Daily Fluctuations Research Articles

Less inhibited and more depressed? The puzzling association between mood, inhibitory control and depressive symptoms

BackgroundInhibitory control (IC) deficits have been proposed as a potential risk factor for depression. However, little is known about the intra-individual daily fluctuations in IC, and its relationship to mood and depressive symptoms. Here, we examined the everyday association between IC and mood, in typical adults with various levels of depressive symptoms. MethodsParticipants (N = 106) reported their depressive symptoms and completed a Go-NoGo (GNG) task measuring IC at baseline. Then, they completed a 5-day ecological-momentary-assessment (EMA) protocol, in which they reported their current mood and performed a shortened GNG task twice/day using a mobile app. Depressive symptoms were measured again following the EMA. Hierarchical-linear-modeling (HLM) was applied to examine the association between momentary IC and mood, with post-EMA depressive symptoms as a moderator. ResultsIndividuals with elevated depressive symptoms demonstrated worse and more variable IC performance over the EMA. In addition, post-EMA depressive symptoms moderated the association between momentary IC and daily mood, such that reduced IC was associated with more negative mood only for those with lower, but not higher, symptoms. LimitationsFuture investigations should examine the validity of these outcomes in clinical samples, including patients with Major Depressive Disorder. ConclusionsVariable, rather than mere reduced, IC, is related to depressive symptoms. Moreover, the role of IC in modulating mood may differ in non-depressed individuals and individuals with sub-clinical depression. These findings contribute to our understanding of IC and mood in real life and help account for some of the discrepant findings related to cognitive control models of depression.

Daily Fluctuations In Feelings Of State Shame Are Associated With Greater Daily Pain Severity And Interference

Daily Fluctuations In Feelings Of State Shame Are Associated With Greater Daily Pain Severity And Interference

How followers' neuroticism buffers the role of the leader in their daily mental health via daily positive affect: A multilevel approach

This study expands on the existing research on employees' work-related mental health by analyzing (1) the relationship between within-person fluctuations in perceived leadership effectiveness and positive affect and mental health and (2) between-person variations in neuroticism as a relevant boundary condition of this relationship. Multilevel data was collected from 224 working adults (2240 measurement occasions). The results demonstrated that fluctuations in the perception of the leader's effectiveness were positively related to daily positive affect, and this relationship was moderated by the followers' levels of neuroticism, in such a way that higher levels of neuroticism buffered the positive effect of leadership effectiveness on positive affect. The findings also evidenced a positive relationship between daily positive affect and daily mental health, as well as a significant indirect effect from perceived leadership effectiveness to daily fluctuations in mental health via daily fluctuations in positive affect. An effective leader makes employees feel more positive affect during the day, which is beneficial to their daily mental health; however, this relationship is may be impaired by the employees' levels of neuroticism. Practical implications for theory and practice are discussed.

Daily relationships between job insecurity and emotional labor amid COVID-19: Mediation of ego depletion and moderation of off-job control and work-related smartphone use.

The economic recession in the service sector during the COVID-19 pandemic has jeopardized service employees' job security. While the daily fluctuations of perceived job insecurity may have implications for service employees' emotional labor, the day-to-day relationship between these two variables and their mediating and moderating mechanisms in the pandemic context remain unknown. To fill this gap, our research examined the day-level relationship between job insecurity perceptions, ego depletion, and emotional labor, as well as the moderating effects of overnight off-job control and work-related smartphone use. To assess these relationships, we conducted two daily studies during the COVID-19 pandemic. In study 1 (March-April 2020), 135 service employees responded to morning and evening online surveys for five workdays. In study 2 (June 2022), which administered morning and evening online surveys to 90 flight attendants for five workdays, work-related COVID-19 exposure risk was controlled in the analyses. The results of the two studies demonstrated that on a day when service employees perceived a high level of job insecurity, they felt ego-depleted, which, in turn, was associated with decreased deep acting and increased surface acting. Post hoc findings indicated a significant three-way interaction between off-job control, off-job work-related smartphone use, and daily job insecurity, such that the job insecurity-ego depletion-emotional labor was most pronounced when off-job control was low and off-job work-related smartphone use was high. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Modelling Escherichia coli removal during domestic wastewater treatment in outdoor pilot scale High Rate Algal Ponds

While there is growing evidence that High Rate Algal Ponds (HRAPS) can support disinfection during wastewater treatment, the mechanisms of pathogen removal involved remain unclear. Based on previous findings, the present study aimed at verifying the occurrence and significance of dark decay, alkaline-pH toxicity, and sunlight direct damage in conditions representative of ‘real’ HRAP operation. For this purpose, Escherichia coli cell count was monitored hourly during 24 h periods in outdoor pilot HRAPs fed domestic wastewater. The data generated was used to create 2 distinct data sets that were then used to calibrate and validate a model of E. coli removal in HRAP. By modelling the contribution of the three mechanisms considered, E. coli removal in HRAPs could be predicted with a mean relative absolute error of 5.34% (N = 46). The model was then inputted yearly environmental data obtained from the continuous operations of the pilot scale HRAPs to evaluate the yearlong contributions from each mechanism to overall E. coli removal. Dark decay was thus predicted to support the highest yearlong mean contribution (78.6 – 91.0% of total E. coli decay, at the 95% confidence level) followed by sunlight mediated disinfection (6.01 – 17.8%) and pH toxicity (0.22 – 6.2%). Significant seasonal and daily fluctuations of decay mechanism contributions were evidenced in this study.

Medium-term ionospheric response to the solar and geomagnetic conditions at low-latitude stations of the East African sector

In this study, we used GPS-TEC measurements from six stations in East Africa located in low/equatorial latitudes to investigate medium-term ionospheric response to solar and geomagnetic circumstances during 2014–2016. Daily mean solar proxies (F10.7 and SSN) and geomagnetic activity indices (Kp and Dst) were used to determine solar and geomagnetic activity effects on ionospheric vertical Total-Electron-Content (vTEC). We have applied statistical analysis and quadratic fits with solar indices to find the type of trends, forecast vTEC, and describe the daily fluctuations of vTEC. Asab and Debark had the highest vTEC values among the six stations during the months of equinoxes in which they are located at 13.060 and 130 geographic latitudes, respectively. The highest vTEC values were 86, 80, and 75 TECU in March, October, and April 2014, respectively; 72 TECU in March and April 2015, and 70 TECU in February 2015. Within 24 hours, the magnitudes of vTEC were greater in February, March, and April 2014, 2015, and 2016 than in the remaining months. The changes in vTEC have demonstrated good agreement with the trend of solar parameters, and F10.7 has a stronger correlation with vTEC than SSN by 20%. The effects of solar activity on GPS-vTEC were positive, whereas the vTEC was disturbed during the storm’s main and recovery phases, which led to positive and negative ionospheric effects, respectively. We found both linear and non-linear trends. Nevertheless, when we approximated (F10.7)2 and (SSN)2 coefficients, linear trends in vTEC were dominant. The anticipated and observed vTEC measurements are in moderately good agreement.

Brain temperature remains stable during the day: a study of diffusion-weighted imaging thermometry in healthy individuals.

To investigate the daily fluctuations in brain temperature in healthy individuals using magnetic resonance (MR) diffusion-weighted imaging (DWI) thermometry and to clarify the associations between the brain and body temperatures and sex. Thirty-two age-matched healthy male and female volunteers (male = 16, 20-38 years) were recruited between July 2021 and January 2022. Brain MR examinations were performed in the morning and evening phases on the same day to calculate the brain temperatures using DWI thermometry. Body temperature was also measured in each MR examination. Group comparisons of body and brain temperatures between the two phases were performed using paired t-tests. A multiple linear regression model was used to predict the morning brain temperature using sex, evening brain temperature, and the interaction between sex and evening brain temperature as covariates. Body temperatures were significantly higher in the evening than in the morning in all participants, male group, and female group (p < 0.001, = 0001, and < 0.001, respectively). Meanwhile, no significant difference was observed between the morning and evening brain temperatures in each analysis (p = 0.23, 0.70, and 0.16, respectively). Multiple linear regression analysis showed significant associations of morning brain temperature with sex (p = 0.038), evening brain temperature (p < 0.001), and the interaction between sex and evening brain temperature (p = 0.036). Unlike body temperature, brain temperature showed no significant daily fluctuations; however, daily fluctuations in brain temperature may vary depending on sex.

Medium-term forecast of daily passenger volume of high speed railway based on DLP-WNN

PurposeThis paper aims to propose a medium-term forecast model for the daily passenger volume of High Speed Railway (HSR) systems to predict the daily the Origin-Destination (OD) daily volume for multiple consecutive days (e.g. 120 days).Design/methodology/approachBy analyzing the characteristics of the historical data on daily passenger volume of HSR systems, the date and holiday labels were designed with determined value ranges. In accordance to the autoregressive characteristics of the daily passenger volume of HSR, the Double Layer Parallel Wavelet Neural Network (DLP-WNN) model suitable for the medium-term (about 120 d) forecast of the daily passenger volume of HSR was established. The DLP-WNN model obtains the daily forecast result by weighed summation of the daily output values of the two subnets. Subnet 1 reflects the overall trend of daily passenger volumes in the recent period, and subnet 2 the daily fluctuation of the daily passenger volume to ensure the accuracy of medium-term forecast.FindingsAccording to the example application, in which the DLP-WNN model was used for the medium-term forecast of the daily passenger volumes for 120 days for typical O-D pairs at 4 different distances, the average absolute percentage error is 7%-12%, obviously lower than the results measured by the Back Propagation (BP) neural network, the ELM (extreme learning machine), the ELMAN neural network, the GRNN (generalized regression neural network) and the VMD-GA-BP. The DLP-WNN model was verified to be suitable for the medium-term forecast of the daily passenger volume of HSR.Originality/valueThis study proposed a Double Layer Parallel structure forecast model for medium-term daily passenger volume (about 120 days) of HSR systems by using the date and holiday labels and Wavelet Neural Network. The predict results are important input data for supporting the line planning, scheduling and other decisions in operation and management in HSR systems.

Effects of daily thermal fluctuations on the Atlantic silverside, a fish with temperature-dependent sex determination.

Temperature-dependent sex determination (TSD) occurs when the temperature during development affects gonad determination. Historically, most work on TSD in fishes was conducted under constant temperatures, yet daily fluctuating temperatures can significantly alter fish physiology and life history. Thus, we subjected the Atlantic silverside, Menidia menidia (a TSD species), to 28, 28 ± 2 and 28 ± 4°C (a high, masculinizing temperature) and quantified sex ratios and length. We found that the percentage of females increased by 60%-70% when the fish were exposed to daily fluctuating temperatures (from 10% to 16% and 17% under fluctuations).

Adverse effects of the pesticide chlorpyrifos on the physiology of a damselfly only occur at the cold and hot extremes of a temperature gradient

Ecotoxicological studies considerably improved realism by assessing the toxicity of pollutants at different temperatures. Nevertheless, they may miss key interaction patterns between pollutants and temperature by typically considering only part of the natural thermal gradient experienced by species and ignoring daily temperature fluctuations (DTF). We therefore tested in a common garden laboratory experiment the effects of the pesticide chlorpyrifos across a range of mean temperatures and DTF on physiological traits (related to oxidative stress and bioenergetics) in low- and high-latitude populations of Ischnura elegans damselfly larvae. As expected, the impact of chlorpyrifos varied along the wide range of mean temperatures (12–34 °C). None of the physiological traits (except the superoxide anion levels) were affected by chlorpyrifos at the intermediate mean temperatures (20–24 °C). Instead, most of them were negatively affected by chlorpyrifos (reduced activity levels of the antioxidant defense enzymes superoxide dismutase [SOD], catalase [CAT] and peroxidase [PER], and a reduced energy budget) at the very high (≥28 °C) or extreme high temperatures (≥32 °C), and to lesser extent at the lower mean temperatures (≤16 °C). Notably, at the lower mean temperatures the negative impact of chlorpyrifos was often only present or stronger under DTF. Although the chlorpyrifos effects on the physiological traits greatly depended on the experimentally imposed thermal gradient, patterns were mainly consistent across the natural latitude-associated thermal gradient, indicating the generality of our results. The thermal patterns in chlorpyrifos-induced physiological responses contributed to the observed toxicity patterns in life history (reduced survival and growth at low and high mean temperatures). Taken together, our results underscore the importance of evaluating pesticide toxicity along a temperature gradient and of taking a mechanistic approach with a focus on physiology, to improve our understanding of the combined effects of pollutants and temperature in natural populations.

A comparison of daily glucose fluctuation among GCK-MODY and type 2 diabetes using continuous glucose monitoring technology.

Glucokinase variant-induced maturity-onset diabetes of the young (GCK-MODY) exhibits the unique clinical features of mild fasting hyperglycaemia. However, formal studies of its glucose excursion pattern in daily life in comparison with those with or without other types of diabetes are lacking. We conducted a case-control study including 25 patients with GCK-MODY, 25 A1c-matched, drug naive patients with type 2 diabetes (T2DM) and 25 age-, BMI- and sex-matched subjects with normal glucose tolerance (NGT). All the subjects wore flash glucose monitoring (FGM) sensors for 2 weeks, and glucose readings were masked. Glucose excursion was significantly lower in the GCK-MODY than that in A1c-matched T2DM during the daytime, but was similar during the nighttime. The daytime coefficient of variation [CV] driven by postprandial glucose could separate GCK-MODY from well-controlled T2DM, but the nighttime CV could not. In discriminating between GCK-MODY and T2DM, the area under the curve (AUC) of the CV was 0.875. However, in GCK-MODY and NGT subjects, the CVs were similar at 24h, whereas the other four excursion parameters were significantly higher in GCK-MODY than those in NGT subjects. FGM confirmed the stability and mildness of hyperglycemia in GCK-MODY patients. Postprandial regulation is a key driver of the difference in excursion between GCK-MODY and T2DM.

Smartphone-based cough monitoring as a near real-time digital pneumonia biomarker.

Cough represents a cardinal symptom of acute respiratory tract infections. Generally associated with disease activity, cough holds biomarker potential and might be harnessed for prognosis and personalised treatment decisions. Here, we tested the suitability of cough as a digital biomarker for disease activity in coronavirus disease 2019 (COVID-19) and other lower respiratory tract infections. We conducted a single-centre, exploratory, observational cohort study on automated cough detection in patients hospitalised for COVID-19 (n=32) and non-COVID-19 pneumonia (n=14) between April and November 2020 at the Cantonal Hospital St Gallen, Switzerland. Cough detection was achieved using smartphone-based audio recordings coupled to an ensemble of convolutional neural networks. Cough levels were correlated to established markers of inflammation and oxygenation. Cough frequency was highest upon hospital admission and declined steadily with recovery. There was a characteristic pattern of daily cough fluctuations, with little activity during the night and two coughing peaks during the day. Hourly cough counts were strongly correlated with clinical markers of disease activity and laboratory markers of inflammation, suggesting cough as a surrogate of disease in acute respiratory tract infections. No apparent differences in cough evolution were observed between COVID-19 and non-COVID-19 pneumonia. Automated, quantitative, smartphone-based detection of cough is feasible in hospitalised patients and correlates with disease activity in lower respiratory tract infections. Our approach allows for near real-time telemonitoring of individuals in aerosol isolation. Larger trials are warranted to decipher the use of cough as a digital biomarker for prognosis and tailored treatment in lower respiratory tract infections.

Minimization of power fluctuations of wind power plants when constructed in exclusion zones of enterprises

Purpose. Development of a methodology for selecting types and quantities of wind turbines built in exclusion zones of industrial enterprises to minimize fluctuations in the power generated by them and increase the efficiency of their use. Methodology. The work used methods of synthesis of systems, computer modeling in the calculation of the optimal number of different types of wind turbines, methods of combinatorics. Findings. The developed method for designing wind power plants built in the exclusion zones of enterprises allows determining the required number of different types of wind turbines with different capacities and nominal values ​relative to the wind speed, which will provide the necessary generated power with minimal fluctuations. This makes it possible to notably reduce the capacity required for the accumulation of excess generation and to significantly reduce the cost of implementing wind turbines. Originality. The work proposes a methodology for designing wind power plants based on various wind turbines, taking into account their type, power and wind characteristics of the area where the wind power plant is being built. It has been found that the coefficient of fluctuation of the power generated by the wind power plant built on the same type of wind turbines does not depend on the capacity of such a station, nor on the number of wind turbines used, but only on the type of the latter and the wind characteristics of the area where it was built. Practical value. Wind power plants used at enterprises have significant daily and annual fluctuations in the power generated by them. The proposed approach allows reducing fluctuations of power generated by the station, as well as increasing the amount of electricity generation in comparison with the use of the same type of wind turbines.

Increased daily temperature fluctuations exacerbate the toxicity of phenanthrene in Enchytraeus albidus (Enchytraeidae)

Temperature variability in soils is expected to increase due to the more frequent occurrence of heat waves, putting species under thermal stress. In addition, organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) are released into the environment due to anthropogenic activities. Both stressors negatively impact terrestrial organisms and may interact with each other. Here, we subjected the soil living enchytraeid, Enchytraeus albidus, to combined exposure to phenanthrene (PHE; 0, 10, 20, 40, and 80 mg kg−1 dry soil) and a range of temperature treatments (constant temperature (CT): 10, 15 and 20 °C; different mean temperature with the same daily temperature fluctuation (DTF-5): 10 ± 5, 15 ± 5 and 20 ± 5 °C; daily temperature fluctuation with the same mean, but different amplitudes (DTF-A): 20, 20 ± 2, 20 ± 5 and 20 ± 7 °C). We measured internal PHE concentration in adults and found that an increase in mean temperature significantly increased the internal PHE concentration. The production of juveniles was measured using a standardized test. We found a synergistic interaction between the temperature amplitude (DTF-A treatments) and PHE on the reproduction of E. albidus. The EC50 of reproduction decreased with increasing amplitude. These results show that the negative effects of PHE on E. albidus can be magnified if stressful temperatures are reached (although briefly) during diurnal fluctuations of soil temperature. Our results highlight the importance and inclusion of extreme thermal events in the risk assessment of pollutants.

Thermal conditions of green turtle (Chelonia mydas) nests in the largest rookery in the eastern Mediterranean

Climate change impacts on vertebrates have many implications. The thermal conditions of vertebrates during incubation are known to influence morphological, physiological, and behavioral traits. Thus, incubation temperatures have consequences for ecological and evolutionary processes, and for certain reptiles can determine sex. For oviparous reptiles, information on the thermal environment of nests is often used to estimate sex ratio, metabolic heat, and their effects on hatching success. This critical baseline information is not always available for all species in all regions, hampering our ability to design analyses that could direct future management and conservation actions. Such is the case for green turtles in the Mediterranean, which nest at many different sites but few of which have had their thermal environment documented in detail. We recorded temperature in 225 green turtle nests (between 2009 and 2013) and 12 control sites in the sand (15, 30, and 45 m distance from high tide line between 2010 and 2013) at 75 cm depth at Akyatan beach, Turkey. The mean temperature of the nests ranged from 28.4 to 33.5°C, and those experiencing high temperatures exhibited low hatching success. The observed thermal environment within the nests exhibited a narrow range relative to the control sites, with daily temperature fluctuations in nests ranging from 0.1°C up to 4.5°C. The nest temperature was strongly negatively correlated with incubation duration, while metabolic heating was highest in the last third of the incubation duration, and was significantly correlated to clutch size.

Thermal Performance Curves in a Polluted World: Too Cold and Too Hot Temperatures Synergistically Increase Pesticide Toxicity.

Ecotoxicological studies typically cover only a limited part of the natural thermal range of populations and ignore daily temperature fluctuations (DTFs). Therefore, we may miss important stressor interaction patterns and have poor knowledge on how pollutants affect thermal performance curves (TPCs), which is needed to improve insights into the fate of populations to warming in a polluted world. We tested the single and combined effects of pesticide exposure and DTFs on the TPCs of low- and high-latitude populations of Ischnura elegans damselfly larvae. While chlorpyrifos did not have any effect at the intermediate mean temperatures (20-24 °C), it became toxic (reflecting synergisms) at lower (≤16 °C, reduced growth) and especially at higher (≥28 °C, reduced survival and growth) mean temperatures, resulting in more concave-shaped TPCs. Remarkably, these toxicity patterns were largely consistent at both latitudes and hence across a natural thermal gradient. Moreover, DTFs magnified the pesticide-induced survival reductions at 34 °C. The TPC perspective allowed us to identify different toxicity patterns and interaction types (mainly additive vs synergistic) across the thermal gradient. This highlights the importance of using thermal gradients to make more realistic predictions about the impact of pesticides in a warming world and of warming in a polluted world.

Disturbance of primary producer communities disrupts the thermal limits of the associated aquatic fauna

Environmental fluctuation forms a framework of variability within which species have evolved. Environmental fluctuation includes predictability, such as diel cycles of aquatic oxygen fluctuation driven by primary producers. Oxygen availability and fluctuation shape the physiological responses of aquatic animals to warming, so that, in theory, oxygen fluctuation could influence their thermal ecology. We describe annual oxygen variability in agricultural drainage channels and show that disruption of oxygen fluctuation through dredging of plants reduces the thermal tolerance of freshwater animals. We compared the temperature responses of snails, amphipods, leeches and mussels exposed to either natural oxygen fluctuation or constant oxygen in situ under different acclimation periods. Oxygen saturation in channel water ranged from c. 0 % saturation at night to >300 % during the day. Temperature showed normal seasonal variation and was almost synchronous with daily oxygen fluctuation. A dredging event in 2020 dramatically reduced dissolved oxygen variability and the correlation between oxygen and temperature was lost. The tolerance of invertebrates to thermal stress was significantly lower when natural fluctuation in oxygen availability was reduced and decoupled from temperature. This highlights the importance of natural cycles of variability and the need to include finer scale effects, including indirect biological effects, in modelling the ecosystem-level consequences of climate change. Furthermore, restoration and management of primary producers in aquatic habitats could be important to improve the thermal protection of aquatic invertebrates and their resistance to environmental variation imposed by climate change.

Lower prospective memory is associated with higher neurocognitive dispersion in two samples of people with HIV: A conceptual replication study.

People living with HIV (PLWH) often experience deficits in the strategic/executive aspects of prospective memory (PM) that can interfere with instrumental activities of daily living. This study used a conceptual replication design to determine whether cognitive intraindividual variability, as measured by dispersion (IIV-dispersion), contributes to PM performance and symptoms among PLWH. Study 1 included 367 PLWH who completed a comprehensive clinical neuropsychological test battery, the Memory for Intentions Test (MIsT), and the Prospective and Retrospective Memory Questionnaire (PRMQ). Study 2 included 79 older PLWH who completed the Cogstate cognitive battery, the Cambridge Prospective Memory Test (CAMPROMPT), an experimental measure of time-based PM, and the PRMQ. In both studies, a mean-adjusted coefficient of variation was derived to measure IIV-dispersion using normative T-scores from the cognitive battery. Higher IIV-dispersion was significantly associated with lower time-based PM performance at small-to-medium effect sizes in both studies (mean r s =-0.30). The relationship between IIV-dispersion and event-based PM performance was comparably small in magnitude in both studies (r s =-0.19, -0.20), but it was only statistically significant in Study 1. IIV-dispersion showed very small, nonsignificant relationships with self-reported PM symptoms in both samples (r s < 0.10). Extending prior work in healthy adults, these findings suggest that variability in performance across a cognitive battery contributes to laboratory-based PM accuracy, but not perceived PM symptoms, among PLWH. Future studies might examine whether daily fluctuations in cognition or other aspects of IIV (e.g., inconsistency) play a role in PM failures in everyday life.

Clustering Analysis of Airport Traffic Similar Days Affected by Epidemic Based on HI-K-means

During the epidemic period, the daily traffic fluctuation of the airport has a strong correlation with the current control policy. The analysis of traffic similar days can provide a reference for the optimization of airport traffic management. Aiming at the analysis of traffic similar days, a clustering model of traffic similar days based on HI-K-means (Hierarchical k-means clustering algorithm) is proposed. This algorithm combines the advantages of Hierarchical clustering and the K-means clustering algorithm and makes up for the defects of the two algorithms. Taking Tianjin Binhai Airport as an example, cluster analysis is carried out. Finally, it is concluded that the three types of traffic similar days can better match the daily traffic under different policies, indicating that the model has strong availability and high accuracy.

Infectious disease ecology and evolution in a changing world.

Infectious disease ecology and evolution in a changing world.