34 research outputs found

    The α/β hydrolase fold

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    We have identified a new protein fold-the α/β hydrolase fold-that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an α/β sheet, not barrel, of eight β-sheets connected by α-helices. These enzymes have diverged from a common ancestor so as to preserve the arrangement of the catalytic residues, not the binding site. They all have a catalytic triad, the elements of which are borne on loops which are the best-conserved structural features in the fold. Only the histidine in the nucleophile-histidine-acid catalytic triad is completely conserved, with the nucleophile and acid loops accommodating more than one type of amino acid. The unique topological and sequence arrangement of the triad residues produces a catalytic triad which is, in a sense, a mirror-image of the serine protease catalytic triad. There are now four groups of enzymes which contain catalytic triads and which are related by convergent evolution towards a stable, useful active site: the eukaryotic serine proteases, the cysteine proteases, subtilisins and the α/β hydrolase fold enzymes

    Gemcitabine Plus Bevacizumab Compared With Gemcitabine Plus Placebo in Patients With Advanced Pancreatic Cancer: Phase III Trial of the Cancer and Leukemia Group B (CALGB 80303)

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    The combination of gemcitabine plus bevacizumab produced a 21% response rate and a median survival of 8.8 months in a multicenter phase II trial in patients with metastatic pancreatic cancer. These encouraging data led Cancer and Leukemia Group B (CALGB) to conduct a double-blind, placebo-controlled, randomized phase III trial of gemcitabine/bevacizumab versus gemcitabine/placebo in advanced pancreatic cancer patients

    First Impressions Matter: A Model Of Confirmatory Bias

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    Psychological research indicates that people have a cognitive bias that leads them to misinterpret new information as supporting previously held hypotheses. We show in a simple model that such confirmatory bias induces overconfidence: given any probabilistic assessment by an agent that one of two hypotheses is true, the appropriate beliefs would deem it less likely to be true. Indeed, the hypothesis that the agent believes in may be more likely to be wrong than right. We also show that the agent may come to believe with near certainty in a false hypothesis despite receiving an infinite amount of information. © 2000 the President and Fellows of Harvard College and the Massachusetts Institute of Technology

    Managerial Judges: An Economic Analysis of the Judicial Management of Legal Discovery

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    I analyze the effect of procedural rules that permit judges to limit pretrial discovery. In the presence of asymmetric information, a litigant may forgo settlement before discovery if his opponent interprets a serious offer as a sign that her discovery is likely to uncover useful evidence, leading her to invest more in discovery. Furthermore, a litigant may forgo settlement in order to strengthen his or her threat of future discovery. I show that by limiting pretrial discovery, the judge can simultaneously increase the probability of early settlement and reduce expected litigation costs, without reducing potential injurers' incentives to take care.

    The α/β hydrolase fold

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    We have identified a new protein fold-the α/β hydrolase fold-that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an α/β sheet, not barrel, of eight β-sheets connected by α-helices. These enzymes have diverged from a common ancestor so as to preserve the arrangement of the catalytic residues, not the binding site. They all have a catalytic triad, the elements of which are borne on loops which are the best-conserved structural features in the fold. Only the histidine in the nucleophile-histidine-acid catalytic triad is completely conserved, with the nucleophile and acid loops accommodating more than one type of amino acid. The unique topological and sequence arrangement of the triad residues produces a catalytic triad which is, in a sense, a mirror-image of the serine protease catalytic triad. There are now four groups of enzymes which contain catalytic triads and which are related by convergent evolution towards a stable, useful active site: the eukaryotic serine proteases, the cysteine proteases, subtilisins and the α/β hydrolase fold enzymes.

    Adversarial versus Inquisitorial Testimony

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    An arbiter can decide a case on the basis of his priors, or the two parties to the conflict may present further evidence. The parties may misrepresent evidence in their favor at a cost. At equilibrium the two parties never testify together. When the evidence is much in favor of one party, this party testifies. When the evidence is close to the prior mean, no party testifies. We compare this outcome under a purely adversarial procedure with the outcome under a purely inquisitorial procedure (Emons and Fluet 2009). We provide sufficient conditions on when one procedure is better than the other one
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