6,881 research outputs found

    Interferometric mapping of Magnetic fields: G30.79 FIR 10

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    We present polarization maps of G30.79 FIR 10 (in W43) from thermal dust emission at 1.3 mm and from CO J=212 \to 1 line emission. The observations were obtained using the Berkeley-Illinois-Maryland Association array in the period 2002-2004. The G30.79 FIR 10 region shows an ordered polarization pattern in dust emission, which suggests an hourglass shape for the magnetic field. Only marginal detections for line polarization were made from this region. Application of the Chandrashkar-Fermi method yielded Bpos1.7B_{pos} \approx 1.7 mG and a statistically corrected mass to magnetic flux ratio λC0.9\lambda_{C} \approx 0.9, or essentially critical.Comment: 11 pages, 2 Figures, Published in Ap

    ECONOMICS OF AGRICULTURAL SOIL CARBON SEQUESTRATION IN THE NORTHERN PLAINS

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    Under the Kyoto protocol of the United Nations Framework Convention on Climate Change the United States is charged with reducing emissions of greenhouse gases to seven percent below their 1990 levels by the period 2008-2012. These reductions could be met from many industries including agriculture. In this paper, an economic simulation model is linked to an ecosystem model to quantify the economic efficiency of policies that might be used to sequester carbon (C) in agricultural soils in the Northern Plains region. Simulations with the Century ecosystem model show that long-term soil C levels associated with a crop/fallow system are less than those for grass alone, but that soil C levels for grass-clover-pasture are greater than for continuously cropped grains. The analysis shows that a CRP-style policy is found to be an inefficient means to increase soil C because the per acre payments to convert crop-land to grass-only draw land from both the crop/fallow system and the continuous cropping system, and costs typically exceed 100perMT(metricton)ofC.Incontrast,paymentstoadoptcontinuouscroppingwerefoundtoproduceincreasesinsoilCforbetween100 per MT (metric ton) of C. In contrast, payments to adopt continuous cropping were found to produce increases in soil C for between 5 to $70 depending on area and degree of targeting of the payments. The most efficient, lowest cost policy is achieved when payments are targeted to land that was previously in a crop/fallow rotation. In this range, soil C sequestration appears to be competitive with C sequestered from other sources.policy design, economic efficiency, soil carbon, sequestration, valuing soil carbon, Great Plains agriculture, Resource /Energy Economics and Policy, Q2,

    ECONOMICS OF AGRICULTURAL SOIL CARBON SEQUESTRATION IN THE NORTHERN GREAT PLAINS

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    Under the Kyoto protocol of the United Nations Framework Convention on Climate Change the United States is charged with reducing emissions of greenhouse gases to seven percent below their 1990 levels by the period 2008-2012. These reductions could be met from many industries including agriculture. In this paper, an economic simulation model is linked to the CENTURY ecosystem model to quantify the economic efficiency of policies that might be used to sequester carbon (C) in agricultural soils in the Northern Great Plains region. Model outputs are combined to assess the costs of inducing changes in equilibrium levels of soil C through three types of policies. The first is a CRP-style policy that provides producers with per-acre payments for converting crop-land to permanent grass; the second is a policy that provides per-acre payments to all farmers that use continuous cropping, regardless of the land's cropping history; the third is a policy that provides per-acre payments for the use of continuous cropping only on land units that had previously been in a crop/fallow rotation. The analysis shows that a CRP-style policy is found to be an inefficient means to increase soil C resulting in costs that typically exceed 100perMT(metricton)ofC.Incontrast,paymentstoadoptcontinuouscroppingwerefoundtoproduceincreasesinsoilCforbetween100 per MT (metric ton) of C. In contrast, payments to adopt continuous cropping were found to produce increases in soil C for between 5 to $70/MT depending on the geographic area and degree of targeting of the payments. The most efficient, lowest cost policy is achieved when payments are targeted to land that was previously in a crop/fallow rotation. In this range, soil C sequestration appears to be competitive with C sequestered from other sources.policy design, economic efficiency, soil carbon, sequestration, valuing soil carbon, Great Plains agriculture, Environmental Economics and Policy, Q2,

    Computationally modeling lipid metabolism and aging: A mini-review

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    This is an Version of Record of an article published in Computational and Structural Biotechnology Journal in 15 November 2014, available online: http://dx.doi.org/10.1016/j.csbj.2014.11.006 This is an open-access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/ licenses/by/3.0/One of the greatest challenges in biology is to improve the understanding of the mechanisms which underpin aging and how these affect health. The need to better understand aging is amplified by demographic changes, which have caused a gradual increase in the global population of older people. Aging western populations have resulted in a rise in the prevalence of age-related pathologies. Of these diseases, cardiovascular disease is the most common underlying condition in older people. The dysregulation of lipid metabolism due to aging impinges significantly on cardiovascular health. However, the multifaceted nature of lipid metabolism and the complexities of its interaction with aging make it challenging to understand by conventional means. To address this challenge computational modeling, a key component of the systems biology paradigm is being used to study the dynamics of lipid metabolism. This mini-review briefly outlines the key regulators of lipid metabolism, their dysregulation, and how computational modeling is being used to gain an increased insight into this system

    Cardiovascular disease and healthy ageing

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    Cardiovascular diseases are main cause of morbidity and mortality in the Western World. Cardiovascular disease increases in its prevalence with age and the burden of this condition is set to increase with an Ageing global population. There are many factors that impact cardiovascular disease risk. The aim of this brief commentary is to explore some of these factors; specifically, we will examine the role of social status, nutrition and, psychological stress in modulating cardiovascular disease risk. Our aim is to emphasise the multidimensional nature of this condition and to stress that a more complete understanding of the mechanisms which underpin its pathology can only be achieved by adopting an integrated approach which treats the progression of this disease in a more holistic fashion

    Masses, luminosities and dynamics of galactic molecular clouds

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    Star formation in galaxies takes place in molecular clouds and the Milky Way is the only galaxy in which it is possible to resolve and study the physical properties and star formation activity of individual clouds. The masses, luminosities, dynamics, and distribution of molecular clouds, primarily giant molecular clouds in the Milky Way are described and analyzed. The observational data sets are the Massachusetts-Stony Brook CO Galactic Plane Survey and the IRAS far IR images. The molecular mass and infrared luminosities of glactic clouds are then compared with the molecular mass and infrared luminosities of external galaxies

    Interferometric Mapping of Magnetic fields: NGC2071IR

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    We present polarization maps of NGC2071IR from thermal dust emission at 1.3 mm and from CO J=212 \to 1 line emission. The observations were obtained using the Berkeley-Illinois-Maryland Association array in the period 2002-2004. We detected dust and line polarized emission from NGC2071IR that we used to constrain the morphology of the magnetic field. From CO J=212 \to 1 polarized emission we found evidence for a magnetic field in the powerful bipolar outflow present in this region. We calculated a visual extinction Av26A_{\rm{v}} \approx 26 mag from our dust observations. This result, when compared with early single dish work, seems to show that dust grains emit polarized radiation efficiently at higher densities than previously thought. Mechanical alignment by the outflow is proposed to explain the polarization pattern observed in NGC2071IR, which is consistent with the observed flattening in this source.Comment: 17 pages, 4 Figures, Accepted for publication in Ap

    Accelerating global ocean observing: monitoring the coastal ocean through broadly accessible, low-cost sensor networks

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wang, Z. A., Michel, A. P. M., & Mooney, T. A. Accelerating global ocean observing: monitoring the coastal ocean through broadly accessible, low-cost sensor networks. Marine Technology Society Journal, 55(3), (2021): 82–83, https://doi.org/10.4031/MTSJ.55.3.52.The global coastal ocean provides food and other critical resources to human societies. Yet this habitat, for which many depend, has experienced severe degradation from human activities. The rates of human-induced changes along the coast demand significantly improved coverage of ocean observations in order to support science-based decision making and policy formation tailored to specific regions. Our proposal envisions developing a global network of low-cost, easily produced and readily deployed oceanographic sensors for use on a wide variety of platforms in the coastal ocean. A substantially large number of these sensors can thus be installed on existing infrastructure, ships of opportunity, and fishing fleets, or even individually along the coast, particularly in vulnerable and disadvantaged regions. This would vastly increase the spatiotemporal resolution of the current data coverage along the coast, allowing greater equitable access. It would also offer significant opportunities for partnership with communities, NGOs, governments, and other stakeholders, as well as a wide range of commercial and industrial sectors to develop and deploy sensors in scalable networks transmitting data in near-real time. Finally, it presents a vastly lowered bar for participation by citizen scientists and other engaged members of the public to address location-specific coastal problems anywhere in the world.National Science Foundation; Project Title “Collaborative Research: IDBR: Type A: A High-resolution bio-sensor to simultaneously measure the behavior, vital rates and environment of key marine organisms”; Award Number 1455593 to ZAW and TAM

    Thinking beyond the hybrid:“actually-existing” cities “after neoliberalism” in Boyle <i>et al.</i>

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    In their article, ‘The spatialities of actually existing neoliberalism in Glasgow, 1977 to present’, Mark Boyle, Christopher McWilliams and Gareth Rice (2008) usefully problematise our current understanding of neoliberal urbanism. Our response is aimed at developing a sympathetic but critical approach to Boyle et al's understanding of neoliberal urbanism as illustrated by the Glasgow example. In particular, the counterposing by Boyle et al of a 'hybrid, mutant' model to a 'pure' model of neoliberalism for us misrepresents existing models of neoliberalism as a perfectly finished object rather than a roughly mottled process. That they do not identify any ‘pure’ model leads them to create a straw construct against which they can claim a more sophisticated, refined approach to the messiness of neoliberal urbanism. In contrast, we view neoliberalism as a contested and unstable response to accumulation crises at various scales of analysis

    Mathematical Modelling of Metabolic Regulation in Aging

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    The underlying cellular mechanisms that characterize aging are complex and multifaceted. However, it is emerging that aging could be regulated by two distinct metabolic hubs. These hubs are the pathway defined by the mammalian target of rapamycin (mTOR) and that defined by the NAD+-dependent deacetylase enzyme, SIRT1. Recent experimental evidence suggests that there is crosstalk between these two important pathways; however, the mechanisms underpinning their interaction(s) remains poorly understood. In this review, we propose using computational modelling in tandem with experimentation to delineate the mechanism(s). We briefly discuss the main modelling frameworks that could be used to disentangle this relationship and present a reduced reaction pathway that could be modelled. We conclude by outlining the limitations of computational modelling and by discussing opportunities for future progress in this area
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