Detection of anti-correlation of hot and cold baryons in galaxy clusters.

The largest clusters of galaxies in the Universe contain vast amounts of dark matter, plus baryonic matter in two principal phases, a majority hot gas component and a minority cold stellar phase comprising stars, compact objects, and low-temperature gas. Hydrodynamic simulations indicate that the highest-mass systems retain the cosmic fraction of baryons, a natural consequence of which is anti-correlation between the masses of hot gas and stars within dark matter halos of fixed total mass. We report observational detection of this anti-correlation based on 4 elements of a 9 × 9-element covariance matrix for nine cluster properties, measured from multi-wavelength observations of 41 clusters from the Local Cluster Substructure Survey. These clusters were selected using explicit and quantitative selection rules that were then encoded in our hierarchical Bayesian model. Our detection of anti-correlation is consistent with predictions from contemporary hydrodynamic cosmological simulations that were not tuned to reproduce this signal.

The impact a surgeon has on primary amputee prosthetic rehabilitation: A survey of residual lower limb quality.

BACKGROUND: Substantial improvements have been perceived in surgical results following major lower limb amputation, but there remains observed variation in amputation quality for patients referred for prosthetic rehabilitation from different hospitals. OBJECTIVES: To assess various elements that influence residual limb quality and evaluate their impact on progress through initial prosthetic rehabilitation and mobility outcome after rehabilitation. STUDY DESIGN: Clinical survey. METHODS: A revised 10-item residual limb scoring system was used to survey a succession of 95 primary amputees with transtibial and transfemoral amputations (100 residual limbs) presenting for rehabilitation. RESULTS: The majority of residual limbs scored highly, supporting the perception of generally good amputation quality. There were significant differences in average residual limb scores between some hospitals. The overall scores showed weak or minimal correlation to progress through rehabilitation and mobility outcome but residual limbs scoring higher in seven of the items of the score showed significant advantages in key aspects of progress or mobility at discharge. CONCLUSION: There is need for continued collaboration between surgeons and rehabilitation centres to ensure consistent high standards. The revised residual limb score used in this survey needs further refinement for future use. Clinical relevance Residual limb quality is an important component influencing prosthetic rehabilitation. This survey of residual limbs at one Rehabilitation Centre suggests encouragingly good surgical results but highlights differences between hospitals. A particular issue is the need for effective collaboration between surgeons and prosthetic rehabilitation professionals to optimise residual limb preparation.

Comparison of human Nrf2 antibodies: A tale of two proteins.

The Nrf2 transcription factor is a master regulator of the cellular defense against oxidative and electrophilic stress. An increase in Nrf2 protein levels and an accumulation of Nrf2 in the nucleus are key parts of the Nrf2 activation mechanism. The western blot technique remains the most widely used method to assess these changes. A well-characterized, specific antibody that is commercially available would greatly enhance these studies in the field. Here, an apparently highly specific Nrf2 monoclonal antibody, EP1808Y from Abcam, is compared with the most widely used Nrf2 antibodies, H-300 and C-20, both from Santa Cruz Biotechnology, in a panel of human cell lines. In addition to detecting Nrf2, EP1808Y avidly detects another protein present in two of the three cell lines tested. This protein can be mistaken for Nrf2 as it co-migrates with verified Nrf2 on two different polyacrylamide gel types. However, unlike Nrf2, its levels and cytoplasmic localization are unaffected by treatment with Nrf2 activators. The possibility that this band corresponds to a form of Nrf2 was excluded by siRNA and immunodepletion experiments. Finally, the monoclonal antibody D1Z9C from Cell Signaling was found to detect Nrf2 with the highest specificity of these four antibodies.