Four direct measurements of the fine-structure constant 13 billion years ago.

Observations of the redshift z = 7.085 quasar J1120+0641 are used to search for variations of the fine structure constant, α, over the redshift range 5.5 to 7.1. Observations at z = 7.1 probe the physics of the universe at only 0.8 billion years old. These are the most distant direct measurements of α to date and the first measurements using a near-IR spectrograph. A new AI analysis method is employed. Four measurements from the x-shooter spectrograph on the Very Large Telescope (VLT) constrain changes in a relative to the terrestrial value (α0). The weighted mean electromagnetic force in this location in the universe deviates from the terrestrial value by Δα/α = (α z - α0)/α0 = (-2.18 ± 7.27) × 10-5, consistent with no temporal change. Combining these measurements with existing data, we find a spatial variation is preferred over a no-variation model at the 3.9σ level.

Study of superficial basal cell carcinomas and Bowen disease by qualitative and quantitative ultrasound biomicroscopy approach.

In the present work the ultrasound biomicroscopy (UBM) technique is applied in the study of cutaneous cell carcinomas in vitro, including superficial basal cell carcinomas (BCC) and Bowen disease (BD) cases. The evaluation was made by qualitative observation of UBM images, and by quantitative computation of integrated backscatter coefficient (IBC), obtained with a system working at a central frequency of 45 MHz. The characteristic histological structures for each studied tumor type were well identified in the images. The IBC values observed in the two carcinoma types inside the affected region, were different between them, next to 10(-4) [Sr(-1).mm(-1)] for superficial BCC tissues, and to 10(-5) [Sr(-1).mm(-1)1] for BD tissues; moreover, in the deeper dermis (slight affected region) the backscatter was next to 10(-3) [Sr(-1).mm(-1)] for both tissue groups, and agrees with the values obtained for healthy skin both, in this study and in previous works. The results here obtained encourage the continuation of the work, with a higher number of samples, attempting to obtain more significant results.

Cosmology with varying constants.

The idea of possible time or space variations of the 'fundamental' constants of nature, although not new, is only now beginning to be actively considered by large numbers of researchers in the particle physics, cosmology and astrophysics communities. This revival is mostly due to the claims of possible detection of such variations, in various different contexts and by several groups. I present the current theoretical motivations and expectations for such variations, review the current observational status and discuss the impact of a possible confirmation of these results in our views of cosmology and physics as a whole.