In situ imaging of vortices in Bose-Einstein condensates

Laboratory observations of vortex dynamics in Bose-Einstein condensates (BECs) are essential for determination of many aspects of superfluid dynamics in these systems. We present a novel application of dark-field imaging that enables \texttt{\it in situ} detection of two-dimensional vortex distributions in single-component BECs, a step towards real-time measurements of complex two-dimensional vortex dynamics within a single BEC. By rotating a $^{87}$Rb BEC in a magnetic trap, we generate a triangular lattice of vortex cores in the BEC, with core diameters on the order of 400 nm and cores separated by approximately 9 $\mu$m. We have experimentally confirmed that the positions of the vortex cores can be determined without the need for ballistic expansion of the BEC.Comment: 5 pages, 4 figure

Achieving the Millennium Development Goals in Africa: Harnessing E-Learning Potentials

It is increasingly been accepted by various stakeholders that the realization of development targets in the developing countries depends more, among other measures, on knowledge. One of the centerpieces of international aid efforts in the new millennium has been the effort to achieve eight millennium developments goals (MDGs) for developing countries by the year 2015. Achieving the MDGs paradigm will require both knowledge and skills. e-learning is gaining popularity and bringing knowledge to our doorposts. Can it deliver in respect of achieving the 8 Millennium Development Goals?  This paper explores how e-learning is situated in the drive towards realization of MDGs in the African continent. Literature studies have been conducted to determine the potentials and possibilities inherent in e-learning as a tool for MDGs realization in Africa. The success of e-learning largely depends on access, affordability of technological resources and willingness of the people. Keywords: e-learning & Millennium Development Goals (MDGs

Generalized three-dimensional simulation of ferruled coupled-cavity traveling-wave-tube dispersion and impedance characteristics

The frequency-phase dispersion and Pierce on-axis interaction impedance of a ferruled, coupled-cavity, traveling-wave tube (TWT), slow-wave circuit were calculated using the three-dimensional simulation code Micro-SOS. The utilization of the code to reduce costly and time-consuming experimental cold tests is demonstrated by the accuracy achieved in calculating these parameters. A generalized input file was developed so that ferruled coupled-cavity TWT slow-wave circuits of arbitrary dimensions could be easily modeled. The practicality of the generalized input file was tested by applying it to the ferruled coupled-cavity slow-wave circuit of the Hughes Aircraft Company model 961HA TWT and by comparing the results with experimental results

HBV and HCV test uptake and correlates among men who have sex with men in China: a nationwide cross-sectional online survey.

OBJECTIVES: Hepatitis B virus (HBV) and hepatitis C virus (HCV) cause substantial morbidity and mortality in low-income and middle-income countries, including China. WHO guidelines recommend men who have sex with men (MSM) receive HBV and HCV screening. The purpose of this study was to determine the proportion of MSM in China who have HBV and HCV tested and identify correlates of test uptake. METHODS: We conducted an online cross-sectional survey of young MSM in China. Respondents were asked to report previous HBV and HCV testing, sociodemographic information, sexual risk factors for hepatitis infection, other STI testing and primary care physician (PCP) status. Associations were analysed by logistic regression. RESULTS: 503 eligible MSM completed the survey. 41.0% (206/503) of MSM had HCV tested, and 38.2% (60/157) of MSM with no or uncertain HBV vaccination had HBV tested. In multivariate analysis, HCV testing was correlated with HBV testing (adjusted OR (aOR) 22.98, 95% CI 12.11 to 43.60), HIV testing (aOR 3.64, 95% CI 1.92 to 6.91), HIV-positive status (aOR 1.78, 95% CI 1.07 to 2.98) and having a PCP (aOR 2.40, 95% CI 1.44 to 3.98). Among MSM with no or uncertain HBV vaccination, HBV testing was correlated with HCV testing (aOR 80.85, 95% CI 20.80 to 314.33), HIV testing (aOR 5.26, 95% CI 1.81 to 15.28), HIV-positive status (aOR 3.00, 95% CI 1.22 to 7.37) and having a PCP (aOR 2.69, 95% CI 1.00 to 7.26). CONCLUSIONS: Our data suggest many young MSM in China have not received hepatitis testing. HCV testing rates were lower than those recently reported among MSM in Australia and the USA. The strong correlation between HBV and HCV testing suggests bundled testing interventions may be useful for MSM in China. Men with a PCP were more likely to have received hepatitis testing, consistent with literature demonstrating the importance of primary care in expanding access to testing

Radiometer offsets and count conversion coefficients for the Earth Radiation Budget Experiment (ERBE) spacecraft for the years 1984, 1985, and 1986

A compendium is presented of the ground and inflight scanner and nonscanner offsets and count conversion (gain) coefficients used for the Earth Radiation Budget Experiment (ERBE) production processing of data from the ERBS, NOAA-9, and NOAA-10 satellites for the 1 Nov. 1984 to 31 Dec. 1986

ACUTE EFFECTS OF STRENGTH TRAINING ON RUNNING ECONOMY

Sequencing strength training before aerobic conditioning is practised without empirical support. This study explored the acute effects of strength training on running economy and 3-D kinematics in five males. Running was performed on a treadmill at 12 and 14 km/h on three separate occasions. Trial 1 and 2 involved no strength training with data used to assess response stability of the variables. Before Trial 3, three sets of three repetitions at 85% of 1 repetition maximum of squat, bench press and deadlift with 3-5 minutes of rest were performed. Compared to Trial 2 no significant differences were observed when strength training was performed. Only a tendency of increased knee flexion (4.5°) at foot strike at the higher running velocity was observed. This suggests that running kinematics were changed exposing participants to long-term chronic injuries

Interferometric Observations of the Nuclear Region of Arp220 at Submillimeter Wavelengths

We report the first submillimeter interferometric observations of an ultraluminous infrared galaxy. We observed Arp220 in the CO J=3-2 line and 342GHz continuum with the single baseline CSO-JCMT interferometer consisting of the Caltech Submillimeter Observatory (CSO) and the James Clerk Maxwell Telescope (JCMT). Models were fit to the measured visibilities to constrain the structure of the source. The morphologies of the CO J=3-2 line and 342GHz continuum emission are similar to those seen in published maps at 230 and 110GHz. We clearly detect a binary source separated by about 1 arcsec in the east-west direction in the 342GHz continuum. The CO J=3-2 visibility amplitudes, however, indicate a more complicated structure, with evidence for a compact binary at some velocities and rather more extended structure at others. Less than 30% of the total CO J=3-2 emission is detected by the interferometer, which implies the presence of significant quantities of extended gas. We also obtained single-dish CO J=2-1, CO J=3-2 and HCN J=4-3 spectra. The HCN J=4-3 spectrum, unlike the CO spectra, is dominated by a single redshifted peak. The HCN J=4-3/CO J=3-2, HCN J=4-3/HCN J=1-0 and CO J=3-2/2-1 line ratios are larger in the redshifted (eastern) source, which suggests that the two sources may have different physical conditions. This result might be explained by the presence of an intense starburst that has begun to deplete or disperse the densest gas in the western source, while the eastern source harbors undispersed high density gas.Comment: 17 pages, 9 figures, 4 Tables. accepted by Ap

Seerratus Anterior Plane Block (SAPB) Improves Paine Control in Rib Fractures

Background: •Trauma is a major cause of morbidity and mortality worldwide. Rib fractures are identified in at least 10% of all injured patients. •Rib fractures can lead to significant respiratory complications, with pneumonia and respiratory failure occurring in up to 31% of patients with rib fractures. Early initiation of aggressive pain control and pulmonary hygiene with incentive spirometry are standard of care to prevent complications from developing. •In the Emergency Department, patients with rib fractures typically receive systemic analgesia that is largely narcotic-based. This pain control strategy puts patients at risk for the side effects of narcotics such as constipation, delirium, and opioid addiction. •Regional ultrasound-guided anesthesia is well within the purview of emergency physicians and offers a safe and effective alternative to systemic pain medications. A regional block known as the Serratus Anterior Plane Block (SAPB) was described in the anesthesia literature in 2013 as a strategy for improving pain related to rib fractures. •The literature evaluating the effectiveness of the SAPB is limited to case reports with a small number of patients (n = 1-6). No published studies have assessed incentive spirometry performance in patients who have received the SAPB, described the systemic analgesia required by patients who have received the SAPB, or formally evaluated the safety of the SAPB

Articulatory Tradeoffs Reduce Acoustic Variability During American English /r/ Production

Acoustic and articulatory recordings reveal that speakers utilize systematic articulatory tradeoffs to maintain acoustic stability when producing the phoneme /r/. Distinct articulator configurations used to produce /r/ in various phonetic contexts show systematic tradeoffs between the cross-sectional areas of different vocal tract sections. Analysis of acoustic and articulatory variabilities reveals that these tradeoffs act to reduce acoustic variability, thus allowing large contextual variations in vocal tract shape; these contextual variations in turn apparently reduce the amount of articulatory movement required. These findings contrast with the widely held view that speaking involves a canonical vocal tract shape target for each phoneme.National Institute on Deafness and Other Communication Disorders (1R29-DC02852-02, 5R01-DC01925-04, 1R03-C2576-0l); National Science Foundation (IRI-9310518