Optical and evaporative cooling of cesium atoms in the gravito-optical surface trap

We report on cooling of an atomic cesium gas closely above an evanescent-wave atom mirror. At high densitities, optical cooling based on inelastic reflections is found to be limited by a density-dependent excess temperature and trap loss due to ultracold collisions involving repulsive molecular states. Nevertheless, very good starting conditions for subsequent evaporative cooling are obtained. Our first evaporation experiments show a temperature reduction from 10muK down to 300nK along with a gain in phase-space density of almost two orders of magnitude.Comment: 8 pages, 6 figures, submitted to Journal of Modern Optics, special issue "Fundamentals of Quantum Optics V", edited by F. Ehlotzk

Cold atom gas at very high densities in an optical surface microtrap

An optical microtrap is realized on a dielectric surface by crossing a tightly focused laser beam with an horizontal evanescent-wave atom mirror. The nondissipative trap is loaded with $\sim$$10^5$ cesium atoms through elastic collisions from a cold reservoir provided by a large-volume optical surface trap. With an observed 300-fold local increase of the atomic number density approaching $10^{14}{\rm cm}^{-3}$, unprecedented conditions of cold atoms close to a surface are realized

Evanescent-wave trapping and evaporative cooling of an atomic gas near two-dimensionality

A dense gas of cesium atoms at the crossover to two-dimensionality is prepared in a highly anisotropic surface trap that is realized with two evanescent light waves. Temperatures as low as 100nK are reached with 20.000 atoms at a phase-space density close to 0.1. The lowest quantum state in the tightly confined direction is populated by more than 60%. The system offers intriguing prospects for future experiments on degenerate quantum gases in two dimensions

Preparation of Some lmino- and Cyano-imino-substituted Barbiturates

A number of imino- and cyano-iminobarbituric acid derivatives has been prepared in good yield by gradually adding sodium methoxide - as condensation catalyst - to some substituted cyanoacetic and malonic esters reacting with urea, dicyandiamide and guanidine

Marked changes in electron transport through the blue copper protein azurin in the solid state upon deuteration

Measuring electron transport (ETp) across proteins in the solid-state offers a way to study electron transfer (ET) mechanism(s) that minimizes solvation effects on the process. Solid state ETp is sensitive to any static (conformational) or dynamic (vibrational) changes in the protein. Our macroscopic measurement technique extends the use of ETp meas-urements down to low temperatures and the concomitant lower current densities, because the larger area still yields measurable currents. Thus, we reported previously a surprising lack of temperature-dependence for ETp via the blue copper protein azurin (Az), from 80K till denaturation, while ETp via apo-(Cu-free) Az was found to be temperature de-pendent \geq 200K. H/D substitution (deuteration) can provide a potentially powerful means to unravel factors that affect the ETp mechanism at a molecular level. Therefore, we measured and report here the kinetic deuterium isotope effect (KIE) on ETp through holo-Az as a function of temperature (30-340K). We find that deuteration has a striking effect in that it changes ETp from temperature independent to temperature dependent above 180K. This change is expressed in KIE values between 1.8 at 340K and 9.1 at \leq 180K. These values are particularly remarkable in light of the previously reported inverse KIE on the ET in Az in solution. The high values that we obtain for the KIE on the ETp process across the protein monolayer are consistent with a transport mechanism that involves through-(H-containing)-bonds of the {\beta}-sheet structure of Az, likely those of am-ide groups.Comment: 15 pages, 3 figures, 2 Supplementary figure

Proceedings of the 19th Annual Meeting, Southern Soybean Disease Workers (February 19-20, 1992, St. Louis, Missouri)

Contents Southern Soybean Disease Workers 1991-1992 officers 1991-1992 Program Committee Graduate student competition Interactions of Macrophomina phaseolina with two soybean cultivars under four irrigation regimes. SR Kendig and JC Rupe Influence of soybean planting dates on the incidence and severity of Sudden Death Syndrome. SS Alghamdi, PT Gibson, and MA Shenaut The interrelationship of Heterodera glycines and Fusarium solani in sudden death syndrome of soybean. KS McLean and GW Lawrence Frogeye leaf spot of soybean: evaluation of cultivars and isolates. PF Pace, DB Weaver, and LD Ploper Soybean cyst nematode race symposium SCN race scheme: a historical perspective. JA Fox Races of Heterodera glycines: a nematological perspective. TL Niblack Races of Heterodera glycines and level of resistance in soybean cultivars. SC Anand Differentiating soybean responses to soybean cyst nematode races. DP Schmitt and JG Shannon Strategies for improved soybean yields and profits in the Southern US. JH Palmer Contributed papers Evaluation of resistance to Rhizoctonia Foliar Blight of soybean. CS Kousik, GB Padgett, JP Snow, and BG Harville Five years of soybean variety testing for SDS response. PT Gibson, M Schmidt, MA Shenaut, and O Myers, Jr Effect of tillage, planting date, and cultivar on the severity of sudden death syndrome, Septoria brown spot and downy mildew of soybean. JA Wrather, TL Niblack, GS Smith, and SC Anand Effect sof soybean planting date on severity of stem canker. AY Chambers Comparative virulence of stem canker isolates from southern soybean growing areas. GL Sciumbato and BL Keeling Effects of a low rate of aldicarb on soybean canopy development and yield, weed and insect populations in Heterodera glycines-infested fields. SR Koenning, KR Barker, HD Coble, and JR Bradley Effect of soybean cyst nematode on soybean isolines differing for maturity. WJ Wiebold and TL Niblack Effect of repeated application of selected herbicides and nematicides/insecticides on soybean cyst nematode density. P Donald, A Keaster, R Kremer, and B Sims Southern United States soybean disease loss estimate for 1991. Southern Soybean Disease Workers, Soybean Disease Loss Estimate Committee. Compiled by GL Sciumbato and DL Turnage SSDW Treasurer\u27s report. GG Hammes Southern Soybean Disease Workers 1990-1991 committee chairmen Southern Soybean Disease Workers 1991 award recipients Proceedings of the Southern Soybean Disease Workers is published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by the author(s). The opinions expressed by the participants at this conference are their own and do not necessarily represent the views of the Southern Soybean Disease Workers. Mention of trademark or propriety product in this Proceedings does not constitute a guarantee, warranty, of endorsement of that product by the Southern Soybean Disease Workers

Rates of referable eye disease in the Scottish National Diabetic Retinopathy Screening Programme

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.Peer reviewedPublisher PD

Opto-mechanical measurement of micro-trap via nonlinear cavity enhanced Raman scattering spectrum

High-gain resonant nonlinear Raman scattering on trapped cold atoms within a high-fineness ring optical cavity is simply explained under a nonlinear opto-mechanical mechanism, and a proposal using it to detect frequency of micro-trap on atom chip is presented. The enhancement of scattering spectrum is due to a coherent Raman conversion between two different cavity modes mediated by collective vibrations of atoms through nonlinear opto-mechanical couplings. The physical conditions of this technique are roughly estimated on Rubidium atoms, and a simple quantum analysis as well as a multi-body semiclassical simulation on this nonlinear Raman process is conducted.Comment: 7 pages, 2 figure