11,239 research outputs found
Discussant\u27s response to auditor independence: Its historical development and some proposals for research
https://egrove.olemiss.edu/dl_proceedings/1060/thumbnail.jp
The Impact of Trade Barriers on Mandated Biofuel Consumption in Canada
In 2008 the Canadian government passed amendments to the Environmental Protection Act requiring five percent ethanol in transportation fuels sold in Canada by 2010 and two percent renewable content in diesel and heating fuels by 2012. Agricultural commodity and other groups have lobbied for further marketplace intervention that would ensure the biofuel needed to meet the legislated requirement be produced from domestic sources. Indeed, many of these special interests would like the biofuels content increased from five to ten percent and for the increase to be met by domestic firms only. The objective of this study is to compare the relative economic impacts in Canada of achieving a ten percent biofuel content either through increased imports or by substituting domestic production in place of increased imports.biofuel trade policy ethanol canada, Demand and Price Analysis, International Relations/Trade,
The Impact of Trade Barriers on Mandated Biofuel Consumption in Canada
biofuel ethanol trade Canada, Agricultural and Food Policy, Demand and Price Analysis, International Relations/Trade,
Diffuse-interface model for nanopatterning induced by self-sustained ion etch masking
We construct a simple phenomenological diffuse-interface model for
composition-induced nanopatterning during ion sputtering of alloys. In
simulations, this model reproduces without difficulties the high-aspect ratio
structures and tilted pillars observed in experiments. We investigate the time
evolution of the pillar height, both by simulations and by {\it in situ}
ellipsometry. The analysis of the simulation results yields a good
understanding of the transitions between different growth regimes and supports
the role of segregation in the pattern-formation process.Comment: 10 pages, 3 figures; minor revisions with respect to first version;
figures nicened; journal ref. adde
Preoperative liver registration for augmented monocular laparoscopy using backward–forward biomechanical simulation
PURPOSE: Augmented reality for monocular laparoscopy from a preoperative volume such as CT is achieved in two steps. The first step is to segment the organ in the preoperative volume and reconstruct its 3D model. The second step is to register the preoperative 3D model to an initial intraoperative laparoscopy image. To date, there does not exist an automatic initial registration method to solve the second step for the liver in the de facto operating room conditions of monocular laparoscopy. Existing methods attempt to solve for both deformation and pose simultaneously, leading to nonconvex problems with no optimal solution algorithms. METHODS: We propose in contrast to break the problem down into two parts, solving for (i) deformation and (ii) pose. Part (i) simulates biomechanical deformations from the preoperative to the intraoperative state to predict the liver’s unknown intraoperative shape by modeling gravity, the abdominopelvic cavity’s pressure and boundary conditions. Part (ii) rigidly registers the simulated shape to the laparoscopy image using contour cues. RESULTS: Our formulation leads to a well-posed problem, contrary to existing methods. This is because it exploits strong environment priors to complement the weak laparoscopic visual cues. CONCLUSION: Quantitative results with in silico and phantom experiments and qualitative results with laparosurgery images for two patients show that our method outperforms the state-of-the-art in accuracy and registration time
Stopping power of hot QCD plasma
The partonic energy loss has been calculated taking both the hard and soft
contributions for all the processes, revealing the importance of the
individual channels. Cancellation of the intermediate separation scale has been
exhibited. Subtleties related to the identical final state partons have
properly been taken into account. The estimated collisional loss is compared
with its radiative counter part. We show that there exists a critical energy
() below which the collisional loss is more than its radiative
counterpart. In addition, we present closed form formulas for both the
collision probabilities and the stopping power ()Comment: revised version, section added, 9pages with 5 figure
Dual Deletion of the Sirtuins SIRT2 and SIRT3 Impacts on Metabolism and Inflammatory Responses of Macrophages and Protects From Endotoxemia.
Sirtuin 2 (SIRT2) and SIRT3 are cytoplasmic and mitochondrial NAD-dependent deacetylases. SIRT2 and SIRT3 target proteins involved in metabolic, proliferation and inflammation pathways and have been implicated in the pathogenesis of neurodegenerative, metabolic and oncologic disorders. Both pro- and anti-inflammatory effects have been attributed to SIRT2 and SIRT3, and single deficiency in SIRT2 or SIRT3 had minor or no impact on antimicrobial innate immune responses. Here, we generated a SIRT2/3 double deficient mouse line to study the interactions between SIRT2 and SIRT3. SIRT2/3 <sup>-/-</sup> mice developed normally and showed subtle alterations of immune cell populations in the bone marrow, thymus, spleen, blood and peritoneal cavity that contained notably more anti-inflammatory B-1a cells and less NK cells. In vitro, SIRT2/3 <sup>-/-</sup> macrophages favored fatty acid oxidation (FAO) over glycolysis and produced increased levels of both proinflammatory and anti-inflammatory cytokines. In line with metabolic adaptation and increased numbers of peritoneal B-1a cells, SIRT2/3 <sup>-/-</sup> mice were robustly protected from endotoxemia. Yet, SIRT2/3 double deficiency did not modify endotoxin tolerance. Overall, these data suggest that sirtuins can act in concert or compensate each other for certain immune functions, a parameter to be considered for drug development. Moreover, inhibitors targeting multiple sirtuins developed for clinical purposes may be useful to treat inflammatory diseases
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