Selective darkening of degenerate transitions for implementing quantum controlled-NOT gates

We present a theoretical analysis of the selective darkening method for implementing quantum controlled-NOT (CNOT) gates. This method, which we recently proposed and demonstrated, consists of driving two transversely-coupled quantum bits (qubits) with a driving field that is resonant with one of the two qubits. For specific relative amplitudes and phases of the driving field felt by the two qubits, one of the two transitions in the degenerate pair is darkened, or in other words, becomes forbidden by effective selection rules. At these driving conditions, the evolution of the two-qubit state realizes a CNOT gate. The gate speed is found to be limited only by the coupling energy J, which is the fundamental speed limit for any entangling gate. Numerical simulations show that at gate speeds corresponding to 0.48J and 0.07J, the gate fidelity is 99% and 99.99%, respectively, and increases further for lower gate speeds. In addition, the effect of higher-lying energy levels and weak anharmonicity is studied, as well as the scalability of the method to systems of multiple qubits. We conclude that in all these respects this method is competitive with existing schemes for creating entanglement, with the added advantages of being applicable for qubits operating at fixed frequencies (either by design or for exploitation of coherence sweet-spots) and having the simplicity of microwave-only operation.Comment: 25 pages, 5 figure

A novel stepwise micro-TESE approach in non obstructive azoospermia

Background: The purpose of the study was to investigate whether micro-TESE can improve sperm retrieval rate (SRR) compared to conventional single TESE biopsy on the same testicle or to contralateral multiple TESE, by employing a novel stepwise micro-TESE approach in a population of poor prognosis patients with non-obstructive azoospermia (NOA). Methods: Sixty-four poor prognosis NOA men undergoing surgical testicular sperm retrieval for ICSI, from March 2007 to April 2013, were included in this study. Patients inclusion criteria were a) previous unsuccessful TESE, b) unfavorable histology (SCOS, MA, sclerahyalinosis), c) Klinefelter syndrome. We employed a stepwise micro-TESE consisting three-steps: 1) single conventional TESE biopsy; 2) micro-TESE on the same testis; 3) contralateral multiple TESE. Results: SRR was 28.1 % (18/64). Sperm was obtained in both the initial single conventional TESE and in the following micro-TESE. The positive or negative sperm retrieval was further confirmed by a contralateral multiple TESE, when performed. No significant pre-operative predictors of sperm retrieval, including patients’ age, previous negative TESE or serological markers (LH, FSH, inhibin B), were observed at univariate or multivariate analysis. Micro-TESE (step 2) did not improve sperm retrieval as compared to single TESE biopsy on the same testicle (step 1) or multiple contralateral TESE (step 3). Conclusions: Stepwise micro-TESE could represent an optimal approach for sperm retrieval in NOA men. In our view, it should be offered to NOA patients in order to gradually increase surgical invasiveness, when necessary. Stepwise micro-TESE might also reduce the costs, time and efforts involved in surgery

Comportamento agronômico de uvas de mesa no Vale do São Francisco.

O presente trabalho tem como objetivo avaliar 122 genótipos de uvas de mesa, visando selecionar aqueles com características superiores para serem recomendados para cultivo comercial ou para serem utilizados em programas de melhoramento genético

The current progress of the ALICE Ring Imaging Cherenkov Detector

Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface. Finally we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy ions collisions, hadrons up to 30 GeV/c.Comment: Presented at the Imaging-2006 Conference, Stockholm, Sweden, June 200

Central pancreatectomy: comparison of results according to the type of anastomosis

INTRODUCTION: The mild pancreatic tumors are more and more treated by central pancreatectomy (CP) in alternative with the widened pancreatectomies. Indeed, their morbidity is lesser but they are however burdened by a rate of important postoperative fistulas. The purpose of our study is to compare pancreatico-jejunal anastomosis and pancreatico-gastric anastomosis. METHODS: This work was realized in a bicentric retrospective way. Twenty-five CP were included and classified according to two groups according to the pancreatic anastomosis (group 1 for pancreatico-jejunal anastomosis and group 2 for the pancreatico-gastric anastomosis). CP was realized according to a protocol standardized in both centers and the complications were classified according to the classification of Clavien and Dindo and the fistulas according to the classification of Bassi. RESULTS: Both groups were comparable. The duration operating and the blood losses were equivalent in both groups. There was a significant difference (P=0,014) as regards the rate of fistula. The pancreatico-gastric anastomosis complicated more often of a low-grade fistula. However, in both groups, the treatment was mainly medical. Our results were comparable with those found in the literature and confirmed the advantages of the CP with regard to the cephalic duodeno-pancreatectomy (DPC) or to the distal pancreatectomy (DP). However, in the literature, a meta-analysis did not report difference between both types of anastomosis but this one concerned only the DPC. CONCLUSIONS: This work showed a less important incidence of low-grade fistula after pancreatico-jejunal anastomosis in the fall of a PM. This result should be confirmed by a later study on a more important sample of PM

Revegetação de solos degradados.

Quebra de dormência das sementes; Inoculação das sementes; Obtenção do inoculante; Inoculação com fungos micorrízicos; Produção de mudas; Plantio no campo; Experiências de campo.bitstream/CNPAB-2010/27134/1/cot009.pd

Embrapa Tabuleiros Costeiros produz rebanho de ovelhas Santa Inês com maior prolificidade.

Apesar do crescimento e do reconhecido valor sócio-econômico da atividade, a ovinocultura brasileira ainda apresenta, em muitos casos, reduzidos índices de produtividade em conseqüência do baixo desempenho reprodutivo e produtivo dos rebanhos. Entende-se como eficiência reprodutiva a somatória da fertilidade, da prolificidade e da sobrevivência dos cordeiros no sistema de produção. O número de cordeiros nascidos por ovelha acasalada é resultado da fertilidade e da prolificidade, e a sobrevivência desses cordeiros está principalmente na dependência da alimentação pré-parto, da habilidade materna e do manejo adequado da mãe e do cordeiro pós-parto. A otimização da eficiência reprodutiva depende do uso de melhores condições alimentares e de raças, cruzamentos ou animais mais eficientes para a produção sendo que a genética e a alimentação são as bases fundamentais do sistema tendo reflexo direto sobre a reprodução e podendo comprometer o seu desempenho (Pilar et al., 2002).bitstream/item/123112/1/Embrapa-Tabuleiros.pd

The scientific and technological trajectories of four Latin American countries: Mexico, Costa Rica, Argentina, and Brazil

This paper introduces the differences and similarities of interactions between science and technology (S&T) among four Latin American countries: Argentina, Brazil, Costa Rica and Mexico. Through the analysis of articles and patents data as well as the elaboration of global matrices and national three-dimensional matrices, it was possible to observe the recent trajectory of the scientific and technological production of countries. The results indicate that the Latin American countries have a similar pattern regarding their scientific and technological structure and they are part of a regime characterized by immature National Systems of Innovation (NSI).Latin American countries, science and technology interaction, national systems of innovation