2,585 research outputs found

    A Federal Renewable Electricity Requirement

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    Rising energy prices and climate change have changed both the economics and politics of electricity. In response, over half the states have enacted "renewable portfolio standards" (RPS) that require utilities to obtain some power from "renewable" generation resources rather than carbon emitting fossil fuels. Reports of state-level success have brought proposals for a national standard. Like several predecessor Congresses, however, the most recent one failed to pass RPS legislation. Before trying one more time, legislators should ask why they favor a policy so politically correct and so economically suspect. Support for a national program largely stems from misleading claims about state-level successes, misunderstandings about how renewables interact with other environmental regulation, and misinformation about the actual benefits renewables create. State RPS programs are largely in disarray, and even the apparently successful ones have had little impact. California's supposedly aggressive program has left it with the same percentage of renewable power as in 1998, and Texas's seemingly impressive wind turbine investments produce only two percent of its electricity. The public may envision solar collectors but wind accounts for almost all of the growth in renewable power, and it largely survives on favorable tax treatment. Wind's intermittency reduces its efficacy in carbon control because it requires extra conventional generation reserves. Computer-generated predictions about a national RPS are generally unreliable, but they show that with or without one the great majority of generation investments for the next several decades will be fossil-fueled. Even without the technological and environmental shortcomings of renewables, the case for a national RPS is economically flawed. Emissions policies are moving toward efficient market-based trading systems and more rational setting of standards. A national RPS clashes with principles of efficient environmental policy because it is a technological requirement that applies to a single industry. Arguments that a national RPS will create jobs, mitigate energy price risks, improve national security and make the United Sates more competitive internationally are in the main restatements of elementary economic fallacies. It is hard to imagine a program that delivers as little in theory as a national RPS, and the experiences of the states indicate that it delivers equally little in practice

    Receptor-mediated gene delivery into mammalian cells

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    The cerebrospinal fluid proteome in HIV infection: change associated with disease severity

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    <p>Abstract</p> <p>Background</p> <p>Central nervous system (CNS) infection is a nearly universal feature of untreated systemic HIV infection with a clinical spectrum that ranges from chronic asymptomatic infection to severe cognitive and motor dysfunction. Analysis of cerebrospinal fluid (CSF) has played an important part in defining the character of this evolving infection and response to treatment. To further characterize CNS HIV infection and its effects, we applied advanced high-throughput proteomic methods to CSF to identify novel proteins and their changes with disease progression and treatment.</p> <p>Results</p> <p>After establishing an <it>accurate mass and time </it>(AMT) tag database containing 23,141 AMT tags for CSF peptides, we analyzed 91 CSF samples by LC-MS from 12 HIV-uninfected and 14 HIV-infected subjects studied in the context of initiation of antiretroviral therapy and correlated abundances of identified proteins a) within and between subjects, b) with all other proteins across the entire sample set, and c) with "external" CSF biomarkers of infection (HIV RNA), immune activation (neopterin) and neural injury (neurofilament light chain protein, NFL). We identified a mean of 2,333 +/- 328 (SD) peptides covering 307 +/-16 proteins in the 91 CSF sample set. Protein abundances differed both between and within subjects sampled at different time points and readily separated those with and without HIV infection. Proteins also showed inter-correlations across the sample set that were associated with biologically relevant dynamic processes. One-hundred and fifty proteins showed correlations with the external biomarkers. For example, using a threshold of cross correlation coefficient (Pearson's) ≤ -0.3 and ≥0.3 for potentially meaningful relationships, a total of 99 proteins correlated with CSF neopterin (43 negative and 56 positive correlations) and related principally to neuronal plasticity and survival and to innate immunity. Pathway analysis defined several networks connecting the identified proteins, including one with amyloid precursor protein as a central node.</p> <p>Conclusions</p> <p>Advanced CSF proteomic analysis enabled the identification of an array of novel protein changes across the spectrum of CNS HIV infection and disease. This initial analysis clearly demonstrated the value of contemporary state-of-the-art proteomic CSF analysis as a discovery tool in HIV infection with likely similar application to other neurological inflammatory and degenerative diseases.</p

    Heme Oxygenase-1 Accelerates Cutaneous Wound Healing in Mice

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    Heme oxygenase-1 (HO-1), a cytoprotective, pro-angiogenic and anti-inflammatory enzyme, is strongly induced in injured tissues. Our aim was to clarify its role in cutaneous wound healing. In wild type mice, maximal expression of HO-1 in the skin was observed on the 2nd and 3rd days after wounding. Inhibition of HO-1 by tin protoporphyrin-IX resulted in retardation of wound closure. Healing was also delayed in HO-1 deficient mice, where lack of HO-1 could lead to complete suppression of reepithelialization and to formation of extensive skin lesions, accompanied by impaired neovascularization. Experiments performed in transgenic mice bearing HO-1 under control of keratin 14 promoter showed that increased level of HO-1 in keratinocytes is enough to improve the neovascularization and hasten the closure of wounds. Importantly, induction of HO-1 in wounded skin was relatively weak and delayed in diabetic (db/db) mice, in which also angiogenesis and wound closure were impaired. In such animals local delivery of HO-1 transgene using adenoviral vectors accelerated the wound healing and increased the vascularization. In summary, induction of HO-1 is necessary for efficient wound closure and neovascularization. Impaired wound healing in diabetic mice may be associated with delayed HO-1 upregulation and can be improved by HO-1 gene transfer

    A Phylogenetic Analysis of the African Plant Genus Palisota (family Commelinaceae) based on Chloroplast DNA Sequences

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    The plant genus Palisota (family Commelinaceae, or spiderwort family) consists of approximately 20 species and is distributed throughout the forests of tropical Africa. The genus exhibits several unusual morphological characteristics, and as a result has been difficult to classify based on morphology. Molecular phylogenetic studies have placed it near the base of Commelinaceae, but the exact placement of Palisota within the family is not clear. As the African continent has become more arid in recent geological times, the forests have receded, reducing the habitat for Palisota species and potentially impacting speciation and extinction rates within the genus. The goal of this study is to sequence the chloroplast-encoded gene rbcL in several additional species of Palisota and its relatives in order to: 1) determine the phylogenetic relationship of the genus with respect to other members of Commelinaceae; 2) evaluate phylogenentic relationships among species of Palisota; and 3) infer relative speciation/extinction rates within the genus. Additionally, we are exploring the use of other molecular regions for phylogenetic analysis with the genus

    Independent Component Analysis for Improved Defect Detection in Guided Wave Monitoring

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    Guided wave sensors are widely used in a number of industries and have found particular application in the oil and gas industry for the inspection of pipework. Traditionally this type of sensor was used for one-off inspections, but in recent years there has been a move towards permanent installation of the sensor. This has enabled highly repeatable readings of the same section of pipe, potentially allowing improvements in defect detection and classification. This paper proposes a novel approach using independent component analysis to decompose repeat guided wave signals into constituent independent components. This separates the defect from coherent noise caused by changing environmental conditions, improving detectability. This paper demonstrates independent component analysis applied to guided wave signals from a range of industrial inspection scenarios. The analysis is performed on test data from pipe loops that have been subject to multiple temperature cycles both in undamaged and damaged states. In addition to processing data from experimental damaged conditions, simulated damage signals have been added to “undamaged” experimental data, so enabling multiple different damage scenarios to be investigated. The algorithm has also been used to process guided wave signals from finite element simulations of a pipe with distributed shallow general corrosion, within which there is a patch of severe corrosion. In all these scenarios, the independent component analysis algorithm was able to extract the defect signal, rejecting coherent noise

    Don't Increase Federal Gasoline Taxes - Abolish Them

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    Many experts believe that gasoline taxes should be increased for a variety of reasons. Their arguments are unpersuasive. Oil is not disappearing, and when it becomes more expensive, market agents will substitute away from gasoline to save money. The link between oil price shocks and recessions, although real in the 1970s, has been much more benign since 1985 because of the termination of price controls. Market actors properly account for energy costs in their purchasing decisions absent government intervention. Pollution taxes, congestion fees, and automobile insurance premiums more closely related to vehicle miles traveled are better remedies for the externalities associated with automobile travel than a simple fuel tax. Gasoline consumption does not necessarily distort American foreign policy, impose military commitments, or empower Islamic terrorist organizations. State and federal gasoline taxes should be abolished. Local governments should tax gasoline only to the extent necessary to pay for roads when user charges are not feasible. If government feels compelled to more aggressively regulate vehicle tailpipe emissions or access to public roadways, pollution taxes and road user fees are better means of doing so than fuel taxes. Regardless, perfectly internalizing motor vehicle externalities would likely make the economy less efficient -- not more -- by inducing motorists into even more (economically) inefficient mass transit use. The arguments advanced against increasing gasoline taxes are applicable to the broader discussion about America's reliance on oil generally. The case for policies designed to discourage oil consumption is nearly as threadbare as the case for increasing the gasoline tax -- and for largely the same reasons
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