Contextual organismality: Beyond pattern to process in the emergence of organisms

Biologists have taken the concept of organism largely for granted. However, advances in the study of chimerism, symbiosis, bacterial-eukaryote associations, and microbial behavior have prompted a redefinition of organisms as biological entities exhibiting low conflict and high cooperation among their parts. This expanded view identifies organisms in evolutionary time. However, the ecological processes, mechanisms, and traits that drive the formation of organisms remain poorly understood. Recognizing that organismality can be context dependent, we advocate elucidating the ecological contexts under which entities do or do not act as organisms. Here we develop a "contextual organismality" framework and provide examples of entities, such as honey bee colonies, tumors, and bacterial swarms, that can act as organisms under specific life history, resource, or other ecological circumstances. We suggest that context dependence may be a stepping stone to the development of increased organismal unification, as the most integrated biological entities generally show little context dependence. Recognizing that organismality is contextual can identify common patterns and testable hypotheses across different entities. The contextual organismality framework can illuminate timeless as well as pressing issues in biology, including topics as disparate as cancer emergence, genomic conflict, evolution of symbiosis, and the role of the microbiota in impacting host phenotype.John Templeton FoundationVersion of record online: 27 October 2016; published open access.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

SIMPle Dark Matter: Self-Interactions and keV Lines

We consider a simple supersymmetric hidden sector: pure SU(N) gauge theory. Dark matter is made up of hidden glueballinos with mass $m_X$ and hidden glueballs with mass near the confinement scale $\Lambda$. For $m_X \sim 1\,\text{TeV}$ and $\Lambda \sim 100\,\text{MeV}$, the glueballinos freeze out with the correct relic density and self-interact through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order $\Lambda^2 / m_X \sim 10\,\text{keV}$. We show that the radiative decays of the excited state can explain the observed 3.5 keV X-ray line signal from clusters of galaxies, Andromeda, and the Milky Way.Comment: v1: 6 pages, 2 figures; v2: added references, published version; v3: note adde

Decomposition of coarse woody debris in a long-term litter manipulation experiment: A focus on nutrient availability

The majority of above-ground carbon in tropical forests is stored in wood, which is returned to the atmosphere during decomposition of coarse woody debris. However, the factors controlling wood decomposition have not been experimentally manipulated over time scales comparable to the length of this process.We hypothesized that wood decomposition is limited by nutrient availability and tested this hypothesis in a long-term litter addition and removal experiment in a lowland tropical forest in Panama. Specifically, we quantified decomposition using a 15-year chronosequence of decaying boles, and measured respiration rates and nutrient limitation of wood decomposer communities.The long-term probability that a dead tree completely decomposed was decreased in plots where litter was removed, but did not differ between litter addition and control treatments. Similarly, respiration rates of wood decomposer communities were greater in control treatments relative to litter removal plots; litter addition treatments did not differ from either of the other treatments. Respiration rates increased in response to nutrient addition (nitrogen, phosphorus, and potassium) in the litter removal and addition treatments, but not in the controls.Established decreases in concentrations of soil nutrients in litter removal plots and increased respiration rates in response to nutrient addition suggest that reduced rates of wood decomposition after litter removal were caused by decreased nutrient availability. The effects of litter manipulations differed directionally from a previous short-term decomposition study in the same plots, and reduced rates of bole decomposition in litter removal plots did not emerge until after more than 6 years of decomposition. These differences suggest that litter-mediated effects on nutrient dynamics have complex interactions with decomposition over time

Robustness Of Baryon Acoustic Oscillation Constraints For Early-Universe Modifications Of ΛCDM Cosmology

Baryon acoustic oscillations (BAO) provide a robust standard ruler and can be used to constrain the expansion history of the Universe at low redshift. Standard BAO analyses return a model-independent measurement of the expansion rate and the comoving angular diameter distance as a function of redshift, normalized by the sound horizon at radiation drag. However, this methodology relies on anisotropic distance distortions of a fixed, precomputed template (obtained in a given fiducial cosmology) in order to fit the observations. Therefore, it may be possible that extensions to the consensus ΛCDM add contributions to the BAO feature that cannot be captured by the template fitting. We perform mock BAO fits to power spectra computed assuming cosmological models that modify the growth of perturbations prior to recombination in order to test the robustness of the standard BAO analysis. We find no significant bias in the BAO analysis for the models under study (ΛCDM with a free effective number of relativistic species, early dark energy, and a model with interactions between neutrinos and a fraction of the dark matter), even for cases that do not provide a good fit to Planck measurements of the cosmic microwave background power spectra. This result supports the use of the standard BAO analysis and its measurements to perform cosmological parameter inference and to constrain exotic models. In addition, we provide a methodology to reproduce our study for different models and surveys, as well as discuss different options to handle eventual biases in the BAO measurements

Sex-Related Differences in the Association of Fundamental Movement Skills and Health and Behavioral Outcomes in Children

This study aimed to assess whether sex moderates the association of fundamental movement skills (FMS) and health and behavioral outcomes. In 170 children (10.6 ± 0.3 years; 98 girls), path-analysis was used to assess the associations of FMS (Get Skilled, Get Active) with perceived sports competence (Children and Youth - Physical Self-Perception Profile), time spent in vigorous-intensity physical activity (VPA), sedentary time and body mass index (BMI) z-score. For boys, object control skill competence had a direct association with perceived sports competence (β = 0.39; 95% CI: 0.21 to 0.57) and an indirect association with sedentary time, through perceived sports competence (β = -0.19; 95% CI: -0.09 to -0.32). No significant association was observed between FMS and perceived sports competence for girls, although locomotor skills were found to predict VPA (β = 0.18; 95% CI: 0.08 to 0.27). Perceived sports competence was associated with sedentary time, with this stronger for boys (β = -0.48; 95% CI: -0.64 to -0.31), than girls (β = -0.29; 95% CI: -0.39 to -0.19). The study supports a holistic approach to health-related interventions and highlights a key association of perceived sports competence and the time children spend sedentary

Self-Interacting Dark Matter from a Non-Abelian Hidden Sector

There is strong evidence in favor of the idea that dark matter is self interacting, with the cross section-to-mass ratio σ/m∼1  cm^2/g∼1  barn/GeV. We show that viable models of dark matter with this large cross section are straightforwardly realized with non-Abelian hidden sectors. In the simplest of such models, the hidden sector is a pure gauge theory, and the dark matter is composed of hidden glueballs with a mass around 100 MeV. Alternatively, the hidden sector may be a supersymmetric pure gauge theory with a ∼10  TeV gluino thermal relic. In this case, the dark matter is largely composed of glueballinos that strongly self interact through the exchange of light glueballs. We present a unified framework that realizes both of these possibilities in anomaly-mediated supersymmetry breaking, where, depending on a few model parameters, the dark matter may be composed of hidden glueballinos, hidden glueballs, or a mixture of the two. These models provide simple examples of multicomponent dark matter, have interesting implications for particle physics and cosmology, and include cases where a subdominant component of dark matter may be extremely strongly self interacting, with interesting astrophysical consequences

Safeguarding in international development research: evidence review

This evidence review, undertaken in March-April 2019 by a team led by Dr David Orr at the University of Sussex, aims to characterise the nature of safeguarding issues and challenges that may arise in the specific context of international development research, identify existing guidance and review its implementation. This rapid review was guided by two overarching questions: 1.What is known about the prevalence and nature of vulnerability, power imbalances, and safeguarding concerns within international development research? 2.How is safeguarding currently addressed within international development research, what is the evidence on how fit for purpose it is, and what models of good practice can be identified? A draft set of principles and best practice guidance, drawn from the findings of this evidence review, are set out in this 10 page briefing paper

Strongly interacting dark matter: Self-interactions and keV lines

We consider a simple supersymmetric hidden sector: pure SU(N) gauge theory. Dark matter is made up of hidden glueballinos with mass m_X and hidden glueballs with mass near the confinement scale Λ. For m_X ∼ 1 TeV and Λ ∼ 100 MeV, the glueballinos freeze out with the correct relic density and selfinteract through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order Λ^2 = m_X ∼ 10 keV. We show that the radiative decays of the excited state can explain the observed 3.5 keV x-ray line signal from clusters of galaxies, Andromeda, and the Milky Way