Valley Bifurcation in an O(3)O(3) σ\sigma Model: Implications for High-Energy Baryon Number Violation

The valley method for computing the total high-energy anomalous cross section $S_{anom}$ is the extension of the optical theorem to the case of instanton-antiinstanton backgrounds. As a toy model for baryon number violation in Electroweak theory, we consider a version of the $O(3)$ $\sigma$ model in which the conformal invariance is broken perturbatively. We show that at a critical energy the saddle-point values of the instanton size and instanton-antiinstanton separation bifurcate into complex conjugate pairs. This nonanalytic behavior signals the breakdown of the valley method at an energy where $S_{anom}$ is still exponentially suppressed. (Figures replaced 5/3/93).Comment: (14 pages, Los Alamos Preprint LA-UR-93-811). 3 uuencoded figures include

DRD4 genotype predicts longevity in mouse and human

Longevity is influenced by genetic and environmental factors. The brain's dopamine system may be particularly relevant, since it modulates traits (e.g., sensitivity to reward, incentive motivation, sustained effort) that impact behavioral responses to the environment. In particular, the dopamine D4 receptor (DRD4) has been shown to moderate the impact of environments on behavior and health. We tested the hypothesis that the DRD4 gene influences longevity and that its impact is mediated through environmental effects. Surviving participants of a 30-year-old population-based health survey (N = 310; age range, 90-109 years; the 90+ Study) were genotyped/resequenced at the DRD4 gene and compared with a European ancestry-matched younger population (N = 2902; age range, 7-45 years). We found that the oldest-old population had a 66% increase in individuals carrying the DRD4 7R allele relative to the younger sample (p = 3.5 × 10(-9)), and that this genotype was strongly correlated with increased levels of physical activity. Consistent with these results, DRD4 knock-out mice, when compared with wild-type and heterozygous mice, displayed a 7-9.7% decrease in lifespan, reduced spontaneous locomotor activity, and no lifespan increase when reared in an enriched environment. These results support the hypothesis that DRD4 gene variants contribute to longevity in humans and in mice, and suggest that this effect is mediated by shaping behavioral responses to the environment.Fil: Grady, Deborah L.. University of California. College of Medicine. Department of Biological Chemistry; Estados UnidosFil: Thanos, Panayotis K.. National Institute on Alcohol Abuse and Alcoholism. Laboratory of Neuroimaging; Estados Unidos. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados Unidos. Stony Brook University. Department of Psychology; Estados UnidosFil: Corrada, Maria M.. University of California. Department of Neurology; Estados UnidosFil: Barnett Jr., Jeffrey C.. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados UnidosFil: Ciobanu, Valentina. University of California. College of Medicine. Department of Biological Chemistry; Estados UnidosFil: Shustarovich, Diana. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados UnidosFil: Napoli, Anthony. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados UnidosFil: Moyzis, Alexandra G.. University of California. College of Medicine. Department of Biological Chemistry; Estados UnidosFil: Grandy, David. Oregon Health Sciences University. Physiology and Pharmacology; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Wang, Gene-Jack. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados UnidosFil: Kawas, Claudia H.. University of California. Department of Neurology; Estados UnidosFil: Chen, Chuansheng. University of California. Department of Psychology and Social Behavior; Estados UnidosFil: Dong, Qi. Beijing Normal University. National Key Laboratory of Cognitive Neuroscience and Learning; ChinaFil: Wang, Eric. University of California. College of Medicine. Department of Biological Chemistry; Estados Unidos. Aria Diagnostics Inc.; Estados Unidos. University of California. Institute of Genomics and Bioinformatics; Estados UnidosFil: Volkow, Nora D.. National Institute on Alcohol Abuse and Alcoholism. Laboratory of Neuroimaging; Estados Unidos. Brookhaven National Laboratory. Medical Department. Behavioral Neuropharmocology and Neuroimaging Laboratory; Estados Unidos. National Institute on Drug Abuse; Estados UnidosFil: Moyzis, Robert K.. University of California. College of Medicine. Department of Biological Chemistry; Estados Unidos. Beijing Normal University. National Key Laboratory of Cognitive Neuroscience and Learning; China. University of California. Institute of Genomics and Bioinformatics; Estados Unido

Sodium fast reactor safety and licensing research plan. Volume II.

Expert panels comprised of subject matter experts identified at the U.S. National Laboratories (SNL, ANL, INL, ORNL, LBL, and BNL), universities (University of Wisconsin and Ohio State University), international agencies (IRSN, CEA, JAEA, KAERI, and JRC-IE) and private consultation companies (Radiation Effects Consulting) were assembled to perform a gap analysis for sodium fast reactor licensing. Expert-opinion elicitation was performed to qualitatively assess the current state of sodium fast reactor technologies. Five independent gap analyses were performed resulting in the following topical reports: (1) Accident Initiators and Sequences (i.e., Initiators/Sequences Technology Gap Analysis), (2) Sodium Technology Phenomena (i.e., Advanced Burner Reactor Sodium Technology Gap Analysis), (3) Fuels and Materials (i.e., Sodium Fast Reactor Fuels and Materials: Research Needs), (4) Source Term Characterization (i.e., Advanced Sodium Fast Reactor Accident Source Terms: Research Needs), and (5) Computer Codes and Models (i.e., Sodium Fast Reactor Gaps Analysis of Computer Codes and Models for Accident Analysis and Reactor Safety). Volume II of the Sodium Research Plan consolidates the five gap analysis reports produced by each expert panel, wherein the importance of the identified phenomena and necessities of further experimental research and code development were addressed. The findings from these five reports comprised the basis for the analysis in Sodium Fast Reactor Research Plan Volume I

Diversifying and perennializing plants in agroecosystems alters retention of new C and N from crop residues

Managing soils to retain new plant inputs is key to moving toward a sustainable and regenerative agriculture. Management practices, like diversifying and perennializing agroecosystems, may affect the decomposer organisms that regulate how new residue is converted to persistent soil organic matter. Here we tested whether 12 years of diversifying/perennializing plants in agroecosystems through extended rotations or grassland restoration would decrease losses of new plant residue inputs, and thus increase retention of carbon (C) and nitrogen (N) in soil. We tracked dual-labelled (13C and 15N), isotopically enriched wheat (Triticum aestivum) residue in situ for two years as it decomposed in three agroecosystems: maize-soybean rotation (CS), maize-soybean-wheat plus red clover and cereal rye cover crops (CSW2), and spring fallow management with regeneration of natural grassland species (7-10 species; SF). We measured losses of wheat residue (Cwheat and Nwheat) in leached soil solution and greenhouse gas fluxes, as well as how much was recovered in microbial biomass and bulk soil at 5-cm increments down to 20 cm. CSW2 and SF both had unique, significant effects on residue decomposition and retention dynamics that were clear only when using nuanced metrics that tease apart subtle differences. For example, SF retained a greater portion of Cwheat in 0-5 cm surface soils (155%, p=0.035) and narrowed the Cwheat to Nwheat ratio (p<0.030) compared to CS. CSW2 increased an index of carbon-retention-efficiency, Cwheat retained in the mesocosm divided by total measured, from 0.18 to 0.27 (49%, p=0.001), compared to CS. Overall, we found that diversifying and extending duration of living plants in agroecosystems can lead to greater retention of new residue inputs in subtle ways that require further investigation to fully understand.This is the peer-reviewed version of the following article: McDaniel, Marshall D., Jeffrey A. Bird, Jennifer Pett-Ridge, Erika Marin-Spiotta, Tom M. Schmidt, and A. Stuart Grandy. "Diversifying and perennializing plants in agroecosystems alters retention of new C and N from crop residues." Ecological Applications: e2784. It has been published in final form at DOI: 10.1002/eap.2784. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Copyright 2022 Posted with permission

Diversifying and perennializing plants in agroecosystems alters retention of new C and N from crop residues

Managing soils to retain new plant inputs is key to moving toward a sustainable and regenerative agriculture. Management practices, like diversifying and perennializing agroecosystems, may affect the decomposer organisms that regulate how new residue is converted to persistent soil organic matter. Here we tested whether 12 years of diversifying/perennializing plants in agroecosystems through extended rotations or grassland restoration would decrease losses of new plant residue inputs and, thus, increase retention of carbon (C) and nitrogen (N) in soil. We tracked dual-labeled (13C and 15N), isotopically enriched wheat (Triticum aestivum) residue in situ for 2 years as it decomposed in three agroecosystems: maize–soybean (CS) rotation, maize–soybean–wheat plus red clover and cereal rye cover crops (CSW2), and spring fallow management with regeneration of natural grassland species (seven to 10 species; SF). We measured losses of wheat residue (Cwheat and Nwheat) in leached soil solution and greenhouse gas fluxes, as well as how much was recovered in microbial biomass and bulk soil at 5-cm increments down to 20 cm. CSW2 and SF both had unique, significant effects on residue decomposition and retention dynamics that were clear only when using nuanced metrics that able to tease apart subtle differences. For example, SF retained a greater portion of Cwheat in 0–5 cm surface soils (155%, p = 0.035) and narrowed the Cwheat to Nwheat ratio (p < 0.030) compared to CS. CSW2 increased an index of carbon-retention efficiency, Cwheat retained in the mesocosm divided by total measured, from 0.18 to 0.27 (49%, p = 0.001), compared to CS. Overall, we found that diversifying and extending the duration of living plants in agroecosystems can lead to greater retention of new residue inputs in subtle ways that require further investigation to fully understand.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175922/1/eap2784.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175922/2/eap2784-sup-0001-AppendixS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175922/3/eap2784_am.pd

Fungal community response to long‐term soil warming with potential implications for soil carbon dynamics

Abstract The direction and magnitude of climate warming effects on ecosystem processes such as carbon cycling remain uncertain. Soil fungi are central to these processes due to their roles as decomposers of soil organic matter, as mycorrhizal symbionts, and as determinants of plant diversity. Yet despite their importance to ecosystem functioning, we lack a clear understanding of the long‐term response of soil fungal communities to warming. Toward this goal, we characterized soil fungal communities in two replicated soil warming experiments at the Harvard Forest (Petersham, Massachusetts, USA) which had experienced 5°C above ambient soil temperatures for 5 and 20 yr at the time of sampling. We assessed fungal diversity and community composition by sequencing the ITS2 region of rDNA using Illumina technology, along with soil C concentrations and chemistry. Three main findings emerged: (1) long‐, but not short‐term warming resulted in compositional shifts in the soil fungal community, particularly in the saprotrophic and unknown components of the community; (2) soil C concentrations and the total C stored in the organic horizon declined in response to both short‐ (5 yr) and long‐term (20 yr) warming; and (3) following long‐term warming, shifts in fungal guild relative abundances were associated with substantial changes in soil organic matter chemistry, particularly the relative abundance of lignin. Taken together, our results suggest that shifts with warming in the relative abundance of fungal functional groups and dominant fungal taxa are related to observed losses in total soil C

Fungal community response to long‐term soil warming with potential implications for soil carbon dynamics

Abstract The direction and magnitude of climate warming effects on ecosystem processes such as carbon cycling remain uncertain. Soil fungi are central to these processes due to their roles as decomposers of soil organic matter, as mycorrhizal symbionts, and as determinants of plant diversity. Yet despite their importance to ecosystem functioning, we lack a clear understanding of the long‐term response of soil fungal communities to warming. Toward this goal, we characterized soil fungal communities in two replicated soil warming experiments at the Harvard Forest (Petersham, Massachusetts, USA) which had experienced 5°C above ambient soil temperatures for 5 and 20 yr at the time of sampling. We assessed fungal diversity and community composition by sequencing the ITS2 region of rDNA using Illumina technology, along with soil C concentrations and chemistry. Three main findings emerged: (1) long‐, but not short‐term warming resulted in compositional shifts in the soil fungal community, particularly in the saprotrophic and unknown components of the community; (2) soil C concentrations and the total C stored in the organic horizon declined in response to both short‐ (5 yr) and long‐term (20 yr) warming; and (3) following long‐term warming, shifts in fungal guild relative abundances were associated with substantial changes in soil organic matter chemistry, particularly the relative abundance of lignin. Taken together, our results suggest that shifts with warming in the relative abundance of fungal functional groups and dominant fungal taxa are related to observed losses in total soil C

Data For: Diversifying and Perennializing Plants in Agroecosystems Alters Retention of New C and N from Crop

These data are soil, CO2 efflux, dissolved organic carbon leaching, and various other measures from a mesocosm experiment performed in long-term (12-years) crop diversity experiment near Hickory Corners, MI, United States.Briefly, we tracked dual-labelled (13C and 15N), isotopically enriched wheat (Triticum aestivum) residue in situ for two years as it decomposed in three agroecosystems: maize-soybean rotation (CS), maize-soybean-wheat plus red clover and cereal rye cover crops (CSW2), and spring fallow management with regeneration of natural grassland species (7-10 species; SF). We measured losses of wheat residue (Cwheat and Nwheat) in leached soil solution and greenhouse gas fluxes, as well as how much was recovered in microbial biomass and bulk soil at 5-cm increments down to 20 cm. COLLECTION INFORMATION: Time period(s): 2011 to 2013 Location(s): Hickory Corners, MI, United States Long-term Experiment: Cropping Biodiversity Gradient Experiment Further Site Information: https://lter.kbs.msu.edu/research/long-term-experiments/biodiversity-gradient/ </ul

Increasing the spatial and temporal impact of ecological research: A roadmap for integrating a novel terrestrial process into an Earth system model

Terrestrial ecosystems regulate Earth’s climate through water, energy, and biogeochemical transformations. Despite a key role in regulating the Earth system, terrestrial ecology has historically been underrepresented in the Earth system models (ESMs) that are used to understand and project global environmental change. Ecology and Earth system modeling must be integrated for scientists to fully comprehend the role of ecological systems in driving and responding to global change. Ecological insights can improve ESM realism and reduce process uncertainty, while ESMs offer ecologists an opportunity to broadly test ecological theory and increase the impact of their work by scaling concepts through time and space. Despite this mutualism, meaningfully integrating the two remains a persistent challenge, in part because of logistical obstacles in translating processes into mathematical formulas and identifying ways to integrate new theories and code into large, complex model structures. To help overcome this interdisciplinary challenge, we present a framework consisting of a series of interconnected stages for integrating a new ecological process or insight into an ESM. First, we highlight the multiple ways that ecological observations and modeling iteratively strengthen one another, dispelling the illusion that the ecologist’s role ends with initial provision of data. Second, we show that many valuable insights, products, and theoretical developments are produced through sustained interdisciplinary collaborations between empiricists and modelers, regardless of eventual inclusion of a process in an ESM. Finally, we provide concrete actions and resources to facilitate learning and collaboration at every stage of data- model integration. This framework will create synergies that will transform our understanding of ecology within the Earth system, ultimately improving our understanding of global environmental change, and broadening the impact of ecological research.Terrestrial ecology has historically been underrepresented in the Earth system models (ESMs) that are used to understand and project global environmental change. The prevalent existing paradigm in ecology- ESM integration separates tasks along disciplinary lines. We recommend a new set of steps for ecology- ESM integration that shifts away from this historical paradigm toward a more collaborative one in which empiricists and modelers are involved in coproducing knowledge at every stage of data collection, theory development, and model integration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/171207/1/gcb15894_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/171207/2/gcb15894.pd