203 research outputs found

    Estimating Temporal Trend in the Presence of Spatial Complexity: A Bayesian Hierarchical Model for a Wetland Plant Population Undergoing Restoration

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    Monitoring programs that evaluate restoration and inform adaptive management are important for addressing environmental degradation. These efforts may be well served by spatially explicit hierarchical approaches to modeling because of unavoidable spatial structure inherited from past land use patterns and other factors. We developed Bayesian hierarchical models to estimate trends from annual density counts observed in a spatially structured wetland forb (Camassia quamash [camas]) population following the cessation of grazing and mowing on the study area, and in a separate reference population of camas. The restoration site was bisected by roads and drainage ditches, resulting in distinct subpopulations (“zones”) with different land use histories. We modeled this spatial structure by fitting zone-specific intercepts and slopes. We allowed spatial covariance parameters in the model to vary by zone, as in stratified kriging, accommodating anisotropy and improving computation and biological interpretation. Trend estimates provided evidence of a positive effect of passive restoration, and the strength of evidence was influenced by the amount of spatial structure in the model. Allowing trends to vary among zones and accounting for topographic heterogeneity increased precision of trend estimates. Accounting for spatial autocorrelation shifted parameter coefficients in ways that varied among zones depending on strength of statistical shrinkage, autocorrelation and topographic heterogeneity—a phenomenon not widely described. Spatially explicit estimates of trend from hierarchical models will generally be more useful to land managers than pooled regional estimates and provide more realistic assessments of uncertainty. The ability to grapple with historical contingency is an appealing benefit of this approach

    Key Success Factors and Barriers for Small Businesses: Comparative Analysis

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    AbstractThis paper analyses the current situation of small businesses, their outlook and their problems in Europe and in Russia. The number of small businesses opened, legislative system, number of self-employed without employees, influence of bureaucratic system on small business's life, unemployment and corruption are considered in this study. The object of this paper is understanding what can modify the life of small companies. Thus the analysis of every factor is useful to understand how the economy could change, what is correct and what resolutions make the life of small businesses better. The analysis is made using data from Eurostat, Rosstat, and Fedstat (an OECD institutional website), studying how values of indicators have changed during recent years. The results clearly show that the development of small companies is correlated with the development of good institutions, a sane community and trust and optimism in economy and small business sector

    Evaluation of the MODIS LAI product using independent lidar-derived LAI: A case study in mixed conifer forest

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    This study presents an alternative assessment of the MODIS LAI product for a 58,000 ha evergreen needleleaf forest located in the western Rocky Mountain range in northern Idaho by using lidar data to model (R2=0.86, RMSE=0.76) and map LAI at higher resolution across a large number of MODIS pixels in their entirety. Moderate resolution (30 m) lidar-based LAI estimates were aggregated to the resolution of the 1-km MODIS LAI product and compared to temporally-coincident MODIS retrievals. Differences in the MODIS and lidar-derived values of LAI were grouped and analyzed by several different factors, including MODIS retrieval algorithm, sun/sensor geometry, and sub-pixel heterogeneity in both vegetation and terrain characteristics. Of particular interest is the disparity in the results when MODIS LAI was analyzed according to algorithm retrieval class. We observed relatively good agreement between lidar-derived and MODIS LAI values for pixels retrieved with the main RT algorithm without saturation for LAI LAI≤4. Moreover, for the entire range of LAI values, considerable overestimation of LAI (relative to lidar-derived LAI) occurred when either the main RT with saturation or back-up algorithm retrievals were used to populate the composite product regardless of sub-pixel vegetation structural complexity or sun/sensor geometry. These results are significant because algorithm retrievals based on the main radiative transfer algorithm with or without saturation are characterized as suitable for validation and subsequent ecosystem modeling, yet the magnitude of difference appears to be specific to retrieval quality class and vegetation structural characteristics

    Active Ground Optical Remote Sensing for Improved Monitoring of Seedling Stress in Nurseries

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    Active ground optical remote sensing (AGORS) devices mounted on overhead irrigation booms could help to improve seedling quality by autonomously monitoring seedling stress. In contrast to traditionally used passive optical sensors, AGORS devices operate independently of ambient light conditions and do not require spectral reference readings. Besides measuring red (590–670 nm) and near-infrared (>760 nm) reflectance AGORS devices have recently become available that also measure red-edge (730 nm) reflectance. We tested the hypothesis that the additional availability of red-edge reflectance information would improve AGORS of plant stress induced chlorophyll breakdown in Scots pine (Pinus sylvestris). Our results showed that the availability of red-edge reflectance information improved AGORS estimates of stress induced variation in chlorophyll concentration (r2 > 0.73, RMSE < 1.69) when compared to those without (r2 = 0.57, RMSE = 2.11)

    The Identity of Proteins Associated with a Small Heat Shock Protein during Heat Stress \u3ci\u3ein Vivo\u3c/i\u3e Indicates That These Chaperones Protect a Wide Range of Cellular Functions

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    The small heat shock proteins (sHSPs) are a ubiquitous class of ATP-independent chaperones believed to prevent irreversible protein aggregation and to facilitate subsequent protein renaturation in cooperation with ATP-dependent chaperones. Although sHSP chaperone activity has been studied extensively in vitro, understanding the mechanism of sHSP function requires identification of proteins that are sHSP substrates in vivo. We have used both immunoprecipitation and affinity chromatography to recover 42 proteins that specifically interact with Synechocystis Hsp16.6 in vivo during heat treatment. These proteins can all be released from Hsp16.6 by the ATP-dependent activity of DnaK and cochaperones and are heat-labile. Thirteen of the putative substrate proteins were identified by mass spectrometry and reveal the potential for sHSPs to protect cellular functions as diverse as transcription, translation, cell signaling, and secondary metabolism. One of the putative substrates, serine esterase, was purified and tested directly for interaction with purified Hsp16.6. Hsp16.6 effectively formed soluble complexes with serine esterase in a heat-dependent fashion, thereby preventing formation of insoluble serine esterase aggregates. These data offer critical insights into the characteristics of native sHSP substrates and extend and provide in vivo support for the chaperone model of sHSP function

    The Identity of Proteins Associated with a Small Heat Shock Protein during Heat Stress \u3ci\u3ein Vivo\u3c/i\u3e Indicates That These Chaperones Protect a Wide Range of Cellular Functions

    Get PDF
    The small heat shock proteins (sHSPs) are a ubiquitous class of ATP-independent chaperones believed to prevent irreversible protein aggregation and to facilitate subsequent protein renaturation in cooperation with ATP-dependent chaperones. Although sHSP chaperone activity has been studied extensively in vitro, understanding the mechanism of sHSP function requires identification of proteins that are sHSP substrates in vivo. We have used both immunoprecipitation and affinity chromatography to recover 42 proteins that specifically interact with Synechocystis Hsp16.6 in vivo during heat treatment. These proteins can all be released from Hsp16.6 by the ATP-dependent activity of DnaK and cochaperones and are heat-labile. Thirteen of the putative substrate proteins were identified by mass spectrometry and reveal the potential for sHSPs to protect cellular functions as diverse as transcription, translation, cell signaling, and secondary metabolism. One of the putative substrates, serine esterase, was purified and tested directly for interaction with purified Hsp16.6. Hsp16.6 effectively formed soluble complexes with serine esterase in a heat-dependent fashion, thereby preventing formation of insoluble serine esterase aggregates. These data offer critical insights into the characteristics of native sHSP substrates and extend and provide in vivo support for the chaperone model of sHSP function
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