1,788 research outputs found

    Bodily attractiveness and egalitarianism are negatively related in males.

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    Ancestrally, relatively attractive individuals and relatively formidable males may have had reduced incentives to be egalitarian (i.e., to act in accordance with norms promoting social equality). If selection calibrated one's egalitarianism to one's attractiveness/formidability, then such people may exhibit reduced egalitarianism ("observed egalitarianism") and be perceived by others as less egalitarian ("perceived egalitarianism") in modern environments. To investigate, we created 3D body models of 125 participants to use both as a source of anthropometric measurements and as stimuli to obtain ratings of bodily attractiveness and perceived egalitarianism. We also measured observed egalitarianism (via an economic "dictator" game) and indices of political egalitarianism (preference for socialism over capitalism) and "equity sensitivity." Results indicated higher egalitarianism levels in women than in men, and moderate-to-strong negative relationships between (a) attractiveness and observed egalitarianism among men, (b) attractiveness and perceived egalitarianism among both sexes, and (c) formidability and perceived egalitarianism among men. We did not find support for two previously-reported findings: that observed egalitarianism and formidability are negatively related in men, and that wealth and formidability interact to explain variance in male egalitarianism. However, this lack of support may have been due to differences in variable measurement between our study and previous studies

    The Responses of Soil and Rhizosphere Respiration to Simulated Climatic Changes Vary by Season.

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    Responses of soil respiration (Rs) to anthropogenic climate change will affect terrestrial carbon storage and, thus, feed back to warming. To provide insight into how warming and changes in precipitation regimes affect the rate and temperature sensitivity of Rs and rhizosphere respiration (Rr) across the year, we subjected a New England old-field ecosystem to four levels of warming and three levels of precipitation (ambient, drought, and wet treatments). We measured Rs and heterotrophic respiration (Rh) monthly (in areas of the plots with and without plants, respectively) and estimated Rr by calculating the difference in respiration between Rs and Rh. Even in this mesic ecosystem, Rs and Rr responded strongly to the precipitation treatments. Drought reduced Rs and Rr, both annually and during the growing season. Annual cumulative Rs responded nonlinearly to precipitation treatments; both drought and supplemental precipitation suppressed Rs compared to the ambient treatment. Warming increased Rs and Rr in spring and winter when soil moisture was optimal but decreased these rates in summer when moisture was limiting. Cumulative winter Rr increased by about 200% in the high warming (approximately 3.5 degrees C) treatment. The effect of climate treatments on the temperature sensitivity of Rs depended on the season. In the fall, the drought treatment decreased apparent Q10 relative to the other precipitation treatments. The responses of Rs to warming and altered precipitation were largely driven by changes in Rr. We emphasize the importance of incorporating realistic soil moisture responses into simulations of soil carbon fluxes; the long-term effects of warming on carbon--climate feedback will depend on future precipitation regimes. Our results highlight the nonlinear responses of soil respiration to soil moisture and, to our knowledge, quantify for the first time the loss of carbon through winter rhizosphere respiration due to warming. While this additional loss is small relative to the cumulative annual flux in this system, such increases in rhizosphere respiration during the non-growing season could have greater consequences in ecosystems where they offset or reduce subsequent warming-induced gains in plant growth

    A Mathematical Origami Puzzle

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    The recent axiomization of Origami has led to numerous breakthroughs in both mathematics and in understanding of the ancient art of paper folding. We propose a puzzle whose solution demonstrates the power of mathematical origami. This puzzle is accessible to the geometry student and could be used as supplemental geometry instruction as an extension of traditional compass and straight edge constructions. Detailed images and photos are provided to guide the audience through the puzzle’s solution

    HOUSEHOLDS' EXPERIENCES WITH THE RED IMPORTED FIRE ANT IN SOUTH CAROLINA

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    The red imported fire ant (Solenopsis invicta), abbreviated as RIFA, is believed to have been brought by accident to Mobile, Alabama in the 1930s via ship ballast from South America. The RIFA was first reported in Charleston and Orangeburg counties in South Carolina in 1952 and has since spread to all 46 counties in the state. The RIFA has had adverse impacts on the environments it has infested. In natural environments, the young of ground-nesting insects, reptiles, birds and mammals are subject to RIFA predation. In agriculture, the RIFA damages crops and livestock. The RIFA poses a health threat to humans, as it is aggressive and has a venomous sting. To learn more about the current impacts of the RIFA, a random sample of South Carolina households was conducted between November 1998 and January 1999. This report summarizes the survey results.Environmental Economics and Policy,

    Effects of Warming and Altered Precipitation on Plant and Nutrient Dynamics of a New England Salt Marsh.

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    Salt marsh structure and function, and consequently ability to support a range of species and to provide ecosystem services, may be affected by climate change. To better understand how salt marshes will respond to warming and associated shifts in precipitation, we conducted a manipulative experiment in a tidal salt marsh in Massachusetts, USA. We exposed two plant communities (one dominated by Spartina patens–Distichlis spicata and one dominated by short form Spartina alterniflora) to five climate manipulations: warming via passive open-topped chambers, doubled precipitation, warming and doubled precipitation, extreme drought via rainout shelter, and ambient conditions. Modest daytime warming increased total aboveground biomass of the S. alterniflora community (24%), but not the S. patens–D. spicata community. Warming also increased maximum stem heights of S. alterniflora (8%), S. patens (8%), and D. spicata (15%). Decomposition was marginally accelerated by warming in the S. alterniflora community. Drought markedly increased total biomass of the S. alterniflora community (53%) and live S. patens (69%), perhaps by alleviating waterlogging of sediments. Decomposition was accelerated by increased precipitation and slowed by drought, particularly in the S. patens–D. spicata community. Flowering phenology responded minimally to the treatments, and pore water salinity, sulfide, ammonium, and phosphate concentrations showed no treatment effects in either plant community. Our results suggest that these salt marsh communities may be resilient to modest amounts of warming and large changes in precipitation. If production increases under climate change, marshes will have a greater ability to keep pace with sea-level rise, although an increase in decomposition could offset this. As long as marshes are not inundated by flooding due to sea-level rise, increases in aboveground biomass and stem heights suggest that marshes may continue to export carbon and nutrients to coastal waters and may be able to increase their carbon storage capability by increasing plant growth under future climate conditions

    gesttools: General Purpose G-Estimation in R

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    In this paper we present gesttools, a series of general purpose, user friendly functions with which to perform g-estimation of structural nested mean models (SNMMs) for time-varying exposures and outcomes in R. The package implements the g-estimation methods found in Vansteelandt and Sjolander (2016) and Dukes and Vansteelandt (2018), and is capable of analysing both end of study and time-varying outcome data that are either binary or continuous, or exposure variables that are either binary, continuous, or categorical. It also allows for the fitting of SNMMs with time-varying causal effects, effect modification by other variables, or both, as well as support for censored data using inverse weighting. We outline the theory underpinning these methods, as well as describing the SNMMs that can be fitted by the software. The package is demonstrated using simulated, and real-world inspired datasets

    Leaf-Level Gas Exchange and Foliar Chemistry of Common Old-Field Species Responding to Warming and Precipitation Treatments.

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    We investigated the shifts in plant carbon (C) and water dynamics by measuring rates of photosynthesis, transpiration, and instantaneous water use efficiency (WUE) in three common species of “old-field” plants—two C3 forb species (Plantago lanceolata and Taraxacum officinale) and one C3 grass species (Elymus repens)—under 12 experimentally altered temperature and precipitation regimes at the Boston Area Climate Experiment (BACE) in Waltham, Massachusetts. We also measured shifts in foliar C and nitrogen (N) content to determine possible changes in plant C/nutrient balance. We hypothesized that the warming treatment would cause an increase in photosynthesis rates, unless water was limiting; therefore, we expected an interactive effect of warming and precipitation treatments. We found that warming and drought reduced leaf-level photosynthesis most dramatically when environmental or seasonal conditions produced soils that were already dry. In general, the plants transpired fastest when soils were wet and slowest when soils were dry. Drought treatments increased WUE relative to plants in the ambient and wet treatments but only during the driest and warmest background conditions. Leaf N concentration increased with warming, thereby indicating that future warming may cause some plants to take up more soil N and/or allocate more N to their leaves, possibly as consequences of increased nutrient availability. There were no significant interactive effects of the warming and precipitation treatments together across all seasons, indicating that responses were not synergistic or ameliorative
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