379 research outputs found

    Developing and Supporting the Future Extension Professional

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    Continual disruption and change describe the new normal. Embedded in complex systems and cultures, Extension professionals are at the heart of this change for many of today\u27s issues. Relying on the traditional models for developing Extension professionals will not be enough for Extension to make a significant impact in the future. We present a model of education and training to develop and support Extension professionals as they work with individuals, organizations, and communities in the 21st century

    A multicenter comparison between Child Pugh and ALBI scores in patients treated with sorafenib for hepatocellular carcinoma

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    Background & aims: The ALBI grade was proposed as an objective means to evaluate liver function in patients with Hepatocellular Carcinoma (HCC). ALBI grade 1 vs 2 were proposed as stratification factors within the Child Pugh (CP) A class. However, the original publication did not provide comparison with the sub-classification by points (5 to 15) within the CP classification. Methods: We retrospectively analyzed data from patients treated with sorafenib for HCC from 17 centers in United Kingdom and France. Overall survival (OS) was analyzed with the Kaplan-Meier method and a Cox regression model. Discriminatory abilities of the classifications were assessed with the log likelihood ratio, Harrell’s C statistics and Akaike information criterion. Results: Data from 1,019 patients were collected, of which 905 could be assessed for both scores. 92% of ALBI grade 1 were CP A5 while ALBI 2 included a broad range of CP scores of which 44% were CP A6. Median OS was 10.2, 7.0 and 3.6 months for CP scores A5, A6 and >A6, respectively (P<0.001), Hazard Ratio (HR)=1.60 (95%CI: 1.35-1.89, P<0.001) for A6 vs A5. Median OS was 10.9, 6.6 and 3.0 months for ALBI grade 1, 2 and 3, respectively (P<0.001), HR=1.68 (1.43-1.97, P<0.001) for grade 2 vs 1. Discriminatory abilities of CP and ALBI were similar in the CP A population, but better for CP in the overall population. Conclusions: Our findings support the use CP class A as an inclusion criterion, and ALBI as a stratification factor in trials of systemic therapy

    The Metallicity of the Pleiades

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    We have measured the abundances of Fe, Si, Ni, Ti, and Na in 20 Pleiads with \teff values near solar and with low \vsini using high-resolution, high signal-to-noise echelle spectra. We have validated our procedures by also analyzing 10 field stars of a range of temperatures and metallicities that were observed by \citet{Vale05}. Our result for the Pleiades is [Fe/H] = +0.03±0.02±0.05+0.03\pm0.02\pm0.05 (statistical and systematic). The average of published measurements for the Pleiades is +0.042±0.021+0.042\pm0.021.Comment: accepted by Astron. J. for 2009-1

    The impact of a new high-resolution ocean model on the Met Office North-West European Shelf forecasting system

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    The North-West European Shelf ocean forecasting system has been providing oceanographic products for the European continental shelf seas for more than 15 years. In that time, several different configurations have been implemented, updating the model and the data assimilation components. The latest configuration to be put in operation, an eddy-resolving model at 1.5 km (AMM15), replaces the 7 km model (AMM7) that has been used for 8 years to deliver forecast products to the Copernicus Marine Environment Monitoring Service and its precursor projects. This has improved the ability to resolve the mesoscale variability in this area. An overview of this new system and its initial validation is provided in this paper, highlighting the differences with the previous version. Validation of the model with data assimilation is based on the results of 2 years (2016–2017) of trial experiments run with the low- and high-resolution systems in their operational configuration. The 1.5 km system has been validated against observations and the low-resolution system, trying to understand the impact of the high resolution on the quality of the products delivered to the users. Although the number of observations is a limiting factor, especially for the assessment of model variables like currents and salinity, the new system has been proven to be an improvement in resolving fine-scale structures and variability and provides more accurate information on the major physical variables, like temperature, salinity, and horizontal currents. AMM15 improvements are evident from the validation against high-resolution observations, available in some selected areas of the model domain. However, validation at the basin scale and using daily means penalized the high-resolution system and does not reflect its superior performance. This increment in resolution also improves the capabilities to provide marine information closer to the coast even if the coastal processes are not fully resolved by the model

    The effect of uncertain river forcing on the thermohaline properties of the North West European Shelf Seas

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    Modeling studies and observations show that the thermohaline properties of the North West European Shelf Seas (NWESS) are sensitive to surface wind and heat flux forcing, as well as river outflows that transport fresh water from land to the ocean. In previous studies, it was assumed that the variability of the thermohaline properties in response to river outflow could be adequately sampled with a high-resolution, submesoscale permitting, long-term (i.e., 30-year) deterministic hindcast. In this study, we assume that the statistical distribution of the river forcing, rather than the time series of forcing itself, is adequately constrained by a 28-year history (1991 to 2018) of river forcing created specifically for our domain. In this way, we created an ensemble of 10 lower-resolution ( 7-km), short-term (i.e., 2.5 years) hindcast models that are forced with randomly perturbed river outflows and an ensemble of surface fluxes from the 10-member ECMWF ERA5 reanalysis (the ‘Test’ ensemble) as well with a companion ensemble that is forced with the ERA5 surface forcing fluxes but unperturbed river outflows (the ‘Base’ ensemble) for the June 2016 through December 2018 time period. In both ensembles, the modeled evolution of 25-hour averaged (to partially filter out tides) temperature and salinity is realistic with peaks in summer for sea surface temperature and in winter for salinity, and annual amplitudes that are comparable to those found in other studies of the NWESS. The increased mean and standard deviation of the sea surface and bottom salinity in the Test ensemble are partly an artifact of the assumption that the errors in river forcing have a log-normal distribution that mimics the episodic nature of river outflow with a positive mean and an asymmetrical shape with a long tail towards large values. For surface density, the standard deviation in the Test ensemble was below 0.5 kg/m3, covering an areal extent larger than that for the Base ensemble throughout the year. The annual cycle of the areal extent of density in that range had a peak in summer and minima in winter, in phase with that of the river outflow forcing. Overall, the effect of uncertain river forcing on the thermohaline properties in this study is small. In order to understand the true impact of river forcings, better temporal and spatial observations of river outflow are needed

    A global Mars dust composition refined by the Alpha-Particle X-ray Spectrometer in Gale Crater

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    Modern Martian dust is similar in composition to the global soil unit and bulk basaltic Mars crust, but it is enriched in S and Cl. The Alpha Particle X-ray Spectrometer (APXS) on the Mars Science Laboratory Curiosity rover analyzed air fall dust on the science observation tray (o-tray) in Gale Crater to determine dust oxide compositions. The o-tray dust has the highest concentrations of SO3 and Cl measured in Mars dust (SO3 8.3%; Cl 1.1 wt %). The molar S/Cl in the dust (3.35 ± 0.34) is consistent with previous studies of Martian dust and soils (S/Cl = 3.7 ± 0.7). Fe is also elevated ~25% over average Mars soils and the bulk crust. These enrichments link air fall dust with the S-, Cl-, and Fe-rich X-ray amorphous component of Gale Crater soil. Dust and soil have the same S/Cl, constraining the surface concentrations of S and Cl on a global scale

    What actually confers adaptive capacity? Insights from agro-climatic vulnerability of Australian wheat

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    Vulnerability assessments have often invoked sustainable livelihoods theory to support the quantification of adaptive capacity based on the availability of capital--social, human, physical, natural, and financial. However, the assumption that increased availability of these capitals confers greater adaptive capacity remains largely untested. We quantified the relationship between commonly used capital indicators and an empirical index of adaptive capacity (ACI) in the context of vulnerability of Australian wheat production to climate variability and change. We calculated ACI by comparing actual yields from farm survey data to climate-driven expected yields estimated by a crop model for 12 regions in Australia\u27s wheat-sheep zone from 1991-2010. We then compiled data for 24 typical indicators used in vulnerability analyses, spanning the five capitals. We analyzed the ACI and used regression techniques to identify related capital indicators. Between regions, mean ACI was not significantly different but variance over time was. ACI was higher in dry years and lower in wet years suggesting that farm adaptive strategies are geared towards mitigating losses rather than capitalizing on opportunity. Only six of the 24 capital indicators were significantly related to adaptive capacity in a way predicted by theory. Another four indicators were significantly related to adaptive capacity but of the opposite sign, countering our theory-driven expectation. We conclude that the deductive, theory-based use of capitals to define adaptive capacity and vulnerability should be more circumspect. Assessments need to be more evidence-based, first testing the relevance and influence of capital metrics on adaptive capacity for the specific system of interest. This will more effectively direct policy and targeting of investment to mitigate agro-climatic vulnerability

    Beta-strength and anti-neutrino spectra from total absorption spectroscopy of a decay chain \u3csup\u3e142\u3c/sup\u3eCs→\u3csup\u3e142\u3c/sup\u3e Ba →\u3csup\u3e142\u3c/sup\u3eLa

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    Beta decays of mass A = 142 isobaric chain starting from 142Cs have been investigated by means of Modular Total Absorption Spectrometer (MTAS) and on-line mass separation at Oak Ridge National Laboratory. The beta strength distribution derived for 142Cs decay from MTAS spectra is showing significant differences in β-feeding pattern when compared to the values listed at nuclear databases. MTAS results are shifting the associated anti-neutrino energy spectrum towards lower energies. A decay pattern deduced for 142Ba is similar to earlier reported results

    Interspecific Variation in Life History Relates to Antipredator Decisions by Marine Mesopredators on Temperate Reefs

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    As upper-level predatory fishes become overfished, mesopredators rise to become the new ‘top’ predators of over-exploited marine communities. To gain insight into ensuing mechanisms that might alter indirect species interactions, we examined how behavioural responses to an upper-level predatory fish might differ between mesopredator species with different life histories. In rocky reefs of the northeast Pacific Ocean, adult lingcod (Ophiodon elongatus) are upper-level predators that use a sit-and-wait hunting mode. Reef mesopredators that are prey to adult lingcod include kelp greenling (Hexagrammos decagrammus), younger lingcod, copper rockfish (Sebastes caurinus) and quillback rockfish (S. maliger). Across these mesopredators species, longevity and age at maturity increases and, consequently, the annual proportion of lifetime reproductive output decreases in the order just listed. Therefore, we hypothesized that the level of risk taken to acquire resources would vary interspecifically in that same order. During field experiments we manipulated predation risk with a model adult lingcod and used fixed video cameras to quantify interactions between mesopredators and tethered prey (Pandalus shrimps). We predicted that the probabilities of inspecting and attacking tethered prey would rank from highest to lowest and the timing of these behaviours would rank from earliest to latest as follows: kelp greenling, lingcod, copper rockfish, and quillback rockfish. We also predicted that responses to the model lingcod, such as avoidance of interactions with tethered prey, would rank from weakest to strongest in the same order. Results were consistent with our predictions suggesting that, despite occupying similar trophic levels, longer-lived mesopredators with late maturity have stronger antipredator responses and therefore experience lower foraging rates in the presence of predators than mesopredators with faster life histories. The corollary is that the fishery removal of top predators, which relaxes predation risk, could potentially lead to stronger increases in foraging rates for mesopredators with slower life histories

    Elemental Composition and Chemical Evolution of Geologic Materials in Gale Crater, Mars: APXS Results From Bradbury Landing to the Vera Rubin Ridge

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    The Alpha Particle X-ray Spectrometer (APXS) on the rover Curiosity has analyzed the composition of geologic materials along a >20-km traverse in Gale crater on Mars. The APXS dataset after 6.5 Earth years (2,301 sols) includes 712 analyses of soil, sand, float, bedrock, and drilled/scooped fines. We present the APXS results over this duration and provide stratigraphic context for each target. We identify the best APXS measurement of each of the 22 drilled and scooped samples that were delivered to the instruments Chemistry and Mineralogy (CheMin; X-ray diffractometer) and Sample Analysis at Mars (SAM; mass spectrometer and gas chromatograph) during this period. The APXS results demonstrate that the basaltic and alkali-rich units in the Bradbury group (sols 0-750) show minimal alteration indicating an arid climate. In contrast, the Murray formation of the Mount Sharp group (sols ∼750-2,301) has compositions indicating pervasive alteration. Diagenetic features are common and show fluid interaction with the sediment after (and possibly during) lithification. A sandstone unit, the Stimson formation, overlies part of the Murray formation. This has a composition similar to the basaltic sand and soil, suggesting a shared source. Cross-cutting, fracture-associated haloes are evidence of late-stage fluid alteration after lithification of the sediment. The APXS dataset, evaluated in concert with the full science payload of Curiosity, indicates that Gale crater was habitable, and that liquid water was stable for extended periods.We are indebted to NASA-JPL, the Canadian Space Agency, and Australian Research Council (DP150104604) for supporting our work and the MSL mission. A portion of this study was conducted at the Jet Propulsion Laboratory, California Institute of Technology under a contract with the National Aeronautics and Space Administration
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