) are sufficient and result in more than 90% of patients being cured. The current treatment for early unfavorable patients is either four cycles of ABVD plus 30 Gy IF-RT or two cycles of BEACOPPbaseline followed by two cycles of ABVD plus IF-RT. Here, the European Organization for Research and Treatment of Cancer (EORTC) demonstrated that in positron emission tomography (PET)-positive patients after two cycles of ABVD, treatment switched to two cycles of BEACOPPbaseline plus radiotherapy results in significantly improved outcomes. Other aspects including attempts to further reduce intensity of treatment will be discussed.

  20. Native language change during early stages of second language learning.

    PubMed

    Bice, Kinsey; Kroll, Judith F

    2015-11-11

    Research on proficient bilinguals has demonstrated that both languages are always active, even when only one is required. The coactivation of the two languages creates both competition and convergence, facilitating the processing of cognate words, but slowing lexical access when there is a requirement to engage control mechanisms to select the target language. Critically, these consequences are evident in the native language (L1) as well as in the second language (L2). The present study questioned whether L1 changes can be detected at early stages of L2 learning and how they are modulated by L2 proficiency. Native English speakers learning Spanish performed an English (L1) lexical decision task that included cognates while event-related potentials were recorded. They also performed verbal fluency, working memory, and inhibitory control tasks. A group of matched monolinguals performed the same tasks in English only. The results revealed that intermediate learners demonstrate a reduced N400 for cognates compared with noncognates in English (L1), and an emerging effect is visually present in beginning learners as well; however, no behavioral cognate effect was present for either group. In addition, slower reaction times in English (L1) are related to a larger cognate N400 magnitude in English (L1) and Spanish (L2), and to better inhibitory control for learners but not for monolinguals. The results suggest that contrary to the claim that L2 affects L1 only when L2 speakers are highly proficient, L2 learning begins to impact L1 early in the development of the L2 skill.

  1. Native language change during early stages of second language learning

    PubMed Central

    Bice, Kinsey; Kroll, Judith F.

    2015-01-01

    Research on proficient bilinguals has demonstrated that both languages are always active, even when only one is required. The co-activation of the two languages creates both competition and convergence, facilitating the processing of cognate words, but slowing lexical access when there is a requirement to engage control mechanisms to select the target language. Critically, these consequences are evident in the native language (L1) as well as the second language (L2). The present study asked whether L1 change can be detected at early stages of L2 learning and how it is modulated by L2 proficiency. Native English speakers learning Spanish performed an English (L1) lexical decision task that included cognates while event-related potentials (ERPs) were recorded. They also performed verbal fluency, working memory, and inhibitory control tasks. A group of matched monolinguals performed the same tasks in English only. The results revealed that intermediate learners demonstrate a reduced N400 for cognates compared to noncognates in English (L1), and an emerging effect is visually present in beginning learners as well; however, no behavioral cognate effect was present for either group. Additionally, slower reaction times in English (L1) are related to a larger cognate N400 magnitude in English (L1) and Spanish (L2), and to better inhibitory control for learners but not for monolinguals. The results suggest that contrary to the claim that the L2 affects the L1 only when L2 speakers are highly proficient, L2 learning begins to impact the L1 early in the development of L2 skill. PMID:26351964

  2. Silicon: The key element in early stages of biocalcification.

    PubMed

    Matsko, Nadejda B; Znidaršič, Nada; Letofsky-Papst, Ilse; Dittrich, Maria; Grogger, Werner; Strus, Jasna; Hofer, Ferdinand

    2011-04-01

    Biocalcification is a widespread process of forming hard tissues like bone and teeth in vertebrates. It is also a topic connecting life sciences and earth sciences: calcified skeletons and shells deposited as sediments represent the earth's fossil record and are of paramount interest for biogeochemists trying to get an insight into the past of our planet. This study reports on the role of silicon in the early biocalcification steps, where silicon and calcium were detected on the surface of cyanobacteria (initial stage of lacustrine calcite precipitation) and in crustacean cuticles. By using innovative methodological approaches of correlative microscopy (AFM in combination with analytical TEM: EFTEM, EELS) the chemical form of silicon in biocalcifying matrices and organic-inorganic particles is determined. Previously, silicon was reported to be localized in active growth areas in the young bone of vertebrates. We have found evidence that biocalcification in evolutionarily distant organisms involves very similar initial phases with silicon as a key element at the organic-inorganic interface.

  3. Cytonuclear incompatibility contributes to the early stages of speciation.

    PubMed

    Barnard-Kubow, Karen B; So, Nina; Galloway, Laura F

    2016-12-01

    Genetic incompatibility is a hallmark of speciation. Cytonuclear incompatibilities are proposed to be among the first genetic barriers to arise during speciation. Accordingly, reproductive isolation (RI) within species should be heavily influenced by interactions between the organelle and nuclear genomes. However, there are few clear examples of cytonuclear incompatibility within a species. Here, we show substantial postzygotic RI in first-generation hybrids between differentiated populations of an herbaceous plant (up to 92% reduction in fitness). RI was primarily due to germination and survival, with moderate RI for pollen viability. RI for survival was asymmetric and caused by cytonuclear incompatibility, with the strength of incompatibility linearly related to chloroplast genetic distance. This cytonuclear incompatibility may be the result of a rapidly evolving plastid genome. Substantial asymmetric RI was also found for germination, but was not associated with cytonuclear incompatibility, indicating endosperm or maternal-zygote incompatibilities. These results demonstrate that cytonuclear incompatibility contributes to RI within species, suggesting that initial rates of speciation could be influenced by rates of organelle evolution. However, other genetic incompatibilities are equally important, indicating that even at early stages, speciation can be a complex process involving multiple genes and incompatibilities.

  4. Life satisfaction of women in early stages of fertility treatment.

    PubMed

    Ben Shlomo, Shirley; Pascal, Mor; Taubman Ben-Ari, Orit; Azuri, Yoseph; Horowtz, Eran

    2016-04-19

    As many women perceive motherhood to be a central component of identity that enhances life satisfaction, difficulties conceiving may lead to stress. This study examined women in the early stages of fertility treatment to ascertain the relations of perceived stress, cognitive appraisal, and self-mastery to the life satisfaction of women embarking on fertility treatment and whether the associations were the same for women who were already mothers versus those who were not. Women were recruited for the study over a period of 18 months, from January 2013 to June 2014. The final sample was composed of 145 women; of these, 67 had 1 or 2 children and 78 had no children. No significant differences were found in perceived stress and life satisfaction between women with and without children. However, in the sample as a whole, higher levels of self-mastery and lower levels of stress were associated with greater life satisfaction. Moreover, the associations between self-mastery and cognitive appraisals of threat and self-efficacy were mediated by perceived stress. The findings highlight the importance of developing interventions at fertility clinics that begin at the very first point of contact to promote the psychological well-being of women being treated for infertility.

  5. Endoscopic mucosal resection of early stage colon neuroendocrine carcinoma

    PubMed Central

    Yamasaki, Yasushi; Uedo, Noriya; Ishihara, Ryu; Tomita, Yasuhiko

    2015-01-01

    Early stage colorectal neuroendocrine carcinoma is rare. A small colon tumour was found in a 56-year-old man during diagnostic colonoscopy performed after a positive faecal occult blood test, and he was referred for treatment. A slightly reddish superficial elevated lesion with a shallow depression 10 mm in size was found in the transverse colon. Magnifying narrow-band imaging revealed disrupted irregular microvessels and the absence of a surface pattern in the depressed area. En bloc endoscopic mucosal resection (EMR) of the tumour was undertaken. The tumour was positive for chromogranin A and synaptophysin, and had a mitotic rate of >20/10 high-power fields and a Ki-67 proliferative index of >50%; it was diagnosed as a neuroendocrine carcinoma. The tumour minimally invaded the submucosa (300 μm) without lymphovascular involvement. The patient was followed up carefully, and at 1 year after EMR, no recurrence was found using colonoscopy and CT scans. PMID:25737221

  6. Toxicity of TFM lampricide to early life stages of walleye

    USGS Publications Warehouse

    Seelye, J.G.; Marking, L.L.; King, E.L.; Hanson, L.H.; Bills, T.D.

    1987-01-01

    The authors studied the effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on gametes, newly fertilized eggs, eyed eggs, larvae, and swim-up fry of the walleye Stizostedion vitreum . When gametes from sexually mature walleyes were stripped into solutions of TFM, no effects were observed during the fertilization process at concentrations up to 3.0 mg/L - three times the concentration lethal to 99.9% of larval sea lampreys Petromyzon marinus held 12 h (LC99.9) under the same test conditions. Newly fertilized eggs likewise were unaffected during water hardening by concentrations of TFM that were lethal to sea lamprey ammocoetes. Eyed eggs, sac fry, and swim-up fry yielded LC25 values that were 2.5 to 5 times greater than the 12-h LC99.9 for sea lamprey ammocoetes. The data thus indicated that all of the early life stages of walleyes tested were considerably more resistant than sea lamprey ammocoetes to TFM, and that it is unlikely they would be adversely affected by standard stream treatments to kill sea lamprey ammocoetes.

  7. Blood biomarkers in the early stage of cerebral ischemia.

    PubMed

    Maestrini, I; Ducroquet, A; Moulin, S; Leys, D; Cordonnier, C; Bordet, R

    2016-03-01

    In ischemic stroke patients, blood-based biomarkers may be applied for the diagnosis of ischemic origin and subtype, prediction of outcomes and targeted treatment in selected patients. Knowledge of the pathophysiology of cerebral ischemia has led to the evaluation of proteins, neurotransmitters, nucleic acids and lipids as potential biomarkers. The present report focuses on the role of blood-based biomarkers in the early stage of ischemic stroke-within 72h of its onset-as gleaned from studies published in English in such patients. Despite growing interest in their potential role in clinical practice, the application of biomarkers for the management of cerebral ischemia is not currently recommended by guidelines. However, there are some promising clinical biomarkers, as well as the N-methyl-d-aspartate (NMDA) peptide and NMDA-receptor (R) autoantibodies that appear to identify the ischemic nature of stroke, and the glial fibrillary acidic protein (GFAP) that might be able to discriminate between acute ischemic and hemorrhagic strokes. Moreover, genomics and proteomics allow the characterization of differences in gene expression, and protein and metabolite production, in ischemic stroke patients compared with controls and, thus, may help to identify novel markers with sufficient sensitivity and specificity. Additional studies to validate promising biomarkers and to identify novel biomarkers are needed.

  8. The Early Stages of Groundwater-fed River Bifurcation

    NASA Astrophysics Data System (ADS)

    Yi, R.; Seybold, H. F.; Gibbins, G.; Rothman, D.

    2014-12-01

    Recent work shows, both theoretically and empirically, that river networks fed by subsurface flow bifurcate on average at an angle of 2π/5 [1]. However, the network's existence within a complex natural framework obscures the emergence of this pattern. Fortunately, this ambiguity betrays the presence of processes that have had some effect on the channels during the network's long history. In particular, we concern ourselves with the signature of the third dimension - the topographic relief - on the early stages of channel bifurcation. While, on average, channels grow in a direction dictated by the shape of the groundwater table, we hypothesize that the valley relief plays a crucial role in determining the opening angle and its relaxation to 2π/5 in this regime. A network-wide averaging of several thousand channel bifurcations driven by subsurface flow on the Florida Panhandle reveals that rivers on average branch initially at an angle wider than 2π/5, yet quickly relax to 2π/5 after a few meters. We hypothesize that this initial wide growth direction is governed by the shape of the topography. As these channels form independent valleys, the Laplacian field prevails, yielding an emergent 2π/5 branching angle. Our results therefore suggest that the path-selection of incipient channels fed by subsurface flow is coupled both to the local topography and the surrounding groundwater field. 1. Devauchelle, Olivier, et al. "Ramification of stream networks." Proceedings of the National Academy of Sciences 109.51 (2012): 20832-20836.

  9. Affective Motives for Smoking Among Early Stage Smokers

    PubMed Central

    Wahlquist, Amy E.; Garrett-Mayer, Elizabeth; Gray, Kevin M.; Saladin, Michael E.; Carpenter, Matthew J.

    2014-01-01

    Background: As most smokers initiate smoking during adolescence, assessment of smoking motives that underlie trajectories of dependence is critical for both prevention and cessation efforts. In the current study, we expected participants with higher nicotine dependence would smoke (a) less for positive reinforcement (PR) and (b) more for negative reinforcement (NR) motives. We secondarily assessed the relative contribution of PR to NR motives across levels of dependence. Methods: Data were drawn from a study on cue-elicited craving among occasional versus daily adolescent smokers aged 16–20 years (N = 111). Smoking motives were assessed in relation to 3 commonly used measures of nicotine dependence: (a) Fagerström Test for Nicotine Dependence (FTND), (b) Autonomy over Smoking Scale (AUTOS), and (c) Nicotine Dependence Syndrome Scale (NDSS). Results: Compared to occasional smokers, daily smokers had significantly higher scores on each dependence measure and endorsed more prominent NR smoking motives. Each measure of nicotine dependence was strongly associated with NR motives for smoking, although measures differed in their association with PR motives. As expected, the FTND, AUTOS, and NDSS each significantly predicted smoking motive difference score (PR − NR), such that higher dependence was associated with more prominent NR motives for smoking. Conclusions: Results are consistent with our understanding of dependence and provide further support for 3 common measures of nicotine dependence among early stage smokers. PMID:24924155

  10. Protein dynamics modulated electron transfer kinetics in early stage photosynthesis

    NASA Astrophysics Data System (ADS)

    Kundu, Prasanta; Dua, Arti

    2013-01-01

    A recent experiment has probed the electron transfer kinetics in the early stage of photosynthesis in Rhodobacter sphaeroides for the reaction center of wild type and different mutants [Science 316, 747 (2007)]. By monitoring the changes in the transient absorption of the donor-acceptor pair at 280 and 930 nm, both of which show non-exponential temporal decay, the experiment has provided a strong evidence that the initial electron transfer kinetics is modulated by the dynamics of protein backbone. In this work, we present a model where the electron transfer kinetics of the donor-acceptor pair is described along the reaction coordinate associated with the distance fluctuations in a protein backbone. The stochastic evolution of the reaction coordinate is described in terms of a non-Markovian generalized Langevin equation with a memory kernel and Gaussian colored noise, both of which are completely described in terms of the microscopics of the protein normal modes. This model provides excellent fits to the transient absorption signals at 280 and 930 nm associated with protein distance fluctuations and protein dynamics modulated electron transfer reaction, respectively. In contrast to previous models, the present work explains the microscopic origins of the non-exponential decay of the transient absorption curve at 280 nm in terms of multiple time scales of relaxation of the protein normal modes. Dynamic disorder in the reaction pathway due to protein conformational fluctuations which occur on time scales slower than or comparable to the electron transfer kinetics explains the microscopic origin of the non-exponential nature of the transient absorption decay at 930 nm. The theoretical estimates for the relative driving force for five different mutants are in close agreement with the experimental estimates obtained using electrochemical measurements.

  11. Dream features in the early stages of Parkinson's disease.

    PubMed

    Bugalho, Paulo; Paiva, Teresa

    2011-11-01

    Few studies have investigated the relation between dream features and cognition in Parkinson's disease (PD), although vivid dreams, hallucinations and cognitive decline have been proposed as successive steps of a pathological continuum. Our objectives were therefore to characterize the dreams of early stage PD and to study the relation between dream characteristics, cognitive function, motor status, depression, dopaminergic treatment, and the presence of REM sleep behaviour disorder (RBD) and hallucinations. Dreams of 19 male PD patients and 21 matched control subjects were classified according to Hall and van de Castle system. h statistics was used to compare the dream content between patients and controls. We tested the relation between patients' dreams characteristics and cognitive function (Frontal assessment battery (FAB) and Mini-Mental State Examination tests) depression (Beck depression inventory), motor function (UPDRS), dopaminergic treatment, the presence of RBD (according to clinical criteria) and hallucinations, using general linear model statistics. Patients and controls differed only on FAB scores. Relevant differences in the Hall and van de Castle scale were found between patient's dreams and those of the control group, regarding animals, aggression/friendliness, physical aggression, befriender (higher in the patient group) and aggressor and bodily misfortunes (lower in the patient group) features. Cognitive and particularly frontal dysfunction had a significant influence on the frequency of physical aggression and animal related features, while dopaminergic doses, depressive symptoms, hallucinations and RBD did not. We found a pattern of dream alteration characterized by heightened aggressiveness and the presence of animals. These were related to more severe frontal dysfunction, which could be the origin of such changes.

  12. [Effects of early growth stage shading on rice flag leaf physiological characters and grain growth at grain-filling stage].

    PubMed

    Liu, Qi-hua; Zhou, Xue-biao; Yang, Lian-qun; Li, Tian; Zhang, Jian-jun

    2009-09-01

    In a pot experiment, rice plants were shaded during the period from transplanting to booting, aimed to study the effects of early growth stage shading on the rice growth at grain-filling stage. Comparing with the control, early growth stage shading decreased the tiller number by 26.72%, but increased the flag leaf area and soluble sugar content by 33.86% and 30.23%, respectively. The filled-grain number per panicle, 1000-grain mass, ultimate brown rice mass, and maximum and average grain-filling rates decreased by 8.65%, 4.81%, 9.74%, 20.22%, and 19.13%, and the effective panicle number and grain yield declined by 25.26% and 39.56%, respectively. The peak time of grain-filling rate (Tm) advanced 1.66 days, while the grain-filling time (T99) prolonged 6.80 days. For shading-tolerance variety, its flag leaf Chl a, Chl b, and Chl (a + b) contents at early and mid grain-filling stages, and the protein N and soluble sugar contents and Chl a/b in its flag leaves at grain-filling stage all increased under early growth stage shading, and the ultimate brown rice mass and 1000-grain mass maintained at the similar levels as the control. Consequently, its grain yield reduction rate was lower than that of shading-sensitive variety.

  13. Susceptibility of early life stages of Xenopus laevis to cadmium

    SciTech Connect

    Herkovits, J.; Perez-Coll, C.S.; Cardellini, P.; Pavanati, C.

    1997-02-01

    The susceptibility of Xenopus laevis to cadmium during different stages of development was evaluated by exposing embryos to cadmium concentrations ranging from 0.1 to 10 mg Cd{sup 2+}/L for 24, 48, and 72 h and assessing lethality and malformations. Susceptibility increased from the two blastomeres stage (stage 2) to stage 40, in which the 24-h LC100 was 1.13 mg Cd{sup 2+}/L, and resistance increased from this stage onward. Malformations occurred at all developmental stages evaluated, the most common being reduced size, incurvated axis, underdeveloped or abnormally developed fin, microcephaly, and microphtalmy. Scanning electron microscopy revealed changes in the ectodermal surface ranging from slightly vaulted cells to a severe reduction in the number of ciliated cells as the concentration of cadmium increased. The intraspecific variation evaluated in embryos (from four sets of parents) at seven developmental stages, expressed as the coefficient of variation of the LC100, ranged from 10 to 112% and reflects the capacity of Xenopus laevis to adapt to changing environmental conditions at different embryonic stages.

  14. Floristic and vegetation successional processes within landslides in a Mediterranean environment.

    PubMed

    Neto, Carlos; Cardigos, Patrícia; Oliveira, Sérgio Cruz; Zêzere, José Luís

    2017-01-01

    Floristic and vegetation analysis in seven Mediterranean landslides led to the understanding of the successional processes occurring in different landslide disturbed sectors. Our study showed that in landslides that occurred between 1996 and 2010 there is a clear differentiation between the three main landslide sectors (scarp, main body and foot) concerning floristic composition, vegetation structure, floristic richness, successional processes and plant functional type. Additional differences were found between landslide areas and undisturbed agricultural areas adjacent to landslides. In this study 48 floristic relevés were made using a stratified random sampling design. The main landslide body exhibits the highest floristic richness whereas the landslide scarp has the lowest coverage rate and the highest presence of characteristic species from ruderal and strongly perturbed habitats. Finally, the landslide foot shows a late stage in the succession (maquis or pre-forest stage) with a high dominance of vines. We further discuss the importance of landslides as reservoirs of biodiversity especially for Mediterranean orchids.

  15. To Stay or to Go? Narratives of Early-Stage Sociologists about Persisting in Academia

    ERIC Educational Resources Information Center

    Wöhrer, Veronika

    2014-01-01

    Based on analyses of life course questionnaires, semi-structured qualitative interviews and focus group interviews carried out with early-stage sociologists over a period of 8 years, this paper presents analyzes of continuity and change in the decisions made by early-stage researchers in regard to their work and careers. The longitudinal approach…

  16. Hydraulic compensation in northern Rocky Mountain conifers: does successional position and life history matter?

    PubMed

    Sala, Anna

    2006-08-01

    As trees grow tall and the resistance of the hydraulic pathway increases, water supply to foliage may decrease forcing stomata to close and CO2 uptake to decline. Several structural (e.g. biomass allocation) and physiological adjustments, however, may partially or fully compensate for such hydraulic constraints and prevent limitations on CO2 uptake and growth. The degree to which trees compensate for hydraulic constraints as they grow tall may depend on the costs and benefits associated with hydraulic compensation according to their ecology and life history. Because later successional Rocky Mountain conifers are more shade tolerant, optimization of CO2 uptake as trees grow tall and shade increases may confer greater benefits than in earlier successional species. If so, higher compensation for hydraulic constraints is expected in later successional species relative to co-occurring earlier successional species. I have examined height-related changes of crown stomatal conductance on a leaf area basis (G(LA)) and leaf to sapwood ratios (A(L):A(S)) for five conifer species in the northern Rocky Mountains. Species were arranged in pairs, each pair consisting of an early and late successional species. For high elevations I used, respectively, whitebark pine (Pinus albicaulis) and subalpine fir (Abies lasiocarpa); for mid-elevations, western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii); for lower elevations, ponderosa pine (Pinus ponderosa) and Douglas-fir. A(L):A(S) either decreased (subalpine fir, ponderosa pine), remained constant (Douglas-fir, western larch) or increased (whitebark pine) with tree height. As hypothesized, earlier successional species (ponderosa pine, whitebark pine and western larch) exhibited significantly stronger decreases of G(LA) with tree height relative to their later successional pairs (Douglas-fir and subalpine fir), which fully compensated for height-related hydraulic constraints on G(LA). A life history approach that

  17. Selection occurs within linear fruit and during the early stages of reproduction in Robinia pseudoacacia

    PubMed Central

    2014-01-01

    Background Pollen donor compositions differ during the early stages of reproduction due to various selection mechanisms. In addition, ovules linearly ordered within a fruit have different probabilities of reaching maturity. Few attempts, however, have been made to directly examine the magnitude and timing of selection, as well as the mechanisms during early life stages and within fruit. Robinia pseudoacacia, which contains linear fruit and non-random ovule maturation and abortion patterns, has been used to study the viability of selection within fruit and during the early stages of reproduction. To examine changes in the pollen donor composition during the early stages of reproduction and of progeny originating from different positions within fruit, paternity analyses were performed for three early life stages (aborted seeds, mature seeds and seedlings) in the insect-pollinated tree R. pseudoacacia. Results Selection resulted in an overall decrease in the level of surviving selfed progeny at each life stage. The greatest change was observed between the aborted seed stage and mature seed stage, indicative of inbreeding depression (the reduced fitness of a given population that occurs when related individual breeding was responsible for early selection). A selective advantage was detected among paternal trees. Within fruits, the distal ends showed higher outcrossing rates than the basal ends, indicative of selection based on the order of seeds within the fruit. Conclusions Our results suggest that selection exists both within linear fruit and during the early stages of reproduction, and that this selection can affect male reproductive success during the early life stages. This indicates that tree species with mixed-mating systems may have evolved pollen selection mechanisms to increase the fitness of progeny and adjust the population genetic composition. The early selection that we detected suggests that inbreeding depression caused the high abortion rate and low

  18. Using Motivational Interviewing within the Early Stages of Group Development

    ERIC Educational Resources Information Center

    Young, Tabitha L.

    2013-01-01

    This article presents developmentally appropriate applications of Motivational Interviewing (MI; Miller & Rollnick, 2002) for use in preparing group members for the working stages of group. Practical strategies are offered for using MI to facilitate an atmosphere of trust, recognize member readiness for change, identify and resolve members'…

  19. POLLUTION PREVENTION IN THE EARLY STAGES OF HIERARCHICAL PROCESS DESIGN

    EPA Science Inventory

    Hierarchical methods are often used in the conceptual stages of process design to synthesize and evaluate process alternatives. In this work, the methods of hierarchical process design will be focused on environmental aspects. In particular, the design methods will be coupled to ...

  20. Efficient embryonic culture method for the Japanese striped snake, Elaphe quadrivirgata, and its early developmental stages.

    PubMed

    Matsubara, Yoshiyuki; Sakai, Atsushi; Kuroiwa, Atsushi; Suzuki, Takayuki

    2014-10-01

    The morphogenesis of snake embryos is an elusive yet fascinating research target for developmental biologists. However, few data exist on development of early snake embryo due to limited availability of pregnant snakes, and the need to harvest early stage embryos directly from pregnant snakes before oviposition without knowing the date of fertilization. We established an ex vivo culture method for early snake embryos using the Japanese striped snake, Elaphe quadrivirgata. This method, which we named "sausage-style (SS) culture", allows us to harvest snake embryos at specific stages for each experiment. Using this SS culture system, we calculated somite formation rate at early stages before oviposition. The average somite formation rate between 6/7 and 12/13 somite stages was 145.9 min, between 60/70 and 80/91 somite stages 42.4 min, and between 113-115 and 126/127 somite stages 71 min. Thus, somite formation rate that we observed during early snake embryogenesis was changed over time. We also describe a developmental staging series for E. quadrivirgata. This is the first report of a developmental series of early snake embryogenesis prior to oviposition by full-color images with high-resolution. We propose that the SS culture system is an easy method for treating early snake embryos ex vivo.

  1. Swimming speed alteration in the early developmental stages of Paracentrotus lividus sea urchin as ecotoxicological endpoint.

    PubMed

    Morgana, Silvia; Gambardella, Chiara; Falugi, Carla; Pronzato, Roberto; Garaventa, Francesca; Faimali, Marco

    2016-04-01

    Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations.

  2. ERP Evidence of Visualization at Early Stages of Visual Processing

    ERIC Educational Resources Information Center

    Page, Jonathan W.; Duhamel, Paul; Crognale, Michael A.

    2011-01-01

    Recent neuroimaging research suggests that early visual processing circuits are activated similarly during visualization and perception but have not demonstrated that the cortical activity is similar in character. We found functional equivalency in cortical activity by recording evoked potentials while color and luminance patterns were viewed and…

  3. Early Years Foundation Stage: How Much Does It Count?

    ERIC Educational Resources Information Center

    Thompson, Ian

    2008-01-01

    The final report of the Williams committee (DCSF, 2008: 68) argues that the revised mathematics Framework (DfES, 2006) "should be reconsidered to achieve a more suitable, user-friendly form." It might also have added that there is not much help and support in it for early years teachers. A much more useful document is the "Practice guidance for…

  4. CMB quadrupole suppression. II. The early fast roll stage

    NASA Astrophysics Data System (ADS)

    Boyanovsky, D.; de Vega, H. J.; Sanchez, N. G.

    2006-12-01

    Within the effective field theory of inflation, an initialization of the classical dynamics of the inflaton with approximate equipartition between the kinetic and potential energy of the inflaton leads to a brief fast roll stage that precedes the slow roll regime. The fast roll stage leads to an attractive potential in the wave equations for the mode functions of curvature and tensor perturbations. The evolution of the inflationary perturbations is equivalent to the scattering by this potential and a useful dictionary between the scattering data and observables is established. Implementing methods from scattering theory we prove that this attractive potential leads to a suppression of the quadrupole moment for CMB and B-mode angular power spectra. The scale of the potential is determined by the Hubble parameter during slow roll. Within the effective field theory of inflation at the grand unification (GUT) energy scale we find that if inflation lasts a total number of e-folds Ntot˜59, there is a 10% 20% suppression of the CMB quadrupole and about 2% 4% suppression of the tensor quadrupole. The suppression of higher multipoles is smaller, falling off as 1/l2. The suppression is much smaller for Ntot>59, therefore if the observable suppression originates in the fast roll stage, there is the upper bound Ntot˜59.

  5. Radiotherapy Alone for Early-Stage Squamous Cell Carcinoma of the Larynx and Hypopharynx

    SciTech Connect

    Foote, Robert L.

    2007-10-01

    Purpose: To describe and illustrate examples of early-stage larynx and hypopharynx cancer that can be successfully treated with radiotherapy alone. Methods and Materials: Review of the NCCN and ASCO practice guidelines. Representative examples are included. Results: Early-stage larynx and hypopharynx cancer is defined by tumor extent based on physical and imaging examination. Conclusions: Radiotherapy alone is appropriate treatment for properly selected early-stage squamous cell carcinoma of the larynx and hypopharynx. The NCCN and ASCO practice guidelines can be an aid to the clinician in identifying favorable cancers that can be successfully treated with radiotherapy alone with preservation of organ function.

  6. [Anxiety-phobic disorders in the early childhood stage].

    PubMed

    Volkova, O M; Kozlovskaia, G V; Proselkova, M O

    2012-01-01

    The complex of such phenomena as anxiety and fear in children of the early age and their relationship with risk factors for psychic pathology were investigated. Eighty cases of anxiety-phobic disorders in children of the first five years of life were studied. The types of behavioral and somatic reactions that allowed to reveal not only the clinically expressed phenomena of anxiety and fear but the higher readiness to them were described. The first anxiety-phobic reactions appeared at the age when emotional functions were not completely formed and might be considered as the presentations of emotional dysontogenesis. The authors assume that characteristics of fear expression in the early age allow to suspect a mental disease which might be timely diagnosed in case of its manifestation. The conclusions made in the paper may be useful for clinical practice of pediatricians, children neurologists, psychologists and psychiatrists.

  7. Signs of Early-stage Disk Growth Revealed with ALMA

    NASA Astrophysics Data System (ADS)

    Yen, Hsi-Wei; Koch, Patrick M.; Takakuwa, Shigehisa; Krasnopolsky, Ruben; Ohashi, Nagayoshi; Aso, Yusuke

    2017-01-01

    We present ALMA 1.3 mm continuum, 12CO, C18O, and SO data for the Class 0 protostars Lupus 3 MMS, IRAS 15398‑3559, and IRAS 16253‑2429 at resolutions of ∼100 au. By measuring a rotational profile in C18O, a 100 au Keplerian disk around a 0.3 M⊙ protostar is observed in Lupus 3 MMS. No 100 au Keplerian disks are observed in IRAS 15398‑3559 and IRAS 16253‑2429. Nevertheless, embedded compact (<30 au) continuum components are detected. The C18O emission in IRAS 15398‑3559 shows signatures of infall with a constant angular momentum. IRAS 16253‑2429 exhibits signatures of infall and rotation, but its rotational profile is unresolved. By fitting the C18O data with our kinematic models, the protostellar masses and the disk radii are inferred to be 0.01 M⊙ and 20 au in IRAS 15398‑3559, and 0.03 M⊙ and 6 au in IRAS 16253‑2429. By comparing the specific angular momentum profiles from 10,000 au to 100 au in eight Class 0 and I protostars, we find that the evolution of envelope rotation can be described with conventional inside-out collapse models. In comparison with a sample of 18 protostars with known disk radii, our results reveal signs of disk growth, with the disk radius increasing as {{M}* }0.8+/- 0.14 or {t}1.09+/- 0.37 in the Class 0 stage, where M* is the protostellar mass and t is the age. The disk growth rate slows down in the Class I stage. In addition, we find a hint that the mass accretion rate declines as {t}-0.26+/- 0.04 from the Class 0 to the Class I stages.

  8. Estramustine phosphate reversibly inhibits an early stage during adenovirus replication.

    PubMed

    Everitt, E; Ekstrand, H; Boberg, B; Hartley-Asp, B

    1990-01-01

    Estramustine phosphate, an estradiol-mustard conjugate, was shown to reversibly inhibit a stage during the first hour of productive adenovirus 2 infection of HeLa cells. This drug, employed in the therapy of advanced prostatic cancer, specifically interacts with microtubule-associated proteins (MAPs) of the cytoskeleton. The results obtained under physiological conditions in vivo suggest a MAPs-interference with the microtubule-mediated vectorial migration of the virus inoculum to the nucleus. Virus attachment, uncoating kinetics and the appearance of established uncoating intermediates were not affected.

  9. Features controlling the early stages of creep deformation of Waspaloy

    NASA Technical Reports Server (NTRS)

    Ferrari, A.; Wilson, D. J.

    1974-01-01

    A model has been presented for describing primary and second stage creep. General equations were derived for the amount and time of primary creep. It was shown how the model can be used to extrapolate creep data. Applicability of the model was demonstrated for Waspaloy with gamma prime particle sizes from 75 - 1000 A creep tested in the temperature range 1000 - 1400 F (538 - 760 C). Equations were developed showing the dependence of creep parameters on dislocation mechanism, gamma prime volume fraction and size.

  10. Screening of early antigen genes of adult-stage Trichinella spiralis using pig serum from different stages of early infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this work was to identify novel, early antigens present in Trichinella spiralis. To this end, a cDNA library generated from 3-day old adult worms (Ad3) was immunologically screened using serum from a pig infected with 20,000 muscle larvae. The serum was obtained from multiple, time cours...

  11. Formal Verification Toolkit for Requirements and Early Design Stages

    NASA Technical Reports Server (NTRS)

    Badger, Julia M.; Miller, Sheena Judson

    2011-01-01

    Efficient flight software development from natural language requirements needs an effective way to test designs earlier in the software design cycle. A method to automatically derive logical safety constraints and the design state space from natural language requirements is described. The constraints can then be checked using a logical consistency checker and also be used in a symbolic model checker to verify the early design of the system. This method was used to verify a hybrid control design for the suit ports on NASA Johnson Space Center's Space Exploration Vehicle against safety requirements.

  12. Fully compressible solutions for early stage Richtmyer–Meshkov instability

    SciTech Connect

    Margolin, Len G.; Reisner, Jon Michael

    2016-10-27

    Here, we will consider the effects of compressibility and viscosity on the early dynamics of the Richtmyer–Meshkov instability (RMI). In particular, we will combine theory, scaling, and high resolution simulation of RMI to probe the details of the initial compression and the subsequent viscous damping as a shock interacts with a density discontinuity. We will propose a refinement of the classic 1D model for the linear regime of RMI that, for small initial perturbation wavelengths, more accurately reproduces the 2D dynamics of a fully resolved numerical simulation.

  13. Collaboration with Pharma Will Introduce Nanotechnologies in Early Stage Drug Development | Poster

    Cancer.gov

    The Frederick National Lab has begun to assist several major pharmaceutical companies in adopting nanotechnologies in early stage drug development, when the approach is most efficient and cost-effective.

  14. [Predictive value of Ages & Stages Questionnaires for cognitive performance at early years of schooling].

    PubMed

    Schonhaut B, Luisa; Pérez R, Marcela; Castilla F, Ana María; Castro M, Sonia; Salinas A, Patricia; Armijo R, Iván

    2017-02-01

    The Ages and Stages questionnaires (ASQ) has been recently validated in our country for developmental screening. The objective of this study is evaluate the validity of ASQ to predict low cognitive performance in the early years of schooling.

  15. New NIA Booklet By and For People With Early-Stage Alzheimer's Disease

    MedlinePlus

    ... Booklet By and For People With Early-Stage Alzheimer's Disease Past Issues / Fall 2007 Table of Contents For ... you have a family member or friends with Alzheimer's disease? Are you wondering what they're going through ...

  16. Dutasteride May Slow the Growth of Early-Stage Prostate Cancer | Division of Cancer Prevention

    Cancer.gov

    For men who are undergoing active surveillance for early-stage prostate cancer, the drug dutasteride (Avodart) could help control the disease and prevent the need for more aggressive treatments. |

  17. Late Effects May Not Warrant Using Radiation to Treat Early-Stage Hodgkin Lymphoma

    Cancer.gov

    Patients with early-stage Hodgkin lymphoma who were treated with multidrug chemotherapy alone were more likely to be alive 12 years later than patients who received treatment that included radiation therapy, according to findings from a clinical trial.

  18. Analysis on Gene Expression Profile in Oncospheres and Early Stage Metacestodes from Echinococcus multilocularis

    PubMed Central

    Dang, Zhisheng; Suzuki, Yutaka; Horiuchi, Terumi; Yagi, Kinpei; Kouguchi, Hirokazu; Irie, Takao; Kim, Kyeongsoon; Oku, Yuzaburo

    2016-01-01

    Alveolar echinococcosis is a worldwide zoonosis of great public health concern. Analysis of genome data for Echinococcus multilocularis has identified antigen families that can be used in diagnostic assays and vaccine development. However, little gene expression data is available for antigens of the egg and early larval stages. To address this information gap, we used a Next-Generation Sequencing approach to investigate three different stages (non-activated and activated oncospheres, and early stage metacestodes) of E. multilocularis (Nemuro strain). Transcriptome data analysis revealed that some diagnostic antigen gp50 isoforms and the antigen Eg95 family dominated in activated oncospheres, and the antigen B family dominated in early stage metacestodes. Furthermore, heat shock proteins and antigen II/3 are constantly expressed in the three stages. The expression pattern of various known antigens in E. multilocularis may give fundamental information for choosing candidate genes used in diagnosis and vaccine development. PMID:27092774

  19. Staging Life in an Early Warm ‘Seltzer’ Ocean

    SciTech Connect

    Schoonen, Martin; Smirnov, Alexander

    2016-12-01

    A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO2 as well as N2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’ ocean. We used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.

  20. Staging Life in an Early Warm ‘Seltzer’ Ocean

    DOE PAGES

    Schoonen, Martin; Smirnov, Alexander

    2016-12-01

    A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO2 as well as N2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’ ocean. Wemore » used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.« less

  1. Problem solving, impulse control and planning in patients with early- and late-stage Huntington's disease.

    PubMed

    Mörkl, Sabrina; Müller, Nicole J; Blesl, Claudia; Wilkinson, Leonora; Tmava, Adelina; Wurm, Walter; Holl, Anna K; Painold, Annamaria

    2016-10-01

    Sub-domains of executive functions, including problems with planning, accuracy, impulsivity, and inhibition, are core features of Huntington's disease. It is known that the decline of cognitive function in Huntington's disease is related to the anatomical progression of pathology in the basal ganglia. However, it remains to be determined whether the severity of executive dysfunction depends on the stage of the disease. To examine the severity of sub-domains of executive dysfunction in early- and late-stage Huntington's disease, we studied performance in the Tower of London task of two groups of Huntington's disease patients (Group 1: early, n = 23, and Group 2: late stage, n = 29), as well as a third group of age, education, and IQ matched healthy controls (n = 34). During the task, we measured the total number of problems solved, total planning time, and total number of breaks taken. One aspect of executive function indexed by the number of solved problems seems to progress in the course of the disease. Late-stage Huntington's disease patients scored significantly worse than early-stage patients and controls, and early-stage patients scored significantly worse than controls on this measure of accuracy. In contrast, late- and early-stage HD patients did not differ in terms of planning time and number of breaks. Early- and late-stage HD pathology has a different impact on executive sub-domains. While accuracy differs between early- and late-stage HD patients, other domains like planning time and number of breaks do not. Striatal degeneration, which is a characteristic feature of the disease, might not affect all aspects of executive function in HD.

  2. Serum markers in early-stage and locally advanced melanoma.

    PubMed

    Lugowska, Iwona; Kowalska, Maria; Fuksiewicz, Małgorzata; Kotowicz, Beata; Mierzejewska, Ewa; Koseła-Paterczyk, Hanna; Szamotulska, Katarzyna; Rutkowski, Piotr

    2015-11-01

    The identification of prognostic factors in cutaneous melanoma allows choosing the most effective treatment, especially in group of patients with locoregional disease. Markers related to carcinogenesis and angiogenesis in particular have effect on the course of the disease. The aim of this study was to evaluate clinical utility of vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP-2), MMP-9, tissue inhibitors of metalloproteinase 1 (TIMP-1), and YKL-40 in serum of melanoma patients at pathological stages I-III. We included 148 adult patients with melanoma. The median follow-up was 40 months. Disease recurrence was observed in 43 patients; 3-year disease-free survival (DFS) rate was 71.7%; 35 patients died; and the 3-year overall survival (OS) rate was 85%. Concentrations of VEGF, MMP-2, MMP-9, TIMP-1, and YKL-40 were measured by ELISA kits. VEGF, MMP-9, TIMP-1, and YKL-40 were significantly higher in group of patients than in controls. Increased concentrations of TIMP-1 were related to patient survival, which in the group of lower and increased TIMP-1, disease-free survival amounted to 81 vs. 61% (p = 0.014) and overall survival -88 vs. 82% (p = 0.050), respectively. An increased concentration of YKL-40 was observed in 59% of patients with ulceration and in 26% of patients without ulceration (p = 0.012). We have found a clinically significant correlation between YKL-40 and MMP-9 (rho = 0.363; p = 0.004) as well as YKL-40 and VEGF (rho = 0.306; p = 0.018). In melanoma patients at stages I-III, the high concentrations of TIMP-1 in serum predicted adverse prognosis. YKL-40 was associated with ulceration of primary tumor, which is a very important prognostic factor.

  3. Upper thermal tolerances of early life stages of freshwater mussels

    USGS Publications Warehouse

    Pandolfo, Tamara J.; Cope, W. Gregory; Arellano, Consuelo; Bringolf, Robert B.; Barnhart, M. Christopher; Hammer, E

    2010-01-01

    Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata,Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also were tested as juveniles. Survival trends were monitored while mussels held at 3 acclimation temperatures (17, 22, and 27°C) were exposed to a range of common and extreme water temperatures (20–42°C) in standard acute laboratory tests. The average median lethal temperature (LT50) among species in 24-h tests with glochidia was 31.6°C and ranged from 21.4 to 42.7°C. The mean LT50 in 96-h juvenile tests was 34.7°C and ranged from 32.5 to 38.8°C. Based on comparisons of LT50s, thermal tolerances differed among species for glochidia, but not for juveniles. Acclimation temperature did not affect thermal tolerance for either life stage. Our results indicate that freshwater mussels already might be living close to their upper thermal tolerances in some systems and, thus, might be at risk from rising environmental temperatures.

  4. Microbial Diversity within Early-Stage Cultured Panulirus ornatus Phyllosomas▿

    PubMed Central

    Payne, Matthew S.; Hall, Mike R.; Sly, Lindsay; Bourne, David G.

    2007-01-01

    A thorough understanding of the microorganisms and pathogens associated with the larval stage of the tropical ornate rock lobster, Panulirus ornatus, is required to overcome disease outbreaks that currently block aquaculture attempts. This study used microscopy in addition to culture and molecularly based microbiological techniques to characterize the bacterial community associated with cultured, developmental stage PI to PII P. ornatus phyllosomas. Scanning electron microscopy demonstrated colonization of phyllosomas by filamentous, rod-shaped, and coccus-shaped bacteria. A clone library constructed from dead phyllosomas sampled from the larval rearing tank on day 10 was dominated by Thiothrix-affiliated sequences (56% of clones). A comparable library from live phyllosomas also contained Thiothrix-affiliated sequences, though these only represented 19% of clones within the library. Fluorescent in situ hybridization (FISH) confirmed identification of the filamentous bacteria as Thiothrix sp., being present on dead phyllosomas. FISH also identified Leucothrix sp. and Vibrio sp., as well as a range of other rod- and coccus-shaped bacteria, colonizing both live and dead phyllosomas. The development of the microbial community associated with phyllosomas was monitored through a standard larval rearing run using denaturing gradient gel electrophoresis (DGGE). Vibrio sp.-affiliated bands dominated the profiles of live animals through the rearing period and dead phyllosomas sampled on selected days. The population of Vibrio sp. associated with phyllosomas was monitored with culture-based analysis on selective media and demonstrated to increase significantly on day 7, coinciding with the beginning of the larval molt. An isolated Vibrio harveyi strain demonstrated an identical 16S rRNA sequence with retrieved DGGE and clone library sequences. Colonization of phyllosomas with filamentous bacterial species potentially hinders the ability of the animals to molt and, combined

  5. Shipboard Electrical System Modeling for Early-Stage Design Space Exploration

    DTIC Science & Technology

    2013-04-01

    Shipboard Electrical System Modeling for Early -Stage Design Space Exploration Aaron M. Cramer, Hanling Chen Department of Electrical and Computer...Department United States Naval Academy Annapolis, MD, USA Email: zivi@usna.edu Abstract—In early -stage design exploration, it has been found that...involved the use of linear programming to model the action of the power system [6]. In this approach, the mechanical dynamics associated with prime movers

  6. Alternatives to surgery in early stage disease—stereotactic body radiotherapy

    PubMed Central

    Giuliani, Meredith Elana

    2013-01-01

    The management of early stage non-small cell lung carcinoma (NSCLC) has been revolutionized by the introduction of stereotactic body radiotherapy (SBRT). SBRT is now the standard of care for medically inoperable patients with early stage NSCLC. However, the role of SBRT in medically operable patients remains controversial. This article will review the indications, the technical considerations, image guidance principles, potential toxicities and special circumstances in lung SBRT. PMID:25806252

  7. Identification of a Genomic Signature Predicting for Recurrence in Early Stage Ovarian Cancer

    DTIC Science & Technology

    2014-10-01

    Award Number: W81XWH-12-1-0521 TITLE: Identification of a Genomic Signature Predicting for Recurrence in Early Stage Ovarian Cancer PRINCIPAL...SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0521 Identification of a Genomic Signature Predicting for Recurrence in Early-Stage...clinical annotation and accurate pathological review (228 recurrent and 364 non-recurrent), 2) established a specimen repository and clinical data

  8. Confidence Interval Estimation for Sensitivity to the Early Diseased Stage Based on Empirical Likelihood.

    PubMed

    Dong, Tuochuan; Tian, Lili

    2015-01-01

    Many disease processes can be divided into three stages: the non-diseased stage: the early diseased stage, and the fully diseased stage. To assess the accuracy of diagnostic tests for such diseases, various summary indexes have been proposed, such as volume under the surface (VUS), partial volume under the surface (PVUS), and the sensitivity to the early diseased stage given specificity and the sensitivity to the fully diseased stage (P2). This paper focuses on confidence interval estimation for P2 based on empirical likelihood. Simulation studies are carried out to assess the performance of the new methods compared to the existing parametric and nonparametric ones. A real dataset from Alzheimer's Disease Neuroimaging Initiative (ADNI) is analyzed.

  9. Developmental rate and behavior of early life stages of bighead carp and silver carp

    USGS Publications Warehouse

    Chapman, Duane C.; George, Amy E.

    2011-01-01

    The early life stages of Asian carp are well described by Yi and others (1988), but since these descriptions are represented by line drawings based only on live individuals and lacked temperature controls, further information on developmental time and stages is of use to expand understanding of early life stages of these species. Bighead carp and silver carp were cultured under two different temperature treatments to the one-chamber gas bladder stage, and a photographic guide is provided for bighead carp and silver carp embryonic and larval development, including notes about egg morphology and larval swimming behavior. Preliminary information on developmental time and hourly thermal units for each stage is also provided. Both carp species developed faster under warmer conditions. Developmental stages and behaviors are generally consistent with earlier works with the exception that strong vertical swimming immediately after hatching was documented in this report.

  10. Hydrogenation of iron in the early stage of Earth's evolution

    PubMed Central

    Iizuka-Oku, Riko; Yagi, Takehiko; Gotou, Hirotada; Okuchi, Takuo; Hattori, Takanori; Sano-Furukawa, Asami

    2017-01-01

    Density of the Earth's core is lower than that of pure iron and the light element(s) in the core is a long-standing problem. Hydrogen is the most abundant element in the solar system and thus one of the important candidates. However, the dissolution process of hydrogen into iron remained unclear. Here we carry out high-pressure and high-temperature in situ neutron diffraction experiments and clarify that when the mixture of iron and hydrous minerals are heated, iron is hydrogenized soon after the hydrous mineral is dehydrated. This implies that early in the Earth's evolution, as the accumulated primordial material became hotter, the dissolution of hydrogen into iron occurred before any other materials melted. This suggests that hydrogen is likely the first light element dissolved into iron during the Earth's evolution and it may affect the behaviour of the other light elements in the later processes. PMID:28082735

  11. Detecting early stage osteoarthritis by optical coherence tomography?

    PubMed Central

    Jahr, Holger; Brill, Nicolai; Nebelung, Sven

    2015-01-01

    Abstract Osteoarthritis (OA) is the most common chronic disease of our joints, manifested by a dynamically increasing degeneration of hyaline articular cartilage (AC). While currently no therapy can reverse this process, the few available treatment options are hampered by the inability of early diagnosis. Loss of cartilage surface, or extracellular matrix (ECM), integrity is considered the earliest sign of OA. Despite the increasing number of imaging modalities surprisingly few imaging biomarkers exist. In this narrative review, recent developments in optical coherence tomography are critically evaluated for their potential to assess different aspects of AC quality as biomarkers of OA. Special attention is paid to imaging surface irregularities, ECM organization and the evaluation of posttraumatic injuries by light-based modalities. PMID:26862954

  12. Hydrogenation of iron in the early stage of Earth's evolution

    NASA Astrophysics Data System (ADS)

    Iizuka-Oku, Riko; Yagi, Takehiko; Gotou, Hirotada; Okuchi, Takuo; Hattori, Takanori; Sano-Furukawa, Asami

    2017-01-01

    Density of the Earth's core is lower than that of pure iron and the light element(s) in the core is a long-standing problem. Hydrogen is the most abundant element in the solar system and thus one of the important candidates. However, the dissolution process of hydrogen into iron remained unclear. Here we carry out high-pressure and high-temperature in situ neutron diffraction experiments and clarify that when the mixture of iron and hydrous minerals are heated, iron is hydrogenized soon after the hydrous mineral is dehydrated. This implies that early in the Earth's evolution, as the accumulated primordial material became hotter, the dissolution of hydrogen into iron occurred before any other materials melted. This suggests that hydrogen is likely the first light element dissolved into iron during the Earth's evolution and it may affect the behaviour of the other light elements in the later processes.

  13. Familiarity and Emotional Expression Influence an Early Stage of Face Processing: An Electrophysiological Study

    ERIC Educational Resources Information Center

    Caharel, Stephanie; Courtay, Nolwenn; Bernard, Christian; Lalonde, Robert; Rebai, Mohamed

    2005-01-01

    Recent data indicate that the familiarity and the emotional expression of faces occur at an early stage of information processing. The goal of the present study was to determine whether these two aspects interact at the structural encoding stage as reflected by the N170 component of event-related potentials in tasks requiring the subjects either…

  14. The Serum Glycome to Discriminate between Early-Stage Epithelial Ovarian Cancer and Benign Ovarian Diseases

    PubMed Central

    Braicu, Elena Iona; Sehouli, Jalid; Tauber, Rudolf; Blanchard, Véronique

    2014-01-01

    Epithelial ovarian cancer (EOC) is the sixth most common cause of cancer deaths in women because the diagnosis occurs mostly when the disease is in its late-stage. Current diagnostic methods of EOC show only a moderate sensitivity, especially at an early-stage of the disease; hence, novel biomarkers are needed to improve the diagnosis. We recently reported that serum glycome modifications observed in late-stage EOC patients by MALDI-TOF-MS could be combined as a glycan score named GLYCOV that was calculated from the relative areas of the 11 N-glycan structures that were significantly modulated. Here, we evaluated the ability of GLYCOV to recognize early-stage EOC in a cohort of 73 individuals comprised of 20 early-stage primary serous EOC, 20 benign ovarian diseases (BOD), and 33 age-matched healthy controls. GLYCOV was able to recognize stage I EOC whereas CA125 values were statistically significant only for stage II EOC patients. In addition, GLYCOV was more sensitive and specific compared to CA125 in distinguishing early-stage EOC from BOD patients, which is of high relevance to clinicians as it is difficult for them to diagnose malignancy prior to operation. PMID:25183900

  15. Using rangeland health assessment to inform successional management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in ...

  16. OLD FIELD SUCCESSIONAL DYNAMICS FOLLOWING CESSATION OF CHRONIC DISTURBANCE

    EPA Science Inventory

    In grasslands dominated by warm-season grasses, community composition and successional patterns can be altered by disturbance and exotic species invasions. Our objective was to describe vegetation dynamics following cessation of a chronic disturbance (heavy grazing by cattle) in...

  17. Advancing Early Detection of Autism Spectrum Disorder by Applying an Integrated Two-Stage Screening Approach

    ERIC Educational Resources Information Center

    Oosterling, Iris J.; Wensing, Michel; Swinkels, Sophie H.; van der Gaag, Rutger Jan; Visser, Janne C.; Woudenberg, Tim; Minderaa, Ruud; Steenhuis, Mark-Peter; Buitelaar, Jan K.

    2010-01-01

    Background: Few field trials exist on the impact of implementing guidelines for the early detection of autism spectrum disorders (ASD). The aims of the present study were to develop and evaluate a clinically relevant integrated early detection programme based on the two-stage screening approach of Filipek et al. (1999), and to expand the evidence…

  18. Dyadic Intervention for Family Caregivers and Care Receivers in Early-Stage Dementia

    ERIC Educational Resources Information Center

    Whitlatch, Carol J.; Judge, Katherine; Zarit, Steven H.; Femia, Elia

    2006-01-01

    Purpose: The Early Diagnosis Dyadic Intervention (EDDI) program provides a structured, time-limited protocol of one-on-one and dyadic counseling for family caregivers and care receivers who are in the early stages of dementia. The goals and procedures of EDDI are based on previous research suggesting that dyads would benefit from an intervention…

  19. Involvement of lysosomes in the early stages of axon degeneration.

    PubMed

    Zheng, Jin; Yan, Tingting; Feng, Yan; Zhai, Qiwei

    2010-02-01

    Axon degeneration is a common hallmark of many neurodegenerative diseases, and the underlying mechanism remains largely unknown. Lysosomes are involved in some neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Whether lysosomes are involved in axon degeneration is yet to be elucidated. In this study, we found only about 10% lysosomes remained in axons of cultured superior cervical ganglia (SCGs) after transection for 4h when stained with LysoTracker. Furthermore, we found that lysosomal disruption occurred earlier than morphological changes and loss of mitochondrial membrane potential. In addition, the well-known axon-protective protein Wld(S) delayed injury-induced axon degeneration from both morphological changes and lysosomal disruption. Lysosomal inhibitors including chloroquine and ammonium chloride induced axon degeneration in cultured SCGs, and Wld(S) also slowed down the axon degeneration induced by lysosomal inhibitors. All these data suggest that lysosomal disruption is an early marker of axon degeneration, and inhibition of lysosome induces axon degeneration in a Wld(S)-protectable way. Thus, maintenance of normal lysosomal function might be an important approach to delay axon degeneration in neurodegenerative diseases.

  20. Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes.

    PubMed

    Tautenhahn, Susanne; Lichstein, Jeremy W; Jung, Martin; Kattge, Jens; Bohlman, Stephanie A; Heilmeier, Hermann; Prokushkin, Anatoly; Kahl, Anja; Wirth, Christian

    2016-06-01

    Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods

  1. Litterfall production along successional and altitudinal gradients of subtropical monsoon evergreen broadleaved forests in Guangdong, China

    USGS Publications Warehouse

    Zhou, G.; Guan, L.; Wei, X.; Zhang, Dongxiao; Zhang, Q.; Yan, J.; Wen, D.; Liu, J.; Liu, S.; Huang, Z.; Kong, G.; Mo, J.; Yu, Q.

    2007-01-01

    Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982-2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m-2 for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m-2 for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study. ?? 2006 Springer Science+Business Media B.V.

  2. Successional Distance between the Source and Recipient Influence Seed Germination and Seedling Survival during Surface Soil Replacement in SW China

    PubMed Central

    Shen, You-xin; Gao, Lei; Xia, Xue; Li, Yuhui; Guan, Huilin

    2013-01-01

    Adding propagules (source) to a degraded site (recipient) is a common way of manipulating secondary succession to restore diversity and services formerly provided by forests. However, heretofore no study has considered the effect of “successional distance” between source and recipient site. Four sites in the Shilin karst area of SW China were treated as different states along a secondary successional sere: grass, shrub, young secondary forest, and primary forest. Ten 1 m ×1m soil quadrats in the grass, shrub and young forest sites were replaced with 10 cm deep soil sources from corresponding later successional stage(s) in January 2009. Woody plant seed germination was monitored in the first year and seedling survival was monitored until the end of the second year. At the end of 2010, 2097 seeds of woody plants belonging to 45 taxa had germinated, and 3.9% of the seedlings and 7.8% of the species survived. Germination of most species was sensitive to ambient light (red, far-red, R:FR ratios, photosynthetically active radiation). Soil source and recipient site had a significant effect on the total number of seeds and number of species that germinated, and on the percentage of seedlings that survived through the end of the second year. Closer successional stages between recipient site and soil source had higher seed germination and seedling-survival percentages. However, a transition threshold exists in the young forest state, where seeds can germinate but not survive the second year. Our results, although based on an unreplicated chronosequence, suggest that successional distance between soil sources and recipient sites affect forest recruitment and restoration in degraded karst of SW China. PMID:24223891

  3. Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV infection

    DTIC Science & Technology

    1988-05-01

    FRONT COVER FUNDING NO. 87PP7875 S L. TITLE: Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV Infection PRINCIPAL INVESTIGATOR...Prospective Double-Blind Study of Zidovudine (AZT) in Early State HIV Infection 12. PERSONAL AUTHOR(S) Shannon M. Harrison 13a. TYPE OF REPORT 113b...COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUBGROUP HIV , Zidovudine, Early, Infection 06

  4. Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish.

    PubMed

    Ingley, Spencer J; Johnson, Jerald B

    2016-03-01

    How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time.

  5. Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish

    PubMed Central

    Johnson, Jerald B.

    2016-01-01

    How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time. PMID:26979559

  6. Formation of Jupiter's Core and Early Stages of Envelope Accretion

    NASA Astrophysics Data System (ADS)

    D'Angelo, G.; Weidenschilling, S.; Lissauer, J. J.; Bodenheimer, P.; Hubickyj, O.

    2012-12-01

    We are performing calculations of the formation of Jupiter via core nucleated accretion and gas capture. The core starts as a seed body of a few hundred kilometers in radius and orbits within a swarm of planetesimals whose initial size distribution ranges from ~10 m to ~100 km. The planetesimals are immersed in a gaseous disk, representative of an early solar nebula. The evolution of the swarm of planetesimals accounts for collisions and gravitational stirring due to mutual interactions among bodies, and for migration and velocity damping due to interactions with the nebula gas. Collisions among planetesimals lead to growth and/or fragmentation, altering the size distribution of the swarm over time. Collisions of planetesimals with the seed body lead to its growth, resulting in the formation of a planetary core. Gas capture by the core leads to the accumulation of a tenuous atmosphere, which later becomes a massive envelope, increasing the size-dependent effective cross-section of the planet for planetesimals' accretion. Planetesimals that travel through the core's envelope release energy, affecting the thermal budget of the envelope, and deliver mass, affecting the opacity of the envelope. The calculation of dust opacity, which is especially important for envelope contraction, is performed self-consistently, accounting for coagulation and sedimentation of dust and small particles that are released in the envelope as passing planetesimals are ablated. We find that, in a disk of planetesimals with a surface density of about 10 g/cm2 at 5.2 AU, a one Earth mass core accumulates in less than 1e5 years, and that it takes over 1.5e6 years to accumulate a core of 3 Earth masses, when the core's geometrical cross-section is used for the accretion of planetesimals. Gas drag in the core's envelope increases the ability of the planet to accrete planetesimals. Smaller planetesimals are affected to a greater extent than are larger planetesimals. We find that the effective

  7. The Memory Club: Providing support to persons with early-stage dementia and their care partners.

    PubMed

    Gaugler, Joseph E; Gallagher-Winker, Karen; Kehrberg, Kathy; Lunde, Angela M; Marsolek, Connie M; Ringham, Kathryn; Thompson, Gerise; Barclay, Michelle

    2011-05-01

    There is a growing emphasis on delivering services for persons with early-stage dementia (ie, ''persons with memory loss,'' or PWMLs) and their family members (care partners). The goal of this evaluation was to determine whether participation in the Memory Club, a 10- to 13-session joint support group, would result in decreased distress, enhanced preparation for care, and improved feelings of confidence managing the challenges of early-stage dementia. The single group, pre-/post-test evaluation included 63 PWMLs and 61 care partners who participated in three Memory Club sites in Minnesota. Paired T-test results found that care partners reported significant (P < .05) increases in preparation activities, feelings of preparation, and confidence in managing memory loss. The results suggest that the Memory Club can fill an important gap in early-stage dementia care by offering care partners the opportunity to plan, prepare, and increase coping skills in the face of early dementia progression.

  8. Integrative Protein-Based Prognostic Model for Early Stage Endometrioid Endometrial Cancer

    PubMed Central

    Yang, Ji-Yeon; Werner, Henrica M.J.; Li, Jie; Westin, Shannon N.; Lu, Yiling; Halle, Mari K.; Trovik, Jone; Salvesen, Helga B.; Mills, Gordon B.; Liang, Han

    2015-01-01

    Purpose Endometrioid endometrial carcinoma (EEC) is the major histological type of endometrial cancer, the most prevalent gynecologic malignancy in USA. EEC recurrence or metastasis is associated with a poor prognosis. Early-stage EEC is generally curable, but a subset has high risk of recurrence or metastasis. Prognosis estimation for early-stage EEC mainly relies on clinicopathological characteristics, but is unreliable. We aimed to identify patients with high-risk early-stage EEC who are most likely to benefit from more extensive surgery and adjuvant therapy by building a prognostic model that integrates clinical variables and protein markers. Experimental Design We employed two large, independent early-stage EEC datasets as training (n = 183) and validation cohorts (n = 333), and generated the levels of 186 proteins and phosphoproteins using reverse-phase protein arrays. By applying an initial filtering and the elastic net to the training samples, we developed a prognostic model for overall survival containing two clinical variables and 18 protein markers and optimized the risk group classification. Results Kaplan-Meier survival analyses in the validation cohort confirmed an improved discriminating power of our prognostic model for patients with early-stage EEC over key clinical variables (log-rank test p-value = 0.565 for disease stage, 0.567 for tumor grade, 1.3×10−4 for the integrative model). Compared with clinical variables (stage, grade, and patient age), only the risk groups defined by the integrative model were consistently significant in both univariate and multivariate analyses across both cohorts. Conclusions Our prognostic model is potentially of high clinical value for stratifying patients with early-stage EEC and improving their treatment strategies. PMID:26224872

  9. Driving behaviors in early stage dementia: a study using in-vehicle technology.

    PubMed

    Eby, David W; Silverstein, Nina M; Molnar, Lisa J; LeBlanc, David; Adler, Geri

    2012-11-01

    According to the Alzheimer's Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimer's disease in the United States (US). There is evidence that drivers with Alzheimer's disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1-2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.

  10. Comparison of Laparoscopy and Laparotomy in Surgical Staging of Apparent Early Ovarian Cancer

    PubMed Central

    Lu, Qi; Qu, Hong; Liu, Chongdong; Wang, Shuzhen; Zhang, Zhiqiang; Zhang, Zhenyu

    2016-01-01

    Abstract The aim of this study was to compare the safety and morbidity of laparoscopic versus laparotomic comprehensive staging of apparent early stage ovarian cancer. In this retrospective study, the outcomes of patients with apparent stage I ovarian cancer who underwent laparoscopic or laparotomic comprehensive surgical staging from January 2002 to January 2014 were evaluated. The long-term survival of patients with early ovarian cancer was compared. Forty-two patients were treated by laparoscopy, and 50 were treated by laparotomy. The median operative time was 200 minutes in the laparoscopy group and 240 minutes in the laparotomy group (P >0.05). The median length of hospital stay was 3 days in the laparoscopy group and 7 days in the laparotomy group (P <0.05). Following laparoscopic and laparotomic staging, the cancer was upstaged for 9 (21.4%) and 10 (20.0%) women, respectively. The median follow-up time was 82 months in the laparoscopic and laparotomic groups, respectively. Excluding the upstaged patients, no recurrence was observed in the present study, and the overall survival and 5-year survival rates were 100% in both the laparoscopy and laparotomy groups. Laparoscopic and laparotomic comprehensive staging of early ovarian cancer were similar in terms of staging adequacy, accuracy and survival rate. Laparoscopic staging was associated with a significantly reduced hospital stay. Prospective randomized trials are required to evaluate the overall oncologic outcomes. PMID:27196468

  11. Alternatives to the fish early life-stage test: Developing a conceptual model for early fish development

    EPA Science Inventory

    Chronic fish toxicity is a key parameter for hazard classification and environmental risk assessment of chemicals, and the OECD 210 fish early life-stage (FELS) test is the primary guideline test used for various international regulatory programs. There exists a need to develop ...

  12. Transvaginal Sonography Versus Cystoscopy for Detecting Urinary Bladder Invasion in Early Stage Cervical Cancer

    PubMed Central

    Zutshi, Vijay; Garg, Anju; Batra, Swaraj

    2017-01-01

    Introduction Cervical cancer is a major cause of mortality from cancer among women. In it’s early stage pre operative staging with cystoscopy is a standard procedure for the detection of urinary bladder involvement. Aim The present study was conducted with the aim to compare the efficacy of Transvaginal Sonography (TVS) and cystoscopy in diagnosing bladder involvement in early stage cervical cancer patients by confirming it intraoperatively and further by histopathologic examination. Materials and Methods A prospective partially blinded study was conducted between March 2006 and September 2008 on 30 patients with early stage cervical cancer (Stage I and IIa) who were planned to undergo radical hysterectomy. Pre operatively, these patients underwent both TVS and cystoscopy to diagnose bladder involvement. Presence or absence of bladder involvement was then confirmed intra operatively and by histopathologic examination. Results In all the 30 patients studied, no bladder involvement was seen on cystoscopy where as TVS showed bladder involvement in three patients. Involvement of the bladder in these three patients was confirmed intra operatively and by histopathologic examination. Thus, in our study, TVS was 100% sensitive in detecting bladder involvement. Conclusion TVS is highly sensitive in diagnosing bladder involvement in early stage cervical cancer and could potentially detect cases missed with a cystoscopy.

  13. All-optical photoacoustic imaging and detection of early-stage dental caries

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin; Hughes, David A.; Longbottom, Chris; Kirk, Katherine J.

    2015-02-01

    Dental caries remain one of the most common oral diseases in the world. Current detection methods, such as dental explorer and X-ray radiography, suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease because of the small size (< 100 microns) of early-stage lesions. We have developed a fine-resolution (480 nm), ultra-broadband (1 GHz), all-optical photoacoustic imaging (AOPAI) system to image and detect early stages of tooth decay. This AOPAI system provides a non-contact, non-invasive and non-ionizing means of detecting early-stage dental caries. Ex-vivo teeth exhibiting early-stage, white-spot lesions were imaged using AOPAI. Experimental scans targeted each early-stage lesion and a reference healthy enamel region. Photoacoustic (PA) signals were generated in the tooth using a 532-nm pulsed laser and the light-induced broadband ultrasound signal was detected at the surface of the tooth with an optical path-stabilized Michelson interferometer operating at 532 nm. The measured time-domain signal was spatially resolved and back-projected to form 2D and 3D maps of the lesion using k-wave reconstruction methods. Experimental data collected from areas of healthy and diseased enamel indicate that the lesion generated a larger PA response compared to healthy enamel. The PA-signal amplitude alone was able to detect a lesion on the surface of the tooth. However, time- reversal reconstructions of the PA scans also quantitatively depicted the depth of the lesion. 3D PA reconstruction of the diseased tooth indicated a sub-surface lesion at a depth of 0.6 mm, in addition to the surface lesion. These results suggest that our AOPAI system is well suited for rapid clinical assessment of early-stage dental caries. An overview of the AOPAI system, fine-resolution PA and histology results of diseased and healthy teeth will be presented.

  14. Successional change in photosynthetic capacities after wildfires across the North American boreal forests

    NASA Astrophysics Data System (ADS)

    Tahara, N.; Ueyama, M.; Iwata, H.; Ichii, K.; Harazono, Y.; Nagano, H.

    2015-12-01

    Wildfire is a major disturbance across the North American boreal forests. Canopy ecophysiology is important to understand recovery of carbon dioxide and water vapor fluxes after wildfires. We developed a big-leaf model coupled photosynthesis (Farquhar et al., 1980) and stomatal conductance (Ball et al., 1987) models. We inputted eddy covariance data from fire chronosequence across the North American boreal forests into the big-leaf model for optimizing parameters: maximum carboxylation rate at 25℃ (Vcmax25) and stomatal conductance parameters. The model was optimized with a global optimization technique: SCE-UA method (Duan et al., 1994). The estimated canopy-scale parameters were then downscaled into a leaf scale (vcmax25; values per sun leaf area) using a two-leaf radiation transfer model (de Pury and Farquhar, 1997) and leaf area index. We used 6 sites from two fire chronosequence in Alaska (1~, 3~, 5~, 15~ and 80~ years after fire; Liu et al., 2005; Iwata et al., 2011) and 6 sites from a Canadian chronosequence study (6~, 15~, 23~, 40~ and 74~ years after fire; Goulden et al., 2010). Preliminary results showed clear seasonal variations in canopy-scale Vcmax25 with the maximum during the summer. In Alaska, the downscaled vcmax25 for four years after fire exceeded those of mature forests, indicating that the photosynthetic capacity recovered quickly in the early successional stage. This quick recovery was not seen in gross primary productivity. We will show the variations of the ecophysiological parameters in terms of environment conditions and stand age. References Ball et al., 1987: In Progress in Photosynthesis Research, 221-224. de Pury and Farquhar, 1997: Plant, Cell and Environ., 20, 537-557. Duan et al., 1994: J. Hydrology, 158, 265-284. Farquhar et al., 1980: Planta, 149, 78-90. Goulden et al., 2010: Global Change Biol., 17, 855-871. Iwata et al., 2011: SOLA., 7, 105-108. Liu et al., 2005: J. Geophys. Res., 110, D13101.

  15. Rain forest fragmentation and the proliferation of successional trees.

    PubMed

    Laurance, William F; Nascimento, Henrique E M; Laurance, Susan G; Andrade, Ana C; Fearnside, Philip M; Ribeiro, José E L; Capretz, Robson L

    2006-02-01

    The effects of habitat fragmentation on diverse tropical tree communities are poorly understood. Over a 20-year period we monitored the density of 52 tree species in nine predominantly successional genera (Annona, Bellucia, Cecropia, Croton, Goupia, Jacaranda, Miconia, Pourouma, Vismia) in fragmented and continuous Amazonian forests. We also evaluated the relative importance of soil, topographic, forest dynamic, and landscape variables in explaining the abundance and species composition of successional trees. Data were collected within 66 permanent 1-ha plots within a large (approximately 1000 km2) experimental landscape, with forest fragments ranging from 1 to 100 ha in area. Prior to forest fragmentation, successional trees were uncommon, typically comprising 2-3% of all trees (> or =10 cm diameter at breast height [1.3 m above the ground surface]) in each plot. Following fragmentation, the density and basal area of successional trees increased rapidly. By 13-17 years after fragmentation, successional trees had tripled in abundance in fragment and edge plots and constituted more than a quarter of all trees in some plots. Fragment age had strong, positive effects on the density and basal area of successional trees, with no indication of a plateau in these variables, suggesting that successional species could become even more abundant in fragments over time. Nonetheless, the 52 species differed greatly in their responses to fragmentation and forest edges. Some disturbance-favoring pioneers (e.g., Cecropia sciadophylla, Vismia guianensis, V. amazonica, V. bemerguii, Miconia cf. crassinervia) increased by >1000% in density on edge plots, whereas over a third (19 of 52) of all species remained constant or declined in numbers. Species responses to fragmentation were effectively predicted by their median growth rate in nearby intact forest, suggesting that faster-growing species have a strong advantage in forest fragments. An ordination analysis revealed three main

  16. Using Spirituality to Cope with Early Stage Alzheimer’s disease

    PubMed Central

    Grando, Victoria T.

    2010-01-01

    Alzheimer’s disease (AD) robs persons living with this disease of their independence and self-esteem, which can lead to depression, anxiety, and loneliness. Understanding how people with early stage AD cope is a critical step to enhance their adaptive abilities and ultimately improve their quality of life. This qualitative study describes how individuals with early stage AD use spirituality to cope with the losses of self-esteem, independence, and social interaction that they face. The purposive sample for this focused ethnography study consisted of 15 participants living at home in central Arkansas. Holding onto faith, seeking reassurance and hope, and staying connected were the global themes. Personal faith, prayer, connection to church, and family support enhanced the ability for people with early stage AD to keep a positive attitude as they face living with Alzheimer’s. PMID:19282270

  17. Optimal adaptive two-stage designs for early phase II clinical trials.

    PubMed

    Shan, Guogen; Wilding, Gregory E; Hutson, Alan D; Gerstenberger, Shawn

    2016-04-15

    Simon's optimal two-stage design has been widely used in early phase clinical trials for Oncology and AIDS studies with binary endpoints. With this approach, the second-stage sample size is fixed when the trial passes the first stage with sufficient activity. Adaptive designs, such as those due to Banerjee and Tsiatis (2006) and Englert and Kieser (2013), are flexible in the sense that the second-stage sample size depends on the response from the first stage, and these designs are often seen to reduce the expected sample size under the null hypothesis as compared with Simon's approach. An unappealing trait of the existing designs is that they are not associated with a second-stage sample size, which is a non-increasing function of the first-stage response rate. In this paper, an efficient intelligent process, the branch-and-bound algorithm, is used in extensively searching for the optimal adaptive design with the smallest expected sample size under the null, while the type I and II error rates are maintained and the aforementioned monotonicity characteristic is respected. The proposed optimal design is observed to have smaller expected sample sizes compared to Simon's optimal design, and the maximum total sample size of the proposed adaptive design is very close to that from Simon's method. The proposed optimal adaptive two-stage design is recommended for use in practice to improve the flexibility and efficiency of early phase therapeutic development.

  18. Identification of Early-Stage Alzheimer's Disease Using Sulcal Morphology and Other Common Neuroimaging Indices

    PubMed Central

    Cai, Kunpeng; Xu, Hong; Guan, Hao; Zhu, Wanlin; Jiang, Jiyang; Cui, Yue; Zhang, Jicong; Liu, Tao; Wen, Wei

    2017-01-01

    Identifying Alzheimer’s disease (AD) at its early stage is of major interest in AD research. Previous studies have suggested that abnormalities in regional sulcal width and global sulcal index (g-SI) are characteristics of patients with early-stage AD. In this study, we investigated sulcal width and three other common neuroimaging morphological measures (cortical thickness, cortical volume, and subcortical volume) to identify early-stage AD. These measures were evaluated in 150 participants, including 75 normal controls (NC) and 75 patients with early-stage AD. The global sulcal index (g-SI) and the width of five individual sulci (the superior frontal, intra-parietal, superior temporal, central, and Sylvian fissure) were extracted from 3D T1-weighted images. The discriminative performances of the other three traditional neuroimaging morphological measures were also examined. Information Gain (IG) was used to select a subset of features to provide significant information for separating NC and early-stage AD subjects. Based on the four modalities of the individual measures, i.e., sulcal measures, cortical thickness, cortical volume, subcortical volume, and combinations of these individual measures, three types of classifiers (Naïve Bayes, Logistic Regression and Support Vector Machine) were applied to compare the classification performances. We observed that sulcal measures were either superior than or equal to the other measures used for classification. Specifically, the g-SI and the width of the Sylvian fissure were two of the most sensitive sulcal measures and could be useful neuroanatomical markers for detecting early-stage AD. There were no significant differences between the three classifiers that we tested when using the same neuroanatomical features. PMID:28129351

  19. Repeated burning of eastern tallgrass prairie increases richness and diversity, stabilizing late successional vegetation.

    PubMed

    Bowles, Marlin L; Jones, Michael D

    2013-03-01

    Understanding temporal effects of fire frequency on plant species diversity and vegetation structure is critical for managing tallgrass prairie (TGP), which occupies a mid-continental longitudinal precipitation and productivity gradient. Eastern TGP has contributed little information toward understanding whether vegetation-fire interactions are uniform or change across this biome. We resampled 34 fire-managed mid- and late-successional ungrazed TGP remnants occurring across a dry to wet-mesic moisture gradient in the Chicago region of Illinois, USA. We compared hypotheses that burning acts either as a stabilizing force or causes change in diversity and structure, depending upon fire frequency and successional stage. Based on western TGP, we expected a unimodal species richness distribution across a cover-productivity gradient, variable functional group responses to fire frequency, and a negative relationship between fire frequency and species richness. Species diversity was unimodal across the cover gradient and was more strongly humpbacked in stands with greater fire frequency. In support of a stabilizing hypothesis, temporal similarity of late-successional vegetation had a logarithmic relationship with increasing fire frequency, while richness and evenness remained stable. Temporal similarity within mid-successional stands was not correlated with fire frequency, while richness increased and evenness decreased over time. Functional group responses to fire frequency were variable. Summer forb richness increased under high fire frequency, while C4 grasses, spring forbs, and nitrogen-fixing species decreased with fire exclusion. On mesic and wet-mesic sites, vegetation structure measured by the ratio of woody to graminoid species was negatively correlated with abundance of forbs and with fire frequency. Our findings that species richness responds unimodally to an environmental-productivity gradient, and that fire exclusion increases woody vegetation and leads to loss

  20. Effects of water level, shade and time on germination and growth of freshwater marsh plants along a simulated successional gradient

    USGS Publications Warehouse

    Kellogg, C.H.; Bridgham, S.D.; Leicht, S.A.

    2003-01-01

    1. We examined the effect of soil organic content (1.4, 3.6, 7.2% soil C), water level (+2, -1, -4 cm from soil surface) and duration (13 or 33 days) on 10 species that varied in abundance during succession in freshwater marshes. We also determined the effect of shade (0, 40, 80% shade) and soil organic content (1.4 and 7.2% soil C) on germination of six species over 62 days with water 0.5 cm below the soil surface. 2. Water level consistently affected species germination on both dates. Above-ground biomass was generally higher with increasing organic content of soil, but shade had little effect on germination or height. 3 The hydrologic zone in which species were found in the field was a good indicator of the response of germination to hydrology. Both early successional species and species wide-spread across the successional gradient show similar germination on all organic contents, while later successional species appear to germinate best at higher organic contents. 4. Successional changes in soils are capable of affecting plant community development, independent of disturbance.

  1. Outcomes in Patients With Early-Stage Hypopharyngeal Cancer Treated With Radiotherapy

    SciTech Connect

    Yoshimura, Ryo-ichi; Kagami, Yoshikazu; Ito, Yoshinori; Asai, Masao; Mayahara, Hiroshi; Sumi, Minako; Itami, Jun

    2010-07-15

    Purpose: To analyze the outcome in patients with early-stage hypopharyngeal cancer (HPC) who were treated with radiotherapy (RT). Methods and Materials: Between February 1988 and February 2007, 77 patients with Stage I or Stage II HPC underwent definitive RT in the Division of Radiation Oncology at the National Cancer Center Hospital. Eleven of the patients received local irradiation, and the other 66 patients received elective bilateral neck irradiation and booster irradiation to the primary lesion. The median follow-up period for all the patients was 33 months from the start of RT, ranging from 3 to 229 months. Results: The rates of overall survival, HPC-specific survival, HPC recurrence-free survival, and local control with laryngeal voice preservation for the 77 patients at 5 years were 47%, 74%, 57%, and 70%, respectively. The survival rates were not affected by the patient characteristics or treatment factors, but the RT field was significantly correlated with local control in a multivariate analysis. Seven of the patients had Grade 3 or greater complications, but these complications occurred after salvage surgery in 6 of the patients. Of the 77 patients, 83% had synchronous or metachronous malignancies, but these malignancies did not influence the survival of the patients if the malignancies were detected at an early stage. Conclusion: RT is an appropriate treatment method for early-stage HPC. However, because synchronous or metachronous malignancies occur at a relatively high frequency, careful follow-up and the early detection of such malignancies are critical.

  2. Minimally Invasive Surgery for Early-Stage Lung Cancer: From Innovation to Standard of Care.

    PubMed

    White, Abby; Swanson, Scott J

    2016-11-15

    The era of minimally invasive surgery for lung cancer follows decades of research; the collection and interpretation of countless qualitative and quantitative data points; and tireless efforts by a few pioneering thoracic surgeons who believed they could deliver a safe and oncologically sound operation with less tissue trauma, an improved physiologic profile, and fewer complications than traditional open surgery. This review highlights those efforts and the role of minimally invasive surgery for early-stage lung cancer in light of evolving technology, the emerging understanding of the biology of early-stage lung cancer, and lung cancer screening.

  3. Highly-accurate metabolomic detection of early-stage ovarian cancer

    PubMed Central

    Gaul, David A.; Mezencev, Roman; Long, Tran Q.; Jones, Christina M.; Benigno, Benedict B.; Gray, Alexander; Fernández, Facundo M.; McDonald, John F.

    2015-01-01

    High performance mass spectrometry was employed to interrogate the serum metabolome of early-stage ovarian cancer (OC) patients and age-matched control women. The resulting spectral features were used to establish a linear support vector machine (SVM) model of sixteen diagnostic metabolites that are able to identify early-stage OC with 100% accuracy in our patient cohort. The results provide evidence for the importance of lipid and fatty acid metabolism in OC and serve as the foundation of a clinically significant diagnostic test. PMID:26573008

  4. Effects of cigarette smoke exposure on early stage embryos in the rat

    SciTech Connect

    Tachi, Norihide; Aoyama, Mitsuko )

    1989-09-01

    It is well recognized that cigarette smoking in pregnant women exerts many deleterious effects on their progenies; intrauterine growth retardation, and increases in perinatal mortality and premature births. The fetal growth retardation also has been reported in animals exposed to cigarette smoke. The authors previously demonstrated that cigarette smoke exposure in pregnant rats retarded the growth of fetuses from mid to late stages of pregnancy. In addition, the weight of uteri containing embryos in animals inhaling the smoke was smaller, although not significant, than that in the control on day 7 of pregnancy. Based on these findings, it was suggested that the growth of embryos in early stage seemed to be harmfully affected as well as during mid and late stages of pregnancy. However, since the uterine weight in early pregnancy was measured in the previous study instead of the direct observation of early stage embryos, it remained unclear whether the early development of embryos was really influenced by cigarette smoke exposure or not. The present study was designed to observe the effects of cigarette smoke inhalation by pregnant rats on early development of embryos from fertilization to implantation.

  5. Haemoglobin degradation underpins the sensitivity of early ring stage Plasmodium falciparum to artemisinins

    PubMed Central

    Xie, Stanley C.; Dogovski, Con; Hanssen, Eric; Chiu, Francis; Yang, Tuo; Crespo, Maria P.; Stafford, Che; Batinovic, Steven; Teguh, Silvia; Charman, Susan; Klonis, Nectarios; Tilley, Leann

    2016-01-01

    ABSTRACT Current first-line artemisinin antimalarials are threatened by the emergence of resistant Plasmodium falciparum. Decreased sensitivity is evident in the initial (early ring) stage of intraerythrocytic development, meaning that it is crucial to understand the action of artemisinins at this stage. Here, we examined the roles of iron (Fe) ions and haem in artemisinin activation in early rings using Fe ion chelators and a specific haemoglobinase inhibitor (E64d). Quantitative modelling of the antagonism accounted for its complex dependence on the chemical features of the artemisinins and on the drug exposure time, and showed that almost all artemisinin activity in early rings (>80%) is due to haem-mediated activation. The surprising implication that haemoglobin uptake and digestion is active in early rings is supported by identification of active haemoglobinases (falcipains) at this stage. Genetic down-modulation of the expression of the two main cysteine protease haemoglobinases, falcipains 2 and 3, renders early ring stage parasites resistant to artemisinins. This confirms the important role of haemoglobin-degrading falcipains in artemisinin activation, and shows that changes in the rate of artemisinin activation could mediate high-level artemisinin resistance. PMID:26675237

  6. Confidence interval estimation of the difference between two sensitivities to the early disease stage.

    PubMed

    Dong, Tuochuan; Kang, Le; Hutson, Alan; Xiong, Chengjie; Tian, Lili

    2014-03-01

    Although most of the statistical methods for diagnostic studies focus on disease processes with binary disease status, many diseases can be naturally classified into three ordinal diagnostic categories, that is normal, early stage, and fully diseased. For such diseases, the volume under the ROC surface (VUS) is the most commonly used index of diagnostic accuracy. Because the early disease stage is most likely the optimal time window for therapeutic intervention, the sensitivity to the early diseased stage has been suggested as another diagnostic measure. For the purpose of comparing the diagnostic abilities on early disease detection between two markers, it is of interest to estimate the confidence interval of the difference between sensitivities to the early diseased stage. In this paper, we present both parametric and non-parametric methods for this purpose. An extensive simulation study is carried out for a variety of settings for the purpose of evaluating and comparing the performance of the proposed methods. A real example of Alzheimer's disease (AD) is analyzed using the proposed approaches.

  7. Scrub-successional bird community dynamics in young and mature longleaf pine-wiregrass savannahs

    USGS Publications Warehouse

    Krementz, D.G.; Christie, J.S.

    1999-01-01

    Public agencies are required to manage for threatened and endangered species and for biodiversity. However, at times, management for threatened and endangered species precludes consideration of other species. We investigated how managing for red-cockaded woodpeckers (Picoides borealis) and biodiversity at the Savannah River Site (SRS), South Carolina, affected communities of bird species that use early-successional scrub habitat (hereafter, scrub-successional species). Management for red-cockaded woodpeckers at the SRS involved both (1) manipulating mature longleaf pine (Pinus palustris)-wiregrass (Andropogon spp.) stands via canopy thinning, removal of midstory trees, and prescribed burning; and (2) even-aged timber harvesting. The former management practice encouraged red-cockaded woodpeckers to establish new colonies in previously unoccupied stands (hereafter, 'recruitment' stands). The latter management practice is used to remove off-site planted pines and replant with preferred longleaf pines. We conducted a constant-effort mist net study in recruitment and regenerating stands (stands clearcut and planted with longleaf pine) during the breeding seasons of 1995-96. We hypothesized that the scrub-successional bird community in recruitment stands would have greater species richness and higher survival and reproductive rates per species than in regenerating stands. However, recruitment stands always had fewer scrub-successional species (1995:36 species; 1996:31 species) than regenerating stands (1995:54 species; 1996:55 species), and all species that occurred in recruitment stands also occurred in regenerating stands. Species which commonly occurred in both recruitment and regenerating stands had similar adult:juvenile ratios (P > 0.15) and relative proportion of adults in breeding condition (P > 0.05). We detected no difference in survival rates of Bachman's sparrows (Aimophila aestivalis), indigo buntings (Passerina cyanea), and of 'combined' scrub-successional

  8. Modular IPS Machinery Arrangement in Early-Stage Naval Ship Design

    DTIC Science & Technology

    2013-04-01

    Modular IPS Machinery Arrangement in Early -Stage Naval Ship Design David J. Jurkiewicz1 Carderock Division Naval Surface Warfare Center West...design process as part of assessing system-level tradeoffs early within the ship design process. This paper describes a methodology for the...flexibility in the ship design since it is not necessary to align the propeller shaft with the prime movers . Instead, propulsion motors are coupled to the

  9. [Treatment of non-small cell lung carcinoma in early stages].

    PubMed

    Meneses, José Carlos; Avila Martínez, Régulo J; Ponce, Santiago; Zuluaga, Mauricio; Bartolomé, Adela; Gámez, Pablo

    2013-12-01

    Treatment of lung carcinoma is multidisciplinary. There are different therapeutic strategies available, although surgery shows the best results in those patients with lung carcinoma in early stages. Other options such as stereotactic radiation therapy are relegated to patients with small tumors and poor cardiopulmonary reserve or to those who reject surgery. Adjuvant chemotherapy is not justified in patients with stage i of the disease and so double adjuvant chemotherapy should be considered. This adjuvant chemotherapy should be based on cisplatin after surgery in those patients with stages ii and IIIA.

  10. Hydrodynamic instability of elastic-plastic solid plates at the early stage of acceleration

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Sun, Y. B.; Tahir, N. A.

    2015-03-01

    A model is presented for the linear Rayleigh-Taylor instability taking place at the early stage of acceleration of an elastic-plastic solid, when the shock wave is still running into the solid and is driven by a time varying pressure on the interface. When the the shock is formed sufficiently close to the interface, this stage is considered to follow a previous initial phase controlled by the Ritchmyer-Meshkov instability that settles new initial conditions. The model reproduces the behavior of the instability observed in former numerical simulation results and provides a relatively simpler physical picture than the currently existing one for this stage of the instability evolution.

  11. Effects of temperature on survival and development of early life stage Pacific and western brook lampreys

    USGS Publications Warehouse

    Meeuwig, M.H.; Bayer, J.M.; Seelye, J.G.

    2005-01-01

    We examined the effects of temperature (10, 14, 18, and 22??C) on survival and development of Pacific lampreys Lampetra tridentata and western brook lampreys L. richardsoni during embryological and early larval stages. The temperature for zero development was estimated for each species, and the response to temperature was measured as the proportion of individuals surviving to hatch, surviving to the larval stage, and exhibiting abnormalities at the larval stage (i.e., malformations of the body). The estimated temperature for zero development was 4.850C for Pacific lampreys and 4.97??C for western brook lampreys. Survival was greatest at 18??C, followed by 14, 10, and 22??C, significant differences being observed between 22??C and the other temperatures. Overall survival was significantly greater for western brook lampreys than for Pacific lampreys; however, the overall difference in proportion of individuals surviving was only 0.02. Overall survival significantly decreased from the time of hatch (proportion surviving = 0.85) to the larval stage (0.82; i.e., during the free-embryo stage). The proportion of individuals exhibiting abnormalities at the larval stage was greatest at 22??C, followed by 18, 10, and 14??C, significant differences being observed between 22??C and the other temperatures. These data provide baseline information on the thermal requirements of early life stage Pacific and western brook lampreys and will aid in assessment and prediction of suitable spawning and rearing habitats for these species.

  12. Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

    USGS Publications Warehouse

    DeBoer, Jason A.; Pope, Kevin L.

    2015-01-01

    Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment.

  13. Successional trends in Sonoran Desert abandoned agricultural fields in northern Mexico

    USGS Publications Warehouse

    Castellanos, A.E.; Martinez, M.J.; Llano, J.M.; Halvorson, W.L.; Espiricueta, M.; Espejel, I.

    2005-01-01

    Excessive ground-water use and saline intrusion to the aquifer led, in less than three decades, to an increase in abandoned agricultural fields at La Costa de Hermosillo, within the Sonoran Desert. Using a chronosequence from years since abandonment, patterns of field succession were developed. Contrary to most desert literature, species replacement was found, both in fields with and without saline intrusion. Seasonal photosynthetic capacity as well as water and nitrogen use efficiencies were different in dominant early and late successional plant species. These ecological findings provided a framework for a general explanation of species dominance and replacement within abandoned agricultural fields in the Sonoran Desert. ?? 2004 Elsevier Ltd. All rights reserved.

  14. Outcomes of laparoscopic fertility-sparing surgery in clinically early-stage epithelial ovarian cancer

    PubMed Central

    Park, Jin-Young; Lee, Yoo-Young; Kim, Tae-Joong; Kim, Byoung-Gie; Bae, Duk-Soo

    2016-01-01

    Objective Fertility-sparing surgery (FSS) is becoming an important technique in the surgical management of young women with early-stage epithelial ovarian cancer (EOC). We retrospectively evaluated the outcome of laparoscopic FSS in presumed clinically early-stage EOC. Methods We retrospectively searched databases of patients who received laparoscopic FSS for EOC between January 1999 and December 2012 at Samsung Medical Center. Women aged ≤40 years were included. The perioperative, oncological, and obstetric outcomes of these patients were evaluated. Results A total of 18 patients was evaluated. The median age of the patients was 33.5 years (range, 14 to 40 years). The number of patients with clinically stage IA and IC was 6 (33.3%) and 12 (66.7%), respectively. There were 7 (38.9%), 5 (27.8%), 3 (16.7%), and 3 patients (16.7%) with mucinous, endometrioid, clear cell, and serous tumor types, respectively. Complete surgical staging to preserve the uterus and one ovary with adnexa was performed in 4 patients (22.2%). Two out of them were upstaged to The International Federation of Gynecology and Obstetrics stage IIIA1. During the median follow-up of 47.3 months (range, 11.5 to 195.3 months), there were no perioperative or long term surgical complications. Four women (22.2%) conceived after their respective ovarian cancer treatments. Three (16.7%) of them completed full-term delivery and one is expecting a baby. One patient had disease recurrence. No patient died of the disease. Conclusion FSS in young patients with presumed clinically early-stage EOC is a challenging and cautious procedure. Further studies are urgent to determine the safety and feasibility of laparoscopic FSS in young patients with presumed clinically early-stage EOC. PMID:26768783

  15. Sensitivity of early life stages of white sturgeon, rainbow trout, and fathead minnow to copper.

    PubMed

    Vardy, David W; Oellers, Johanna; Doering, Jon A; Hollert, Henner; Giesy, John P; Hecker, Markus

    2013-01-01

    Populations of white sturgeon (WS; Acipenser transmontanus) are in decline in several parts of the United States and Canada, attributed primarily to poor recruitment caused by degradation of habitats, including pollution with contaminants such as metals. Little is known about sensitivity of WS to contaminants or metals such as copper (Cu). Here, acute (96 h) mortalities of WS early life stages due to exposure to Cu under laboratory conditions are reported. Two standard test species, rainbow trout (Oncorhynchus mykiss) and fathead minnow (Pimephales promelas), were exposed in parallel to determine relative sensitivity among species. Swim-up larvae [15 days post-hatch (dph)] and early juveniles (40-45 dph) of WS were more sensitive to Cu (LC(50) = 10 and 9-17 μg/L, respectively) than were yolksac larvae (8 dph; LC(50) = 22 μg/L) and the later juvenile life stage (100 dph; LC(50) = 54 μg/L). WS were more sensitive to Cu than rainbow trout and fathead minnow at all comparable life stages tested. Yolksac larvae of rainbow trout and fathead minnow were 1.8 and 4.6 times, respectively, more tolerant than WS, while swim-up and juvenile life stages of rainbow trout were between 1.4- and 2.4-times more tolerant than WS. When plotted in a species sensitivity distribution with other fishes, the mean acute toxicity value for early life stage WS was ranked between the 1st and 2nd centile. The WS life stage of greatest Cu sensitivity coincides with the beginning of active feeding and close association with sediment, possibly increasing risk. WS early life stages are sensitive to aqueous copper exposure and site-specific water quality guidelines and criteria should be evaluated closely to ensure adequate protection.

  16. Patient Perspectives on Deep Brain Stimulation Clinical Research in Early Stage Parkinson's Disease.

    PubMed

    Heusinkveld, Lauren; Hacker, Mallory; Turchan, Maxim; Bollig, Madelyn; Tamargo, Christina; Fisher, William; McLaughlin, Lauren; Martig, Adria; Charles, David

    2017-01-01

    The FDA has approved a multicenter, double-blind, Phase III, pivotal trial testing deep brain stimulation (DBS) in 280 people with very early stage Parkinson's disease (PD; IDE#G050016). In partnership with The Michael J. Fox Foundation for Parkinson's Research, we conducted a survey to investigate motivating factors, barriers, and gender differences among potentially eligible patients for participation in a trial testing DBS in early PD compared to standard medical treatment. The majority of survey respondents (72%) indicated they would consider learning more about participating. Early PD patients are therefore likely to consider enrolling in trials of invasive therapies that may slow symptom progression and help future patients.

  17. Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar

    USGS Publications Warehouse

    Duffy, Tara A.; Iwanowicz, Luke R.; McCormick, Stephen D.

    2014-01-01

    Atlantic salmon (Salmo salar) are endangered anadromous fish that may be exposed to feminizing endocrine disrupting compounds (EDCs) during early development, potentially altering physiological capacities, survival and fitness. To assess differential life stage sensitivity to common EDCs, we carried out short-term (four day) exposures using three doses each of 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and nonylphenol (NP) on four early life stages; embryos, yolk-sac larvae, feeding fry and one year old smolts. Differential response was compared using vitellogenin (Vtg, a precursor egg protein) gene transcription. Smolts were also examined for impacts on plasma Vtg, cortisol, thyroid hormones (T4/T3) and hepatosomatic index (HSI). Compound-related mortality was not observed in any life stage, but Vtg mRNA was elevated in a dose-dependent manner in yolk-sac larvae, fry and smolts but not in embyos. The estrogens EE2 and E2 were consistently stronger inducers of Vtg than NP. Embryos responded significantly to the highest concentration of EE2 only, while older life stages responded to the highest doses of all three compounds, as well as intermediate doses of EE2 and E2. Maximal transcription was greater for fry among the three earliest life stages, suggesting fry may be the most responsive life stage in early development. Smolt plasma Vtg was also significantly increased, and this response was observed at lower doses of each compound than was detected by gene transcription suggesting this is a more sensitive indicator at this life stage. HSI was increased at the highest doses of EE2 and E2 and plasma T3 decreased at the highest dose of EE2. Our results indicate that all life stages after hatching are potentially sensitive to endocrine disruption by estrogenic compounds and that physiological responses were altered over a short window of exposure, indicating the potential for these compounds to impact fish in the wild.

  18. Carcinoma of the uterine cervix stage IB and early stage II. Prognostic value of the histological tumor regression after initial brachytherapy

    SciTech Connect

    Calais, G.; Le Floch, O.; Chauvet, B.; Reynaud-Bougnoux, A.; Bougnoux, P. )

    1989-12-01

    In our center limited centro pelvic invasive carcinomas of the uterine cervix (less than 4 cm) are treated with brachytherapy and surgery. With these therapeutic modalities no residual carcinoma was observed for 80% of the patients. The purpose of this study was to evaluate our results with this treatment, and to evaluate the prognostic value of the pathological status of the cervix. From 1976 to 1987 we have treated 115 patients with these modalities. Staging system used was the FIGO classification modified for Stage II (divided in early Stage II and late Stage II). Patients were Stage IB (70 cases) and early Stage II (45 cases); 60 Gy were delivered with utero vaginal brachytherapy before any treatment. Six weeks later a radical hysterectomy with pelvic lymphadenectomy was performed. Twenty-one patients with positive nodes received a pelvic radiotherapy (45 to 55 Gy). Local control rate was 97% (100% for Stage IB and 93% for early Stage II). Uncorrected 10-year actuarial survival rate was 96% for Stage IB and 80% for early Stage II patients. No treatment failure was observed for Stage IB patients. Ninety-two patients (80%) had no residual carcinoma in the cervix (group 1) and 23 patients (20%) had a residual tumor (group 2). The sterilization rate of the cervix was 87% for Stage IB tumors versus 69% for early Stage II, and was 82% for N- patients versus 68% for N+ patients. Ten year actuarial survival rate was 92% for group 1 and 78% for group 2 (p = 0, 1). Grade 3 complications rate was 6%. We conclude that brachytherapy + surgery is a safe treatment for limited centro pelvic carcinomas of the uterine cervix (especially Stage IB) and that pathological status of the cervix after brachytherapy is not a prognostic factor.

  19. "It's the Bread and Butter of Our Practice": Experiencing the Early Years Foundation Stage

    ERIC Educational Resources Information Center

    Roberts-Holmes, Guy

    2012-01-01

    This article presents the experiences of nursery and primary head teachers (n = 12) on the English Early Years Foundation Stage (EYFS) after its first year of implementation in 2010. Findings are drawn from a subset of data (head teachers of primary and nursery schools) which forms part of a larger Department for Children, Schools and Families…

  20. Alternatives to Mechanical Drills for the Early Stages of Language Practice in Foreign Language Textbooks

    ERIC Educational Resources Information Center

    Aski, Janice M.

    2005-01-01

    There is a growing body of research indicating that mechanical drills do not facilitate the development of explicit or implicit knowledge. This study identifies the inadequate aspects of mechanical drills and offers alternative activities for the early stages of language practice, whose formats and features comply with recent research in the…

  1. Memory Club: A Group Intervention for People with Early-Stage Dementia and Their Care Partners

    ERIC Educational Resources Information Center

    Zarit, Steven H.; Femia, Elia E.; Watson, Jennifer; Rice-Oeschger, Laura; Kakos, Bernadette

    2004-01-01

    Purpose: Diagnosis of dementia in its early stages presents a window of opportunity for examining the immediate and long-term consequences of the illness at a point when the individual with memory loss can still participate in decision making. Design and Methods: Memory Club is a l0-session group program designed to provide information about…

  2. Test Design Optimization in CAT Early Stage with the Nominal Response Model

    ERIC Educational Resources Information Center

    Passos, Valeria Lima; Berger, Martijn P. F.; Tan, Frans E.

    2007-01-01

    The early stage of computerized adaptive testing (CAT) refers to the phase of the trait estimation during the administration of only a few items. This phase can be characterized by bias and instability of estimation. In this study, an item selection criterion is introduced in an attempt to lessen this instability: the D-optimality criterion. A…

  3. Treatment of Early-Stage Pressure Ulcers by Using Autologous Adipose Tissue Grafts

    PubMed Central

    Marangi, Giovanni Francesco; Pallara, Tiziano; Cagli, Barbara; Schena, Emiliano; Giurazza, Francesco; Faiella, Elio; Zobel, Bruno Beomonte; Persichetti, Paolo

    2014-01-01

    Assessing pressure ulcers (PUs) in early stages allows patients to receive safer treatment. Up to now, in addition to clinical evaluation, ultrasonography seems to be the most suitable technique to achieve this goal. Several treatments are applied to prevent ulcer progression but none of them is totally effective. Furthermore, the in-depth knowledge of fat regenerative properties has led to a wide use of it. With this study the authors aim at introducing a new approach to cure and prevent the worsening of early-stage PUs by using fat grafts. The authors selected 42 patients who showed clinical and ultrasonographic evidence of early-stage PUs. Values of skin thickness, fascial integrity, and subcutaneous vascularity were recorded both on the PU area and the healthy trochanteric one, used as control region. Fat grafting was performed on all patients. At three months, abnormal ultrasonographic findings, such as reduction of cutaneous and subcutaneous thickness, discontinuous fascia, and decrease in subcutaneous vascularity, all were modified with respect to almost all the corresponding parameters of the control region. Results highlight that the use of fat grafts proved to be an effective treatment for early-stage PUs, especially in the care of neurological and chronic bedridden patients. PMID:24818019

  4. Implementation of the TMS in the early stages of Parkinson's disease.

    PubMed

    Guekht, A; Selikhova, M; Serkin, G; Gusev, E

    2005-01-01

    47 PD patients were investigated with the single-pulse TMS to find out changes in motor evoked potential and motor conduction related to the stage of minimal motor symptoms and its further deterioration in groups with the different clinical types of the disease. The investigation revealed a markedly longer MEP duration along with the increased number of phases, than in controls, which were bilateral and advanced despite the minimal unilateral motor symptoms. There was also increased MEP amplitude in facilitation, with a higher degree of asymmetry, compared to controls. Patients with predominant rigid clinical forms had the further MEP duration and amplitude increase proportionally to bradikinesia and rigidity in the early stages of the disease. Patients with tremor predominant forms had no further changes in the MEP duration and amplitude, but had their motor CCT decreased in the early stages. Patients with the akinetic form were characterized by the asymmetric increase in the MEP Amplitude in relaxation and motor CCT shortening. Thus, TMS allows us to diagnose early the possible central motor changes secondary to Parkinson's disease, reveals the difference in compensational capacity according to the clinical type of the disease and helps in monitoring of the severity of motor changes in early stages.

  5. Sydney, Australia Community Meets Classroom: Celebrating Families and Difference in the Early Stages of Primary Education

    ERIC Educational Resources Information Center

    Burns, Kellie

    2006-01-01

    Teachers and teacher educators are often hard pressed to find resources that creatively integrate lesbian, gay, bisexual, transgender (LGBT), and intersex issues into the early stages of primary education. While there is a growing number of academics who stress the importance of addressing topics of sexual and gender diversity during the early…

  6. Arthroscopic core decompression of the lunate in early stage Kienbock disease of the lunate.

    PubMed

    Bain, Gregory I; Smith, Michael L; Watts, Adam C

    2011-03-01

    Since the first description of Kienbock disease in 1910, the etiology and treatment have remained controversial topics. Core decompression is an accepted treatment option in early-stage avascular necrosis of the femoral head, and more recently the humeral head. This paper reports the technique of arthroscopic fluoroscopically guided core decompression of the lunate with 6-year results.

  7. 77 FR 74908 - Small Business Investment Companies-Early Stage SBICs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-18

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Small Business Investment Companies--Early Stage SBICs AGENCY: U.S. Small Business Administration... managers to submit the preliminary materials discussed in Section II, in the form of the Small...

  8. Early-Stage Chunking of Finger Tapping Sequences by Persons Who Stutter and Fluent Speakers

    ERIC Educational Resources Information Center

    Smits-Bandstra, Sarah; De Nil, Luc F.

    2013-01-01

    This research note explored the hypothesis that chunking differences underlie the slow finger-tap sequencing performance reported in the literature for persons who stutter (PWS) relative to fluent speakers (PNS). Early-stage chunking was defined as an immediate and spontaneous tendency to organize a long sequence into pauses, for motor planning,…

  9. Evaluation of hypothesized adverse outcome pathway linking thyroid peroxidase inhibition to fish early life stage toxicity

    EPA Science Inventory

    There is an interest in developing alternatives to the fish early-life stage (FELS) test (OECD test guideline 210), for predicting adverse outcomes (e.g., impacts on growth and survival) using less resource-intensive methods. Development and characterization of adverse outcome pa...

  10. Prostatic Fatty Acids and Cancer Recurrence Following Radical Prostatectomy for Early-Stage Prostate Cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: Results from some observational studies suggest that diet and energy balance influence the clinical course of early-stage prostate cancer. To evaluate possible mechanisms, we prospectively examined the relation between prostatic concentrations of fatty acids at diagnosis and cancer recurr...

  11. Fish early life stage: Developing AOPs to support targeted reduction and replacement

    EPA Science Inventory

    There is an interest in developing alternatives to the fish early-life stage (FELS) test (OECD test guideline 210), for predicting adverse chronic toxicity outcomes (e.g., impacts on growth and survival). Development and characterization of adverse outcome pathways (AOPs) related...

  12. 13 CFR 107.1182 - Valuation requirements for Early Stage SBICs based on Capital Impairment Percentage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1182 Valuation... designated by SBA. Conditional Commitments by SBA To Reserve Leverage for a Licensee...

  13. 13 CFR 107.1182 - Valuation requirements for Early Stage SBICs based on Capital Impairment Percentage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Special Rules for Leverage Issued by An Early Stage Sbic § 107.1182 Valuation... designated by SBA. Conditional Commitments by SBA To Reserve Leverage for a Licensee...

  14. Communication in the Early Stage of Language Development in Children with CHARGE Syndrome

    ERIC Educational Resources Information Center

    Peltokorpi, Sini; Huttunen, Kerttu

    2008-01-01

    CHARGE syndrome is characterized by multiple physical abnormalities, and impaired vision and hearing. In this pilot study, communication in the early stage of language development in three one- to eight-year-old children with CHARGE syndrome was explored using video recorded free-play interaction sessions and a parental questionnaire. The children…

  15. Prolonged Exposure Therapy for a Vietnam Veteran with PTSD and Early-Stage Dementia

    ERIC Educational Resources Information Center

    Duax, Jeanne M.; Waldron-Perrine, Brigid; Rauch, Sheila A. M.; Adams, Kenneth M.

    2013-01-01

    Although prolonged exposure therapy (PE) is considered an evidence-based treatment for PTSD, there has been little published about the use of this treatment for older adults with comorbid early-stage dementia. As the number of older adults in the United States continues to grow, so will their unique mental health needs. The present article…

  16. Association Between Increased Vascular Density and Loss of Protective RAS in Early-stage NPDR

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, Krishnan; Raghunandan, Sneha; Vyas, Ruchi J.; Vu, Amanda C.; Bryant, Douglas; Yaqian, Duan; Knecht, Brenda E.; Grant, Maria B.; Chalam, K. V.; Parsons-Wingerter, Patricia

    2016-01-01

    Our hypothesis predicts that retinal blood vessels increase in density during early-stage progression to moderate nonproliferative diabetic retinopathy (NPDR). The renin-angiotensin system (RAS) is implicated in the pathogenesis of DR and in the function of circulating angiogenic cells (CACs), a critical bone marrow-derived population that is instrumental in vascular repair.

  17. Patients with Old Age or Proximal Tumors Benefit from Metabolic Syndrome in Early Stage Gastric Cancer

    PubMed Central

    Zhang, Ying; Liu, Jian-xin; Yu, Hong-mei; Liang, Wei-ping; Jin, Ying; Ren, Chao; He, Ming-ming; Chen, Wei-wei; Luo, Hui-yan; Wang, Zhi-qiang; Zhang, Dong-sheng; Wang, Feng-hua; Li, Yu-hong; Xu, Rui-hua

    2014-01-01

    Background Metabolic syndrome and/or its components have been demonstrated to be risk factors for several cancers. They are also found to influence survival in breast, colon and prostate cancer, but the prognostic value of metabolic syndrome in gastric cancer has not been investigated. Methods Clinical data and pre-treatment information of metabolic syndrome of 587 patients diagnosed with early stage gastric cancer were retrospectively collected. The associations of metabolic syndrome and/or its components with clinical characteristics and overall survival in early stage gastric cancer were analyzed. Results Metabolic syndrome was identified to be associated with a higher tumor cell differentiation (P = 0.036). Metabolic syndrome was also demonstrated to be a significant and independent predictor for better survival in patients aged >50 years old (P = 0.009 in multivariate analysis) or patients with proximal gastric cancer (P = 0.047 in multivariate analysis). No association was found between single metabolic syndrome component and overall survival in early stage gastric cancer. In addition, patients with hypertension might have a trend of better survival through a good control of blood pressure (P = 0.052 in univariate analysis). Conclusions Metabolic syndrome was associated with a better tumor cell differentiation in patients with early stage gastric cancer. Moreover, metabolic syndrome was a significant and independent predictor for better survival in patients with old age or proximal tumors. PMID:24599168

  18. 76 FR 81430 - Small Business Investment Companies-Early Stage SBICs; Public Webinars

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ... ADMINISTRATION 13 CFR Part 107 Small Business Investment Companies--Early Stage SBICs; Public Webinars AGENCY: U.S. Small Business Administration. ACTION: Notice of public Webinars. SUMMARY: The U.S. Small Business Administration (SBA) announces that it is holding a series of public Webinars regarding...

  19. Responding to the Challenges of Active Citizenship through the Revised UK Early Years Foundation Stage Curriculum

    ERIC Educational Resources Information Center

    Baker, Fiona S.

    2013-01-01

    The revised UK Early Years Foundation Stage (EYFS) now places a stronger emphasis on personal, social and emotional development (PSED) as one of its three prime areas. PSED has three characteristics of learning: active learning, creating and thinking critically, and playing and exploring. These aspects of the revised EYFS closely align with the…

  20. Concurrent Data Elicitation Procedures, Processes, and the Early Stages of L2 Learning: A Critical Overview

    ERIC Educational Resources Information Center

    Leow, Ronald P.; Grey, Sarah; Marijuan, Silvia; Moorman, Colleen

    2014-01-01

    Given the current methodological interest in eliciting direct data on the cognitive processes L2 learners employ as they interact with L2 data during the early stages of the learning process, this article takes a critical and comparative look at three concurrent data elicitation procedures currently employed in the SLA literature: Think aloud (TA)…

  1. Perinatal Risks Associated with Early Vanishing Twin Syndrome following Transfer of Cleavage- or Blastocyst-Stage Embryos

    PubMed Central

    Pryor, Katherine P.; Petrini, Allison C.; Lekovich, Jovana P.; Stahl, Jaclyn; Elias, Rony T.; Spandorfer, Steven D.

    2016-01-01

    Objective. To investigate whether the perinatal risks associated with early vanishing twin (VT) syndrome differ between cleavage- or blastocyst-stage embryo transfers (ET) in fresh in vitro fertilization (IVF) cycles. Methods. Retrospective, single-center, cohort study of IVF cycles with fresh cleavage- or blastocyst-stage ETs resulting in a live singleton birth. The incidence of preterm birth (PTB), low birth weight (LBW), and very low birth weight (VLBW) was compared between cleavage- and blastocyst-stage ET cycles complicated by early VT. Results. 7241 patients had live singleton births. Early VT was observed in 709/6134 (11.6%) and 70/1107 (6.32%) patients undergoing cleavage-stage and blastocyst-stage ETs, respectively. Patients in the blastocyst-stage group were younger compared to the cleavage-stage group. The cleavage-stage group had a similar birth weight compared to the blastocyst-stage group. There was no difference in the incidence of PTB (9.87% versus 8.57%), LBW (11.1% versus 11.4%), or VLBW (1.13 versus 1.43%) when comparing the cleavage-stage early VT and blastocyst-stage early VT groups, even after adjustment with logistic regression. Conclusions. Our study highlights that the adverse perinatal risks of PTB, LBW, and VLBW associated with early VT syndrome are similar in patients undergoing cleavage-stage or blastocyst-stage ETs during fresh IVF cycles. PMID:28101380

  2. Following iron speciation in the early stages of magnetite magnetosome biomineralization

    SciTech Connect

    Firlar, Emre; Perez-Gonzalez, Teresa; Olszewska, Agata; Faivre, Damien; Prozorov, Tanya

    2016-02-26

    Understanding magnetosome magnetite biomineralization is of fundamental interest to devising the strategies for bioinspired synthesis of magnetic materials at the nanoscale. Thus, we investigated the early stages of magnetosome formation in this work and correlated the size and emergent crystallinity of magnetosome nanoparticles with the changes in chemical environment of iron and oxygen by utilizing advanced analytical electron microscopy techniques. We observed that magnetosomes in the early stages of biomineralization with the sizes of 5–10 nm were amorphous, with a majority of iron present as Fe3+, indicative of ferric hydroxide. The magnetosomes with intermediate sizes showed partially crystalline structure with a majority of iron present as Fe3+ and trace amounts of Fe2+. The fully maturated magnetosomes were indexed to magnetite. Furthermore, our approach provides spatially resolved structural and chemical information of individual magnetosomes with different particle sizes, attributed to magnetosomes at different stages of biomineralization.

  3. The δ-cyclin expression at early stages of embryogenesis of Brassica rapa L. under clinorotation

    NASA Astrophysics Data System (ADS)

    Artemenko, O. A.; Popova, A. F.

    We present some results of comparison studying of Brassica embryo development and the δ-cyclin genes expression under slow horizontal clinorotation and in the laboratory control. Some backlog of the δ1-cyclin genes expression at early stages of embryogenesis under clinorotation was revealed in comparison with the laboratory control. The similar level of the δ3-cyclin expression at all stages of embryo formation (from one to nine days) in both variants is shown. Some delays in the rate of Brassica rapa embryo development under clinorotation in comparison with the laboratory control can be a result of decrease of a level and some backlog of the δ1-cyclin expression at early stages of embryogenesis.

  4. Following iron speciation in the early stages of magnetite magnetosome biomineralization

    DOE PAGES

    Firlar, Emre; Perez-Gonzalez, Teresa; Olszewska, Agata; ...

    2016-02-26

    Understanding magnetosome magnetite biomineralization is of fundamental interest to devising the strategies for bioinspired synthesis of magnetic materials at the nanoscale. Thus, we investigated the early stages of magnetosome formation in this work and correlated the size and emergent crystallinity of magnetosome nanoparticles with the changes in chemical environment of iron and oxygen by utilizing advanced analytical electron microscopy techniques. We observed that magnetosomes in the early stages of biomineralization with the sizes of 5–10 nm were amorphous, with a majority of iron present as Fe3+, indicative of ferric hydroxide. The magnetosomes with intermediate sizes showed partially crystalline structure withmore » a majority of iron present as Fe3+ and trace amounts of Fe2+. The fully maturated magnetosomes were indexed to magnetite. Furthermore, our approach provides spatially resolved structural and chemical information of individual magnetosomes with different particle sizes, attributed to magnetosomes at different stages of biomineralization.« less

  5. Aquaporin expression in the cerebral cortex is increased at early stages of Alzheimer disease.

    PubMed

    Pérez, Esther; Barrachina, Marta; Rodríguez, Agustín; Torrejón-Escribano, Benjamín; Boada, Mercé; Hernández, Isabel; Sánchez, Marisa; Ferrer, Isidre

    2007-01-12

    Abnormalities in the cerebral microvasculature are common in Alzheimer disease (AD). Expression levels of the water channels aquaporin 1 and aquaporin 4 (AQP1, AQP4) were examined in AD cases by gel electrophoresis and Western blotting, and densitometric values normalized with beta-actin were compared with corresponding values in age-matched controls processed in parallel. In addition, samples of cases with Pick disease (PiD) were examined for comparative purposes. A significant increase in the expression levels of AQP1 was observed in AD stage II (following Braak and Braak classification). Individual variations were seen in advanced stages which resulted in non-significant differences between AD stages V-VI and age-matched controls. No differences in AQP1 levels were observed between familial AD cases (FAD, all of them at advanced stages) and corresponding age-matched controls. Immunohistochemistry showed increased AQP1 in astrocytes at early stages of AD. Double-labelling immunofluorescence and confocal microscopy disclosed AQP1 immunoreactivity at the cell surface of astrocytes which were recognized with anti-glial fibrillary acidic protein antibodies. No differences in the levels of AQP4 were observed in AD, FAD and PiD when compared with corresponding controls. These results indicate abnormal expression of AQP1 in astrocytes in AD, and they add support to the idea that abnormal regulation of mechanisms involved in the control of water fluxes occurs at early stages in AD.

  6. Apathy in untreated early-stage Parkinson disease: relationship with other non-motor symptoms.

    PubMed

    Dujardin, Kathy; Langlois, Carole; Plomhause, Lucie; Carette, Anne-Sophie; Delliaux, Marie; Duhamel, Alain; Defebvre, Luc

    2014-12-01

    Apathy is a frequent and disabling behavioral disorder in patients with Parkinson's disease (PD). Its prevalence in treatment-naive patients with early-stage PD has not been extensively investigated. Moreover, whether apathy is related to other non-motor symptoms in early-stage PD is unknown. Our objective was to determine the prevalence and features of apathy and associated factors in a group of treatment-naive patients with early-stage PD. Ninety-five treatment-naive patients with early-stage PD participated in the study. Apathy, depression, motor symptoms, and overall cognitive efficiency were assessed. The presence of the main non-motor symptoms was checked during a detailed clinical interview. Group comparisons were carried out to investigate the association with apathy. Eighteen patients (18.95%) were diagnosed as apathetic, and five of the latter had concomitant depression. Apathetic patients had significantly more severe motor symptoms (P < 0.001) and a lower cognitive status (P = 0.032) than non-apathetic patients. When considering non-motor symptoms, apathy was significantly associated only with fatigue (P = 0.007) and anhedonia (P = 0.010), both of which were more prevalent in apathetic patients than in non-apathetic patients. In treatment-naive patients with early-stage PD, apathy was significantly associated with more severe motor symptoms and a lower cognitive status. After adjustment for these factors, apathy appeared to be a relatively isolated, independent symptom because the only other associated non-motor symptoms were fatigue and anhedonia.

  7. Early stages of probable Alzheimer disease are associated with changes in platelet amyloid precursor protein forms.

    PubMed

    Borroni, B; Colciaghi, F; Corsini, P; Akkawi, N; Rozzini, L; Del Zotto, E; Talarico, G; Cattabeni, F; Lenzi, G L; Di Luca, M; Padovani, A

    2002-12-01

    Previous findings demonstrated an altered pattern of amyloid precursor protein (APP) forms in platelets of Alzheimer disease (AD) patients, compared both with healthy control subjects or patients with non-Alzheimer-type dementia. The present study aims to evaluate whether platelet APP form ratio (APPr) is altered in patients with early stage AD. We selected 40 patients with early stage AD and 40 age-matched healthy controls. Compared with controls (mean+/-SD=0.91+/-0.3), mean APPr was decreased in AD (mean+/-SD=0.46+/-0.26, p<0.0001). Sixteen very mild AD patients (clinical dementia rating=0.5), identified among the AD group, showed a significant decrease of APPr values (mean+/-SD=0.50+/-0.3, p<0.0001). These findings indicate that alteration of APP processing in platelets is an early event and suggest that this assay might be of diagnostic value in differentiating mild AD from normal ageing.

  8. Effects of prometryne on early life stages of common carp (Cyprinus carpio L.).

    PubMed

    Velisek, Josef; Stara, Alzbeta; Koutnik, Dalibor; Machova, Jana

    2015-02-01

    Toxicity of prometryne to early life stages of common carp was assessed. On the basis of accumulated mortality in the experimental groups lowest observed-effect concentration (LOEC) was estimated as 1100 µg/l; and no observed-effect concentration (NOEC) was 850 µg/l. Fulton's condition factor was significantly lower than in controls in fish exposed to 4000 µg/l after 7, 14, and 21 days. By day 14, fish exposed to 4000 µg/l prometryne showed significantly lower mass and total length compared to controls. Fish exposed the 1200 and 4000 µg/l showed delay in development, severe hyperaemia in gill, liver, and caudal and cranial kidney. Subchronic prometryne exposure of early-life stages of common carp at concentrations of 1200 and 4000 µg/l affected their survival, growth rate, early ontogeny, and histology.

  9. Strong correlation between early stage atherosclerosis and electromechanical coupling of aorta

    NASA Astrophysics Data System (ADS)

    Liu, X. Y.; Yan, F.; Niu, L. L.; Chen, Q. N.; Zheng, H. R.; Li, J. Y.

    2016-03-01

    Atherosclerosis is the underlying cause of cardiovascular diseases that are responsible for many deaths in the world, and the early diagnosis of atherosclerosis is highly desirable. The existing imaging methods, however, are not capable of detecting the early stage of atherosclerosis development due to their limited spatial resolution. Using piezoresponse force microscopy (PFM), we show that the piezoelectric response of an aortic wall increases as atherosclerosis advances, while the stiffness of the aorta shows a less evident correlation with atherosclerosis. Furthermore, we show that there is strong correlation between the coercive electric field necessary to switch the polarity of the artery and the development of atherosclerosis. Thus by measuring the electromechanical coupling of the aortic wall, it is possible to probe atherosclerosis at the early stage of its development, not only improving the spatial resolution by orders of magnitude, but also providing comprehensive quantitative information on the biomechanical properties of the artery.

  10. Early developmental stages of Ascaris lumbricoides featured by high-resolution mass spectrometry.

    PubMed

    Melo, Carlos Fernando Odir Rodrigues; Esteves, Cibele Zanardi; de Oliveira, Rosimeire Nunes; Guerreiro, Tatiane Melina; de Oliveira, Diogo Noin; Lima, Estela de Oliveira; Miné, Júlio César; Allegretti, Silmara Marques; Catharino, Rodrigo Ramos

    2016-11-01

    Ascaris lumbricoides is responsible for a highly disseminated helminth parasitic disease, ascariosis, a relevant parasitosis that responds for great financial burden on the public health system of developing countries. In this work, metabolic fingerprinting using high-resolution mass spectrometry (HRMS) was employed to identify marker molecules from A. lumbricoides in different development stages. We have identified nine biomarkers, such as pheromones and steroidal prohormones in early stages, among other molecules in late development stages, making up four molecules for fertilized eggs, four marker molecules for first larvae (L1) and one marker molecule for third larvae (L3). Therefore, our findings indicate that this approach is suitable for biochemical characterization of A. lumbricoides development stages. Moreover, the straightforward analytical method employed, with almost no sample preparation from a complex matrix (feces) using high-resolution mass spectrometry, suggests that it is possible to seek for an easier and faster way to study animal molding processes.

  11. Astronomical Constraints on the Duration of Early Jurassic Stages and Global Carbon Cycle and Climatic Perturbations

    NASA Astrophysics Data System (ADS)

    Ruhl, M.; Hesselbo, S. P.; Hinnov, L.; Jenkyns, H. C.; Storm, M.; Xu, W.; Riding, J. B.; Ullmann, C. V.

    2015-12-01

    The Early Jurassic (201.3 to 174.1 Ma) is bracketed by the end-Triassic mass extinction and global warming event, and the Toarcian-Aalenian shift to (global) icehouse conditions (McElwain et al., 1999; Hesselbo et al., 2002; Ruhl et al., 2011; Korte et al., in review). It is further marked by the early Toarcian Oceanic Anoxic Event (T-OAE), with possibly the largest exogenic carbon cycle perturbation of the Mesozoic and related perturbations in global geochemical cycles, climate and the environment, which are linked to large igneous province emplacement in the Karoo-Ferrar region (Jenkyns, 2010; Burgess et al., 2015). Furthermore, Early Jurassic continental rifting and the break-up of Pangaea and subsequent Early Jurassic opening of the Hispanic Corridor and Viking Strait respectively linked the equatorial Tethys Ocean to Eastern Panthalassa and the high-latitude Arctic Boreal realm. This initiated changes in (global) ocean currents and Earth's heat distribution and ultimately was followed by the opening of the proto-North Atlantic (Porter et al., 2013; Korte et al., in review). Here, we present high-resolution (sub-precession scale) elemental concentration data from the Mochras borehole (UK), which represents ~1300m of possibly the most complete and expanded lower Jurassic hemi-pelagic marine sedimentary archive known. We construct a floating ~9 Myr astronomical time-scale for the complete Early Jurassic Pliensbachian stage and biozones. Combined with radiometric and astrochronological constraints on early Jurassic stage boundaries, we construct a new Early Jurassic Time-Scale. With this we assess the duration and rate of change of early Jurassic global carbon cycle and climatic perturbations and we asses fundamental changes in the nature and expression of Early Jurassic long (100 - 1000 kyr) eccentricity cycles.

  12. Characterization of early stage cartilage degradation using diffuse reflectance near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Brown, C. P.; Jayadev, C.; Glyn-Jones, S.; Carr, A. J.; Murray, D. W.; Price, A. J.; Gill, H. S.

    2011-04-01

    Interest in localized and early stage treatment technologies for joint conditions such as osteoarthritis is growing rapidly. It has therefore become important to develop objective measures capable of characterizing the earliest (non-visible) changes associated with degeneration to aid treatment procedures. In addition to assessing tissue before treatment, it is further important to develop an effective, non-destructive means of monitoring post-treatment tissue healing, and of providing the high-quality data needed for trials of developing treatment methods. To investigate its ability to detect the early stages of degeneration in cartilage-on-bone, diffuse reflectance near infrared spectroscopy was applied to normal and osteoarthritic joints. A discriminating function was developed to relate absorbance peaks of interest and track degradation around focal osteoarthritic defects. The function could distinguish between normal and degraded tissue (100% separation of normal tissue from that within 25 mm of a defect) and between different stages of osteoarthritic progression (p < 0.05). This technique allows simple, practical and non-destructive assessment of component-level properties over the full depth of the tissue. It has the potential to increase our understanding of the underlying etiologic and pathogenic processes in early stage degeneration, to assist classification and the development of new treatment methods.

  13. Expression Analysis of Cathepsin F during Embryogenesis and Early Developmental Stage in Olive Flounder (Paralichthys olivaceus)

    PubMed Central

    Lee, Jang-Wook; Lee, Young Mee; Yang, Hyun; Noh, Jae Koo; Kim, Hyun Chul; Park, Choul-Ji; Park, Jong-Won; Hwang, In Joon; Kim, Sung Yeon; Lee, Jeong-Ho

    2013-01-01

    Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder. PMID:25949137

  14. Complexity of resting-state EEG activity in the patients with early-stage Parkinson's disease.

    PubMed

    Yi, Guo-Sheng; Wang, Jiang; Deng, Bin; Wei, Xi-Le

    2017-04-01

    To investigate the abnormal brain activities in the early stage of Parkinson's disease (PD), the electroencephalogram (EEG) signals were recorded with 20 channels from non-dementia PD patients (18 patients, 8 females) and age matched healthy controls (18 subjects, 8 females) during the resting state. Two methods based on the ordinal patterns of the recorded series, i.e., permutation entropy (PE) and order index (OI), were introduced to characterize the complexity of the cortical activities for two groups. It was observed that the resting-state EEG of PD patients showed lower PE and higher OI than healthy controls, which indicated that the early-stage PD caused the reduced complexity of EEG. We further applied two methods to determine the complexity of EEG rhythms in five sub-bands. The results showed that the gamma, beta and alpha rhythms of PD patients were characterized by lower PE and higher OI, i.e., reduced complexity, than healthy subjects. No significant differences were observed in theta or delta rhythms between two groups. The findings suggested that PE and OI were promising methods to detect the abnormal changes in the dynamics of EEG signals associated with early-stage PD. Further, such changes in EEG complexity may be the early markers of the cortical or subcortical dysfunction caused by PD.

  15. Rehabilitation outcomes in patients with early and two-stage reconstruction of flexor tendon injuries

    PubMed Central

    Sade, Ilgin; İnanir, Murat; Şen, Suzan; Çakmak, Esra; Kablanoğlu, Serkan; Selçuk, Barin; Dursun, Nigar

    2016-01-01

    [Purpose] The primary aim of this study was to assess rehabilitation outcomes for early and two-stage repair of hand flexor tendon injuries. The secondary purpose of this study was to compare the findings between treatment groups. [Subjects and Methods] Twenty-three patients were included in this study. Early repair (n=14) and two-stage repair (n=9) groups were included in a rehabilitation program that used hand splints. This retrospective evaluated patients according to their demographic characteristics, including age, gender, injured hand, dominant hand, cause of injury, zone of injury, number of affected fingers, and accompanying injuries. Pain, range of motion, and grip strength were evaluated using a visual analog scale, goniometer, and dynamometer, respectively. [Results] Both groups showed significant improvements in pain and finger flexion after treatment compared with baseline measurements. However, no significant differences were observed between the two treatment groups. Similar results were obtained for grip strength and pinch grip, whereas gross grip was better in the early tendon repair group. [Conclusion] Early and two-stage reconstruction of patients with flexor tendon injuries can be performed with similarly favorable responses and effective rehabilitation programs. PMID:27630400

  16. The Neuroprotective Effects of Carnosine in Early Stage of Focal Ischemia Rodent Model

    PubMed Central

    Park, Hui-Seung; Han, Kyung-Hoon; Shin, Jeoung-A; Park, Joo-Hyun; Song, Kwan-Young

    2014-01-01

    Objective This study was conducted to elucidate neuroprotective effect of carnosine in early stage of stroke. Methods Early stage of rodent stroke model and neuroblastoma chemical hypoxia model was established by middle cerebral artery occlusion and antimycin A. Neuroprotective effect of carnosine was investigated with 100, 250, and 500 mg of carnosine treatment. And antioxidant expression was analyzed by enzyme linked immunosorbent assay (ELISA) and western blot in brain and blood. Results Intraperitoneal injection of 500 mg carnosine induced significant decrease of infarct volume and expansion of penumbra (p<0.05). The expression of superoxide dismutase (SOD) showed significant increase than in saline group in blood and brain (p<0.05). In the analysis of chemical hypoxia, carnosine induced increase of neuronal cell viability and decrease of reactive oxygen species (ROS) production. Conclusion Carnosine has neuroprotective property which was related to antioxidant capacity in early stage of stroke. And, the oxidative stress should be considered one of major factor in early ischemic stroke. PMID:24851146

  17. Gene expression-based biomarkers for discriminating early and late stage of clear cell renal cancer

    PubMed Central

    Bhalla, Sherry; Chaudhary, Kumardeep; Kumar, Ritesh; Sehgal, Manika; Kaur, Harpreet; Sharma, Suresh; Raghava, Gajendra P. S.

    2017-01-01

    In this study, an attempt has been made to identify expression-based gene biomarkers that can discriminate early and late stage of clear cell renal cell carcinoma (ccRCC) patients. We have analyzed the gene expression of 523 samples to identify genes that are differentially expressed in the early and late stage of ccRCC. First, a threshold-based method has been developed, which attained a maximum accuracy of 71.12% with ROC 0.67 using single gene NR3C2. To improve the performance of threshold-based method, we combined two or more genes and achieved maximum accuracy of 70.19% with ROC of 0.74 using eight genes on the validation dataset. These eight genes include four underexpressed (NR3C2, ENAM, DNASE1L3, FRMPD2) and four overexpressed (PLEKHA9, MAP6D1, SMPD4, C11orf73) genes in the late stage of ccRCC. Second, models were developed using state-of-art techniques and achieved maximum accuracy of 72.64% and 0.81 ROC using 64 genes on validation dataset. Similar accuracy was obtained on 38 genes selected from subset of genes, involved in cancer hallmark biological processes. Our analysis further implied a need to develop gender-specific models for stage classification. A web server, CancerCSP, has been developed to predict stage of ccRCC using gene expression data derived from RNAseq experiments. PMID:28349958

  18. Transcriptome profile of the early stages of breast cancer tumoral spheroids

    PubMed Central

    Pacheco-Marín, Rosario; Melendez-Zajgla, Jorge; Castillo-Rojas, Gonzalo; Mandujano-Tinoco, Edna; Garcia-Venzor, Alfredo; Uribe-Carvajal, Salvador; Cabrera-Orefice, Alfredo; Gonzalez-Torres, Carolina; Gaytan-Cervantes, Javier; Mitre-Aguilar, Irma B.; Maldonado, Vilma

    2016-01-01

    Oxygen or nutrient deprivation of early stage tumoral spheroids can be used to reliably mimic the initial growth of primary and metastatic cancer cells. However, cancer cell growth during the initial stages has not been fully explored using a genome-wide approach. Thus, in the present study, we investigated the transcriptome of breast cancer cells during the initial stages of tumoral growth using RNAseq in a model of Multicellular Tumor Spheroids (MTS). Network analyses showed that a metastatic signature was enriched as several adhesion molecules were deregulated, including EPCAM, E-cadherin, integrins and syndecans, which were further supported by an increase in cell migration. Interestingly, we also found that the cancer cells at this stage of growth exhibited a paradoxical hyperactivation of oxidative mitochondrial metabolism. In addition, we found a large number of regulated (long non coding RNA) lncRNAs, several of which were co-regulated with neighboring genes. The regulatory role of some of these lncRNAs on mRNA expression was demonstrated with gain of function assays. This is the first report of an early-stage MTS transcriptome, which not only reveals a complex expression landscape, but points toward an important contribution of long non-coding RNAs in the final phenotype of three-dimensional cellular models. PMID:27021602

  19. Alteration in successional trajectories of bacterioplankton communities in response to co-exposure of cadmium and phenanthrene in coastal water microcosms.

    PubMed

    Qian, Jie; Ding, Qifang; Guo, Annan; Zhang, Demin; Wang, Kai

    2017-02-01

    Coexistence of heavy metals and organic contaminants in coastal ecosystems may lead to complicated circumstances in ecotoxicological assessment for biological communities due to potential interactions of contaminants. Consequences of metals and polycyclic aromatic hydrocarbons (PAHs) co-contamination on coastal marine microbes at the community level were paid less attention. We chose cadmium (Cd) and phenanthrene (PHE) as representatives of metals and PAHs, respectively, and mimicked contaminations using coastal water microcosms spiked with Cd (1 mg/L), PHE (1 mg/L), and their mixture over two weeks. 16S rRNA gene amplicon sequencing was used to compare individual and cumulative effects of Cd and PHE on temporal succession of bacterioplankton communities. Although we found dramatic impacts of dimethylsulfoxide (DMSO, used as a carrier solvent for PHE) on bacterial α-diversity and composition, the individual and cumulative effects of Cd and PHE on bacterial α-diversity were temporally variable showing an antagonistic pattern at early stage in the presence of DMSO. Temporal succession of bacterial community composition (BCC) was associated with temporal variability of water physicochemical parameters, each of which explained more variation in BCC than two target contaminants did. However, Cd, PHE, and their mixture distinctly altered the successional trajectories of BCC, while only the effect of Cd was retained at the end of experiment, suggesting certain resilience in BCC after the complete dissipation of PHE along the temporal trajectory. Moreover, bacterial assemblages at the genus level associated with the target contaminants were highly time-dependent and more unpredictable in the co-contamination group, in which some genera possessing hydrocarbon-degrading members might contribute to PHE degradation. These results provide preliminary insights into how co-exposure of Cd and PHE phylogenetically alters successional trajectories of bacterioplankton communities

  20. OLD-FIELD SUCCESSIONAL DYNAMICS FOLLOWING INTENSIVE HERBIVORY

    EPA Science Inventory

    Community composition and successional patterns can be altered by disturbance and exotic species invasions. Our objective was to describe vegetation dynamics following cessation of severe disturbance, which was heavy grazing by cattle, in an old-field grassland subject to invasi...

  1. Advances in Medical Management of Early Stage and Advanced Breast Cancer: 2015.

    PubMed

    Witherby, Sabrina; Rizack, Tina; Sakr, Bachir J; Legare, Robert D; Sikov, William M

    2016-01-01

    Standard management of early stage and advanced breast cancer has been improved over the past few years by knowledge gained about the biology of the disease, results from a number of eagerly anticipated clinical trials and the development of novel agents that offer our patients options for improved outcomes or reduced toxicity or both. This review highlights recent major developments affecting the systemic therapy of breast cancer, broken down by clinically relevant patient subgroups and disease stage, and briefly discusses some of the ongoing controversies in the treatment of breast cancer and promising therapies on the horizon.

  2. Morphological and proteomic analysis of early stage of osteoblast differentiation in osteoblastic progenitor cells

    SciTech Connect

    Hong, Dun; Chen, Hai-Xiao; Yu, Hai-Qiang; Liang, Yong; Wang, Carrie; Lian, Qing-Quan; Deng, Hai-Teng; Ge, Ren-Shan

    2010-08-15

    Bone remodeling relies on a dynamic balance between bone formation and resorption, mediated by osteoblasts and osteoclasts, respectively. Under certain stimuli, osteoprogenitor cells may differentiate into premature osteoblasts and further into mature osteoblasts. This process is marked by increased alkaline phosphatase (ALP) activity and mineralized nodule formation. In this study, we induced osteoblast differentiation in mouse osteoprogenitor MC3T3-E1 cells and divided the process into three stages. In the first stage (day 3), the MC3T3-E1 cell under osteoblast differentiation did not express ALP or deposit a mineralized nodule. In the second stage, the MC3T3-E1 cell expressed ALP but did not form a mineralized nodule. In the third stage, the MC3T3-E1 cell had ALP activity and formed mineralized nodules. In the present study, we focused on morphological and proteomic changes of MC3T3-E1 cells in the early stage of osteoblast differentiation - a period when premature osteoblasts transform into mature osteoblasts. We found that mean cell area and mean stress fiber density were increased in this stage due to enhanced cell spreading and decreased cell proliferation. We further analyzed the proteins in the signaling pathway of regulation of the cytoskeleton using a proteomic approach and found upregulation of IQGAP1, gelsolin, moesin, radixin, and Cfl1. After analyzing the focal adhesion signaling pathway, we found the upregulation of FLNA, LAMA1, LAMA5, COL1A1, COL3A1, COL4A6, and COL5A2 as well as the downregulation of COL4A1, COL4A2, and COL4A4. In conclusion, the signaling pathway of regulation of the cytoskeleton and focal adhesion play critical roles in regulating cell spreading and actin skeleton formation in the early stage of osteoblast differentiation.

  3. Notch and Delta mRNAs in early-stage and mid-stage Drosophila embryos exhibit complementary patterns of protein producing potentials

    PubMed Central

    Shepherd, Andrew; Wesley, Uma; Wesley, Cedric

    2010-01-01

    Notch and Delta proteins generate Notch signaling that specifies cell fates during animal development. There is an intriguing phenomenon in Drosophila embryogenesis that has not received much attention and whose significance to embryogenesis is unknown. Notch and Delta mRNAs expressed in early-stage embryos are shorter than their counterparts in mid-stage embryos. We show here that the difference in sizes is due to mRNA 3′ processing at alternate polyadenylation sites. While the early-stage Notch mRNA has a lower protein-producing potential than the mid-stage Notch mRNA, the early-stage Delta mRNA has a higher protein-producing potential than the mid-stage Delta mRNA. Our data can explain the complementary patterns of Notch and Delta protein levels in early-stage and mid-stage embryos. Our data also raise the possibility that the manner and regulation of Notch signaling change in the course of embryogenesis and that this change is effected by 3′ UTR and mRNA 3′ processing factors. PMID:20201103

  4. [Comparative proteome analysis of blood plasma of patients with early-stage chronic cerebral ischemia].

    PubMed

    Kisrieva, Y S; Petushkova, N A; Samenkova, N F; Kuznetsova, G P; Larina, O V; Zavialova, M G; Teryaeva, N B; Belyaev, A Y; Karuzina, I I

    2016-07-01

    In the present study, we explored the technology of liquid chromatography-mass spectrometry (HPLC-MS/MS) for the proteome analysis of blood plasma of patients with early chronic cerebral ischemia. Analysis of mass-spectrometer data carried out in automatic mode using the software Progenesis LS-MS. As a result of this study identified 43 proteins. The differences identified in the study group compared with the control in 7 proteins. It was found that in the early stages of chronic cerebral ischemia proteome changes in blood plasma affect proteins related to the immune system, the system for the maintenance of hemostasis and lipid metabolism.

  5. A functional account of verb use in the early stages of English multiword development.

    PubMed

    Cameron-Faulkner, Thea

    2012-09-01

    The present study investigates flexibility of verb use in the early stages of English multiword development, and its relationship with patterns attested in the input. The data is taken from a case study of a monolingual English-speaking boy aged 2 ; 5-2 ; 9 and his mother while engaged in daily activities in the home. Data were coded according to Halliday's (1975) functional system. The findings suggest that early multiword verb use is functionally restricted and closely tied to verb use in the input.

  6. Early stages of development of the Taenia solium metacestode in pigs.

    PubMed

    Garrido, Gerardo Salas; de Aluja, Aline S; Casas, Fernando Constantino

    2007-04-01

    In order to identify the early stages of Taenia solium metacestodes, 12 pigs were each fed 100,000 viable eggs and later killed and necropsied at different times after infection. Hematoxylin-eosin (HE) and immunohistochemical techniques (IHCs) were used to identify onchospheres and cysticerci in different tissues. At 2 days postinfection (dpi) structures compatible with onchospheres were found in the lumen of the small intestine, and in the mesenteric blood vessels and lymph nodes. At 4 dpi, these same structures were observed in the small intestine, the liver, and skeletal muscles. Between 6 and 39 dpi, they were found only in skeletal muscles. Between 2 and 6 dpi the postonchospheres were circular and oval shaped and measured between 6 and 34 x 27 microm. From 14 to 39 dpi, well-developed metacestodes 550 x 750 microm were observed. IHCs support the identification of early stages of T. solium.

  7. Early Stages of De Novo Designed Beta-Hairpin Peptide Self-Assembly

    NASA Astrophysics Data System (ADS)

    Yucel, Tuna; Schneider, Joel P.; Pochan, Darrin J.

    2007-03-01

    In aqueous solution, MAX 1 peptide is unfolded and does not self-assemble. The peptide intramolecularly folds into a beta-hairpin when the electrostatic interactions between charged residues are screened through increasing the ionic strength at neutral pH. Beta-hairpin molecules supramolecularly assemble via hydrophobic collapse and hydrogen bonding into a 3-D hydrogel network. By combining the results of CD, cryo-TEM, DLS, and oscillatory rheology, we understand that the self-assembly proceeds by nucleation of monodisperse (3 nm wide) beta-sheet fibrils, which elongate, branch and cross-link to form clusters of fibrils. Assembly kinetics at this early stage indicates power law growth with assembly time. Eventually, clusters of fibrils interpenetrate to form a percolated network, as evidenced by the increasing network rigidity. The early stage assembly process will be discussed and compared to published gelation models.

  8. Turning visual shapes into sounds: early stages of reading acquisition revealed in the ventral occipitotemporal cortex.

    PubMed

    Perrone-Bertolotti, M; Vidal, J R; de Palma, L; Hamamé, C M; Ossandon, T; Kahane, P; Minotti, L; Bertrand, O; Lachaux, J-P

    2014-04-15

    The exact role of the left ventral occipitotemporal cortex (VOTC) during the initial stages of reading acquisition is a hotly debated issue, especially regarding the comparative effect of learning on early stimulus-dependent vs. later task-dependent processes. We show that this controversy can be solved with high-temporal resolution intracerebral EEG recordings of the VOTC. We measured High-Frequency Activity (50-150 Hz) as a proxy of population-level spiking activity while participants learned Japanese Katakana symbols, and found that learning primarily affects top-down/task-dependent neural processing, after a few minutes only. In contrast, adaptation of early bottom-up/stimulus-dependent processing takes several days to adapt and provides the basis for fluent reading. Such evidence that two consecutive stages of neural processing, stimulus- and task-dependent are differentially affected by learning, can reconcile seemingly opposite hypotheses on the role of the VOTC during reading acquisition.

  9. Nerve growth factor regulates axial rotation during early stages of chick embryo development.

    PubMed

    Manca, Annalisa; Capsoni, Simona; Di Luzio, Anna; Vignone, Domenico; Malerba, Francesca; Paoletti, Francesca; Brandi, Rossella; Arisi, Ivan; Cattaneo, Antonino; Levi-Montalcini, Rita

    2012-02-07

    Nerve growth factor (NGF) was discovered because of its neurotrophic actions on sympathetic and sensory neurons in the developing chicken embryo. NGF was subsequently found to influence and regulate the function of many neuronal and non neuronal cells in adult organisms. Little is known, however, about the possible actions of NGF during early embryonic stages. However, mRNAs encoding for NGF and its receptors TrkA and p75(NTR) are expressed at very early stages of avian embryo development, before the nervous system is formed. The question, therefore, arises as to what might be the functions of NGF in early chicken embryo development, before its well-established actions on the developing sympathetic and sensory neurons. To investigate possible roles of NGF in the earliest stages of development, stage HH 11-12 chicken embryos were injected with an anti-NGF antibody (mAb αD11) that binds mature NGF with high affinity. Treatment with anti-NGF, but not with a control antibody, led to a dose-dependent inversion of the direction of axial rotation. This effect of altered rotation after anti NGF injection was associated with an increased cell death in somites. Concurrently, a microarray mRNA expression analysis revealed that NGF neutralization affects the expression of genes linked to the regulation of development or cell proliferation. These results reveal a role for NGF in early chicken embryo development and, in particular, in the regulation of somite survival and axial rotation, a crucial developmental process linked to left-right asymmetry specification.

  10. Comparison of Favorable Early-Stage Hodgkin's Lymphoma Treatments: A Single-Institution Review

    SciTech Connect

    Samant, Rajiv; Alomary, Ibraheem; Alsaeed, Eyad; Al-jasir, Badr; Bence-Bruckler, Isabelle; Cross, Peter; Genest, Paul; Huebsch, Lothar

    2010-03-15

    Purpose: To compare outcomes of patients receiving combined-modality chemotherapy and radiation (CMT) vs. other approaches for early-stage Hodgkin's lymphoma (HL). Methods and Materials: A review of patients with nonbulky, early-stage (IA/IIA) HL treated between 1984 and 2002 was performed to determine the treatment approaches used and the outcomes obtained. Results: There were 173 adult patients with newly diagnosed early-stage HL (49% men, 51% women, median age 33 [range 17-82] years). Treatment was as follows: extended-field radiotherapy alone (EFRT) 49%; chemotherapy alone (CTA) 13%; and CMT 38%. Among CMT patients, 36% received abbreviated doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy (three to four cycles) followed by involved-field radiotherapy. With a median follow-up of 8.3 years, the estimated 10-year relapse-free survival (RFS) and overall survival (OS) rates for the entire cohort were 78% and 85%, respectively. The 10-year RFS and OS rates for the various groups were as follows: 69% and 81% for EFRT; 78% and 84% for CTA; and 87% and 89% for CMT. The 10-year RFS rate was significantly higher (p < 0.01) among CMT patients. The use of EFRT has diminished from approximately 90% in the 1980s to virtually no use at present, whereas the use of CTA and CMT has increased significantly (p < 0.01). Conclusion: Early-stage HL treatment has changed dramatically over the past 2 decades, and our results support the superiority and continued use of CMT, specifically abbreviated-course chemotherapy and involved-field radiotherapy, as an appropriate treatment approach.

  11. Varying postresection lactate dehydrogenase with overall survival of early stage pancreatic cancer patients

    PubMed Central

    Xiao, Yuanyuan; Xie, Zhihui; Shao, Zhenyi; Chen, Wen; Xie, Hua; Qin, Guoyou; Zhao, Naiqing

    2017-01-01

    Abstract Several previously published studies revealed a hazardous role of pretreatment lactate dehydrogenase (LDH) in survival of advanced or metastatic pancreatic cancer (PC) patients. Nevertheless, in early stage PC patients who are eligible for curative resection, the prognostic role of postresection LDH has never been discussed. In this study, we aimed to explore the prognostic significance of varying postresection LDH among early stage PC patients. In total, 80 PC patients who received curative resection were retrospectively selected from a population-based electronic inpatients database which originated from Shanghai, China. A dynamic survival analysis method, counting process approach in combination with the multiple failure-time Cox model, was applied to evaluate the association between postresection LDH and OS. The multiple failure-time Cox model found that age, resection modality, and postresection LDH were significantly associated with OS: an elevated LDH (defined as > 250 U/L) was related to 2.93 (95% CI: 1.26–6.79) folds of death hazard. Further analysis disclosed an identifiable dose–response association between LDH and OS: compared with LDH≤155 U/L, the HRs for 155 U/L < LDH < 196 U/L, and LDH≥196 U/L were 2.07 (95% CI: 0.88–4.88) and 3.15 (95% CI: 1.30–7.59), respectively. Our study results suggest that postresection LDH is a prominent prognostic factor in this group of early stage PC patients. Maintaining normally ranged LDH after resection might bring about survival benefit in early stage PC patients. PMID:28328834

  12. Varying postresection lactate dehydrogenase with overall survival of early stage pancreatic cancer patients: A retrospective study.

    PubMed

    Xiao, Yuanyuan; Xie, Zhihui; Shao, Zhenyi; Chen, Wen; Xie, Hua; Qin, Guoyou; Zhao, Naiqing

    2017-03-01

    Several previously published studies revealed a hazardous role of pretreatment lactate dehydrogenase (LDH) in survival of advanced or metastatic pancreatic cancer (PC) patients. Nevertheless, in early stage PC patients who are eligible for curative resection, the prognostic role of postresection LDH has never been discussed. In this study, we aimed to explore the prognostic significance of varying postresection LDH among early stage PC patients. In total, 80 PC patients who received curative resection were retrospectively selected from a population-based electronic inpatients database which originated from Shanghai, China. A dynamic survival analysis method, counting process approach in combination with the multiple failure-time Cox model, was applied to evaluate the association between postresection LDH and OS. The multiple failure-time Cox model found that age, resection modality, and postresection LDH were significantly associated with OS: an elevated LDH (defined as > 250 U/L) was related to 2.93 (95% CI: 1.26-6.79) folds of death hazard. Further analysis disclosed an identifiable dose-response association between LDH and OS: compared with LDH≤155 U/L, the HRs for 155 U/L < LDH < 196 U/L, and LDH≥196 U/L were 2.07 (95% CI: 0.88-4.88) and 3.15 (95% CI: 1.30-7.59), respectively. Our study results suggest that postresection LDH is a prominent prognostic factor in this group of early stage PC patients. Maintaining normally ranged LDH after resection might bring about survival benefit in early stage PC patients.

  13. Gadolinium metallo nanocongregates as potential magnetosensors for detecting early stage cancers

    SciTech Connect

    Dutta, Ranu; Pandey, Avinash C.

    2015-04-27

    Gadolinium chelates and gadolinium based inorganic nanoparticles have been extensively studied, because of the high magnetic moment of gadolinium. Here, metallic gadolinium nanocongregates have been developed. Upon injecting these nanoparticles in the mice, they initially circulate in the blood stream and are localized at the cancer site, which could be visualized upon application of magnetic field hence acting as small magnetic nanosensors searching for even small cancers, detecting cancers at a very early stage.

  14. Early Stages of Figure–Ground Segregation during Perception of the Face–Vase

    PubMed Central

    Pitts, Michael A.; Martínez, Antígona; Brewer, James B.; Hillyard, Steven A.

    2011-01-01

    The temporal sequence of neural processes supporting figure–ground perception was investigated by recording ERPs associated with subjects’ perceptions of the face–vase figure. In Experiment 1, subjects continuously reported whether they perceived the face or the vase as the foreground figure by pressing one of two buttons. Each button press triggered a probe flash to the face region, the vase region, or the borders between the two. The N170/vertex positive potential (VPP) component of the ERP elicited by probes to the face region was larger when subjects perceived the faces as figure. Preceding the N170/VPP, two additional components were identified. First, when the borders were probed, ERPs differed in amplitude as early as 110 msec after probe onset depending on subjects’ figure–ground perceptions. Second, when the face or vase regions were probed, ERPs were more positive (at ~150–200 msec) when that region was perceived as figure versus background. These components likely reflect an early “border ownership” stage, and a subsequent “figure–ground segregation” stage of processing. To explore the influence of attention on these stages of processing, two additional experiments were conducted. In Experiment 2, subjects selectively attended to the face or vase region, and the same early ERP components were again produced. In Experiment 3, subjects performed an identical selective attention task, but on a display lacking distinctive figure–ground borders, and neither of the early components were produced. Results from these experiments suggest sequential stages of processing underlying figure–ground perception, each which are subject to modifications by selective attention. PMID:20146604

  15. DNA Copy Number Signature to Predict Recurrence in Early-Stage Ovarian Cancer

    DTIC Science & Technology

    2015-08-01

    and select 330 samples for CNV analysis. Months :1 - 2 • Subtask 2 Prepare sections (10 μm) for microdissection to ensure>80% tumor. Months 3 - 8...Subtask 3 DNA preparation from microdissected specimens. Months 3 - 8 Major Task 2: To determine the copy number gain and loss for early stage high...to prepare chip compatible samples. Months : 9 - 18 • Subtask 2 Genomic abnormality analysis by IlluminaHumanOmniExpress-FFPE BeadChip system. Months

  16. Development of a Smart Diagnostics Platform for Early-Stage Screening of Breast Cancer

    DTIC Science & Technology

    2007-04-01

    thereby establishing non-invasive avenues for screening. The bioindicators that we are targeting are apolar metabolites indicative of early-stage...also yields the potential for part-per-million sensitivity. The current methods used to analyze bioindicators in urine and breath include high...Simulations Chemical Characterization NMR, FTIR, MS II. Preparation of Switchable Surfaces III. Testing Binding of Model Bioindicators 1. Self-Assembly

  17. [Signal exchange between plants and Arbuscular Mycorrhizae fungi during the early stage of symbiosis - A review].

    PubMed

    Duan, Qianqian; Yang, Xiaohong; Huang, Xianzhi

    2015-07-04

    Much is known about Arbuscular Mycorrhizae (AM), an important component of the ecosystem, whereas little is known about the signal exchange that allows mutual recognition and reprograming for the anticipated physical interaction. This review addresses the latest advances of signal exchange between plants and AM, including signal substances and their function, related genes and regulation function in the early stage of plant-fungal symbiosis.

  18. Evaluating the Significance of Viscoelasticity in Diagnosing Early-Stage Liver Fibrosis with Transient Elastography

    PubMed Central

    Cheng, Jun; He, Qiong; Luo, Jianwen; Yang, Xueping; Shao, Jinhua; Xing, Huichun

    2017-01-01

    Transient elastography quantifies the propagation of a mechanically generated shear wave within a soft tissue, which can be used to characterize the elasticity and viscosity parameters of the tissue. The aim of our study was to combine numerical simulation and clinical assessment to define a viscoelastic index of liver tissue to improve the quality of early diagnosis of liver fibrosis. This is clinically relevant, as early fibrosis is reversible. We developed an idealized two-dimensional axisymmetric finite element model of the liver to evaluate the effects of different viscoelastic values on the propagation characteristics of the shear wave. The diagnostic value of the identified viscoelastic index was verified against the clinical data of 99 patients who had undergone biopsy and routine blood tests for staging of liver disease resulting from chronic hepatitis B infection. Liver stiffness measurement (LSM) and the shear wave attenuation fitting coefficient (AFC) were calculated from the ultrasound data obtained by performing transient elastography. Receiver operating curve analysis was used to evaluate the reliability and diagnostic accuracy of LSM and AFC. Compared to LSM, the AFC provided a higher diagnostic accuracy to differentiate early stages of liver fibrosis, namely F1 and F2 stages, with an overall specificity of 81.48%, sensitivity of 83.33% and diagnostic accuracy of 81.82%. AFC was influenced by the level of LSM, ALT. However, there are no correlation between AFC and Age, BMI, TBIL or DBIL. Quantification of the viscoelasticity of liver tissue provides reliable measurement to identify and differentiate early stages of liver fibrosis. PMID:28107385

  19. Atrophy patterns in early clinical stages across distinct phenotypes of Alzheimer's disease.

    PubMed

    Ossenkoppele, Rik; Cohn-Sheehy, Brendan I; La Joie, Renaud; Vogel, Jacob W; Möller, Christiane; Lehmann, Manja; van Berckel, Bart N M; Seeley, William W; Pijnenburg, Yolande A; Gorno-Tempini, Maria L; Kramer, Joel H; Barkhof, Frederik; Rosen, Howard J; van der Flier, Wiesje M; Jagust, William J; Miller, Bruce L; Scheltens, Philip; Rabinovici, Gil D

    2015-11-01

    Alzheimer's disease (AD) can present with distinct clinical variants. Identifying the earliest neurodegenerative changes associated with each variant has implications for early diagnosis, and for understanding the mechanisms that underlie regional vulnerability and disease progression in AD. We performed voxel-based morphometry to detect atrophy patterns in early clinical stages of four AD phenotypes: Posterior cortical atrophy (PCA, "visual variant," n=93), logopenic variant primary progressive aphasia (lvPPA, "language variant," n=74), and memory-predominant AD categorized as early age-of-onset (EOAD, <65 years, n=114) and late age-of-onset (LOAD, >65 years, n=114). Patients with each syndrome were stratified based on: (1) degree of functional impairment, as measured by the clinical dementia rating (CDR) scale, and (2) overall extent of brain atrophy, as measured by a neuroimaging approach that sums the number of brain voxels showing significantly lower gray matter volume than cognitively normal controls (n=80). Even at the earliest clinical stage (CDR=0.5 or bottom quartile of overall atrophy), patients with each syndrome showed both common and variant-specific atrophy. Common atrophy across variants was found in temporoparietal regions that comprise the posterior default mode network (DMN). Early syndrome-specific atrophy mirrored functional brain networks underlying functions that are uniquely affected in each variant: Language network in lvPPA, posterior cingulate cortex-hippocampal circuit in amnestic EOAD and LOAD, and visual networks in PCA. At more advanced stages, atrophy patterns largely converged across AD variants. These findings support a model in which neurodegeneration selectively targets both the DMN and syndrome-specific vulnerable networks at the earliest clinical stages of AD.

  20. Proteomic Analysis of Phosphoproteins in the Rice Nucleus During the Early Stage of Seed Germination.

    PubMed

    Li, Ming; Yin, Xiaojian; Sakata, Katsumi; Yang, Pingfang; Komatsu, Setsuko

    2015-07-02

    The early stage of seed germination is the first step in the plant life cycle without visible morphological change. To investigate the mechanism controlling the early stage of rice seed germination, we performed gel-and label-free nuclear phosphoproteomics. A total of 3467 phosphopeptides belonging to 102 nuclear phosphoproteins from rice embryos were identified. Protein-synthesis-related proteins were mainly phosphorylated. During the first 24 h following imbibition, 115 nuclear phosphoproteins were identified, and significant changes in the phosphorylation level over time were observed in 29 phosphoproteins. Cluster analysis indicated that nucleotide-binding proteins and zinc finger CCCH- and BED-type proteins increased in abundance during the first 12 h of imbibition and then decreased. The in silico protein-protein interactions for 29 nuclear phosphoproteins indicated that the Sas10/Utp3 protein, which functions in snoRNA binding and gene silencing, was the center of the phosphoprotein network in nuclei. The germination rate of seeds was significantly slowed with phosphatase inhibitor treatment. The mRNA expression of the zinc finger CCCH-type protein did not change, and the zinc finger BED-type protein was upregulated in rice embryos during the early stage of germination with phosphatase inhibitor treatment. These results suggest that the phosphorylation and dephosphorylation of nuclear proteins are involved in rice seed germination. Furthermore, transcription factors such as zinc finger CCCH- and BED-type proteins might play a key role through nuclear phosphoproteins, and Sas10/Utp3 protein might interact with nuclear phosphoproteins in rice embryos to mediate the early stage of seed germination.

  1. Early stages of figure-ground segregation during perception of the face-vase.

    PubMed

    Pitts, Michael A; Martínez, Antígona; Brewer, James B; Hillyard, Steven A

    2011-04-01

    The temporal sequence of neural processes supporting figure-ground perception was investigated by recording ERPs associated with subjects' perceptions of the face-vase figure. In Experiment 1, subjects continuously reported whether they perceived the face or the vase as the foreground figure by pressing one of two buttons. Each button press triggered a probe flash to the face region, the vase region, or the borders between the two. The N170/vertex positive potential (VPP) component of the ERP elicited by probes to the face region was larger when subjects perceived the faces as figure. Preceding the N170/VPP, two additional components were identified. First, when the borders were probed, ERPs differed in amplitude as early as 110 msec after probe onset depending on subjects' figure-ground perceptions. Second, when the face or vase regions were probed, ERPs were more positive (at ∼ 150-200 msec) when that region was perceived as figure versus background. These components likely reflect an early "border ownership" stage, and a subsequent "figure-ground segregation" stage of processing. To explore the influence of attention on these stages of processing, two additional experiments were conducted. In Experiment 2, subjects selectively attended to the face or vase region, and the same early ERP components were again produced. In Experiment 3, subjects performed an identical selective attention task, but on a display lacking distinctive figure-ground borders, and neither of the early components were produced. Results from these experiments suggest sequential stages of processing underlying figure-ground perception, each which are subject to modifications by selective attention.

  2. Clinical and dosimetric implications of intensity-modulated radiotherapy for early-stage glottic carcinoma

    SciTech Connect

    Ward, Matthew Christopher Pham, Yvonne D.; Kotecha, Rupesh; Zakem, Sara J.; Murray, Eric; Greskovich, John F.

    2016-04-01

    Conventional parallel-opposed radiotherapy (PORT) is the established standard technique for early-stage glottic carcinoma. However, case reports have reported the utility of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) with or without image guidance (image-guided radiotherapy, IGRT) in select patients. The proposed advantages of IMRT/VMAT include sparing of the carotid artery, thyroid gland, and the remaining functional larynx, although these benefits remain unclear. The following case study presents a patient with multiple vascular comorbidities treated with VMAT for early-stage glottic carcinoma. A detailed explanation of the corresponding treatment details, dose-volume histogram (DVH) analysis, and a review of the relevant literature are provided. Conventional PORT remains the standard of care for early-stage glottic carcinoma. IMRT or VMAT may be beneficial for select patients, although great care is necessary to avoid a geographical miss. Clinical data supporting the benefit of CRT are lacking. Therefore, these techniques should be used with caution and only in selected patients.

  3. Promoting Quality and Evidence-Based Care in Early-Stage Breast Cancer Follow-up

    PubMed Central

    Hayes, Daniel F.; Ramsey, Scott D.; Hortobagyi, Gabriel N.; Barlow, William E.; Gralow, Julie R.

    2014-01-01

    Evidence-based guidelines for long-term follow-up of early-stage breast cancer patients developed by oncology societies in the United States and Europe recommend that breast cancer survivors undergo regular evaluation with history and physical examination, as well as annual mammography. Routine blood tests, circulating tumor markers, and/or surveillance imaging studies beyond mammography are not recommended in the absence of concerning symptoms or physical examination findings because of lack of supportive clinical evidence. Despite these guidelines, studies have shown that 20% to 40% of oncologists assess serum tumor markers as part of routine monitoring of early-stage breast cancer patients. As part of efforts to both address the financial challenges confronting the health-care system and optimize patient outcomes, the American Society of Clinical Oncology’s Cost of Care Task Force identified adherence to breast cancer surveillance guidelines as an opportunity to improve care and reduce cost. However, these recommendations are based on trials done in an era of outdated technology and limited therapeutic options. It is possible that recent improvements in diagnostics and treatments could make earlier detection of recurrent disease important for improving both survival and quality of life outcomes. Research is necessary to further inform optimal breast cancer follow-up strategies, which could impact these recommendations. At this time, outside of well-conducted clinical trials, there is no role for ordering routine serial blood or imaging tests in monitoring for recurrence in early-stage breast cancer patients. PMID:24627271

  4. Two-stage biomarker panel study and estimation allowing early termination for futility.

    PubMed

    Zhao, Shanshan; Zheng, Yingye; Prentice, Ross L; Feng, Ziding

    2015-10-01

    Technological advances have yielded a wealth of biomarkers that have the potential to detect chronic diseases such as cancer. However, most biomarkers considered for further validation turn out not to have strong enough performance to be used in clinical practice. Group sequential designs that allow early termination for futility may be cost-effective for biomarker studies based on biobanks of stored specimens. Previous studies proposed a group sequential design for the validation of a single biomarker. In this article, we adapt a 2-stage design to the setting where a panel of candidate biomarkers are under investigation. Conditional estimators of the clinical performance are proposed under an updated risk model that uses all accrued data, and can be computed through resampling procedures. Under a special case where a multivariate binormal distribution applies for biomarkers following a suitable transformation, these estimators have analytical forms, alleviating the computational burden while retaining statistical efficiency. Performance of the proposed 2-stage design and estimators are compared with a traditional fixed-sample design and an existing 2-stage design that allows early termination but does not update the risk model with accrued information. Our proposed design and estimators show an ability to reduce sample size when the biomarker panel is not promising, while controlling rejection rate and gaining efficiency when the panel is promising. We apply the proposed methods to a biomarker panel development for the detection of high-grade prostate cancer in a study conducted within the National Cancer Institute's Early Detection Research Network.

  5. Promoting emancipated decision-making for surgical treatment of early stage breast cancer among Jordanian women

    PubMed Central

    Obeidat, Rana F.

    2015-01-01

    To use the critical social theory as a framework to analyze the oppression of Jordanian women with early stage breast cancer in the decision-making process for surgical treatment and suggest strategies to emancipate these women to make free choices. This is a discussion paper utilizing the critical social theory as a framework for analysis. The sexist and paternalistic ideology that characterizes Jordanian society in general and the medical establishment in particular as well as the biomedical ideology are some of the responsible ideologies for the fact that many Jordanian women with early stage breast cancer are denied the right to choose a surgical treatment according to their own preferences and values. The financial and political power of Jordanian medical organizations (e.g., Jordan Medical Council), the weakness of nursing administration in the healthcare system, and the hierarchical organization of Jordanian society, where men are first and women are second, support these oppressing ideologies. Knowledge is a strong tool of power. Jordanian nurses could empower women with early stage breast cancer by enhancing their knowledge regarding their health and the options available for surgical treatment. To successfully emancipate patients, education alone may not be enough; there is also a need for health care providers’ support and unconditional acceptance of choice. To achieve the aim of emancipating women with breast cancer from the oppression inherent in the persistence of mastectomy, Jordanian nurses need to recognize that they should first gain greater power and authority in the healthcare system. PMID:27981122

  6. The use of adjuvant bisphophonates in the treatment of early-stage breast cancer.

    PubMed

    Mathew, Aju; Brufsky, Adam M

    2014-11-01

    Adjuvant treatment of breast cancer has resulted in significant improvement in breast cancer-related outcomes. In addition to chemotherapy and endocrine therapy, the bone-protective agents known as bisphosphonates have been extensively investigated for their putative antitumor effect. Backed by strong preclinical data from in vitro and in vivo models, several randomized clinical trials have evaluated the role of bisphosphonates in an adjuvant setting. The recent NSABP B-34 (National Surgical Adjuvant Breast and Bowel Project protocol B-34) and AZURE (Adjuvant Zoledronic Acid to Reduce Recurrence) studies found no disease-free survival benefit with clodronate and zoledronate, respectively, whereas the ABCSG-12 (Austrian Breast and Colorectal Cancer Study Group trial 12) study found improvement in disease-free survival with zoledronate. Data from these trials suggested a beneficial effect of bisphosphonates in older, postmenopausal women and in premenopausal women treated with ovarian suppression. Given the acceptable toxicity profile of bisphosphonates, these agents could be a useful adjunct to adjuvant chemotherapy or endocrine treatment for early-stage breast cancer in a carefully selected subset of patients. This review aims to critically synthesize the results of clinical trials of adjuvant bisphosphonates in early-stage breast cancer, and to provide guidelines for the use of these agents in early-stage breast cancer.

  7. Promoting emancipated decision-making for surgical treatment of early stage breast cancer among Jordanian women.

    PubMed

    Obeidat, Rana F

    2015-01-01

    To use the critical social theory as a framework to analyze the oppression of Jordanian women with early stage breast cancer in the decision-making process for surgical treatment and suggest strategies to emancipate these women to make free choices. This is a discussion paper utilizing the critical social theory as a framework for analysis. The sexist and paternalistic ideology that characterizes Jordanian society in general and the medical establishment in particular as well as the biomedical ideology are some of the responsible ideologies for the fact that many Jordanian women with early stage breast cancer are denied the right to choose a surgical treatment according to their own preferences and values. The financial and political power of Jordanian medical organizations (e.g., Jordan Medical Council), the weakness of nursing administration in the healthcare system, and the hierarchical organization of Jordanian society, where men are first and women are second, support these oppressing ideologies. Knowledge is a strong tool of power. Jordanian nurses could empower women with early stage breast cancer by enhancing their knowledge regarding their health and the options available for surgical treatment. To successfully emancipate patients, education alone may not be enough; there is also a need for health care providers' support and unconditional acceptance of choice. To achieve the aim of emancipating women with breast cancer from the oppression inherent in the persistence of mastectomy, Jordanian nurses need to recognize that they should first gain greater power and authority in the healthcare system.

  8. Neurophysiological Evidence of Compensatory Brain Mechanisms in Early-Stage Multiple Sclerosis

    PubMed Central

    López-Góngora, Mariana; Escartín, Antonio; Martínez-Horta, Saul; Fernández-Bobadilla, Ramón; Querol, Luis; Romero, Sergio; Mañanas, Miquel Àngel; Riba, Jordi

    2015-01-01

    Multiple sclerosis (MS) is a chronic central nervous system disorder characterized by white matter inflammation, demyelination and neurodegeneration. Although cognitive dysfunction is a common manifestation, it may go unnoticed in recently-diagnosed patients. Prior studies suggest MS patients develop compensatory mechanisms potentially involving enhanced performance monitoring. Here we assessed the performance monitoring system in early-stage MS patients using the error-related negativity (ERN), an event-related brain potential (ERP) observed following behavioral errors. Twenty-seven early-stage MS patients and 31 controls were neuropsychologically assessed. Electroencephalography recordings were obtained while participants performed: a) a stop task and b) an auditory oddball task. Behavior and ERP measures were assessed. No differences in performance were found between groups in most neuropsychological tests or in behavior or ERP components in the auditory oddball task. However, the amplitude of the ERN associated with stop errors in the stop task was significantly higher in patients. ERN amplitude correlated positively with scores on the Expanded Disability Status Scale and the Multiple Sclerosis Severity Score, and negatively with the time since last relapse. Patients showed higher neuronal recruitment in tasks involving performance monitoring. Results suggest the development of compensatory brain mechanisms in early-stage MS and reflect the sensitivity of the ERN to detect these changes. PMID:26322632

  9. Effects of Columbia River water on early life-stages of white sturgeon (Acipenser transmontanus).

    PubMed

    Tompsett, Amber R; Vardy, David W; Higley, Eric; Doering, Jon A; Allan, Marcie; Liber, Karsten; Giesy, John P; Hecker, Markus

    2014-03-01

    The white sturgeon (Acipenser transmontanus) population that resides in the Columbia River in British Columbia (BC), Canada, has suffered recruitment failures for more than three decades. During the summers of 2008 and 2009, studies were performed to determine whether exposure to water downstream of a metal smelter in Trail, BC affected survival or growth of early life-stages of white sturgeon through 60+ days post-fertilization (dpf). In both years, there were no significant differences in survival of fish that were exposed to water from downstream compared to water from upstream of the smelter. At 20-21dpf, average mortality was 2.4 percent and 12 percent in upstream water for 2008 and 2009, respectively, which was similar to the average mortality of 3.8 percent and 7.2 percent in downstream water for 2008 and 2009, respectively. Relatively great mortality after 20-21dpf complicated analysis of the subchronic exposure, but use of a survival analysis indicated that the average fish died at 25-29dpf, regardless of whether the water to which they were exposed came from upstream or downstream of the smelter. In addition, measured concentrations of metals in river water were less than the threshold for adverse effects on early life stages of white sturgeon. Based upon these analyses, it is not likely that current concentrations of metals in the Columbia River in southern BC are adversely affecting survival of early life stages of white sturgeon larvae.

  10. On the role of extracellular polymeric substances during early stages of Xylella fastidiosa biofilm formation.

    PubMed

    Lorite, Gabriela S; de Souza, Alessandra A; Neubauer, Daniel; Mizaikoff, Boris; Kranz, Christine; Cotta, Mônica A

    2013-02-01

    The structural integrity and protection of bacterial biofilms are intrinsically associated with a matrix of extracellular polymeric substances (EPS) produced by the bacteria cells. However, the role of these substances during biofilm adhesion to a surface remains largely unclear. In this study, the influence of EPS on Xylella fastidiosa biofilm formation was investigated. This bacterium is associated with economically important plant diseases; it presents a slow growth rate and thus allows us to pinpoint more precisely the early stages of cell-surface adhesion. Scanning electron microscopy and atomic force microscopy show evidence of EPS production in such early stages and around individual bacteria cells attached to the substrate surface even a few hours after inoculation. In addition, EPS formation was investigated via attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR). To this end, X. fastidiosa cells were inoculated within an ATR liquid cell assembly. IR-ATR spectra clearly reveal EPS formation already during the early stages of X. fastidiosa biofilm formation, thereby providing supporting evidence for the hypothesis of the relevance of the EPS contribution to the adhesion process.

  11. Systemic Therapy for Early-Stage Breast Cancer: What the Plastic Surgeon Should Know.

    PubMed

    Teven, Chad M; Schmid, Daniel B; Sisco, Mark; Ward, James; Howard, Michael A

    2017-01-01

    Objective: We review the types, indications, and common regimens of systemic forms of therapy offered in early-stage breast cancer. We further detail the mechanism of action, approved uses, major toxicities, and relevance to breast reconstruction of specific agents. Methods: A review of the literature on PubMed and Cochrane databases was undertaken to define the indications and common regimens of systemic therapy in early-stage breast cancer. In addition, literature describing relevant information regarding specific systemic agents was reviewed. Results: The main objectives of systemic therapy, when provided in the perioperative setting, are to reduce the risk for future recurrence and prolong overall survival. Systemic forms of therapy consist of chemotherapy, hormonal therapy, and targeted therapy and are increasingly being offered to women with early-stage breast cancer. Similarly, as more women are diagnosed with disease that is amenable to surgical extirpation, rates of breast reconstruction are on the rise. Many agents have effects that may impact patient safety with respect to breast reconstruction. Conclusions: Increasingly, women with breast cancer receive 1 or more forms of systemic therapy during the course of their treatment. It is therefore of significant importance that plastic surgeons have a clear understanding of the issues surrounding the use of systemic agents.

  12. Systemic Therapy for Early-Stage Breast Cancer: What the Plastic Surgeon Should Know

    PubMed Central

    Teven, Chad M.; Schmid, Daniel B.; Sisco, Mark; Ward, James

    2017-01-01

    Objective: We review the types, indications, and common regimens of systemic forms of therapy offered in early-stage breast cancer. We further detail the mechanism of action, approved uses, major toxicities, and relevance to breast reconstruction of specific agents. Methods: A review of the literature on PubMed and Cochrane databases was undertaken to define the indications and common regimens of systemic therapy in early-stage breast cancer. In addition, literature describing relevant information regarding specific systemic agents was reviewed. Results: The main objectives of systemic therapy, when provided in the perioperative setting, are to reduce the risk for future recurrence and prolong overall survival. Systemic forms of therapy consist of chemotherapy, hormonal therapy, and targeted therapy and are increasingly being offered to women with early-stage breast cancer. Similarly, as more women are diagnosed with disease that is amenable to surgical extirpation, rates of breast reconstruction are on the rise. Many agents have effects that may impact patient safety with respect to breast reconstruction. Conclusions: Increasingly, women with breast cancer receive 1 or more forms of systemic therapy during the course of their treatment. It is therefore of significant importance that plastic surgeons have a clear understanding of the issues surrounding the use of systemic agents. PMID:28293332

  13. Hypokinesia of associated movement in Parkinson's disease: a symptom in early stages of the disease.

    PubMed

    Hoshiyama, M; Kaneoke, Y; Koike, Y; Takahashi, A; Watanabe, S

    1994-08-01

    We compared the degrees of impairment between intended voluntary movement and its simultaneous automatic associated movement in Parkinson's disease (PD). We studied wrist dorsiflexion as a movement associated with grip in 20 patients with PD and in 20 normal controls. The patients showed a significantly smaller dorsiflexion as compared with the controls. The decrease in associated movement was related to the severity of clinical stage of the disease, while gripping was performed well in each stage. The temporal relationship between grip and associated movement was the same for both groups of subjects. The patients showed no disturbance of amplitude or velocity for a single motor act of wrist dorsiflexion. Persons with PD have a greater reduction of automatic associated movement than intended voluntary movement. This may be one of the bases of clinical symptoms of PD patients in early stages of the disease.

  14. Treatment of early stage breast cancer by limited surgery and radical irradiation

    SciTech Connect

    Chu, A.M.; Cope, O.; Russo, R.; Wang, C.C.; Schulz, M.D.; Wang, C.; Rodkey, G.

    1980-01-01

    Eighty-five female patients with early stage breast cancer, i.e., Stage I and II were treated by limited surgery followed by radical radiation therapy at Massachusetts General Hospital between January, 1956 and December, 1974. Patients included those who were medically inoperable or who refused mastectomy. The 5-year survival rate was 83% and 76% for Stage I and II, respectively. The corresponding disease free survival (absolute) was 67% and 42%. Although the number of patients so treated is small, there was no significant difference in survival from the results of the radical mastectomy series at the same institution. No major complications were encountered. Seventeen of eighty-five patients developed minor problems; mostly fibrosis and minimal arm lymphedema stemmming from older orthovoltage equipment and treatment techniques. With the current availability of megavoltage equipment, improvements in techniques and dosimetry, complications should decrease. Combined limited surgery and radical radiation therapy should be considered in those patients where a radical mastectomy is not feasible because of psychological or medical problems. Since this procedure results in a cosmetically acceptable breast, radical radiation in early stage breast cancer seems a reasonable alternative to radical mastectomy.

  15. Quantitative study on guinea pig spermatogenesis shows a relative high percentage of early meiotic prophase stages.

    PubMed

    Rodríguez, Rosana E; Wettstein, Rodolfo M

    2004-05-01

    Meiosis is the special double cellular division characterized by the reduction of chromosome number of the final products and recombination of genetic information present in maternal and paternal homologous chromosomes. Early stages of meiotic prophase, leptotene and zygotene (L/Z), are functionally important since homologous chromosomes recognize, align, and pair during them. They are poorly represented in the seminiferous tubules of mammalian species, and this fact turns studies focused on these stages difficult to perform. As a consequence, the molecular bases of these important events are so far poorly known and understood in higher eukaryotes. The purpose of this work was to provide an advantageous experimental mammalian model (with a reasonable number of cells) for biochemical and molecular analysis of early meiotic prophase stages. Here, we present the results of our quantitative study on testes material of both immature and adult guinea pig specimens (Cavia porcellus). We show that their seminiferous tubules contain a comparatively high percentage of L/Z spermatocytes, as well as a very conspicuous chromosome bouquet at the L/Z transition, which points out this species as a well-suited one to address studies on such stages in mammals.

  16. Development sites, feeding modes and early stages of seven European Palloptera species (Diptera, Pallopteridae).

    PubMed

    Rotheray, Graham E

    2014-12-19

    Two hundred and ninety-eight rearing records and 87 larvae and puparia were obtained of seven species of Palloptera Fallén (Diptera, Pallopteridae), mainly in Scotland during 2012-2013. The third stage larva and puparium of each species were assessed morphologically and development sites and feeding modes investigated by rearing, observation and feeding tests. Early stages appear to be distinguished by the swollen, apico-lateral margins of the prothorax which are coated in vestiture and a poorly developed anal lobe with few spicules. Individual pallopteran species are separated by features of the head skeleton, locomotory spicules and the posterior respiratory organs. Five species can be distinguished by unique character states. Observations and feeding tests suggest that the frequently cited attribute of zoophagy is accidental and that saprophagy is the primary larval feeding mode with autumn/winter as the main period of development. Food plants were confirmed for flowerhead and stem developing species and rain is important for maintaining biofilms on which larvae feed. Due to difficulties in capturing adults, especially males, the distribution and abundance of many pallopteran species is probably underestimated. Better informed estimates are possible if early stages are included in biodiversity assessments. To facilitate this for the species investigated, a key to the third stage larva and puparium along with details on finding them, is provided. 

  17. Elevated risk of early reoperation in total hip replacement during the stage of unit closure

    PubMed Central

    Peltola, Mikko; Malmivaara, Antti; Paavola, Mika; Seitsalo, Seppo

    2016-01-01

    Background and purpose — The effects of launch or closure of an entire arthroplasty unit on the first or last patients treated in these units have not been studied. Using a 3-year follow-up, we investigated whether patients who were treated at the launch or closure stage of an arthroplasty unit of a hospital would have a higher risk of reoperation than patients treated in-between at the same units. Patients and methods — From the Finnish Arthroplasty Register, we identified all the units that had performed total joint arthroplasty and the units that were launched or closed in Finland between 1998 and 2011. The risks of reoperation within 3 years for the 41,748 total hip and knee replacements performed due to osteoarthritis in these units were modeled with Cox proportional-hazards regression, separately for hip and knee and for the launch and the closure stage. Results — The unadjusted and adjusted hazard ratios (HRs) for total hip and knee replacements performed in the initial stage of activity of the units that were launched were similar to the reoperation risks in patients who were operated in these units after the early stage of activity. The unadjusted and risk-adjusted HRs for early reoperation after total hip replacement (THR) were increased at the closure stage (adjusted HR = 1.8, 95% CI: 1.2–2.8). The reoperation risk at the closure stage after total knee replacement (TKR) was not increased. Interpretation — The results indicate that closure of units performing total hip replacements poses an increased risk of reoperation. Closures need to be managed carefully to prevent the quality from deteriorating when performing the final arthroplasties. PMID:26541178

  18. Abnormalities of plantar pressure distribution in early, intermediate, and late stages of diabetic neuropathy.

    PubMed

    Sacco, Isabel C N; Hamamoto, Adriana N; Tonicelli, Lucas M G; Watari, Ricky; Ortega, Neli R S; Sartor, Cristina D

    2014-09-01

    Inconsistent findings with regard to plantar pressure while walking in the diabetic population may be due to the heterogeneity of the studied groups resulting from the classification/grouping criteria adopted. The clinical diagnosis and classification of diabetes have inherent uncertainties that compromise the definition of its onset and the differentiation of its severity stages. A fuzzy system could improve the precision of the diagnosis and classification of diabetic neuropathy because it takes those uncertainties into account and combines different assessment methods. Here, we investigated how plantar pressure abnormalities evolve throughout different severity stages of diabetic polyneuropathy (absent, n=38; mild, n=20; moderate, n=47; severe, n=24). Pressure distribution was analysed over five areas while patients walked barefoot. Patients with mild neuropathy displayed an increase in pressure-time integral at the forefoot and a lower peak pressure at the heel. The peak and pressure-time integral under the forefoot and heel were aggravated in later stages of the disease (moderate and severe) compared with early stages of the disease (absent and mild). In the severe group, lower pressures at the lateral forefoot and hallux were observed, which could be related to symptoms that develop with the aggravation of neuropathy: atrophy of the intrinsic foot muscles, reduction of distal muscle activity, and joint stiffness. Although there were clear alterations over the forefoot and in a number of plantar areas with higher pressures within each severity stage, they did not follow the aggravation evolution of neuropathy classified by the fuzzy model. Based on these results, therapeutic interventions should begin in the early stages of this disease to prevent further consequences of the disease.

  19. Temperature Influences Selective Mortality during the Early Life Stages of a Coral Reef Fish

    PubMed Central

    Rankin, Tauna L.; Sponaugle, Su

    2011-01-01

    For organisms with complex life cycles, processes occurring at the interface between life stages can disproportionately impact survival and population dynamics. Temperature is an important factor influencing growth in poikilotherms, and growth-related processes are frequently correlated with survival. We examined the influence of water temperature on growth-related early life history traits (ELHTs) and differential mortality during the transition from larval to early juvenile stage in sixteen monthly cohorts of bicolor damselfish Stegastes partitus, sampled on reefs of the upper Florida Keys, USA over 6 years. Otolith analysis of settlers and juveniles coupled with environmental data revealed that mean near-reef water temperature explained a significant proportion of variation in pelagic larval duration (PLD), early larval growth, size-at-settlement, and growth during early juvenile life. Among all cohorts, surviving juveniles were consistently larger at settlement, but grew more slowly during the first 6 d post-settlement. For the other ELHTs, selective mortality varied seasonally: during winter and spring months, survivors exhibited faster larval growth and shorter PLDs, whereas during warmer summer months, selection on PLD reversed and selection on larval growth became non-linear. Our results demonstrate that temperature not only shapes growth-related traits, but can also influence the direction and intensity of selective mortality. PMID:21559305

  20. Cognitive deterioration in Alzheimer's disease: is the early course predictive of the later stages?

    PubMed

    Capitani, E; Cazzaniga, R; Francescani, A; Spinnler, H

    2004-10-01

    This study investigated the predictive value of the early progression rate of Alzheimer's disease on that of the later stages. We retrospectively evaluated 91 patients affected by possible Alzheimer's disease; the patients had been examined twice with the Milan overall dementia assessment (MODA) scale at an interval of 12 months (53 patients) or 24 months (38 patients). At the first assessment, speed of progression was calculated for each patient dividing the MODA difference from the normality threshold by the time elapsed from the cognitive decline onset. The second assessment of speed of progression was calculated dividing the difference between the two MODA scores by the time elapsed from the first examination. Patients with a slow progression rate in the early stage were unlikely to show a subsequent fast progression rate, and vice versa for patients with a fast early progression. A tool is provided for predicting the speed of cognitive decline of patients from a single MODA assessment. We suggest that, in future clinical trials on Alzheimer's disease, a stratification of participants based on the early rate of cognitive deterioration may be considered.

  1. Early-Stage White Matter Lesions Detected by Multispectral MRI Segmentation Predict Progressive Cognitive Decline

    PubMed Central

    Jokinen, Hanna; Gonçalves, Nicolau; Vigário, Ricardo; Lipsanen, Jari; Fazekas, Franz; Schmidt, Reinhold; Barkhof, Frederik; Madureira, Sofia; Verdelho, Ana; Inzitari, Domenico; Pantoni, Leonardo; Erkinjuntti, Timo

    2015-01-01

    White matter lesions (WML) are the main brain imaging surrogate of cerebral small-vessel disease. A new MRI tissue segmentation method, based on a discriminative clustering approach without explicit model-based added prior, detects partial WML volumes, likely representing very early-stage changes in normal-appearing brain tissue. This study investigated how the different stages of WML, from a “pre-visible” stage to fully developed lesions, predict future cognitive decline. MRI scans of 78 subjects, aged 65–84 years, from the Leukoaraiosis and Disability (LADIS) study were analyzed using a self-supervised multispectral segmentation algorithm to identify tissue types and partial WML volumes. Each lesion voxel was classified as having a small (33%), intermediate (66%), or high (100%) proportion of lesion tissue. The subjects were evaluated with detailed clinical and neuropsychological assessments at baseline and at three annual follow-up visits. We found that voxels with small partial WML predicted lower executive function compound scores at baseline, and steeper decline of executive scores in follow-up, independently of the demographics and the conventionally estimated hyperintensity volume on fluid-attenuated inversion recovery images. The intermediate and fully developed lesions were related to impairments in multiple cognitive domains including executive functions, processing speed, memory, and global cognitive function. In conclusion, early-stage partial WML, still too faint to be clearly detectable on conventional MRI, already predict executive dysfunction and progressive cognitive decline regardless of the conventionally evaluated WML load. These findings advance early recognition of small vessel disease and incipient vascular cognitive impairment. PMID:26696814

  2. Central Pain Processing in Early-Stage Parkinson's Disease: A Laser Pain fMRI Study

    PubMed Central

    Petschow, Christine; Scheef, Lukas; Paus, Sebastian; Zimmermann, Nadine; Schild, Hans H.; Klockgether, Thomas; Boecker, Henning

    2016-01-01

    Background & Objective Pain is a common non-motor symptom in Parkinson’s disease. As dopaminergic dysfunction is suggested to affect intrinsic nociceptive processing, this study was designed to characterize laser-induced pain processing in early-stage Parkinson’s disease patients in the dopaminergic OFF state, using a multimodal experimental approach at behavioral, autonomic, imaging levels. Methods 13 right-handed early-stage Parkinson’s disease patients without cognitive or sensory impairment were investigated OFF medication, along with 13 age-matched healthy control subjects. Measurements included warmth perception thresholds, heat pain thresholds, and central pain processing with event-related functional magnetic resonance imaging (erfMRI) during laser-induced pain stimulation at lower (E = 440 mJ) and higher (E = 640 mJ) target energies. Additionally, electrodermal activity was characterized during delivery of 60 randomized pain stimuli ranging from 440 mJ to 640 mJ, along with evaluation of subjective pain ratings on a visual analogue scale. Results No significant differences in warmth perception thresholds, heat pain thresholds, electrodermal activity and subjective pain ratings were found between Parkinson’s disease patients and controls, and erfMRI revealed a generally comparable activation pattern induced by laser-pain stimuli in brain areas belonging to the central pain matrix. However, relatively reduced deactivation was found in Parkinson’s disease patients in posterior regions of the default mode network, notably the precuneus and the posterior cingulate cortex. Conclusion Our data during pain processing extend previous findings suggesting default mode network dysfunction in Parkinson’s disease. On the other hand, they argue against a genuine pain-specific processing abnormality in early-stage Parkinson’s disease. Future studies are now required using similar multimodal experimental designs to examine pain processing in more advanced

  3. Open lung biopsy in early-stage acute respiratory distress syndrome

    PubMed Central

    Kao, Kuo-Chin; Tsai, Ying-Huang; Wu, Yao-Kuang; Chen, Ning-Hung; Hsieh, Meng-Jer; Huang, Shiu-Feng; Huang, Chung-Chi

    2006-01-01

    Introduction Acute respiratory distress syndrome (ARDS) has heterogeneous etiologies, rapid progressive change and a high mortality rate. To improve the outcome of ARDS, accurate diagnosis is essential to the application of effective early treatment. The present study investigated the clinical effects and safety of open lung biopsy (OLB) in patients with early-stage ARDS of suspected non-infectious origin. Methods We undertook a retrospective study of 41 patients with early-stage ARDS (defined as one week or less after intubation) who underwent OLB in two medical intensive care units of a tertiary care hospital from 1999 to 2005. Data analyzed included baseline characteristics, complication rate, pathological diagnoses, treatment alterations, and hospital survival. Results The age of patients was 55 ± 17 years (mean ± SD). The average ratio of arterial partial pressure of oxygen (PaO2) to fraction of inspired oxygen (FiO2) was 116 ± 43 mmHg (mean ± SD) at biopsy. Seventeen patients (41%) were immunocompromised. Postoperative complications occurred in 20% of patients (8/41). All biopsies provided a pathological diagnosis with a diagnostic yield of 100%. Specific pathological diagnoses were made for 44% of patients (18/41). Biopsy findings led to an alteration of treatment modality in 73% of patients (30/41). The treatment alteration rate was higher in patients with nonspecific diagnoses than in patients with specific diagnoses (p = 0.0024). Overall mortality was 50% (21/41) and was not influenced by age, gender, pre-OLB oxygenation, complication rate, pathological results, and alteration of treatment. There was no surgery-related mortality. The survival rate for immunocompromised patients was better than that for immunocompetent patients (71% versus 33%; p = 0.0187) in this study. Conclusion Our retrospective study suggests that OLB was a useful and acceptably safe diagnostic procedure in some selected patients with early-stage ARDS. PMID:16859510

  4. Subthalamic Nucleus Deep Brain Stimulation in Early Stage Parkinson’s Disease

    PubMed Central

    Charles, David; Konrad, Peter E.; Neimat, Joseph S.; Molinari, Anna L.; Tramontana, Michael G.; Finder, Stuart G.; Gill, Chandler E.; Bliton, Mark J.; Kao, Chris C.; Phibbs, Fenna T.; Hedera, Peter; Salomon, Ronald M.; Cannard, Kevin R.; Wang, Lily; Song, Yanna; Davis, Thomas L.

    2014-01-01

    Background Deep brain stimulation (DBS) is an effective and approved therapy for advanced Parkinson’s disease (PD), and a recent study suggests efficacy in mid-stage disease. This manuscript reports the results of a pilot trial investigating preliminary safety and tolerability of DBS in early PD. Methods Thirty subjects with idiopathic PD (Hoehn & Yahr Stage II off medication), age 50–75, on medication ≥ 6 months but < 4 years, and without motor fluctuations or dyskinesias were randomized to optimal drug therapy (ODT) (n=15) or DBS+ODT (n=15). Co-primary endpoints were the time to reach a 4-point worsening from baseline in the UPDRS-III off therapy and the change in levodopa equivalent daily dose from baseline to 24 months. Results As hypothesized, the mean UPDRS total and part III scores were not significantly different on or off therapy at 24 months. The DBS+ODT group took less medication at all time points, and this reached maximum difference at 18 months. With a few exceptions, differences in neuropsychological functioning were not significant. Two subjects in the DBS+ODT group suffered serious adverse events; remaining adverse events were mild or transient. Conclusions This study demonstrates that subjects with early stage PD will enroll in and complete trials testing invasive therapies and provides preliminary evidence that DBS is well tolerated in early PD. The results of this trial provide the data necessary to design a large, phase III, double-blind, multicenter trial investigating the safety and efficacy of DBS in early PD. PMID:24768120

  5. Different soil respiration responses to litter manipulation in three subtropical successional forests.

    PubMed

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-12-11

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests.

  6. Different soil respiration responses to litter manipulation in three subtropical successional forests

    NASA Astrophysics Data System (ADS)

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-12-01

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests.

  7. Different soil respiration responses to litter manipulation in three subtropical successional forests

    PubMed Central

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-01-01

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests. PMID:26656136

  8. Lexical Access in Early Stages of Visual Word Processing: A Single-Trial Correlational MEG Study of Heteronym Recognition

    ERIC Educational Resources Information Center

    Solomyak, Olla; Marantz, Alec

    2009-01-01

    We present an MEG study of heteronym recognition, aiming to distinguish between two theories of lexical access: the "early access" theory, which entails that lexical access occurs at early (pre 200 ms) stages of processing, and the "late access" theory, which interprets this early activity as orthographic word-form identification rather than…

  9. Spatial variations in mortality in pelagic early life stages of a marine fish (Gadus morhua)

    NASA Astrophysics Data System (ADS)

    Langangen, Øystein; Stige, Leif C.; Yaragina, Natalia A.; Ottersen, Geir; Vikebø, Frode B.; Stenseth, Nils Chr.

    2014-09-01

    Mortality of pelagic eggs and larvae of marine fish is often assumed to be constant both in space and time due to lacking information. This may, however, be a gross oversimplification, as early life stages are likely to experience large variations in mortality both in time and space. In this paper we develop a method for estimating the spatial variability in mortality of eggs and larvae. The method relies on survey data and physical-biological particle-drift models to predict the drift of ichthyoplankton. Furthermore, the method was used to estimate the spatially resolved mortality field in the egg and larval stages of Barents Sea cod (Gadus morhua). We analyzed data from the Barents Sea for the period between 1959 and 1993 when there are two surveys available: a spring and a summer survey. An individual-based physical-biological particle-drift model, tailored to the egg and larval stages of Barents Sea cod, was used to predict the drift trajectories from the observed stage-specific distributions in spring to the time of observation in the summer, a drift time of approximately 45 days. We interpreted the spatial patterns in the differences between the predicted and observed abundance distributions in summer as reflecting the spatial patterns in mortality over the drift period. Using the estimated mortality fields, we show that the spatial variations in mortality might have a significant impact on survival to later life stages and we suggest that there may be trade-offs between increased early survival in off shore regions and reduced probability of ending up in the favorable nursing grounds in the Barents Sea. In addition, we show that accounting for the estimated mortality field, improves the correlation between a simulated recruitment index and observation-based indices of juvenile abundance.

  10. Plasma Epidermal Growth Factor Decreased in the Early Stage of Parkinson’s Disease

    PubMed Central

    Jiang, Qian-Wen; Wang, Cheng; Zhou, Yi; Hou, Miao-Miao; Wang, Xi; Tang, Hui-Dong; Wu, Yi-Wen; Ma, Jian-Fang; Chen, Sheng-Di

    2015-01-01

    Epidermal growth factor (EGF) is a neurotrophic factor that plays an important role in Parkinson’s disease (PD). We measured plasma EGF level in PD, essential tremor (ET) and normal controls to investigate whether it changes in PD and whether it is associated with motor and non-motor symptoms of PD. 100 patients with PD, 40 patients with ET as disease control and 76 healthy persons were enrolled in the present study. Motor and non-motor symptoms were assessed by different scales. Plasma EGF levels of three groups were measured by enzyme-linked immunosorbent assay kit. Spearman test and linear logistics regression model were used to test the correlation of EGF with motor and non-motor symptoms of PD. Plasma EGF level was significantly decreased in early PD patients compared with normal control, but not in advanced PD patients. Interestingly, plasma EGF level was significantly increased in advanced PD and total PD patients compared with ET patients, but not in early PD patients. In addition, plasma EGF level was correlated with UPDRS-III scores in PD. Also plasma EGF level was correlated with UPDRS-III scores and NMS scores in early PD. Our results suggested that plasma EGF decreased in the early stage of PD and increased later on in the PD disease course. Also, plasma EGF level was increased significantly in PD compared with ET patients and correlated with motor and non-motor symptoms in early PD. PMID:26029474

  11. Subsets of a Large Cognitive Battery Better Power Clinical Trials on Early Stage Alzheimer Disease

    PubMed Central

    Xiong, Chengjie; Weng, Hua; Bennett, David A.; Boyle, Patricia A.; Shah, Raj C.; Fague, Scot; Hall, Charles B.; Lipton, Richard B.; Morris, John C.

    2014-01-01

    Background/Aims Cognitive batteries routinely used by the Alzheimer disease (AD) research community may contain items uninformative for tracking disease progression to power clinical trials on early stage AD. We aim to identify subsets of the most informative items from an existing cognitive battery for better powering clinical trials on early AD. Methods Longitudinal change in item scores from the battery was associated with the onset of Mild Cognitive Impairment (MCI) in 1513 elderly individuals. Items whose longitudinal changes were correlated with the onset of MCI were selected as informative for tracking the early cognitive progression. Results 226 items in the battery were annually assessed over a follow-up of up to 13 years. Changes of item scores over time from 187 items were significantly correlated with the onset of MCI. For clinical trials on preclinical AD and on MCI, informative items permit smaller or similar sample sizes as compared to the entire battery, whereas uninformative items require much larger sample sizes. Conclusions Longitudinal changes in item scores from about 17% of items in the cognitive battery are uninformative for tracking early disease progression. Clinical trials on early AD can be better powered using informative items rather than the entire battery. PMID:25376544

  12. HIV-1 Nef sequesters MHC-I intracellularly by targeting early stages of endocytosis and recycling

    PubMed Central

    Dirk, Brennan S.; Pawlak, Emily N.; Johnson, Aaron L.; Van Nynatten, Logan R.; Jacob, Rajesh A.; Heit, Bryan; Dikeakos, Jimmy D.

    2016-01-01

    A defining characteristic of HIV-1 infection is the ability of the virus to persist within the host. Specifically, MHC-I downregulation by the HIV-1 accessory protein Nef is of critical importance in preventing infected cells from cytotoxic T-cell mediated killing. Nef downregulates MHC-I by modulating the host membrane trafficking machinery, resulting in the endocytosis and eventual sequestration of MHC-I within the cell. In the current report, we utilized the intracellular protein-protein interaction reporter system, bimolecular fluorescence complementation (BiFC), in combination with super-resolution microscopy, to track the Nef/MHC-I interaction and determine its subcellular localization in cells. We demonstrate that this interaction occurs upon Nef binding the MHC-I cytoplasmic tail early during endocytosis in a Rab5-positive endosome. Disruption of early endosome regulation inhibited Nef-dependent MHC-I downregulation, demonstrating that Nef hijacks the early endosome to sequester MHC-I within the cell. Furthermore, super-resolution imaging identified that the Nef:MHC-I BiFC complex transits through both early and late endosomes before ultimately residing at the trans-Golgi network. Together we demonstrate the importance of the early stages of the endocytic network in the removal of MHC-I from the cell surface and its re-localization within the cell, which allows HIV-1 to optimally evade host immune responses. PMID:27841315

  13. Large spinose microfossils in Ediacaran rocks as resting stages of early animals.

    PubMed

    Cohen, Phoebe A; Knoll, Andrew H; Kodner, Robin B

    2009-04-21

    Large (>100 microm), profusely ornamented microfossils comprise a distinctive paleontological component of sedimentary rocks deposited during the Ediacaran Period (635-542 million years ago). Smaller spinose fossils in Paleozoic rocks have commonly been interpreted as algal cysts or phycomata, but the Ediacaran populations differ from modern algal analogs in size, shape, ultrastructure, and internal contents. In contrast, cysts formed during the diapause egg-resting stages of many metazoans share features of size, ornamentation, and internal contents with large ornamented Ediacaran microfossils (LOEMs). Moreover, transmission electron microscopic observations of animal-resting cysts reveal a 3-layer wall ultrastructure comparable to that of LOEM taxa. Interpretation of these distinctive Ediacaran microfossils as resting stages in early metazoan life cycles offers additional perspectives on their functional morphology and stratigraphic distribution. Based on comparisons with modern marine invertebrates, the recalcitrant life stage represented by LOEMs is interpreted as an evolutionary response to prolonged episodes of bottom water anoxia in Ediacaran shelf and platform environments. As predicted by this hypothesis, the later Ediacaran disappearance of LOEM taxa coincides with geochemical evidence for a marked decline in the extent of oxygen-depleted waters impinging on continental shelves and platforms. Thus, the form, diversity, and stratigraphic range of LOEMs illuminate life cycle evolution in early animals as influenced by the evolving redox state of the oceans.

  14. Involved Node Radiation Therapy: An Effective Alternative in Early-Stage Hodgkin Lymphoma

    SciTech Connect

    Maraldo, Maja V.; Aznar, Marianne C.; Vogelius, Ivan R.; Petersen, Peter M.; Specht, Lena

    2013-03-15

    Purpose: The involved node radiation therapy (INRT) strategy was introduced for patients with Hodgkin lymphoma (HL) to reduce the risk of late effects. With INRT, only the originally involved lymph nodes are irradiated. We present treatment outcome in a retrospective analysis using this strategy in a cohort of 97 clinical stage I-II HL patients. Methods and Materials: Patients were staged with positron emission tomography/computed tomography scans, treated with adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy, and given INRT (prechemotherapy involved nodes to 30 Gy, residual masses to 36 Gy). Patients attended regular follow-up visits until 5 years after therapy. Results: The 4-year freedom from disease progression was 96.4% (95% confidence interval: 92.4%-100.4%), median follow-up of 50 months (range: 4-71 months). Three relapses occurred: 2 within the previous radiation field, and 1 in a previously uninvolved region. The 4-year overall survival was 94% (95% confidence interval: 88.8%-99.1%), median follow-up of 58 months (range: 4-91 months). Early radiation therapy toxicity was limited to grade 1 (23.4%) and grade 2 (13.8%). During follow-up, 8 patients died, none from HL, 7 malignancies were diagnosed, and 5 patients developed heart disease. Conclusions: INRT offers excellent tumor control and represents an effective alternative to more extended radiation therapy in the combined modality treatment for early-stage HL.

  15. Challenges and developments in research of the early stages of bipolar disorder.

    PubMed

    Brietzke, Elisa; Rosa, Adriane R; Pedrini, Mariana; Noto, Mariane N; Kapczinski, Flavio; Scott, Jan

    2016-01-01

    Recently, attention in the field of bipolar disorder (BD) has focused on prevention, including early detection and intervention, as these strategies have the potential to delay, lessen the severity, or even prevent full-blown episodes of BD. Although knowledge of the neurobiology of BD has advanced substantially in the last two decades, most research was conducted with chronic patients. The objective of this paper is to comprehensively review the literature regarding the early stages of BD, to explore recent discoveries on the neurobiology of these stages, and to discuss implications for research and clinical care. The following databases were searched: PubMed, PsycINFO, Cochrane Library, and SciELO. Articles published in English from inception to December 2015 were retrieved. Several research approaches were used, including examination of offspring studies, retrospective studies, prospective studies of clinical high-risk populations, and exploration of the progression after the first manic episode. Investigations with neuroimaging, cognition assessments, and biomarkers provide promising (although not definitive) evidence of alterations in the neural substrate during the at-risk stage. Research on BD should be expanded to encompass at-risk states and aligned with recent methodological progress in neuroscience.

  16. Early-stage primary signet ring cell carcinoma of the colon

    PubMed Central

    Kim, Jae Hyun; Park, Seun Ja; Park, Moo In; Moon, Won; Kim, Sung Eun

    2013-01-01

    Primary signet ring cell carcinoma of the colorectum detected at an early stage is very rare; most cases are detected at an advanced stage. Therefore, its prognosis is poorer than that of ordinary colorectal cancer. A 56-year-old Korean man was seen at this hospital for management of signet ring cell carcinoma of the colon. Colonoscopic examination revealed a IIa-like, ill-defined and flatly elevated 9-mm residual tumor in the cecum. Endoscopic mucosal resection was preformed. Pathological examination of the resected specimen revealed signet ring cell carcinoma that had invaded the lamina propria without venous or perineural invasion. Abdominal computed tomography (CT) and positron CT showed no evidence of primary lesions or distant metastasis. An additional laparoscopic right-hemicolectomy was performed; no residual tumor or lymph node metastasis was found. We report a case of primary signet ring cell carcinoma of the colon detected at an early stage and provide a review of the literature. PMID:23840131

  17. Changes of statistical structural fluctuations unveils an early compacted degraded stage of PNS myelin

    NASA Astrophysics Data System (ADS)

    Poccia, Nicola; Campi, Gaetano; Ricci, Alessandro; Caporale, Alessandra S.; di Cola, Emanuela; Hawkins, Thomas A.; Bianconi, Antonio

    2014-06-01

    Degradation of the myelin sheath is a common pathology underlying demyelinating neurological diseases from Multiple Sclerosis to Leukodistrophies. Although large malformations of myelin ultrastructure in the advanced stages of Wallerian degradation is known, its subtle structural variations at early stages of demyelination remains poorly characterized. This is partly due to the lack of suitable and non-invasive experimental probes possessing sufficient resolution to detect the degradation. Here we report the feasibility of the application of an innovative non-invasive local structure experimental approach for imaging the changes of statistical structural fluctuations in the first stage of myelin degeneration. Scanning micro X-ray diffraction, using advances in synchrotron x-ray beam focusing, fast data collection, paired with spatial statistical analysis, has been used to unveil temporal changes in the myelin structure of dissected nerves following extraction of the Xenopus laevis sciatic nerve. The early myelin degeneration is a specific ordered compacted phase preceding the swollen myelin phase of Wallerian degradation. Our demonstration of the feasibility of the statistical analysis of SµXRD measurements using biological tissue paves the way for further structural investigations of degradation and death of neurons and other cells and tissues in diverse pathological states where nanoscale structural changes may be uncovered.

  18. Pesticides in urban streams and early life stages of Pacific coho salmon.

    PubMed

    King, Kerensa A; Grue, Christian E; Grassley, James M; Fisk, Robert J

    2013-04-01

    Pesticides are frequently detected in urban streams and are believed to be primarily the result of homeowner use. Although concentrations in most cases are low (<1 µg/L), there is concern that pesticide inputs threaten efforts to restore and enhance salmon habitat. The authors exposed early life stages of coho salmon (Oncorhynchus kisutch) to a pesticide mixture ("cocktail") representative of those pesticides most frequently reported in urban streams in western Washington State, USA. Life stages were continuously exposed to pulses of the cocktail simulating those in urban streams in fall and winter when coho salmon eggs and sac fry are present. Nominal concentrations of eight herbicides, two insecticides, a fungicide, and a breakdown product were the maximum detected. Fertilization, hatching success, survival, deformities, and growth of fry were not significantly affected. A reduction in fertilization success (19-25%) was not reproducible even when gametes were exposed to 100 times the maximum concentrations detected. Based on the end points examined in the present study, the results suggest that direct exposure to the pesticides most frequently detected in urban streams in western Washington does not impair early life stages of coho salmon and is not a major factor governing the recovery of salmon populations. The extent to which pesticide exposure would affect smoltification, outmigration, and ocean survival needs to be determined.

  19. Genome-scale transcriptomic insights into early-stage fruit development in woodland strawberry Fragaria vesca.

    PubMed

    Kang, Chunying; Darwish, Omar; Geretz, Aviva; Shahan, Rachel; Alkharouf, Nadim; Liu, Zhongchi

    2013-06-01

    Fragaria vesca, a diploid woodland strawberry with a small and sequenced genome, is an excellent model for studying fruit development. The strawberry fruit is unique in that the edible flesh is actually enlarged receptacle tissue. The true fruit are the numerous dry achenes dotting the receptacle's surface. Auxin produced from the achene is essential for the receptacle fruit set, a paradigm for studying crosstalk between hormone signaling and development. To investigate the molecular mechanism underlying strawberry fruit set, next-generation sequencing was employed to profile early-stage fruit development with five fruit tissue types and five developmental stages from floral anthesis to enlarged fruits. This two-dimensional data set provides a systems-level view of molecular events with precise spatial and temporal resolution. The data suggest that the endosperm and seed coat may play a more prominent role than the embryo in auxin and gibberellin biosynthesis for fruit set. A model is proposed to illustrate how hormonal signals produced in the endosperm and seed coat coordinate seed, ovary wall, and receptacle fruit development. The comprehensive fruit transcriptome data set provides a wealth of genomic resources for the strawberry and Rosaceae communities as well as unprecedented molecular insight into fruit set and early stage fruit development.

  20. Relationship between early and late stages of information processing: an event-related potential study

    PubMed Central

    Portella, Claudio; Machado, Sergio; Arias-Carrión, Oscar; Sack, Alexander T.; Silva, Julio Guilherme; Orsini, Marco; Leite, Marco Antonio Araujo; Silva, Adriana Cardoso; Nardi, Antonio E.; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro

    2012-01-01

    The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2), N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) and the reaction time (RT). In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) was found. Therefore, we propose that if the secondary processing of visual input (P200 latency) occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency), motor response processing (PMP latency), reorganization of attention and working memory update (P300 latency), and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude). PMID:23355929

  1. Large spinose microfossils in Ediacaran rocks as resting stages of early animals

    PubMed Central

    Cohen, Phoebe A.; Knoll, Andrew H.; Kodner, Robin B.

    2009-01-01

    Large (>100 μm), profusely ornamented microfossils comprise a distinctive paleontological component of sedimentary rocks deposited during the Ediacaran Period (635–542 million years ago). Smaller spinose fossils in Paleozoic rocks have commonly been interpreted as algal cysts or phycomata, but the Ediacaran populations differ from modern algal analogs in size, shape, ultrastructure, and internal contents. In contrast, cysts formed during the diapause egg-resting stages of many metazoans share features of size, ornamentation, and internal contents with large ornamented Ediacaran microfossils (LOEMs). Moreover, transmission electron microscopic observations of animal-resting cysts reveal a 3-layer wall ultrastructure comparable to that of LOEM taxa. Interpretation of these distinctive Ediacaran microfossils as resting stages in early metazoan life cycles offers additional perspectives on their functional morphology and stratigraphic distribution. Based on comparisons with modern marine invertebrates, the recalcitrant life stage represented by LOEMs is interpreted as an evolutionary response to prolonged episodes of bottom water anoxia in Ediacaran shelf and platform environments. As predicted by this hypothesis, the later Ediacaran disappearance of LOEM taxa coincides with geochemical evidence for a marked decline in the extent of oxygen-depleted waters impinging on continental shelves and platforms. Thus, the form, diversity, and stratigraphic range of LOEMs illuminate life cycle evolution in early animals as influenced by the evolving redox state of the oceans. PMID:19366668

  2. Diversity and dynamics of bacterial communities in early life stages of the Caribbean coral Porites astreoides

    PubMed Central

    Sharp, Koty H; Distel, Dan; Paul, Valerie J

    2012-01-01

    In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis on the TRFLP results do not support significant variation in the bacterial communities associated with P. astreoides larvae across collection location, collection year or developmental stage. The results are the first evidence of vertical transmission (from parent to offspring) of bacteria in corals. The results also show that at least two groups of bacterial taxa, the RCA bacteria and Marinobacter, are consistently associated with juvenile P. astreoides against a complex background of microbial associations, indicating that some components of the microbial community are long-term associates of the corals and may impact host health and survival. PMID:22113375

  3. Dynamics of laser ablation at the early stage during and after ultrashort pulse

    NASA Astrophysics Data System (ADS)

    Ilnitsky, D. K.; Khokhlov, V. A.; Zhakhovsky, V. V.; Petrov, Yu V.; Migdal, K. P.; Inogamov, N. A.

    2016-11-01

    Study of material flow in two-temperature states is needed for a fundamental understanding the physics of femtosecond laser ablation. To explore phenomena at a very early stage of laser action on a metallic target our in-house two-temperature hydrodynamics code is used here. The early stage covers duration of laser pulse with next first few picoseconds. We draw attention to the difference in behavior at this stage between the cases: (i) of an ultrathin film (thickness of order of skin depth d skin or less), (ii) thin films (thickness of a film is 4-7 of d skin for gold), and (iii) bulk targets (more than 10d skin for gold). We demonstrate that these differences follow from a competition among conductive cooling of laser excited electrons in a skin layer, electron-ion coupling, and hydrodynamics of unloading caused by excess of pressure of excited free electrons. Conductive cooling of the skin needs a heat sink, which is performed by the cold material outside the skin. Such sink is unavailable in the ultrathin films.

  4. Developing an inventor support service which performs early stage market and manufacturing evaluations. [Final Report

    SciTech Connect

    Not Available

    1991-10-01

    American businesses are learning the difficult high cost lesson of ignoring production and market factors (producibility, unit product cost (UPC), marketability, etc) during the engineering design phase of product development. Studies have shown that the Japanese spend three times as long as Americans in the design feasibility and decision process of new product introductions and one third the amount of time in the implementation of those products. There is a 20 to 1 cost benefit on effort applied in the design phase versus the production phase of the product life cycle. The number one goal of this project was to establish an organization that has, as one of its purposes, the providing of services responsive to the needs of independent inventors. The number two goal was to demonstrate the value of providing marketing and manufacturing counsel at an early stage in the product development process. The first study goal was met by providing the materials and information necessary to establish an evaluation team and an organization to handle such evaluations. The second study goal was met by demonstrating the impact of early market analysis and manufacturing considerations on product design and therefore on the description of the invention for four different inventions. These inventions were selected at various stages of development. Regardless of stage of development, the marketing and manufacturing reviews resulted in significant changes in design and/or market positioning.

  5. Developing an inventor support service which performs early stage market and manufacturing evaluations. Final report

    SciTech Connect

    Not Available

    1991-10-01

    American businesses are learning the difficult high cost lesson of ignoring production and market factors (producibility, unit product cost (UPC), marketability, etc) during the engineering design phase of product development. Studies have shown that the Japanese spend three times as long as Americans in the design feasibility and decision process of new product introductions and one third the amount of time in the implementation of those products. There is a 20 to 1 cost benefit on effort applied in the design phase versus the production phase of the product life cycle. The number one goal of this project was to establish an organization that has, as one of its purposes, the providing of services responsive to the needs of independent inventors. The number two goal was to demonstrate the value of providing marketing and manufacturing counsel at an early stage in the product development process. The first study goal was met by providing the materials and information necessary to establish an evaluation team and an organization to handle such evaluations. The second study goal was met by demonstrating the impact of early market analysis and manufacturing considerations on product design and therefore on the description of the invention for four different inventions. These inventions were selected at various stages of development. Regardless of stage of development, the marketing and manufacturing reviews resulted in significant changes in design and/or market positioning.

  6. Imaging and detection of early stage dental caries with an all-optical photoacoustic microscope

    NASA Astrophysics Data System (ADS)

    Hughes, D. A.; Sampathkumar, A.; Longbottom, C.; Kirk, K. J.

    2015-01-01

    Tooth decay, at its earliest stages, manifests itself as small, white, subsurface lesions in the enamel. Current methods for detection in the dental clinic are visual and tactile investigations, and bite-wing X-ray radiographs. These techniques suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease due to the small size (<100μm) of the lesion. A fine-resolution (600 nm) ultra-broadband (200 MHz) all-optical photoacoustic microscopy system was is used to image the early signs of tooth decay. Ex-vivo tooth samples exhibiting white spot lesions were scanned and were found to generate a larger (one order of magnitude) photoacoustic (PA) signal in the lesion regions compared to healthy enamel. The high contrast in the PA images potentially allows lesions to be imaged and measured at a much earlier stage than current clinical techniques allow. PA images were cross referenced with histology photographs to validate our experimental results. Our PA system provides a noncontact method for early detection of white-spot lesions with a high detection bandwidth that offers advantages over previously demonstrated ultrasound methods. The technique provides the sensing depth of an ultrasound system, but with the spatial resolution of an optical system.

  7. Diversity and dynamics of bacterial communities in early life stages of the Caribbean coral Porites astreoides.

    PubMed

    Sharp, Koty H; Distel, Dan; Paul, Valerie J

    2012-04-01

    In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis on the TRFLP results do not support significant variation in the bacterial communities associated with P. astreoides larvae across collection location, collection year or developmental stage. The results are the first evidence of vertical transmission (from parent to offspring) of bacteria in corals. The results also show that at least two groups of bacterial taxa, the RCA bacteria and Marinobacter, are consistently associated with juvenile P. astreoides against a complex background of microbial associations, indicating that some components of the microbial community are long-term associates of the corals and may impact host health and survival.

  8. Circulating microRNAs, possible indicators of progress of rat hepatocarcinogenesis from early stages.

    PubMed

    Sukata, Tokuo; Sumida, Kayo; Kushida, Masahiko; Ogata, Keiko; Miyata, Kaori; Yabushita, Setsuko; Uwagawa, Satoshi

    2011-01-15

    MicroRNAs (miRNAs), a class of small noncoding RNAs that regulate gene expression at the posttranscriptional level, are believed promising biomarkers for several diseases as well as a novel target of drugs, including cancer. In particular, miRNAs might allow detection of early stages of carcinogenesis. The present study was conducted to provide concrete evidence using chemical-induced hepatocarcinogenesis in rat as a model. We thereby observed aberrant fluctuation of circulating miRNAs in the serum of rats not only with neoplastic lesions such as hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC), but also with preneoplastic lesions, such as foci of hepatocellular alteration (FHA). Additional qRT-PCR analysis revealed gradual elevation of some circulating miRNAs (i.e., let-7a, let-7f, miR-34a, miR-98, miR-331, miR-338 and miR-652) with progress of hepatocarcinogenesis. Interestingly, increased levels of let-7a, let-7f and miR-98 were statistically significant even in the serum of rats at very early stages. These findings provide the first evidences that circulating miRNAs have the potential to predict carcinogenesis at earlier stages, preneoplastic lesions than with previous biomarkers and that they might be utilized to monitor the progress of tumor development.

  9. A comparison of seed banks across a sand dune successional gradient at Lake Michigan dunes (Indiana, USA)

    USGS Publications Warehouse

    Leicht-Young, S. A.; Pavlovic, N.B.; Grundel, R.; Frohnapple, K.J.

    2009-01-01

    In habitats where disturbance is frequent, seed banks are important for the regeneration of vegetation. Sand dune systems are dynamic habitats in which sand movement provides intermittent disturbance. As succession proceeds from bare sand to forest, the disturbance decreases. At Indiana Dunes National Lakeshore, we examined the seed banks of three habitat types across a successional gradient: foredunes, secondary dunes, and oak savanna. There were differences among the types of species that germinated from each of the habitats. The mean seed bank density increased across the successional gradient by habitat, from 376 to 433 to 968 seeds m-2, but with foredune and secondary dune seed bank densities being significantly lower than the savanna seed bank density. The number of seeds germinated was significantly correlated with soil organic carbon, demonstrating for this primary successional sequence that seed density increases with stage and age. The seed bank had much lower species richness than that of the aboveground vegetation across all habitats. Among sites within a habitat type, the similarity of species germinated from the seed banks was very low, illustrating the variability of the seed bank even in similar habitat types. These results suggest that restoration of these habitats cannot rely on seed banks alone. ?? 2008 Springer Science+Business Media B.V.

  10. A mid-term follow-up of Koutsogiannis’ osteotomy in adult-acquired flatfoot stage II and “early stage III”

    PubMed Central

    Arvinius, Camilla; Manrique, Elena; Urda, Antonio; Cardoso, Zulema; Galeote, Jose Enrique; Marco, Fernando

    2017-01-01

    Introduction: Koutsogiannis’ osteotomy has been widely described to treat adult-acquired flatfoot. However, few articles describe its midterm follow-up. Our aim was to study clinical and radiological outcomes at least one year after surgery and to analyze whether a combined procedure on the medial soft tissue affected these outcomes. Methods: We performed a retrospective study of 30 feet of patients who underwent a Koutsogiannis’ osteotomy due to adult-acquired flatfoot stage II and “early stage III”: a stage III acquired flatfoot without any important structural deformities. The parameters studied were additional medial soft tissue procedures, clinical outcome through the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and midfoot score as well as complications and radiological measurements. Results: Sixteen cases were “early stage III” and 14 stage II. Thirteen patients underwent an associated posterior tibial tendon (PTT) revision: in three cases an end-to-end suture was possible, seven cases needed a FDL transposition, and three underwent synovectomy. Statistically significant improvement was found in the AOFAS score although no significant changes were seen radiologically. No additional benefit was found with the revision of the posterior tibial tendon. As to clinical and radiological results, no differences were found between stage II and “early stage III”. Five cases presented a mild dysesthesia but only one patient needed neurolysis. Conclusions: We consider the Koutsogiannis’ osteotomy to be a safe and effective procedure to reduce pain in patients with stage II and “early stage III” adult-acquired flatfoot. PMID:28304274

  11. [Stage 3 recommendations--the early recognition of breast cancer in Germany. Abridged version for medical practitioners].

    PubMed

    Schulz, K-D; Kreienberg, R; Fischer, R; Albert, U-S

    2003-06-01

    The Aim of this level 3 good clinical practice guideline is to help physicians, women and patients in decision making about the appropriate health care for early detection of breast cancer. The principle of early detection of breast cancer comprise the detection and diagnosis of premalignant breast tumors (stage 0, Carcinoma in situ), risk reduction of cancer development as well as the detection and diagnosis of breast cancer at an early stage (stage I), with a 90% chance of cure as shown by a large number of clinical trials. To establish a nation wide, comprehensive quality assuring program for the early detection of breast cancer the guideline summarized in the following paper offers the basis for a timely mortality reduction of breast cancer. The cure of early stage disease will be additionally possible by less invasive treatment allowing patients to maintain quality of life. The guideline leads to a major improvement of women's health care.

  12. Functional magnetic resonance imaging and cognition at the very early stage of MS.

    PubMed

    Audoin, Bertrand; Au Duong, My Van; Malikova, Irina; Confort-Gouny, Sylviane; Ibarrola, Danielle; Cozzone, Patrick J; Pelletier, Jean; Ranjeva, Jean-Philippe

    2006-06-15

    Dysfunction of high controlled information processing is present in patients with multiple sclerosis (MS) right at the beginning of the disease. One hypothesis is that disruption of communication inside large-scale cortical networks, occurring as a consequence of white matter damage, may constitute the anatomical substrate of cognitive impairment at the very early stage of MS. Disturbance of interregional synchronization might be the main pathogenic factor in controlled information processing deficiency in early MS. Preliminary functional MRI studies (fMRI) have provided important clues to corroborate the connectivity hypotheses. First, brain connectivity assessed by fMRI has brought new data about the influence of diffuse white matter damage on connectivity efficiency inside large-scale networks. These studies have suggested that connectivity disturbances occur inside the working memory network in patients at the very early stage of MS and appear related to the extent of structural white matter damage. Also, fMRI studies have suggested that patients may partially compensate for connectivity impairment by a greater cognitive control. Such a compensatory mechanism could limit the determinant functional impact of diffuse white matter damage on high controlled information processing.

  13. Accelerated Partial Breast Irradiation Using Only Intraoperative Electron Radiation Therapy in Early Stage Breast Cancer

    SciTech Connect

    Maluta, Sergio; Dall'Oglio, Stefano; Marciai, Nadia; Gabbani, Milena; Franchini, Zeno; Pietrarota, Paolo; Meliado, Gabriele; Guariglia, Stefania; Cavedon, Carlo

    2012-10-01

    Background: We report the results of a single-institution, phase II trial of accelerated partial breast irradiation (APBI) using a single dose of intraoperative electron radiation therapy (IOERT) in patients with low-risk early stage breast cancer. Methods and Materials: A cohort of 226 patients with low-risk, early stage breast cancer were treated with local excision and axillary management (sentinel node biopsy with or without axillary node dissection). After the surgeon temporarily reapproximated the excision cavity, a dose of 21 Gy using IOERT was delivered to the tumor bed, with a margin of 2 cm laterally. Results: With a mean follow-up of 46 months (range, 28-63 months), only 1 case of local recurrence was reported. The observed toxicity was considered acceptable. Conclusions: APBI using a single dose of IOERT can be delivered safely in women with early, low-risk breast cancer in carefully selected patients. A longer follow-up is needed to ascertain its efficacy compared to that of the current standard treatment of whole-breast irradiation.

  14. Effect of salicylic acid on early life stages of common carp (Cyprinus carpio).

    PubMed

    Zivna, Dana; Sehonova, Pavla; Plhalova, Lucie; Marsalek, Petr; Blahova, Jana; Prokes, Miroslav; Divisova, Lenka; Stancova, Vlasta; Dobsikova, Radka; Tichy, Frantisek; Siroka, Zuzana; Svobodova, Zdenka

    2015-07-01

    Environmental concentrations of pharmaceutical residues are often low; nevertheless, they are designed to have biological effects at low doses. The aim of this study was to assess the effects of salicylic acid on the growth and development of common carp (Cyprinus carpio) early life stages with respect to antioxidant defence enzymes. An embryo-larval toxicity test lasting 34 days was performed according to OECD guidelines 210 (Fish, Early-life Stage Toxicity Test). The tested concentrations were 0.004, 0.04, 0.4, 4 and 20mg/l of salicylic acid. Hatching, early ontogeny, and both morphometric and condition characteristics were significantly influenced by subchronic exposure to salicylic acid. Also, changes in antioxidant enzyme activity and an increase in lipid peroxidation were observed. The LOEC value was found to be 0.004 mg/l salicylic acid. The results of our study confirm the suggestion that subchronic exposure to salicylic acid at environmental concentrations can have significant effects on aquatic vertebrates.

  15. Heterogeneity of Parkinson's disease in the early clinical stages using a data driven approach

    PubMed Central

    Lewis, S; Foltynie, T; Blackwell, A; Robbins, T; Owen, A; Barker, R

    2005-01-01

    Objective: To investigate the heterogeneity of idiopathic Parkinson's disease (PD) in a data driven manner among a cohort of patients in the early clinical stages of the disease meeting established diagnostic criteria. Methods: Data on demographic, motor, mood, and cognitive measures were collected from 120 consecutive patients in the early stages of PD (Hoehn and Yahr I–III) attending a specialist PD research clinic. Statistical cluster analysis of the data allowed the existence of the patient subgroups generated to be explored. Results: The analysis revealed four main subgroups: (a) patients with a younger disease onset; (b) a tremor dominant subgroup of patients; (c) a non-tremor dominant subgroup with significant levels of cognitive impairment and mild depression; and (d) a subgroup with rapid disease progression but no cognitive impairment. Conclusions: This study complements and extends previous research by using a data driven approach to define the clinical heterogeneity of early PD. The approach adopted in this study for the identification of subgroups of patients within Parkinson's disease has important implications for generating testable hypotheses on defining the heterogeneity of this common condition and its aetiopathological basis and thus its treatment. PMID:15716523

  16. An informational diversity framework, illustrated with sexually deceptive orchids in early stages of speciation.

    PubMed

    Smouse, Peter E; Whitehead, Michael R; Peakall, Rod

    2015-11-01

    Reconstructing evolutionary history for emerging species complexes is notoriously difficult, with newly isolated taxa often morphologically cryptic and the signature of reproductive isolation often restricted to a few genes. Evidence from multiple loci and genomes is highly desirable, but multiple inputs require 'common currency' translation. Here we deploy a Shannon information framework, converting into diversity analogue, which provides a common currency analysis for maternally inherited haploid and bi-parentally inherited diploid nuclear markers, and then extend that analysis to construction of minimum-spanning networks for both genomes. The new approach is illustrated with a quartet of cryptic congeners from the sexually deceptive Australian orchid genus Chiloglottis, still in the early stages of speciation. Divergence is more rapid for haploid plastids than for nuclear markers, consistent with the effective population size differential (N(ep) < (N(en)), but divergence patterns are broadly correlated for the two genomes. There are nevertheless intriguing discrepancies between the emerging plastid and nuclear signals of early phylogenetic radiation of these taxa, and neither pattern is entirely consistent with the available information on the sexual cues used by the orchids to lure the pollinators enforcing reproductive isolation. We describe possible extensions of this methodology to multiple ploidy levels and other types of markers, which should increase the range of application to any taxonomic assemblage in the very early stages of reproductive isolation and speciation.

  17. Membrane bound IL-15 is increased on CD14 monocytes in early stages of MS.

    PubMed

    Vaknin-Dembinsky, Adi; Brass, Steven D; Brass, Steven; Gandhi, Roopali; Weiner, Howard L

    2008-03-01

    IL-15 is a pro-inflammatory cytokine whose three-dimensional structure is similar to that of IL-2. IL-2 and IL-15 have similar as well as distinct biological functions. An active form of IL-15 that is membrane bound has also been described. Furthermore, IL-15 is known to play a role in autoimmune diseases. We thus investigated the expression of membrane bound IL-15 on monocytes (CD14+ cells) and studied its effect on T cell activation in MS patients. We found that unstimulated CD14+ cells from relapsing remitting MS patients had increased membrane bound IL-15. Those with high surface levels of IL-15 on monocytes were in the early stages of the disease. In addition, we found that T cells of MS patients had enhanced responsiveness to IL-15 and there was increased expression of IL-15 receptor on CD4+ T cells. Thus, IL-15 may be an important cytokine that drives Th1 responses early in the course of the disease and could serve as a target for immunotherapy and as an early marker in the immunologic staging of MS.

  18. Discovery of piRNAs Pathway Associated with Early-Stage Spermatogenesis in Chicken.

    PubMed

    Xu, Lu; Qiu, Lingling; Chang, Guobin; Guo, Qixin; Liu, Xiangping; Bi, Yulin; Zhang, Yu; Wang, Hongzhi; Li, Zhiteng; Guo, Xiaoming; Wan, Fang; Zhang, Yang; Xu, Qi; Chen, Guohong

    2016-01-01

    Piwi-interacting RNAs (piRNAs) play a key role in spermatogenesis. Here, we describe the piRNAs profiling of primordial germ cells (PGCs), spermatogonial stem cells (SSCs), and the spermatogonium (Sp) during early-stage spermatogenesis in chicken. We obtained 31,361,989 reads from PGCs, 31,757,666 reads from SSCs, and 46,448,327 reads from Sp cells. The length distribution of piRNAs in the three samples showed peaks at 33 nt. The resulting genes were subsequently annotated against the Gene Ontology (GO) database. Five genes (RPL7A, HSPA8, Pum1, CPXM2, and PRKCA) were found to be involved in cellular processes. Interactive pathway analysis (IPA) further revealed three important pathways in early-stage spermatogenesis including the FGF, Wnt, and EGF receptor signaling pathways. The gene Pum1 was found to promote germline stem cell proliferation, but it also plays a role in spermatogenesis. In conclusion, we revealed characteristics of piRNAs during early spermatogonial development in chicken and provided the basis for future research.

  19. Astronomical constraints on the duration of the Early Jurassic Pliensbachian Stage and global climatic fluctuations

    NASA Astrophysics Data System (ADS)

    Ruhl, Micha; Hesselbo, Stephen P.; Hinnov, Linda; Jenkyns, Hugh C.; Xu, Weimu; Riding, James B.; Storm, Marisa; Minisini, Daniel; Ullmann, Clemens V.; Leng, Melanie J.

    2016-12-01

    The Early Jurassic was marked by multiple periods of major global climatic and palaeoceanographic change, biotic turnover and perturbed global geochemical cycles, commonly linked to large igneous province volcanism. This epoch was also characterised by the initial break-up of the super-continent Pangaea and the opening and formation of shallow-marine basins and ocean gateways, the timing of which are poorly constrained. Here, we show that the Pliensbachian Stage and the Sinemurian-Pliensbachian global carbon-cycle perturbation (marked by a negative shift in δ13 C of 2- 4 ‰), have respective durations of ∼8.7 and ∼2 Myr. We astronomically tune the floating Pliensbachian time scale to the 405 Kyr eccentricity solution (La2010d), and propose a revised Early Jurassic time scale with a significantly shortened Sinemurian Stage duration of 6.9 ± 0.4 Myr. When calibrated against the new time scale, the existing Pliensbachian seawater 87Sr/86Sr record shows relatively stable values during the first ∼2 Myr of the Pliensbachian, superimposed on the long-term Early Jurassic decline in 87Sr/86Sr. This plateau in 87Sr/86Sr values coincides with the Sinemurian-Pliensbachian boundary carbon-cycle perturbation. It is possibly linked to a late phase of Central Atlantic Magmatic Province (CAMP) volcanism that induced enhanced global weathering of continental crustal materials, leading to an elevated radiogenic strontium flux to the global ocean.

  20. Experimental early-stage coalification of a peat sample and a peatified wood sample from Indonesia

    USGS Publications Warehouse

    Orem, W.H.; Neuzil, S.G.; Lerch, H.E.; Cecil, C.B.

    1996-01-01

    Experimental coalification of a peat sample and a buried wood sample from domed peat deposits in Indonesia was carried out to examine chemical structural changes in organic matter during early-stage coalification. The experiment (125 C, 408 atm lithostatic pressure, and 177 atm fluid pressure for 75 days) was designed to maintain both lithostatic and fluid pressure on the sample, but allow by-products that may retard coalification to escape. We refer to this design as a geologically open system. Changes in the elemental composition, and 13C NMR and FTIR spectra of the peat and wood after experimental coalification suggest preferential thermal decomposition of O-containing aliphatic organic compounds (probably cellulose) during early-stage coalification. The elemental compositions and 13C NMR spectra of the experimentally coalified peat and wood were generally similar to those of Miocene coal and coalified wood samples from Indonesia. Yields of lignin phenols in the peat and wood samples decreased following experimental coalification; the wood sample exhibited a larger change. Lignin phenol yields from the experimentally coalified peat and wood were comparable to yields of lignin phenols from Miocene Indonesian lignite and coalified wood. Changes in syringyl/vanillyl and p-hydroxy/vanillyl ratios suggest direct demethoxylation as a secondary process to demethylation of methoxyl groups during early coalification, and changes in lignin phenol yields and acid/aldehyde ratios point to a coupling between demethoxylation processes and reactions in the alkyl side chain bonds of the ??-carbon in lignin phenols.

  1. Multitrait successional forest dynamics enable diverse competitive coexistence.

    PubMed

    Falster, Daniel S; Brännström, Åke; Westoby, Mark; Dieckmann, Ulf

    2017-03-10

    To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current niche models, which encode a very simplified view of plant communities, suggesting that the potential for niche differentiation has remained unexplored. Here, we show how extending successional niche models to include features common to all vegetation-height-structured competition for light under a prevailing disturbance regime and two trait-mediated tradeoffs in plant function-enhances the diversity of species that can be maintained, including a diversity of shade tolerants. We identify two distinct axes of potential niche differentiation, corresponding to the traits leaf mass per unit leaf area and height at maturation. The first axis allows for coexistence of different shade tolerances and the second axis for coexistence among species with the same shade tolerance. Addition of this second axis leads to communities with a high diversity of shade tolerants. Niche differentiation along the second axis also generates regions of trait space wherein fitness is almost equalized, an outcome we term "evolutionarily emergent near-neutrality." For different environmental conditions, our model predicts diverse vegetation types and trait mixtures, akin to observations. These results indicate that the outcomes of successional niche differentiation are richer than previously thought and potentially account for mixtures of traits and species observed in forests worldwide.

  2. Clearcut stand size and scrub-successional bird assemblages

    USGS Publications Warehouse

    Krementz, D.G.; Christie, J.S.

    2000-01-01

    We investigated the effects of clearcut stand size on species richness, reproductive effort, and relative abundance of scrub-successional birds and the entire bird assemblage at the Savannah River Site in South Carolina. We used standardized mist-net grids to mark and recapture birds in clearcuts replanted with longleaf pine (Pinus palustris) in stands of 2 to 57 ha that were two to six years old. Species richness for the entire bird assemblage was not explained by stand size (P = 0.67), stand age (P = 0.95), or the interaction of these two variables (P = 0.90). Similarly, species richness of scrub-successional birds was not explained by stand size (P = 0.63), stand age (P = 0.55), or the interaction of stand size and stand age (P = 0.35). Regressing species richness on clearcut stand size, we found a significant negative relationship between these variables for the entire bird assemblage (P = 0.01) and for scrub-successional birds (P = 0.02). The ratio of juveniles to adults in mist-net samples varied by year (P = 0.04), but neither clearcut size (P = 0.23) nor the interaction of clearcut size and year (P = 0.25) was related to the ratio of juveniles to adults in the sample. We found no relationship between the frequency of capture of any category of birds and stand size (scrub-successional, P = 0.52; woodland, P = 0.77; combined sample, P = 0.55). Neither bird-species richness, reproductive effort, nor relative abundance differed across clearcut stand sizes. Clearcut stand size does not appear to be an important management variable if variation in species richness, reproductive effort, or relative abundance are objectives. We suggest that even-aged forestry is a useful tool for managing birds in the southeastern United States.

  3. Multitrait successional forest dynamics enable diverse competitive coexistence

    PubMed Central

    Brännström, Åke; Westoby, Mark; Dieckmann, Ulf

    2017-01-01

    To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current niche models, which encode a very simplified view of plant communities, suggesting that the potential for niche differentiation has remained unexplored. Here, we show how extending successional niche models to include features common to all vegetation—height-structured competition for light under a prevailing disturbance regime and two trait-mediated tradeoffs in plant function—enhances the diversity of species that can be maintained, including a diversity of shade tolerants. We identify two distinct axes of potential niche differentiation, corresponding to the traits leaf mass per unit leaf area and height at maturation. The first axis allows for coexistence of different shade tolerances and the second axis for coexistence among species with the same shade tolerance. Addition of this second axis leads to communities with a high diversity of shade tolerants. Niche differentiation along the second axis also generates regions of trait space wherein fitness is almost equalized, an outcome we term “evolutionarily emergent near-neutrality.” For different environmental conditions, our model predicts diverse vegetation types and trait mixtures, akin to observations. These results indicate that the outcomes of successional niche differentiation are richer than previously thought and potentially account for mixtures of traits and species observed in forests worldwide. PMID:28283658

  4. Inhibitory bacteria reduce fungi on early life stages of endangered Colorado boreal toads (Anaxyrus boreas)

    PubMed Central

    Kueneman, Jordan G; Woodhams, Douglas C; Van Treuren, Will; Archer, Holly M; Knight, Rob; McKenzie, Valerie J

    2016-01-01

    Increasingly, host-associated microbiota are recognized to mediate pathogen establishment, providing new ecological perspectives on health and disease. Amphibian skin-associated microbiota interact with the fungal pathogen, Batrachochytrium dendrobatidis (Bd), but little is known about microbial turnover during host development and associations with host immune function. We surveyed skin microbiota of Colorado's endangered boreal toads (Anaxyrus boreas), sampling 181 toads across four life stages (tadpoles, metamorphs, subadults and adults). Our goals were to (1) understand variation in microbial community structure among individuals and sites, (2) characterize shifts in communities during development and (3) examine the prevalence and abundance of known Bd-inhibitory bacteria. We used high-throughput 16S and 18S rRNA gene sequencing (Illumina MiSeq) to characterize bacteria and microeukaryotes, respectively. Life stage had the largest effect on the toad skin microbial community, and site and Bd presence also contributed. Proteobacteria dominated tadpole microbial communities, but were later replaced by Actinobacteria. Microeukaryotes on tadpoles were dominated by the classes Alveolata and Stramenopiles, while fungal groups replaced these groups after metamorphosis. Using a novel database of Bd-inhibitory bacteria, we found fewer Bd-inhibitory bacteria in post-metamorphic stages correlated with increased skin fungi, suggesting that bacteria have a strong role in early developmental stages and reduce skin-associated fungi. PMID:26565725

  5. Organophosphorus pesticides effect on early stages of the axolotl Ambystoma mexicanum (Amphibia: Caudata).

    PubMed

    Robles-Mendoza, C; García-Basilio, C; Cram-Heydrich, S; Hernández-Quiroz, M; Vanegas-Pérez, C

    2009-02-01

    Ambystoma mexicanum is an endemic salamander of Xochimilco, a wetland of the basin of Mexico valley. Nowadays, axolotl populations are decreasing due environmental stressors. Particularly, studies about organophosphorus pesticides (OPPs; i.e. chlorpyrifos and malathion) toxicity are of great importance due to their intensive use in agricultural activities in Xochimilco. Thus, the aim of this study was to evaluate under controlled conditions the toxicity of chlorpyrifos (CPF) and malathion (MLT) on embryos and larvae (stage 44 and 54) of A. mexicanum. Embryos and larvae were exposure 96h from 0.5 to 3mg CPFL(-1) and from 10 to 30mg MLTL(-1) in independent tests. Embryos at the end of this period were maintained 9d without pesticide in order to identify possible recuperation. Differences obtained in mortality, hatching success, development, morphological abnormalities, behaviour and activity, suggest that toxicity of CPF and MLT differs in embryos and larval stages. Embryos were less sensitive to OPPs acute exposure than axolotl larvae; additionally, toxicity of CPF in larval stages was greater than MLT. On the other hand, data obtained in axolotl embryos during the period of recuperation to CPF in particular as delay and inhibition of development, malformations and success of hatching, indicated that these responses turned out more sensitive than mortality. This study allowed to identify the toxicological potential of OPPs on early developmental stages of A. mexicanum and it is a valuable contribution for the future management of the axolotl wild population.

  6. Facial affect recognition in early and late-stage schizophrenia patients.

    PubMed

    Romero-Ferreiro, María Verónica; Aguado, Luis; Rodriguez-Torresano, Javier; Palomo, Tomás; Rodriguez-Jimenez, Roberto; Pedreira-Massa, José Luis

    2016-04-01

    Prior studies have shown deficits in social cognition and emotion perception in first-episode psychosis (FEP) and multi-episode schizophrenia (MES) patients. These studies compared patients at different stages of the illness with only a single control group which differed in age from at least one clinical group. The present study provides new evidence of a differential pattern of deficit in facial affect recognition in FEP and MES patients using a double age-matched control design. Compared to their controls, FEP patients only showed impaired recognition of fearful faces (p=.007). In contrast to this, the MES patients showed a more generalized deficit compared to their age-matched controls, with impaired recognition of angry, sad and fearful faces (ps<.01) and an increased misattribution of emotional meaning to neutral faces. PANSS scores of FEP patients on Depressed factor correlated positively with the accuracy to recognize fearful expressions (r=.473). For the MES group fear recognition correlated positively with negative PANSS factor (r=.498) and recognition of sad and neutral expressions was inversely correlated with disorganized PANSS factor (r=-.461 and r=-.541, respectively). These results provide evidence that a generalized impairment of affect recognition is observed in advanced-stage patients and is not characteristic of the early stages of schizophrenia. Moreover, the finding that anomalous attribution of emotional meaning to neutral faces is observed only in MES patients suggests that an increased attribution of salience to social stimuli is a characteristic of social cognition in advanced stages of the disorder.

  7. Susceptibility of some vertebrate hosts to infection with early third-stage larvae of Gnathostoma hispidum.

    PubMed

    Sohn, W M; Lee, S H

    1997-09-01

    Susceptibility of some vertebrates was examined to the early third-stage larvae (EL3) of Gnathostoma hispidum. The larvae collected from the Chinese loaches were infected to 4 silk carps, 3 snake heads, 3 bullfrogs, 5 mice and 9 albino rats. No worms were detected in fish, silk carps and snake heads. In 3 bullfrogs fed 30 larvae, a total of 9 EL3 was recovered in the gastrointestinal tract (8 larvae) and liver (one). In 5 mice infected with 50 larvae, a total of 37 (74.0%) advanced third-stage larvae (AdL3) was recovered from the muscle (31 larvae), liver (5 larvae) and kidney at 4 weeks after infection. In 9 albino rats infected with 115 larvae, a total of 40 (34.8%) AdL3 was found in the muscle. The mammalian hosts were found susceptible to the EL3 of G. hispidum from Chinese loaches.

  8. Arthroscopic assisted bone grafting for early stages of Kienböck's disease.

    PubMed

    Pegoli, L; Ghezzi, A; Cavalli, E; Luchetti, R; Pajardi, G

    2011-01-01

    Kienböck's disease is known for its difficulty in being diagnosed and treated at early stages; option treatments are few and most of them quite aggressive. The author describes his experience with arthroscopic assisted lunate bone grafting. Three patients with diagnosis of stage I avascular necrosis of the lunate (average age: 45 years), were treated. Before surgical procedure, the patients underwent to a conservative treatment. After harvesting the bone graft from the volar surface of the radius, arthroscopic bone grafting was performed. At an average follow-up of 13.5 months (9-15), all the patients show a normal density of the lunate and no arthritic changes in radiographs. The MRI confirmed the lunate vascularity. The number of patients is definitely small, due also to the rarity of the disease and the difficulty in diagnosis, but, despite the very high learning curve, could be the proper first choice of treatment.

  9. Large scale surface migration of P. aeruginosa at early stages of biofilm formation

    NASA Astrophysics Data System (ADS)

    Gibiansky, Maxsim; Utada, Andy; Zhao, Kun; Xian, Wujing; Wong, Gerard

    2013-03-01

    Pseudomonas aeruginosa is a commonly-studied bacterium which can form biofilms, surface-bound aggregates which display increased resistance to various forms of stress, including a greatly enhanced antibiotic resistance. In the early stages of biofilm formation, free-swimming planktonic cells attach to the surface and form microcolonies, expressing a variety of adhesins and transitioning from reversible to irreversible attachment. By using particle tracking algorithms, we can in principle examine the full motility and division history of all cells in a microcolony. Here, we study the effects of the pel polysaccharides in microcolony formation by investigating how pel impacts the initial stages of biofilm formation by the P. aeruginosa PA14 strain. Specifically, we quantify the phenotypic effects of pel on initial attachment, microcolony formation, and biofilm morphology.

  10. Evaluation of the enhanced permeability and retention effect in the early stages of lymph node metastasis.

    PubMed

    Mikada, Mamoru; Sukhbaatar, Ariunbuyan; Miura, Yoshinobu; Horie, Sachiko; Sakamoto, Maya; Mori, Shiro; Kodama, Tetsuya

    2017-02-17

    Most solid cancers spread to new sites via the lymphatics before hematogenous dissemination. However, only a small fraction of an intravenously administered anti-cancer drug enters the lymphatic system to reach metastatic lymph nodes (LNs). Here, we show that the enhanced permeability and retention (EPR) effect is not induced during the early stages of LN metastasis. Luciferase-expressing tumor cells were injected into the subiliac LN of the MXH10/Mo-lpr/lpr mouse to induce metastasis to the proper axillary LN (PALN). In vivo biofluorescence imaging was used to confirm metastasis induction and to quantify the EPR effect, measured as PALN accumulation of intravenously injected indocyanine green (ICG) liposomes. PALN blood vessel volume changes were measured by contrast-enhanced high-frequency ultrasound imaging. The volume and density of blood vessels in the PALN increased until day 29 after inoculation whereas the LN volume remained constant. ICG retention was first detected on day 29 post-inoculation. While CD31-positive cells increased up to day 29 post-inoculation, α-smooth muscle actin-positive cells were detected on day 29 post-inoculation for the first time. These results suggest that the EPR effect was not induced in the early stages of LN metastasis; therefore, systemic chemotherapy would likely not be beneficial during the early stages of LN metastasis. The development of an alternative drug delivery system, independent of the EPR effect, is required for the treatment of LN metastasis. This article is protected by copyright. All rights reserved.

  11. Frequency of Early-Stage Lymphedema and Risk Factors in Postoperative Patients with Breast Cancer

    PubMed Central

    Soyder, Aykut; Taştaban, Engin; Özbaş, Serdar; Boylu, Şükrü; Özgün, Hedef

    2014-01-01

    Objective Lymphedema is a chronic major complication that is seen frequently post-operatively and has negative effects on quality of life. In our study, determining the early-stage postoperative lymphedema frequency and specifying the risk factors in its development has been aimed. Materials and Methods One hundred one cases that were operated on for breast cancer were evaluated regarding the 12-month control of their clinical specifications, histopathological specifications, and specifications related with the surgical intervention retrospectively. The data related to the parameters envisioned as risk factors were evaluated. Results Lymphedema development was found in 7 (6.9%) out of 101 cases constituting the study group. No significant difference (p>0.05) in terms of lymphedema development was determined among age, body mass index (BMI), chemotherapy (CT), postoperative seroma or infection, mastectomy with the dominant arm, and breast-conserving surgery (BCS), which were evaluated as risk factors. There was a significance (p<0.05) between the other risk factors, which were axillary dissection (AD), number of positive lymph nodes (LN), radiotherapy (RT), the tumor size (T), and lymphedema existence. In every case in which lymphedema was determined, it was seen that there was axillary LN involvement and 15≤LN were ablated in the dissection (p<0.05). Conclusion It is seen that AD, RT applied to the breast cancer patients, and T are important risk factors in early-stage lymphedema development. No early-stage lymphedema development was determined in any of the patients to whom sentinel lymph node dissection (SLND) was applied.

  12. Low-Dose Consolidation Radiation Therapy for Early Stage Unfavorable Hodgkin Lymphoma

    SciTech Connect

    Torok, Jordan A.; Wu, Yuan; Prosnitz, Leonard R.; Kim, Grace J.; Beaven, Anne W.; Diehl, Louis F.; Kelsey, Chris R.

    2015-05-01

    Purpose: The German Hodgkin Study Group (GHSG) trial HD11 established 4 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and 30 Gy of radiation therapy (RT) as a standard for early stage (I, II), unfavorable Hodgkin lymphoma (HL). Additional cycles of ABVD may allow for a reduction in RT dose and improved toxicity profile. Methods and Materials: Patients treated with combined modality therapy at the Duke Cancer Institute for early stage, unfavorable HL by GHSG criteria from 1994 to 2012 were included. Patients who did not undergo post-chemotherapy functional imaging (positron emission tomography or gallium imaging) or who failed to achieve a complete response were excluded. Clinical outcomes were estimated using the Kaplan-Meier method. Late effects were also evaluated. Results: A total of 90 patients met inclusion criteria for analysis. Median follow-up was 5 years. Chemotherapy consisted primarily of ABVD (88%) with a median number of 6 cycles. The median dose of consolidation RT was 23.4 Gy. Four patients had relapses, 2 of which were in-field. Ten-year progression-free survival (PFS) and overall survival (OS) were 93% (95% confidence interval [CI]: 0.82-0.97) and 98% (95% CI: 0.92-0.99), respectively. For the subset of patients (n=46) who received 5 to 6 cycles of chemotherapy and ≤24 Gy, the 10-year PFS and OS values were 88% (95% CI: 70%-96%) and 98% (95% CI: 85% - 99%), respectively. The most common late effect was hypothyroidism (20%) with no cardiac complications. Seven secondary malignancies were diagnosed, with only 1 arising within the RT field. Conclusions: Lower doses of RT may be sufficient when combined with more than 4 cycles of ABVD for early stage, unfavorable HL and may result in a more favorable toxicity profile than 4 cycles of ABVD and 30 Gy of RT.

  13. Early oligomerization stages for the non-amyloid component of α-synuclein amyloid

    NASA Astrophysics Data System (ADS)

    Eugene, Cindie; Laghaei, Rozita; Mousseau, Normand

    2014-10-01

    In recent years, much effort has focused on the early stages of aggregation and the formation of amyloid oligomers. Aggregation processes for these proteins are complex and their non-equilibrium nature makes any experimental study very difficult. Under these conditions, simulations provide a useful alternative for understanding the dynamics of the early stages of oligomerization. Here, we focus on the non-Aβ amyloid component (NAC) of the monomer, dimer, and trimer of α-synuclein, an important 35-residue sequence involved in the aggregation and fibrillation of this protein associated with Parkinson's disease. Using Hamiltonian and temperature replica exchange molecular dynamics simulations combined with the coarse grained Optimized Potential for Efficient peptide structure Prediction potential, we identify the role of the various regions and the secondary structures for the onset of oligomerization. For this sequence, we clearly observe the passage from α-helix to β-sheet, a characteristic transition of amyloid proteins. More precisely, we find that the NAC monomer is highly structured with two α-helical regions, between residues 2-13 and 19-25. As the dimer and trimer form, β-sheet structures between residues 2-14 and 26-34 appear and rapidly structure the system. The resulting conformations are much more structured than similar dimers and trimers of β-amyloid and amylin proteins and yet display a strong polymorphism at these early stages of aggregation. In addition to its inherent experimental interest, comparison with other sequences shows that NAC could be a very useful numerical model for understanding the onset of aggregation.

  14. Jasmonate signaling is activated in the very early stages of iron deficiency responses in rice roots.

    PubMed

    Kobayashi, Takanori; Itai, Reiko Nakanishi; Senoura, Takeshi; Oikawa, Takaya; Ishimaru, Yasuhiro; Ueda, Minoru; Nakanishi, Hiromi; Nishizawa, Naoko K

    2016-07-01

    Under low iron availability, plants induce the expression of various genes involved in iron uptake and translocation at the transcriptional level. This iron deficiency response is affected by various plant hormones, but the roles of jasmonates in this response are not well-known. We investigated the involvement of jasmonates in rice iron deficiency responses. High rates of jasmonate-inducible genes were induced during the very early stages of iron deficiency treatment in rice roots. Many jasmonate-inducible genes were also negatively regulated by the ubiquitin ligases OsHRZ1 and OsHRZ2 and positively regulated by the transcription factor IDEF1. Ten out of 35 genes involved in jasmonate biosynthesis and signaling were rapidly induced at 3 h of iron deficiency treatment, and this induction preceded that of known iron deficiency-inducible genes involved in iron uptake and translocation. Twelve genes involved in jasmonate biosynthesis and signaling were also upregulated in HRZ-knockdown roots. Endogenous concentrations of jasmonic acid and jasmonoyl isoleucine tended to be rapidly increased in roots in response to iron deficiency treatment, whereas these concentrations were higher in HRZ-knockdown roots under iron-sufficient conditions. Analysis of the jasmonate-deficient cpm2 mutant revealed that jasmonates repress the expression of many iron deficiency-inducible genes involved in iron uptake and translocation under iron sufficiency, but this repression is partly canceled under an early stage of iron deficiency. These results indicate that jasmonate signaling is activated during the very early stages of iron deficiency, which is partly regulated by IDEF1 and OsHRZs.

  15. Early-Stage Breast Cancer in the Octogenarian: Tumor Characteristics, Treatment Choices, and Clinical Outcomes

    PubMed Central

    Mamtani, Anita; Gonzalez, Julie J.; Neo, Dayna; Slanetz, Priscilla J.; Houlihan, Mary Jane; Herold, Christina I.; Recht, Abram; Hacker, Michele R.; Sharma, Ranjna

    2016-01-01

    Background Nodal staging with sentinel node biopsy (SLNB), post-lumpectomy radiotherapy (RT), and endocrine therapy (ET) for estrogen receptor-positive (ER+) tumors is valuable in the treatment of early-stage (stages 1 or 2) breast cancer but used less often for elderly women. Methods This retrospective study investigated women referred for surgical evaluation of biopsy-proven primary early-stage invasive breast cancer from January 2001 to December 2010. Clinicopathologic features, treatment course, and outcomes for women ages 80–89 years and 50–59 years were compared. Results The study identified 178 eligible women ages 80–89 years and 169 women ages 50–59 years. The elderly women more often had grade 1 or 2 disease (p = 0.003) and ER+ tumors (p = 0.007) and less frequently had undergone adjuvant therapies (all p ≤ 0.001). Lumpectomy was performed more commonly for the elderly (92 vs. 83 %, p = 0.02), and axillary surgery was less commonly performed (46 vs. 96 %; p < 0.001). Fewer elderly women had undergone post-lumpectomy RT (42 vs. 89 %; p < 0.001) and ET for ER+ tumors (72 vs. 95 %; p < 0.001). During the median follow-up period of 56 months for the 80- to 89-year old group and 98 months for the 50- to 59-year-old group, death from breast cancer was similar (4 vs. 5 %; p = 0.5). The two groups respectively experienced 7 versus 6 locoregional recurrences and 11 versus 13 distant recurrences. Conclusions The octogenarians had disease survivorship similar to that of the younger women despite less frequent use of adjuvant therapies, likely reflecting lower-risk disease features. Whether increased use of axillary surgery, post-lumpectomy RT, and/or ET for ER+ tumors would further improve outcomes is an important area for further study, but treatment should not be deferred solely on the basis of age. PMID:27364507

  16. Effect of ocean acidification on early life stages of Atlantic herring (Clupea harengus L.)

    NASA Astrophysics Data System (ADS)

    Franke, A.; Clemmesen, C.

    2011-12-01

    Due to atmospheric accumulation of anthropogenic CO2 the partial pressure of carbon dioxide (pCO2) in surface seawater increases and the pH decreases. This process known as ocean acidification might have severe effects on marine organisms and ecosystems. The present study addresses the effect of ocean acidification on early developmental stages, the most sensitive stages in life history, of the Atlantic herring (Clupea harengus L.). Eggs of the Atlantic herring were fertilized and incubated in artificially acidified seawater (pCO2 1260, 1859, 2626, 2903, 4635 μatm) and a control treatment (pCO2 480 μatm) until the main hatch of herring larvae occurred. The development of the embryos was monitored daily and newly hatched larvae were sampled to analyze their morphometrics, and their condition by measuring the RNA/DNA ratios. Elevated pCO2 neither affected the embryogenesis nor the hatch rate. Furthermore the results showed no linear relationship between pCO2 and total length, dry weight, yolk sac area and otolith area of the newly hatched larvae. For pCO2 and RNA/DNA ratio, however, a significant negative linear relationship was found. The RNA concentration at hatching was reduced at higher pCO2 levels, which could lead to a decreased protein biosynthesis. The results indicate that an increased pCO2 can affect the metabolism of herring embryos negatively. Accordingly, further somatic growth of the larvae could be reduced. This can have consequences for the larval fish, since smaller and slow growing individuals have a lower survival potential due to lower feeding success and increased predation mortality. The regulatory mechanisms necessary to compensate for effects of hypercapnia could therefore lead to lower larval survival. Since the recruitment of fish seems to be determined during the early life stages, future research on the factors influencing these stages are of great importance in fisheries science.

  17. Effects of temperature on early-life-history stages of California halibut Paralichthys californicus

    USGS Publications Warehouse

    Gadomski, D.M.; Caddell, S.M.

    1991-01-01

    - Laboratory experiments were conducted to determine how growth and survival of earlylife-history stages of California halibut Pamlichthys californicus are influenced by temperature, and how optimal temperature ranges may change with ontogeny. As halibut developed from eggs to juveniles, highest survival occurred at increasingly higher temperature ranges. Within tolerance limits, growth and development rates of all early-lifehistory stages were directly proportional to temperature. Eggs hatched successfully at 12, 16, and 20°C; at g and 24°C they died prior to embryo formation. Larval survival 17 days after hatching was 23-46% at 16, 20, and 24°C, but almost all larvae died at 12°C after an initial period of high survival. At gOC,larvai development ceased at the early yolksac stage. Survival of 3-month-old juvenile halibut was significantly greater at 20, 24. and 28°C (57-76°70) than at 16°C (31%). Temperature also affected settlement rate; when the temperature of I-month-old larvae was raised from 16°C to 20°C, settlement occurred about a week sooner than settlement of larvae remaining at 16°C. Tolerance ranges of halibut earlylife-history stages determined in the laboratory approximate temperatures encountered by halibut in the field; high densities of newly-settled halibut larvae and juveniles have been collected in shallow areas of bays where temperatures are often higher than the open ocean inhabited by young larvae. These warmer inshore nursery grounds could enhance growth and survival of halibut juveniles.

  18. Circulating and tissue biomarkers in early-stage non-small cell lung cancer

    PubMed Central

    Fumagalli, Caterina; Bianchi, Fabrizio; Raviele, Paola Rafaniello; Vacirca, Davide; Bertalot, Giovanni; Rampinelli, Cristiano; Lazzeroni, Matteo; Bonanni, Bernardo; Veronesi, Giulia; Fusco, Nicola; Barberis, Massimo; Guerini-Rocco, Elena

    2017-01-01

    Objective We sought to characterise circulating and tissue tumour biomarkers of patients who developed early-stage non-small cell lung cancer (NSCLC) during long-term follow-up of a chemoprevention trial (NCT00321893). Materials and Methods Blood and sputum samples were collected from 202 high-risk asymptomatic individuals with CT-detected stable lung nodules. Real-time PCR was performed on plasma to quantify free circulating DNA. Baseline serum was investigated with a previously validated test based on 13 circulating miRNAs (miR-Test). Promoter methylation status of p16, RASSF1a and RARβ2 and telomerase activity were assessed in sputum samples. DNA was extracted from each tumour developed during follow-up and subjected to a mutation survey using the LungCarta panel on the Sequenom MassARRAY platform. Results During follow-up (9 years) six individuals underwent surgery for stage I NSCLC with a median time of disease onset of 20.5 months. MiR-Test scores were positive (range: 0.14–7.24) in four out of six baseline pre-disease onset sera. No association was identified between free circulating DNA or sputum biomarkers and disease onset. All tumours harboured at least one somatic mutation in well-known cancer genes, including KRAS (n = 4), BRAF (n = 1), and TP53 (n = 3). Conclusion Circulating miRNA tests may represent valuable tools to detect clinically-silent tumours. Early-stage lung adenocarcinomas harbour recurrent genetic events similar to those described in advanced-stage NSCLCs. PMID:28194229

  19. Biopsy Findings After Breast Conservation Therapy for Early-Stage Invasive Breast Cancer

    SciTech Connect

    Vapiwala, Neha Starzyk, Jill; Harris, Eleanor E.; Tchou, Julia C.; Boraas, Marcia C.; Czerniecki, Brian J.; Rosato, Ernest F.; Orel, Susan G.; Solin, Lawrence J.

    2007-10-01

    Purpose: To determine the patterns and factors predictive of positive ipsilateral breast biopsy after conservation therapy for early-stage breast cancer. Methods and Materials: We performed a retrospective review of Stage I-II breast cancer patients initially treated with lumpectomy and radiotherapy between 1977 and 1996, who later underwent post-treatment ipsilateral breast biopsies. Results: A total of 223 biopsies were performed in 193 treated breasts: 171 single and 22 multiple biopsies. Of the 223 biopsies, 56% were positive and 44% were negative for recurrence. The positive biopsy rate (PBR) was 59% for the first and 32% for subsequent biopsies. The median time to the first post-treatment biopsy was 49 months. Of the patients with negative initial biopsy findings, 11% later developed local recurrence. The PBR was 40% among patients with physical examination findings only, 65% with mammographic abnormalities only, and 79% with both findings (p = 0.001). Analysis of the procedure type revealed a PBR of 86% for core and 58% for excisional biopsies compared with 28% for aspiration cytology alone (p = 0.025). The PBR varied inversely with age at the original diagnosis: 49% if {>=}51 years, 57% if 36-50 years, and 83% if {<=}35 years (p = 0.05). The PBR correlated directly with the interval after radiotherapy: 49% if {<=}60 months, 59% if 60.1-120 months, 77% if 120.1-180 months, and 100% if >180 months after completing postlumpectomy radiotherapy (p = 0.01). The PBR was not linked with recurrence location, initial pathologic T or N stage, estrogen receptor/progesterone receptor status, or final pathologic margins (all p {>=} 0.15). Conclusion: After definitive radiotherapy for early-stage breast cancer, a greater PBR was associated with the presence of both mammographic and clinical abnormalities, excisional or core biopsies, younger age at the initial diagnosis, and longer intervals after radiotherapy completion.

  20. 'Making the best you can of it': living with early-stage Alzheimer's disease.

    PubMed

    Macrae, Hazel

    2008-04-01

    Drawing upon data from a qualitative study of persons who are in the early stage of the condition, this paper examines the meaning of Alzheimer's disease. It contrasts the meaning of the disease as portrayed in popular culture with its meaning as interpreted by persons living with it. Findings show that persons with the illness do not necessarily accept the negative cultural meaning of the disease, nor the helpless 'victim' role in which they are generally cast. With a determination to 'make the best of it', strategies such as humour, normalisation, present-time orientation, and life review are employed to create a meaningful life.

  1. Clean Energy Finance: Challenges and Opportunities of Early-Stage Energy Investing (Presentation)

    SciTech Connect

    Heap, D.; Pless, J.; Aieta, N.

    2013-12-01

    Characterized by a changing landscape and new opportunities, today's increasingly complex energy decision space will need innovative financing and investment models to appropriately assess risk and profitability. This report provides an overview of the current state of clean energy finance across the entire spectrum but with a focus on early stage investing, and it includes insights from investors across all investment classes. Further, this report aims to provide a roadmap with the mechanisms, limitations, and considerations involved in making successful investments by identifying risks, challenges, and opportunities in the clean energy sector.

  2. A Model of Isotope Separation in Cells at the Early Stages of Evolution.

    PubMed

    Melkikh, A V; Bokunyaeva, A O

    2016-03-01

    The separation of the isotopes of certain ions can serve as an important criterion for the presence of life in the early stages of its evolution. A model of the separation of isotopes during their transport through the cell membrane is constructed. The dependence of the selection coefficient on various parameters is found. In particular, it is shown that the maximum efficiency of the transport of ions corresponds to the minimum enrichment coefficient. At the maximum enrichment, the efficiency of the transport system approaches ½. Calculated enrichment coefficients are compared with experimentally obtained values for different types of cells, and the comparison shows a qualitative agreement between these quantities.

  3. Origin of the Directed Movement of Protocells in the Early Stages of the Evolution of Life

    NASA Astrophysics Data System (ADS)

    Melkikh, Alexey V.; Chesnokova, Oksana I.

    2012-08-01

    The origin of the directed motion of protocells during the early stages of evolution was discussed. The expenditures for movement, space orientation, and reception of information about the environment were taken into consideration, and it was shown that directed movement is evolutionarily advantageous in the following cases: when opposite gradients of different resources (for example, matter and energy) are great enough and when there is a rapid change in environmental parameters. It was also shown that the advantage of directed movement strategies depends greatly on how information about the environment is obtained by a protocell.

  4. Histopathologic findings of spontaneous osteonecrosis of the knee at an early stage: a case report.

    PubMed

    Hatanaka, Hiroyuki; Yamamoto, Takuaki; Motomura, Goro; Sonoda, Kazuhiko; Iwamoto, Yukihide

    2016-05-01

    We histopathologically examined a surgically resected full specimen obtained from an early-stage spontaneous osteonecrosis of the knee (SPONK). On a mid-coronal cut section of the resected medial femoral condyle, a linear fracture line paralleling the subchondral bone endplate was found. Histopathologically, prominent callus formation was seen comprising of reactive woven bone and granulation tissue on both sides of the fracture. Fracture-related bone debris was focally observed at the osteochondral side of the fracture. Definitive features of antecedent bone infarction such as creeping substitution and bone marrow necrosis were not detected. These findings suggested that SPONK was the result of a subchondral fracture rather than primary osteonecrosis.

  5. Early-Stage Folding in Proteins (In Silico) Sequence-to-Structure Relation

    PubMed Central

    2005-01-01

    A sequence-to-structure library has been created based on the complete PDB database. The tetrapeptide was selected as a unit representing a well-defined structural motif. Seven structural forms were introduced for structure classification. The early-stage folding conformations were used as the objects for structure analysis and classification. The degree of determinability was estimated for the sequence-to-structure and structure-to-sequence relations. Probability calculus and informational entropy were applied for quantitative estimation of the mutual relation between them. The structural motifs representing different forms of loops and bends were found to favor particular sequences in structure-to-sequence analysis. PMID:16046811

  6. Influence of secondary structure on recovery from pauses during early stages of RNA transcription.

    PubMed

    Klopper, A V; Bois, J S; Grill, S W

    2010-03-01

    The initial stages of transcription by RNA polymerase are frequently marked by pausing and stalling events. These events have been linked to an inactive backtracked state in which the polymerase diffuses along the template DNA. We investigate theoretically the influence of RNA secondary structure in confining this diffusion. The effective confinement length peaks at transcript lengths commensurate with early stalling. This finite-size effect accounts for slow progress at the beginning of transcription, which we illustrate via stochastic hopping models for backtracking polymerases.

  7. Influence of secondary structure on recovery from pauses during early stages of RNA transcription

    NASA Astrophysics Data System (ADS)

    Klopper, A. V.; Bois, J. S.; Grill, S. W.

    2010-03-01

    The initial stages of transcription by RNA polymerase are frequently marked by pausing and stalling events. These events have been linked to an inactive backtracked state in which the polymerase diffuses along the template DNA. We investigate theoretically the influence of RNA secondary structure in confining this diffusion. The effective confinement length peaks at transcript lengths commensurate with early stalling. This finite-size effect accounts for slow progress at the beginning of transcription, which we illustrate via stochastic hopping models for backtracking polymerases.

  8. Nonlinear Langevin model for the early-stage dynamics of electrospinning jets

    NASA Astrophysics Data System (ADS)

    Lauricella, Marco; Pontrelli, Giuseppe; Pisignano, Dario; Succi, Sauro

    2015-09-01

    We present a nonlinear Langevin model to investigate the early-stage dynamics of electrified polymer jets in electrospinning experiments. In particular, we study the effects of air drag force on the uniaxial elongation of the charged jet, right after ejection from the nozzle. Numerical simulations show that the elongation of the jet filament close to the injection point is significantly affected by the nonlinear drag exerted by the surrounding air. These results provide useful insights for the optimal design of current and future electrospinning experiments.

  9. Effects of Offshore Wind Farms on the Early Life Stages of Dicentrarchus labrax.

    PubMed

    Debusschere, Elisabeth; De Coensel, Bert; Vandendriessche, Sofie; Botteldooren, Dick; Hostens, Kris; Vincx, Magda; Degraer, Steven

    2016-01-01

    Anthropogenically generated underwater noise in the marine environment is ubiquitous, comprising both intense impulse and continuous noise. The installation of offshore wind farms across the North Sea has triggered a range of ecological questions regarding the impact of anthropogenically produced underwater noise on marine wildlife. Our interest is on the impact on the "passive drifters," i.e., the early life stages of fish that form the basis of fish populations and are an important prey for pelagic predators. This study deals with the impact of pile driving and operational noise generated at offshore wind farms on Dicentrarchus labrax (sea bass) larvae.

  10. A case of painless thyroiditis in a very early stage of pregnancy.

    PubMed

    Sato, Shiori; Endo, Kei; Iizaka, Toru; Saiki, Ryo; Iwaku, Kenji; Sato, Shotaro; Takahashi, Yasuyoshi; Otsuka, Fumiko; Taniyama, Matsuo

    2012-01-01

    We report a case of painless thyroiditis detected during the first trimester of pregnancy. A 29-year-old Japanese woman was hospitalized because of thyrotoxicosis and she was confirmed to be pregnant. The gestational age was 4 weeks. Blood examinations revealed negative TSH receptor antibodies, however, we started potassium iodide because we were unable to rule out Graves' disease. Thyroid hormone levels were normalized in 3 weeks and remained low even after discontinuation of medication. She received replacement therapy with levothyroxine sodium hydrate till 3 months after delivery. Painless thyroiditis can be one of the differential diagnoses of thyrotoxicosis in a very early stage of pregnancy.

  11. Impact of [{sup 18}F] Fluorodeoxyglucose Positron Emission Tomography on Staging and Management of Early-Stage Follicular Non-Hodgkin Lymphoma

    SciTech Connect

    Wirth, Andrew Foo, Marcus; Seymour, John F.; MacManus, Michael P.; Hicks, Rodney J.

    2008-05-01

    Purpose: Accurate staging is critical to select patients with early-stage (I-II) follicular lymphoma (ESFL) suitable for involved-field radiotherapy (IFRT) and to define the radiotherapy portal. We evaluated the impact of fluorodeoxyglucose (FDG) PET on staging, treatment, and outcome for patients with ESFL on conventional staging. Methods and Materials: Forty-two patients with untreated ESFL (World Health Organization Grade I-IIIa, or 'low grade') following a minimum of physical examination, computerized tomography, and bone marrow examination (conventional assessment) and who had staging PET from June 1997 to June 2006 were studied retrospectively. Stage allocation was based on routine imaging reports. Disease sites, stage, and management plan were recorded based on conventional assessment or conventional assessment plus PET. Results: FDG avidity was demonstrated in 97% of patients in whom disease was evident on conventional assessment after biopsy. PET findings suggested a change of stage or management in 19 patients: 13 (31%) who were upstaged to Stage III-IV, altering ideal management from IFRT to systemic therapy, and 6 (14%) who had the involved field enlarged, including 4 upstaged from Stage I to II. Of these 19 cases, PET findings were considered true positive in 8 patients, indeterminate in 10, and false positive in only 1 patient. Conclusions: Our data confirm that ESFL is usually FDG-avid. In routine practice, PET has the potential to upstage and thereby alter management in a high proportion of patients with apparent ESFL.

  12. Adventitial fibroblasts are activated in the early stages of atherosclerosis in the apolipoprotein E knockout mouse

    SciTech Connect

    Xu Fang; Ji Jian; Li Li; Chen Rong; Hu Weicheng . E-mail: huweicheng@sdu.edu.cn

    2007-01-19

    The role of the adventitia in vascular function and vascular lesion formation has been largely ignored. This study observed the activation of the adventitia and specifically the fibroblasts in the development of atherosclerosis in the apoE(-/-) mouse. The results showed a gradual increase in expression of collagen types I and III after 2, 4, and 8 weeks of hyperlipidic diet. The earliest expression of monocyte chemoattractant protein-1 (MCP-1) protein and mRNA was detected in the adventitial fibroblast before the formation of intimal lesions. Proliferation, too, was first found in the adventitial fibroblasts. We hypothesize that the adventitial fibroblast is activated in the early stage of atherosclerosis. Adventitial inflammation may be an early event in the development of atherosclerotic lesions.

  13. Selective attention to signs of success: social dominance and early stage interpersonal perception.

    PubMed

    Maner, Jon K; DeWall, C Nathan; Gailliot, Matthew T

    2008-04-01

    Results from two experiments suggest that observers selectively attend to male, but not female, targets displaying signs of social dominance. Participants overestimated the frequency of dominant men in rapidly presented stimulus arrays (Study 1) and visually fixated on dominant men in an eyetracking experiment (Study 2). When viewing female targets, participants attended to signs of physical attractiveness rather than social dominance. Findings fit with evolutionary models of mating, which imply that dominance and physical attractiveness sometimes tend to be prioritized preferentially in judgments of men versus women, respectively. Findings suggest that sex differences in human mating are observed not only at the level of overt mating preferences and choices but also at early stages of interpersonal perception. This research demonstrates the utility of examining early-in-the-stream social cognition through the functionalist lens of adaptive thinking.

  14. The relationship between cortisol and verbal memory in the early stages of Huntington's disease.

    PubMed

    Shirbin, Christopher A; Chua, Phyllis; Churchyard, Andrew; Hannan, Anthony J; Lowndes, Georgia; Stout, Julie C

    2013-03-01

    Hypothalamic pituitary adrenal (HPA) axis hyperactivity has been linked to learning and memory difficulties in a range of neurodegenerative and neuropsychiatric conditions. In Huntington's disease (HD), both declines in learning and memory and HPA axis dysfunction are present early in the disease. However, the relationship between specific learning and memory deficits and HPA axis functioning in HD has not been examined. The aim of this study was to investigate cortisol levels in relation to verbal learning and memory in pre-diagnosed (pre-HD) participants and patients at the early stages of diagnosed HD (early-HD). Cortisol concentration was assayed in saliva samples from 57 participants (17 early-HD, 20 pre-HD, and 20 controls) at four time-points across a 24-h period. Verbal memory was assessed using the California Verbal Learning Test-Second Edition (CVLT-II). We focused statistical analyses on the late evening cortisol concentration, and examined cortisol levels and verbal memory function in relation to diagnostic group (control, pre-HD, early-HD), and in a separate set of analyses combining pre-HD and early-HD (and excluding controls) we also examined cortisol and verbal memory performance in relation to the severity of HD-related motor signs. Of these two classification approaches, HD motor sign severity was more strongly associated with high evening cortisol levels and both reduced information encoding and memory retrieval. Separately, there was also a trend of higher cortisol levels in pre-HD. The findings suggest hypercortisolism and the underlying pathological changes may begin many years before a clinical diagnosis is made, but the memory decline associated with HPA axis disturbance may only become detectable once motor signs become pronounced.

  15. Parallel processing of general and specific threat during early stages of perception

    PubMed Central

    2016-01-01

    Differential processing of threat can consummate as early as 100 ms post-stimulus. Moreover, early perception not only differentiates threat from non-threat stimuli but also distinguishes among discrete threat subtypes (e.g. fear, disgust and anger). Combining spatial-frequency-filtered images of fear, disgust and neutral scenes with high-density event-related potentials and intracranial source estimation, we investigated the neural underpinnings of general and specific threat processing in early stages of perception. Conveyed in low spatial frequencies, fear and disgust images evoked convergent visual responses with similarly enhanced N1 potentials and dorsal visual (middle temporal gyrus) cortical activity (relative to neutral cues; peaking at 156 ms). Nevertheless, conveyed in high spatial frequencies, fear and disgust elicited divergent visual responses, with fear enhancing and disgust suppressing P1 potentials and ventral visual (occipital fusiform) cortical activity (peaking at 121 ms). Therefore, general and specific threat processing operates in parallel in early perception, with the ventral visual pathway engaged in specific processing of discrete threats and the dorsal visual pathway in general threat processing. Furthermore, selectively tuned to distinctive spatial-frequency channels and visual pathways, these parallel processes underpin dimensional and categorical threat characterization, promoting efficient threat response. These findings thus lend support to hybrid models of emotion. PMID:26412811

  16. Macrophage migration inhibitory factor (MIF): genetic evidence for participation in early onset and early stage rheumatoid arthritis

    PubMed Central

    Llamas-Covarrubias, MA; Valle, Y; Bucala, R; Navarro-Hernández, RE; Palafox-Sánchez, CA; Padilla-Gutiérrez, JR; Parra-Rojas, I; Bernard-Medina, AG; Reyes-Castillo, Z; Muñoz-Valle, JF

    2013-01-01

    Macrophage migration inhibitory factor (MIF) is an upstream pro-inflammatory cytokine that is associated with the pathogenesis of autoimmune inflammatory diseases including rheumatoid arthritis (RA).Two polymorphisms in the upstream region exist in the MIF gene and are associated with RA susceptibility or severity in different populations. In this case-control study, we investigated whether MIF polymorphisms are associated with RA susceptibility or activity in a western Mexican population .The relationship of MIF levels with clinical features of disease also was assessed. Genotyping of the -794 CATT5-8(rs5844572) and the -173 G>C (s755622) polymorphisms was performed by PCR and PCR-RFLP respectively on 226 RA patients and 210 healthy subjects. Serum MIF levels were determined by ELISA. We found a significant association between the -794 CATT5-8 6,7 MIF genotype with RA. Moreover, we detected an association between the -794 CATT7 allele with early onset RA. The -794 CATT7 and -173*C alleles, which are in linkage disequilibrium, were associated with high disease activityon RA patients. A positive correlation between circulating MIF levels and C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor, anti-citrullinated protein/peptides antibodies and TNFα was detected. MIF levels appear to be associated with disease progression rather than disease activity, which is distinct from the established relationship between disease activity and TNFα levels. In conclusion, the MIF gene and protein are associated with RA in a western Mexican population, with a main contribution onto early onset and early stages of disease. PMID:23402792

  17. Early results of neurodevelopment following hybrid stage I for hypoplastic left heart syndrome.

    PubMed

    Cheatham, Sharon L; Carey, Helen; Chisolm, Joanne L; Heathcock, Jill C; Steward, Deborah

    2015-03-01

    Motor skills and neurodevelopment in infants with hypoplastic left heart syndrome (HLHS) who have undergone Hybrid Stage I palliation is unknown. The purpose of this study is to assess early neurodevelopment in infants with HLHS after Hybrid Stage I palliation. Developmental assessment was performed in HLHS infants who underwent Hybrid Stage I palliation at 2 and 4 months of age using the Test of Infant Motor Performance, and at 6 months of age, prior to undergoing the second staged surgery, using the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III). Results were compared to healthy control subjects and norm-referenced data. The HLHS group scored between -1 and -2 standard deviations (SD) below the mean at 2 months of age (p = 0.002), and within -1 SD of the mean, at 4 months of age (p = 0.0019), on the TIMP. Compared to the control group, composite motor skills were significantly lower at 6 months of age on the Bayley-III in the HLHS group (p = 0.0489), however, not significant for cognitive (p = 0.29) or language (p = 0.68). Percentile rank motor scores were 17 ± 20 % in the HLHS group compared to 85 ± 12 % for the healthy age-matched control group. Infants with HLHS who undergo Hybrid Stage I palliation score lower on standardized motor skill tests compared to healthy age-matched controls and the norm-referenced population. This suggests that infants with HLHS have poorer motor skill performance than typically developing infants at 6 months of age.

  18. Development of cryopreservation protocols for early stage zebrafish (Danio rerio) ovarian follicles using controlled slow cooling.

    PubMed

    Tsai, S; Rawson, D M; Zhang, T

    2009-05-01

    Cryopreservation of germplasm of aquatic species offers many benefits to the fields of aquaculture, conservation and biomedicine. Although successful fish sperm cryopreservation has been achieved with many species, there has been no report of successful cryopreservation of fish embryos and late stage oocytes which are large, chilling sensitive and have low membrane permeability. In the present study, cryopreservation of early stage zebrafish ovarian follicles was studied for the first time using controlled slow freezing. The effect of cryoprotectant, freezing medium, cooling rate, method for cryoprotectant removal, post-thaw incubation time and ovarian follicle developmental stage were investigated. Stages I and II ovarian follicles were frozen in 4M methanol and 3M DMSO in either L-15 medium or KCl buffer. Ovarian follicle viability was assessed using trypan blue, FDA+PI staining and ADP/ATP assay. The results showed that KCl buffer was more beneficial than L-15 medium, methanol was more effective than DMSO, optimum cooling rates were 2-4 degrees C/min, stepwise removal of cryoprotectant improved ovarian follicle viability significantly and stage I ovarian follicles were more sensitive to freezing. The results also showed that FDA+PI staining and ADP/ATP assay were more sensitive than TB staining. The highest follicle viabilities after post-thaw incubation for 2h obtained with FDA+PI staining were 50.7+/-4.0% although ADP/ATP ratios of the cryopreserved follicles were significantly increased indicating increased cell damage. Studies are currently being carried out on in vitro maturation of these cryopreserved ovarian follicles.

  19. Targeted labeling of an early-stage tumor spheroid in a chorioallantoic membrane model with upconversion nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Holz, Jasmin A.; Ding, Yadan; Liu, Xiaomin; Zhang, Youlin; Tu, Langping; Kong, Xianggui; Priem, Bram; Nadort, Annemarie; Lambrechts, Saskia A. G.; Aalders, Maurice C. G.; Buma, Wybren Jan; Liu, Yichun; Zhang, Hong

    2015-01-01

    In vivo detection of cancer at an early-stage, i.e. smaller than 2 mm, is a challenge in biomedicine. In this work target labeling of an early-stage tumor spheroid (~500 μm) is realized for the first time in a chick embryo chorioallantoic membrane (CAM) model with monoclonal antibody functionalized upconversion nanoparticles (UCNPs-mAb).In vivo detection of cancer at an early-stage, i.e. smaller than 2 mm, is a challenge in biomedicine. In this work target labeling of an early-stage tumor spheroid (~500 μm) is realized for the first time in a chick embryo chorioallantoic membrane (CAM) model with monoclonal antibody functionalized upconversion nanoparticles (UCNPs-mAb). Electronic supplementary information (ESI) available: Details of experimental procedures for the sample preparation and characterization, Chick CAM model, 3-D multicellular tumor spheroids, UCNPs circulating in CAM. See DOI: 10.1039/c4nr05638h

  20. Effect of light Sphagnum peat on odour formation in the early stages of biowaste composting.

    PubMed

    Kurola, Jukka M; Arnold, Mona; Kontro, Merja H; Talves, Matti; Romantschuk, Martin

    2010-05-01

    In the present study, we investigated the effects of two bulking materials, Sphagnum peat and pine wood chips, on the early stages of biowaste composting in two pilot-scale processes. Emphasis was placed on studying the formation conditions of malodorous compost gases in the initial phases of the processes. The results showed that gas emission leaving an open windrow and a closed drum composting system contained elevated concentrations of fermentative microbial metabolites when acid Sphagnum peat (pH 3.2) was used as a bulking material. Moreover, the gas emission of the peat amended drum composter contained a high concentration of odour (up to 450,000oum(-3) of air). The highest odour values in the outlet gas of peat amended composts coincided with the elevated concentrations of volatile organic compounds such as acetoin and buthanedion. We conclude that the acidifying qualities of composting substrates or bulking material may intensify odour emission from biowaste composts and prolong the early stages of the composting process.

  1. Raman spectroscopy based investigation of molecular changes associated with an early stage of dengue virus infection

    NASA Astrophysics Data System (ADS)

    Bilal, Maria; Bilal, Muhammad; Saleem, Muhammad; Khurram, Muhammad; Khan, Saranjam; Ullah, Rahat; Ali, Hina; Ahmed, Mushtaq; Shahzada, Shaista; Ullah Khan, Ehsan

    2017-04-01

    Raman spectroscopy based investigations of the molecular changes associated with an early stage of dengue virus infection (DENV) using a partial least squares (PLS) regression model is presented. This study is based on non-structural protein 1 (NS1) which appears after three days of DENV infection. In total, 39 blood sera samples were collected and divided into two groups. The control group contained samples which were the negative for NS1 and antibodies and the positive group contained those samples in which NS1 is positive and antibodies were negative. Out of 39 samples, 29 Raman spectra were used for the model development while the remaining 10 were kept hidden for blind testing of the model. PLS regression yielded a vector of regression coefficients as a function of Raman shift, which were analyzed. Cytokines in the region 775–875 cm‑1, lectins at 1003, 1238, 1340, 1449 and 1672 cm‑1, DNA in the region 1040–1140 cm‑1 and alpha and beta structures of proteins in the region 933–967 cm‑1 have been identified in the regression vector for their role in an early stage of DENV infection. Validity of the model was established by its R-square value of 0.891. Sensitivity, specificity and accuracy were 100% each and the area under the receiver operator characteristic curve was found to be 1.

  2. Embryotoxicity of nitrophenols to the early life stages of zebrafish (Danio rerio).

    PubMed

    Ceylan, Zeynep; Şişman, Turgay; Yazıcı, Zehra; Altıkat, Aysun Özen

    2016-08-01

    The nitrophenols (NPs) are water-soluble compounds. These compounds pose a significant health threat since they are priority environmental pollutants. In this study, 2-Nitrophenol (2NP) and 2,4-dinitrophenol (DNP) were examined for embryo and early life stage toxicity in zebrafish (Danio rerio). Acute toxicity and teratogenicity of 2NP and DNP were tested for 4 days using zebrafish embryos. The typical lesions observed were no somite formation, incomplete eye and head development, tail curvature, weak pigmentation (≤48 hours postfertilization (hpf)), kyphosis, scoliosis, yolk sac deformity, and nonpigmentation (72 hpf). Also, embryo and larval mortality increased and hatching success decreased. The severity of abnormalities and mortalities were concentration- and compound-dependent. Of the compounds tested, 2,4-DNP was found to be highly toxic to the fish embryos following exposure. The median lethal concentrations and median effective concentrations for 2NP are 18.7 mg/L and 7.9 mg/L, respectively; the corresponding values for DNP are 9.65 mg/L and 3.05 mg/L for 48 h. The chorda deformity was the most sensitive endpoint measured. It is suggested that the embryotoxicity may be mediated by an oxidative phosphorylation uncoupling mechanism. This article is the first to describe the teratogenicity and embryotoxicity of two NPs to the early life stages of zebrafish.

  3. Genetic identification of female Cannabis sativa plants at early developmental stage.

    PubMed

    Techen, Natascha; Chandra, Suman; Lata, Hemant; Elsohly, Mahmoud A; Khan, Ikhlas A

    2010-11-01

    Sequence-characterized amplified region (SCAR) markers were used to identify female plants at an early developmental stage in four different varieties of Cannabis sativa. Using the cetyl trimethylammonium bromide (CTAB) method, DNA was isolated from two-week-old plants of three drug-type varieties (Terbag W1, Terbag K2, and Terbag MX) and one fiber-type variety (Terbag Fedora A7) of C. sativa grown under controlled environmental conditions through seeds. Attempts to use MADC2 (male-associated DNA from Cannabis sativa) primers as a marker to identify the sex of Cannabis sativa plants were successful. Amplification of genomic DNA using MADC2-F and MADC2-R primers produced two distinct fragments, one with a size of approximately 450 bp for female plants and one for male plants with a size of approximately 300 bp. After harvesting the tissues for DNA extraction, plants were subjected to a flowering photoperiod (i.e., 12-h light cycle), and the appearance of flowers was compared with the DNA analysis. The results of the molecular analysis were found to be concordant with the appearance of male or female flowers. The results of this study represent a quick and reliable technique for the identification of sex in Cannabis plants using SCAR markers at a very early developmental stage.

  4. Towards non-invasive diagnostic imaging of early-stage Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Viola, Kirsten L.; Sbarboro, James; Sureka, Ruchi; de, Mrinmoy; Bicca, Maíra A.; Wang, Jane; Vasavada, Shaleen; Satpathy, Sreyesh; Wu, Summer; Joshi, Hrushikesh; Velasco, Pauline T.; Macrenaris, Keith; Waters, E. Alex; Lu, Chang; Phan, Joseph; Lacor, Pascale; Prasad, Pottumarthi; Dravid, Vinayak P.; Klein, William L.

    2015-01-01

    One way to image the molecular pathology in Alzheimer's disease is by positron emission tomography using probes that target amyloid fibrils. However, these fibrils are not closely linked to the development of the disease. It is now thought that early-stage biomarkers that instigate memory loss are composed of Aβ oligomers. Here, we report a sensitive molecular magnetic resonance imaging contrast probe that is specific for Aβ oligomers. We attach oligomer-specific antibodies onto magnetic nanostructures and show that the complex is stable and binds to Aβ oligomers on cells and brain tissues to give a magnetic resonance imaging signal. When intranasally administered to an Alzheimer's disease mouse model, the probe readily reached hippocampal Aβ oligomers. In isolated samples of human brain tissue, we observed a magnetic resonance imaging signal that distinguished Alzheimer's disease from controls. Such nanostructures that target neurotoxic Aβ oligomers are potentially useful for evaluating the efficacy of new drugs and ultimately for early-stage Alzheimer's disease diagnosis and disease management.

  5. Neck circumference and early stage atherosclerosis: the cardiometabolic risk in Chinese (CRC) study

    PubMed Central

    2014-01-01

    Background Neck circumference (NC) has been previously related to cardiometabolic risk factors. In this study we examined the association between NC and early stage atherosclerosis in Chinese adults. Methods The study samples were from a community-based health examination survey in central China. In total 2,318 men and women (18-64 y) were included in the final analyses. Carotid radial pulse wave velocity (crPWV), carotid femoral PWV (cfPWV), carotid artery dorsalis pedis PWV (cdPWV) and NC were measured. Results After adjustment for age, sex, lipids, glucose, blood pressure, heart rate, body mass index (BMI), high NC was significantly associated with an increasing trend of cfPWV, cdPWV and crPWV (P = 0.001, 0.049, and 0.038; respectively). In addition, we found significant interaction between hypertension status and NC level in relation to cfPWV, adjusted for age, sex, BMI, fasting glucose, lipids and heart rate(P for interaction = 0.034). The associations between NC and cfPWV were significant (P = 0.02) among those with hypertension, but not significant among those without hypertension. Conclusions Our data showed that high NC was associated with an increased risk of early stage atherosclerosis in Chinese adults, independent of other metabolic risk factors. Hypertension might modify the association between NC and cfPWV. PMID:25001365

  6. Early-Stage Capital Cost Estimation of Biorefinery Processes: A Comparative Study of Heuristic Techniques.

    PubMed

    Tsagkari, Mirela; Couturier, Jean-Luc; Kokossis, Antonis; Dubois, Jean-Luc

    2016-09-08

    Biorefineries offer a promising alternative to fossil-based processing industries and have undergone rapid development in recent years. Limited financial resources and stringent company budgets necessitate quick capital estimation of pioneering biorefinery projects at the early stages of their conception to screen process alternatives, decide on project viability, and allocate resources to the most promising cases. Biorefineries are capital-intensive projects that involve state-of-the-art technologies for which there is no prior experience or sufficient historical data. This work reviews existing rapid cost estimation practices, which can be used by researchers with no previous cost estimating experience. It also comprises a comparative study of six cost methods on three well-documented biorefinery processes to evaluate their accuracy and precision. The results illustrate discrepancies among the methods because their extrapolation on biorefinery data often violates inherent assumptions. This study recommends the most appropriate rapid cost methods and urges the development of an improved early-stage capital cost estimation tool suitable for biorefinery processes.

  7. Divergent natural selection promotes immigrant inviability at early and late stages of evolutionary divergence.

    PubMed

    Ingley, Spencer J; Johnson, Jerald B

    2016-03-01

    Natural selection's role in speciation has been of fundamental importance since Darwin first outlined his theory. Recently, work has focused on understanding how selection drives trait divergence, and subsequently reproductive isolation. "Immigrant inviability," a barrier that arises from selection against immigrants in their nonnative environment, appears to be of particular importance. Although immigrant inviability is likely ubiquitous, we know relatively little about how selection acts on traits to drive immigrant inviability, and how important immigrant inviability is at early-versus-late stages of divergence. We present a study evaluating the role of predation in the evolution of immigrant inviability in recently diverged population pairs and a well-established species pair of Brachyrhaphis fishes. We evaluate performance in a high-predation environment by assessing survival in the presence of a predator, and swimming endurance in a low-predation environment. We find strong signatures of local adaptation and immigrant inviability of roughly the same magnitude both early and late in divergence. We find remarkably conserved selection for burst-speed swimming (important in predator evasion), and selection for increased size in low-predation environments. Our results highlight the consistency with which selection acts during speciation, and suggest that similar factors might promote initial population differentiation and maintain differentiation at late stages of divergence.

  8. [GABA--the basic mediator of excitation in the early stages of hippocampal development].

    PubMed

    Khazipov, R N; Zefirov, A L; Ben-Ari, E

    1998-01-01

    GABA is the principal neurotransmitter of inhibition in the adult mammalian brain. However, at early stages of development, including embryonic period and first week of postnatal life, GABA plays the role of main neurotransmitter of excitation. The paradoxical excitatory effect of GABA is due to an inversed chloride gradient and therefore a depolarizing direction of GABA-A receptor mediated responses. In addition, another type of GABAergic inhibition mediated by postsynaptic GABA-B receptors is not functional at early stage of life. In the neonatal rat hippocampus, GABA, acting via GABA-A receptors, activates voltage gated sodium and calcium channels and potentiates the activity of NMDA receptors by reducing their voltage dependent Mg2+ block. The temporal window when GABA exerts excitatory actions coincides with a particular pattern of activity of hippocampal neuronal network that is characterized by periodical giant depolarizing potentials (GDPs) reminiscent of interictal-like epileptiform discharges. Recent studies have shown that GDPs result from the synchronous discharge of GABAergic interneurons and principal glutamatergic pyramidal cells and are mediated by the synergistic excitatory actions of GABA-A and glutamate receptors. GDPs provide synchronous intracellular Ca2+ oscillations and may therefore be implicated in hebbian modulation of developing synapses and activity-dependent formation of the hippocampal network.

  9. Ameliorative effect of the cinnamon oil from Cinnamomum zeylanicum upon early stage diabetic nephropathy.

    PubMed

    Mishra, Awanish; Bhatti, Rajbir; Singh, Amarjit; Singh Ishar, Mohan Paul

    2010-03-01

    The current study was designed to evaluate the ameliorative effect of the cinnamon oil upon early stage diabetic nephropathy owing to its antioxidant and antidiabetic effect. Cinnamon oil was extracted by hydro-distillation of the dried inner bark of Cinnamomum zeylanicum Blume. Further characterization of the extracted oil was carried out using IR, (1)H-NMR, and (13)C-NMR techniques. Early stage of diabetic nephropathy was induced by administration of alloxan (150 mg/kg, I. P.). Cinnamon oil was administered at varying doses (5, 10, 20 mg/kg; I. P.) while the level of fasting blood glucose, total cholesterol, high density lipoprotein, urea, thiobarbituric acid reactive substances, reduced glutathione, and catalase were determined. These parameters in cinnamon oil treated groups were compared with those of standard (glipizide; 10 mg/kg) and vehicle treated groups in order to investigate if cinnamon oil confers a significant protection against diabetic nephropathy. Histological studies of the kidney proved the protective effect of cinnamon oil by reducing the glomerular expansion, eradicating hyaline casts, and decreasing the tubular dilatations. Our results indicate that the volatile oil from cinnamon contains more than 98 % cinnamaldehyde and that it confers dose-dependent, significant protection against alloxan-induced renal damage, the maximum decrease in fasting blood glucose having been achieved at the dose of 20 mg/kg.

  10. Prenatal sonography in hydranencephaly: findings during the early stages of disease.

    PubMed

    Sepulveda, Waldo; Cortes-Yepes, Hernan; Wong, Amy E; Dezerega, Victor; Corral, Edgardo; Malinger, Gustavo

    2012-05-01

    The purpose of this report is to describe the prenatal sonographic findings in fetuses with hydranencephaly diagnosed during the early stages of disease. Four cases with characteristics of hydranencephaly were retrospectively identified from 2 Latin American fetal medicine referral centers. Information on maternal demographics, sonographic findings, antenatal courses, and pregnancy outcomes was retrieved from the ultrasound reports and medical records. Cases were diagnosed between 21 and 23 weeks' gestation. The sonographic findings were similar in all cases and included absent cerebral hemispheres, which were replaced by homogeneous echogenic material filling the supratentorial space, and preservation of the thalami, brain stem, and cerebellum. The head circumference measurement was within the normal range, but the transverse cerebellar diameter was below the fifth percentile in 3 of the 4 cases. A follow-up scan in 1 of these cases demonstrated the classic anechoic fluid-filled appearance of hydranencephaly 2 weeks after diagnosis. Confirmation of the diagnosis was available in 2 cases, by postmortem examination in 1 and by fetal magnetic resonance imaging in the other. No further investigations were performed in the 2 women who opted for termination of pregnancy. In conclusion, during the early stages of disease, hydranencephaly is characterized by the presence of a large intracranial saclike structure containing homogeneous echogenic material, representing blood and necrotic debris secondary to massive liquefaction of the developing cerebral hemispheres.

  11. Robotic Compartment-Based Radical Surgery in Early-Stage Cervical Cancer

    PubMed Central

    Toptas, Tayfun; Uysal, Aysel; Ureyen, Isin; Erol, Onur; Simsek, Tayup

    2016-01-01

    A radical hysterectomy with pelvic lymphadenectomy is the recommended treatment option in patients with early-stage cervical cancer. Although various classifications were developed in order to define the resection margins of this operation, no clear standardization could be achieved both in the nomenclature and in the extent of the surgery. Total mesometrial resection (TMMR) is a novel procedure which aims to remove all components of the compartment formed by Müllerian duct in which female reproductive organs develop. TMMR differs from the conventional radical hysterectomy techniques in that its surgical philosophy, terminology, and partly resection borders are different. In this paper, a TMMR with therapeutic pelvic lymphadenectomy operation that we performed for the first time with robot-assisted laparoscopic (robotic) approach in an early-stage cervical cancer patient was presented. This procedure has already been described in open surgery by Michael Höckel and translated to the robotic surgery by Rainer Kimmig. Our report is the second paper, to our knowledge, to present the initial experience regarding robotic TMMR in the English literature. PMID:27195167

  12. The Management of Early Stage and Metastatic Triple Negative Breast Cancer: A Review

    PubMed Central

    Anders, Carey K.; Zagar, Timothy M.; Carey, Lisa A.

    2013-01-01

    Triple negative breast cancer (TNBC) defined as lacking expression of the estrogen receptor, progesterone receptor and HER2, comprises approximately 15% of incident breast cancers and is over-represented among those with metastatic disease. It is increasingly clear that TNBC is heterogeneous and that there are several biologically distinct subtypes within TNBC, in particular the basal-like subtype but also the claudin-low, among others. While the incidence of BRCA mutations across all subsets of breast cancer is quite low (~5%), BRCA mutations are more common among those with TNBC (~20%) and may have therapeutic implications. The general principles guiding the use of chemotherapy and radiation therapy do not differ dramatically between early stage TNBC and non-TNBC. There is a trend, however, to treat TNBC at a lower stage with chemotherapy as this is the only way to systemically reduce recurrence risk. In the metastatic setting, while cytotoxic chemotherapy is the mainstay of treatment for advanced TNBC, there are many promising targeted therapies in development in both the preclinical and early phase clinical trial settings. While the treatment of TNBC remains a challenge, coordinated efforts between clinician/scientist partnerships providing a comprehensive understanding of TNBC genomic, proteomic and other biologic processes may result in individualized therapy for TNBC faster than other subtypes -- driven by both the heterogeneity we know exists within this clinical entity and the intense need for improved treatment. PMID:23915742

  13. Diagnosis of early-stage esophageal cancer by Raman spectroscopy and chemometric techniques.

    PubMed

    Ishigaki, Mika; Maeda, Yasuhiro; Taketani, Akinori; Andriana, Bibin B; Ishihara, Ryu; Wongravee, Kanet; Ozaki, Yukihiro; Sato, Hidetoshi

    2016-02-07

    Esophageal cancer is a disease with high mortality. In order to improve the 5 year survival rate after cancer treatment, it is important to develop a method for early detection of the cancer and for therapy support. There is increasing evidence that Raman spectroscopy, in combination with chemometric analysis, is a powerful technique for discriminating pre-cancerous and cancerous biochemical changes. In the present study, we used Raman spectroscopy to examine early-stage (stages 0 and I) esophageal cancer samples ex vivo. Comparison between the Raman spectra of cancerous and normal samples using a t-test showed decreased concentrations of glycogen, collagen, and tryptophan in cancerous tissue. Partial least squares regression (PLSR) analysis and self-organization maps (SOMs) discriminated the datasets of cancerous and normal samples into two groups, but there was a relatively large overlap between them. Linear discriminant analysis (LDA) based on Raman bands found in the t-test was able to predict the tissue types with 81.0% sensitivity and 94.0% specificity.

  14. Behavior of homologous chromosomes in early meiotic stages of human spermatocytes as revealed by FISH

    SciTech Connect

    Bar-Am, I.; Avivi, L.; Mukame, E.

    1994-09-01

    The process by which homologous chromosomes recognize each other at the beginning of meiosis, prior to synapsis, is poorly understood. To gain a better understanding as to when, where and how a given chromosome approaches its pairing partner, chromosome behavior at early stages of meiosis in human spermatocytes was studied. Using multi-color FISH with centromeric- and telomeric-specific probes, as well as with whole chromosome DNA libraries, it was clearly aligned. Rather, similarly to non-homologous chromosomes, they were well separated from each other. At the commencement of synapsis, during the process of homology search, homologues underwent a drastic conformational change, elongating into strands that approached each other by their telomeres. Just preceding the co-alignment of the homologous centromeres, telomeres changed their interphase random distribution and occupied a confined region of the nuclear periphery. Following synapsis, telomeres spread over the whole nuclear periphery. These dynamics in the telomeres distribution, which are unique to early stages of meiosis, are presumably related to the role that telomeres play in the process of homology search and the commencement of synapsis.

  15. Marital relationship quality in early-stage dementia: perspectives from people with dementia and their spouses.

    PubMed

    Clare, Linda; Nelis, Sharon M; Whitaker, Christopher J; Martyr, Anthony; Markova, Ivana S; Roth, Ilona; Woods, Robert T; Morris, Robin G

    2012-01-01

    Spouse caregivers of people with dementia (PwD) report relatively poor marital relationship quality (RQ), but few studies have obtained the perspective of the PwD, examined discrepancies between spouses, or considered changes in RQ over time. This study explored caregiver and PwD perceptions of RQ, identified associated factors, and examined changes over an 18-month period. Participants were 54 couples where one spouse had early-stage dementia and 54 were control couples. RQ was assessed with the Positive Affect Index. Measures of mood, stress, and quality of life (QoL) were also administered. The clinical couples were followed up after 9 and 18 months. Caregivers gave significantly lower RQ ratings than controls. PwD ratings did not differ significantly from those of caregivers or controls. Dyadic discrepancies were significantly greater in the clinical than in the control group. Caregiver ratings were associated with stress, whereas PwD ratings were associated with depression and QoL. Discrepancies were associated with caregiver stress and with PwD mood, QoL, and age. Caregiver ratings declined significantly over time; PwD ratings did not decline significantly, but showed different trends for men and women. It is important to consider RQ when considering how to support couples where one partner has early-stage dementia.

  16. Early life-stage toxicity test methods for gulf toadfish (Opsanus beta) and results using chlorpyrifos

    SciTech Connect

    Hansen, D.J.; Goodman, L.R.; Cripe, G.M.; Macauley, S.F.

    1986-02-01

    Gulf toadfish (Opsanus beta) were continuously exposed as embryos, sac fry, and juveniles to technical chlorpyrifos in two 49-day early life-stage toxicity tests. Survival was significantly (alpha = 0.05) reduced only in 150 micrograms/liter. However, toadfish exposed to chlorpyrifos concentrations from 3.7 to 150 micrograms/liter weighted significantly less than control fish: 9% lower in 3.7 micrograms/liter to 62% lower in 150 micrograms/liter. The 96-hr LC50 for juvenile fish was 520 micrograms/liter. Concentrations of chlorpyrifos in toadfish and bioconcentration factors increased with increasing exposure concentration, a condition not generally observed with other marine fishes and other test chemicals. These results demonstrated the procedures for, and the practicality of, early life-stage tests with this marine species. We recommend the use of the gulf toadfish for comparative toxicity testing and for evaluating the toxicity of substances in conjunction with ontogenetical, physiological, and histological investigations of this considerably studied genus. We do not recommend it for routine effects testing.

  17. Neuroprotection of Granulocyte Colony-Stimulating Factor for Early Stage Parkinson's Disease.

    PubMed

    Tsai, Sheng-Tzung; Chu, Sung-Chao; Liu, Shu-Hsin; Pang, Cheng-Yoong; Hou, Ting-Wen; Lin, Shinn-Zong; Chen, Shin-Yuan

    2017-03-13

    Parkinson's disease (PD) is a slowly progressive neurodegenerative disease. Both medical and surgical choices provide symptomatic treatment. Granulocyte colony-stimulating factor (G-CSF), a conventional treatment for hematological diseases, has demonstrated its effectiveness in acute and chronic neurological diseases through its anti-inflammatory and antiapoptosis mechanisms. Based on previous in vitro and in vivo studies, we administered a lower dose (3.3 μg/kg) G-CSF injection for 5 days and six courses for 1 year in early-stage PD patients as a phase I trial. The four PD patient's mean unified PD rating scale motor scores in medication off status remained stable from 23 before the first G-CSF injection to 22 during the 2-year follow-up. 3,4-Dihydroxy-6-18F-fluoro-l-phenylalanine (18F-DOPA) positron emission tomography (PET) studies also revealed an annual 3.5% decrease in radiotracer uptake over the caudate nucleus and 7% in the putamen, both slower than those of previous reports of PD. Adverse effects included transient muscular-skeletal pain, nausea, vomiting, and elevated liver enzymes. Based on this preliminary report, G-CSF seems to alleviate disease deterioration for early stage PD patients. The effectiveness of G-CSF was possibly due to its amelioration of progressive dopaminergic neuron degeneration.

  18. Sham Feeding with Chewing Gum in Early Stage of Acute Pancreatitis: A Randomized Clinical Trial

    PubMed Central

    Jiang, Zongxing; Liang, Hongyin; Huang, Zhu; Tang, Jiajia; Tang, Lijun

    2017-01-01

    Background The correlation between sham feeding and acute pancreatitis (AP) has only been examined in limited studies. We aimed to investigate the efficacy and safety of sham feeding in the early stage of AP. Material/Methods A randomized controlled clinical trial was performed. Equal groups of AP patients were recruited. Patients in the sham feeding group received chewing gum 4 times a day after admission. All patients in the trial received standard treatment consistent with the guidelines for AP. The primary outcomes were mortality, length of stay (LOS), and medical expenses. Secondary outcomes were the incidence of complications and other adverse events, return of gastrointestinal function, the details of enteral nutrition and intra-abdominal pressure. Results From May 2014 to December 2015, a total of 204 patients were recruited. The LOS and hospital costs in the sham feeding group were reduced, although mortality was equivalent between groups. The return of gastrointestinal function occurred earlier in the sham feeding group, with no complications related to gum chewing. Conclusions Sham feeding with chewing gum is safe and efficacious in the early stage of AP. PMID:28154369

  19. Thermodynamics, morphology, and kinetics of early- stage self-assembly of pi-conjugated oligopeptides

    NASA Astrophysics Data System (ADS)

    Thurston, Bryce; Tovar, John; Ferguson, Andrew

    Synthetic oligopeptides containing π-conjugated cores self-assemble novel materials with attractive electronic and photophysical properties. All-atom, explicit solvent molecular dynamics simulations of Asp-Phe-Ala-Gly-OPV3-Gly-Ala-Phe-Asp peptides were used to parameterize an implicit solvent model to simulate self-assembly. At low-pH conditions, peptides assemble into β-sheet-like stacks with strongly favorable monomer association free energies of ΔF ~ - 25kB T . Aggregation at high-pH produces disordered aggregates destabilized by Coulombic repulsion between negatively charged Asp termini. We model simulations of hundereds of monomers as a continuous-time Markov process. We infer transition rates between different aggregate sizes and microsecond relaxation times for early-stage assembly. Our data suggests a hierarchical model of assembly in which peptides coalesce into small clusters over tens of nanoseconds followed by structural ripening and diffusion limited aggregation on longer time scales. This work provides new molecular-level understanding of early-stage assembly, and a means to study the impact of peptide chemistry upon the thermodynamics, assembly kinetics, and morphology of the supramolecular aggregates. Supported by U.S. Department of Energy, Office of Science, Basic Energy Sciences, Award DE-SC0004857. Molecular simulations partially conducted on University of Illinois Computational Science and Engineering Program parallel computing resources.

  20. Brain Event-Related Potentials: Diagnosing Early-Stage Alzheimer’s Disease

    PubMed Central

    Chapman, Robert M.; Nowlis, Geoffrey H.; McCrary, John W.; Chapman, John A.; Sandoval, Tiffany C.; Guillily, Maria D.; Gardner, Margaret N.; Reilly, Lindsey A.

    2009-01-01

    A pattern of components from brain Event-Related Potentials (ERP) (cognitive non-invasive electrical brain measures) performed well in separating early-stage Alzheimer’s disease (AD) subjects from normal-aging control subjects and shows promise for developing a clinical diagnostic for Probable AD. A Number-Letter task elicited brain activity related to cognitive processes. In response to the task stimuli, brain activity was recorded as ERPs, whose components were measured by Principal Components Analysis (PCA). The ERP component scores to relevant and irrelevant stimuli were used in Discriminant Analyses to develop functions that successfully classified individuals as belonging to an early-stage Alzheimer’s disease group or a like-aged Control group, with probabilities of an individual belonging to each group. Applying the discriminant function to the developmental half of the data showed 92% of the subjects were correctly classified into either the AD group or the Control group with a sensitivity of 1.00. The two crossvalidation results were good with sensitivities of 0.83 and classification accuracies of 0.75–0.79. P3 and CNV components, as well as other, earlier ERP components, e.g. C145 and the memory “Storage” component, were useful in the discriminant functions. PMID:16430992

  1. A decision-analytic model for early stage breast cancer: lumpectomy vs mastectomy.

    PubMed

    Büyükdamgaci-Alogan, G; Elele, T; Hayran, M; Erman, M; Kiliçkap, S

    2008-01-01

    The purpose was to construct a decision model that incorporated patient preferences over differing health state prospects and to analyze the decision context of early stage breast cancer patients in relation to two main surgical treatment options. A Markov chain was constructed to project the clinical history of breast carcinoma following surgery. A Multi Attribute Utility Model was developed for outcome evaluation. Transition probabilities were obtained by using subjective probability assessment. This study was performed on the sample population of female university students and utilities were elicited from these healthy volunteers. The results were validated by using Standard Gamble technique. Finally, Monte Carlo Simulation was utilized in Treeage-Pro 2006-Suit software program in order to calculate expected utility generated by each treatment option. The results showed that, if the subject had mastectomy, mean value for the quality adjusted life years gained was 6.42; on the other hand, if the preference was lumpectomy, it was 7.00 out of a possible 10 years. Sensitivity analysis on transition probabilities to local recurrence and salvaged states was performed and two threshold values were observed. Additionally, sensitivity analysis on utilities showed that the model was more sensitive to no evidence of disease state; however, was not sensitive to utilities of local recurrence and salvaged states. The decision model was developed with reasonable success for early stage breast cancer patients, and tested by using general public data. The results obtained from these data showed that lumpectomy was more favourable for these participants.

  2. Effects of marine toxins on the reproduction and early stages development of aquatic organisms.

    PubMed

    Vasconcelos, Vítor; Azevedo, Joana; Silva, Marisa; Ramos, Vítor

    2010-01-19

    Marine organisms, and specially phytoplankton species, are able to produce a diverse array of toxic compounds that are not yet fully understood in terms of their main targets and biological function. Toxins such as saxitoxins, tetrodotoxin, palytoxin, nodularin, okadaic acid, domoic acid, may be produced in large amounts by dinoflagellates, cyanobacteria, bacteria and diatoms and accumulate in vectors that transfer the toxin along food chains. These may affect top predator organisms, including human populations, leading in some cases to death. Nevertheless, these toxins may also affect the reproduction of aquatic organisms that may be in contact with the toxins, either by decreasing the amount or quality of gametes or by affecting embryonic development. Adults of some species may be insensitive to toxins but early stages are more prone to intoxication because they lack effective enzymatic systems to detoxify the toxins and are more exposed to the toxins due to a higher metabolic growth rate. In this paper we review the current knowledge on the effects of some of the most common marine toxins on the reproduction and development of early stages of some organisms.

  3. Properties of large scale plasma flow during the early stage of the plasmaspheric refilling

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Craven, P.; Torr, D. G.; Richards, P. G.

    1990-01-01

    The objective is to better characterize the macroscopic properties of the interhemisphere plasma flow by solving a more complete set of hydrodynamic equations than that solved previously. Specifically, the ion continuity, momentum and energy equations were solved for the plasma flow along the closed magnetic field lines. During the initial stage of the supersonic outflow in the equatorial region, the ions cool substantially. Using the hydrodynamic model for the large-scale plasma flow, the dynamics of shocks was examined which form in the geomagnetic flux tubes during the early stages of refilling. These shocks are more like those forming in neutral gases than the electrostatic shocks driven by microinstabilities involving ion-ion interaction. Therefore, the shocks seen in the hydrodynamic model are termed as hydrodynamic shocks. Such shocks are generally unsteady and therefore the usual shock jump conditions given by Rankine-Hugoniot relations are not strictly applicable to them. The density, flow velocity and temperature structures associated with the shocks are examined for both asymmetrical and symmetrical flows. In the asymmetrical flow the outflow from one of two conjugate ionospheres is dominant. On the other hand, in the symmetrical case outflows from the two ionospheric sources are identical. Both cases are treated by a two-stream model. In the late type of flow, the early-time refilling shows a relaxation type of oscillation, which is driven by the large-scale interactions between the two identical streams. After this early stage, the resulting temperature structure shows some interesting features. In the equatorial region the streams are isothermal, but in the off-equatorial regions the streams have quite different temperatures, and also densities and flow velocities. The dense and slow stream is found to be warmer than the low-density fast stream. In the late stage of refilling, the temperature is found to steadily increase from the conjugate

  4. Targeting of Cancer Stem Cells and Their Microenvironment in Early-Stage MutantK-ras Lung Cancer

    DTIC Science & Technology

    2015-10-01

    would expect the results that we have seen. However, according to the cancer stem cell theory (5), transient amplifying cells have limited capacity...1 AWARD NUMBER: W81XWH-14-1-0338 TITLE: Targeting of Cancer Stem Cells and Their Microenvironment in Early-Stage Mutant K-ras Lung Cancer...COVERED 15 Sep 2014 - 14 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Targeting of Cancer Stem Cells and Their Microenvironment in Early-Stage

  5. Orthostatic hypotension is associated with decreased cerebrospinal fluid levels of chromogranin A in early stage of Parkinson disease.

    PubMed

    Kaiserova, Michaela; Prikrylova Vranova, Hana; Galuszka, Jan; Stejskal, David; Mensikova, Katerina; Zapletalova, Jana; Mares, Jan; Kanovsky, Petr

    2015-10-01

    An association between the CSF chromogranin A (CgA) and orthostatic blood pressure changes was investigated in 20 patients in the early stage of Parkinson disease (PD). There was a positive correlation between the CSF CgA and diastolic blood pressure change, when CSF CgA levels were lower in patients with orthostatic hypotension (OH). Decreased CSF CgA may be useful in predicting OH in the early stage of PD.

  6. Trefoil Factor 1 Excretion Is Increased in Early Stages of Chronic Kidney Disease

    PubMed Central

    Lebherz-Eichinger, Diana; Tudor, Bianca; Ankersmit, Hendrik J.; Reiter, Thomas; Haas, Martin; Roth-Walter, Franziska; Krenn, Claus G.; Roth, Georg A.

    2015-01-01

    Chronic kidney disease (CKD) is associated with high morbidity and mortality. In many patients CKD is diagnosed late during disease progression. Therefore, the implementation of potential biomarkers may facilitate the early identification of individuals at risk. Trefoil factor family (TFF) peptides promote restitution processes of mucous epithelia and are abundant in the urinary tract. We therefore sought to investigate the TFF peptide levels in patients suffering from CKD and their potential as biomarkers for CKD. We analysed TFF1 and TFF3 in serum and urine of 115 patients with CKD stages 1–5 without dialysis by ELISA. 20 healthy volunteers served as controls. Our results showed, that urinary TFF1 levels were significantly increased with the onset of CKD in stages 1–4 as compared to controls and declined during disease progression (p = 0.003, < 0.001, 0.005, and 0.007. median concentrations: 3.5 pg/mL in controls vs 165.2, 61.1, 17.2, and 15.8 pg/mL in CKD 1–4). TFF1 and TFF3 serum levels were significantly elevated in stages 3–5 as compared to controls (TFF1: p < 0.01; median concentrations: 12.1, 39.7, and 34.5 pg/mL in CKD 3–5. TFF3: p < 0.001; median concentrations: 7.1 ng/mL in controls vs 26.1, 52.8, and 78.8 ng/mL in CKD 3–5). TFF3 excretion was increased in stages 4 and 5 (p < 0.001; median urinary levels: 65.2 ng/mL in controls vs 231.5 and 382.6 ng/mL in CKD 4/5; fractional TFF3 excretion: 6.4 in controls vs 19.6 and 44.1 in CKD 4/5). ROC curve analyses showed, that monitoring TFF peptide levels can predict various CKD stages (AUC urinary/serum TFF > 0.8). In conclusion our results show increased levels of TFF1 and TFF3 in CKD patients with a pronounced elevation of urinary TFF1 in lower CKD stages. Furthermore, TFF1 and TFF3 seems to be differently regulated and show potential to predict various CKD stages, as shown by ROC curve analysis. PMID:26390128

  7. Moss harvest truncates the successional development of epiphytic bryophytes in the Pacific Northwest.

    PubMed

    Peck, Jerilynn E; Frelich, Lee E

    2008-01-01

    We evaluated the impact of commercial moss harvest on the development of an understory epiphyte community in the Pacific Northwest by characterizing natural development stages using data from both a long-term regrowth study and demographic sampling. First, experimentally stripped 1 m long cylindrats on 46 shrub stems in the Oregon Coast Range were monitored for species composition and abundance annually during the first five years of recovery and again in year 10. Second, a pathway of community development was inferred by examining the relative species composition and abundance of epiphytic species present in moss mats in a four-stage chronosequence. We (1) characterized the change in richness and composition from year 1 through 10 of regrowth following experimental disturbance, (2) quantified the proportion of approximately 1-, 10-, 25-, and 50-year-old moss mats of commercially harvestable species that were monodominant, diverse, and late successional, and (3) contrasted these proportions with estimates from a compositional transition matrix derived from long-term monitoring. Roughly half of the observed moss mats demonstrated neutral dynamics and were composed of a mixture of readily dispersed acrocarps and pleurocarps. The remaining half exhibited positive dynamics and were dominated by aggressively growing pleurocarpous species such as Isothecium myosuroides. Following structural developmental pathways well established for vascular plants, moss mats shift with time from high diversity and evenness in the initial colonization and extended establishment phases to increasing Isothecium dominance during a presumed competitive-exclusion phase. Old mats exist in alternate states of either Isothecium dominance or mixed composition, either of which may have late-successional species. Patchy historic commercial moss harvest likely facilitated high diversity by increasing the simultaneous occurrence of all moss mat age classes, while modern strip harvesting methods are

  8. Application of Carnegie stages of development to unify human and baboon ultrasound findings early in pregnancy.

    PubMed

    Santolaya-Forgas, Joaquin; De Leon-Luis, Juan; Friel, Lara A; Wolf, Roman

    2007-09-01

    The objective of this study was to determine if very early ultrasonographic measurements obtained from human and baboon are comparable. For this purpose, the gestational, amniotic and yolk sacs, embryonic crown rump length (CRL) and heart rate were measured ultrasonographically between 35 and 47 days from the mean day of a three-day mating period in baboons (n=18) and between 42 to 58 days from fertilization as calculated from the CRL measurements in human pregnancies (n=82). Ultrasonographic measurements from both species were then plotted in the same graph using Carnegie stages of embryonic development as the independent variable to allow for visual comparisons. Mean gestational age at ultrasonographic studies was significantly different for humans and baboons (50.4 vs. 41 days, respectively; p>0.01). Significant correlations (p>0.01) were noted between ultrasonographic measurements and Carnegie stages of development in both humans and baboons. Only the gestational and the yolk sacs were significantly smaller in baboons than in humans (p>0.05). The findings that embryonic CRL, extra-embryonic space and heart rate are very similar between the 17th and 23rd Carnegie developmental stages make the baboon a promising surrogate of human pregnancy for investigations using celocentesis.

  9. Identification of genes involved in rice seed priming in the early imbibition stage.

    PubMed

    Cheng, J; Wang, L; Zeng, P; He, Y; Zhou, R; Zhang, H; Wang, Z

    2017-01-01

    Phase II of seed imbibition is a critical process during seed priming. To identify genes involved in rice seed priming, the altered proteins between the dry and imbibed (24 h) seeds were compared using a two-dimensional gel electrophoresis system in this study. Ten significantly changed proteins (fold change ≥ twofold; P < 0.01) were successfully identified, which could be categorised as carbohydrate and protein biosynthesis and metabolism-related, signalling-related, storage and stress-related proteins. A meta-analysis indicated that the highest expression of the identified genes was at the milk and dough stages and in the endosperm tissue. Quantitative real-time PCR analysis showed that there was significant variation in gene expression (except FAD-dependent oxidoreductase) in embryos during seed priming (0-48 h). The expression of genes associated with stress appeared at the early imbibition stage, while those associated with carbohydrate metabolism, protein synthesis and signalling increased at the late imbibition stage. Three identified proteins (glucose-1-phosphate adenylyltransferase large subunit, aminotransferase and prolamin precursor) had similar transcript and protein expression patterns in embryos. Based on phenotype and gene expression, the optimal stop time for seed priming is 24 h, when these three genes have relatively low expression, followed by significant induction during imbibition in embryos. These three genes are ideal candidate biomarkers for rice seed priming.

  10. Early-Stage Young Breast Cancer Patients: Impact of Local Treatment on Survival

    SciTech Connect

    Bantema-Joppe, Enja J.; Munck, Linda de; Willemse, Pax H.B.; Langendijk, Johannes A.; Siesling, Sabine; Maduro, John H.

    2011-11-15

    Purpose: In young women, breast-conserving therapy (BCT), i.e., lumpectomy followed by radiotherapy, has been associated with an increased risk of local recurrence. Still, there is insufficient evidence that BCT impairs survival. The aim of our study was to compare the effect of BCT with mastectomy on overall survival (OS) in young women with early-stage breast cancer. Methods and Materials: From two Dutch regional population-based cancer registries (covering 6.2 million inhabitants) 1,453 women <40 years with pathologically T1N0-1M0 breast cancer were selected. Cox regression survival analysis was used to study the effect of local treatment (BCT vs. mastectomy) stratified for nodal stage on survival and corrected for tumor size, age, period of diagnosis, and use of adjuvant systemic therapy. Results: With a median follow-up of 9.6 years, 10-year OS was 83% after BCT and 78% after mastectomy, respectively (unadjusted hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.09-1.72). In N0-patients, 10-year OS was 84% after BCT and 81% after mastectomy and local treatment was not associated with differences in OS (HR 1.19; 95% CI, 0.89-1.58; p = 0.25). Within the N1-patient group, OS was better after BCT compared with mastectomy, 79% vs. 71% at 10 years (HR 1.91; 95% CI, 1.28-2.84; p = 0.001) and in patients treated with adjuvant hormonal therapy (HR 0.34; 95% CI, 0.18-0.66; p = 0.001). Conclusions: In this large population-based cohort of early-stage young breast cancer patients, 10-year OS was not impaired after BCT compared with mastectomy. Patients with 1 to 3 positive lymph nodes had better prognosis after BCT than after mastectomy.

  11. Developmental and physiological challenges of octopus (Octopus vulgaris) early life stages under ocean warming.

    PubMed

    Repolho, Tiago; Baptista, Miguel; Pimentel, Marta S; Dionísio, Gisela; Trübenbach, Katja; Lopes, Vanessa M; Lopes, Ana Rita; Calado, Ricardo; Diniz, Mário; Rosa, Rui

    2014-01-01

    The ability to understand and predict the effects of ocean warming (under realistic scenarios) on marine biota is of paramount importance, especially at the most vulnerable early life stages. Here we investigated the impact of predicted environmental warming (+3 °C) on the development, metabolism, heat shock response and antioxidant defense mechanisms of the early stages of the common octopus, Octopus vulgaris. As expected, warming shortened embryonic developmental time by 13 days, from 38 days at 18 °C to 25 days at 21 °C. Concomitantly, survival decreased significantly (~29.9 %). Size at hatching varied inversely with temperature, and the percentage of smaller premature paralarvae increased drastically, from 0 % at 18 °C to 17.8 % at 21 °C. The metabolic costs of the transition from an encapsulated embryo to a free planktonic form increased significantly with warming, and HSP70 concentrations and glutathione S-transferase activity levels were significantly magnified from late embryonic to paralarval stages. Yet, despite the presence of effective antioxidant defense mechanisms, ocean warming led to an augmentation of malondialdehyde levels (an indicative of enhanced ROS action), a process considered to be one of the most frequent cellular injury mechanisms. Thus, the present study provides clues about how the magnitude and rate of ocean warming will challenge the buffering capacities of octopus embryos and hatchlings' physiology. The prediction and understanding of the biochemical and physiological responses to warmer temperatures (under realistic scenarios) is crucial for the management of highly commercial and ecologically important species, such as O. vulgaris.

  12. Analysis of cerebro-spinal fluid protein composition in early developmental stages in chick embryos.

    PubMed

    Gato, A; Martín, P; Alonso, M I; Martín, C; Pulgar, M A; Moro, J A

    2004-04-01

    Foetal cerebro-spinal fluid (CSF) has a very high protein concentration when compared to adult CSF, and in many species five major protein fractions have been described. However, the protein concentration and composition in CSF during early developmental stages remains largely unknown. Our results show that in the earliest stages (18 to 30 H.H.) of chick development there is a progressive increase in CSF protein concentration until foetal values are attained. In addition, by performing electrophoretic separation and high-sensitivity silver staining, we were able to identify a total of 21 different protein fractions in the chick embryo CSF. In accordance with the developmental pattern of their concentration, these can be classified as follows: A: high-concentration fractions which corresponded with the ones described in foetal CSF by other authors; B: low-concentration fractions which remained stable throughout the period studied; C: low-concentration fractions which show changes during this period. The evolution and molecular weight of the latter group suggest the possibility of an important biological role. Our data demonstrate that all the CSF protein fractions are present in embryonic serum; this could mean that the specific transport mechanisms in neuroepithelial cells described in the foetal period evolve in very early stages of development. In conclusion, this paper offers an accurate study of the protein composition of chick embryonic CSF, which will help the understanding of the influences on neuroepithelial stem cells during development and, as a result, the appropriate conditions for the in vitro study of embryonic/foetal nervous tissue cells.

  13. Tangential Radiotherapy Without Axillary Surgery in Early-Stage Breast Cancer: Results of a Prospective Trial

    SciTech Connect

    Wong, Julia S.; Winer, Eric P.

    2008-11-01

    Purpose: To determine the risk of regional-nodal recurrence in patients with early-stage, invasive breast cancer, with clinically negative axillary nodes, who were treated with breast-conserving surgery, 'high tangential' breast radiotherapy, and hormonal therapy, without axillary surgery or the use of a separate nodal radiation field. Methods and Materials: Between September 1998 and November 2003, 74 patients who were {>=}55 years of age with Stage I-II clinically node-negative, hormone-receptor-positive breast cancer underwent tumor excision to negative margins without axillary surgery as a part of a multi-institutional prospective study. Postoperatively, all underwent high-tangential, whole-breast radiotherapy with a boost to the tumor bed, followed by 5 years of hormonal therapy. Results: For the 74 patients enrolled, the median age was 74.5 years, and the median pathologic tumor size was 1.2 cm. Lymphatic vessel invasion was present in 5 patients (7%). At a median follow-up of 52 months, no regional-nodal failures or ipsilateral breast recurrences had been identified (95% confidence interval, 0-4%). Eight patients died, one of metastatic disease and seven of other causes. Conclusion: In this select group of mainly older patients with early-stage hormone-responsive breast cancer and clinically negative axillary nodes, treatment with high-tangential breast radiotherapy and hormonal therapy, without axillary surgery, yielded a low regional recurrence rate. Such patients might be spared more extensive axillary treatment (axillary surgery, including sentinel node biopsy, or a separate nodal radiation field), with its associated time, expense, and morbidity.

  14. A Candida albicans early stage biofilm detachment event in rich medium

    PubMed Central

    2009-01-01

    Background Dispersal from Candida albicans biofilms that colonize catheters is implicated as a primary factor in the link between contaminated catheters and life threatening blood stream infections (BSI). Appropriate in vitro C. albicans biofilm models are needed to probe factors that induce detachment events. Results Using a flow through system to culture C. albicans biofilms we characterized a detachment process which culminates in dissociation of an entire early stage biofilm from a silicone elastomer surface. We analyzed the transcriptome response at time points that bracketed an abrupt transition in which a strong adhesive association with the surface is weakened in the initial stages of the process, and also compared batch and biofilm cultures at relevant time points. K means analysis of the time course array data revealed categories of genes with similar patterns of expression that were associated with adhesion, biofilm formation and glycoprotein biosynthesis. Compared to batch cultures the biofilm showed a pattern of expression of metabolic genes that was similar to the C. albicans response to hypoxia. However, the loss of strong adhesion was not obviously influenced by either the availability of oxygen in the medium or at the silicone elastomer surface. The detachment phenotype of mutant strains in which selected genes were either deleted or overexpressed was characterized. The microarray data indicated that changes associated with the detachment process were complex and, consistent with this assessment, we were unable to demonstrate that transcriptional regulation of any single gene was essential for loss of the strong adhesive association. Conclusion The massive dispersal of the early stage biofilm from a biomaterial surface that we observed is not orchestrated at the level of transcriptional regulation in an obvious manner, or is only regulated at this level by a small subpopulation of cells that mediate adhesion to the surface. PMID:19187560

  15. The incidence of bone metastasis after early-stage breast cancer in Canada.

    PubMed

    Liede, Alexander; Jerzak, Katarzyna J; Hernandez, Rohini K; Wade, Sally W; Sun, Ping; Narod, Steven A

    2016-04-01

    Current information on the incidence and prevalence of bone metastases in women with breast cancer is scarce. This study examined the occurrence and predictors of bone metastases, as well as post-metastasis survival in a prospective cohort of Canadian women with breast cancer. We included women treated for early-stage (stage I, II, or III) breast cancer at the Henrietta Banting Breast Centre (HBBC) in Toronto, Canada between 1987 and 2000. Data were abstracted from medical records and pathology reports in the HBBC database; follow-up extended to end of data availability or August 31, 2015. Actuarial survival analyses provided cumulative incidence of bone metastases at 5, 10, and 15 years after breast cancer diagnosis. Kaplan-Meier curves describe breast cancer mortality. Regression models assessed patient, tumor, and treatment characteristics as predictors of bone metastases with all-cause mortality as a competing risk. Among 2097 women studied, the 5-, 10-, and 15-year probability of bone metastasis was 6.5, 10.3, and 11.3 % for the first recurrence, and 8.4, 12.5, and 13.6 % for any bone recurrence. At median follow-up (12.5 years), 13.2 % of patients had bone metastases. Median survival was 1.6 years following bone metastasis, and shorter if both bone and visceral metastases occurred. Advanced age and adjuvant treatment with tamoxifen were protective against bone metastasis. In this representative cohort of women diagnosed with early-stage breast cancer in Ontario, Canada, with long follow-up, the incidence of bone metastases was consistent with longitudinal studies from the United Kingdom, Denmark, and the US.

  16. Identification of morphological markers of sarcopenia at early stage of aging in skeletal muscle of mice.

    PubMed

    Sayed, Ramy K A; de Leonardis, Erika Chacin; Guerrero-Martínez, José A; Rahim, Ibtissem; Mokhtar, Doaa M; Saleh, Abdelmohaimen M; Abdalla, Kamal E H; Pozo, María J; Escames, Germaine; López, Luis C; Acuña-Castroviejo, Darío

    2016-10-01

    The gastrocnemius muscle (GM) of young (3months) and aged (12months) female wild-type C57/BL6 mice was examined by light and electron microscopy, looking for the presence of structural changes at early stage of the aging process. Morphometrical parameters including body and gastrocnemius weights, number and type of muscle fibers, cross section area (CSA), perimeter, and Feret's diameter of single muscle fiber, were measured. Moreover, lengths of the sarcomere, A-band, I-band, H-zone, and number and CSA of intermyofibrillar mitochondria (IFM), were also determined. The results provide evidence that 12month-old mice had significant changes on skeletal muscle structure, beginning with the reduction of gastrocnemius weight to body weight ratio, compatible with an early loss of skeletal muscle function and strength. Moreover, light microscopy revealed increased muscle fibers size, with a significant increase on their CSA, perimeter, and diameter of both type I and type II muscle fibers, and a reduction in the percentage of muscle area occupied by type II fibers. Enhanced connective tissue infiltrations, and the presence of centrally nucleated muscle fibers, were also found in aged mice. These changes may underlie an attempt to compensate the loss of muscle mass and muscle fibers number. Furthermore, electron microscopy discovered a significant age-dependent increase in the length of sarcomeres, I and H bands, and reduction on the overlapped actin/myosin length, supporting contractile force loss with age. Electron microscopy also showed an increased number and CSA of IFM with age, which may reveal more endurance at 12months of age. Together, mice at early stage of aging already show significant changes in gastrocnemius muscle morphology and ultrastructure that are suggestive of the onset of sarcopenia.

  17. Development of Valpha4+ NK T cells in the early stages of embryogenesis.

    PubMed Central

    Makino, Y; Kanno, R; Koseki, H; Taniguchi, M

    1996-01-01

    The majority of T lymphocytes start to develop at around day 15 of gestation (d15)-d17 in the thymus and comprise the peripheral repertoire characterized by the expression of polymorphic T-cell antigen receptors (TCRs). Contrary to these conventional T cells, a subset of T cells, called natural killer (NK) T cells (most of them expressing an invariant TCR encoded by the Valpha14Jalpha281 gene with a 1-nt N-region), preferentially differentiates extrathymically and dominates the peripheral T-cell population at a high frequency (5% in splenic T cells and 40% in bone marrow T cells). Here, we investigated the development of NK T cells and found that the invariant Valpha14+ TCR transcripts and the circular DNA created by Valpha14 and Jalpha281 gene rearrangements can be detected in the embryo body at d9.5 of gestation and in the yolk sac and the fetal liver at d11.5-d13.5 of gestation, but not in the thymus, whereas T cells with Valpha1+ TCR expression, a major population in the thymus, were not observed at these early stages of gestation. Fluorescence-activated cell sorter analysis also demonstrated that there exist CD3+ alpha beta+ T cells, almost all of which are Valpha14/Vbeta8+ NK+ T cells, during early embryogenesis. To our knowledge, this demonstrates for the first time that a T lymphocyte subset develops in extrathymic tissues during the early stages of embryogenesis. Images Fig. 1 Fig. 4 PMID:8692847

  18. 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.

  19. Annual surveillance mammography after early-stage breast cancer and breast cancer mortality

    PubMed Central

    Paszat, L.F.; Sutradhar, R.; Gu, S.; Rakovitch, E.

    2016-01-01

    Background After treatment for early-stage breast cancer (bca), annual surveillance mammography (asm) is recommended based on the assumption that early detection of an invasive ipsilateral breast tumour recurrence or subsequent invasive contralateral primary bca reduces bca mortality. Methods We studied women with unilateral early-stage bca treated by breast-conserving surgery from 1994 to 1997 who subsequently developed an ipsilateral recurrence or contralateral primary more than 24 months after initial diagnosis, without prior regional or distant metastases. Annual surveillance mammography was defined as 2 episodes of bilateral mammography 11–18 months apart during the 2 years preceding the ipsilateral recurrence or contralateral primary. The association between asm and bca death was evaluated using a Cox proportional hazards model. Results We identified 669 women who experienced invasive ipsilateral recurrence (n = 455) or a contralateral primary (n = 214) at a median interval of 53 months [interquartile range (iqr): 37–72 months] after initial diagnosis, 64.7% of whom had received asm during the preceding 2 years. The median interval between the 2 bilateral mammograms was 12.3 months (iqr: 11.9–13.0 months), and the median interval between the 2nd mammogram and histopathologic confirmation of ipsilateral recurrence or contralateral primary was 1.5 months (iqr: 0.8–3.9 months). Median followup after ipsilateral recurrence or contralateral primary was 7.76 years (iqr: 3.68–9.81 years). The adjusted hazard ratio for bca death associated with asm was 0.86 (95% confidence limits: 0.63, 1.16). Conclusions Annual surveillance mammography was associated with a modestly lowered hazard ratio for bca death. PMID:28050142

  20. [Prenatal cerebrovascular accidents diagnosed in the early infant stage: a series of 10 patients].

    PubMed

    Pina-Jover, María; Martinez-Del Villar, María; Lillo-Laguna, Lucía; Jadraque-Rodriguez, Rocío; Martinez-Pastor, Pedro; Jover-Cerda, Jenaro; Gomez-Gosalvez, Francisco

    2013-07-01

    INTRODUCTION. A foetal or prenatal cerebrovascular accident (CVA) is defined as an ischaemic, thrombotic or arterial or venous haemorrhagic event that occurs between the 14th week of gestation and the onset of labour. PATIENTS AND METHODS. We report a retrospective study of a series of 10 patients suffering from a, presumably foetal, stroke that went unnoticed during the pregnancy and was diagnosed in the early infant stage. The symptoms and the age at which they were identified are highlighted. RESULTS. None of the 10 patients studied presented any relevant events in the mothers' medical history, but there were four threats of a preterm birth that were solved using the usual means and without the occurrence of any alterations that later affected the foetus. The studies that led to the diagnosis were carried out between the sixth and ninth months of life, and the reason for visiting was reported by the family as being a lower degree of mobility on one side of the body with respect to the other. Two patients presented thrombophilia. With a mean follow-up time of six years, all the patients have an associated infantile cerebral palsy, a third of them have epilepsy and 75% have learning difficulties or intellectual disability. CONCLUSIONS. When CVA are not detected in the prenatal period, it is important in primary care to look for and detect the warning signs of the psychomotor development of the infant at an early stage in order to begin a study of the case and to undertake rehabilitation as early as possible.

  1. Adoption of Intensity Modulated Radiation Therapy For Early-Stage Breast Cancer From 2004 Through 2011

    SciTech Connect

    Wang, Elyn H.; Mougalian, Sarah S.; Soulos, Pamela R.; Smith, Benjamin D.; Haffty, Bruce G.; Gross, Cary P.; Yu, James B.

    2015-02-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a newer method of radiation therapy (RT) that has been increasingly adopted as an adjuvant treatment after breast-conserving surgery (BCS). IMRT may result in improved cosmesis compared to standard RT, although at greater expense. To investigate the adoption of IMRT, we examined trends and factors associated with IMRT in women under the age of 65 with early stage breast cancer. Methods and Materials: We performed a retrospective study of early stage breast cancer patients treated with BCS followed by whole-breast irradiation (WBI) who were ≤65 years old in the National Cancer Data Base from 2004 to 2011. We used logistic regression to identify factors associated with receipt of IMRT (vs standard RT). Results: We identified 11,089 women with early breast cancer (9.6%) who were treated with IMRT and 104,448 (90.4%) who were treated with standard RT, after BCS. The proportion of WBI patients receiving IMRT increased yearly from 2004 to 2009, with 5.3% of WBI patients receiving IMRT in 2004 and 11.6% receiving IMRT in 2009. Further use of IMRT declined afterward, with the proportion remaining steady at 11.0% and 10.7% in 2010 and 2011, respectively. Patients treated in nonacademic community centers were more likely to receive IMRT (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.30-1.43 for nonacademic vs academic center). Compared to privately insured patients, the uninsured patients (OR, 0.81; 95% CI, 0.70-0.95) and those with Medicaid insurance (OR, 0.87; 95% CI, 0.79-0.95) were less likely to receive IMRT. Conclusions: The use of IMRT rose from 2004 to 2009 and then stabilized. Important nonclinical factors associated with IMRT use included facility type and insurance status.

  2. Oxidative reactions during early stages of beer brewing studied by electron spin resonance and spin trapping.

    PubMed

    Frederiksen, Anne M; Festersen, Rikke M; Andersen, Mogens L

    2008-09-24

    An electron spin resonance (ESR)-based method was used for evaluating the levels of radical formation during mashing and in sweet wort. The method included the addition of 5% (v/v) ethanol together with the spin trap alpha-4-pyridyl(1-oxide)- N- tert-butylnitrone (POBN) to wort, followed by monitoring the rate of formation of POBN spin adducts during aerobic heating of the wort. The presence of ethanol makes the spin trapping method more selective and sensitive for the detection of highly reactive radicals such as hydroxyl and alkoxyl radicals. Samples of wort that were collected during the early stages of the mashing process gave higher rates of spin adduct formation than wort samples collected during the later stages. The lower oxidative stability of the early wort samples was confirmed by measuring the rate of oxygen consumption during heating of the wort. The addition of Fe(II) to the wort samples increased the rate of spin adduct formation, whereas the addition of Fe(II) during the mashing had no effect on the oxidative stability of the wort samples. Analysis of the iron content in the sweet wort samples demonstrated that iron added during the mashing had no effect on the iron level in the wort. The moderate temperatures during the early steps of mashing allow the endogenous malt enzymes to be active. The potential antioxidative effects of different redox-active enzymes during mashing were tested by measuring the rate of spin adduct formation in samples of wort. Surprisingly, a high catalase dosage caused a significant, 20% reduction of the initial rate of radical formation, whereas superoxide dismutase had no effect on the oxidation rates. This suggests that hydrogen peroxide and superoxide are not the only intermediates that play a role in the oxidative reactions occurring during aerobic oxidation of sweet wort.

  3. Potential diagnostic role of diffusion tensor imaging in early-stage osteonecrosis of the femoral head

    PubMed Central

    Min, Hongwei; Xu, Feng; Gu, Rui; Han, Xinzuo; Wang, Anqing; Liu, Kemin

    2016-01-01

    The present study aimed to explore the potential diagnostic role of diffusion tensor magnetic resonance imaging (DTI) in the early stage of modified corticosteroid-induced osteonecrosis of the femoral head (ONFH). A total of 20 beagles were randomly classified (1:1) into either an experimental group (LM), which were intramuscularly injected with lipopolysaccharide (LPS) and methylprednisolone (MPS) on three consecutive days, or control (CON) group, which were injected with saline. Magnetic resonance imaging (MRI) and DTI were performed at pre-induction and 8 and 12 weeks post-induction. Apparent diffusion coefficient (ADC) values in the range of interest in the femoral head were quantified using DTI. Proximal femora were examined for ONFH at 8 and 12 weeks. The results demonstrated that ONFH developed in four beagles at 8 weeks and in six beagles at 12 weeks, whereas no ONFH was detected in the CON group. No abnormalities were detected by MRI and DTI, and no mortality occurred. In beagles with ONFH in the LM group, the ADC values were 4.7±0.2×10−4 and 4.8±0.3×10−4 mm2/sec at 8 and 12 weeks, respectively, which were significantly increased compared with the CON group (2.5±0.3×10−4 and 2.4±0.3×10−4 mm2, respectively) and the LM group without ONFH (2.6±0.4×10−4 and 2.4±0.3×10−4 mm2, respectively) (P<0.05). The results of the present study indicated that intramuscular injection of LPS and MPS may lead to early-stage ONFH in beagles. As such, the detection of locally elevated ADC values in the femoral head may aid in the early diagnosis of ONFH. PMID:27882161

  4. The role of norepinephrine and insulin resistance in an early stage of hypertension.

    PubMed

    Penesova, Adela; Radikova, Zofia; Cizmarova, Eva; Kvetnanský, Richard; Blazicek, Pavel; Vlcek, Miroslav; Koska, Juraj; Vigas, Milan

    2008-12-01

    The interrelationship between activity of sympathetic nervous system and metabolic risk factors in youth with hypertension (HT) has been poorly studied. The aim of our present study was to assess the interrelationship between metabolic risk factors, such as insulin resistance, concentration of plasminogen activator inhibitor (PAI)-1, and catecholamines in an early stage of HT onset. An oral glucose tolerance test was performed in 17 young males with early-diagnosed nontreated HT grade 1 and 16 gender-, age-, and BMI-matched normotensive controls. Concentrations of glucose, insulin, epinephrine, norepinephrine, PAI-1, and plasma renin activity (PRA) were determined in venous plasma. Insulin sensitivity indices (ISIs) proposed by Cederholm, Matsuda, and Gutt were calculated. HT had higher baseline levels of norepinephrine, insulin (P= 0.02), and PAI-1 (P= 0.04). ISIs were lower in HT subjects (P < 0.001). Baseline concentrations of epinephrine were negatively associated with HDL cholesterol (r=-0.415, P= 0.02), ISI Matsuda (r=-0.361, P= 0.04), ISI Cederholm (r=-0.354, P= 0.04), and ISI Gutt (r=-0.429, P= 0.01), and positively with PRA (r= 0.609, P < 0.0001). Positive association was found between baseline concentrations of norepinephrine and PAI-1 (r= 0.418, P= 0.02). The sympathetic overactivity, which occurs in the early stage of HT may contribute to reduced insulin sensitivity even in young patients and intensify the undesirable development of metabolic cardiovascular risk factors and progress of the disease.

  5. Growth and physiological responses of Chinese cabbage cv. 'Chungwang' to different irradiances during early-to-middle growth stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes of the growth and morphology of Chinese cabbage cv. ‘Chungwang’ in response to five different irradiance treatments were investigated during the early and middle stages of growth. Seedlings were transplanted to 15 liter pots at the fourth leaf stage and plants were grown in controlled enviro...

  6. Towards a formal and scalable approach for quantifying software reliability at early development stages

    NASA Astrophysics Data System (ADS)

    Kong, Wende

    2009-12-01

    Problems which originate in early development stages can have a lasting influence on the reliability, safety, and cost of a software system. The requirements document, which is usually available at the requirements analysis stage, must be correct, unambiguous, and complete if the rest of the development effort is to succeed. The ability to identify faults in requirements and predict the reliability of a software system early in its development can help organizations make informative decisions about corrective actions and improve the system's quality in a cost-effective manner. A review of the literature reveals that existing approaches are unsuited to provide trustworthy reliability prediction either due to the ignorance of the requirements documents, or because of the informal and fairly sketchy way in detecting faults in requirements. This study explores the use of a preselected software reliability measurement for early software faults detection and reliability prediction. This measurement, originally a black-box testing technique, was broadly recognized for its ability to detect incomplete and ambiguous requirements, although no information was found in the literature about how to take advantage of its power. This study mathematically formalized the measurement to enhance its rigidity, repeatability and scalability and further extended it as an effective requirements faults detection technique. An automation-oriented algorithm was developed for quantifying the impact of the detected requirements faults on software reliability. The feasibility and scalability of the proposed approach for early faults detection and reliability prediction were examined using two real applications. The results clearly confirmed its feasibility and usefulness, particularly when no failure data is available and other methods are not applicable. The scalability barriers were also spotted in the approach. An empirical study was thus conducted to gain insight into the nature of the

  7. Left atrial enlargement in the early stage of hypertensive heart disease: a common but ignored condition.

    PubMed

    Su, Guanhua; Cao, Heng; Xu, Sudan; Lu, Yongxin; Shuai, Xinxin; Sun, Yufei; Liao, Yuhua; Li, Jingdong

    2014-03-01

    How to identify the early signs of hypertensive heart disease is the key to block or reverse the process of heart failure. The aim of this study was to evaluate the predictive value of left atrial (LA) enlargement in the early stage of hypertensive heart disease and to explore the correlations between LA enlargement and heart failure with normal ejection fraction (HFnEF), as well as the metabolic syndrome (MetS). Baseline clinical characteristics, biochemical indices, electrocardiographic and echocardiographic data were collected from 341 consecutive patients with essential hypertension. Among those patients, LA enlargement was more frequently presented than LV enlargement (57.2% vs 17.9%). Compared with patients without HFnEF, the prevalence of LA enlargement was higher in patients with HFnEF (82.9% vs 49.0%, P<.0001). From grade 2 to grade 3 hypertension, LA size was significantly larger in patients with MetS (P<.01) than those without. Multivariate linear regression analyses showed that age, body mass index, waist circumference, triglyceride level, and left ventricular diameter were independent predictors of LA enlargement. The simple measurement for identification of LA enlargement potentially allows early recognition of those patients at risk for heart failure, particularly among patients with MetS.

  8. Virion-incorporated alpha-enolase suppresses the early stage of HIV-1 reverse transcription.

    PubMed

    Kishimoto, Naoki; Iga, Nozomi; Yamamoto, Kengo; Takamune, Nobutoki; Misumi, Shogo

    2017-03-04

    Human immunodeficiency virus type-1 (HIV-1) particles contain not only viral-encoded but also host-encoded proteins. Interestingly, several studies showed that host proteins play a critical role in viral infectivity, replication and/or immunoreactivity in the next target cells. Here, we show that alpha-enolase (ENO1) is incorporated into HIV-1 virions and the virion-incorporated ENO1 prevents the early stage of HIV-1 reverse transcription. We found that viral particles contain two isoforms of ENO1 with different isoelectric points by two-dimensional electrophoresis. Suppression of ENO1 expression by RNA interference in the HIV-1 producer cells decreased ENO1 incorporation into virions without altering the packaging of viral structural proteins and viral production but increased viral infectivity. Although the low-level-ENO1-packaging virus maintained comparable levels of reverse transcriptase activity, viral genomic RNA and tRNA(Lys3) packaging to the control virus, its levels of early cDNA products of reverse transcription were higher than those of the control virus. In contrast, the high-level-ENO1-packaging virus, which was produced from ENO1-overexpressing cells, showed decreased infectivity and the levels of early cDNA products. Taken together, these findings reveal a novel function of ENO1 as a negative regulation factor targeting HIV-1 reverse transcription.

  9. Eag1 channels as potential early-stage biomarkers of hepatocellular carcinoma

    PubMed Central

    Chávez-López, María de Guadalupe; Zúñiga-García, Violeta; Pérez-Carreón, Julio Isael; Avalos-Fuentes, Arturo; Escobar, Yesenia; Camacho, Javier

    2016-01-01

    Hepatocellular carcinoma (HCC) is a major cause of cancer death worldwide. HCC is usually asymptomatic at potential curative stages, and it has very poor prognosis if detected later. Thus, the identification of early biomarkers and novel therapies is essential to improve HCC patient survival. Ion channels have been proposed as potential tumor markers and therapeutic targets for several cancers including HCC. Especially, the ether à-go-go-1 (Eag1) voltage-gated potassium channel has been suggested as an early marker for HCC. Eag1 is overexpressed during HCC development from the cirrhotic and the preneoplastic lesions preceding HCC in a rat model. The channel is also overexpressed in human HCC. Astemizole has gained great interest as a potential anticancer drug because it targets several proteins involved in cancer including Eag1. Actually, in vivo studies have shown that astemizole may have clinical utility for HCC prevention and treatment. Here, we will review first some general aspects of HCC including the current biomarkers and therapies, and then we will focus on Eag1 channels as promising tools in the early diagnosis of HCC. PMID:27703327

  10. Quantifying the early stages of remyelination following cuprizone-induced demyelination.

    PubMed

    Stidworthy, Mark F; Genoud, Stephane; Suter, Ueli; Mantei, Ned; Franklin, Robin J M

    2003-07-01

    The demyelinating toxin cuprizone is used increasingly in mouse studies of central nervous system remyelination. The value of this model for such studies depends on an accurate description of its quantifiable features. We therefore investigated histology and ultrastructure during the early oligodendrocyte differentiation phase of remyelination in mice given cuprizone and allowed to recover for 2 weeks. Limiting the dose of cuprizone to 0.2% overcame significant mouse morbidity and weight loss seen with a 0.4% dose, but the distribution of cuprizone-induced demyelination was anatomically variable. The caudal corpus callosum and dorsal hippocampal commissure mostly demyelinated at this dose, but the rostral corpus callosum and rostral cerebellar peduncles did not. This variable response, together with small axon diameters and hence thin myelin sheaths, hindered analysis of the progress of early remyelination. The proportion of myelinated and unmyelinated axons in defined regions followed expected trends, but there was pronounced variation between animals. Furthermore, group mean G ratios did not change as expected during the early stages of remyelination, and regression analysis revealed a complex relationship between axon diameter and myelin sheath thickness during this period. We also noted axonal pathology that persisted for at least 2 weeks after cuprizone withdrawal.

  11. Proteomic identification of abnormally expressed proteins in early-stage placenta derived from cloned cat embryos.

    PubMed

    Bang, Jae-Il; Lee, Hyo-Sang; Deb, Gautam Kumar; Ha, A-Na; Kwon, Young-Sang; Cho, Seong-Keun; Kim, Byeong-Woo; Cho, Kyu-Woan; Kong, Il-Keun

    2013-01-15

    It is unknown whether gene expression in cloned placenta during pre- and postimplantation is associated with early pregnancy failure in the cat. In this study, protein expression patterns were examined in early-stage (21-day-old) domestic cat placentas of fetuses derived from AI (CP; N = 4) and cloned embryo transfer (CEP; N = 2). Differentially expressed proteins were analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry (MS). A total of 21 proteins were aberrantly expressed (P < 0.05) by >1.5-fold in CEP compared with CP. Compared with CP, 12 proteins were upregulated in CEP (peptidyl-prolyl cis-trans isomerase A, annexin A2, protein DJ-1, adenylate kinase isoenzyme 1, protein disulfide-isomerase A3, actin cytoplasmic 1, serum albumin, protein disulfide-isomerase A6, and triosephosphate isomerase), and nine proteins were downregulated (triosephosphate isomerase; heterogeneous nuclear ribonucleoprotein H; tropomyosin alpha-4; triosephosphate isomerase 1; 60 kDa heat shock protein, mitochondrial; serum albumin; calumenin; keratin type 1; and prohibitin). The identities of the differentially expressed proteins were validated by peptide mass fingerprinting using matrix-assisted laser desorption/ionization-TOF/TOF MS/MS. The abnormally expressed proteins identified in this study might be associated with impaired development and dysfunction of CEP during early pregnancy. Abnormal protein expression might also induce fetal loss and contribute to failure to maintain pregnancy to term.

  12. Amygdalohippocampal MR volume measurements in the early stages of Alzheimer disease

    SciTech Connect

    Lehericy, S.; Baulac, M.; Chiras, J.; Pierot, L.; Martin, N.; Pillon, B.; Deweer, B.; Dubois, B.; Marsault, C.

    1994-05-01

    To evaluate the accuracy of hippocampal and amygdala volume measurements in diagnosing patients in the early stages of Alzheimer disease. Measurements of the hippocampal formation, amygdala, amygdalohippocampal complex (the two measurements summed), caudate nucleus, and ventricles, normalized for total intracranial volume, were obtained on coronal sections (1.5 T, 400/13 [repetition time/echo time], 5 mm) of 13 patients in the mild (minimental status {ge} 21) and five patients in the moderate stages of Alzheimer disease (10 < minimental status < 21), and eight age-matched control subjects. For patients with a minimental status score of 21 or greater, atrophy was significant for the amygdala and hippocampal formation (-36% and -25% for amygdala/total intracranial volume and hippocampal formation/total intracranial volume, respectively), but not for the caudate nucleus. No significant ventricular enlargement was found. For patients with a minimental status score less than 21, atrophy was more severe in all structures studied (amygdala/total intracranial volume -40%; hippocampal formation/total intracranial volume, -45%; caudate nucleus/total intracranial volume, -21%), and ventricles were enlarged (63%). No overlap was found between Alzheimer disease and control values for the amygdalohippocampal volume, even in the mild stages of the disease. In Alzheimer disease patients, hippocampal formation volumes correlated with the minimental status. Hippocampal and amygdala atrophy is marked and significant in the mild stages of Alzheimer disease. Volumetric measurements of the amygdala and the amygdalohippocampal complex appear more accurate than those of the hippocampal formation alone in distinguishing patients with Alzheimer disease. 46 refs., 8 figs., 2 tabs.

  13. Acute CO2 tolerance during the early developmental stages of four marine teleosts.

    PubMed

    Kikkawa, T; Ishimatsu, A; Kita, J

    2003-12-01

    Ocean sequestration of CO2 is proposed as a possible measure to mitigate climate changes caused by increasing atmospheric concentrations of the gas, but its impact on the marine ecosystem is unknown. We investigated the acute lethal effect of CO2 during the early developmental stages of four marine teleosts: red sea bream (Pagrus major), Japanese whiting (Sillago japonica), Japanese flounder (Paralichthys olivaceus), and eastern little tuna (Euthynnus affinis). The percentages of larvae that hatched and survived were not affected by exposure to water with a PCO2 of 1.0 kPa (= 7.5 mmHg) within 24 h. Median lethal PCO2 values for a 360-min exposure were 1.4 kPa (cleavage), 5.1 kPa (embryo), 7.3 kPa (preflexion), 4.2 kPa (flexion), 4.6 kPa (postflexion), and 2.5 kPa (juvenile) for red sea bream; 2.4 kPa (cleavage), 4.9 kPa (embryo), 5.9 kPa (preflexion), 6.1 kPa (flexion), 4.1 kPa (postflexion), and 2.7 kPa (juvenile) for Japanese whiting; 2.8 kPa (cleavage) and > 7.0 kPa (young) for Japanese flounder; and 11.8 kPa (cleavage) for eastern little tuna. Red sea bream and Japanese whiting of all ontogenetic stages had similar susceptibilities to CO2: the most susceptible stages were cleavage and juvenile, whereas the most tolerant stages were preflexion and flexion.

  14. Ultrastructure of Fibre and Parenchyma Cell Walls During Early Stages of Culm Development in Dendrocalamus asper

    PubMed Central

    GRITSCH, CRISTINA SANCHIS; MURPHY, RICHARD J.

    2005-01-01

    • Background and Aims The anatomy of bamboo culms and the multilayered structure of fibre cell walls are known to be the main determinant factors for its physical and mechanical properties. Studies on the bamboo cell wall have focussed mainly on fully elongated and mature fibres. The main aim of this study was to describe the ultrastructure of primary and secondary cell walls in culm tissues of Dendrocalamus asper at different stages of development. • Methods The development of fibre and parenchyma tissues was classified into four stages based on light microscopy observations made in tissues from juvenile plants. The stages were used as a basis for transmission electron microscopy study on the ultrastructure of the cell wall during the process of primary and early secondary cell wall formation. Macerations and phloroglucinol–HCl staining were employed to investigate fibre cell elongation and fibre cell wall lignification, respectively. • Key Results The observations indicated that the primary wall is formed by the deposition of two distinct layers during the elongation of the internode and that secondary wall synthesis may begin before the complete cessation of internode and fibre elongation. Elongation was followed by a maturation phase characterized by the deposition of multiple secondary wall layers, which varied in number according to the cell type, location in the culm tissue and stage of shoot development. Lignification of fibre cell walls started at the period prior to the cessation of internode elongation. • Conclusions The structure of the primary cell wall was comprised of two layers. The fibre secondary cell wall began to be laid down while the cells were still undergoing some elongation, suggesting that it may act to cause the slow-down and eventual cessation of cell elongation. PMID:15665037

  15. NUCLEAR EGFR PROTEIN EXPRESSION PREDICTS POOR SURVIVAL IN EARLY STAGE NON-SMALL CELL LUNG CANCER

    PubMed Central

    Traynor, Anne M.; Weigel, Tracey L.; Oettel, Kurt R.; Yang, David T.; Zhang, Chong; Kim, KyungMann; Salgia, Ravi; Iida, Mari; Brand, Toni M.; Hoang, Tien; Campbell, Toby C.; Hernan, Hilary R.; Wheeler, Deric L.

    2013-01-01

    Introduction Nuclear EGFR (nEGFR) has been identified in various human tumor tissues, including cancers of the breast, ovary, oropharynx, and esophagus, and has predicted poor patient outcomes. We sought to determine if protein expression of nEGFR is prognostic in early stage non-small cell lung cancer (NSCLC). Methods Resected stage I and II NSCLC specimens were evaluated for nEGFR protein expression using immunohistochemistry (IHC). Cases with at least one replicate core containing ≥5% of tumor cells demonstrating strong dot-like nucleolar EGFR expression were scored as nEGFR positive. Results Twenty-three (26.1% of the population) of 88 resected specimens stained positively for nEGFR. Nuclear EGFR protein expression was associated with higher disease stage (45.5% of stage II vs. 14.5% of stage I; p=0.023), histology (41.7% in squamous cell carcinoma vs. 17.1% in adenocarcinoma; p=0.028), shorter progression-free survival (PFS) (median PFS 8.7 months [95% CI 5.1–10.7 mo] for nEGFR positive vs. 14.5 months [95% CI 9.5–17.4 mo] for nEGFR negative; hazard ratio (HR) of 1.89 [95% CI 1.15–3.10]; p=0.011), and shorter overall survival (OS) (median OS 14.1 months [95% CI 10.3–22.7 mo] for nEGFR positive vs. 23.4 months [95% CI 20.1–29.4 mo] for nEGFR negative; HR of 1.83 [95% CI 1.12–2.99]; p=0.014). Conclusions Expression of nEGFR protein was associated with higher stage and squamous cell histology, and predicted shorter PFS and OS, in this patient cohort. Nuclear EGFR serves as a useful independent prognostic variable and as a potential therapeutic target in NSCLC. PMID:23628526

  16. Efficacy of Intensity Modulated Radiation Therapy After Surgery in Early Stage of Esophageal Carcinoma;

    ClinicalTrials.gov

    2016-07-30

    Esophageal Neoplasm; Esophageal Cancer TNM Staging Primary Tumor (T) T2; Esophageal Cancer TNM Staging Primary Tumor (T) T3; Esophageal Cancer TNM Staging Regional Lymph Nodes (N) N0; Esophageal Cancer TNM Staging Distal Metastasis (M) M0

  17. In situ nanomechanical characterization of the early stages of swelling and degradation of a biodegradable polymer

    NASA Astrophysics Data System (ADS)

    Dumitru, A. C.; Espinosa, F. M.; Garcia, R.; Foschi, G.; Tortorella, S.; Valle, F.; Dallavalle, M.; Zerbetto, F.; Biscarini, F.

    2015-03-01

    The interactions of a biodegradable scaffold with cells or living tissues depend on the time-evolution of the nanoscale properties of the scaffold. We present an in situ quantitative study on the early-stage swelling and degradation of poly(lactic-co-glycolic acid) (PLGA). A novel metrology scheme based on force microscopy measurements of the patterns of PLGA nanostructures is developed to characterize the evolution of topography, volume and nanomechanical properties. The volume and nanoscale roughness show an oscillating behaviour during the first eight days of immersion; at a later stage, we observe a continuous decrease of the volume. The effective Young's modulus exhibits a monotonic decrease from an initial value of about 2.4 GPa down to 9 MPa at day 14. The oscillating behaviour of the volume before the onset of full degradation is explained by a coupled diffusion-swelling mechanism. The appearance of a second maximum in the volume evolution results from the competition between swelling and degradation.The interactions of a biodegradable scaffold with cells or living tissues depend on the time-evolution of the nanoscale properties of the scaffold. We present an in situ quantitative study on the early-stage swelling and degradation of poly(lactic-co-glycolic acid) (PLGA). A novel metrology scheme based on force microscopy measurements of the patterns of PLGA nanostructures is developed to characterize the evolution of topography, volume and nanomechanical properties. The volume and nanoscale roughness show an oscillating behaviour during the first eight days of immersion; at a later stage, we observe a continuous decrease of the volume. The effective Young's modulus exhibits a monotonic decrease from an initial value of about 2.4 GPa down to 9 MPa at day 14. The oscillating behaviour of the volume before the onset of full degradation is explained by a coupled diffusion-swelling mechanism. The appearance of a second maximum in the volume evolution results from

  18. Blood Biomarkers Associated with Cognitive Decline in Early Stage and Drug-Naive Parkinson's Disease Patients.

    PubMed

    Santiago, Jose A; Potashkin, Judith A

    2015-01-01

    Early diagnosis of Parkinson's disease (PD) continues to be a major challenge in the field. The lack of a robust biomarker to detect early stage PD patients has considerably slowed the progress toward the development of potential therapeutic agents. We have previously evaluated several RNA biomarkers in whole blood from participants enrolled in two independent clinical studies. In these studies, PD patients were medicated, thus, expression of these biomarkers in de novo patients remains unknown. To this end, we tested ten RNA biomarkers in blood samples from 99 untreated PD patients and 101 HC nested in the cross-sectional Parkinson's Progression Markers Initiative by quantitative real-time PCR. One biomarker out of ten, COPZ1 trended toward significance (nominal p = 0.009) when adjusting for age, sex, and educational level. Further, COPZ1, EFTUD2 and PTBP1 mRNAs correlated with clinical features in PD patients including the Hoehn and Yahr scale, Movement Disorder Society revision of Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and Montreal Cognitive Assessment (MoCA) score. Levels of EFTUD2 and PTBP1 were significantly higher in cognitively normal PD patients (PD-CN) compared to cognitively impaired PD patients (PD-MCI). Interestingly, blood glucose levels were significantly higher in PD and PD-MCI patients (≥ 100 mg/dL, pre-diabetes) compared to HC. Collectively, we report the association of three RNA biomarkers, COPZ1, EFTUD2 and PTBP1 with clinical features including cognitive decline in early drug-naïve PD patients. Further, our results show that drug-naïve PD and PD-MCI patients have glucose levels characteristic of pre-diabetes patients, suggesting that impaired glucose metabolism is an early event in PD. Evaluation of these potential biomarkers in a larger longitudinal study is warranted.

  19. Plasma Uromodulin Correlates With Kidney Function and Identifies Early Stages in Chronic Kidney Disease Patients

    PubMed Central

    Steubl, Dominik; Block, Matthias; Herbst, Victor; Nockher, Wolfgang Andreas; Schlumberger, Wolfgang; Satanovskij, Robin; Angermann, Susanne; Hasenau, Anna-Lena; Stecher, Lynne; Heemann, Uwe; Renders, Lutz; Scherberich, Jürgen

    2016-01-01

    Abstract Uromodulin, released from tubular cells of the ascending limb into the blood, may be associated with kidney function. This work studies the relevance of plasma uromodulin as a biomarker for kidney function in an observational cohort of chronic kidney disease (CKD) patients and subjects without CKD (CKD stage 0). It should be further evaluated if uromodulin allows the identification of early CKD stages. Plasma uromodulin, serum creatinine, cystatin C, blood-urea-nitrogen (BUN) concentrations, and estimated glomerular filtration rate (eGFR CKD-EPIcrea-cystatin) were assessed in 426 individuals of whom 71 were CKD stage 0 and 355 had CKD. Besides descriptive statistics, univariate correlations between uromodulin and biomarkers/eGFR were calculated using Pearson-correlation coefficient. Multiple linear regression modeling was applied to establish the association between uromodulin and eGFR adjusted for demographic parameters and pharmacologic treatment. Receiver-operating-characteristic (ROC) analysis adjusted for demographic parameters was performed to test if uromodulin allows differentiation of subjects with CKD stage 0 and CKD stage I. Mean uromodulin plasma levels were 85.7 ± 60.5 ng/mL for all CKD stages combined. Uromodulin was correlated with all biomarkers/eGFR in univariate analysis (eGFR: r = 0.80, creatinine: r = −0.76, BUN: r = −0.72, and cystatin C: r = −0.79). Multiple linear regression modeling showed significant association between uromodulin and eGFR (coefficient estimate β = 0.696, 95% confidence interval [CI] 0.603–0.719, P < 0.001). In ROC analysis uromodulin was the only parameter that significantly improved a model containing demographic parameters to differentiate between CKD 0° and I° (area under the curve [AUC] 0.831, 95% CI 0.746–0.915, P = 0.008) compared to creatinine, cystatin C, BUN, and eGFR (AUC for creatinine: 0.722, P = 0.056, cystatin C: 0.668, P = 0.418, BUN: 0.653, P

  20. Disruption of Smad-dependent signaling for growth of GST-P-positive lesions from the early stage in a rat two-stage hepatocarcinogenesis model

    SciTech Connect

    Ichimura, Ryohei; Mizukami, Sayaka; Takahashi, Miwa; Taniai, Eriko; Kemmochi, Sayaka; Mitsumori, Kunitoshi; Shibutani, Makoto

    2010-08-01

    To clarify the involvement of signaling of transforming growth factor (TGF)-{beta} during the hepatocarcinogenesis, the immunohistochemical distribution of related molecules was analyzed in relation with liver cell lesions expressing glutathione S-transferase placental form (GST-P) during liver tumor promotion by fenbendazole, phenobarbital, piperonyl butoxide, or thioacetamide, using rats. Our study focused on early-stage promotion (6 weeks after starting promotion) and late-stage promotion (57 weeks after starting promotion). With regard to Smad-dependent signaling, cytoplasmic accumulation of phosphorylated Smad (phospho-Smad)-2/3 - identified as Smad3 by later immunoblot analysis - increased in the subpopulation of GST-P{sup +} foci, while Smad4, a nuclear transporter of Smad2/3, decreased during early-stage promotion. By late-stage promotion, GST-P{sup +} lesions lacking phospho-Smad2/3 had increased in accordance with lesion development from foci to carcinomas, while Smad4 largely disappeared in most proliferative lesions. With regard to Smad-independent mitogen-activated protein kinases, GST-P{sup +} foci that co-expressed phospho-p38 mitogen-activated protein kinase increased during early-stage promotion; however, p38-downstream phospho-activating transcriptional factor (ATF)-2, ATF3, and phospho-c-Myc, were inversely downregulated without relation to promotion. By late-stage promotion, proliferative lesions downregulated phospho-ATF2 and phospho-c-Myc along with lesion development, as with downregulation of phospho-p38 in all lesions. These results suggest that from the early stages, carcinogenic processes were facilitated by disruption of tumor suppressor functions of Smad-dependent signaling, while Smad-independent activation of p38 was an early-stage phenomenon. GST-P{sup -} foci induced by promotion with agonists of peroxisome proliferator-activated receptor-{alpha} did not change Smad expression, suggesting an aberration in the Smad

  1. Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident

    PubMed Central

    Adachi, Kouji; Kajino, Mizuo; Zaizen, Yuji; Igarashi, Yasuhito

    2013-01-01

    The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14–15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment. PMID:23989894

  2. An Analysis of Risk and Function Information in Early Stage Design

    NASA Technical Reports Server (NTRS)

    Barrientos, Francesca; Tumer, Irem; Grantham, Katie; VanWie, Michael; Stone, Robert

    2005-01-01

    The concept of function offers a high potential for thinking and reasoning about designs as well as providing a common thread for relating together other design information. This paper focuses specifically on the relation between function and risk by examining how this information is addressed for a design team conducting early stage design for space missions. Risk information is decomposed into a set of key attributes which are then used to scrutinize the risk information using three approaches from the pragmatics sub-field of linguistics: i) Gricean, ii) Relevance Theory, and Functional Analysis. Results of this linguistics-based approach descriptively account for the context of designer communication with respect to function and risk, and offer prescriptive guidelines for improving designer communication.

  3. Early stage second-language learning improves executive control: evidence from ERP.

    PubMed

    Sullivan, Margot D; Janus, Monika; Moreno, Sylvain; Astheimer, Lori; Bialystok, Ellen

    2014-12-01

    A growing body of research has reported a bilingual advantage in performance on executive control tasks, but it is not known at what point in emerging bilingualism these advantages first appear. The present study investigated the effect of early stage second-language training on executive control. Monolingual English-speaking students were tested on a go-nogo task, sentence judgment task, and verbal fluency, before and after 6 months of Spanish instruction. The training group (n = 25) consisted of students enrolled in introductory Spanish and the control group (n = 30) consisted of students enrolled in introductory Psychology. After training, the Spanish group showed larger P3 amplitude on the go-nogo task and smaller P600 amplitude on the judgment task, indicating enhanced performance, with no changes for the control group and no differences between groups on behavioral measures. Results are discussed in terms of neural changes underlying executive control after brief second-language learning.

  4. Toxic effects of magnesium oxide nanoparticles on early developmental and larval stages of zebrafish (Danio rerio).

    PubMed

    Ghobadian, Mehdi; Nabiuni, Mohammad; Parivar, Kazem; Fathi, Mojtaba; Pazooki, Jamileh

    2015-12-01

    Magnesium oxide nanoparticles (MgONPs) are used in medicine, manufacturing and food industries. Because of their extensive application in our daily lives, environmental exposure to these nanoparticles is inevitable. The present study examined the effects of MgONPs on zebrafish (Danio rerio) early developmental stages. The results showed that, at different concentrations, MgONPs induced cellular apoptosis and intracellular reactive oxygen species. The hatching rate and survival of embryos decreased in a dose dependent manner. The 96-h LC50 value of MgONPs on zebrafish survival was 428 mg/l and the 48-h EC50 value of MgONPs on zebrafish embryo hatching rate was 175 mg/l. Moreover different types of malformation were observed in exposed embryos. The results demonstrate the toxic effects of MgONPs on zebrafish embryos and emphasize the need for further studies.

  5. [Quantitative histoenzymatic analysis of the adenohypophysis and adrenal cortex during the early stages of involution].

    PubMed

    Prochukhanov, R A; Rostovtseva, T I

    1977-11-01

    A method of quantitative histenzymatic analysis was applied for determination of the involution changes of the neuroendocrine system. The activity of NAD- and NADP-reductases, acid and alkaline phosphatases, glucose-6-phosphoric dehydrogenase, 3-OH-steroid-dehydrogenase, 11-hydroxysteroid dehydrogenases was investigated in the adenohypophysis and in the adrenal cortex of rats aged 4 and 12 months. There were revealed peculiarities attending the structural-metabolic provision of physiological reconstructions of the neuro-endocrine system under conditions of the estral cycle at the early involution stages. An initial reduction of the cell ular-vascular transport with the retention of the functional activity of the intracellular organoids was demonstrated in ageing animals.

  6. Early Stage Breast Cancer Treatments for Younger Medicare Beneficiaries with Different Disabilities

    PubMed Central

    Iezzoni, Lisa I; Ngo, Long H; Li, Donglin; Roetzheim, Richard G; Drews, Reed E; McCarthy, Ellen P

    2008-01-01

    Objective To explore how underlying disability affects treatments and outcomes of disabled women with breast cancer. Data Sources Surveillance, Epidemiology, and End Results program data, linked with Medicare files and Social Security Administration disability group. Study Design Ninety thousand two hundred and forty-three incident cases of early-stage breast cancer under age 65; adjusted relative risks and hazards ratios examined treatments and survival, respectively, for women in four disability groups compared with nondisabled women. Principal Findings Demographic characteristics, treatments, and survival varied among four disability groups. Compared with nondisabled women, those with mental disorders and neurological conditions had significantly lower adjusted rates of breast conserving surgery and radiation therapy. Survival outcomes also varied by disability type. Conclusions Compared with nondisabled women, certain subgroups of women with disabilities are especially likely to experience disparities in care for breast cancer. PMID:18479411

  7. Right Ventricular Outflow Tract Arrhythmias: Benign Or Early Stage Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia?

    PubMed

    Lin Md, Tina; Conti Md, Sergio; Cipolletta Md, Laura; Marino Md, Vittoria; Zucchetti Md, Martina; Russo Md, Eleonora; Pizzamiglio Md, Francesca; Al-Mohani Md, Ghaliah; Pala Be, Salvatore; Catto Be PhD, Valentina; Di Biase Md PhD, Luigi; Natale Md, Andrea; Tondo Md PhD Fesc, Claudio; Carbucicchio Md, Corrado

    2014-12-01

    Ventricular arrhythmias (VAs) arising from the right ventricular outflow tract (RVOT) are a common and heterogeneous entity. Idiopathic right ventricular arrhythmias (IdioVAs) are generally benign, with excellent ablation outcomes and long-term arrhythmia-free survival, and must be distinguished from other conditions associated with VAs arising from the right ventricle: the differential diagnosis with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is therefore crucial because VAs are one of the most important causes of sudden cardiac death (SCD) in young individuals even with early stage of the disease. Radiofrequency catheter ablation (RFCA) is a current option for the treatment of VAs but important differences must be considered in terms of indication, purposes and procedural strategies in the treatment of the two conditions. In this review, we comprehensively discuss clinical and electrophysiological features, diagnostic and therapeutic techniques in a compared analysis of these two entities.

  8. Polymeric composite devices for localized treatment of early-stage breast cancer

    PubMed Central

    Kan-Dapaah, Kwabena; Soboyejo, Wole

    2017-01-01

    For early-stage breast cancers mastectomy is an aggressive form of treatment. Therefore, there is a need for new treatment strategies that can enhance the use of lumpectomy by eliminating residual cancer cells with limited side effects to reduce local recurrence. Although, various radiotherapy-based methods have been developed, residual cells are found in 20–55% of the time at the first operation. Furthermore, some current treatment methods result in poor cosmesis. For the last decade, the authors have been exploring the use of polymeric composite materials in single and multi-modal implantable biomedical devices for post-operative treatment of breast cancer. In this paper, the concept and working principles of the devices, as well as selected results from experimental and numerical investigations, are presented. The results show the potential of the biomedical implants for cancer treatment. PMID:28245288

  9. Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident.

    PubMed

    Adachi, Kouji; Kajino, Mizuo; Zaizen, Yuji; Igarashi, Yasuhito

    2013-01-01

    The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14-15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment.

  10. The early stage wheel fatigue crack detection using eddy current pulsed thermography

    NASA Astrophysics Data System (ADS)

    Peng, Jianping; Zhang