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Predicting methane (CH4) emission from milk mid-infrared (MIR) spectra provides large amounts of data which is necessary for genomic selection. Recent prediction equations were developed using the GreenFeed system, which required averaging multiple CH4 measurements to obtain an accurate estimate, resulting in large data loss when animals unfrequently visit the GreenFeed. This study aimed to determine if calibrating equations on CH4 emissions corrected for diurnal variations or modeled throughout lactation would improve the accuracy of the predictions by reducing data loss compared with standard averaging methods used with GreenFeed data. The calibration dataset included 1 822 spectra from 235 cows (Holstein, Montbéliarde, and Abondance), and the validation dataset included 104 spectra from 46 (Holstein and Montbéliarde). The predictive ability of the equations calibrated on MIR spectra only was low to moderate (R2v = 0.22–0.36, RMSE = 57–70 g/d). Equations using CH4 averages that had been pre−corrected for diurnal variations tended to perform better, especially with respect to the error of prediction. Furthermore, pre−correcting CH4 values allowed to use all the data available without requiring a minimum number of spot measures at the GreenFeed device for calculating averages. This study provides advice for developing new prediction equations, in addition to a new set of equations based on a large and diverse population.

The hydrological dynamics and sources of karst tidal springs are difficult to capture and quantify due to fluctuations in their flow velocity. In this study, the Laolongshui (LLS) karst tidal spring in the Maocun underground river basin of Guilin City was taken as an example, with a 2-year continuous monitoring of the electrical conductivity, and water level, as well as water chemical analysis. The results showed the following: (1) discovered the variation pattern of LLS water level in different seasons, the water level fluctuates regularly on a daily scale, with a rise and fall time of 43.6 min after heavy rainfall in the rainy season, while in the dry season, it lasts for about 74–80 h. (2) Four peaks were extracted from the frequency distribution of electrical conductivity, representing the response of springwater under different rainfall conditions. (3) The annual average frequencies of the occurrence of P1, P2, P3, and P4 in terms of time are 53.82, 39.29, 6.18, and 0.72%, respectively. The results provide a new method for analyzing groundwater's source and dynamic changes in karst areas. HIGHLIGHTS Two years of automatic continuous monitoring illustrated the water level fluctuation of a typical karst tidal spring.; Explaining the forming mechanism of karst tidal springs.; The frequency distribution of conductivity quantified the source of karst water.; Providing a fast and low-cost new method for identifying karst water sources.; Enriching groundwater investigation methods and understanding of underground structures.;

Abstract Purpose Obstructive sleep apnea is a known risk factor for the progression of chronic kidney disease. To find early signs of the progression in subjects with obstructive sleep apnea., we assessed the diurnal variation of kidney biomarkers. Methods A prospective observational study was conducted at Kangwon National University Hospital, Chuncheon, South Korea. All participants underwent in-laboratory polysomnography and phlebotomy in the evening before the polysomnography and in the morning after the polysomnography. Kidney biomarkers, including serum creatinine, blood urea nitrogen, and serum cystatin C, were measured. Delta kidney biomarkers were calculated by subtracting the evening level of the biomarkers from the morning level. Results Twenty-six of 50 participants had severe obstructive sleep apnea. Delta cystatin C was significantly correlated with apnea–hypopnea index, oxygen desaturation index, and total arousal index with coefficients of -0.314, -0.323, and -0.289, respectively. In participants without severe obstructive sleep apnea, the morning cystatin C level (0.84 ± 0.11 mg/L) was significantly higher than the evening cystatin C level (0.81 ± 0.11 mg/L) (P = 0.005). With severe obstructive sleep apnea, the cystatin C levels were not different between the morning (0.85 ± 0.11 mg/L) and the evening (0.85 ± 0.10 mg/L). Conclusions Cystatin C level was increased in the morning in participants without severe obstructive sleep apnea, but not in participants with severe obstructive sleep apnea.

The sea surface skin temperature (SSTskin) is of critical importance with regard to air–sea interactions and marine carbon circulation. At present, no single remote sensor is capable of providing a gap-free SSTskin. The use of data fusion techniques is therefore essential for the purpose of filling these gaps. The extant fusion methodologies frequently fail to account for the influence of depth disparities and the diurnal variability of sea surface temperatures (SSTs) retrieved from multi-sensors. We have developed a novel approach that integrates depth and diurnal corrections and employs advanced data fusion techniques to generate hourly gap-free SST datasets. The General Ocean Turbulence Model (GOTM) is employed to model the diurnal variability of the SST profile, incorporating depth and diurnal corrections. Subsequently, the corrected SSTs at the same observed time and depth are blended using the Markov method and the remaining data gaps are filled with optimal interpolation. The overall precision of the hourly gap-free SSTskin generated demonstrates a mean bias of −0.14 °C and a root mean square error of 0.57 °C, which is comparable to the precision of satellite observations. The hourly gap-free SSTskin is vital for improving our comprehension of air–sea interactions and monitoring critical oceanographic processes with high-frequency variability.

The integrated multi-satellite retrievals for the global precipitation measurement (IMERG) data, which is the latest generation of multi-satellite fusion inversion precipitation product provided by the Global Precipitation Measurement (GPM) mission, has been widely applied in hydrological research and applications. However, the quality of IMERG data needs to be validated, as this technology is essentially an indirect way to obtain precipitation information. This study evaluated the performance of IMERG final run (version 6.0) products from 2001 to 2020, using three sets of gauge-derived precipitation data obtained from the Integrated Surface Database, China Meteorological Administration, and U.S. Climate Reference Network. The results showed a basic consistency in the spatial pattern of annual precipitation total between IMERG data and gauge observations. The highest and lowest correlations between IMERG data and gauge observations were obtained in North Asia (0.373, p < 0.05) and Europe (0.308, p < 0.05), respectively. IMERG data could capture the bimodal structure of diurnal precipitation in South Asia but overestimates a small variation in North Asia. The disparity was attributed to the frequency overestimation but intensity underestimation in satellite inversion, since small raindrops may evaporate before arriving at the ground but can be identified by remote sensors. IMERG data also showed similar patterns of interannual precipitation variability to gauge observation, while overestimating the proportion of annual precipitation hours by 2.5% in North America, and 2.0% in North Asia. These findings deepen our understanding of the capabilities of the IMERG product to estimate precipitation at the hourly scale, and can be further applied to improve satellite precipitation retrieval.

Circadian rhythms play a pivotal role in governing various physiological processes, including physical performance. However, in individuals deprived of light perception, such as the blind, these circadian rhythms face disruption. This study aimed to explore the influence of disturbed circadian rhythms on short-term maximal physical performance in children and adolescents with visual impairment. Forty-five volunteers participated in this study, comprising 17 blind, 13 visually impaired, and 15 sighted participants. The participants underwent a series of tests assessing maximal isometric strength performance across two days. To mitigate the influence of morning session fatigue on the evening results, each participant group performed in two separate testing sessions (i.e. in the morning (7:00 h) and in the evening (17:00 h)) on non-consecutive days in a randomized and counterbalanced setting, with approximately 36 h of recovery time between sessions. To mitigate the impact of inter-individual differences on mean values and to account for the influence of age and sex on the studied variables, data were normalized. The outcomes revealed a significant diurnal variation in maximal isometric strength performance among sighted individuals, with peak performance observed in the evening. This pattern aligns with their well-entrained circadian rhythm. In contrast, blind and visually impaired individuals did not display significant diurnal variation, signaling disrupted circadian rhythms due to the absence of light perception. These findings emphasize the crucial consideration of circadian rhythms in assessments of physical performance, especially among participants with visual impairments. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this review was to assess current evidence regarding changes in cognitive function according to time-of-day (TOD) and assess the key components of research design related to manuscripts of chronobiological nature. Methods: An English-language literature search revealed 523 articles through primary database searches, and 1868 via organization searches/citation searching. The inclusion criteria were met by eleven articles which were included in the review. The inclusion criteria set were healthy adult males, a minimum of two timepoints including morning and evening, cognitive measures of performance, and peer-reviewed academic paper. Results: It was established that cognitive performance varies with TOD and the degree of difference is highly dependent on the type of cognitive task with differences ranging from 9.0 to 34.2% for reaction time, 7.3% for alertness, and 7.8 to 40.3% for attention. The type of cognitive function was a determining factor as to whether the performance was better in the morning, evening, or afternoon. Conclusion: Although some studies did not establish TOD differences, reaction time and levels of accuracy were highest in the evening. This implies that cognitive processes are complex, and existing research is contradictory. Some studies or cognitive variables did not show any measurable TOD effects, which may be due to differences in methodology, subjects involved, testing protocols, and confounding factors. No studies met all requirements related to chronobiological research, highlighting the issues around methodology. Therefore, future research must use a rigorous, approach, minimizing confounding factors that are specific to examinations of TOD. [ABSTRACT FROM AUTHOR]

The present study to quantify the variations in microclimate under wheat, mustard and chickpea crops was conducted at ICAR-Indian Institute of Farming Systems Research, Modipuram, Meerut (U.P.), India. Air temperature, relative humidity and CO2 concentration below and above the canopies of wheat, mustard and chickpea were recorded at hourly interval from 07:30 to 17:30 hours at different heights (0.5 m, 1.0 m and 2.0 m) from the ground. CO2 probes like GMP-343, (Diffusion aspiration) was used to record data of CO2 concentration and HPM-75 probes was used to capture the observation of air temperature and relative humidity. Results revealed that diurnal air temperature was continuously increasing from morning to afternoon hrs and highest air temperature was recorded at 13:30 hrs (afternoon). Thereafter, air temperature decreased and reached to the lowest at 17:30 hrs irrespective of crops and height from the ground. Analysis of diurnal air temperature variations at different height clearly showed that tall statured crop such as wheat and mustard reached higher air temperature regime early (13.30 hrs) compared to short statured crop like chickpea at 15.30 hrs. Highest relative humidity was observed at 07.30 hrs and lowest relative humidity was recorded either at 13:30 hrs or at 15:30 hrs. As per study maximum CO2 concentration was found at 07:30 hrs morning and minimum at 15:30 hrs. The lowest concentration of CO2 (624 ppm) was recorded from the chickpea field and highest from the mustard field (630 ppm) at the same point of observation during vegetative phase of crops. [ABSTRACT FROM AUTHOR]

[Objective] To explore the photosynthetic characteristics and chlorophyll fluorescence characteristics of Phragmites australis in Yancheng coastal freshwater wetland. [Method] Taking Phragmites australis in Yancheng coastal freshwater wetland as the research object, the diurnal changes of photosynthetic parameters and chlorophyll fluorescence parameters of Phragmites australis in coastal freshwater wetlands were measured and compared with Phragmites australis in coastal salt marshes. [Result] The diurnal variation of net photosynthetic rate, stomatal conductance, transpiration rate and intercellular CO, concentration of Phragmites australis in the coastal freshwater wetland of Yancheng presented a double peak pattern, the diurnal variation of water use efficiency showed a "U" pattern. The diurnal variation of electron transfer rate had a downward trend as a whole, and the diurnal variation of non photochemical quenching coefficient and actual photochemical quantum efficiency presented an inverted "U" pattern and a "U" pattern, respectively. The net photosynthetic rate of Phragmites australis in coastal freshwater wetland was higher than that in coastal salt marsh wetland, and it had stronger photosynthetic capacity. [Conclusion] Compared with coastal salt marsh wetlands, Phragmites australis in Yancheng coastal freshwater wetland has stronger photosynthetic carbon fixation capacity. [ABSTRACT FROM AUTHOR]

The high-intensity partial pressure of CO2 (pCO2) in karst underground rivers rapidly releases in open-flow sections. This is an important process affecting the global karst carbon cycle. This study focuses on the diurnal variation patterns and driving factors of CO2 exchange flux at the water–air interface in the open-flow sections of typical karst underground rivers in southwestern China. The inorganic carbon in water and water–air interface exchange fluxes are observed. Three representative survey stations, i.e., the outlet of the underground river (Q1), the river sections without submerged plants (H1), and the river sections with submerged plants (H2), are selected to study the CO2 exchange process and its influencing factors. The results show that the CO2 release flux at Q1 exhibits high pressure in the daytime and low pressure in the nighttime, while H1 and H2 exhibit the opposite pattern. The photosynthesis of submerged plants significantly inhibits the carbon release flux of the river, and in the river sections where submerged plants are distributed, their biological effects have inhibited approximately 0.131 Tg C/yr of carbon emissions. This study emphasizes the significant contribution of submerged plants in restraining the release of CO2, thereby promoting carbon sequestration and storage in karst water systems. [ABSTRACT FROM AUTHOR]

As "fuel" for atmospheric photochemical reactions, volatile organic compounds (VOCs) play a key role in the secondary generation of ozone (O3) and fine particulate matter (PM2.5, an aerodynamic diameter ≤ 2.5 μm). To determine the characteristics of VOCs in a high-level ozone period, comprehensive monitoring of O3 and its precursors (VOCs and NOx) was continuously conducted in an industrial area in Shanghai from 18 August to 30 September 2021. During the observation period, the average concentration of VOCs was 47.33 ppb, and alkanes (19.64 ppb) accounted for the highest proportion of TVOCs, followed by oxygenated volatile organic compounds (OVOCs) (13.61 ppb), alkenes (6.92 ppb), aromatics (4.65 ppb), halogenated hydrocarbons (1.60 ppb), and alkynes (0.91 ppb). Alkenes were the predominant components that contributed to the ozone formation potential (OFP), while aromatics such as xylene, toluene, and ethylbenzene contributed the most to the secondary organic aerosol production potential (SOAFP). During the study period, O3, NOx, and VOCs showed significant diurnal variations. Industrial processes were the main source of VOCs, and the second largest source of VOCs was vehicle exhaust. While the largest contribution to OFP was from vehicle exhaust, the second largest contribution was from liquid petroleum gas (LPG). High potential source contribution function (PSCF) values were observed in western and southeastern areas near the sampling sites. The results of a health risk evaluation showed that the Hazard Index was less than 1 and there was no non-carcinogenic risk, but 1,3-butadiene, benzene, chloroform, 1,2-dibromoethane, and carbon tetrachloride pose a potential carcinogenic risk to the population. [ABSTRACT FROM AUTHOR]

Tennis players' success relies on tennis skills, such as groundstrokes and serves, and physical attributes, such as strength, speed and endurance. This study aimed to determine if players' tennis skills and physical attributes are influenced by time of day, chronotype or sleep–wake behaviour (SWB). Twelve male tennis players (age (years): 28.17 ± 7.85) competing in state-level competitions wore a wrist-worn activity monitor (GT3X, Actigraph) and completed a modified version of the Consensus Sleep Diary to measure SWB. The Chalder Fatigue Scale and Morningness and Eveningness Questionnaire were used to measure players' fatigue and preferred chronotype. Mid-sleep with a sleep correction was used to determine players' current chronotype. After the baseline period, players were tested at 8:00 am, 2:00 pm and 8:00 pm, with the order of testing sessions randomised for each player. Testing sessions were separated by at least 48 hours. Players' groundstrokes, serve speed, agility, overhead medicine ball throw and Hit and Turn Test performance were measured in each session. General linear modelling revealed that backhand consistency was less in the evening compared to the morning by 17% (p = 0.020) and afternoon by 15% (p = 0.040). Maximal service velocity was less in the evening compared to the afternoon by 10.5 km/h (p = 0.041). Chronotype did not influence tennis skills or physical performance. Average and maximal backhand velocities were reduced for every hour that time at lights out, and sleep-onset time was postponed. Tennis skills, but not physical performance tests, were influenced by time of day and SWB. [ABSTRACT FROM AUTHOR]

Purpose: Obstructive sleep apnea is a known risk factor for the progression of chronic kidney disease. To find early signs of the progression in subjects with obstructive sleep apnea., we assessed the diurnal variation of kidney biomarkers. Methods: A prospective observational study was conducted at Kangwon National University Hospital, Chuncheon, South Korea. All participants underwent in-laboratory polysomnography and phlebotomy in the evening before the polysomnography and in the morning after the polysomnography. Kidney biomarkers, including serum creatinine, blood urea nitrogen, and serum cystatin C, were measured. Delta kidney biomarkers were calculated by subtracting the evening level of the biomarkers from the morning level. Results: Twenty-six of 50 participants had severe obstructive sleep apnea. Delta cystatin C was significantly correlated with apnea–hypopnea index, oxygen desaturation index, and total arousal index with coefficients of -0.314, -0.323, and -0.289, respectively. In participants without severe obstructive sleep apnea, the morning cystatin C level (0.84 ± 0.11 mg/L) was significantly higher than the evening cystatin C level (0.81 ± 0.11 mg/L) (P = 0.005). With severe obstructive sleep apnea, the cystatin C levels were not different between the morning (0.85 ± 0.11 mg/L) and the evening (0.85 ± 0.10 mg/L). Conclusions: Cystatin C level was increased in the morning in participants without severe obstructive sleep apnea, but not in participants with severe obstructive sleep apnea. [ABSTRACT FROM AUTHOR]

The geographical location of Yunnan province is at the upstream area of water vapor transportation from the Bay of Bengal and the South China Sea to inland China. Understanding the spatiotemporal variations of water vapor over this region holds significant importance. We utilized the Global Navigation Satellite System (GNSS) data collected from 12 stations situated in Yunnan, which are part of the Crustal Movement Observation Network of China, to retrieve hourly precipitable water vapor (PWV) data from 2011 to 2022. The retrieved PWV data at Station KMIN were evaluated by the nearby radiosonde data, and the results show that the mean bias and RMS of the differences between the two datasets are 0.08 and 1.78 mm, respectively. Average PWV values at these stations are in the range of 11.77 to 33.53 mm, which decrease from the southwest to the north of Yunnan and are negatively correlated with the stations' heights and latitudes. Differences between average PWV in the wet season and dry season range from 12 to 27 mm. These differences tend to increase as the average PWV increases. The yearly rates of PWV variations, averaging 0.18 mm/year, are all positive for the stations, indicating a year-by-year increase in water vapor. The amplitudes of the PWV annual cycles are 9.75–20.94 mm. The spatial variation of these amplitudes is similar to that of the average PWV over the region. Generally, monthly average PWV values increase from January to July and decrease from July to December, and the growth rate is less than the decline rate. Average diurnal PWV variations show unimodal PWV distributions over the course of the day at the stations except Station YNRL, where bimodal PWV distribution was observed. [ABSTRACT FROM AUTHOR]

The present cross-sectional study aims to examine the effect of time of day on the judo-specific performance in judokas, considering their chronotypes. Twenty-four male judokas participated in the study where the Morningness-Eveningness Questionnaire was administered, and on it, they were divided into morning-type (MT:12-judokas) and evening-type groups (ET:12-judokas). Afterwards, the Special Judo Fitness Test (SJFT) was applied to both groups at three different times (morning: 09:00 h, afternoon: 13:00 h and evening: 17:00 h) with body temperature measured before and after every SJFT performance. As a result, the Group*Test Time interaction significantly affected overall throwing performance during SJFT [F(2,44) = 29.437, p = 0.001, η2p:.572]. Furthermore, a significant time effect was found for the SJFT index [F(2,44) = 5.118, p = 0.010, η2p:.189] and for the Group*Test Time interaction with the mean value of the index [F(2,44) = 24.424, p < 0.001, η2p:.526]. Furthermore, body temperature had a significant time effect [F(2,44) = 301.454, p < 0.001, η2p:.932] and the Group*Test Time interaction [F(2,44) = 5.802, p = 0.006, η2p:.209]. In conclusion, coaches and exercise experts should consider judo athletes' chronotype when planning special training programs to improve judo-specific anaerobic capacity. Furthermore, to minimize the impact of time of day and chronotype on athletes' performance in competitions, it is recommended that MT athletes develop their judo-specific anaerobic capacity in the evening hours, when their performance is lower, while ET athletes should do so in the morning hours when their performance is lower via randori training. [ABSTRACT FROM AUTHOR]

In order to study the influence of air pollutant reduction measures on aerosol water-soluble ions, and organic carbon(OC)and element carbon(EC)during the 14th National Games in Xi'an city of Shaanxi, China, real-time observation instruments were used to motor the hourly concentration of the atmospheric pollutants(PM2.5, PM10, SO2, NO2, O3 and CO), meteorological elements, and chemical composition(OC, EC and water-soluble ions)of PM2.5 from August 6 to October 1, 2021. The results show that the air pollutant reduction measures have different effects on the diurnal variations of concentrations of O3 and PM2.5, mainly caused by the influence of temperature on photochemical processes and differences in diffusion conditions. The peak concentration of O3 on sunny days during the implementation of air pollutant reduction measures is higher, last longer, and the concentration changes more rapidly. The peak concentration of PM2.5 is higher in the daytime of the sunny days before the implementation of air pollutant reduction measures, while the peak concentration is higher at night of sunny days during the implementation of air pollutant reduction measures. The air pollutant reduction measures have different effects on the chemical components in PM2.5, especially the composition of OC. On sunny days during the implementation of air pollutant reduction measures, the concentrations of NO-3, SO2-4, NH+4, Cl-, Ca2+, Na+ and NO-2 decrease by 17.9%-71.8%, and the concentrations of K+, Mg2+ and EC increase by 1.9%-13.6%, the concentration of OC on sunny days only decreases by 1.0%, but the primary organic carbon(POC)increases by 13.6%, and the secondary organic carbon(SOC)decreases by 4.7%. The NO-3/SO2-4 ratio on sunny days during the implementation of air pollutant reduction measures(0.53)is much lower than that on sunny days before the implementation of air pollutant reduction measures(1.66), indicating that the contribution of traffic source emission is significantly reduced during the implementation of air pollutant reduction measures. Rainfall has a weak scavenging effect on NO-3 and NH+4, and increases their concentrations, but it has a strong scavenging effect on K+, Mg2+, Ca2+ and Na+. NO-3, SO2-4 and NH+4 are the essential components of water-soluble ions, accounting for 90.8% of the water-soluble ions(sunny days before the implementation of air pollutant reduction measures)to 95.8%(rainy days during the implementation of air pollutant reduction measures). The diurnal variations of water-soluble ions and carbonaceous aerosols differ at different stages.The diurnal variations of NO-3, SO2-4 and NH+4 present unimodal distributions on sunny days and multimodal distributions on rainy days. [ABSTRACT FROM AUTHOR]

The aim of this brief study was to investigate the effects of repeated jump testing on performance over 2 consecutive days while considering the possibility of diurnal changes. Fourteenmale subjects and 14 recreationally active female subjects completed countermovement jump (CMJ) and squat jump (SJ) testing on 5 occasions (baseline [0,800], 5 minutes [0,820], 8 hours [1,600], 24 hours [0,800], and 32 hours [1,600]) over 32 hours. An additional rested baseline test was conducted on a separate day in the afternoon (1,600) to compare jump performance between morning and afternoon baseline values. Excluding small decreases in CMJ height at 24 hours (p50.292, Cliff's delta520.225) in male subjects and similar decreases in CMJ height at 5 minutes (p 5 0.034, Cliff's delta 5 20.245) in addition to SJ height:contraction time at 32 hours (p 5 0.126, Cliff's delta5 0.153) in female subjects, findings generally showed no changes in jump performance over multiple assessments. Squat jumpmetrics may have showed small improvements betweenmorning and afternoon baseline values inmale subjects (SJ height:contraction time [p50.030, Cliff's delta50.225]) and female subjects (SJ height [p50.013, Cliff's delta50.173] and SJ height:contraction time [p50.091, Cliff's delta50.163)]. As jump performance was largely unaffected by repeated jump testing, the present findings support the use ofmonitoring practices and research designs that require multiple jump assessments within acute periods (;32 hours). [ABSTRACT FROM AUTHOR]

Meteorological conditions and source emissions in grassland areas are quite different from those in urban areas, which significantly impacts the spatiotemporal characteristics of black carbon (BC). To obtain the characteristics of BC in the typical grassland environment in China, continuous observations of BC were carried out in Etuoke Banner, a typical grassland environment in Ordos, from September 8 to December 1, 2022. BC in Etuoke Banner in autumn is 22.4–4667.5 ng m−3, and the average concentration is 456.6 ng m−3, accounting for 2.20% of the mass fraction of PM2.5. BCliquid (BC generated from the combustion of liquid fuels) is the main component of BC (accounting for 79.2%); the average concentration is 361.7 ng m−3. The diurnal variations of BC, BCliquid, and BCsolid (BC generated from the combustion of solid fuels) are bimodal, with peaks at 08:00 and 18:00. The first peak is mainly related to traffic sources, cooking sources, and incomplete combustion of carbon‐containing substances; the second peak may be caused by emissions from residential cooking sources under the influence of meteorological conditions unfavorable to diffusion. The diurnal variation of absorption Ångström exponent (AAE) is unimodal, with the peak at 14:00. With the increase in BC mass concentration, AAE and visibility gradually decreased, wind speed first decreased and then increased, P and RH gradually increased, and the contribution of biomass combustion sources to BC decreased. In contrast, the contribution of traffic sources to BC increased. The evolution characteristics of atmospheric pollutants differed with the increase in BC concentration. The potential sources and affecting areas of BC and PM2.5 are mainly concentrated around Etuoke Banner and can affect the North China Plain after 48 h of transmission. [ABSTRACT FROM AUTHOR]

• The diurnal response of cooling power is studied during geomagnetic storms of different intensities. • The nighttime cooling power is almost half the daytime value. • Maximum enhancement in cooling power is observed within 24 h of storm's onset. The Nitric Oxide (NO) emission at 5.3 µm is the dominating thermospheric coolant in the altitude above ∼ 100 km. It effectively regulates the thermospheric temperature during space weather events. We studied the diurnal response of the Nitric Oxide at 5.3 µm emission to the geomagnetic storms of different intensities by using the NO emission data from the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard NASA's Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. We selected eight CME-driven geomagnetic storms with |SYM-H| index ranging from 0 to 500 nT. One of the storms that occurred during 19–22 November 2003 is investigated in details. Other events are used for comparison. The NO flux and the NO power during different phases of the geomagnetic storms are calculated with 24 h-time bins from the storm's onset. The NO cooling and the cooling power are always higher during the daytime. Although the NO cooling flux and the cooling power increase with the storm intensity, they are not always higher during the stronger storms. [ABSTRACT FROM AUTHOR]

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Abstract The diurnal variation and distribution of lunar surficial hydration (OH/H2O) is of great significance for understanding the solar wind implantation and water cycle on the Moon. Lunar south pole is an ideal place to study the diurnal variation of surficial hydration due to the large number of repeat observations of the same region, which is very limited in mid‐ or low‐latitudes. Here we showed clear 0.5‐hr interval diurnal variation of surficial hydration at lunar south pole. The variation of hydration band depth with local time is exactly the opposite to the variation of temperature, indicating that lunar surficial hydration changes sufficiently with temperature. This relationship indicates that both the diurnal variation and hydration content are latitude dependent. Our observations support the hypothesis that the diurnal variation of hydration on the Moon is due to the formation of metastable hydroxyl.

The present study aimed to investigate the effect of the timing of the last meal, “Suhoor”, on diurnal variation in cognitive performance during Ramadan intermittent fasting (RIF). In a randomized order, 26 adolescent female athletes (aged 15.9 ± 0.9 y) were tested in three sessions at 7:00 a.m., 12:00 p.m., and 5:00 p.m. across four different conditions: the 10 days preceding Ramadan (PR); the final 12 days of Ramadan (RO): two different conditions: Early Suhoor (SEarly), and Late Suhoor (SLate); and, ultimately, the 10 days immediately after Ramadan (AR) with an in-between recovery period of ≥24 h. During each test session, the oral temperature (OT), simple reaction time test (SRT), choice reaction time test (CRT), attention test (ATT), and mental rotation test (MRT) were evaluated. The Pittsburgh Sleep Quality Index (PSQI) and daily diary intake were assessed across the three periods. Compared to PR, the sleep parameters assessed by the PSQI were significantly lower during the RO and AR periods. However, neither total dietary intake nor OT showed any changes due to RIF. Compared to PR, the afternoon performances of SRT, CRT, ATT, and MRT significantly declined under both the SEarly and SLate conditions. Notably, midday performance decreased only during SLate, while morning performance remained unaffected in both conditions. Additionally, compared to SEarly, these performances were better during SLate in the afternoon and at midday. In summary, nutrient intake timing had a significant effect on the diurnal fluctuations in cognitive functions during Ramadan fasting, particularly around noon and in the afternoon. Our results illustrate the benefits of a late last meal (Suhoor) in preserving optimal morning cognitive abilities and preventing any impairment during the fasted state at midday or in the afternoon, which could affect overall athletic performance.

Aim of the study: Rising and falling atmospheric pressure usually heralds changes in weather conditions such as temperature, air humidity, cloud cover, precipitation, and wind speed. The work presents variations of atmospheric pressure in Siedlce from 2001 to 2022. The objective of the present work is to analyse diurnal variations in atmospheric pressure, as well as the amplitude of fluctuations and trends. Material and methods: Daily atmospheric pressure values were obtained from a meteorological station of the Institute of Meteorology and Water Management (IMGW). Diurnal changes in atmospheric pressure causing different levels of strain on the human body, ranging from weak to very strong, were identified. For each month, the number of days with specific diurnal pressure changes was calculated. The trend in monthly pressure changes was determined based on linear regression equations. Results and conclusions: The average annual atmospheric pressure at sea level in Siedlce was 1016 hPa, the lowest and the highest recorded pressure values being, respectively, 928 hPa on 25th March, 2016, and 1051 hPa on 23rd January 2006. The difference between the highest and the lowest pressure values in a given month was the greatest in January and February (40 hPa), and the lowest in August (17 hPa). The summer months of July and August, classified as weak stimulus days, exhibited the greatest diurnal variation in atmospheric pressure, while December and January were classified as very strong stimulus days, because they showed the highest variation. Monthly atmospheric pressure values in Siedlce displayed no substantial tendency to change during the study period.

In order to understand the radar climatology characteristics of convective activity over Anhui Province, the climatological distribution and influencing factors of convective activity during the warm season (May-September) were investigated using Doppler radar mosaic data from five Next Generation Weather Radars and ERA5 reanalysis data between 2015 and 2020. Results indicate that: (1) There are obvious inter-monthly variations and spatial differences of convective activity during the warm season. The convective activity peaks during the Meiyu period, with the highest frequency in June and July, followed by May and August, and the lowest in September. The region with the highest convective in July and July is mainly distributed in the southwest-northeast direction. (2) It is found that the diurnal variation of convective number is bimodally distributed in summer (June-August), with the main peak in the afternoon and a subpeak in the early morning. In June, the peak convective activity mainly occurs in the early morning, which is related to the strengthening of low-level southwest airflow from night to early morning, and thus enhancing the moisture flux convergence in Anhui. In July, the peak convective activity appears in the afternoon, with a subpeak in the early morning. Note that the main peak is stronger and the duration is longer, which is related to the enhancement of convective available potential energy in Anhui in July. The second peak in early morning is also caused by the strengthening of the low-level southwest airflow, which is similar to that in June, but the intensity is weaker. Convective activity in August exhibits a single peak in the afternoon with the most significant diurnal variation, which shows a typical afternoon thermal convection type.

The ability to differentiate species is not adequate for modern forage breeding programs. The measurement of persistence is currently a bottleneck in the breeding system that limits the throughput of cultivars to the marketplace and prevents it from being selected as a trait. The use of hyperspectral data obtained through remote sensing offers the potential to reduce guesswork by identifying the distribution of pasture species, but only if such data alone can distinguish the subtle differences within species, i.e., cultivars. The implementation of this technology faces many challenges due to the spectral and temporal variability of species. To understand the spectral variability between and within species groups, differentiation using hyperspectral data from monoculture plots of turf species was utilized. Spectral data were collected over a year using an ASD FieldSpec® and canopy pasture probe (CAPP). The plots consisted of monocultures of various species, and cultivars (a total of 10 plots). Linear discriminant analysis (LDA) was conducted on the full spectrum and reduced band data. This technique successfully differentiated the species with high accuracy (>98%). We demonstrate the potential of hyperspectral data and analysis techniques to accurately separate differences down to cultivar level. We also show that diurnal variation is measurable in the spectra but does not preclude differentiation.

Aerosol acidity is a critical factor affecting atmospheric chemistry. Here, we present a study on annual, monthly, and daily variations in PM2.5 pH in Shanghai during 2010–2020. With the effective control of SO2 emissions, the NO2/SO2 ratio increased from 1.26 in 2010 to 5.07 in 2020 and the NO3−/SO42− ratio increased from 0.68 to 1.49. Aerosol pH decreased from 3.27 in 2010 to 2.93 in 2020, regardless of great achievement in reducing industrial SO2 and NOx emissions. These findings suggest that aerosol acidity might not be significantly reduced in response to the control of SO2 and NOx emissions. The monthly variation in pH values exhibited a V-shape trend, mainly attributable to aerosol compositions and temperature. Atmospheric NH3 plays the decisive role in buffering particle acidity, whereas Ca2+ and K+ are important acidity buffers, and the distinct pH decline during 2010–2016 was associated with the reduction of Ca2+ and K+ while both temperature and SO42− were important drivers in winter. Sensitivity tests show that pH increases with the increasing relative humidity in summer while it is not sensitive to relative humidity in winter due to proportional increases in Hair+ and aerosol liquid water content (ALWC). Our results suggest that reducing NOx emissions in Shanghai will not significantly affect PM2.5 acidity in winter.

The spatial–temporal variations of fine particulate matter (PM2.5) in Akure, a city in southwestern Nigeria, are examined based on multi-year continuous observations using low-cost PM2.5 sensors at six different sites. The average annual concentration of PM2.5 across these sites was measured at 41.0 µg/m3, which surpassed both the Nigerian national air quality standard and the World Health Organization air quality guideline level. PM2.5 levels were significantly higher during the dry season (November–March), often exceeding hazardous levels (over 350 µg/m3), than during the wet season. The analyses of trends in air mass trajectories and satellite data on fire occurrences imply that the transport of dust and accumulation of PM2.5 originating from local/regional open burning activities played crucial roles in increased PM2.5 concentrations during the dry season. Further, site-to-site variations in the PM2.5 levels were observed, with relatively high concentrations at less urbanized sites, likely due to high local emissions from solid fuel combustion, waste burning, and unpaved road dust. Diurnal patterns showed morning and evening peaks at less urbanized sites, accounting for an estimated 51–77% of local emissions. These results highlight the importance of local emission sources in driving spatial–temporal PM2.5 variations within the city and the need for targeted mitigation strategies to address the significant air pollution challenges in Akure and similar regional cities in West Africa.

Airborne microplastics (MPs) are receiving increasing attention due to their ubiquitous nature and the potential human health consequences resulting from inhalation. The limited data for airborne MP concentrations vary widely among studies (∼4 orders of magnitude), but comparisons are tenuous due to the inconsistent collection and detection/enumeration methodologies among studies. Herein, we used uniform methodologies to obtain comparable airborne MP concentration data to assess MP exposure intensity in five Chinese megacities. Airborne MP concentrations in northern cities (358 ± 132 items/m3) were higher than those in southeast cities (230 ± 94 items/m3) but of a similar order of magnitude, unlike previous studies. The majority (94.7%) of MPs found in air samples were smaller than 100 μm, and the main shape of airborne MPs was fragments (88.2%). Polyethylene, polyester, and polystyrene were the dominant polymers comprising airborne MPs. No consistent relationships were detected between airborne MP concentration and typical socioeconomic indices, and the spatial and diurnal patterns for airborne MPs were different from various components of air quality indices (PM2.5, PM10, etc.). These findings reflect the contrasting source/generation dynamics between airborne MPs and other airborne pollutants. Maximum annual exposure of humans to airborne MPs was estimated in the range of 1-2 million/year in these megacities, highlighting the need for additional research examining the human health risks from the inhalation of airborne MPs.

Beijing, Tianjin, Hebei and neighbouring areas (34°-43°N, 113°-123°E) are located at the north edge of the East Asian summer monsoon, and they are also the main heavy-rain areas in northern China. The hourly precipitation data of 87 national meteorological stations from 1966 to 2021 are used for the analysis of spatial distribution and interannual variations, while the data of 298 stations from 1980 to 2021 are used to statistically analyze the diurnal variations and interannual variations of light precipitation (0.1-20 mm·h-1) and short-time heavy precipitation (no less than 20 mm·h-1) for the warm season (May-September) over the region. The results show that the annual average light precipitation and frequency in Beijing, Tianjin, Hebei and neighbouring areas during the warm season are much higher than those of short-time heavy precipitation. However, there is an area in the west of the Bohai Sea Region (37°-41°N, 115°-119.5°E) with high short-time heavy rainfall intensity but weak rainfall amount and frequency, which means the convective characteristics of short-time precipitation over this area are more extreme and significant. The interannual variations of two kinds of precipitation amount, frequency, and intensity in Beijing, Tianjin, Hebei and neighbouring areas excluding the west of Bohai Sea Region both present an overall growing trend in the warm season, in which the increasing trend of short-time heavy precipitation is more obvious, but the trend in the west of the Bohai Sea Region is not obvious. The diurnal variation amplitudes of light precipitation amount and frequency in Beijing, Tianjin, Hebei and neighbouring areas excluding the west of the Bohai Sea Region are significantly weaker than those of short-time heavy precipitation, but the peak durations are significantly longer. Compared to Beijing, Tianjin, Hebei and neighbouring areas excluding the west of the Bohai Sea Region, two types of precipitation in the west of the Bohai Sea Region from July to September are more frequent and the rainfall peak durations are longer. The interannual variations of precipitation in different periods of the whole day show that the light precipitation in two regions both decrease in the afternoon, while the short-time heavy precipitation has weakened significantly in the afternoon since 2005, but increased significantly from midnight to early morning.

Abstract Background Significant diurnal fluctuation of optical coherence tomography (OCT)-based macular fluid occurs in patients with several macular conditions including diabetic macular edema (DME) and cystoid macular edema due to retinal venous occlusion (RVO). OCT imaging and analysis of macular fluid status plays a central role in clinical management of exudative age-related macular degeneration (eAMD), however diurnal variation of eAMD OCT findings has not yet been formally studied. Herein, we investigate whether clinically meaningful fluctuation of OCT-based macular fluid occurs in patients with eAMD. Methods Prospective observational study. Patients with eAMD and intra- and/or sub-retinal fluid on early AM OCT were enrolled to receive two consecutive OCT scans at least four hours later. Retinal layers were manually segmented on all OCT rasters and AM-to-PM and PM-to-PM image pairs were analyzed for total retinal and neurosensory retinal volume changes within the central 1 and 3 mm ETDRS subfields. Finally, two masked retinal specialists analyzed all OCT image pairs for qualitative differences that may impact clinical management. Results 21 patients with eAMD and fluid on OCT were recruited between January 2020 and November 2021. There was no mean difference between AM and PM central 3 mm total retinal volume (p = 0.56), central 3 mm neurosensory retinal volume (p = 0.25), central 1 mm total retinal mean thickness (p = 0.96), or central 1 mm neurosensory retinal mean thickness (p = 0.63), nor were any differences identified in PM-to-PM control comparisons. Qualitative analysis by two masked experts identified no clinically significant differences between any AM-to-PM OCT image pairs. Conclusions No significant diurnal variation in OCT-based macular fluid or thickness was identified in patients with eAMD, either quantitatively or qualitatively.

Enshi is a foggy area in Hubei Province with complex terrain and large spatial difference in fog. However, the meteorological stations in this area are sparse, making it difficult to study the spatio-temporal distribution characteristics of fog. This paper uses the land surface data from CLDAS (China Meteorological Administration Land Data Assimilation System) and the Enshi station to analyze the spatiotemporal characteristics of fogging potential index in the Enshi area. The results are show below. (1) According to the hourly data of Enshi station in the past 30 years, a high relative humidity over 90% and a small difference (≤2.0 ℃) between actual temperature and dew point temperature (T-Td) are favorable for fogging. (2) The diurnal variation of fogging potential index based on the CLDAS data and the observations in the Enshi area are consistent and correlated. Therefore, the CLDAS data can be used to study the characteristics of fogging potential in the Enshi area. (3) There is significant spatio-temporal variation of relative humidity in the Enshi region. The relative humidity in the south region is higher than that in the north, and also varies with the altitude. In terms of time, it increases at night. The relative humidity varies greatly from day to night in the low mountains area, but varies little in the middle mountains area. (4) The spatial distribution and diurnal variation of fogging potential index are basically consistent with that of relative humidity. The highest frequency is found in the southern and central Enshi area between 800 m and 1200 m, and the lowest frequency is found in the northern Three Gorges dry and hot valley, namely the lee side of Wushan Mountains. In addition, the highest frequency occurs in winter.

In-depth understanding of the diurnal variation of soil respiration and its influencing factors at different depths under different land use patterns in desertified open-pit mines is crucial to assessing the carbon cycle of ecosystems in ecologically fragile open-pit mines. Taking the Hongshaquan open-pit mine as the research object, the EGM-5 portable infrared gas observation system was used to monitor and obtain the diurnal respiration rate of soil at different depths under different land use types and obtain related influencing factors. Also, the variation law and characteristics, as well as their main influencing factors of soil respiration under different land use types were got. The results showed that: ① There are significant differences in diurnal soil respiration among the five representative types of land features. The daily average soil respiration rates at 10 and 30 cm depths are ordered as artificial forest > Hongshaquan > reclamation area of dump > tamarisk forest > southern line, at 10 cm depth are 5.72, 0.98, 0.34, 0.08 and −0.08 μmol/(m2·s), respectively, and at 30 cm depth are 5.14, 2.18, 0.77, 0.40 and −0.05 μmol/(m2·s), respectively. The southern line is carbon sink, and the other four types of land features are carbon sources. ② The diurnal variation of soil respiration rate is obvious. The diurnal variation of soil respiration in different soil layers and Hongshaquan at 10 cm depth in the reclamation area of the dump site shows a “double peak” trend. The diurnal variation of soil respiration at 10 and 30 cm depths in tamarisk forest shows a “multi-peak” trend. ③ On the diurnal scale, the soil respiration rate at 10 cm depth in the dump reclamation area, the artificial forest and Hongshaquan is significantly positively correlated with soil temperature (P < 0.05) and soil water content (P < 0.01). The diurnal respiration of soil in the forest and the southern line is weak, and the daytime soil temperature in the tamarisk forest and the southern line limits soil respiration, while the nighttime and early morning soil temperature promotes soil respiration. Soil temperature and soil water content can better explain the variation of soil respiration rate of 50.5%−97.3% for the five feature types in the mine area, while only 11.3% for 10 cm in the southern line. ④ There are differences in the relationship between soil respiration and soil carbon content in tamarisk forest and southern line, and the relationship between the soil respiration and soil carbon content of the other three types of land features. The tamarisk forest and southern line soil respiration have a significant negative correlation with inorganic carbon (SIC) (r=0.69, P < 0.01), the soil respiration rate is negative due to inorganic processes, and SIC is the key factor of soil carbon sink. However, the soil respiration in dump reclamation area, artificial forest and Hongshaquan all have a strong negative correlation with dissolved active organic carbon (DOC). The soil respiration in southern line and tamarisk forest also has a strong positive correlation with soil organic carbon (SOC). SOC and DOC are important factors of soil carbon sources. To sum up, the soil respiration rates of different types of land features and different depths in the Hongshaquan mining area are significantly different, and the responses of soil respiration to soil temperature and other environmental factors are different at different depths. It is preliminarily clarified that SIC is an important factor for soil carbon sinks, while SOC and DOC are important factors for soil carbon sources. The results can provide basic data for carbon emissions and carbon cycle in the mining area.

The present study to quantify the variations in microclimate under wheat, mustard and chickpea crops was conducted at ICAR-Indian Institute of Farming Systems Research, Modipuram, Meerut (U.P.), India. Air temperature, relative humidity, CO2 concentration below and above the canopies of wheat, mustard and chickpea were recorded at hourly interval from 07:30 to 17:30 hours at different heights (0.5 m, 1.0 m and 2.0 m) from the ground. CO2 probes like GMP-343, (Diffusion aspiration) was used to record data of CO2 concentration and HPM-75 probes was used to capture the observation of air temperature and relative humidity. Results revealed that diurnal air temperature was continuously increasing from morning to afternoon hrs and highest air temperature was recorded at 13:30 hrs (afternoon). Thereafter, air temperature decreased and reached to the lowest at 17:30 hrs irrespective of crops and height from the ground. Analysis of diurnal air temperature variations at different height clearly showed that tall statured crop such as wheat and mustard reached higher air temperature regime early (13.30 hrs) compared to short statured crop like chickpea at 15.30 hrs. Highest relative humidity was observed at 07.30 hrs and lowest relative humidity was recorded either at 13:30 hrs or at 15:30 hrs. As per study maximum CO2 concentration was found at 07:30 hrs morning and minimum at 15:30 hrs. The lowest concentration of CO2 (624 ppm) was recorded from the chickpea field and highest from the mustard field (630 ppm) at the same point of observation during vegetative phase of crops.

Abstract Meteorological conditions and source emissions in grassland areas are quite different from those in urban areas, which significantly impacts the spatiotemporal characteristics of black carbon (BC). To obtain the characteristics of BC in the typical grassland environment in China, continuous observations of BC were carried out in Etuoke Banner, a typical grassland environment in Ordos, from September 8 to December 1, 2022. BC in Etuoke Banner in autumn is 22.4–4667.5 ng m−3, and the average concentration is 456.6 ng m−3, accounting for 2.20% of the mass fraction of PM2.5. BCliquid (BC generated from the combustion of liquid fuels) is the main component of BC (accounting for 79.2%); the average concentration is 361.7 ng m−3. The diurnal variations of BC, BCliquid, and BCsolid (BC generated from the combustion of solid fuels) are bimodal, with peaks at 08:00 and 18:00. The first peak is mainly related to traffic sources, cooking sources, and incomplete combustion of carbon‐containing substances; the second peak may be caused by emissions from residential cooking sources under the influence of meteorological conditions unfavorable to diffusion. The diurnal variation of absorption Ångström exponent (AAE) is unimodal, with the peak at 14:00. With the increase in BC mass concentration, AAE and visibility gradually decreased, wind speed first decreased and then increased, P and RH gradually increased, and the contribution of biomass combustion sources to BC decreased. In contrast, the contribution of traffic sources to BC increased. The evolution characteristics of atmospheric pollutants differed with the increase in BC concentration. The potential sources and affecting areas of BC and PM2.5 are mainly concentrated around Etuoke Banner and can affect the North China Plain after 48 h of transmission.

The partitioning of semi-volatile organic compounds (SVOCs) between gas and particle phases plays a crucial role in their long-range transport and health risk assessment. However, the accurate predicting of the gas/particle (G/P) partitioning quotient (KP') remains a challenge, especially for the light molecular weight (LMW) SVOCs due to their upward deviation from the equilibrium state. Based on the diurnal study of concentrations and KP' values for methylated polycyclic aromatic hydrocarbons (Me-PAHs), it was found that the diurnal variations of methylated naphthalenes (Me-Naps, one type of LMW SVOCs) were different from other Me-PAHs, that KP' values during daytime were higher than that during nighttime, and the regression lines of log KP' versus log KOA (octanol-air partitioning coefficient) for daytime and nighttime were non-overlap. It was found that the higher gaseous degradation of Me-Naps during daytime than that during nighttime should be responsible for their special diurnal variation of KP', which provided a new explanation for the non-equilibrium behavior of KP' of LMW SVOCs. Moreover, the influence of gaseous degradation on the deviation of KP' from the equilibrium state was deeply studied based on a theoretical model considering particulate proportion in emission (0). It was found that the deviation occurred when 0FGR (FGR, degradation flux of gas phase) cannot be ignored when compared with FGP (flux from gas phase to particle phase). It can be concluded that the deviation was not only related to the gaseous degradation rate (kdeg), but also related to 0. Furthermore, an amplification of KP' ranging from 1 to 8.4 times under different 0 (0 to 1) in the temperature range of -50 to 50°C was estimated based on the individual degradation rates of Me-Naps and three LMW PAHs. In summary, it can be concluded that the influence of gaseous degradation should also be considered for the G/P partitioning models of SVOCs, especially for the LMW SVOCs, which provided new insights into the related fields. [ABSTRACT FROM AUTHOR]

Various aspects of tropical cyclones (TCs) fluctuate with the diurnal cycle. TC size is critical to the extent of its damage, but diurnal variations in the growth of the outer region size have largely remained unexplored. This paper examines the diurnal variations in the growth of the radius of gale‐force winds (34 kt; R34) by analyzing best‐track data from 2001 to 2019 for both North Atlantic TCs and global TCs outside of the North Atlantic region. Statistically significant diurnal variations was found for R34 growth, with the maximum 6‐h growth rate occurring at 2100–0300 local solar time (LST) for North Atlantic TCs, and at 0300–0900 LST for global TCs excluding the North Atlantic which experienced rapid intensification (≥30 knots within 24 h). The higher R34 6‐h growth rates during the night were linked to a larger extent of very deep convective clouds with infrared brightness temperatures <208 K during this time. [ABSTRACT FROM AUTHOR]

Tennis match performance is often evaluated by a player's internal (heart rate) and external (match analytics) outcomes. Numerous factors could influence these outcomes, including the time of day, which may be advantageous or not depending on a player's chronotype. This study aimed to determine the influence time of day, chronotype and sleep–wake behaviour (SWB) had on internal and external outcomes of tennis matches. Twelve state-level male tennis players, with a mean age of 28 ± 7, stature of 183 ± 7 and body mass of 86.6 ± 17.4 wore an actigraph device and completed a sleep diary for the study duration. Based on rankings, players were paired against the same opponent and completed three tennis matches at 8:00 am, 2:00 pm and 8:00 pm, separated by a minimum of 48 h. Fatigue and chronotype, measured by the Fatigue Severity Scale, Morningness Eveningness Questionnaire and midsleep time, were assessed before matches; motivation, measured by the Intrinsic Motivation Inventory, was assessed after matches. During matches, players wore global positioning systems and heart rate monitors; the match analytics and players' rate of perceived exertion were recorded. Increased unforced errors and decreased winners and forced errors were observed in the evening matches. Decreased total distance and rate of perceived exertion during the second set were found for the evening compared to morning and afternoon matches. Chronotype and sleep–wake behaviour had trivial to weak associations with internal and external outcomes. These results indicate that players and coaches should consider the match times when training for future tournaments. [ABSTRACT FROM AUTHOR]

To investigate the diurnal variation in phytoplankton biomass and its regulating factors during the diurnal cycle, we conducted in situ observations in June 2018 at three buoy stations, including Douwei Buoy Station, Minjiang Estuary Buoy Station, and Huangqi Buoy Station on the western side of the Taiwan Strait. The calibration of buoy sensor data, including temperature, salinity, dissolved oxygen, pH, chlorophyll, and phycoerythrin, was conducted simultaneously. In addition, water sampling was conducted to measure chlorophyll a and phycoerythrin concentrations at hourly time intervals. The results showed that the 24 h cumulative chlorophyll a concentration order for the buoys was Minjiang Estuary (10.280 μg/L) > Huangqi (7.411 μg/L) > Douwei (4.124 μg/L). The Minjiang Estuary had a lower nighttime biomass proportion than Douwei and Huangqi. The diurnal variation in phytoplankton was jointly regulated by water masses, tides, and light. There were three response patterns, including the "light trumps tidal influences" pattern at Douwei, the "Low-tide, High-biomass" pattern at Minjiang Estuary, and the "High-tide, High-biomass" pattern at Huangqi. The prediction of algal blooms and hypoxia using buoy monitoring needs to be based on seasonal water mass background and tidal influence. [ABSTRACT FROM AUTHOR]

In this study, we assessed the effects of different harvest times (9 a.m., 1 p.m., and 5 p.m.) and hydrodistillation times (60, 90, and 120 min) on the yield, chemical composition, and antioxidant activity of the spearmint (Mentha spicata L.) essential oil (EO) sourced from the Amazon region. EO yield was ≥1.55% and was not significantly influenced (p ≥ 0.05) by the different harvest times and hydrodistillation times. Thirty-one different organic compounds were identified, of which menthol (91.56–95.68%), menthone (0.6–2.72%), and isomenthone (0.55–1.46%) were the major constituents. The highest menthol content in the EO was obtained from samples collected at 9 a.m., with a hydrodistillation time of 60–90 min, compared to other harvest and hydrodistillation times. This suggests that exposure to sun and light, which is greater at harvest times of 1 p.m. and 5 p.m., decreased the menthol content and altered the chemical composition of Mentha EO. Furthermore, the sample harvested at 9 a.m. and hydrodistilled for 60 min showed the highest antioxidant activity (61.67 equivalent mg of Trolox per g of EO), indicating that antioxidant activity is strongly affected by light exposure and the contact duration of the sample with boiling water during hydrodistillation. [ABSTRACT FROM AUTHOR]

Mixing layer height (MLH) is an important meteorological parameter for air quality since it significantly affects ground-level pollution in the atmosphere. This study examined the properties of the MLH on diurnal and seasonal timescales over a 3-year period (2020–2022) using high temporal resolution measurements from eight Vaisala CL31 ceilometers situated around Slovakia. Hourly averaged MLH data was retrieved from the BL-View software using merged method. The highest daily maxima for the MLH occurred mostly in summer and spring, while the lowest values occurred predominantly during winter and autumn. The average MLH daily maximum in summer was 2229 m, and just 859 m in winter. During summer, the spatial distribution of the MLH daily maxima was more uniform compared to winter, when the air masses within the individual valleys did not mix well. Correlations between ground-level pollutant concentrations and hourly mean/daily mean MLH were analyzed. The highest correlation, R≈0.6, was found for O3. For PM10, PM2.5, and NOx, the anticorrelations with MLH were found with maximum in winter (R ≈ − 0.3 for hourly data and R ≈ − 0.5 for daily mean data) but no relation in summer. Lastly, the ceilometer MLH was compared to the radiosonde retrieved MLH for various cloud covers. Our analysis is based on an extensive set of empirical data, which can improve the accuracy and effectiveness of meteorological and atmospheric chemistry models. The findings can support air pollution forecasting and warning systems, providing valuable insights for policymakers and researchers. [ABSTRACT FROM AUTHOR]

Background: To investigate the changes in macular cystic schisis (MCS) and sensitivity during the day in X-linked retinoschisis (XLRS) patients. Methods: Treatment-naïve patients with genetically verified XLRS underwent best-correlated visual acuity (BCVA) testing with ETDRS charts, spectral domain optical coherence tomography, and microperimetry (MP) twice a day, at 9 a.m. and 4 p.m., to measure changes in central retinal thickness (CRT), macular volume (MV), average threshold (AT), and fixation stability parameters (P1 and P2). Results: At baseline, the BCVA of the 14 eyes of 8 patients amounted 0.73 (± 0.23) LogMAR. Between timepoints, the BCVA increased in 3.21 letters (p =.021), the AV improved in 1.84 dB (p =.03, 9.73%), the CRT decreased in 24.43 µm (p =.007, − 4.05%), and the MV dropped in 0.27 µm3 (p =.016, − 2.68%). P1 and P2 did not variate. The collapse of the MCS led to the reduction of macula thickness. CRT at baseline correlated with the decrease of CRT (Spearman's ρ: − 0.83 [p =.001]). Age and change of BCVA, CRT, and AV did not correlate among one another. Eyes with disrupted ellipsoid zone showed a more prominent change in CRT (p =.050). Photoreceptor outer segment length and integrity of the external limiting membrane and cone outer segment tips were not associated with BCVA, AT, or CRT variation. Conclusion: Eyes of treatment-naïve XLRS patients show diurnal macular thickness and function changes. Eyes with pronounced macular thickness show a greater reduction of the MCS. These results should be taken into consideration in upcoming clinical trials in XLRS. Trial registration number: Institutional Review Board of the Hamburg Medical Chamber (Ethik-Kommission der Ärztekammer Hamburg): 2020–10,328. [ABSTRACT FROM AUTHOR]

In order to explore the characteristics and sources of carbonaceous species at different locations in Beijing in autumn and winter, online continuous observations of organic carbon (OC), element carbon (EC), PM2.5, O3, CO, NOx and meteorological factors were carried out simultaneously at urban and roadside sites in September and December 2020. The results showed that air quality was good during the study period, the p(OC), p(EC), p(PM2.5) were (5.66±3.54), (1.59±1.31), (32.9±25.1) μg/m³ at roadside site, respectively, which were 32%, 70% and 33% higher than urban site. PM2.5 pollution was heavier at roadside, vehicles may be a major contributor to the carbonaceous species especially EC, In autumn, there was no significant difference in OC concentration between two sites, and EC was 47% higher at roadside site, ω (total carbonaceous matter (TCM=1.4xOC+EC)) in PM2.5 were 29% and 25% at urban and roadside sites. In winter, OC and EC at roadside site were 54% and 83% higher than those at urban site, ω (TCM) were 27% and 31% at urban and roadside sites. PM2.5 and gaseous pollutants were higher in winter than in autumn, and higher at roadside than at urban site, except O3. Under weak wind conditions, the concentration of carbonaceous species at urban and roadside sites were 1.3~1.6 and 2.0~3.8 times of that under non-weak wind conditions. Therefore, it is crucial to take emission reduction measures under weak wind conditions to improve air quality. There were little difference between OC/EC ratios under weak wind conditions at two sites, OC/EC were 2.56 and 3.35 in autumn and winter. Local emission was the main influence factor under weak wind conditions, OC/EC were 2.99 and 1.86 at urban and roadside sites. The p (secondary organic carbon (SOC)) and SOC/OC, calculated using the minimum OC/EC (OC/EC)min in different meteorological conditions, were 1.99 μg/m³ and 47% at urban site, 3.13 μg/m³ and 55% at roadside site. In autumn SOC concentration was lower but accounted for a higher proportion of OC. In terms of diurnal variation, OC and EC kept low concentrations and fluctuated slightly throughout the day under non-weak wind conditions. Under weak wind conditions, OC at the two sites presented a bimodal distribution, with peaks around 12:00 and 19:00. Due to the atmospheric boundary layer changes and pollution emissions, the noon peak was not obvious and the concentration was prominent in the mid-night in winter. EC curve at urban site showed bimodal peaks in the morning and evening rush-hour with low concentration, EC showed a "V" shaped distribution and concentration continued to be high around midnight. In autumn, the correlation between PM2.5 and carbon components was weak, and roadside vehicles contributed more to carbon particles. The correlation was strong in winter, so attention should be paid to combustion emission transmission in the south and southeast of the region. [ABSTRACT FROM AUTHOR]

Context: Single ACTH measurements have limited ability to distinguish patients with Cushing's disease (CD) from those in remission or with other conditions. Objective: To investigate the changes in ACTH levels before and after transsphenoidal surgery (TSS) to identify trends that could confirm remission from CD and help establish ACTH cutoffs for targeted clinical trials in CD. Design: Retrospective analysis of CD patients who underwent TSS from 2005 to -2019. Setting: Referral center. Patients: CD patients (n = 253) with ACTH measurements before and after TSS. Interventions: TSS for CD. Main Outcome Measures: Remission after TSS. Results: Remission was observed in 223 patients after TSS. Those in remission had higher ACTH variability at AM (P = .02) and PM (P < .001) time points compared to nonremission. The nonremission group had a significantly narrower diurnal range compared to the remission group (P = <.0001). A decrease in plasma ACTH of =50% from mean preoperative levels predicted CD remission after TSS, especially when using PM values. The absolute plasma ACTH concentration and ratio of preoperative to postoperative values were significantly associated with nonremission after multivariable logistic regression (adj P < .001 and .001, respectively). Conclusions: Our findings suggest that ACTH variability is suppressed in CD, and remission from CD is associated with the restoration of this variability. Furthermore, a decrease in plasma ACTH by 50% or more may serve as a predictor of remission post-TSS. These insights could guide clinicians in developing rational outcome measures for interventions targeting CD adenomas. [ABSTRACT FROM AUTHOR]

Urban heat islands have garnered significant attention due to their potential impact on human life. Previous studies on urban heat islands have focused on characterizing temporal and spatial variations over longer periods of time. In this study, we investigated the urban heat island (UHI) in Birmingham from September 2013 to August 2014 using higher temporal resolution SEVIRI satellite surface temperature data along with data from the Birmingham Urban Climate Laboratory (BUCL) meteorological station and the UK Meteorological Office meteorological station. Our aim was to characterize the diurnal variations in the surface urban heat island intensity (SUHII) and canopy urban heat island intensity (CUHII) and to explore their relationship under the influence of three factors (day/nighttime, season, and wind speed) using regression analysis. Our findings reveal that SUHII and CUHII exhibit relatively stable patterns at night but vary significantly during the day with opposite diurnal trends. In addition, SUHII and CUHII were more variable in spring and summer but less variable in winter. During the nighttime, SUHII represents CUHII with high confidence, especially during spring and summer, but less so during the cold season. In addition, SUHII represents CUHII with greater confidence under low-wind conditions. This study deepens our understanding of the diurnal dynamics of urban heat islands and the influence of atmospheric conditions on the relationship between surface and canopy heat islands in urban areas. The results of this study can be used for heat island studies in cities that lack high-precision observation networks and to guide sustainable urban development. [ABSTRACT FROM AUTHOR]

This study investigates the diurnal migration of the low‐level jet (LLJ) over the Bay of Bengal in the summer monsoon, which remains understudied despite the well‐documented diurnal offshore propagation of rainfall worldwide. The southwesterly LLJ exhibits maximum strength during the night and morning. The LLJ undergoes a substantial eastward migration of approximately 600 km from the eastern offshore of India at midnight to the center of the Bay of Bengal by afternoon. A linear land‐sea breeze model is effective in capturing the diurnal migration with similar speed and phase. Including background wind offshore extends the migration, rather than confining it to the coast. This migration is driven by inertia‐gravity waves arising from the diurnal land‐sea thermal contrast and is influenced by the westerly upstream wind from the Indian subcontinent. Our results have important implications for understanding diurnal monsoon circulations and their associated precipitation. Plain Language Summary: The low‐level jet (LLJ) in the summer monsoon plays a crucial role in affecting nocturnal downstream precipitation in South Asia. Previous studies have primarily concentrated on changes in the jet's strength during the day, neglecting its varying location. The present study addresses this gap by providing a comprehensive examination of the previously neglected aspect of the diurnal offshore migration of the LLJ over the Bay of Bengal. The diurnal migration is driven by the difference in temperature between the land and sea and is also aided by upstream wind, in a manner similar to the diurnal offshore propagation of rainfall. Overall, this study offers a more complete understanding of the LLJ' behaviors in the summer monsoon, which can help explain how it affects rainfall in the region. Key Points: The monsoon low‐level jet migrates eastward from the eastern offshore of India at midnight to the center of the Bay of Bengal by afternoonThe offshore diurnal migration is driven by inertia‐gravity waves resulting from the diurnal thermal contrast between land and seaThe westerly upstream wind from the Indian subcontinent extends the offshore migration, rather than confining it to the coast [ABSTRACT FROM AUTHOR]

Sprint and jump performances represent performance-determining parameters in individual and team sports. Fluctuations in performance depending on the daytime raise the question of the best time to train and compete. Given the scarce research on females, this study aimed to analyze the influence of daytime on sprint and jump performances and to investigate whether the performance difference is related to the chronotype. Thus, 23 female sports students completed a questionnaire to assess their chronotype followed by performing two 30 m sprints, 5 Repeated Jump Tests (5RJT), and countermovement jumps (CMJ) in the morning (7:00–9:00 h) and evening (17:00–19:00 h). Time after 5 m, 10 m, and 30 m during the sprints, reactive strength index (RSI) during the 5RJTs, and jump height during the CMJs were examined. The performance during the 30 m sprint (t(22) = 5.28, p < 0.01 moderate effect size: 0.50) and the two jump tests (5RJT: t(22) = 8.27, p < 0.01 large effect size: 0.95; CMJ: t(22) = 5.46, p < 0.01 moderate effect size: 0.79) were significantly better in the evening than in the morning. There was no significant correlation between chronotype and the time-of-day effect. The results should be considered when planning training and competition. [ABSTRACT FROM AUTHOR]

The diurnal variation characteristics of precipitation in summer (June–August) during the period of 2015–2019 over the Northern Slope of the Tianshan Mountains (NSTM) was analyzed using hourly simulated data from Nanjing University's real-time forecasting system (WRF_NJU) with 4 km resolution, Automatic Weather Station (AWS) data, and the ERA5-Land data through using methods such as the Rotated Empirical Orthogonal Function (REOF) and Coefficient of Variation (CV). The results show that the diurnal variation pattern of the precipitation over the NSTM simulated by WRF_NJU aligns closely with that of the observational AWS data, and it captured spatial distribution, peak values, and the times of precipitation reasonably well. The hourly precipitation amount (PA), precipitation frequency (PF), and precipitation intensity (PI) all show characteristics of being greater in the afternoon to nighttime than from early morning to noon, and the diurnal variations of precipitation in this region are significantly influenced by altitude. The PA, PF, and PI peak over the southern edge of the Junggar Basin (JB) below 1000 m occurred at around 2200 Local Solar Time (LST). In contrast, peak PA over the mountainous regions above 3000 m occurred at around 1500 LST. Further analysis with REOF and CV indicated that the difference in diurnal variations of precipitation between the mountainous regions and the JB is most pronounced likely due to the topographical influences. The peak PA over the mountainous regions mainly occurred at around 1500 LST, while that of the JB occurred at around 0100 LST. High CV regions for PI are predominantly found over the area near the central JB and the middle Tianshan mountains, whereas high CV regions for the PF are located in the central and northern parts of Urumqi and Changji. In addition, different land surface categories exhibit distinct patterns of diurnal precipitation variation, i.e., the forests, grasslands, and water bodies exhibit their peak PA in the period from early morning to noon, while the impervious surfaces, croplands, and barren lands exhibit their peak PA in the period from afternoon to nighttime. [ABSTRACT FROM AUTHOR]