Spinor Dynamics in an Antiferromagnetic Spin-1 Condensate

We observe coherent spin oscillations in an antiferromagnetic spin-1 Bose-Einstein condensate of sodium. The variation of the spin oscillations with magnetic field shows a clear signature of nonlinearity, in agreement with theory, which also predicts anharmonic oscillations near a critical magnetic field. Measurements of the magnetic phase diagram agree with predictions made in the approximation of a single spatial mode. The oscillation period yields the best measurement to date of the sodium spin-dependent interaction coefficient, determining that the difference between the sodium spin-dependent s-wave scattering lengths $a_{f=2}-a_{f=0}$ is $2.47\pm0.27$ Bohr radii.Comment: 5 pages, 2 figures. Changes: added reference, minor correction

Light forces in ultracold photoassociation

We study the time-resolved photoassociation of ultracold sodium in an optical dipole trap. The photoassociation laser excites pairs of atoms to molecular states of large total angular momentum at high intensities (above 20 kW/cm$^{2}$). Such transitions are generally suppressed at ultracold temperatures by the centrifugal barriers for high partial waves. Time-resolved ionization measurements reveal that the atoms are accelerated by the dipole potential of the photoassociation beam. We change the collision energy by varying the potential depth, and observe a strong variation of the photoassociation rate. These results demonstrate the important role of light forces in cw photoassociation at high intensities.Comment: 7 pages, 3 figure

Injury experience in Tanzania - Need for intervention

Objective: To determine distribution of injuries and factors associated with mortality in six hospitals of Tanzania mainland.Design: A Cross - Sectional hospital based study.Setting: Data were collected from casualty departments of Muhimbili Orthopaedic Institute, Morogoro, Mtwara, Kigoma, Musoma regional hospitals and Korogwe district hospital.Subjects: Patients who sustained injuries and attended in six involved hospitals between November 2011 and December 2012.Results: Of the 9316 injury patients seen, 71.7% were males. Majority (55%) were between 18 – 45 years age group. Traffic crashes were the leading cause of injuries and accounted for 47.5% of all injuries. Fractures accounted for 49.2%, and injuries were severe in 1.2% as determined by the Kampala trauma score II (KTS II). Majorities 66.7% were admitted and 2.4% died at the casualty. Factors associated with mortality were; being unemployed (P = 0.000), using ambulances to the hospital (P = 0.000), receiving medical attention within 2 to 10 hours after injury (P = 0.001), road traffic crashes (P = 0.000), 18 - 45 years age group (P = 0.003), low KTS II score (P = 0.000) and sustaining head injury (P = 0.000).Conclusion: Injuries in Tanzania are an important public health problem, predominantly in adult males, mostly due to traffic crashes. It is therefore important to reinforce preventive measures and pre-hospital emergency service is urgently needed

Ultraslow propagation of matched pulses by four-wave mixing in an atomic vapor

We have observed the ultraslow propagation of matched pulses in nondegenerate four-wave mixing in a hot atomic vapor. Probe pulses as short as 70 ns can be delayed by a tunable time of up to 40 ns with little broadening or distortion. During the propagation, a probe pulse is amplified and generates a conjugate pulse which is faster and separates from the probe pulse before getting locked to it at a fixed delay. The precise timing of this process allows us to determine the key coefficients of the susceptibility tensor. The presence of gain in this system makes this system very interesting in the context of all-optical information processing.Comment: 5 pages, 4 figure

Narrow-line magneto-optical cooling and trapping of strongly magnetic atoms

Laser cooling on weak transitions is a useful technique for reaching ultracold temperatures in atoms with multiple valence electrons. However, for strongly magnetic atoms a conventional narrow-line magneto-optical trap (MOT) is destabilized by competition between optical and magnetic forces. We overcome this difficulty in Er by developing an unusual narrow-line MOT that balances optical and magnetic forces using laser light tuned to the blue side of a narrow (8 kHz) transition. The trap population is spin-polarized with temperatures reaching below 2 microkelvin. Our results constitute an alternative method for laser cooling on weak transitions, applicable to rare-earth-metal and metastable alkaline earth elements.Comment: To appear in Phys. Rev. Lett. 4 pages, 5 figure

Comparison and accuracy assessment of wetland land cover classification systems in the Willamette Valley, Oregon

The purpose of this study was to better understand the level of wetland classification consistency among three different land cover layers created using Geographical Information System (GIS) and remote sensor technology. Where inconsistencies in data existed, the goal was to identify the kinds of inconsistencies that occur. The results were focused on wetland land cover classes used for habitat identification and suitability studies. A GIS was used to help manage and combine the data from the three different systems spatially. The different land cover classification systems used were: 1) the Oregon Department of Fish and Wildlife Classification System (ODFW), 2) the National Wetlands Inventory (NWI) and 3) the Pacific Northwest Ecosystem Consortium's Classification (ERC/ARA). Digital orthophotos and site visits were used to verify the accuracy of a stratified random sample of the areas identified as wetlands by each system. From this verification process inferences about the relative accuracy of each system of classification were made. Data on the 1) total area and frequency of wetland polygons; 2) types of wetlands; 3) spatial agreement; 4) uniquely identified wetlands, and 5) strengths and weaknesses (comparison between verification system classifications and stratified random sample with field verified data) were analyzed and compared for the three land covers

Growth, Nitrogen and Phosphorus Economy in Two \u3ci\u3eLotus Glaber\u3c/i\u3e Mill. Cytotypes Grown Under Contrasting P-Availability

Lotus glaber Mill. (lotus) is a forage legume with its origin in Europe which has shown an excellent adaptation to the Depressed Pampas of the Province of Buenos Aires, Argentina. The soils colonized by lotus usually have poor drainage, moderate sodium and low extractable P concentrations. An experiment was performed with the aim of comparing the early growth and economy of phosphorus (P) and nitrogen (N) within two L. glaber cytotypes differing in their ploidy level, a commercial diploid versus an induced autotetraploid population (Barufaldi et al., 2001)