The equation of state of neutron star matter and the symmetry energy

We present an overview of microscopical calculations of the Equation of State (EOS) of neutron matter performed using Quantum Monte Carlo techniques. We focus to the role of the model of the three-neutron force in the high-density part of the EOS up to a few times the saturation density. We also discuss the interplay between the symmetry energy and the neutron star mass-radius relation. The combination of theoretical models of the EOS with recent neutron stars observations permits us to constrain the value of the symmetry energy and its slope. We show that astrophysical observations are starting to provide important insights into the properties of neutron star matter.Comment: 7 pages, 3 figure, talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS

Respiratory symptoms and cross-shift lung function in relation to cotton dust and endotoxin exposure in textile workers in Nepal: a cross-sectional study

Objectives: Inhalation of a cotton-based particulates has previously been associated with respiratory symptoms and impaired lung function. This study investigates the respiratory health of Nepalese textile workers in relation to dust and endotoxin exposure. Methods: A total of 938 individuals from four sectors (garment, carpet, weaving and recycling) of the textile industry in Kathmandu, Nepal completed a health questionnaire and performed spirometry. A subset (n=384) performed cross-shift spirometry. Personal exposure to inhalable dust and airborne endotoxin was measured during a full shift for 114 workers. Results: The overall prevalence of persistent cough, persistent phlegm, wheeze ever, breathlessness ever and chest tightness ever was 8.5%, 12.5%, 3.2%, 6.5% and 12.3%, respectively. Symptoms were most common among recyclers and least common among garment workers. Exposure to inhalable dust significantly predicted persistent cough and chest tightness. Exposure to endotoxin did not have any independent predictive effect. Significant cross-shift reduction in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were found (p<0.001 for both) being largest for FEV1 in the recyclers (−143 mL), and least in the garment workers (−38 mL; p=0.012). Exposure to inhalable dust predicted a cross-shift reduction in FEV1. Conclusions: This study is the first to investigate the respiratory health of Nepalese cotton workers. The measured association between inhalable dust exposure and reporting of respiratory symptoms and across-shift decrement in FEV1 and FVC indicates that improved dust control measures should be instituted, particularly in the recycling and carpet sectors. The possible role of other biologically active agents of cotton dust beyond endotoxin should be further explored

Charcoal (Biochar) as soil conditioner to enhance fertilizers and water use efficiency in agriculture in acid tropical soils in the Central Amazon Basin

This article summarize result of many experiments conducted in 15 years of research with biochar in nursery and field experiments in the Central Amazon

Influence of Vertical Heterogeneities in the Canopy Microenvironment on Interannual Variability of Carbon Uptake in Temperate Deciduous Forests

Vegetation structure and function are key design choices in terrestrial models that affect the relationship between carbon uptake and environmental drivers. Here, we investigate how representing canopy vertical structure in a terrestrial biosphere model- that is, micrometeorological, leaf area, and leaf water profiles- influences carbon uptake at five U.S. temperate deciduous forest sites in July. Specifically, we test whether the interannual variability (IAV) of gross primary productivity (GPP) responds differently to four abiotic environmental drivers- air temperature, relative humidity, incoming shortwave radiation, and soil moisture- using either a Community Land Model multilayer canopy model (CLM- ml) or a big- leaf model (CLM4.5/CLM5). We conclude that vertical leaf area and microclimatic profiles (temperature, humidity, and wind) do not impact GPP IAV compared to a single- layer model when plant hydraulics is excluded. However, with a mechanistic representation of plant hydraulics there is vertically varying water stress in CLM- ml, and the sensitivity of carbon uptake to particular climate variables changes with height, resulting in dampened canopy- scale GPP IAV relative to CLM4.5. Dampening is due to both a reduced dependence on soil moisture and opposing climatic forcing on different leaf layers. Such dampening is not evident in the single- layer representation of plant hydraulic water stress implemented in the recently released CLM5. Overall, both model representations of the canopy fail to accurately simulate observed GPP IAV and this may be related by their inability to capture the upper range of observed hourly GPP and diffuse light- GPP relationships that cannot be resolved by canopy structure alone.Key PointsExplicitly simulated leaf area and microclimatic profiles do not affect gross primary productivity (GPP) interannual variability compared to a - big- leaf- simplificationMultilayer plant hydraulics lead to vertically varying water stress, altering leaf- layer responses to interannual climate variationsAll model simulations underestimate hourly GPP compared to FLUXNET estimates, adversely impacting simulated GPP interannual variabilityPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156484/2/jgrg21710_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156484/1/jgrg21710.pd