Effects of concavity on the motion of a body immersed in a Vlasov gas

We consider a body immersed in a perfect gas, moving under the action of a constant force $E$ along the $x$ axis . We assume the gas to be described by the mean-field approximation and interacting elastically with the body. Such a dynamic was studied in previous papers In these studies the asymptotic trend showed no sensitivity whatsoever to the shape of the object moving through the gas. In this work we investigate how a simple concavity in the shape of the body can affect its asymptotic behavior; we thus consider the case of hollow cylinder in three dimensions or a box-like body in two dimensions. We study the approach of the body velocity $V (t)$ to the limiting velocity $V_{\infty}$ and prove that, under suitable smallness assumptions, the approach to equilibrium is $| V_{\infty}-V(t)| \approx C t^{-3}$ both in two or three dimensions, being $C$ a positive constant. This approach is not exponential, as typical in friction problems, and even slower than for the simple disk and the convex body in $\mathbb{R}^2$ or $\mathbb{R}^3$

Inherent Dangers in Orogenital Sex During Pregnancy

Coitus and cunnilingus during pregnancy are generally safe; whereas orogenital sex involving vaginal air insufflations can be very dangerous, causing even the death of the women. We carried out a search of case reports and reviews concerning air embolism during pregnancy due to orogenital sex. Physicians consultations must cover all the rules of safe sexual behavior, including avoidance of vaginal air insufflations in the third trimester.Keywords: Air embolism, cunnilingus, orogenital sex, pregnanc

Study of PVI-based diagnostics for 1D time-series in space plasma

Context. In the last few decades, increasing evidence has been found in both numerical studies and high-resolution in situ data that magnetic turbulence spontaneously generates coherent structures over a broad range of scales. Those structures play a key role in energy conversion because they are sites where magnetic energy is locally dissipated in plasma heating and particle energization. How much turbulent energy is dissipated via processes such as magnetic reconnection of thin coherent structures, namely current sheets, remains an open question. Aims. We aim to develop semi-automated methods for detecting reconnection sites over multiple spatial scales. This is indeed pivotal in advancing our knowledge of plasma dissipation mechanisms and for future applications to space data. Methods. By means of hybrid-Vlasov-Maxwell 2D-3V simulations, we combine three methods based on the partial variance of increments measured at a broad range of spatial scales and on the current density, which together, and in a synergistic way, provide indications as to the presence of sites of magnetic reconnection. We adopt the virtual satellite method, which in upcoming works will allow us to easily extend this analysis to in situ time-series. Results. We show how combining standard threshold analysis to a 2D scalogram based on magnetic field increments represents an efficient diagnostic for recognizing reconnecting structure in 1D spatial- and time-series. This analysis can serve as input to automated machine-learning algorithms

A diguanylate cyclase regulates motility and biofilm formation in Bordetella bronchiseptica mediated by a GGDEF-EAL protein

Bordetella bronchiseptica is a bacterium that causes respiratory infections in a variety of mammalian hosts. We have already described c-di-GMP role in motility and biofilm formation. We previously showed that over expressing BdcA (Bordetella diguanylate cyclase A) triggers high c-di-GMP levels and significantly impaired movement and enhanced biofilm formation.Facultad de Ciencias Exacta

A diguanylate cyclase regulates motility and biofilm formation in Bordetella bronchiseptica mediated by a GGDEF-EAL protein

Bordetella bronchiseptica is a bacterium that causes respiratory infections in a variety of mammalian hosts. We have already described c-di-GMP role in motility and biofilm formation. We previously showed that over expressing BdcA (Bordetella diguanylate cyclase A) triggers high c-di-GMP levels and significantly impaired movement and enhanced biofilm formation.Facultad de Ciencias Exacta