127,341 research outputs found
ENERGY SUPPLEMENTATION STRATEGIES FOR WHEAT PASTURE STOCKER CATTLE UNDER UNCERTAIN FORAGE AVAILABILITY
No full textEnergy supplementation provides a means of reducing production risk of growing stocker cattle on winter wheat pasture. This study addresses the issue of risk aversion and energy supplement input use. Differences in supplementation practices induced by risk aversion and the effects of cattle and feed market conditions are examined. Results show that supplementation practices are likely to be similar across producers, irrespective of their risk attitudes. Cattle and feed market conditions, however, markedly affect supplementation practices. These findings provide information for assisting stockmen in identifying efficient supplement strategies.Risk, Wheat pasture grazing, Numerical integration, Energy supplementation, Livestock Production/Industries,
Optimal Grazing Termination Date for Dual-Purpose Winter Wheat Production
No full textDual-purpose winter wheat (fall-winter forage plus grain) production is an important economic enterprise in the southern Great Plains. Grazing termination to enable grain production is a critical decision. The objective is to determine the optimal grazing termination date for dual-purpose wheat. The value of knowing the occurrence of first hollow stem (FHS), a wheat growth threshold for grazing termination, is also determined. Results indicate that for most price situations grazing should be terminated at or before FHS. Marginal wheat returns from extended grazing were negative and the value of FHS information ranges from 10 per acre.dual-purpose, first hollow stem, plateau function, stocker cattle, value of information, wheat, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Land Economics/Use, Livestock Production/Industries, Production Economics, Q12, Q16,
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Letter From Arthur Frederick Stocker to Emmett L. Bennett Jr., July 31, 1958
No full textStocker invites Bennett to contribute an hour-long talk on his work on Linear B at the upcoming meeting of the Southern Section of CAMWS in Nashville.Classic
GPP: Site-scale and global model outputs from P-model used for Stocker et al. (2019) Nature Geosci.
No full text<p><strong>Data from article Stocker et al. (in review) *Nature Geosci.*</strong></p>
<p>The datasets provided here include:</p>
<ul>
<li>Site-level GPP model results from the P-model (Wang et al., 2017)</li>
<li>Model outputs from global simulations with the P-model (Wang et al., 2017) as implemented for the study by Stocker et al. (2019)</li>
</ul>
<p>This data may be used to partly reproduce results presented in Stocker et al. (2019) <em>Nature Geosci</em>. "Partly" because we used data for our analysis that was not open access but was confidentially shared with us. This includes remote sensing-based GPP estimates from the BESS and VPM models. Other open access data that was used for the analysis may not be distributed under this DOI. This includes FLUXNET 2015 data and MODIS data.</p>
<p>For reproducing results of Stocker et al. (2019) regarding site-scale evaluations, run for example the scripts `plot_bias_all.R` and `plot_bias_problem.R`, available from <a href="https://github.com/stineb/soilm_global">Github</a> or <a href="http://doi.org/10.5281/zenodo.1423328">Zenodo</a>, using CSV files provided here (see comments in scripts). For more insight, including analysis of global simulation outputs, see RMarkdown file `si_soilm_global.Rmd`. This renders the supplementary information PDF document provided along with Stocker et al. (2019), which is available also on <a href="http://rpubs.com/stineb/si_soilm_global2">RPubs</a>.</p>
<p>The present datasets are prepared by script `prepare_data_openaccess.R ` on <a href="https://github.com/stineb/soilm_global">Github</a> or <a href="https://zenodo.org/record/1286966#.W6TFipMzbUI">Zenodo</a>.</p>
<p><strong>Data description</strong></p>
<p><em>Site-level data</em></p>
<p>Data is provided as CSV files:</p>
<ul>
<li>`gpp_daily_fluxnet_stocker18natgeo.csv`: Daily data for full time series (not including MODIS GPP)</li>
<li>`gpp_8daily_fluxnet_stocker18natgeo.csv`: Data aggregated to 8-day periods corresponding to MODIS dates (including MODIS GPP)</li>
<li>`gpp_alg_daily_fluxnet_stocker18natgeo.csv`: Data filtered to periods with substantial soil moisture effects ("fLUE droughts" following Stocker et al. (2018a))</li>
<li>`gpp_alg_8daily_fluxnet_stocker18natgeo.csv`: Data aggregated to 8-day periods and filtered to periods with substantial soil moisture effects.</li>
</ul>
<p>Each column is a variable with the following name and units (not all variables are available in all files):</p>
<ul>
<li>`site_id`: FLUXNET site ID </li>
<li>`date`: Date of measurement, units: YYYY-MM-DD</li>
<li>`gpp_pmodel` and `gpp_modis`: Simulated GPP from the P-model and MODIS (see Stocker et al. (2018b), Methods, RS models), units: g C m-2 d-1 (mean across 8 day periods in respective files)</li>
<li>`aet_splash`: Simulated actual evapotranspiration from the SPLASH model (Davis et al., 2017), units: mm d-1</li>
<li>`pet_splash`: Simulated potential evapotranspiration from the SPLASH model (Davis et al., 2017), units: mm d-1</li>
<li>`soilm_splash`: Soil moisture simulated by the SPLASH model (Davis et al., 2017), normalised to vary between zero and one at the maximum water holding capacity, unitless.</li>
<li>`flue`: fLUE estimate from Stocker et al. (2018). Estimates soil moisture stress on light use efficiency from flux data, unitless.</li>
<li>`beta_a`, `beta_b`, and `beta_c`: Empirical soil moisture stress, used as multiplier to simulated GPP as described in Stocker et al. (2018b), unitless.</li>
</ul>
<p><em>Global P-model simulation outputs</em></p>
<p>GPP and soil moisture output is provided as NetCDF files for simulations s0, and s1b (see Stocker et al. (2018b)). All meta information is provided therein. Files for simulation s1b are names as follows (for outputs from other simulations replace s1b with other simulation name). The fraction of each gridcell covered by land (not open water or ice) is given by separate file `s1b_fapar3g_v2_global.fland.nc`.</p>
<ul>
<li>`s1b_fapar3g_v2_global.d.gpp.nc`: Daily GPP from simulation s1b.</li>
<li>`s1b_fapar3g_v2_global.d.wcont.nc`: Daily soil moisture from simulation s1b (is identical in other simulations, therefore not provided.)</li>
</ul>
<p>Due to limited total file size allowed for uploads to Zenodo, only outputs from s1b are provided here. Other outputs may be obtained upon request addressed to [email protected]. </p>
<p><strong>References</strong></p>
<p>Davis, T. W. et al. Simple process-led algorithms for simulating habitats (SPLASH v.1.0): robust indices of radiation, evapotranspiration and plant-available moisture. Geoscientific Model Development 10, 689–708 (2017).<br>
Hufkens, K. khufkens/gee_subset: Google Earth Engine subset script & library. (2017). doi:10.5281/zenodo.833789Running, S. W. et al. A Continuous Satellite-Derived Measure of Global Terrestrial Primary Production. Bioscience 54, 547–560 (2004).<br>
Stocker, B. et al., Quantifying soil moisture impacts on light use efficiency across biomes, New Phytologist, doi: 10.1111/nph.15123 (2018a).<br>
Stocker, B. et al., Satellite monitoring underestimates the impact of drought on terrestrial primary productivity, Nature Geoscience (2019).<br>
Wang, H. et al. Towards a universal model for carbon dioxide uptake by plants. Nat Plants 3, 734–741 (2017).<br>
</p>
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Use of a Producer Survey to Reconcile Differences in Experiment Station Yield Estimates
No full textAverage producer practice reveals that the expected returns are greater from dual-purpose wheat grown for both forage and grain than for grain-only wheat. Variety trials report an 11 bushel per acre yield advantage and hence economic advantage for grain-only. Research was conducted to reconcile the inconsistency.direct elicitation method, dual-purpose, simulation, stocker steers, survey, triangular distribution, wheat, Farm Management, Livestock Production/Industries, Q10, Q12,
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Klosterhalfen B, Hartung P, Weis J, Stocker G, et al. Related Articles, Links Extracellular matrix proteins in colorectal carcinomas. Expression of tenascin and fibronectin isoforms
No full textBernard Williams
No full textAn edited multi-author volume assessing the moral philosophy of the late British philosopher Bernard Williams. Contributors: Adrian Moore, John Skorupski, Alan Thomas, Robert B Louden, Michael Stocker, A. A. Long, Edward Crai
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