Canonical circuit quantization with linear nonreciprocal devices

Nonreciprocal devices effectively mimic the breaking of time-reversal symmetry for the subspace of dynamical variables that they couple, and can be used to create chiral information processing networks. We study the systematic inclusion of ideal gyrators and circulators into Lagrangian and Hamiltonian descriptions of lumped-element electrical networks. The proposed theory is of wide applicability in general nonreciprocal networks on the quantum regime. We apply it to pedagogical and pathological examples of circuits containing Josephson junctions and ideal nonreciprocal elements described by admittance matrices, and compare it with the more involved treatment of circuits based on nonreciprocal devices characterized by impedance or scattering matrices. Finally, we discuss the dual quantization of circuits containing phase-slip junctions and nonreciprocal devices.Comment: 12 pages, 4 figures; changes made to match the accepted version in PR

Spontaneous Intracranial Hypotension and Multi-Level Cervical and Lumbar Epidural Blood Patches: A Case Report

Spontaneous intracranial hypotension (SIH) is a neurologic condition where the intracranial pressure is reduced due to a loss of cerebrospinal fluid from its reservoir, the intrathecal space, to surrounding tissues. It is commonly characterized by an incapacitating headache, phono-photophobia, nausea, and vomiting, commonly refractory to medical treatment and requires further investigation. We describe the case of a healthy young man who presented to the emergency room with a postural headache, accompanied by nausea, vomiting, and phono-photophobia. Brain computed tomography (CT) imaging study was unremarkable and he was initially treated symptomatically. Because of persisting pain even on medical treatment, additional imaging studies, including a myelo-CT scan, were performed and a diagnosis of multi-level cerebrospinal fluid fistulas was made. To treat the underlying cause, a first epidural blood patch (EBP) was initially performed at C7-T1 with 20 mL of autologous blood, but failed to provide complete symptomatic relief. Months later, a second EBP was conducted at C6-C7 with higher volume (30 mL) but as in the first EBP this procedure too did not result in total resolution of the headache and accompanying symptoms. Since there was no surgical indication from Orthopedics and Neurosurgery and the symptoms persisted, a third EBP was carried out, this time at a lumbar level (L2-L3) with infusion of 60 mL of blood so the upper dorsal and cervical epidural space was reached. This resulted in a better symptom relief, allowing the patient to now carry out his normal activities with only residual pain. The need for repeat procedures is one of the pitfalls of the blood patching technique. If possible, it should be performed at the level of the documented fistula, but always with safety in mind and by experienced hands, especially when cervical levels are concerned. A consensus has not been reached regarding the blood volume to be administered; however, any discomfort or pain reported by the patient should be seen as warning sign and the procedure should be interrupted. Although not being a perfect solution, EBP can completely or partially resolve SIH symptoms, without the need for surgical intervention.info:eu-repo/semantics/publishedVersio

Hamiltonian description of singular Lagrangian systems with spontaneously broken time translation symmetry

Shapere and Wilczek recently found some singular Lagrangian systems which spontaneously breaks time translation symmetry. The common feature of their models is that the energy functions are multivalued in terms of the canonical phase space variables and the symmetry breaking ground states are all located at the brunching point singularities. By enlarging the phase space and making use of Dirac's theory on constrained Hamiltonian systems, we present the Hamiltonian description of some of the models discussed by Shapere and Wilczek and found that both the multivaluedness and the brunching point singularities can be avoided, while the spontaneous breaking oftime translation becomes more transparent. It is also shown that the breaking of time translation is always accompanied by the breaking of time reversal.Comment: 13 page

VO2max test is not altered by a submaximum exercise

INTRODUCTION: The Maximum Oxygen Consumption (VO2max) and Ventilatory anaerobic threshold (VT), is measured using progressive exercise protocol until exhaustion, these results can be affected by a previous submaximum exercise. PURPOSE: The purpose of this study was evaluate the reproducibility of maximum effort test after a submaximum exercise. METHODS: 19 subjects (mean ± SD; age, 21.8±2.5 years; body mass, 71.0±10.6 and height, 175.2±8.1) participated in this study. During two days of assessment separately for at least 24h recovery subjects performed the following tests: Day 1 a maximum effort test and a submaximum exercise at 80% of VO2max. Day 2 the order of the tests performed on day 1 was reversed. RESULTS: No significant differences were found in the VO2max or ventilatory thresholds determined in both tests of maximum effort. (VO2max 54.2 ± 6.8vs 55.1 ± 6.4 (ml·kg-1·min-1), ICC; 0.91, CV; 3.9 ± 2.1); (VO2 RCT 45.6 ± 6.4vs 45.9 ± 5.7 (ml·kg-1·min-1) ICC; 0.96, CV; 3.0 ± 2.1)( VO2 VT 35.6 ± 4.7vs 35.6 ± 4.7 (ml·kg-1·min-1) ICC; 0.87, CV; 4.9 ± 3.9). CONCLUSION: The results of the present study showed a high reproducibility of the data obtained when maximum effort test is assessed (i.e., VO2max and ventilatory threshold), regardless the submaximum exercise

PWM digital configurable para simples proyectos

This paper presents the software implementation of an adjustable PWM (Pulse Width Modulator) prototype, developed in Verilog code, which functions as a training tool at the undergraduate level, or for the development of small projects. At the schematic level, the prototype presents the main module called PWM which integrates three modules (frequency, useful cycle, and display), as a complement to carry out results under the conditions specified in the functional profile. The base module integrates combinational and sequential circuits, i.e. counters, comparators, flip flops, function generators, etc. The final results obtained by simulation show the expected behavior in terms of frequency setting, duty cycle, and display.Este artículo presenta la implementación, en cuanto a software, de un prototipo de PWM (Modulador por Ancho de Pulso) ajustable, desarrollado en código Verilog, que funcione como herramienta de formación en el ámbito de pregrado, o el desarrollo de pequeños proyectos. En cuanto a esquema, el prototipo presenta un módulo principal llamado PWM el cual integra tres módulos (frecuencia, ciclo útil y display), como complemento para llevar a cabo resultados bajo las condiciones especificadas en el perfil funcional. La base de los módulos integra circuitos combinacionales y secuenciales, es decir contadores, comparadores, Flip Flops, generadores de funciones, etc. Los resultados finales obtenidos por simulación muestran el comportamiento esperado en cuanto a ajuste de frecuencia, ciclo útil y visualización

Effects of Selective Deletion of Tyrosine Hydroxylase from Kisspeptin Cells on Puberty and Reproduction in Male and Female Mice.

The neuropeptide kisspeptin, encoded by Kiss1, regulates reproduction by stimulating GnRH secretion. Kiss1-syntheizing neurons reside primarily in the hypothalamic anteroventral periventricular (AVPV/PeN) and arcuate (ARC) nuclei. AVPV/PeN Kiss1 neurons are sexually dimorphic, with females expressing more Kiss1 than males, and participate in estradiol (E2)-induced positive feedback control of GnRH secretion. In mice, most AVPV/PeN Kiss1 cells coexpress tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis (in this case, dopamine). Dopamine treatment can inhibit GnRH neurons, but the function of dopamine signaling arising specifically from AVPV/PeN Kiss1 cells is unknown. We generated a novel TH flox mouse and used Cre-Lox technology to selectively ablate TH specifically from Kiss1 cells. We then examined the effects of selective TH knock-out on puberty and reproduction in both sexes. In control mice, 90% of AVPV/PeN Kiss1 neurons coexpressed TH, whereas in mice lacking TH exclusively in Kiss1 cells (termed Kiss THKOs), TH was successfully absent from virtually all Kiss1 cells. Despite this absence of TH, both female and male Kiss THKOs displayed normal body weights, puberty onset, and basal gonadotropin levels in adulthood, although testosterone (T) was significantly elevated in adult male Kiss THKOs. The E2-induced LH surge was unaffected in Kiss THKO females, and neuronal activation status of kisspeptin and GnRH cells was also normal. Supporting this, fertility and fecundity were normal in Kiss THKOs of both sexes. Thus, despite high colocalization of TH and Kiss1 in the AVPV/PeN, dopamine produced in these cells is not required for puberty or reproduction, and its function remains unknown

Perpendicular momentum injection by lower hybrid wave in a tokamak

The injection of lower hybrid waves for current drive into a tokamak affects the profile of intrinsic rotation. In this article, the momentum deposition by the lower hybrid wave on the electrons is studied. Due to the increase in the poloidal momentum of the wave as it propagates into the tokamak, the parallel momentum of the wave increases considerably. The change of the perpendicular momentum of the wave is such that the toroidal angular momentum of the wave is conserved. If the perpendicular momentum transfer via electron Landau damping is ignored, the transfer of the toroidal angular momentum to the plasma will be larger than the injected toroidal angular momentum. A proper quasilinear treatment proves that both perpendicular and parallel momentum are transferred to the electrons. The toroidal angular momentum of the electrons is then transferred to the ions via different mechanisms for the parallel and perpendicular momentum. The perpendicular momentum is transferred to ions through an outward radial electron pinch, while the parallel momentum is transferred through collisions.Comment: 22 pages, 4 figure