The Pyrococcus furiosus ironome is dominated by [Fe4S4]2+ clusters or thioferrate-like iron depending on the availability of elemental sulfur.

Pyrococcus furiosus is a hyperthermophilic anaerobic archaeon whose metabolism depends on whether elemental sulfur is (+S0) or is not (-S0) included in growth medium. Under +S0 conditions, expression of respiratory hydrogenase declines while respiratory membrane-bound sulfane reductase and the putative iron-storage protein IssA increase. Our objective was to investigate the iron content of WT and ΔIssA cells under these growth conditions using Mössbauer spectroscopy. WT-S0 cells contained ∼1 mM Fe, with ∼85% present as two spectroscopically distinct forms of S = 0 [Fe4S4]2+ clusters; the remainder was mainly high-spin FeII. WT+S0 cells contained 5 to 9 mM Fe, with 75 to 90% present as magnetically ordered thioferrate-like (TFL) iron nanoparticles. TFL iron was similar to chemically defined thioferrates; both consisted of FeIII ions coordinated by an S4 environment, and both exhibited strong coupling between particles causing high applied fields to have little spectral effect. At high temperatures with magnetic hyperfine interactions abolished, TFL iron exhibited two doublets overlapping those of [Fe4S4]2+ clusters in -S0 cells. This coincidence arose because of similar coordination environments of TFL iron and cluster iron. The TFL structure was more heterogeneous in the presence of IssA. Presented data suggest that IssA may coordinate insoluble iron sulfides as TFL iron, formed as a byproduct of anaerobic sulfur respiration under high iron conditions, which thereby reduces its toxicity to the cell. This was the first Mössbauer characterization of the ironome of an archaeon, and it illustrates differences relative to the iron content of better-studied bacteria such as Escherichia coli.

Biographical sketch: John Albert Key, 1890-1955.

This biographical sketch on John Albert Key corresponds to the historic text, The Classic: Epiphyseal coxa vara or displacement of the capital epiphysis of the femur in adolescence, available at DOI 10.1007/s11999-013-2913-y.

Biographical sketch: Georg Clemens Perthes, MD (1869-1927).

This biographical sketch on Georg Perthes corresponds to the historic text, The Classic: On Juvenile Arthritis Deformans (1910), available at DOI 10.1007/s11999-012-2433-1.

Biographical sketch: Themistocles Gluck (1853-1942).

This biographical sketch on Themistocles Gluck corresponds to the historic text, The Classic: Report on the positive results obtained by the modern surgical experiment regarding the suture and replacement of defects of superior tissue, as well as the utilization of re-absorbable and living tamponade in surgery (1891), available at DOI 10.1007/s11999-011-1837-7 .

Biographical sketch: George L. Walton, MD and Walter E. Paul, MD.

This biographical sketch on George L. Walton and Walter E. Paul corresponds to the historic text, The Classic: Contribution to the Study of Spinal Surgery: One Successful and One Unsuccessful Operation for Removal of Tumor (1905), available at DOI 10.1007/s11999-010-1664-2 .

Testing for the presence of positive-outcome bias in peer review: a randomized controlled trial.

BACKGROUND: If positive-outcome bias exists, it threatens the integrity of evidence-based medicine. METHODS: We sought to determine whether positive-outcome bias is present during peer review by testing whether peer reviewers would (1) recommend publication of a "positive" version of a fabricated manuscript over an otherwise identical "no-difference" version, (2) identify more purposefully placed errors in the no-difference version, and (3) rate the "Methods" section in the positive version more highly than the identical "Methods" section in the no-difference version. Two versions of a well-designed randomized controlled trial that differed only in the direction of the finding of the principal study end point were submitted for peer review to 2 journals in 2008-2009. Of 238 reviewers for The Journal of Bone and Joint Surgery and Clinical Orthopaedics and Related Research randomly allocated to review either a positive or a no-difference version of the manuscript, 210 returned reviews. RESULTS: Reviewers were more likely to recommend the positive version of the test manuscript for publication than the no-difference version (97.3% vs 80.0%, P < .001). Reviewers detected more errors in the no-difference version than in the positive version (0.85 vs 0.41, P < .001). Reviewers awarded higher methods scores to the positive manuscript than to the no-difference manuscript (8.24 vs 7.53, P = .005), although the "Methods" sections in the 2 versions were identical. CONCLUSIONS: Positive-outcome bias was present during peer review. A fabricated manuscript with a positive outcome was more likely to be recommended for publication than was an otherwise identical no-difference manuscript.

Biographical sketch: Sir John Charnley MD, 1911-1982.

This biographical sketch of Sir John Charnley corresponds to the historic text, The Classic: The Bonding of Prostheses to Bone by Cement, available at DOI 10.1007/s11999-010-1545-8 .

Biographical Sketch: Baron Joseph Lister, FRCS, 1827-1912.

This biographical sketch on Baron Joseph Lister corresponds to the historic text, The Classic: On the Antiseptic Principle in the Practice of Surgery (1867), available at DOI 10.1007/s11999-010-1320-x .