Science's immunity to moral refutation

Our moral convictions cannot, on the face of it, count in evidence against scientific claims with which they happen to conflict. Moral anti-realists of whatever stripe can explain this easily: science is immune to moral refutation because moral discourse is defective as a trustworthy source of true and objective judgments. Moral realists, they can add, are unable to explain this immunity. After describing how anti-realists might implement this reasoning, the paper argues that the only plausible realist comeback turns on the practical nature of moral reasoning. This comeback, however, places significant constraints on the structure of evidence for moral judgments. These constraints cannot be met by coherentist defenders of reflective-equilibrium methodology or by anyone sympathetic to bottom-up, case-driven foundationalism, including those who claim we have perceptual or perception-like access to moral truths. Unfortunately for realists in these categories, alternative realism-friendly accounts of science’s apparent moral immunity are unpromising. These neither explain nor explain away our unwillingness to infer an is from an ought, as Hume might have put it. Science’s apparent immunity to moral refutation therefore poses a serious problem for any realist unhappy with top-down, theory-driven conceptions of the structure of moral evidence

Description and performance of track and primary-vertex reconstruction with the CMS tracker

A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10–12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung

Oxidative protein labeling in mass-spectrometry-based proteomics

Oxidation of proteins and peptides is a common phenomenon, and can be employed as a labeling technique for mass-spectrometry-based proteomics. Nonspecific oxidative labeling methods can modify almost any amino acid residue in a protein or only surface-exposed regions. Specific agents may label reactive functional groups in amino acids, primarily cysteine, methionine, tyrosine, and tryptophan. Nonspecific radical intermediates (reactive oxygen, nitrogen, or halogen species) can be produced by chemical, photochemical, electrochemical, or enzymatic methods. More targeted oxidation can be achieved by chemical reagents but also by direct electrochemical oxidation, which opens the way to instrumental labeling methods. Oxidative labeling of amino acids in the context of liquid chromatography(LC)–mass spectrometry (MS) based proteomics allows for differential LC separation, improved MS ionization, and label-specific fragmentation and detection. Oxidation of proteins can create new reactive groups which are useful for secondary, more conventional derivatization reactions with, e.g., fluorescent labels. This review summarizes reactions of oxidizing agents with peptides and proteins, the corresponding methodologies and instrumentation, and the major, innovative applications of oxidative protein labeling described in selected literature from the last decade