The evolution of the transboundary Evros river delta (Northeast Aegean Sea) under human intervention: a seven-decade analysis

The Evros deltaic plain (North Aegean Sea, Greece) covers an area of 188 km2 and is shared by Greece and Turkey by its current main channel. This paper investigates deltaic plain evolution during the last seven decades (1945–2017), taking into consideration human interventions and their impacts on deltaic processes. Outcomes indicate that the construction of more than 25 major dams in the Evros River catchment resulted in >80% reduction in fluvial suspended load. Moreover, the alignment and relocation of the main distributary channel to the southeast was accompanied by the transformation of >40% of the deltaic plain to agricultural land. The combination of human interventions supports the coastline advance of the active main mouth (current rate of 3.9 *10−3 km2/yr), retreat of the old (abandoned) Evros mouth (current rate 7.7 *10−3 km2/yr), and signs of remarkable vulnerability in the middle mouth area. © 2019 Informa UK Limited, trading as Taylor & Francis Group

Daytime somnolence as an early sign of cognitive decline in a community-based study of older people

Objective This study aimed to examine the association between self-reported sleep problems and cognitive decline in community-dwelling older people. We hypothesized that daytime somnolence predicts subsequent cognitive decline. Methods This is a longitudinal study in a 3.2-year follow-up, with 18-month intervals. The setting is the Washington Heights-Inwood Community Aging Project. There were 1098 participants, who were over 65 years old and recruited from the community. Sleep problems were estimated using five sleep categories derived from the RAND Medical Outcome Study Sleep Scale: sleep disturbance, snoring, awaken short of breath/with a headache, sleep adequacy, and daytime somnolence. Four distinct cognitive composite scores were calculated: memory, language, speed of processing, and executive functioning. We used generalized estimating equations analyses with cognitive scores as the outcome, and time, sleep categories and their interactions as the main predictors. Models were initially unadjusted and then adjusted for age, gender, education, ethnicity, depression, and apolipoprotein E-ε4 genotype. Results Increased daytime somnolence (including feeling drowsy/sleepy, having trouble staying awake, and taking naps during the day) was linked to slower speed of processing both cross-sectionally (B = -0.143, p = 0.047) and longitudinally (B = -0.003, p = 0.027). After excluding the demented participants at baseline, the results remained significant (B = -0.003, p = 0.021). Conclusions Our findings suggest that daytime somnolence may be an early sign of cognitive decline in the older population. Copyright © 2015 John Wiley & Sons, Ltd

Dataset on the associations between sleep quality/duration and cognitive performance in cognitively healthy older adults

In the present data, we provide the details of the cross-sectional study examining the associations between sleep quality/sleep duration and cognitive performance. Data are from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). A total of 1484 older adults (65 y.o. or older) took part in the study. Sleep measurements were drawn from the sleep scale of the Medical Outcomes Study (MOS). Cognition was used as a z-score drawn by different tests. The domains examined were: executive function, visuo-spatial ability, language, attention- speed of processing, as well as the composite z-score of all the cognitive domains (including memory). Linear regression models were conducted to investigate the associations between sleep quality and cognition, and sleep duration and cognition as well. We also conducted linear regression analyses for the associations between sleep quality/duration and cognitive domains/composite cognitive score based on the status of the Apolipoprotein E-ε4 (ApoE-ε4) genotype. Analyses were performed excluding both the demented and the Mild Cognitive Impairment (MCI) participants. Adjustments conducted for multiple covariates. For further analyses and enhanced discussion, see original article: “Sleep quality and duration in relation to memory in the elderly: initial results from the Hellenic Longitudinal Investigation of Aging and Diet” by Tsapanou et al. [1] © 201

Self-reported sleep disordered breathing as risk factor for mortality in the elderly

Background This study aimed to examine the association between self-reported sleep disordered breathing (SDB) ("awaken short of breath or with a headache") and mortality in a large and ethnically diverse group of community-dwelling elderly people. Methods A total of 1288 participants, 65 years and older, were examined longitudinally. Sleep problems were estimated using the Medical Outcomes Study Sleep Scale examining sleep disturbance, snoring, awaken short of breath or with a headache, sleep adequacy, and sleep somnolence. Cox regression analysis was used to examine the association between sleep problems and mortality. Age, gender, education, ethnicity, and body mass index were included as covariates. In further analyses we included hypertension, diabetes, heart disease, and stroke as additional covariates. Results The participants were followed for up to 6 years (mean = 2.9, standard deviation = 1.1), and 239 (18.6%) participants died during the follow-up. In unadjusted models, SDB at the initial visit was associated with mortality (hazard ratio [HR] = 1.37; 95% confidence interval [CI] 1.21-1.55; P <.0001). After adjusting for all the covariates, the relationship between SDB and mortality remained significant (HR = 1.48; 95% CI 1.29-1.70; P <.0001). Participants with Caribbean-Hispanic ancestry have higher risk for mortality. Conclusions Our results suggest that SDB is a risk factor for mortality in a large and ethnically diverse group of older adults, independent of demographic and clinical factors. Further research is needed to examine the underlying mechanisms of this association. © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved

Sleep quality and duration in relation to memory in the elderly: Initial results from the Hellenic Longitudinal Investigation of Aging and Diet

Background Sleep is crucial for cognition, particularly for memory, given its complex association with neurodegenerative processes. The aim of the present study was to examine the association between sleep quality as well as sleep duration and memory performance in a Greek elderly population. Setting Cross-sectional design in the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD), a population representative study of Greek elderly (65 years or older). Methods Data from 1589 participants free of sleep medication were included. Sleep quality was estimated by using the Sleep Scale from the Medical Outcomes Study. An extensive neuropsychological assessment examining memory was administered to each participant. Linear regression analyses were used to examine whether sleep quality (higher score, poor quality) and/or sleep duration were associated with memory expressed in the form of a z-score. Age, sex, education, and body mass index were included as covariates. The main analyses were conducted first on the total sample, then with the exclusion of demented participants, and finally with the exclusion of both demented and participants with Mild Cognitive Impairment (MCI). We then conducted further analyses on the non-demented, non-MCI group, initially stratified by Apolipoprotein E-ε4 gene. We further examined the role of co-morbidities, as well as the association between sleep duration groups and memory. We also explored any interaction effect between sex and sleep quality/duration on memory. We then examined the associations between components of sleep measures and memory scores. Lastly, we examined the associations between sleep quality/duration and verbal/non-verbal memory separately. Results In the total sample, we noted significant associations between sleep duration and memory (B = −0.001, p ≤ 0.0001), but not for sleep quality and memory (B = −0.038, p = 0.121). After excluding the demented participants, the associations were significant for: sleep quality and memory (B = −0.054, p = 0.023), and sleep duration and memory (B = −0.001, p ≤ 0.0001). After excluding both the MCI and the demented subjects, the associations between sleep quality and memory (B = −0.065, p = 0.006), and sleep duration and memory (B = −0.001, p = 0.003) were still significant. The association between the sleep duration groups and memory function was also significant, such that poor memory performance was associated with the longer sleep duration group. The results remained significant even after controlling for the co-morbidities, as well as after adding in the model anxiety and depression as covariates. Associations between sleep quality and memory, and sleep duration and memory were present in the ApoE-ε4 non-carriers. The individual sleep questions that were probably shown to be driving the associations between sleep and memory were: time to fall asleep, sleep not quiet, getting enough sleep to feel rested upon waking in the morning, and getting the amount of sleep needed. Sleep duration was associated with both verbal and non-verbal memory, while sleep quality was only associated with verbal memory. Conclusion Poor sleep quality and longer sleep duration were linked to low memory performance, independent of demographic and clinical factors, in a large sample of cognitively healthy older Greek adults. Other parameters than sleep and memory measurements could play an important role on the association. Levels of melatonin, or circadian rhythms dysregulation might play a crucial role in the above associations. © 2017 Elsevier Inc

Evaluating ocean-color algorithms to remotely sense the surface suspended particle matter in the northeast Aegean Sea, Greece

Oceanographic investigations have significantly benefited from multispectral satellite products that simplify monitoring in coastal regions thanks to their high spatial-temporal resolution. The surface Suspended Particulate Matter (SPM) is an important water quality parameter which can be derived from empirical or analytical algorithms by using the atmospherically-corrected remotely sensed reflectance R (2.) retrieved from satellite imagery. In this study, in situ SPM and R (2.) data were collected in the Gulf of Alexandroupolis, Northeastern Aegean Sea in Greece (Eastern Mediterranean Sea) during low discharge period (June 2016). We attempt to compute remotely sensed reflectance from Landsat OLI8 imagery, in order to quantify surface SPM concentrations via both a Semi-Analytical and a Multi-Band Empirical Algorithm. When comparing the satellite estimations against the field measurements, both algorithm approaches provide a non absolute correlation with in situ R (-20-30 % offset). As a result, a generic semi-analytical equation for Alexandroupolis Gulf is developed, following algorithm calibration in low turbidity waters. The proposed algorithm can be then equally implemented to the new Sentinel-2A sensor, in order to assess its variations against Landsat 8 and to determine the applicability extend of our approach

Coupling remote sensing data with in-situ optical measurements to estimate suspended particulate matter under the Evros river influence (North-East Aegean sea, Greece)

Monitoring the riverine output of Suspended Particulate Matter (SPM) distribution in marine embayment is a crucial factor for the water quality of neighbouring coastal regions. This study presents satellite-derived SPM calculations against in-situ measurements in the continental shelf of North-East Aegean surrounding the transboundary Evros river mouth. Surface SPM, Inherent Optical Properties (IOPs) and remote sensing reflectance (Rrs) data were collected in a field campaign during low river discharge period (June 2016). The relationship between the optical backscattering coefficient (bbp) and the in-situ SPM concentrations was investigated. Subsequently, an empirical single band model was applied for estimating SPM concentrations by using the Landsat-8 Operational Land Imager (L8/OLI) red band and the model was then locally tuned within the study area. Furthermore, a multi-band SPM-retrieval algorithm was developed using the in-situ surface reflectance Rrs for calibration and it was validated using the Leave-One-Out Cross Validation technique (LOOCV). The relationship between in-situ SPM and backscattering coefficient values showed good proportionality, thus, nominating the predominance of terrestrial mineral particles. Validation against field measurements indicated that the SPM concentrations derived from the newly-developed multi-band algorithm had an improved significance correlation (96%), compared to both the single band model (not-tuned) (coefficient of determination, R2 = 0.82) and its locally tuned version (R2 = 0.83). Most importantly, the generated multi-band model apart from exhibiting the best performance (R2 = 0.93), it revealed high SPM spots which were not detected by the locally tuned single band model, indicating additional processes originating from river outflows, coastal erosion and subaqueous thermal springs in the area. In contrast, the locally tuned single band model overestimated SPM values in offshore waters, where low concentrations are encountered under the influence of the clear Black Sea Water (BSW). © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group

Examining the association between Apolipoprotein E (APOE) and self-reported sleep disturbances in non-demented older adults

We aimed to examine the association between Apolipoprotein E (APOE) and sleep disturbances. This is a cross-sectional study, from the Washington Heights-Inwood Community Aging Project (WHICAP). A total of 1944 non-demented older adults took part in the study. Sleep dysfunction was measured using sleep categories derived from the Medical Outcomes Study Sleep Scale. Genetic association between APOE-ε4 genotype and sleep disturbances was assessed using unadjusted linear regression models. Secondary analyses were conducted adjusting for age, sex, education, ethnicity and body mass index (BMI). In the unadjusted model, individuals carrying the APOE-ε4 allele showed lower levels of snoring (β = -0.02, SE = 0.01, p = 0.010) and sleep apnea (β = -0.01, SE = 0.01, p = 0.037) when compared to non-ε4 carriers. After covariates' adjustment, ε4 carriers demonstrated stronger association with lower levels of both snoring (β = -0.02, SE = 0.01, p = 0.006), and sleep apnea (β = -0.01, SE = 0.01, p = 0.018). Our results suggest that APOE-ε4 is associated with decreased problems in snoring and sleep apnea, in non-demented older adults. © 2015 Elsevier Ireland Ltd

Data from a cross-sectional study on Apolipoprotein E (APOE-ε4) and snoring/sleep apnea in non-demented older adults

In the present data, we provide the details of the cross-sectional study, from the Washington Heights-Inwood Community Aging Project (WHICAP) that examined the association between Apolipoprotein E (APOE-ε4) and snoring/sleep apnea. A total of 1944 non-demented older adults constituted our sample. Sleep dysfunction was measured using sleep categories derived from the Medical Outcomes Study Sleep Scale. Stratified analyses were conducted in order to examine the association between APOE-ε4 and sleep variables by ethnic group. For further analyses and enhanced discussion, see ". Examining the association between Apolipoprotein E (APOE) and self-reported sleep disturbances in non-demented older adults" by Tsapanou et al. (2015) [1]. © 2015 The Authors