2,212 research outputs found

    Benefit-Cost Analysis in Environmental, Health, and Safety Regulation: A Statement of Principles

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    Benefit-cost analysis can play a very important role in legislative and regulatory policy debates on improving the environment, health, and safety. It can help illustrate the tradeoffs that are inherent in public policymaking as well as make those tradeoffs more transparent. It can also help agencies set regulatory priorities. Benefit-cost analysis should be used to help decisionmakers reach a decision. Contrary to the views of some, benefit-cost analysis is neither necessary nor sufficient for designing sensible public policy. If properly done, it can be very helpful to agencies in the decisionmaking process. Decisionmakers should not be precluded from considering the economic benefits and costs of different policies in the development of regulations. Laws that prohibit costs or other factors from being considered in administrative decisionmaking are inimical to good public policy. Currently, several of the most important regulatory statutes have been interpreted to imply such prohibitions. Benefit-cost analysis should be required for all major regulatory decisions, but agency heads should not be bound by a strict benefit-cost test. Instead, they should be required to consider available benefit-cost analyses and to justify the reasons for their decision in the event that the expected costs of a regulation far exceed the expected benefits. Agencies should be encouraged to use economic analysis to help set regulatory priorities. Economic analyses prepared in support of particularly important decisions should be subjected to peer review both inside and outside government. Benefits and costs of proposed major regulations should be quantified wherever possible. Best estimates should be presented along with a description of the uncertainties. Not all benefits or costs can be easily quantified, much less translated into dollar terms. Nevertheless, even qualitative descriptions of the pros and cons associated with a contemplated action can be helpful. Care should be taken to ensure that quantitative factors do not dominate important qualitative factors in decisionmaking. The Office of Management and Budget, or some other coordinating agency, should establish guidelines that agencies should follow in conducting benefit-cost analyses. Those guidelines should specify default values for the discount rate and certain types of benefits and costs, such as the value of a small reduction in mortality risk. In addition, agencies should present their results using a standard format, which summarizes the key results and highlights major uncertainties.

    Is There a Role for Benefit-Cost Analysis in Environmental, Health, and Safety Regulation?

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    Benefit-cost analysis has a potentially important role to play in helping inform regulatory decision-making, although it should not be the sole basis for such decision-making. This paper offers eight principles on the appropriate use of benefit-cost analysis.Environment, Health and Safety, Regulatory Reform

    Epigenetics as a mechanism driving polygenic clinical drug resistance

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    Aberrant methylation of CpG islands located at or near gene promoters is associated with inactivation of gene expression during tumour development. It is increasingly recognised that such epimutations may occur at a much higher frequency than gene mutation and therefore have a greater impact on selection of subpopulations of cells during tumour progression or acquisition of resistance to anticancer drugs. Although laboratory-based models of acquired resistance to anticancer agents tend to focus on specific genes or biochemical pathways, such 'one gene : one outcome' models may be an oversimplification of acquired resistance to treatment of cancer patients. Instead, clinical drug resistance may be due to changes in expression of a large number of genes that have a cumulative impact on chemosensitivity. Aberrant CpG island methylation of multiple genes occurring in a nonrandom manner during tumour development and during the acquisition of drug resistance provides a mechanism whereby expression of multiple genes could be affected simultaneously resulting in polygenic clinical drug resistance. If simultaneous epigenetic regulation of multiple genes is indeed a major driving force behind acquired resistance of patients' tumour to anticancer agents, this has important implications for biomarker studies of clinical outcome following chemotherapy and for clinical approaches designed to circumvent or modulate drug resistance

    Potential diagnostic and prognostic values of detecting promoter hypermethylation in the serum of patients with gastric cancer

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    While there is no reliable serum biomarker for the diagnosis and monitoring of patients with gastric cancer, we tested the potential diagnostic and prognostic values of detecting methylation changes in the serum of gastric cancer patients. DNA was extracted from the pretherapeutic serum of 60 patients with confirmed gastric adenocarcinoma and 22 age-matched noncancer controls. Promoter hypermethylation in 10 tumour-related genes (APC, E-cadherin, GSTP1, hMLH1, MGMT, p15, p16, SOCS1, TIMP3 and TGF-beta RII) was determined by quantitative methylation-specific PCR (MethyLight). Preferential methylation in the serum DNA of gastric cancer patients was noted in APC (17%), E-cadherin (13%), hMLH1 (41%) and TIMP3 (17%) genes. Moreover, patients with stages III/IV diseases tended to have higher concentrations of methylated APC (P=0.08), TIMP3 (P=0.005) and hMLH1 (P=0.03) in the serum. In all, 33 cancers (55%) had methylation detected in the serum in at least one of these four markers, while three normal subjects had methylation detected in the serum (specificity 86%). The combined use of APC and E-cadherin methylation markers identified a subgroup of cancer patients with worse prognosis (median survival 3.3 vs 16.1 months, P=0.006). These results suggest that the detection of DNA methylation in the serum may carry both diagnostic and therapeutic values in gastric cancer patients

    Search for Zgamma events with large missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV

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    We present the first search for supersymmetry (SUSY) in Zgamma final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb-1 collected with the D0 experiment in ppbar collisions at sqrt(s)=1.96 TeV. This signature is predicted in gauge-mediated SUSY-breaking models, where the lightest neutralino is the next-to-lightest supersymmetric particle (NLSP) and is produced in pairs, possibly through decay from heavier supersymmetric particles. The NLSP can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for SUSY breaking scales of Lambda < 87 TeV, corresponding to neutralino masses of < 151 GeV.Comment: submitted to Phys. Rev. Let

    Search for B0π0π0B^{0}\to \pi^{0}\pi^{0} Decay

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    We have searched for the charmless hadronic decay of B0 mesons into two neutral pions. Using 9.13fb^-1 taken at the Upsilon(4S) with the CLEO detector, we obtain an improved upper limit for the branching fraction BR(B0-->pi0pi0) < 5.7*10^-6 at the 90% confidence level.Comment: pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

    Direct measurement of the mass difference between top and antitop quarks

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    We present a direct measurement of the mass difference between top and antitop quarks (dm) in lepton+jets top-antitop final states using the "matrix element" method. The purity of the lepton+jets sample is enhanced for top-antitop events by identifying at least one of the jet as originating from a b quark. The analyzed data correspond to 3.6 fb-1 of proton-antiproton collisions at 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron Collider. The combination of the e+jets and mu+jets channels yields dm = 0.8 +/- 1.8 (stat) +/- 0.5 (syst) GeV, which is in agreement with the standard model expectation of no mass difference.Comment: submitted to Phys. Rev.

    A search for charged massive long-lived particles

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    We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb1^{-1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron ppˉp\bar{p} collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx)(dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.Comment: submitted to Phys. Rev. Letter

    Precise measurement of the top quark mass in the dilepton channel at D0

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    We measure the top quark mass (mt) in ppbar collisions at a center of mass energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events, where l denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat) +- 2.4(syst) GeV, which is in agreement with the current world average mt = 173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the dilepton channel.Comment: 7 pages, 4 figure
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