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1. Self-reported and biometrically measured hot flashes in relation to ambient temperature and humidity.

   Sievert, Lynnette L; Shreyer, Sofiya S; Brown, Daniel E. (December 2022, Menopause)

   Self-reported and biometrically measured hot flashes in relation to ambient temperature and humidity Lynnette L. Sievert, PhD1, Sofiya Shreyer, MA,1 Daniel E. Brown, PhD2 1Anthropology, UMass Amherst, MA; 2Anthropology, University of Hawaii at Hilo, HI Objective: Warm ambient temperatures provoke hot flashes in the laboratory, but outside the laboratory the temperature to hot flash relationship is less consistent. A study in Bangladesh and London found that temperature and humidity at 12:00 and 18:00 were not associated with self-reported or biometrically measured hot flashes. However, in Spain and three South American countries, higher temperatures and humidities were associated with more frequent and problematic hot flashes. The study reported here differs from previous work in that we asked women to carry an ambulatory temperature and humidity monitor while wearing an ambulatory hot flash monitor. The purpose of this study was to examine the relationship between concurrent temperature, humidity, and hot flash experience. We hypothesized more frequent hot flashes with higher ambient temperatures. Design: Women aged 45 to 55 years were drawn from western Massachusetts for an ongoing cross-sectional study (n=195) from October through April (2019-2023). Exclusion criteria included use of medications that dampen hot flashes. Hot flashes were queried with a semi-structured questionnaire: During the past two weeks, have you been bothered by hot flashes (not at all, a little, somewhat, a lot)? Currently, how often do they occur (from less than 1/month to 5+ times/day, scored 0-8)? Hot flashes were also assessed by sternal skin conductance using a Biolog ambulatory hot flash monitor (3991x/1-SCL, UFI, Morro Bay, CA). Subjective hot flashes during the 24-hour study period were recorded with buttons on the hot flash monitor. Ambient temperature and humidity were continuously recorded with the GSP-6 Temperature and Humidity Data Logger Recorder (Elitech Technology, San Jose, CA). Menopausal status was categorized as pre-, peri- (change in cycle length >6 days) and post- (absence of menses for 12 months). Univariate relationships between temperature (maximum, minimum, mean), humidity (maximum, minimum, mean), and hot flashes (yes/no) were examined by t-tests. Temperature, humidity, and hot flash bothersomeness were examined by ANOVA. Pearson correlations were used to evaluate temperature, humidity, and hot flash frequencies (from the questionnaire and Biolog monitor). Logistic regression was also applied to examine temperature and humidity measures in relation to hot flashes while adjusting for menopausal status. Results: Mean ambient temperatures ranged from 16.3 to 30.1oC (mean 24.5oC, s.d. 2.8); mean humidities ranged from 18.9 to 68.6% (mean 40.8%, s.d. 9.2). Minimum temperature was positively associated with minimum (r=0.508, p<0.001) and mean (r=0.316, p<0.001) measures of humidity. Hot flash bothersomeness was described as not at all (31%), a little (23%), somewhat (23%), and a lot (24%). In univariate analyses, maximum, minimum, and mean temperatures and humidity levels were not associated with hot flashes (yes/no) or with the bothersomeness of hot flashes. Temperature measures were not correlated with current frequency of hot flashes or with the frequency of objective or subjective hot flashes during the study period. However, the current frequency of hot flashes was negatively correlated with minimum (r=-0.205, p<0.01) and mean (r=-0.196, p<0.01) levels of humidity, so that as humidity levels increased, the likelihood of hot flashes decreased. Although participants were keen to wear the monitor for 24-hours, the Biolog monitor quit during 38% of the studies. In the majority of cases, participants restarted the monitor. Compared to monitors that continued to function, monitors that quit were more likely to be worn when minimum temperatures were lower (mean 6.8oC vs. 8.9 oC, p=0.03), minimum humidity levels were lower (mean 17.2% vs. 22.6%, p<0.001), and mean humidity levels were lower (mean 37.2% vs. 43.0%, p<0.001). Conclusion: The hypothesized positive relationship between temperature and hot flashes was not supported. Instead, as humidity levels increased, the likelihood of hot flashes decreased. This preliminary study will be followed by syncing of the temperature, humidity, and hot flash data in order to study how changes in temperature and/or humidity may provoke hot flashes. Funding: NSF Grant #BCS-1848330 

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2. Estimating brown adipose tissue activity for a study of hot flashes [Abstract]

   https://doi.org/10.1002/ajhb.23593  

   Sievert, Lynnette Leidy; Shreyer, Sofiya I; Brown, Daniel E (March 2021, American Journal of Human Biology)

   null (Ed.)

   This presentation compares methods of estimating brown adipose tissue (BAT). As part of an ongoing study of BAT activity in relation to hot flashes, we asked women aged 45-55 to place their hand in cool (17oC) water. We took a thermal image of each woman (Flir camera) before and after the cooling of her hand. To estimate BAT activity, we compared the change in temperature in the supraclavicular area with a control area. Initially, we used a point on the mid-sternum as the control. Because we were concerned that there may be BAT tissue along the sternum, we also tried a control region on the mid-right arm. We used two equations to estimate BAT activity. The first computed the difference in maximum supraclavicular temperature (SCT) minus the difference in the control temperature [(PostMaxSupraclavicular – PreMaxSupraclavicular) - (PostControlMean - PreControlMean)]. Mean BAT estimated from the maximum SCT and arm temperature was higher (0.80, s.d. 0.51, range 0 to 2.10) than from the maximum SCT and sternal temperature (0.63, s.d. 0.45, range 0 to 1.70). There was no relationship between biceps skinfold and arm temperature, or between other anthropometric measures (summed skinfolds, BMI, percent body fat) and estimates of BAT. The sample size is, to date, too small to draw conclusions (n=36), but as the reported severity of hot flashes increased (“none,” “a little,” “somewhat,” “a lot”) the mean BAT estimated with the sternal control also increased (0.49, 0.65, 0.68, 0.74). This was not true when the arm was used as the control. Support: NSF #BCS-1848330 

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3. Electrically Active Tropical Cyclone Diurnal Pulses in the Atlantic Basin

   https://doi.org/10.1175/MWR-D-19-0129.1  

   Ditchek, Sarah D.; Corbosiero, Kristen L.; Fovell, Robert G.; Molinari, John (October 2019, Monthly Weather Review)

   While the frequency and structure of Atlantic basin tropical cyclone diurnal cooling and warming pulses have recently been explored, how often diurnal pulses are associated with deep convection was left unanswered. Here, storm-relative, GridSat-B1, 6-h IR brightness temperature difference fields were supplemented with World Wide Lightning Location Network (WWLLN) data to answer that question. Electrically active, long-lived cooling and warming pulses were defined objectively by determining critical thresholds for the lightning flash density, areal coverage, and longevity within each pulse. Pulses with lightning occurred 61% of the time, with persistently electrically active pulses (≥9 h, ACT) occurring on 38% of pulse days and quasi–electrically active pulses (3–6 h, QUASI) occurring on 23% of pulse days. Electrically inactive pulses (<3 h, INACT) occurred 39% of the time. ACT pulse days had more pulses located right-of-shear, the preferred quadrant for outer-rainband lightning activity, and were associated with more favorable environmental conditions than INACT pulse days. Cooling pulses were more likely to occur in lower-shear environments while warming pulses were more likely to occur in high-shear environments. Finally, while the propagation speeds of ACT and INACT cooling pulses and ACT warming pulses did lend support to the recent gravity wave and tropical squall-line explanations of diurnal pulses, the INACT warming pulses did not and should be studied further. 

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4. A new instability domain of CNO-flashing low-mass He-core stars on their early white-dwarf cooling branches

   https://doi.org/10.1051/0004-6361/202039831  

   Calcaferro, Leila M.; Córsico, Alejandro H.; Althaus, Leandro G.; Bell, Keaton J. (March 2021, Astronomy & Astrophysics)

   null (Ed.)

   Context. Before reaching their quiescent terminal white-dwarf cooling branch, some low-mass helium-core white dwarf stellar models experience a number of nuclear flashes which greatly reduce their hydrogen envelopes. Just before the occurrence of each flash, stable hydrogen burning may be able to drive global pulsations that could be relevant in shedding some light on the internal structure of these stars through asteroseismology, similarly to what occurs with other classes of pulsating white dwarfs. Aims. We present a pulsational stability analysis applied to low-mass helium-core stars on their early white-dwarf cooling branches going through CNO flashes in order to study the possibility that the ε mechanism is able to excite gravity-mode pulsations. We assess the ranges of unstable periods and the corresponding instability domain in the log g  −  T eff plane. Methods. We carried out a nonadiabatic pulsation analysis for low-mass helium-core white-dwarf models with stellar masses between 0.2025 and 0.3630  M ⊙ going through CNO flashes during their early cooling phases. Results. We found that the ε mechanism due to stable hydrogen burning can excite low-order ( ℓ  = 1, 2) gravity modes with periods between ∼80 and 500 s for stars with 0.2025 ≲  M ⋆ / M ⊙  ≲ 0.3630 located in an extended region of the log g  −  T eff diagram, with effective temperature and surface gravity in the ranges 15 000 ≲  T eff  ≲ 38 000 K and 5.8 ≲ log g  ≲ 7.1, respectively. For the sequences that experience multiple CNO flashes, we found that with every consecutive flash, the region of instability becomes wider and the modes are more strongly excited. The magnitudes of the rate of period change for these modes are in the range of ∼10 −10 –10 −11  [s/s]. Conclusions. Since the timescales required for these modes to reach amplitudes large enough to be observable are shorter than their corresponding evolutionary timescales, the detection of pulsations in these stars is feasible. Given the current problems in distinguishing some stars that populate the same region of the log g  −  T eff plane, the eventual detection of short-period pulsations may help in the classification of such stars. Furthermore, if a low-mass white dwarf star were found to pulsate with low-order gravity modes in this region of instability, it would confirm our result that such pulsations can be driven by the ε mechanism. In addition, confirming a rapid rate of period change in these pulsations would support the idea that these stars actually experience CNO flashes, as has been predicted by evolutionary calculations. 

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5. Sleep spindles as a diagnostic and therapeutic target for chronic pain

   https://doi.org/10.1177/1744806920902350  

   Caravan, Bassir; Hu, Lizbeth; Veyg, Daniel; Kulkarni, Prathamesh; Zhang, Qiaosheng; Chen, Zhe_S; Wang, Jing (January 2020, Molecular Pain)

   Pain is known to disrupt sleep patterns, and disturbances in sleep can further worsen pain symptoms. Sleep spindles occur during slow wave sleep and have established effects on sensory and affective processing in mammals. A number of chronic neuropsychiatric conditions, meanwhile, are known to alter sleep spindle density. The effect of persistent pain on sleep spindle waves, however, remains unknown, and studies of sleep spindles are challenging due to long period of monitoring and data analysis. Utilizing automated sleep spindle detection algorithms built on deep learning, we can monitor the effect of pain states on sleep spindle activity. In this study, we show that in a chronic pain model in rodents, there is a significant decrease in sleep spindle activity compared to controls. Meanwhile, methods to restore sleep spindles are associated with decreased pain symptoms. These results suggest that sleep spindle density correlates with chronic pain and may be both a potential biomarker for chronic pain and a target for neuromodulation therapy. 

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