We present the first results from a high-precision radial velocity study of the K2 III giant star α Ari. Observations were acquired over 6 nights in 2004 using the new high-resolution spectrograph BOES (Bohyunsan Observatory Echelle Spectrograph) of the 1.8-m telescope. A high radial-velocity precision was achieved by using the high-resolution (R = 90 000) mode of BOES and an iodine gas absorption cell. The radial velocity measurements made during JD = 2 452 948−2 452 950 show coherent, low-amplitude variations with a period of P 1 = 0.571 days (or aliases at 0.445 or 0.821 days), and an amplitude of 18.9 m s −1 . Observations of τ Cet over this same interval are constant to within 3 m s −1 . After subtracting the contribution of the 0.57-day period, we find evidence for a second period, P 2 = 0.190 days. Observations made on a second run during JD = 2 452 975−2 452 981 show that the radial velocity variations are indeed present, but on shorter time-scales and with a lower amplitude. Two probable periods fit the radial velocity measurements from the second run reasonably well: 0.185 days or an alias of 0.256 days. The shorter period coincides with the secondary one found in the earlier measurements. We conclude that, similar to other K-giant pulsating stars, α Ari shows unstable acoustic pulsations or mode switching on time scales of tens of days. The calculated pulsation constants for the dominant 0.571-day period is consistent with third-overtone pulsations, while the secondary periodicity found in both data runs corresponds to a high overtone (n ≥ 12).
A matched case-control study was used to determine pathogens and risk factors associated with gastroenteritis in a Taipei Emergency Department. Viruses (40.0%) were the leading cause of gastroenteritis, with noroviruses the most prevalent (33.2%). Bacteria were found in 26.0% of all cases, mostly suspected diarrheagenic E. coli (22.2%), followed by Salmonella spp. (5.4%) and Vibrio parahaemolyticus (4.2%). Giardia lamblia was identified in 16.4% of all cases. Statistical significance was noted for seven risk factors: taking antacids before gastroenteritis (OR = 3.91; 95% CI, 2.13, 7.15), other household members with gastroenteritis (OR = 5.18; 95% CI, 2.09, 12.85), attending a banquet (OR = 1.93; 95% CI, 1.25, 2.98), eating out (OR = 2.35; 95% CI, 1.30, 4.23), drinking bottled water (OR = 1.72; 95% CI, 1.07, 2.75), eating honey peaches (OR = 3.26; 95% CI, 1.24, 8.58), and eating raw oysters (OR = 3.24; 95% CI, 1.02, 10.28). Eating out was identified as the highest risk behavior, as measured by population attributable risk fraction (PAR) (50.9%). Respective PAR values for drinking bottled water, attending a banquet and taking antacids before illness were 19.7%, 19.6% and 17.6%. Of these, additional research on bottled water appears to be the highest priority, because this is the first time it has been identified as a risk factor for gastroenteritis.
We analyzed data accumulated during 2005 and 2006 by the Taiwan-American Occultation Survey (TAOS) in order to detect short-period variable stars (periods of < ∼ 1 hour) such as δ Scuti. TAOS is designed for the detection of stellar occultation by small-size Kuiper Belt Objects (KBOs) and is operating four 50cm telescopes at an effective cadence of 5Hz. The four telescopes simultaneously monitor the same patch of the sky in order to reduce false positives. To detect short-period variables, we used the Fast Fourier Transform algorithm (FFT) inasmuch as the data points in TAOS light-curves are evenly spaced. Using FFT, we found 41 short-period variables with amplitudes smaller than a few hundredths of a magnitude and periods of about an hour, which suggest that they are low-amplitude δ Scuti stars (LADS). The light-curves of TAOS δ Scuti stars are accessible online at the Time Series Center website (http://timemachine.iic.harvard.edu). a Combination of TAOS field ID and TAOS star ID. b We doubled amplitudes derived by PERIOD04. c SNR of frequencies derived using PERIOD04. dThe number of identifications / the number of zipper runs. Note that we did not count zipper runs observed by only one telescope. e The B8 star found to be an A5 star as explained in the text.f The G5 star found to be an F0 star as explained in the text.
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