The propensity to bargain while on a vacation

This article assesses how tourists' bargaining motivations and attitudes moderate their willingness to return to Italy, where bargaining is perceived as one of the best ways to deal with sellers. A non-probability quota sampling technique was used to survey domestic tourists in Italy through an online questionnaire which encompassed 26 bargaining values and one item to measure the likelihood that the tourists would bargain at the same destination in the future. The data comprised a total of 812 observations. An order probit model and marginal effects were estimated to measure the tourists' propensity to return to Italy for bargaining purposes. The study findings indicate that tourists' propensity to return for bargaining purposes is taken with the awareness that they will not obtain what they expected; as a matter of fact, they are unlikely to care about the final result but instead engage in this behaviour to have fun.FCT - National Funding Agency for Science, Research and Technology [UID/ECO/04007/2013 CEFAGE

[Ca2+]i changes in guinea pig tracheal smooth muscle cells in culture: effects of Na+ and ouabain

The objective of this work was to confirm that the contractile effects of ouabain and Na+-free solutions in guinea pig tracheal rings are associated with increments in the cytosolic free Ca2+ concentration ([Ca2+]i) in cultured tracheal smooth muscle (TSM) cells. Cultured cells were a-actin positive. Histamine (50 mM) and Na+ -free solution elicited a transient increase in [Ca2+]I, while the responses to thapsigargin (1 µM) and ouabain (1 mM) were long lasting. However, carbachol (10, 200, and 500 mM) and high K+-solution produced no effect on [Ca2+]i, suggesting that cultured guinea pig TSM cells display a phenotype change but maintain some of the tracheal rings physiological properties. The transient rise in [Ca2+]i in response to the ce of extracellular Na+ and the effect of ouabain may indicate the participation of the Na+/Ca2+ exchanger (NCX) in the regulation of [Ca2+]i.El objetivo del presente trabajo es el de confirmar que los efectos contráctiles producidos por la ouabaína y la ausencia de Na+ en la solución en anillos de traquea de cobayo, se asocian a incrementos en la concentración libre de Ca2+ citosólico ([Ca2+]i) en células cultivadas de músculo liso traqueal de cobayo. Las células usadas en los experimentos eran positivas para a-actina de músculo liso. La histamina (50 µM) y las soluciones libres de Na+ producen un incremento transitorio en la [Ca2+]i mientras que la thapsigargina (1 µM) y la ouabaína (1 mM) dan lugar a incremento de larga duración. Sin embargo, el carbacol (10, 200 y 500 µM) y soluciones con alta concentración de K+ no producen cambios en la [Ca2+]i . Estos resultados sugieren que, en nuestras condiciones experimentales, las células cultivadas de músculo liso traqueal presentan cambios en su fenotipo, pero conservan algunas de las propiedades fisiológicas observadas en los anillos traqueales. El incremento transitorio de la [Ca2+]i producido por la ausencia de Na+ extracelular y el efecto de la ouabaína sugieren la participación del intercambiador Na+/Ca2+ (NCX) en la regulación de la [Ca2+]i

The folic acid metabolite 7,8-dihydrofolate can decrease the interactions of ACE2 with the Wild type, but not with the Beta and Delta SARS-CoV-2 variants: A silico study.

There is evidence that high levels of folic acid in human plasma may prevent SARS-CoV-2 infections or reduce its symptoms. However, the mechanisms that enable this inhibition are still unknown. This article proves, through molecular dynamics simulation, that folic acid metabolite 7,8-dihydrofolate (DHF) has high affinity to bind as ligands to the angiotensin-converting enzyme 2 (ACE2), and when this complex has been formed, the Wild type SARS-CoV-2 virus cannot bind to the ACE2 receptor, possibly inhibiting infection to the host cell. In contrast, the Beta and Delta variants of this same virus can join the ACE2 with high affinity even with the presence of DHF. This results lead to the conclusion that DHF may inhibit infection from the Wild type SARS-CoV-2 virus, but not its Beta and Delta variants. These results could explain the almost double increase in severe cases of COVID-19 due to the delta variant in pregnant women compared to the Wild type SARS-CoV-2