Tensorial dynamics on the space of quantum states

A geometric description of the space of states of a finite-dimensional quantum system and of the Markovian evolution associated with the Kossakowski-Lindblad operator is presented. This geometric setting is based on two composition laws on the space of observables defined by a pair of contravariant tensor fields. The first one is a Poisson tensor field that encodes the commutator product and allows us to develop a Hamiltonian mechanics. The other tensor field is symmetric, encodes the Jordan product and provides the variances and covariances of measures associated with the observables. This tensorial formulation of quantum systems is able to describe, in a natural way, the Markovian dynamical evolution as a vector field on the space of states. Therefore, it is possible to consider dynamical effects on non-linear physical quantities, such as entropies, purity and concurrence. In particular, in this work the tensorial formulation is used to consider the dynamical evolution of the symmetric and skew-symmetric tensors and to read off the corresponding limits as giving rise to a contraction of the initial Jordan and Lie products.Comment: 31 pages, 2 figures. Minor correction

Preoperative digital three-dimensional planning for rhinoplasty

BACKGROUND: This report describes preoperative digital planning for rhinoplasty using a new three-dimensional (3D) radiologic viewer that allows both patients and surgeons to visualize on a common monitor the 3D real aspect of the nose in its inner and outer sides. METHODS: In the period 2002 to 2008, 210 patients underwent rhinoplasty procedures in the authors' clinic. The patients were randomly divided into three groups according to the type of preoperative planning used: photos only, a simulated result by Adobe Photoshop, or the 3D radiologic viewer. The parameters evaluated included the number of patients that underwent surgery after the first consultation, the number of patients who asked for a reintervention, patient satisfaction (according to a test given to the patients 12 months postoperatively), the surgical time required for a functional intervention, and the improvement in nasal function by postoperative rhinomanometry and subjective evaluation. RESULTS: Computer-aided technologies led to a higher number of patients deciding to undergo a rhinoplasty. Simulation of the postoperative results was not as useful in the postoperative period due to the higher number of reintervention requests. CONCLUSION: The patients undergoing rhinoplasties preferred new technologies in the preoperative period. The advantages of using the 3D radiologic viewer included improved preoperative planning, reduction in intraoperative stress, a higher number of patients undergoing surgery, reduction in postoperative surgical corrections, reduction in surgical time for the functional intervention, a higher rate of improvement in nasal function, a higher percentage of postoperative satisfaction, and reduced costs

Assessing the Left Ventricular Systolic Function at the Bedside: The Role of Transpulmonary Thermodilution-Derived Indices

Evaluating the systolic function of the left ventricle (LV) is important in the hemodynamic management of the critically ill patients with circulatory failure. Echocardiography is considered the standard monitor for estimating the LV function at the bedside in the intensive care unit. However, it requires a trained operator and is not a real-time monitoring tool. For monitoring of the systolic function, the pulmonary artery catheter has been the gold standard for a long time. However, now there are alternatives to this device, with transpulmonary thermodilution being one of them. This paper provides an overview of the usefulness of the transpulmonary thermodilution-derived indices for assessing systolic function at the bedside

Characterization of the Hamamatsu S8664 Avalanche Photodiode for X-Ray and VUV-light detection

We present the first operation of the Avalanche Photodiode (APD) from Hamamatsu to xenon scintillation light and to direct X-rays of 22.1 keV and 5.9 keV. A large non-linear response was observed for the direct X-ray detection. At 415 V APD bias voltage it was of about 30 % for 22.1 keV and about 45 % for 5.9 keV. The quantum efficiency for 172 nm photons has been measured to be 69 +/- 15 %.Comment: 11 pages, 3 figures, submitted to Elsevie

Effect of formalin treatment on the oxygen consumption rate of young Mediterranean yellowtail Seriola dumerili (Risso, 1810)

The effect of formalin treatment (300 ppm) administered in an open bath circulator on the oxygen consumption rate of young, 1.5 kg Seriola dumerili (Risso, 1810) was studied. At the temperature range used (19.7-25.8 ºC), this formalin treatment, as applied under the conditions described here, does not seem to affect oxygen consumption rate or oxygen concentration in the water; therefore, it can be administered without supplemental oxygen supply. Given the known positive effect of formalin treatment on the culture of this species, its periodical use appears advisable; however, the potential occurrence of occasional toxicity episodes, due to reasons as yet unclarified, must be taken into account.Se ha estudiado el efecto del tratamiento con formol, a 300 ppm y administrado en baño con circuito abierto, sobre el consumo de oxígeno de juveniles de Seriola dumerili (Risso, 1810) de alrededor de 1,5 kg de peso. En el rango de temperaturas utilizado (19,7-25,8 °C), el tratamiento con formol en las condiciones descritas en este estudio no parece afectar al consumo de oxígeno ni a la concentración de oxígeno del agua, por lo que puede realizarse sin aporte suplementario de oxígeno. Dados los efectos positivos que tiene el tratamiento con formol en el cultivo de esta especie, parece recomendable su aplicación periódica, aunque siempre deben tenerse en cuenta eventuales episodios puntuales de toxicidad por motivos aun no aclarados.Instituto Español de OceanografíaVersión de editor