Ionospheric day‐to‐day variability is essential for understanding the space environment, while it is still challenging to properly quantify and forecast. In the present work, the day‐to‐day variability of F2 layer peak electron densities (NmF2) is examined from both observational and modeling perspectives. Ionosonde data over Wuhan station (30.5°N, 114.5°E; 19.3°N magnetic latitude) are compared with simulations from the specific dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (SD‐WACCM‐X) and the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) in 2009 and 2012. Both SD‐WACCM‐X and TIEGCM are driven by the realistic 3 h geomagnetic index and daily solar input, and the former includes self‐consistently solved physics and chemistry in the lower atmosphere. The correlation coefficient between observations and SD‐WACCM‐X simulations is much larger than that of the TIEGCM simulations, especially during dusk in 2009 and nighttime in 2012. Both the observed and SD‐WACCM‐X simulated day‐to‐day variability of NmF2 reveal a similar day‐night dependence in 2012 that increases large during the nighttime and decreases during the daytime, and shows favorable consistency of daytime variability in 2009. Both the observations and SD‐WACCM‐X simulations also display semiannual variations in nighttime NmF2 variability, although the month with maximum variability is slightly different. However, TIEGCM does not reproduce the day‐night dependence or the semiannual variations well. The results emphasize the necessity for realistic lower atmospheric perturbations to characterize ionospheric day‐to‐day variability. This work also provides a validation of the SD‐WACCM‐X in terms of ionospheric day‐to‐day variability.
This content will become publicly available on April 1, 2025
The relationship between the early‐age activity of Mediterranean fruit flies (medflies) or other fruit flies and their lifespan has not been much studied, in contrast to the connections between lifespan and diet, sexual signaling, and reproduction. The objective of this study is to assess intra‐day and day‐to‐day activity profiles of female Mediterranean fruit flies and their role as biomarker of longevity as well as to explore the relationships between these activity profiles, diet, and age‐at‐death throughout the lifespan. We use advanced statistical methods from functional data analysis (FDA). Three distinct patterns of activity variations in early‐age activity profiles can be distinguished. A low‐caloric diet is associated with a delayed activity peak, while a high‐caloric diet is linked with an earlier activity peak. We find that age‐at‐death of individual medflies is connected to their activity profiles in early life. An increased risk of mortality is associated with increased activity in early age, as well as with a higher contrast between daytime and nighttime activity. Conversely, medflies are more likely to have a longer lifespan when they are fed a medium‐caloric diet and when their daily activity is more evenly distributed across the early‐age span and between daytime and nighttime. The before‐death activity profile of medflies displays two characteristic before‐death patterns, where one pattern is characterized by slowly declining daily activity and the other by a sudden decline in activity that is followed by death.
more » « less- PAR ID:
- 10513257
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Aging Cell
- Volume:
- 23
- Issue:
- 4
- ISSN:
- 1474-9718
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Diet is a key factor of human health, and additional research is needed in order to understand the psychological causes, consequences, and moderators of dietary behavior. Participants in two studies in the United States completed a 21-day intervention that involved either self-monitoring their fruit and vegetable consumption or self-monitoring combined with earning monetary incentives for behavior. Each day, participants reported their stress, affect, and consumption of fruits and vegetables. Hierarchical linear mixed effects model results suggest that on average, daily reports of higher stress were associated with fewer fruits and vegetables consumed on that day. This effect was moderated by incentive condition, such that the relationship between stress and fruit and vegetable consumption was reduced among incented participants. There was also a marginal negative effect of time on consumption of fruits and vegetables, but this was also significantly moderated by condition, such that those participants who did not receive incentives decreased their daily servings, while incented participants did not decrease over the course of the intervention. These studies suggest that incentives may be a novel method for buffering against the negative effect of daily stress on eating a healthy diet.
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null (Ed.)Critical care patients experience varying levels of pain during their stay in the intensive care unit, often requiring administration of analgesics and sedation. Such medications generally exacerbate the already sedentary physical activity profiles of critical care patients, contributing to delayed recovery. Thus, it is important not only to minimize pain levels, but also to optimize analgesic strategies in order to maximize mobility and activity of ICU patients. Currently, we lack an understanding of the relation between pain and physical activity on a granular level. In this study, we examined the relationship between nurse assessed pain scores and physical activity as measured using a wearable accelerometer device. We found that average, standard deviation, and maximum physical activity counts are significantly higher before high pain reports compared to before low pain reports during both daytime and nighttime, while percentage of time spent immobile was not significantly different between the two pain report groups. Clusters detected among patients using extracted physical activity features were significant in adjusted logistic regression analysis for prediction of pain report group.more » « less
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Abstract Objectives Availability of fruit is an important factor influencing variation in great ape foraging strategies and activity patterns. This study aims to quantify how frugivory influences activity budgets across age‐sex classes of mountain gorillas in Bwindi Impenetrable National Park, Uganda.
Materials and methods Daily proportions of fruit‐feeding and activity budgets were calculated using 6 years of observational data on four habituated groups. We fitted generalized linear mixed models to test for age‐sex differences in the amount of fruit‐feeding, and to test whether these factors influence the proportion of time spent feeding, resting, and traveling.
Results Bwindi mountain gorillas spent on average 15% of feeding time consuming fruit, with monthly variation ranging from 0 to 70%. Greater amounts of fruit‐feeding were associated with more time feeding and traveling, and less time resting. Immatures tended to spend more feeding time on fruit than adults, but less overall time feeding and more time traveling. There were no significant differences in the amount of fruit‐feeding and overall feeding time between adult females and silverback males, despite differences in body size.
Discussion This study confirms that gorillas are frugivorous, and only the Virunga mountain gorilla population can be characterized as highly folivorous. Along with other frugivorous great apes, Bwindi mountain gorillas alter their activity patterns in response to varying amounts of fruit in their diet. A better understanding of how variable ecological conditions can drive diversity even within a subspecies has important implications for understanding relationships between ecology, body size, and foraging strategies in great apes.
