A new inductively coupled plasma atomic emission spectrometry (ICP‐AES) method is presented for rapid and routine analysis of Sr/Ca molar ratios in seawater, with a long‐term precision of < 0.2%. It is an adaptation of a method widely employed for the analysis of coral aragonite Sr/Ca ratios in marine paleothermometry studies, which are based on the assumption that the seawater Sr/Ca ratio is constant in space and time. While prior studies have shown variations of up to 1% with depth, smaller variations at the ocean surface are generally accounted for via empirical, species‐specific calibrations of coral Sr/Ca vs. temperature. We found Sr/Ca variations in some coastal waters to be even larger, with distinct periodicity, complicating this approach. Although the high precision necessary for measurements of seawater Sr/Ca has previously relied on advanced mass spectrometry, long analysis times, and expensive isotopic spikes, our method uses more accessible instrumentation and is both time‐ and cost‐saving. The intricate composition of seawater, relative to coral aragonite solutions, requires an intensity ratio calibration technique combined with rigorous normalization to a suitable seawater standard. Key aspects of our method are discussed, including the choice of wavelengths, instrument parameters, accuracy, precision, and matrix effects. Special attention is given to the need for a certified seawater Sr/Ca reference standard, which does not presently exist. Analytical validation is provided by concurrent sharp gradients in Sr/Ca and δ18O, coinciding with the Florida landfall of hurricane Irma, as recorded at near‐daily resolution in a continuous seawater sample collected with an osmotic pump.

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Few studies evaluate the use of handheld ultrasound devices for point-of-care ultrasonography in the emergency department. We hypothesized that image acquisition time and image quality are similar between a handheld device and a traditional device. We compared these 2 types of devices in healthy, non-pregnant adults with using a crossover non-inferiority design while acquiring Rapid Ultrasound for Shock and Hypotension (RUSH) view. We excluded those with a history of surgical intervention or known abnormality to the lungs, abdomen, or pelvis. Images were compiled into a de-identified video clip reviewed for image quality by 2 blinded reviewers. Cohen's Kappa was used to determine interrater agreement. Disagreements were adjudicated by an independent physician. Imaging time was compared using a paired Student's t test. Of 59 screened participants, 9 were excluded. Most subjects (N = 30, 60%) were female with a mean age of 39 (Range: 19-67) years. The median time to complete the RUSH exam did not differ (handheld 249.4, interquartile range 33.5 seconds); traditional 251.4, interquartile range 66.3 seconds); [P = 0.81]). Agreement between ultrasound reviewers was good (agreement 83%; k = 0.69; 95% CI, 0.49-0.88). Images were determined to be of adequate quality for interpretation in 41/50 (82%) and 43/50 (86%) in the handheld and traditional devices, respectively (P = 0.786). Neither time to image acquisition nor image quality differed between the handheld and traditional devices. The handheld device may be an alternative for use in RUSH exams.

Coral paleothermometry based on the analysis of Sr/Ca ratios in the skeletal aragonite (CaCO 3 ) of scleractinian species is one of the most well-established and widely applied geochemical methods in climate studies of the recent past (e.g.,

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