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A general approach to wavefront reception applicable to any type of wave allows to point out some overlooked aspects and ignored consequences of established theories. The Doppler and aberration effects of electromagnetic waves, the cosmological redshift and the measurement of durations are all perceptual phenomena, and as such require the use of reception rather than Lorentz-transformed coordinates, since perceived durations relate proper to proper durations whereas the famous time dilation of special relativity relates proper to improper durations. Taking this subtlety into account rehabilitates the controversial Poincaré ellipsoid whose polar equation is just the relativistic Doppler effect. The application of this approach to the Galilean case whose transformed and received wavefronts are homothetic, reveals new aberration relations and the existence of a transverse Doppler effect very similar, in proportion to the respective wave velocities, to the relativistic one, thus forbidding in practice the test of his theory proposed by Einstein. The reasons for the long persistence of a classical angular Doppler formula divorced from wavefront reception are discussed, one of them ironically being the theory of special relativity.

Oestrogen receptor‐alpha (ERα) positivity is intimately associated with the development of hormone‐dependent breast cancers. A major challenge in the treatment of these cancers is to understand and overcome the mechanisms of endocrine resistance. Recently, two distinct translation programmes using specific transfer RNA (tRNA) repertoires and codon usage frequencies were evidenced during cell proliferation and differentiation. Considering the phenotype switch of cancer cells to more proliferating and less‐differentiated states, we can speculate that the changes in the tRNA pool and codon usage that likely occur make the ERα coding sequence no longer adapted, impacting translational rate, co‐translational folding and the resulting functional properties of the protein. To verify this hypothesis, we generated an ERα synonymous coding sequence whose codon usage was optimized to the frequencies observed in genes expressed specifically in proliferating cells and then investigated the functional properties of the encoded receptor. We demonstrate that such a codon adaptation restores ERα activities to levels observed in differentiated cells, including: (a) an enhanced contribution exerted by transactivation function 1 (AF1) in ERα transcriptional activity; (b) enhanced interactions with nuclear receptor corepressor 1 and 2 [NCoR1 and NCoR2 (also known as SMRT) respectively], promoting repressive capability; and (c) reduced interactions with SRC proto‐oncogene, non‐receptor tyrosine kinase (Src) and phosphoinositide 3‐kinase (PI3K) p85 kinases, inhibiting MAPK and AKT signalling pathway.

Chaperone synthesis in response to proteotoxic stress is dependent on a family of transcription factors named heat shock factors (HSFs). The two main factors in this family, HSF1 and HSF2, are co-expressed in numerous tissues where they can interact and form heterotrimers in response to proteasome inhibition. HSF1 and HSF2 exhibit two alternative splicing isoforms, called α and β, which contribute to additional complexity in HSF transcriptional regulation, but remain poorly examined in the literature. In this work, we studied the transcriptional activity of HSF1 and HSF2 splicing isoforms transfected into immortalized Mouse Embryonic Fibroblasts (iMEFs) deleted for both Hsf1 and Hsf2, under normal conditions and after proteasome inhibition. We found that HSF1α is significantly more active than the β isoform after exposure to the proteasome inhibitor MG132. Furthermore, we clearly established that, while HSF2 had no transcriptional activity by itself, short β isoform of HSF2 exerts a negative role on HSF1β-dependent transactivation. To further assess the impact of HSF2β inhibition on HSF1 activity, we developed a mathematical modelling approach which revealed that the balance between each HSF isoform in the cell regulated the strength of the transcriptional response. Moreover, we found that cellular stress such as proteasome inhibition could regulate the splicing of Hsf2 mRNA. All together, our results suggest that relative amounts of each HSF1 and HSF2 isoforms quantitatively determine the cellular level of the proteotoxic stress response.

The authors conducted 2 experiments to study the metrics of spatial distance in a mental imagery task. In both experiments, participants first memorized the layout of a building containing 10 rooms with 24 objects. Participants then received mental imagery instructions and imagined how they walked through the building from one room to another. The authors manipulated Euclidean distance involved in these imaginary motions: Spatial distance measured in centimeters on the layout was either short or long. Independently, they varied categorical distance: The motions led through one room or two rooms. The time needed to imagine motions and response times to test probes indicated that both Euclidean distance and categorical distance affected mental imagery. The authors discuss the new finding of categorical distance effects in mental imagery and relate the results to earlier failures to find Euclidean distance effects in formally equivalent studies of narrative comprehension.