Atomic quantum superposition state generation via optical probing

We analyze the performance of a protocol to prepare an atomic ensemble in a superposition of two macroscopically distinguishable states. The protocol relies on conditional measurements performed on a light field, which interacts with the atoms inside an optical cavity prior to detection, and we investigate cavity enhanced probing with continuous beams of both coherent and squeezed light. The stochastic master equations used in the analysis are expressed in terms of the Hamiltonian of the probed system and the interaction between the probed system and the probe field and are thus quite generally applicable.Comment: 10 pages, 9 figure

Asymmetric double-well potential for single atom interferometry

We consider the evolution of a single-atom wavefunction in a time-dependent double-well interferometer in the presence of a spatially asymmetric potential. We examine a case where a single trapping potential is split into an asymmetric double well and then recombined again. The interferometer involves a measurement of the first excited state population as a sensitive measure of the asymmetric potential. Based on a two-mode approximation a Bloch vector model provides a simple and satisfactory description of the dynamical evolution. We discuss the roles of adiabaticity and asymmetry in the double-well interferometer. The Bloch model allows us to account for the effects of asymmetry on the excited state population throughout the interferometric process and to choose the appropriate splitting, holding and recombination periods in order to maximize the output signal. We also compare the outcomes of the Bloch vector model with the results of numerical simulations of the multi-state time-dependent Schroedinger equation.Comment: 9 pages, 6 figure

Survival analysis following enucleation for uveal melanoma

OBJECTIVES: To determine survival outcomes following enucleation for uveal melanoma. To compare these outcomes with the 8th edition AJCC classification and determine the influence of cytogenetics, using Fluorescent in situ Hybridisation (FISH), on survival. To determine whether failure to gain sufficient sample for cytogenetics using Fine Needle Aspiration Biopsy (FNAB) correlates with survival. SUBJECTS/METHODS: All patients undergoing primary enucleation for uveal melanoma at Moorfields Eye Hospital between 2012 and 2015 were included. Clinical, pathological, cytological and survival data were analysed for all patients. RESULTS: In total, 155 subjects were included. Mean age at enucleation was 65.9 years (SD 14.13). 88 (56.8%) patients died at a mean of three (SD 1.9) years following enucleation. Of these, 52 (33.5%) died from metastatic melanoma, 16 (10.3%) from other causes and 20 (12.9%) causes of death were unknown. Cumulative incidence analysis demonstrated AJCC grade, chromosome 8q gain and monosomy three all predict metastatic mortality. The greatest 5-year mortality rate (62%, SD10.1%) was in those with both chromosome abnormalities and AJCC stage III (Stage IV patients excluded due to low numbers). Largest basal diameter and chromosome status, both independently (p = 0.02 and p < 0.001) predicted metastatic mortality on multivariable regression analysis. Those who had an insufficient sample of cells gained during FNAB (n = 16) had no different prognosis. CONCLUSIONS: This study confirms, in this population, the poor survival of patients enucleated for uveal melanomas. It confirms the prognostic utility of adding AJCC grade to cytogenetic information. It demonstrates that the lack of sample in patients undergoing FNAB is not related to prognosis

Decision making and management of gliomas: practical considerations

Over the last decade, diagnostic options and introduction of novel treatments have expanded the armamentarium in the management of malignant glioma. Combined chemoradiotherapy has become the standard of care in glioblastoma up to the age of 70 years, while treatment in elderly patients or with lower grade glioma is less well defined. Molecular markers define different disease subtypes and allow for adapted treatment selection. This review focuses on simple questions arising in the daily management of patient

Errors in quantum optimal control and strategy for the search of easily implementable control pulses

We introduce a new approach to assess the error of control problems we aim to optimize. The method offers a strategy to define new control pulses that are not necessarily optimal but still able to yield an error not larger than some fixed a priori threshold, and therefore provide control pulses that might be more amenable for an experimental implementation. The formalism is applied to an exactly solvable model and to the Landau-Zener model, whose optimal control problem is solvable only numerically. The presented method is of importance for applications where a high degree of controllability of the dynamics of quantum systems is required.Comment: 13 pages, 3 figure

Adjuvant External Beam Radiotherapy Following Enucleation of Eyes With Extraocular Extension From Uveal Melanoma

PURPOSE: To report local disease control and all-cause mortality in patients with extraocular extension (EOE) of uveal melanoma undergoing enucleation followed by observation or external beam radiotherapy (EBRT). METHODS: Charts of patients enucleated between January 1, 1997 and December 31, 2019, with histopathological evidence of EOE of uveal melanoma were reviewed. RESULTS: The cohort comprised 51 patients with a mean age of 67 ± 15 years, 22 (43%) of whom underwent adjuvant postenucleation EBRT. Risk factors for metastasis included presence of epithelioid cells (29/45; 88%), closed loops (20/43; 47%), monosomy 3 (16/25; 64%), and gain of 8q (20/22; 91%). Patients undergoing EBRT had more extensive EOE (median: 5.1 mm vs. 2.6 mm, p = 0.008) and surgical excision was less likely to be histologically complete (2/20; 10% vs. 14/25; 56%, p = 0.002). Local side effects following EBRT were seen in 64% (14/22). At latest follow up, 59% of patients (30/51) were alive, with a median follow up of 1.8 years (interquartile range: 2.9; range: 0.1-6.5]. By Kaplan-Meier survival analysis, the 5- and 10-year overall survival rates were 56% and 12%, respectively. There was no difference in all-cause mortality between those receiving adjuvant EBRT and those who were observed (log rank, p = 0.273). No cases of orbital recurrence were documented. CONCLUSIONS: Orbital EBRT causes significant morbidity. Cases with relatively small EOE undergoing enucleation can be safely observed, without adjuvant EBRT. Multicenter studies are required to better assess the role of EBRT when EOE is more extensive

Characterization of meloidogyne species from irrigated rice in southern Brazil.

Edição dos Proceedings do 6th International Congress of Nematology, Cape Town, South Africa, May 2014

Comunidades de minhocas em diferentes tipos de uso do solo localizados na Área de Proteção Ambiental da Serra da Mantiqueira - MG.

5° ELAETAO

Interaction-based quantum metrology showing scaling beyond the Heisenberg limit

Quantum metrology studies the use of entanglement and other quantum resources to improve precision measurement. An interferometer using N independent particles to measure a parameter X can achieve at best the "standard quantum limit" (SQL) of sensitivity {\delta}X \propto N^{-1/2}. The same interferometer using N entangled particles can achieve in principle the "Heisenberg limit" {\delta}X \propto N^{-1}, using exotic states. Recent theoretical work argues that interactions among particles may be a valuable resource for quantum metrology, allowing scaling beyond the Heisenberg limit. Specifically, a k-particle interaction will produce sensitivity {\delta}X \propto N^{-k} with appropriate entangled states and {\delta}X \propto N^{-(k-1/2)} even without entanglement. Here we demonstrate this "super-Heisenberg" scaling in a nonlinear, non-destructive measurement of the magnetisation of an atomic ensemble. We use fast optical nonlinearities to generate a pairwise photon-photon interaction (k = 2) while preserving quantum-noise-limited performance, to produce {\delta}X \propto N^{-3/2}. We observe super-Heisenberg scaling over two orders of magnitude in N, limited at large N by higher-order nonlinear effects, in good agreement with theory. For a measurement of limited duration, super-Heisenberg scaling allows the nonlinear measurement to overtake in sensitivity a comparable linear measurement with the same number of photons. In other scenarios, however, higher-order nonlinearities prevent this crossover from occurring, reflecting the subtle relationship of scaling to sensitivity in nonlinear systems. This work shows that inter-particle interactions can improve sensitivity in a quantum-limited measurement, and introduces a fundamentally new resource for quantum metrology

Impact of dense-water flow over a sloping bottom on open-sea circulation: Laboratory experiments and an Ionian Sea (Mediterranean) example

The North Ionian Gyre (NIG) displays prominent inversions on decadal scales. We investigate the role of internal forcing induced by changes in the horizontal pressure gradient due to the varying density of Adriatic Deep Water (AdDW), which spreads into the deep layers of the northern Ionian Sea. In turn, the AdDW density fluctuates according to the circulation of the NIG through a feedback mechanism known as the bimodal oscillating system. We set up laboratory experiments with a two-layer ambient fluid in a circular rotating tank, where densities of 1000 and 1015ĝ€¯kgĝ€¯m-3 characterize the upper and lower layers, respectively. From the potential vorticity evolution during the dense-water outflow from a marginal sea, we analyze the response of the open-sea circulation to the along-slope dense-water flow. In addition, we show some features of the cyclonic and anticyclonic eddies that form in the upper layer over the slope area. We illustrate the outcome of the experiments of varying density and varying discharge rates associated with dense-water injection. When the density is high (1020ĝ€¯kgĝ€¯m-3) and the discharge is large, the kinetic energy of the mean flow is stronger than the eddy kinetic energy. Conversely, when the density is lower (1010ĝ€¯kgĝ€¯m-3) and the discharge is reduced, vortices are more energetic than the mean flow - that is, the eddy kinetic energy is larger than the kinetic energy of the mean flow. In general, over the slope, following the onset of dense-water injection, the cyclonic vorticity associated with current shear develops in the upper layer. The vorticity behaves in a two-layer fashion, thereby becoming anticyclonic in the lower layer of the slope area. Concurrently, over the deep flat-bottom portion of the basin, a large-scale anticyclonic gyre forms in the upper layer extending partly toward a sloping rim. The density record shows the rise of the pycnocline due to the dense-water sinking toward the flat-bottom portion of the tank. We show that the rate of increase in the anticyclonic potential vorticity is proportional to the rate of the rise of the interface, namely to the rate of decrease in the upper-layer thickness (i.e., the upper-layer squeezing). The comparison of laboratory experiments with the Ionian Sea is made for a situation when the sudden switch from cyclonic to anticyclonic basin-wide circulation took place following extremely dense Adriatic water overflow after the harsh winter in 2012. We show how similar the temporal evolution and the vertical structure are in both laboratory and oceanic conditions. The demonstrated similarity further supports the assertion that the wind-stress curl over the Ionian Sea is not of paramount importance in generating basin-wide circulation inversions compared with the internal forcing