Longitudinal associations between insomnia symptoms and all-cause mortality among middle-aged and older adults: A population-based cohort study

To date, there is no scientific consensus on whether insomnia symptoms increase mortality risk. We investigated longitudinal associations between time-varying insomnia symptoms (difficulty initiating sleep, difficulty maintaining sleep, early-morning awakening, and non-restorative sleep) and all-cause mortality among middle-aged and older adults during 14 years of follow-up. Data were obtained from 2004 through 2018 survey waves of the Health and Retirement Study in the United States for a population-representative sample of 15,511 respondents who were ≥50 years old in 2004. Respondents were interviewed biennially and followed through the end of the 2018 survey wave for the outcome. Marginal structural discrete-time survival analyses were employed to account for time-varying confounding and selection bias. Of the 15,511 cohort respondents (mean [±SD] age at baseline, 63.7 [±10.2] years; 56.0% females), 5,878 (31.9%) died during follow-up. At baseline (2004), 41.6% reported experiencing at least one insomnia symptom. Respondents who experienced one (HR=1.11; 95% CI: 1.03–1.20), two (HR=1.12; 95% CI: 1.01–1.23), three (HR=1.15; 95% CI: 1.05–1.27), or four (HR=1.32; 95% CI: 1.12–1.56) insomnia symptoms had on average a higher hazard of all-cause mortality, compared to those who were symptom-free. For each insomnia symptom, respondents who experienced difficulty initiating sleep (HR=1.12; 95% CI: 1.02–1.22), early-morning awakening (HR=1.09; 95% CI: 1.01–1.18), and nonrestorative sleep (HR=1.17; 95% CI: 1.09–1.26), had a higher hazard of all-cause mortality compared to those not experiencing the symptom. The findings demonstrate significant associations between insomnia symptoms and all-cause mortality, both on a cumulative scale and independently, except for difficulty maintaining sleep. Further research should investigate the underlying mechanisms linking insomnia symptoms and mortality.

Extent of diurnal cycle of rainfall and its intra seasonal variation over coastal Tamil Nadu during north east monsoon season

The diurnal variation of north east monsoon rainfall of coastal Tamil Nadu represented by four coastal stations Chennai Nungambakkam (Nbk), Chennai Meenambakkam (Mbk), Nagapattinam (Npt) and Pamban (Pbn) was studied in detail based on hourly rainfall data of rainy days only, for the period 1 Oct-31 Dec for the 47/48 year period 1969-2016/2017. Mean Octet rainfall and its anomaly were computed for the 8 octets 00-03,…., 21-24 hrs of the day and the anomaly was tested for statistical significance. Various analysis for the individual months of Oct, Nov, Dec and the entire period Oct-Dec were separately conducted. The basic technique of evolutionary histogram analysis supplemented by harmonic analysis of octet mean rainfall anomaly was used to detect the diurnal cycle signal. Two indices named as diurnal variation of rainfall index and coefficient of mean absolute octet rainfall anomaly representing the intensity of diurnal variation in dimensionless numbers were defined, computed and interpreted. The analysis based on the above techniques revealed that the diurnal signal which shows an early morning maximum and late afternoon minimum of octet rainfall is well defined in Oct, decreases in Nov and further decreases in Dec for all the 4 stations. Though the diurnal variation manifests a well defined pattern in Dec the signal is not statistically significant in most cases. For Nbk and Mbk there is a weak secondary peak of octet rainfall anomaly occurring in the forenoon and afternoon respectively in Oct and Dec suggesting the presence of semi-diurnal variation of rainfall. Stationwise, the diurnal signal is most well defined for each month/season in Pbn followed by Npt, Nbk and then Mbk. The physical causes behind the diurnal signal and its decrease as the north east monsoon season advances from Oct to Dec have been deliberated. The well known feature of nocturnal maximum of oceanic convection influencing a coastal station with maritime climate and the higher saturation at the lower levels of the upper atmosphere in the early morning hours have been advanced as some of the causes. For the much more complex feature of decrease of diurnal signal with the advancement of the season, the decrease of minimum surface temperature over coastal Tamil Nadu from Oct to Dec causing an early morning conceptual land breeze has been shown as one of the plausible causes based on analysis of temperature and wind. Scope for further work based on data from automatic weather stations, weather satellites and Doppler Weather Radars has been discussed.

The Spatiotemporal Evolution of the Diurnal Cycle in Two WRF Simulations of Tropical Cyclones

The properties of diurnal variability in tropical cyclones (TCs) and the mechanisms behind them remain an intriguing aspect of TC research. This study provides a comprehensive analysis of diurnal variability in two simulations of TCs to explore these mechanisms. One simulation is a well known Hurricane Nature Run, which is a realistic simulation of a TC produced using the Weather Research and Forecasting model (WRF). The other simulation is a realistic simulation produced using WRF of Hurricane Florence (2018) using hourly ERA5 reanalysis data as input. Empirical orthogonal functions and Fourier filtering are used to analyze diurnal variability in the TCs. In both simulations a diurnal squall forms at sunrise in the inner core and propagates radially outwards and intensifies until midday. At midday the upper-level outflow strengthens, surface inflow weakens, and the cirrus canopy reaches its maximum height and radial extent. At sunset and overnight, the surface inflow is stronger, and convection inside the RMW peaks. Therefore, two diurnal cycles of convection exist in the TCs with different phases of maxima: eyewall convection at sunset and at night, and rainband convection in the early morning. This study finds that the diurnal pulse in the cirrus canopy is not advectively-driven, nor can it be attributed to weaker inertial stability at night; rather, the results indicate direct solar heating as a mechanism for cirrus canopy lifting and enhanced daytime outflow. These results show a strong diurnal modulation of tropical cyclone structure, and are consistent with other recent observational and modeling studies of the TC diurnal cycle.

Biometeorological Conditions during the August 2015 Mega-Heat Wave and the Summer 2010 Mega-Heat Wave in Ukraine

The human-biometeorological conditions in Ukraine during two mega-heat waves were analyzed. The evaluation is based on physiologically equivalent temperature (PET). The calculation of PET is performed utilizing the RayMan model. The results revealed these two mega-heat waves produced strenuous human-biometeorological conditions on the territory of Ukraine. During the summer 2010 mega-heat wave, strong and extreme heat stress prevailed at about midday at the stations where this atmospheric phenomenon was observed. The mega-heat wave of August 2015 was characterized by a lower heat load. The diurnal variation of PET values during the researched mega-HW was similar to that of the diurnal variation of air temperature with minimum values in the early morning and maximum values in the afternoon. On the territory where mega-heat waves were observed, the number of days during which heat stress occurred for 9 h amounted to 97.6% for the period from 31 July to 12 August 2010 and 77.1% for the mega-heat wave of August 2015.

Affordable and effective optokinetic response methods to assess visual acuity and contrast sensitivity in larval to juvenile zebrafish

The optokinetic response (OKR) is an effective behavioural assay to investigate functional vision in zebrafish. The rapid and widespread use of gene editing, drug screening and environmental modulation technologies has resulted in a broader need for visual neuroscience researchers to access affordable and more sensitive OKR, contrast sensitivity (CS) and visual acuity (VA) assays. Here, we demonstrate how 2D- and 3D-printed, striped patterns or drums coupled with a motorised base and microscope provide a simple, cost-effective but efficient means to assay OKR, CS and VA in larval-juvenile zebrafish. In wild-type, five days post-fertilisation (dpf) zebrafish, the 2D or 3D set-ups of 0.02 cycles per degree (cpd) (standard OKR stimulus) and 100% black-white contrast evoked equivalent responses of 24.2±3.9 or 21.8±3.9 saccades per minute, respectively. Furthermore, although the OKR number was significantly reduced compared to the 0.02 cpd drum (p<0.0001), 0.06 and 0.2 cpd drums elicited equivalent responses with both set-ups. Notably, standard OKRs varied with time of day; peak responses of 29.8±7 saccades per minute occurred in the early afternoon with significantly reduced responses occurring in the early morning or late afternoon (18.5±3 and 18.4±4.5 saccades per minute, respectively). A customised series of 2D printed drums enabled analysis of VA and CS in 5-21 dpf zebrafish. The saccadic frequency in VA assays was inversely proportional to age and spatial frequency and in CS assays was inversely proportional to age and directly proportional to contrast of the stimulus. OKR, VA and CS of zebrafish larvae can be efficiently measured using 2D- or 3D-printed striped drums. For data consistency the luminance of the OKR light source, the time of day when the analysis is performed, and the order of presentation of VA and CS drums must be considered. These simple methods allow effective and more sensitive analysis of functional vision in zebrafish.

Monitoring post-release behavioural activity of captive-bred urial (Ovis vignei punjabiensis) at Togh Managara Safari Park Khyber Pakhtunkhwa, Pakistan

The Punjab urial (Ovis vignei punjabiensis) is a globally threatened wild sheep species. In Pakistan the species is legally protected and bred in captivity to release into natural habitats to reinforce wild populations. Vigilance and feeding are critical to survival, though the degree to which captive-bred animals exhibit these behaviours post-release has rarely been investigated. We monitored the daily behaviours of five adult urial after release and classifying behaviours from 0600 hrs to 1800 hrs, replicating each one-hour period twice and recording four observations of each animal per hour. At the herd level, vigilance and feeding behaviours were exhibited equally. Males and females invested equal time in feeding, males were more vigilant (p = 0.001) and more aggressive (p = 0.010), and females were more restful (p = 0.019) or engaged in grooming (p = 0.044) or locomotion (p = 0.002). Females spent more time feeding than being vigilant (p = 0.002). Males maintained high levels of vigilance throughout the day. Patterns of resting 1300 hrs to 1500 hrs and feeding in early morning and late afternoon were common for both sexes. Behaviours classified as ‘other’ were exhibited equally between sexes. Our results reveal positive indications of captive-bred urial balancing threat detection and energy acquisition post-release and exhibiting natural behaviours and activity patterns. We encourage assessment of survivorship to evaluate long-term effectiveness of captive breeding and release as a candidate restoration programme.

Extending vase life of carnation flowers by postharvest nano silver, humic acid and Aloe Vera gel treatments

Standard Carnation flowers (Dianthus caryophyllus cv. Dover) were harvested at the paint brush stage in the early morning, pre-cooled at 4° C for 6-h then moved under dry conditions to the laboratory. Flowers were weighted and treated for 24-h with silver nanoparticles (AgNPs) at 0, 5 or 10 ppm in plastic buckets. After pulsing treatments, cut flowers were transferred to 500 mL glass jars containing 300 mL of preservation solution treatments including, individually, humic acid at 200, 400 or 600 ppm and Aloe vera gel at 2.5%, 5.0% or 7.5% (w/v) till the end of the experiment (when flower color began to fade, petals began to roll). Distilled water was used for the control and to prepare the tested solutions. 2% sucrose was added to all treatments including the control. Addition of all preservatives to vase solutions significantly increased all the studied characteristics of cut flowers compared to control (distilled water, least values). Nanosilver treatments have the potential to be used as preservative solutions for improving postharvest vase life and quality of carnation flowers. An increment in vase life, relative fresh weight, vase solution uptake, flower diameter as well as total chlorophylls in leaves, total carbohydrates and total phenols in leaves and petals was observed, in addition to a decrease in bacterial counts in vase solution. Best results were obtained using 5 ppm AgNPs + 5.0% Aloe vera gel followed by 5 ppm AgNPs +7.5% Aloe vera gel solutions. Aloe vera gel, especially 5.0% level, showed better results than humic acid when used alone or combined with AgNPs. Nanosilver at 5 ppm recorded better results than 10 ppm when used as a single treatment.

Impacts of Coastal Terrain on Warm-Sector Heavy-Rain-Producing MCSs in Southern China

Warm-sector heavy rainfall in southern China refers to the heavy rainfall that occurs within a weakly-forced synoptic environment under the influence of monsoonal airflows. It is usually located near the southern coast, and is characterized by poor predictability and a close relationship with coastal terrain. This study investigates the impacts of coastal terrain on the initiation, organization and heavy-rainfall potential of MCSs in warm-sector heavy rainfall over southern China using quasi-idealized WRF simulations and terrain-modification experiments. Typical warm-sector heavy rainfall events were selected to produce composite environments that forced the simulations. MCSs in these events all initiated in the early morning and developed into quasi-linear convective systems along the coast with a prominent backbuilding process. When the small coastal terrain is removed, the maximum 12-h rainfall accumulation decreases by ~46%. The convection initiation is advanced ~2 h with the help of orographic lifting associated with flow interaction with the coastal hills in the control experiment. Moreover, the coastal terrain weakens near-surface winds and thus decreases the deep-layer vertical wind shear component perpendicular to the coast and increases the component parallel to the coast; the coastal terrain also concentrates the moisture and instability over the coastal region by weakening the boundary layer jet. These modifications lead to faster upscale growth of convection and eventually a well-organized MCS. The coastal terrain is beneficial for backbuilding convection and thus persistent rainfall by providing orographic lifting for new cells on the western end of the MCS, and by facilitating a stronger and more stagnant cold pool, which stimulates new cells near its rear edge.