Entanglement of Atomic Qubits using an Optical Frequency Comb

We demonstrate the use of an optical frequency comb to coherently control and entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used to efficiently and coherently transfer population between electronic and vibrational states of trapped atomic ions and implement an entangling quantum logic gate with high fidelity. This technique can be extended to the high field regime where operations can be performed faster than the trap frequency. This general approach can be applied to more complex quantum systems, such as large collections of interacting atoms or molecules.Comment: 4 pages, 5 figure

Dynamical Susceptibility in KDP-type Crysals above and below Tc II

The path probability method (PPM) in the tetrahedron-cactus approximation is applied to the Slater-Takagi model with dipole-dipole interaction for KH2PO4-type hydrogen-bonded ferroelectric crystals in order to derive a small dip structure in the real part of dynamical susceptibility observed at the transition temperature Tc. The dip structure can be ascribed to finite relaxation times of electric dipole moments responsible for the first order transition with contrast to the critical slowing down in the second order transition. The light scattering intensity which is related to the imaginary part of dynamical susceptibility is also calculated above and below the transition temperature and the obtained central peak structure is consistent with polarization fluctuation modes in Raman scattering experiments.Comment: 8 pages, 11 figure

Analysis of technology requirements and potential demand for general aviation avionics systems for operation in the 1980's

Avionics systems are identified which promise to reduce economic constraints and provide significant improvements in performance, operational capability and utility for general aviation aircraft in the 1980's

Fourier-transform electrospray instrumentation for tandem high-resolution mass spectrometry of large molecules

AbstractMass spectrometry instrumentation providing unit resolution and 10-ppm mass accuracy for molecules larger than 10 kDa was first reported in 1991. This instrumentation has now been improved with a 6.2-T magnet replacing that of 2.8 T, a more efficient vacuum system, ion injection with controlled ion kinetic energies, accumulated ion trapping with an open-cylindrical ion cell, acquisition of 2M data points, and updated electrospray apparatus. The resulting capabilities include resolving power of 5 × 105 for a 29-kDa protein, less than 1-ppm mass measuring error, and dissociation of protein molecular ions to produce dozens of fragment ions whose exact masses can be identified from their mass-to-charge ratio values and isotopic peak spacing

Management of multi- and extensively drug-resistant tuberculosis in Ukraine: how well are we doing?

Setting: A tertiary care facility in Ukraine, a high multi- and extensively drug-resistant tuberculosis (MDR/XDR-TB) burden country. Objectives: To assess the management and treatment outcomes of MDR, pre-XDR-TB and XDR-TB. Design: Cohort study using programme data, 2006–2011. Results: Of 484 individuals with drug-resistant TB, 217 (45%) had MDR-, 153 (32%) pre-XDR- and 114 (24%) XDR-TB. Of all resistant types completing the intensive phase of treatment, 322 (67%) were alive and had culture converted. This included 157 (72%) with MDR- and 61 (54%) with XDR-TB. At the end of the continuation phase of treatment, 106 (22%) had treatment success and 378 (78%) had unfavourable outcomes, including 110 (23%) failures, 21 (4%) deaths, 71 (15%) losses to follow-up and 176 (36%) with an unknown outcome. This was associated with more than one lung cavity being affected, a history of treatment with second-line anti-tuberculosis drugs, poor adherence and XDR-TB. A total of 226 (47%) patients reported at least one adverse drug reaction, the most common being gastrointestinal and vestibular toxicity. Conclusion: Outcomes of MDR- and XDR-TB were satisfactory in the intensive phase; however, this was not sustained during the ambulatory period. If we are to do better, urgent measures are needed to improve ambulatory management, including making safer, shorter and more effective drug regimens available

Oxygen-dependent histone lysine demethylase 4 restricts hepatitis B virus replication

Mammalian cells have evolved strategies to regulate gene expression when oxygen is limited. Hypoxia-inducible factors (HIF) are the major transcriptional regulators of host gene expression. We previously reported that HIFs bind and activate hepatitis B virus (HBV) DNA transcription under low oxygen conditions; however, the global cellular response to low oxygen is mediated by a family of oxygenases that work in concert with HIFs. Recent studies have identified a role for chromatin modifiers in sensing cellular oxygen and orchestrating transcriptional responses, but their role in the HBV life cycle is as yet undefined. We demonstrated that histone lysine demethylase 4 (KDM4) can restrict HBV, and pharmacological or oxygen-mediated inhibition of the demethylase increases viral RNAs derived from both episomal and integrated copies of the viral genome. Sequencing studies demonstrated that KDM4 is a major regulator of the hepatic transcriptome, which defines hepatocellular permissivity to HBV infection. We propose a model where HBV exploits cellular oxygen sensors to replicate and persist in the liver. Understanding oxygen-dependent pathways that regulate HBV infection will facilitate the development of physiologically relevant cell-based models that support efficient HBV replication

Achievement Goal

Achievement goals are self-regulatory commitments that provide direction to individuals as they interpret and respond to competence-relevant situations. Four types of achievement goals have been the primary focus of the literature: Masteryapproach goals (master a task; improve over time), performance-approach goals (outperform others), mastery-avoidance goals (not fall short of mastering a task; not decline over time), and performance-avoidance goals (not be outperformed by others)