Measurement-based approach to entanglement generation in coupled quantum dots

Measurements provide a novel mechanism for generating the entanglement resource necessary for performing scalable quantum computation. Recently, we proposed a method for performing parity measurements in a coupled quantum dot system. In this paper we generalise this scheme and perform a comprehensive analytic and numerical study of environmental factors. We calculate the effects of possible error sources including non-ideal photon detectors, ineffective spin-selective excitation and dot distinguishability (both spatial and spectral). Furthermore, we present an experimental approach for verifying the success of the parity measurement

Genetic Locus Required for Antigenic Maturation of \u3cem\u3eRhizobium etli\u3c/em\u3e CE3 Lipopolysaccharide

Rhizobium etli modifies lipopolysaccharide (LPS) structure in response to environmental signals, such as low pH and anthocyanins. These LPS modifications result in the loss of reactivity with certain monoclonal antibodies. The same antibodies fail to recognize previously isolated R. etli mutant strain CE367, even in the absence of such environmental cues. Chemical analysis of the LPS in strain CE367 demonstrated that it lacked the terminal sugar of the wild-type O antigen, 2,3,4-tri-O-methylfucose. A 3-kb stretch of DNA, designated as lpe3, restored wild-type antigenicity when transferred into CE367. From the sequence of this DNA, five open reading frames were postulated. Site-directed mutagenesis and complementation analysis suggested that the genes were organized in at least two transcriptional units, both of which were required for the production of LPS reactive with the diagnostic antibodies. Growth in anthocyanins or at low pH did not alter the specific expression of gusA from the transposon insertion of mutant CE367, nor did the presence of multiple copies of lpe3 situated behind a strong, constitutive promoter prevent epitope changes induced by these environmental cues. Mutations of the lpe genes did not prevent normal nodule development on Phaseolus vulgaris and had very little effect on the occupation of nodules in competition with the wild-type strain

Studies of concentration and temperature dependencies of precipitation kinetics in iron-copper alloys using kinetic monte carlo and stochastic statistical simulations

The earlier-developed ab initio model and the kinetic Monte Carlo method (KMCM) are used to simulate precipitation in a number of iron-copper alloys with different copper concentrations x and temperatures T. The same simulations are also made using the improved version of the earlier-suggested stochastic statistical method (SSM). The results obtained enable us to make a number of general conclusions about the dependencies of the decomposition kinetics in Fe-Cu alloys on x and T. We also show that the SSM describes the precipitation kinetics in a fair agreement with the KMCM, and employing the SSM in conjunction with the KMCM enables us to extend the KMC simulations to the longer evolution times. The results of simulations seem to agree with available experimental data for Fe-Cu alloys within statistical errors of simulations and the scatter of experimental results. Comparison of results of simulations to experiments for some multicomponent Fe-Cu-based alloys enables us to make certain conclusions about the influence of alloying elements in these alloys on the precipitation kinetics at different stages of evolution.Comment: 18 pages, 17 postscript figures, LaTe

Electronic excitation dynamics in multichromophoric systems described via a polaron-representation master equation

We derive a many-site version of the non-Markovian time-convolutionless polaron master equation [S. Jang et al., J. Chem Phys. 129, 101104 (2008)] to describe electronic excitation dynamics in multichromophoric systems. By treating electronic and vibrational degrees of freedom in a combined frame (polaron frame), this theory is capable of interpolating between weak and strong exciton-phonon coupling and is able to account for initial non-equilibrium bath states and spatially correlated environments. Besides outlining a general expression for the expected value of any electronic system observable in the original frame, we also discuss implications of the Markovian and secular approximations highlighting that they need not hold in the untransformed frame despite being strictly satisfied in the polaron frame. The key features of the theory are illustrated using as an example a four-site subsystem of the Fenna-Mathew-Olson light-harvesting complex. For a spectral density including a localised high-energy mode, we show that oscillations of site populations may only be observed when non-equilibrium bath effects are taken into account. Furthermore, we illustrate how this formalism allows us to identify the electronic or vibrational origin of the oscillatory dynamics.Comment: 13 pages, 6 figures; minor corrections made; accepted for publication in Journal of Chemical Physic

Prospective Phase II trial of drug-eluting bead chemoembolization for liver transplant candidates with hepatocellular carcinoma and marginal hepatic reserve.

Purpose: To determine whether chemoembolization using drug-eluting beads (DEB-TACE) is safe and effective for liver transplantation candidates with liver-limited hepatocellular carcinoma (HCC) without vascular invasion and baseline hepatic dysfunction. Materials and methods: Seventeen adult liver transplantation candidates (median age 66 years, range 58-73 years; 13 men) with HCC were treated with DEB-TACE as a part of Stage 1 of a prospective single-institution Phase II trial. All patients had marginal hepatic reserve based on at least one of the following criteria: ascites (n=14), bilirubin between 3 and 6 mg/dL (n=5), AST 5-10 times upper normal limit (n=1), INR between 1.6 and 2.5 (n=4), portal vein thrombosis (n=2), and/or portosystemic shunt (n=2). Primary study objectives were safety and best observed radiographic response. Results: Thirty-seven DEB-TACE procedures were performed. Objective response rate and disease control rate were 63% and 88%, respectively. HCC progression was observed in 12 patients. Median time to progression was 5.6 months (range 0.9-13.6 months). Within 1 month following DEB-TACE, 13 patients (76%) developed grade 3 or 4 AE attributable to the procedure. Four patients (all within Milan Criteria) were transplanted (2.7-6.9 months after DEB-TACE), and 12 patients died (1.8-32 months after DEB-TACE). All deaths were due to liver failure that was either unrelated to HCC (n=5), in the setting of metastatic HCC (n=5), or in the setting of locally advanced HCC (n=2). Mortality rate at 1 month was 0%. Conclusions: DEB-TACE achieves tumor responses but carries a high risk of hepatotoxicity for liver transplant candidates with HCC and marginal hepatic reserve

Severe Hypokalemia Secondary to Distal Renal Tubular Acidosis in a Hispanic Man

Introduction: Renal tubular acidosis is a rare renal disorder that can cause severe electrolyte imbalances which can be life threatening. Case: A 21-year-old man presented to the ED on account of generalized weakness and body aches of one day duration. He reported no past medical history other than a previous episode of similar symptoms with improvement after IV hydration and electrolytes replacements about 2 months prior. He was not taking any medications and denied vomiting, diarrhea nor any significant family history. He admitted to alcohol and marijuana use. Physical examination was significant for reduced muscle power, tone, and reflexes in all extremities. He was unable to move his limbs against gravity. Admission laboratory findings revealed severe hypokalemia 1.1 mEq/L, metabolic acidosis with bicarbonate of 10.1 and EKG showed QT prolongation. Patient received a total of about 200 mEq of potassium through a central line in 24 hours with serum level of 3.7mmol/l in addition to intravenous bicarbonates with a resolution of the presenting symptoms. Discussion: The causes of hypokalemia are broad however a methodical approach can be helpful to rule out the many causes and narrow down the differential diagnosis. Distal RTA is caused by the inability of the distal renal tubule to secrete hydrogen ions due to the selective failure of activity or expression of the H+-ATPase. Conclusion: This case underscores the importance of systematic approach to the evaluation of patients with hypokalemia to uncover the cause of the underlying disease before life threatening complications occur. Our patient remains under close follow up

Population-Based Utility of van Herick Grading for Angle-Closure Detection

Primary angle-closure glaucoma accounts for half of glaucoma-related blindness worldwide with a disproportionate burden of disease found in Asian populations. The clinical reference standard for diagnosis of angle closure is gonioscopy, but van Herick (VH) grading of limbal anterior chamber depth (LACD) has been used as a screening tool, with varying sensitivities and specificities on classifying gonioscopically occludable angles reported in Chinese and other East Asian populations. A cutoff of VH grade ≤1 (modified grade ≤15%) has been found to have sensitivities ranging from 19% to 84% and specificities from 86% to 100%, whereas a higher cutoff VH grade ≤2 (modified grade ≤25%) has had sensitivities ranging from 54% to 99% and specificities from 65% to 96%. However, the efficacy of using the VH test as a screening tool in community-based screening programs to identify gonioscopically occludable angle has not been investigated. The purpose of this study was to determine the sensitivity and specificity of modified VH grading of LACD in detecting gonioscopically defined primary angle-closure suspects (PACS) among subjects screened for participation in the Zhongshan Angle Closure Prevention (ZAP) Trial in southern China

Crop type identification and spatial mapping using Sentinel-2 satellite data with focus on field-level information

Accurate monitoring of croplands helps in making decisions (for insurance claims, crop management and contingency plans) at the macro-level, especially in drylands where variability in cropping is very high owing to erratic weather conditions. Dryland cereals and grain legumes are key to ensuring the food and nutritional security of a large number of vulnerable populations living in the drylands. Reliable information on area cultivated to such crops forms part of the national accounting of food production and supply in many Asian countries, many of which are employing remote sensing tools to improve the accuracy of assessments of cultivated areas. This paper assesses the capabilities and limitations of mapping cultivated areas in the Rabi (winter) season and corresponding cropping patterns in three districts characterized by small-plot agriculture. The study used Sentinel-2 Normalized Difference Vegetation Index (NDVI) 15-day time-series at 10m resolution by employing a Spectral Matching Technique (SMT) approach. The use of SMT is based on the well-studied relationship between temporal NDVI signatures and crop phenology. The rabi season in India, dominated by non-rainy days, is best suited for the application of this method, as persistent cloud cover will hamper the availability of images necessary to generate clearly differentiating temporal signatures. Our study showed that the temporal signatures of wheat, chickpea and mustard are easily distinguishable, enabling an overall accuracy of 84%, with wheat and mustard achieving 86% and 94% accuracies, respectively. The most significant misclassifications were in irrigated areas for mustard and wheat, in small-plot mustard fields covered by trees and in fragmented chickpea areas. A comparison of district-wise national crop statistics and those obtained from this study revealed a correlation of 96%