A high flux source of cold strontium atoms

We describe an experimental apparatus capable of achieving a high loading rate of strontium atoms in a magneto-optical trap operating in a high vacuum environment. A key innovation of this setup is a two dimensional magneto-optical trap deflector located after a Zeeman slower. We find a loading rate of 6x10^9/s whereas the lifetime of the magnetically trapped atoms in the 3P2 state is 54s.Comment: 12 pages, 16 figure

Predictors of the Extent of Carotid Atherosclerosis in Patients Treated with Radiotherapy for Nasopharyngeal Carcinoma

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Residential Proximity to Freeways is Associated with Uncontrolled Asthma in Inner-City Hispanic Children and Adolescents

Background. Proximity to heavy traffic has been linked to increased asthma severity. However, it is unknown whether exposure to heavy traffic is associated with the ability to maintain asthma control. Objectives. This study examines whether exposure to heavy traffic is associated with the ability to maintain asthma control in inner-city children. Methods. 756 inner-city asthmatic Hispanic children were followed for one year in a pediatric asthma management program (Breathmobile). At each scheduled visit, asthma specialist tracked patients' asthma severity and managed their asthma based on the NAEPP guidelines. The patients' residential distance from the nearest freeway was calculated based on residential address at study entry. Distance to nearest freeway was used as a surrogate marker for high exposure from traffic-related air pollutants. Results. Patients who lived near a freeway were significantly more likely to have asthma that was not well controlled (P = .03). Patients with intermittent and mild baseline severity have a two-fold increased risk of having asthma that is uncontrolled if they lived <2 miles from a freeway (OR = 2.2, P = .04). Conclusion. In children with asthma, residential proximity to freeways is associated with uncontrolled asthma

Observations of Spontaneous Raman Scattering in Silicon Slow-light Photonic Crystal Waveguides

We report the observations of spontaneous Raman scattering in silicon photonic crystal waveguides. Continuous-wave measurements of Stokes emission for both wavelength and power dependence is reported in single line-defect waveguides in hexagonal lattice photonic crystal silicon membranes. By utilizing the Bragg gap edge dispersion of the TM-like mode for pump enhancement and the TE-like fundamental mode-onset for Stokes enhancement, the Stokes emission was observed to increase by up to five times in the region of slow group velocity. The results show explicit nonlinear enhancement in a silicon photonic crystal slow-light waveguide device.Comment: 12 pages, 4 figure

Security proof of a three-state quantum key distribution protocol without rotational symmetry

Standard security proofs of quantum key distribution (QKD) protocols often rely on symmetry arguments. In this paper, we prove the security of a three-state protocol that does not possess rotational symmetry. The three-state QKD protocol we consider involves three qubit states, where the first two states, |0_z> and |1_z>, can contribute to key generation and the third state, |+>=(|0_z>+|1_z>)/\sqrt{2}, is for channel estimation. This protocol has been proposed and implemented experimentally in some frequency-based QKD systems where the three states can be prepared easily. Thus, by founding on the security of this three-state protocol, we prove that these QKD schemes are, in fact, unconditionally secure against any attacks allowed by quantum mechanics. The main task in our proof is to upper bound the phase error rate of the qubits given the bit error rates observed. Unconditional security can then be proved not only for the ideal case of a single-photon source and perfect detectors, but also for the realistic case of a phase-randomized weak coherent light source and imperfect threshold detectors. Our result on the phase error rate upper bound is independent of the loss in the channel. Also, we compare the three-state protocol with the BB84 protocol. For the single-photon source case, our result proves that the BB84 protocol strictly tolerates a higher quantum bit error rate than the three-state protocol; while for the coherent-source case, the BB84 protocol achieves a higher key generation rate and secure distance than the three-state protocol when a decoy-state method is used.Comment: 10 pages, 3 figures, 2 column

A staged approach with vincristine, adriamycin, and dexamethasone followed by bortezomib, thalidomide, and dexamethasone before autologous hematopoietic stem cell transplantation in the treatment of newly diagnosed multiple myeloma

Bortezomib-based regimens have significant activities in multiple myeloma (MM). In this study, we tested the efficacy of a total therapy with a staged approach where newly diagnosed MM patients received vincristine/adriamycin/dexamethsone (VAD). VAD-sensitive patients (≥75% paraprotein reduction) received autologous hematopoietic stem cell transplantation (auto-HSCT), whereas less VAD-sensitive patients (<75% paraprotein reduction) received bortezomib/thalidomide/dexamethasone (VTD) for further cytoreduction prior to auto-HSCT. On an intention-to-treat analysis, a progressive increase of complete remission (CR) rates was observed, with cumulative CR rates of 48% after HSCT. Seven patients progressed leading to three fatalities, of which two had central nervous system disease. The 3-year overall survival and event-free survival were 75.1% and 48.3%, respectively. Six patients developed oligoclonal reconstitution with new paraproteins. In the absence of anticoagulant prophylaxis, no patients developed deep vein thrombosis. The staged application of VAD+/–VTD/auto-HSCT resulted in an appreciable response rate and promising survivals. Our approach reduced the use of bortezomib without compromising the ultimate CR rate and is of financial significance for less affluent communities

Evaluation of an Internet–Short Message Service–Based Intervention for Promoting Physical Activity in Hong Kong Chinese Adolescent School Children: A Pilot Study

Evaluation of acceptability and preliminary efficacy of an Internet and short message service (SMS) intervention for promoting physical activity (PA) in Hong Kong Chinese school children. An 8-week quasi-experimental study non-randomly assigned 78 school children (mean age=12.8 years) to (a) an intervention group that received a stage-matched, Internet PA program two times a week and tailored SMS messages daily; or (b) a no-treatment control. Data were collected from September 2008 until June 2009. Acceptability measures included exposure rate and participant\u27s satisfaction. Efficacy measures were changes in stage of motivational readiness (SMR) and self-reported PA level. Intervention participants demonstrated significant pre-post increments in SMR (Z=−2.558, p=0.011) and self-reported PA level [F(1, 76)=4.50, p=0.04]. There was a non-significant trend between groups in both SMR (p=0.24) and PA (p=0.13). Despite the similar ratings of satisfaction between Internet (M=3.12±0.74) and SMS (M=3.12±0.84), participants displayed distinct patterns of exposure with 66% exhibiting a weekly login rate of 0.5 times/person and an average of 3.75 minutes/visit/person. In contrast, 79% of participants read an average of 1.3 SMS/person/week and 47% voluntarily replied to 3.8 SMS/person. These findings demonstrate the acceptability and preliminary efficacy of an Internet-SMS-based intervention for promoting PA in Hong Kong school children. The divergent exposure rates between the Internet and SMS may be a unique pattern for adolescents in early SMR. Future research should be cognizant of the importance of SMR since it may influence utilization and/or adherence