Search results for "lepotila"
showing 7 items of 47 documents
Alleviating Class Imbalance Problem in Automatic Sleep Stage Classification
2022
For real-world automatic sleep-stage classification tasks, various existing deep learning-based models are biased toward the majority with a high proportion. Because of the unique sleep structure, most of the current polysomnography (PSG) datasets suffer an inherent class imbalance problem (CIP), in which the number of each sleep stage is severely unequal. In this study, we first define the class imbalance factor (CIF) to describe the level of CIP quantitatively. Afterward, we propose two balancing methods to alleviate this problem from the dataset quantity and the relationship between the class distribution and the applied model, respectively. The first one is to employ the data augmentati…
Adaptation to stressful environments : invasion success of the Colorado potato beetle (Leptinotarsa decemlineata)
2018
Biological invasions, specifically human-induced dispersals, are one of the major threats to our biodiversity and are predicted to increase. Invasive pests provide an opportunity to study whether adaptation to human-induced environments could promote invasions to other human-induced environments. One major anthropogenic selection pressure is created by pesticides, and pests can be exposed to various pesticides in their native, as well as introduced, ranges. I investigated whether exposure to anthropogenic selection (i.e. insecticides and herbicides) and exposure to multiple anthropogenic stressors selects for higher stress tolerance. I also tested whether parental prolonged diapause or inse…
Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
2018
Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.…
Longitudinal and cross-sectional associations of adherence to 24-hour movement guidelines with cardiometabolic risk
2022
This study aimed to examine 1) adherence to 24-hour movement guidelines over a 2-year follow-up in children aged 6-8 years and 2) association of this adherence with cardiometabolic risk factors. Physical activity and sleep were assessed by a monitor combining heart rate and accelerometry measurements. Screen time was reported by the parents. Body fat percentage, waist circumference, blood glucose, serum insulin, plasma lipids and blood pressure were assessed, and a cardiometabolic risk score was calculated using z-scores. Children were classified as meeting the guidelines if they had on average ≥60min/day of moderate-to-vigorous physical activity during the valid days; ≤120min/day of screen…
Plasticity in Photoperiodism : Drosophila montana Females Have a Life-Long Ability to Switch From Reproduction to Diapause
2022
Photoperiodic reproductive diapause is an essential part of female life cycle in several insect species living on high latitudes, where overwintering in reproductive stage involves high risks for survival and progeny production. The sensitive period (SP), during which photoperiodic cues can trigger the switch from direct development to diapause, can last from a few hours or days after emergence to the entire life span of females. Moreover, in some species, sexually mature females can enter post-reproductive diapause as a response to decreasing day length and/or temperature. We studied the duration of SP for diapause induction and the females’ ability to enter post-reproductive diapause at s…
Rhythmic Memory Consolidation in the Hippocampus
2022
Functions of the brain and body are oscillatory in nature and organized according to a logarithmic scale. Brain oscillations and bodily functions such as respiration and heartbeat appear nested within each other and coupled together either based on phase or based on phase and amplitude. This facilitates communication in wide-spread neuronal networks and probably also between the body and the brain. It is a widely accepted view, that nested electrophysiological brain oscillations involving the neocortex, thalamus, and the hippocampus form the basis of memory consolidation. This applies especially to declarative memories, that is, memories of life events, for example. Here, we present our vie…
Meeting the WHO 24-h guidelines among 2–6-year-old children by family socioeconomic status before and during the COVID-19 pandemic : a repeated cross…
2023
Background The World Health Organization (WHO) has developed guidelines for 24-h physical activity (PA), sedentary behaviour and sleep for young children. Lower socioeconomic status (SES) has been linked to a lower likelihood of meeting these guidelines. The outbreak of the novel coronavirus disease (COVID-19) raised concerns about young children’s opportunities to meet the guidelines. The study focused on the prevalence of meeting the WHO’s 24-h guidelines on screen time (ST), PA and sleep among 2–6-year-old children, in association with family SES, before COVID-19 outbreak in 2019, and during the pandemic in 2020 and 2021 in Finland. Methods Data were collected at three timepoints by an o…