104 research outputs found
“Superstition ain’t the way”. The optimism of the conspiracy theorist
No full textThis article addresses the topic of conspiracy theories from a rhetorical and philosophical perspective through a recent case study: the Netflix docuseries The Ancient Apocalypse by Graham Hancock1. In this TV series, the host – the author – hypothesizes a conspiracy by academic archaeology, which does not accept the idea of the existence of a highly technically developed ancient civilization that disappeared before the last ice age. The reason for this resistance on the part of archaeologists would be their desire to maintain a position of power and prestige that they would have to give up if they accepted a paradigm shift. We will use Hancock’s speeches as a textual corpus to be analyzed from a rhetorical point of view, and we will follow the philosophical hypothesis that conspiracy theories should be understood through the phenomenon of superstition (which is different from magic, § 1). We devote a paragraph to each technical proof used to achieve persuasion. First, éthos (§ 2), which focuses on the construction of the speaker as an outsider, credible because he is inconvenient. We then analyze the logos (§ 3), characterized by fallacies, ambivalent logic, and the mythological narrative as historical evidence. Finally (§ 4), we focus on pathos, which exhibits a form of detachment and a disposition to inaction
[Ca2+]i recordings and the inactivation of the high-voltage activated Ca2+ currents in the adult rat sensory neuron.
No full textFast, single cell, measurement of the average cytosolic [Ca2+]i with the Fura-2 technique suggests that the depolarization induced [Ca2+]i rise is entirely due to entry through the voltage-activated Ca2+ channels. Involvement of a Ca(2+)-induced Ca(2+)-release process is not evident. Under physiological cytosolic buffering the current-induced [Ca2+]i rise persists for seconds and decays exponentially (tau = 7 s). Analysis of the [Ca2+]i changes during two-pulse protocols indicates that the purely voltage-dependent inactivation of the high voltage-activated (HVA) channels, in the range -80/+70 mV, is a slow process (0.2-1 s) which removes at most 40% of the current. On the contrary, Ca(2+)-dependent inactivation acts in a fast way and it is therefore responsible for the fast inactivating phase of the current; this phase disappears under sustained [Ca2+]i loads, and reappears when redistribution of free Ca2+ takes place. A suitable correction may be devised to compensate for the Ca(2+)-dependent inactivation
Alteration of T-state binding properties of naturally glycated hemoglobin, HbA1c.
No full textThe thermodynamic and kinetic properties of the most abundant glycated hemoglobin in human blood, HbA(1c), have been studied in detail. They display significant differences as compared to normal hemoglobin, HbA0, in that (1) the shape of the oxygen binding curve of HbA(1c) in the Hill plot is markedly asymmetrical, with a lower asymptote extending up to approximately 40% oxygen saturation, and the oxygen affinity of the T state being tenfold higher than in HbA0; (2) oxygen pulse experiments on HbA(1c) show a slower rate of ligand dissociation (k = 25 s-1) even at low levels of oxygen saturation, where the T state is largely predominant; (3) kinetics of CO combination to deoxy HbA(1c) followed by means of stopped-flow experiments reveal the presence of a quickly reacting component, whose fraction increases upon dilution of hemoglobin. These results show that in contrast to what has been stated by other authors, HbA(1c) displays functional properties markedly different from HbA0. Analysis indicates that glycation of human hemoglobin affects the T quaternary structure, bringing about a more 'relaxed' T state and leading to preferential binding to one type of chain (which is unaffected by chloride ions)
The effect of pH and D-glycerate 2,3-bisphosphate on the O2 equilibrium of normal and SH(beta 93)-modified human hemoglobin
No full textThe present paper reports data for the effect of pH and D-glycerate 2,3-bisphosphate (D-glycerate-2,3-P2) on the oxygen equilibrium of normal and SH(beta 93)-modified human hemoglobin. At sufficiently high D-glycerate-2,3-P2 concentrations, both oxy and deoxy forms of HbA are saturated with the organic phosphate at all pH values between 6 and 9. Furthermore the difference in the affinity for D-glycerate-2,3-P2 between deoxy and oxy hemoglobin remains constant with pH, implying that the pK values of the Bohr effect groups in deoxy and oxyhemoglobin are not affected by the presence of D-glycerate-2,3-P2 on the hemoglobin molecule. In the hemoglobins modified in position beta 93, the difference in affinity between deoxy and oxy hemoglobin for D-glycerate-2,3-P2 decreases with decrease in pH due mainly to a decrease in the affinity of the deoxy form for D-glycerate-2,3-P2. The effect of the chemical modification appears to be primarily a change in pK of a Bohr group in deoxy hemoglobin which is especially pronounced in the presence of phosphates
Localization of active lesions of the colon by radioisotope labelled Sucralfate and Autologos Leucocytes
No full textP2y purinoceptors in normal NIH 3T3 and in NIH 3T3 overexpressing c-ras
No full textThe ability of purinergic agonists to induce Ca2+ responses has been tested in two lines of murine fibroblasts: normal NIH 3T3 fibroblasts and NIH 115.14, a clone expressing high levels [1] of the c-ras protooncogene. Both kinds of cells are responsive to ATP in the range 1 microM-1 mM; ADP and ATP gamma S are almost as potent as ATP, while AMP is unable to elicit a response. Ca2+ measurements performed in single cells by image analysis show great variability among cells but in each individual responding cell the Ca2+ rise occurs in an all-or-none fashion. The transient Ca2+ response does not depend on influx from the extracellular medium. Electrophysiological experiments reveal the activation of an outward current (at -50 mV) by ATP, probably due to Ca(2+)-activated K+ channels, confirming the absence of a substantial Ca2+ influx. Finally, stimulation by ATP produces a small but significant increase in the production of inositol phosphates. These results indicate that these cell lines possess purinergic receptors which are not integral membrane channels and which are coupled to InsP3 formation and may be therefore classified as P2Y
L'angiodisplasia del colon.Osservazioni su due pazienti anziani trattati chirurgicamente
No full text
- …
