Study of functional adaptation of the visual system in the conditions of experimental modes of artificial gravity, created on a short-radius centrifuge

Purpose. To evaluate the functional adaptation of the visual system in the conditions of experimental modes of artificial gravity created on a short-radius centrifuge.Materials and methods. The study involved 9 healthy volunteers (9 eyes) aged 31.2±6 years. Each test person has passed 3 rotations on the short-radius centrifuge. The current factor in the tests was the overloads in the direction of ≪head-pelvis≫. Rotations were carried out in three modes, further conditionally designated ≪Mode 1≫, ≪Mode 2≫, ≪Mode 3≫ (maximum value of overloads at feet level up to 2.0; 2.4 and 2.9 G, respectively). Before and after each rotation the subjects underwent refractometry, determined pupil diameter, intraocular pressure and hydrodynamic parameters of the eye, evaluated hemodynamics in the vessels of the eye, orbit and i nternal carotid artery.Results. Intraocular pressure after the rotation in the modes 1 and 2 did not change, in the mode 3 – decreased by 1.0 mmHg according to tonometry (p=0.024), according to tonography by 2.8 mmHg (p=0.007) which correlated with a decrease in the rate of intraocular fluid production by 0.67 mm3 (p=0.046). After rotation in the mode 1 the blood flow rate in the internal carotid artery and the ophthalmic artery did not change, in the mode 2 the final diastolic blood flow rate in the internal carotid artery decreased by 2.6 cm/s (p=0.011), in the ophthalmic artery did not change, in the mode 3 the blood flow rate in the internal carotid artery did not change, in the ophthalmic artery – increased by 9.5 cm/s (p=0.015).Conclusions. Changes hemo- and ophthalmo-hydrodynamics in healthy subjects are within normal limits, which suggest that the visual system has wide possibilities of functional adaptation to the conditions of experimental modes of artificial gravity

mRNA Translation: Fungal Variations on a Eukaryotic Theme

The accurate transfer of information from a nucleotide-based code to a protein-based one is at the heart of all life processes. The actual information transfer occurs during protein synthesis or translation, and is catalysed by ribosomes, supported by a large host of additional protein activities—the translation factors. This chapter reviews how the different eukaryotic initiation, elongation and termination factors assist the ribosome in establishing appropriate contacts with mRNAs during translation initiation, decode the genetic code during translation elongation, and finally release the newly made polypeptide and reuse the ribosomes during the termination and recycling phases