There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events-space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.

Purpose The dosimetric effect of edema on prostate implants have long been realized, but large uncertainties still exist in the estimation of dose actually received by the prostate. This study attempted to develop a new method to accurately estimate dose delivered to the prostate accounting for the variation of prostate volume and seed distribution, edema half‐lives, and times for postimplant evaluation. Methods and materials A series of prostate seed implants for Cs‐131, Pd‐103, and I‐125 with various prostate volumes were simulated in a water phantom using the TG‐43 algorithm on the Varian Eclipse treatment planning system. Dose analysis was performed to derive a quantitative relationship between the prostate peripheral dose and the prostate radius with the variation of prostate volume and seed distribution. Using this relationship to calculate dynamically, the total dose accumulated in the prostate (DT) accounting for the variation of prostate volume and seed distribution and edema half‐lives. Moreover, the total dose can be estimated statically based on the prostate volume that can be determined in a computerized tomography (CT) image taken at a time after implantation. The statically estimated total dose (DCT) was compared with DT to determine optimal imaging times as well as dose correction factors for other imaging times. Results An inverse power law was established between the prostate peripheral dose and prostate radius. The value of the power was 1.3 for Cs‐131 and I‐125, and 1.5 for Pd‐103, respectively. DT was derived dynamically using the inverse power law. Given the edema half‐lives, TE, of 4, 9.3, and 25 days and the volume expansion of 1.1 and 2.0 times of the prostate without edema, the optimal times for postimplant imaging were: 7, 9, and 16 days for TE = 4 days; 10, 14, and 28 days for TE = 9.3 days; and 12, 19, 45 days TE = 25 days, for Cs‐131, Pd‐103, and I‐125, respectively. DCT calculated using the prostate volume determined on the optimal days agreed with DT to 0.0%–1.8% and within 0.3% for most cases. For various prostate volumes, edema half‐lives, and nonoptimal times, DCT was able to achieve a 1% accuracy. Conclusion The postimplant dose calculation based on the proposed inverse power law for prostate seed implants with edema has improved the accuracy of postimplant dosimetry with accurate and patient‐specific dose corrections accounting for prostate size, edema half‐life, and postimplant imaging times. Optimal times for postimplant imaging have been accurately determined, and the high accuracy of postimplant dose calculation can be achieved for both optimal imaging times and nonoptimal imaging times.

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