40 research outputs found
GEnZ Explorer: A Tool for Visualizing Agroclimate to Inform Research and Regulatory Risk Assessment
The Relation Between Quasar and Merging Galaxy Luminosity Functions and the Merger-Induced Star Formation Rate of the Universe
Using a model for self-regulated growth of black holes (BHs) in mergers
involving gas-rich galaxies, we study the relationship between quasars and the
population of merging galaxies and predict the merger-induced star formation
rate density of the Universe. Mergers drive nuclear gas inflows, fueling
starbursts and 'buried quasars' until accretion feedback expels the gas,
rendering a briefly visible optical quasar. Star formation is shut down and
accretion declines, leaving a passively evolving remnant with properties
typical of red, elliptical galaxies. Based on evolution of these events in our
simulations, we demonstrate that the observed statistics of merger rates,
luminosity functions (LFs) and mass functions, SFR distributions, specific
SFRs, quasar and quasar host galaxy LFs, and elliptical/red galaxy LFs are
self-consistent and follow from one another as predicted by the merger
hypothesis. We use our simulations to de-convolve both quasar and merging
galaxy LFs to determine the birthrate of black holes of a given final mass and
merger rates as a function of stellar mass. We use this to predict the merging
galaxy LF in several observed wavebands, color-magnitude relations, mass
functions, absolute and specific SFR distributions and SFR density, and quasar
host galaxy LFs, as a function of redshift from z=0-6. We invert this and
predict e.g. quasar LFs from observed merger LFs or SFR distributions. Our
results agree well with observations, but idealized models of quasar
lightcurves are ruled out by comparison of merger and quasar observations at
>99.9% confidence. Using only observations of quasars, we estimate the
contribution of mergers to the SFR density of the Universe even to high
redshifts z~4.Comment: 26 pages, 15 figures, matches version accepted to Ap
Climate Indicators for Agriculture
The Climate Indicators for Agriculture report presents 20 indicators of climate change, carefully selected across multiple agricultural production types and food system elements in the United States. Together, they represent an overall view of how climate change is influencing U.S. agriculture and food systems. Individually, they provide useful information to support management decisions for a variety of crop and livestock production systems. The report includes multiple categories of indicators, including physical indicators (e.g., temperature, precipitation), crop and livestock (e.g., animal heat stress), biological indicators (e.g., pests), phenological indicators (e.g. seasonality), and socioeconomic indicators (e.g., total factor productivity)
Genetic Biocontrol for Invasive Species
Invasive species are increasingly affecting agriculture, food, fisheries, and forestry resources throughout the world. As a result of global trade, invasive species are often introduced into new environments where they become established and cause harm to human health, agriculture, and the environment. Prevention of new introductions is a high priority for addressing the harm caused by invasive species, but unfortunately efforts to prevent new introductions do not address the economic harm that is presently manifested where invasive species have already become established. Genetic biocontrol can be defined as the release of organisms with genetic methods designed to disrupt the reproduction of invasive populations. While these methods offer the potential to control or even eradicate invasive species, there is a need to ensure that genetic biocontrol methods can be deployed in a way that minimizes potential harm to the environment. This review provides an overview of the state of genetic biocontrol, focusing on several approaches that were the subject of presentations at the Genetic Biocontrol for Invasive Species Workshop in Tarragona, Spain, March 31st, 2019, a workshop sponsored by the OECDâs Co-operative Research Program on Biological Resource Management for Sustainable Agricultural Systems. The review considers four different approaches to genetic biocontrol for invasive species; sterile-release, YY Males, Trojan Female Technique, and gene drive. The different approaches will be compared with respect to the efficiency each affords as a genetic biocontrol tool, the practical utility and cost/benefits associated with implementation of the approach, and the regulatory considerations that will need to be addressed for each. The opinions expressed and arguments employed in this publication are the sole responsibility of the authors and do not necessarily reflect those of the OECD or of the governments of its Member countries
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SPHEREx: NASA's near-infrared spectrophotometric all-sky survey
SPHEREx, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and ices Explorer, is a NASA MIDEX mission planned for launch in 2024. SPHEREx will carry out the first all-sky spectral survey at wavelengths between 0.75”m and 5”m with spectral resolving power ~40 between 0.75 and 3.8”m and ~120 between 3.8 and 5”m At the end of its two-year mission, SPHEREx will provide 0.75-to-5”m spectra of each 6.â2 x 6.â2 pixel on the sky - 14 billion spectra in all. This paper updates an earlier description of SPHEREx presenting changes made during the mission's Preliminary Design Phase, including a discussion of instrument integration and test ow and a summary of the data processing, analysis, and distribution plans
Climate Indicators for Agriculture
The Climate Indicators for Agriculture report presents 20 indicators of climate change, carefully selected across multiple agricultural production types and food system elements in the United States. Together, they represent an overall view of how climate change is influencing U.S. agriculture and food systems. Individually, they provide useful information to support management decisions for a variety of crop and livestock production systems. The report includes multiple categories of indicators, including physical indicators (e.g., temperature, precipitation), crop and livestock (e.g., animal heat stress), biological indicators (e.g., pests), phenological indicators (e.g. seasonality), and socioeconomic indicators (e.g., total factor productivity)
Genetic Biocontrol for Invasive Species
Invasive species are increasingly affecting agriculture, food, fisheries, and forestry resources throughout the world. As a result of global trade, invasive species are often introduced into new environments where they become established and cause harm to human health, agriculture, and the environment. Prevention of new introductions is a high priority for addressing the harm caused by invasive species, but unfortunately efforts to prevent new introductions do not address the economic harm that is presently manifested where invasive species have already become established. Genetic biocontrol can be defined as the release of organisms with genetic methods designed to disrupt the reproduction of invasive populations. While these methods offer the potential to control or even eradicate invasive species, there is a need to ensure that genetic biocontrol methods can be deployed in a way that minimizes potential harm to the environment. This review provides an overview of the state of genetic biocontrol, focusing on several approaches that were the subject of presentations at the Genetic Biocontrol for Invasive Species Workshop in Tarragona, Spain, March 31st, 2019, a workshop sponsored by the OECDâs Co-operative Research Program on Biological Resource Management for Sustainable Agricultural Systems. The review considers four different approaches to genetic biocontrol for invasive species; sterile-release, YY Males, Trojan Female Technique, and gene drive. The different approaches will be compared with respect to the efficiency each affords as a genetic biocontrol tool, the practical utility and cost/benefits associated with implementation of the approach, and the regulatory considerations that will need to be addressed for each. The opinions expressed and arguments employed in this publication are the sole responsibility of the authors and do not necessarily reflect those of the OECD or of the governments of its Member countries
Climate Indicators for Agriculture
The Climate Indicators for Agriculture report presents 20 indicators of climate change, carefully selected across multiple agricultural production types and food system elements in the United States. Together, they represent an overall view of how climate change is influencing U.S. agriculture and food systems. Individually, they provide useful information to support management decisions for a variety of crop and livestock production systems. The report includes multiple categories of indicators, including physical indicators (e.g., temperature, precipitation), crop and livestock (e.g., animal heat stress), biological indicators (e.g., pests), phenological indicators (e.g. seasonality), and socioeconomic indicators (e.g., total factor productivity).This report is from Walsh, M. K., P. Backlund, L. Buja, A. DeGaetano, R. Melnick, L. Prokopy, E. Takle, D. Todey, L. Ziska. 2020. Climate Indicators for Agriculture. USDA Technical Bulletin 1953. Washington, DC. 70 pages. DOI:10.32747/2020.7201760.ch.</p