Acadian Food

In short, Acadians did not allow harsh weather, poor soil conditions, and an uncertain (or even hostile) political conditions to limit their culinary choices.https://digitalcommons.library.umaine.edu/songstorysamplercollection/1027/thumbnail.jp

Alternatives to Conventional Nitrogen Fertilization on Tall Fescue and Bermudagrass

Alternatives to conventional nitrogen (N) fertilization on tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons. cv. Kentucky-31] and Bermudagrass [Cynadon dactylon (L.) Pers. cv. Vaughns # 1] were studied at the University of Tennessee Plateau Research and Education Center in Crossville, TN. Experimental period occurred from April-September 2016 and 2017, and the experimental design for each experiment was a completely randomized block design with six treatments and four replications per treatment (n = 24). For both experiments treatments were as followed: 1) control (CN) without N fertilization; 2) grass and white clover (WC) [Trifolium repens (L.) cv. Ladino-Will] at a rate of 2.2 kg ha-1; 3) grass and red clover (RC) [Trifolium pretense (L.) cv. Cinnamon Plus] at a rate of 4.5 kg ha-1; 4) grass and cowpea (CW) [Vigna unguiculata (L.) cv. \u27Iron & Clay\u27] at a rate of 56 kg ha-1 5) fertilization with broiler litter (BL) at a rate of 4,500 kg ha-1; and 6) fertilization with ammonium nitrate (AN) at a rate of 67.2 kg ha-1. Differences between least squares means by treatments for botanical composition variables of legume and grass were tested for each species. For each analysis, the dependent variable was herbage mass (HM), crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF). There were significant year x treatment interactions for each species for all dependent variables. Red clover treatments resulted in highest for total HM for 2017, which was 1986 kg ha-1 more than other treatments in tall fescue. Red Clover treatments resulted in highest for HM for 2016, 4526 kg ha-1 more than other treatments and 2017, 4289 kg ha-1 more than other treatments in bermudagrass. Treatments containing BL and AN showed no differences for total HM and CP for 2016 and 2017 in both experiments. Treatments containing CW presented over-all lower results compared to other treatments. Utilizing these results in combination with cost associated with each source could assist producers in choosing a more sustainable source of N or a method of reducing their amount and annual-overall cost associated with conventional N

On the Role of Minor Galaxy Mergers in the Formation of Active Galactic Nuclei

The large scale (~ 100 kpc) environments of Seyfert galaxies are not significantly different from those of non-Seyfert galaxies. In the context of the interaction model of the formation of active galactic nuclei (AGN), it has been proposed that AGN form via "minor mergers" of large disk galaxies with smaller companions. We test this hypothesis by comparing the nuclear spectra of 105 bright nearby galaxies with measurements of their R or r band morphological asymmetries at three successive radii. We find no significant differences in these asymmetries between the 13 Seyfert galaxies in the sample and galaxies having other nuclear spectral types (absorption, H II-region like, LINER), nor is there strong qualitative evidence that such mergers have occured among any of the Seyferts or LINERs. Thus either any minor mergers began > 1 Gyr ago and are essentially complete, or they did not occur at all, and AGN form independently of any type of interaction. Support for the latter interpretation is provided by the growing evidence that supermassive black holes exist in the cores of most elliptical and early-type spiral galaxies, which in turn suggests that nuclear activity represents a normal phase in the evolution of the bulges of massive galaxies. Galaxy mergers may increase the luminosity of Seyfert nuclei to the level of QSOs, which could explain why the latter objects appear to be found in rich environments and in interacting systems.Comment: 13 pages, 2 figures, to appear in Astrophysical Journal Letter

Iron Abundance Diagnostics in High-Redshift QSOs

The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies. We investigate the relationship between Fe/Mg and Fe/C abundance ratios and the resulting Fe II / Mg II 2800A and Fe II / 1900A-blend flux ratios, both of which have been measured in QSOs out to redshifts of approximately six. Using a galactic chemical evolution model based on a starburst in a giant elliptical galaxy, we find that these flux ratios are good tracers of the chemical enrichment of the nuclei. However, the values of these ratios measured in objects at redshifts of approximately six suggest that iron enrichment has occurred more rapidly in these objects than predicted by the assumed elliptical starburst model, under currently favored cosmologies.Comment: 2 pages, to appear in proceedings of IAU Symposium No. 222, The Interplay Among Black Holes, Stars and ISM in Galacti Nucle

The Mass Profile of the Milky Way to the Virial Radius from the Illustris Simulation

We use particle data from the Illustris simulation, combined with individual kinematic constraints on the mass of the Milky Way (MW) at specific distances from the Galactic center, to infer the radial distribution of the MW's dark matter halo mass. Our method allows us to convert any constraint on the mass of the MW within a fixed distance to a full circular velocity profile to the MW's virial radius. As primary examples, we take two recent (and discrepant) measurements of the total mass within 50 kpc of the Galaxy and find they imply very different mass profiles and stellar masses for the Galaxy. The dark-matter-only version of the Illustris simulation enables us to compute the effects of galaxy formation on such constraints on a halo-by-halo basis; on small scales, galaxy formation enhances the density relative to dark-matter-only runs, while the total mass density is approximately 20% lower at large Galactocentric distances. We are also able to quantify how current and future constraints on the mass of the MW within specific radii will be reflected in uncertainties on its virial mass: even a measurement of M(<50 kpc) with essentially perfect precision still results in a 20% uncertainty on the virial mass of the Galaxy, while a future measurement of M(<100 kpc) with 10% errors would result in the same level of uncertainty. We expect that our technique will become even more useful as (1) better kinematic constraints become available at larger distances and (2) cosmological simulations provide even more faithful representations of the observable Universe.Comment: 11 pages, 8 figures; matches version published in MNRA

Future Challenges in Managing Human Health and Performance Risks for Space Flight

The global economy forces many nations to consider their national investments and make difficult decisions regarding their investment in future exploration. To enable safe, reliable, and productive human space exploration, we must pool global resources to understand and mitigate human health & performance risks prior to embarking on human exploration of deep space destinations. Consensus on the largest risks to humans during exploration is required to develop an integrated approach to mitigating risks. International collaboration in human space flight research will focus research on characterizing the effects of spaceflight on humans and the development of countermeasures or systems. Sharing existing data internationally will facilitate high quality research and sufficient power to make sound recommendations. Efficient utilization of ISS and unique ground-based analog facilities allows greater progress. Finally, a means to share results of human research in time to influence decisions for follow-on research, system design, new countermeasures and medical practices should be developed. Although formidable barriers to overcome, International working groups are working to define the risks, establish international research opportunities, share data among partners, share flight hardware and unique analog facilities, and establish forums for timely exchange of results. Representatives from the ISS partnership research and medical communities developed a list of the top ten human health & performance risks and their impact on exploration missions. They also drafted a multilateral data sharing plan to establish guidelines and principles for sharing human spaceflight data. Other working groups are also developing methods to promote international research solicitations. Collaborative use of analog facilities and shared development of space flight research and medical hardware continues. Establishing a forum for exchange of results between researchers, aerospace physicians and program managers takes careful consideration of researcher concerns and decision maker needs. Active participation by researchers in the development of this forum is essential, and the benefit can be tremendous. The ability to rapidly respond to research results without compromising publication rights and intellectual property will facilitate timely reduction in human health and performance risks in support of international exploration missions

Salmon and the Endangered Species Act: Lessons from the Columbia Basin

Within the last decade, the Columbia Basin, once home to the world\u27s largest salmon runs, has witnessed numerous listings of its signature natural resource under the Endangered Species Act (ESA). These listings have propelled the ESA into the forefront of land and water use decisionmaking across a vast landscape of the Pacific Northwest This Article examines the Columbia Basin salmon listings and their aftermath. Specifically, it considers the effect of the ESA\u27s consultation requirements on hydroelectric, hatchery, harvest, and habitat decisionmaking. The Article draws several lessons from this examination, many of them surprising, including the assertion that the listings have produced many innovations in the implementation of the statute but few improvements in the condition of listed Columbia Basin salmon, due to the persistent sensitivity of consultation process to economic concerns. The Article concludes that this reluctance to disturb ongoing activities damaging salmon does not bode well for the continued existence of the most imperiled of the species, the Snake River runs

Avoiding Biased Clinical Machine Learning Model Performance Estimates in the Presence of Label Selection

When evaluating the performance of clinical machine learning models, one must consider the deployment population. When the population of patients with observed labels is only a subset of the deployment population (label selection), standard model performance estimates on the observed population may be misleading. In this study we describe three classes of label selection and simulate five causally distinct scenarios to assess how particular selection mechanisms bias a suite of commonly reported binary machine learning model performance metrics. Simulations reveal that when selection is affected by observed features, naive estimates of model discrimination may be misleading. When selection is affected by labels, naive estimates of calibration fail to reflect reality. We borrow traditional weighting estimators from causal inference literature and find that when selection probabilities are properly specified, they recover full population estimates. We then tackle the real-world task of monitoring the performance of deployed machine learning models whose interactions with clinicians feed-back and affect the selection mechanism of the labels. We train three machine learning models to flag low-yield laboratory diagnostics, and simulate their intended consequence of reducing wasteful laboratory utilization. We find that naive estimates of AUROC on the observed population undershoot actual performance by up to 20%. Such a disparity could be large enough to lead to the wrongful termination of a successful clinical decision support tool. We propose an altered deployment procedure, one that combines injected randomization with traditional weighted estimates, and find it recovers true model performance