We summarize antimicrobial resistance surveillance data in human and chicken isolates of Campylobacter . Isolates were from a sentinel county study from 1989 through 1990 and from nine state health departments participating in National Antimicrobial Resistance Monitoring System for enteric bacteria (NARMS) from 1997 through 2001. None of the 297 C. jejuni or C. coli isolates tested from 1989 through 1990 was ciprofloxacin-resistant. From 1997 through 2001, a total of 1,553 human Campylobacter isolates were characterized: 1,471 (95%) were C. jejuni , 63 (4%) were C. coli , and 19 (1%) were other Campylobacter species. The prevalence of ciprofloxacin-resistant Campylobacter was 13% (28 of 217) in 1997 and 19% (75 of 384) in 2001; erythromycin resistance was 2% (4 of 217) in 1997 and 2% (8 of 384) in 2001. Ciprofloxacin-resistant Campylobacter was isolated from 10% of 180 chicken products purchased from grocery stores in three states in 1999. Ciprofloxacin resistance has emerged among Campylobacter since 1990 and has increased in prevalence since 1997.

We describe the Navy Prototype Optical Interferometer (NPOI), a joint project of the Naval Research Laboratory (NRL) and the US Naval Observatory (USNO) in cooperation with Lowell Observatory. The NPOI has recently begun operations at the Lowell Observatory site near Flagsta †, Arizona, obtaining its Ðrst images, of a binary star, in 1996 May and June and its Ðrst limb-darkening observations during 1996 November to 1997 February. This paper gives an overview of the NPOI, including the characteristics of optical interferometry that a †ect its design.The NPOI includes subarrays for imaging and for astrometry. The imaging subarray consists of six moveable 50 cm siderostats feeding 12 cm apertures, with baseline lengths from 2.0 to 437 m. The astrometric subarray consists of four Ðxed 50 cm siderostats feeding 12 cm apertures (35 cm apertures to be installed in 1998), with baseline lengths from 19 m to 38 m. The shared back end covers 450È850 nm in 32 channels. The NPOI features vacuum feed and delay systems, active group-delay fringe tracking, and a high degree of automation. The astrometric subarray also includes an extensive site laser metrology system to measure the motions of the siderostats with respect to one another and to the bedrock.For imaging stellar surfaces, arrays with equal spacing between elements are superior to arrays that have been laid out to optimize (u, v) coverage and that therefore have unequal spacing. The imaging subarray of the NPOI provides a number of equally spaced conÐgurations with linear scales at ratios of B1.64. Unequally spaced conÐgurations are available for a variety of other imaging programs. Coherence across either type of imaging conÐguration is maintained by "" phase bootstrapping ÏÏ : the phases on the longest baselines, on which fringes may be too weak to track, are stabilized by tracking fringes on the shortest baselines.In principle, the four elements of the astrometric subarray provide enough independent baselines to solve for stellar positions and the array geometry simultaneously while observing each of 11 stars only once.The anticipated magnitude limit is 7 mag or better with 12 cm apertures and average seeing ; with 35 cm apertures, we expect the limit to be one or more magnitudes fainter. The anticipated wide-angle astrometric precision of the NPOI is B2 mas. The best angular resolution of the imaging subarray will be B200 kas. Our experience with the Mark III interferometer suggests that we will be able to measure stellar diameters as small as 200 kas with 1% precision and binary star separations as small as o B 65 kas (for *m B 0 mag) or o B 200 kas (for *m B 3È4 mag). With its large bandwidth and phase bootstrapping, the imaging subarray should be able to make images resolution elements across the disks Z10 of nearby late-type stars.

We present new interferometric observations for 74 luminous red stars, made in the near-infrared. We show that our 2.2 km uniform-disk diameters agree with other near-infrared diameter determinations (lunar occultations and interferometers) for 22 stars measured in common with ours. From our new data, we derive e †ective temperatures that are compared with our previous work and with comparable observations made by lunar occultations at Kitt Peak. The combined data set yields 91 luminosity class II, IIÈIII, and III stars that have well-determined spectral types spanning the range from about K0 to about M8. There are 83 stars in the sample that deÐne an approximately linear relationship between spectral type and e †ective temperature for giants, with a dispersion of 192 K at each spectral type. Eight of the stars have temperatures that are roughly 750 K too low for their spectral types. These stars are not known to be at the high-luminosity end of the range of stars observed and are not recognized as binary stars. At present, we have no explanation for their low e †ective temperatures. We also show that Hipparcos parallaxes, combined with our angular diameters, yield linear radii precise enough to see di †erences in the average radius between luminosity class II and luminosity class III stars.

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