Organic Carbon Burial following the Middle Eocene Climatic Optimum (MECO) in the central - western Tethys

We present trace metal geochemistry and stable isotope records for the middle Eocene Alano di Piave section, NE Italy, deposited during magnetochron C18n in the marginal Tethys Ocean. We identify a $\sim$ 500 kyr long carbon isotope perturbation event we infer to be the middle Eocene Climatic Optimum (MECO) confirming the northern hemisphere expression and global occurrence of MECO. Interpreted peak climatic conditions are followed by the rapid deposition of two organic rich intervals ($\le$3\% TOC) and contemporaneous positive $\delta^{13}$C excursions. These two intervals are associated with increases in the concentration of sulphur and redox-sensitive trace metals, and low concentrations of Mn, as well as coupled with the occurrence of pyrite. Together these changes imply low, possibly dysoxic, bottom water O$_{2}$ conditions promoting increased organic carbon burial. We hypothesize that this rapid burial of organic carbon lowered global {\it p}CO$_{2}$ following the peak warming and returned the climate system to the general Eocene cooling trend

Neural control on multiple time scales: Insights from human stick balancing

The time-delayed feedback control mechanisms of the nervous system are continuously subjected to the effects of uncontrolled random perturbations (herein referred to as noise). In this setting the statistical properties of the fluctuations in the controlled variable(s) can provide non-invasive insights into the nature of the underlying control mechanisms. We illustrate this concept through a study of stick balancing at the fingertip using high speed motion capture techniques. Experimental observations together with numerical studies of a stochastic delay differential equation demonstrate that on time scales short compared to the neural time delay (“fast control”), parametric noise provides a non-predictive mechanism that transiently stabilizes the upright position of the balanced stick. Moreover, numerical simulations of a delayed random walker with a repulsive origin indicate that even an unstable fixed point can be transiently stabilized by the interplay between noise and time delay. In contrast, on time scales comparable to the neural time delay (“slow control”), feedback and feedforward control mechanisms become more important. The relative contribution of the fast and slow control mechanisms to stick balancing is dynamic and, for example, depends on the context in which stick balancing is performed and the expertise of the balancer

First record of Acanthurus chirurgus (Perciformes: Acanthuridae) in the Mediterranean Sea, with some distributional notes on Mediterranean Acanthuridae

The occurrence of the doctorfish Acanthurus chirurgus is reported for the first time in the Mediterranean Sea, off Elba Island, Tyrrhenian Sea (42.726667° N, 10.434444° E). This record is tentatively related to aquarium release. The occurrence of Acanthuridae in the Mediterranean Sea is briefly reviewed, and some distributional notes on Acanthurus coeruleus and Acanthurus monroviae in the Mediterranean are provided

Can be gravitational waves markers for an extra-dimension?

The main issue of the present letter is to fix specific features (which turn out being independent of extradimension size) of gravitational waves generated before a dimensional compactification process. Valuable is the possibility to detect our prediction from gravitational wave experiment without high energy laboratory investigation. In particular we show how gravitational waves can bring information on the number of Universe dimensions. Within the framework of Kaluza-Klein hypotheses, a different morphology arises between waves generated before than the compactification process settled down and ordinary 4-dimensional waves. In the former case the scalar and tensor degrees of freedom can not be resolved. As a consequence if were detected gravitational waves having the feature here predicted (anomalous polarization amplitudes), then they would be reliable markers for the existence of an extra dimension.Comment: 5 pages, two figure, to appear on Int. Journ. Mod. Phys.

Posterior reconstruction during robotic-assisted radical cystectomy with intracorporeal orthotopic ileal neobladder: description and outcomes of a simple step

A posterior reconstruction (PR) might improve the fluidity and delicacy of the maneuvers related to the neovesico-urethral anastomosis during robotic-assisted radical cystectomy (RARC). Our objective is to describe in detail the surgical steps of PR and to assess its feasibility and functional outcomes. The data regarding patients undergoing a totally intracorporeal RARC with neobladder and PR for high-grade and/or muscle-invasive urothelial cancer of the bladder at Karolinska University Hospital between October 2015 and November 2016 by a single surgeon (PW) were reviewed. Prior to the anastomosis, a modified posterior Rocco’s repair involving the Denonvillier’s fascia, the rhabdosphincter, and the posterior side of the ileal neobladder neck was performed. The steps are shown in a video at https://doi.org/10.1089/vid.2019.0029. The primary outcome was urinary continence; the secondary outcomes were urinary leakage, intermittent catheterization, and complications related to the reconstructive steps. Eleven male patients with a median age and BMI of 67 years and 24, respectively, underwent RARC with PR associated to the neovesico-urethral anastomosis. Overall and posterior reconstruction time were 300′ (195–320) and 6′ (4–7), respectively. The daytime and nighttime continence rates were 100% and 44% at 12 months, respectively; the median pad weight was 3.5 g and 108 g at daytime and nighttime, respectively. One urinary leakage from the urethrovesical anastomosis was treated conservatively. Two patients perform intermittent catheterization. The posterior reconstruction during RARC is safe and feasible, providing good continence rates. It supported a careful suturing of the anastomosis as well as an uncomplicated catheter placement

Exact expression for the diffusion propagator in a family of time-dependent anharmonic potentials

We have obtained the exact expression of the diffusion propagator in the time-dependent anharmonic potential $V(x,t)={1/2}a(t)x^2+b\ln x$. The underlying Euclidean metric of the problem allows us to obtain analytical solutions for a whole family of the elastic parameter a(t), exploiting the relation between the path integral representation of the short time propagator and the modified Bessel functions. We have also analyzed the conditions for the appearance of a non-zero flow of particles through the infinite barrier located at the origin (b<0).Comment: RevTex, 19 pgs. Accepted in Physical Review

MHD in von Kármán swirling flows, development and first run of the sodium experiment

URL: http://www-spht.cea.fr/articles/s01/004 MHD dans les écoulements de von Kármán | Collaboration VKSNATO Science Series II 26, 35-50 (2001). NATO Advanced Research Workshop, Dynamo and Dynamics, A Mathematical ChallengeWe describe the motivations, development and first run of the Von Kármán Sodium (VKS) experiment built to study high Reynolds number magnetohydrodynamics and applications to the dynamo effect. The flow is optimized using water experiments at scale 1/2 and kinematic dynamo simulations. In VKS run1, induction measurements are made in the presence of an externally applied field. Results are reported concerning the geometry of the induced field and its fluctuations in time

Gauge theories as a geometrical issue of a Kaluza-Klein framework

We present a geometrical unification theory in a Kaluza-Klein approach that achieve the geometrization of a generic gauge theory bosonic component. We show how it is possible to derive the gauge charge conservation from the invariance of the model under extra-dimensional translations and to geometrize gauge connections for spinors, thus we can introduce the matter just by free spinorial fields. Then, we present the applications to i)a pentadimensional manifold $V^{4}\otimes S^{1}$, so reproducing the original Kaluza-Klein theory, unless some extensions related to the rule of the scalar field contained in the metric and the introduction of matter by spinors with a phase dependence from the fifth coordinate, ii)a seven-dimensional manifold $V^{4}\otimes S^{1}\otimes S^{2}$, in which we geometrize the electro-weak model by introducing two spinors for any leptonic family and quark generation and a scalar field with two components with opposite hypercharge, responsible of spontaneous symmetry breaking.Comment: 37 pages, no figure

Seroprevalencia del virus de la leucemia bovina en rodeos lecheros del Departamento Iriondo, Santa Fe, Argentina

El objetivo de este trabajo fue determinar la seroprevalencia del virus de la leucemia bovina (VLB) en rodeos lecheros de la Provincia de Santa Fe. Se procesaron 747 muestras mediante la técnica de inmunodifusión en gel de agar. Se realizó un análisis chi-cuadrado para evaluar la asociación entre la categoría y la general, que fue del 79,1%, siendo la prevalencia por categorías de 82,1% para vacas, 56,2% para vaquillonas y 54,5% para toros. En el análisis estadístico se observó una asociación de seropositividad. Los resultados de prevalencia intra-predial fueron entre el 63% y el 96%. La prevalencia estadísticamente significativa entre adultos y seropositividad, fue teniendo éstos 4 veces más chances de ser seropositivos que las vaquillonas. La elevada seroprevalencia del VLB hallada, demuestra que el virus está ampliamente distribuido en los rodeos lecheros de la región sur de la Provincia de Santa Fe

On Solving the Coronal Heating Problem

This article assesses the current state of understanding of coronal heating, outlines the key elements of a comprehensive strategy for solving the problem, and warns of obstacles that must be overcome along the way.Comment: Accepted by Solar Physics; Published by Solar Physic