Eight years of Ca II surface activity records from Mount Wilson Observatory measured for 12 bright G-K III stars have been analyzed in order to detect periodic variations attributable to rotation. We also present photometric V-band data for these stars from the Fairborn 0.25-m Automated Photometric Telescope (APT) that yielded a photometric period in one case and rms deviations from apparently constant brightness levels for the remaining 11 stars. The Ca II data yielded rotation periods for 10 out of 12 giant stars. We demonstrate that the photometric variability and nonvariability of these stars can be predicted from their Rossby numbers calculated from our observed rotation periods and convective turnover times scaled up from the main sequence.

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The relationships between serum levels of trace elements and breast cancer remain relatively unknown. In this study, we investigate serum levels of seven trace elements in Korean breast cancer patients compared to controls without breast cancer. Serum trace element levels were determined using inductively coupled plasma mass spectrometry in Korean breast cancer patients before initiation of breast cancer treatment. Korean females without breast cancer served as a control group. Trace element levels were measured in the discovery cohort (n = 287) and were validated in an independent cohort (n = 142). We further investigated possible associations between trace element levels and the presence of lymph node metastasis, distant metastasis, or triple-negative breast cancer among breast cancer patients in subgroup analyses. Serum manganese and molybdenum levels were significantly higher (p < 0.05) in breast cancer patients than in controls. Serum copper levels were significantly higher in breast cancer patients with distant metastasis, while selenium levels were significantly lower. Other trace elements were neither significantly different between breast cancer patients and controls nor between subgroups of breast cancer patients. Our study provides insights about the potential roles and impacts of trace elements through an assessment of the associations between trace elements and breast cancer.