The translocation of tRNAs through the ribosome proceeds through numerous small steps in which tRNAs gradually shift their positions on the small and large ribosomal subunits. The most urgent questions are: (i) whether these intermediates are important; (ii) how the ribosomal translocase, the GTPase elongation factor G (EF‐G), promotes directed movement; and (iii) how the energy of GTP hydrolysis is coupled to movement. In the light of recent advances in biophysical and structural studies, we argue that intermediate states of (...) translocation are snapshots of dynamic fluctuations that guide the movement. In contrast to current models of stepwise translocation, kinetic evidence shows that the tRNAs move synchronously on the two ribosomal subunits in a rapid reaction orchestrated by EF‐G and GTP hydrolysis. EF‐G combines the energy regimes of a GTPase and a motor protein and facilitates tRNA movement by a combination of directed Brownian ratchet and power stroke mechanisms. (shrink)

James A. Diefenbeck, Wayward Reflections on the History ofPhilosophyThomas R. Flynn Sartre, Foucault and Historical Reason. Volume 1:Toward an Existential Theory of HistoryMark Golden and Peter Toohey Inventing Ancient Culture:Historicism, Periodization and the Ancient WorldZenonas Norkus Istorika: Istorinis IvadasEverett Zimmerman The Boundaries of Fiction: History and theEighteenth‐Century British Novel.

Maurice Merleau-Ponty’s ‘flesh of the world’ speaks to an embodied connection to the spaces we inhabit deeply, primally, elementally. Flesh suggests water and its circulations, air and its respirations, earth and its conformations, fire and its inspirations. Flesh speaks to our bodily relations with the elements of a more-than-human world. This paper explores the felt imperative to these relations where, as Merleau-Ponty put it, ‘all distance is traversed’ and wherein movement arises not specifically in the body, but in the nexus (...) and intertwining of bodily engagement with the world. There is a primacy to movement that registers in the living body in its carnal ties to the elements of the world’s flesh. The ‘radical reflection’ on the ‘flesh of the world’ to which this analysis aspires in turn bears upon the general field of gestural reciprocities and connections, providing the insight that intimate gestures of the flesh, such as the embrace, are primordial attunements, motions of rhythm and reciprocity, that emanate from the world in identification with it. The embrace is fundamentally, elementally, a gesture of landscape dwelling. A phenomenology of elemental motions provides the textual reminder that to be at home in various landscapes means to know what it is to be embraced corporeally, sensually, within the human and especially the more-than-human folds of the world. Indo-Pacific Journal of Phenomenology , Volume 6, Edition 1 May 2006. (shrink)

Un sujet peu exploré dans la phénoménologie husserlienne est encore à ce jour le champ des émotions, longtemps minoré. Or la publication du volume des Husserliana 'Sentiment et valeur' montre que-les émotions sont un thème qui préoccupa Husserl durant toute sa vie. La raison de cette invisibilité est moins son manque d'importance aux yeux du phénoménologue que la difficulté de lui trouver une place cohérente. Si les actes cognitifs (perceptifs, judicatifs, mémoriels, imaginatifs) représentent souvent le cas d'étude privilégié eu égard (...) à la visée de connaissance qui y apparaît en majeur, les affects (émotions, volitions, valeurs) obéissent à une autre logique ou, du moins, à une logique plus complexe : non seulement descriptive, mais aussi génétique-dynamique. Ce qui se joue avec les émotions est moins la connaissance d'un objet que les tensions, les satisfactions et les déceptions propres aux processus vécus des forces psychiques et de leurs valeurs pour le sujet. Un tel défi est ici relevé. On identifie les lieux où les émotions entrent en scène en esthétique, dans la pragmatique de l'action et en philosophie de l'esprit, en lien avec sciences cognitives et phénoménologie. Dès lors se profile une ligne directrice nouvelle autour de la complexité de la dynamique émotionnelle et de l'obsolescence conséquente du clivage cognition-émotion"--Page 4 of cover. (shrink)

Shepard's article presents an impressive application of the mathematics of symmetry to the understanding of motion. However, there are basic psychological phenomena that the model does not handle well. These include the importance of the orientations of rotational motions to salient reference systems for the understanding of the motions. An alternative model of the understanding of rotations is sketched. [Shepard].

What I call the minimal notion of truth is just that which the redundancy thesis claims suffices for all legitimate purposes. I argue that the minimal notion is legitimate and useful whatever one's preferred theory of truth. I rebut some arguments against the redundancy thesis which are in effect arguments against the legitimacy of the minimal notion. Finally I compare the minimal notion with a slightly stronger notion I call the semiminimal notion, and argue that this does issue a refutation (...) of the redundancy thesis as I have defined it. (shrink)

Ribosome biogenesis includes the making and processing of ribosomal RNAs, the biosynthesis of ribosomal proteins from their mRNAs in the cytosol and their transport to the nucleolus to assemble pre‐ribosomal particles. Several stresses including cellular senescence reduce nucleolar rRNA synthesis and maturation increasing the availability of ribosome‐free ribosomal proteins. Several ribosomal proteins can activate the p53 tumor suppressor pathway but cells without p53 can still arrest their proliferation in response to an imbalance between ribosomal proteins and mature rRNA (...) production. Recent results on senescence‐associated ribogenesis defects (SARD) show that the ribosomal protein S14 (RPS14 or uS11) can act as a CDK4/6 inhibitor linking ribosome biogenesis defects to the main engine of cell cycle progression. This work offers new insights into the regulation of the cell cycle and suggests novel avenues to design anticancer drugs. (shrink)

Construction of the eukaryotic ribosome is a complex process in which a nascent ribosomal RNA (rRNA) emerging from RNA Polymerase I hierarchically folds into a native three‐dimensional structure. Modular assembly of individual RNA domains through interactions with ribosomal proteins and a myriad of assembly factors permit efficient disentanglement of the error‐prone RNA folding process. Following these dynamic events, long‐range tertiary interactions are orchestrated to compact rRNA. A combination of genetic, biochemical, and structural studies is now providing clues into how (...) a nascent rRNA is transformed into a functional ribosome with high precision. With this essay, we aim to draw attention to the poorly understood process of establishing correct RNA tertiary contacts during ribosome formation. (shrink)

The conserved ribosomal protein uS3 in eukaryotes has long been known as one of the essential components of the small (40S) ribosomal subunit, which is involved in the structure of the 40S mRNA entry pore, ensuring the functioning of the 40S subunit during translation initiation. Besides, uS3, being outside the ribosome, is engaged in various cellular processes related to DNA repair, NF‐kB signaling pathway and regulation of apoptosis. This review is devoted to recent data opening new horizons in understanding (...) the roles of uS3 in such processes as the assembly and maturation of 40S subunits, ensuring proper structure of 48S pre‐initiation complexes, regulation of initiation and ribosome‐based RNA quality control pathways. Besides, we summarize novel results on the participation of the protein in processes beyond translation and consider biomedical implications of previously known and recently found extra‐ribosomal functions of uS3, primarily, in oncogenesis. (shrink)

In a recent paper in Astrophysics and Space Science Vol. 364 no. 11 (2019), S. Ershkov & D. Leschenko presented a new solving procedure for Euler-Poisson equations for solving momentum equations of the CR3BP near libration points for uniformly rotating planets having inclined orbits in the solar system with respect to the orbit of the Earth. The system of equations of the CR3BP has been explored with regard to the existence of an analytic way of presentation of the approximated solution (...) in the vicinity of libration points. A new and elegant ansatz has been suggested in their publication whereby, in solving, the momentum equation is reduced to a system two coupled Riccati ODEs. In this paper, we presented a numerical solution of such coupled Riccati ODEs using Mathematica software package. (shrink)

Dormancy or hibernation is a non‐proliferative state of cells with low metabolic activity and gene expression. Dormant cells sequester ribosomes in a translationally inactive state, called dormant/hibernating ribosomes. These dormant ribosomes are important for the preservation of ribosomes and translation shut‐off. While recent studies attempted to elucidate their modes of formation, the regulation and roles of the diverse dormant ribosomal populations are still largely understudied. The mechanistic details of the formation of dormant ribosomes in stress and especially their disassembly during (...) recovery remain elusive. In this review, we discuss the roles of dormant ribosomes and their potential regulatory mechanisms. Furthermore, we highlight the paradigms that need to be answered in the field of ribosomal dormancy. (shrink)

When observers view a rapidly moving stimulus they may see only a static streak. We report that there can be a transient percept of motion if such a moving stimulus is preceded or followed by a stationary image of that stimulus. A ring of dots was rotated so rapidly observers only saw a continuous outline circle and could not report its rotation direction. When an objectively stationary ring of dots preceded or followed this rotating ring, the stationary ring appeared to (...) visibly launch into motion from a standstill or visibly rotate to a halt, principally in the same direction as the actual rapid rotation. Thus, motions too rapid to be consciously perceived as motion can nonetheless be processed by the visual system, and generate neural transition states that are consciously experienced as motion percepts. We suggest such transition states might serve a unifying function by bridging discontinuous motion states. (shrink)

Quarum causas in orbibus sub suppremo collocatis indagantes, in suppremo enim uniformitas semper cernitur, exploratum habuerunt id prouenire ex motibus giratiuis lulabinis appellatis, factis quidem a permistione motus orbis super suis polis cum motu eiusdem super polis alterius, itaque ex multis motibus simul collectis unus fit motus. Quae quidem theorica phisicis conformis rationibus cunctis ueteribus ad Aristotelem philosophorum principem usque uigebat, quin immo sui summi acie ingenii eam 2 de coelo textu commentario 35 teste Auerroe innuere non desinit. Qalo Qalonymos.

What is an occurrent mental state? According to a common scholastic answer such a state is at least in part a quality of the mind. When I newly think about a machiatto, say, my mind acquires a new quality. However, according to a view discussed by John Buridan (who rejects it) and John of Mirecourt (who is condemned in 1347 for considering it “plausible”), an occurrent mental state is not even in part a quality. After sketching some of the history (...) of this position, I will present two common arguments against it—the argument from change and the argument from agency. I will then turn to Mirecourt’s own position on the matter. Mirecourt, I show, in fact offers us two different theories about occurrent mental states. The first, which I call the conservation theory, accepts that mental states are in part qualities. However, a mental state is a quality together with an action on the side of the mind, namely, its conservation of a quality within itself. The second position, which I will call the pure-action theory, holds that an occurrent mental state is not even in part a quality; instead, it is an action the mind performs which is neither the production nor the conservation of a quality within itself. Mirecourt characterizes such pure actions as “modes” of the mind, and it is this position which is condemned in 1347. In the final section, I turn to an objection that both Buridan and Mirecourt raise against the pure-action theory: if accidental states of the mind are mere modes of the mind, then why not suppose that all accidents are mere modes of the subjects which they qualify? (shrink)

A partir d'un examen critique des théories des passions de Descartes à Spinoza, O. Svec élabore une théorie phénoménologique des émotions destinée à dépasser l'alternative entre les théories somatiques et les théories cognitives. Il apporte un regard synthétique sur les théories contemporaines des émotions.

Cet ouvrage met en cause la dichotomie régnante « raison contre émotion », élément fondamental d'un prèt-à-penser qui règne sur les études d'argumentation et qu'on retrouve parfois dans les études du discours. Cette opposition fait obstacle à l'observation et à l'analyse du jeu des émotions parlées et écrites, et engage les études sur l'argumentation ordinaire dans l'impasse d'un langage « an-émotif », quasi pathologique. Mettant en jeu des valeurs qui expriment les intérèts et fondent l'identité des locuteurs, les situations argumentatives (...) sont profondément émotionnantes. Ce livre propose une approche holiste, et non psychologique, de l'émotion, vue non pas comme une Réponse passive à une situation Stimulus, mais comme une activité signifiante, formatant le discours et la situation de parole. Sous la notion de construction argumentative des émotions, il défend la thèse de l'inséparabilité des raisons et des émotions dans les discours argumentatifs ordinaires. (shrink)

The levels of different classes of mitochondrially encoded transcripts are developmentally regulated in sea urchin embryos, as a result of selection between mutually exclusive synthetic pathways. I propose a simple model to explain these observations, based on a dual role for mitochondrial ribosomes and translation factors in RNA synthesis as well as in translation. This effect may be exerted either at the transcriptional or post‐transcriptional level (or both), and is potentially generalizable to mammalian mtDNA and to other systems.