Average Nighttime Research Articles

Ozone trends over the United States at different times of day

Abstract. In the United States, the decline of summertime daytime peak ozone in the last 20 years has been clearly connected to reductions in anthropogenic emissions. However, questions remain about how and through what mechanisms ozone at other times of day have changed over recent decades. Here we analyze the interannual variability and trends of ozone at different hours of day, using observations from about 1000 US sites during 1990–2014. We find a clear diurnal cycle both in the magnitude of ozone trends and in the relative importance of climate variability versus anthropogenic emissions to ozone changes. Interannual climate variability has mainly been associated with the detrended fluctuation in the US annual daytime ozone over 1990–2014, with a much smaller effect on the nighttime ozone. Reductions in anthropogenic emissions of nitrogen oxides have led to substantial growth in the US annual average nighttime ozone due to reduced ozone titration, while the summertime daytime ozone has declined. Environmental policymaking might consider further improvements to reduce ozone levels at night and other non-peak hours.

Chemical characterization and sources of PM2.5 at 12-hr resolution in Guiyang, China.

The increasing emission of primary and gaseous precursors of secondarily formed atmospheric particulate matter due to continuing industrial development and urbanization are leading to an increased public awareness of environmental issues and human health risks in China. As part of a pilot study, 12-hr integrated fine fraction particulate matter (PM2.5) filter samples were collected to chemically characterize and investigate the sources of ambient particulate matter in Guiyang City, Guizhou Province, southwestern China. Results showed that the 12-hr integrated PM2.5 concentrations exhibited a daytime average of 51 ± 22μg·m-3 (mean ± standard deviation) with a range of 17-128μg·m-3 and a nighttime average of 55 ± 32μg·m-33 with a range of 4-186 μg·m-3. The 24-hr integrated PM2.5 concentrations varied from 15 to 157 μg·m-3, with a mean value of 53 ± 25 μg·m-3, which exceeded the 24-hr PM2.5 standard of 35μg·m-3 set by USEPA, but was below the standard of 75μg·m-3, set by China Ministry of Environmental Protection. Energy-dispersive X-ray fluorescence spectrometry (XRF) was applied to determine PM2.5 chemical element concentrations. The order of concentrations of heavy metals in PM2.5 were iron (Fe) > zinc (Zn) > manganese (Mn) > lead (Pb) > arsenic (As) > chromium (Cr). The total concentration of 18 chemical elements was 13 ± 2 μg·m-3, accounting for 25% in PM2.5, which is comparable to other major cities in China, but much higher than cities outside of China.

Urban heat island intensity and spatial variability by synoptic weather type in the northeast U.S.

Understanding regional air temperature (Ta) variability and urban heat island (UHI) magnitude has posed challenges given the minimal observational stations in urban areas. This study uses a dense network to evaluate the degree to which synoptic weather influences the UHI intensity and fine scale Ta variability on days of extreme heat. We examine daytime and nighttime temperatures in four large northeastern cities (urban-suburban-rural) using a dataset with relatively high spatiotemporal resolutions (100–200 stations per area, 5min or 60min intervals) for May–Sept, 2006–2013. Results show stronger UHI intensity and enhanced Ta variability under hot, dry weather types, with the most intense UHIs overnight in dry conditions. Absolute Ta magnitudes within both urban and rural areas remain heightened under moist weather type conditions. New York City presents the highest average nighttime UHI intensity (3.51°C). Minimal, and at times negative, UHIs are often present in the daytime, appearing on 38% and 28% of days in New York City and Boston, respectively. An exploratory analysis demonstrates a significant ability to predict average Ta at each station using common environmental predictors. Findings emphasize the importance in distinguishing between absolute maximum Ta versus UHI intensity by weather type for communication and translation of heat mitigation practices and health protection by public health and urban planning agencies.

Shorter sleep duration is associated with higher energy intake and an increase in BMI z-score in young children predisposed to overweight.

Inadequate sleep has been shown to be a contributor to obesity in both children and adults. Less evidence is available for toddlers and among those with higher obesity risk. The objective of this study was to examine the relationship between sleep patterns and body weight development in a group of young obesity-predisposed children, and to assess whether intakes of energy or macronutrients mediate this relationship. Participants included 368 Danish children aged 2-6 years from the Healthy Start Study, a 1.3 year randomised controlled intervention trial. Sleep habits were measured using a 7-day sleep diary. Multivariate linear regression with adjustment for confounders was used to assess the association of sleep duration and sleep variability with 1.3 year changes (Δ) in body mass index (BMI) z-score from baseline to follow-up. The average nighttime sleep duration was 10.7 h (range 8.8-12.5 h). After controlling for potential confounders, a significant inverse association between nighttime sleep duration and ΔBMI z-score (β=-0.090, P=0.046) was observed. This relationship was mediated by energy intake, with all macronutrients contributing to this mediation effect. No associations were found for sleep variability and ΔBMI z-score but baseline intake of added sugars and sugary beverages were positively associated with sleep variability. Shorter sleep duration, mediated by energy intake in early in life, seems a risk factor for weight gain among young obesity-predisposed children.

PP.05.29] CIRCADIAN RHYTHM OF BLOOD PRESSURE AND TARGET ORGAN DAMAGE IN PATIENTS WITH RESISTANT HYPERTENSION

Objective: To investigate characteristics of circadian blood pressure rhythm, frequency and character of hypertensive damage of heart, kidney and carotid arteries in patients (pts.) with true resistant arterial hypertension (RAH). Design and method: 43 essential hypertensive pts. were included in the study. According to office and ambulatory BP measurement after 2 month of treatment with fixed dose combination perindopril/indapamide/amlodipine 10/2.5/10 they were divided into two groups: the 1-st - 22 pts. with confirmed RAH and the 2-d - 21 pts. with controlled arterial hypertension (AH). Before starting of treatment pts. were underwent ambulatory blood pressure monitoring (ABPM),, ultrasonography of heart and carotid arteries, laboratory tests (serum creatinine and 24-hour albuminuria). Results: Two groups were comparable in age (51.4 ± 2.6 vs. 54.2 ± 1.9 y, p = 0.63), body mass index (32.2 ± 0.9 vs. 33.4 ± 1.1 kg/m2, p = 0.35) and office systolic (174.4 ± 4.1 vs. 175.5 ± 4.5 mmHg, p = 0.78) and diastolic (97.3 ± 4.4 vs. 102.4 ± 2.4 mmHg) BP. But pts. with RAH had higher level of ambulatory systolic BP (SBP), than patients of comparing group: average diurnal SBP 169.2 ± 2.8 vs. 159.0 ± 2.8 mmHg (p = 0.03), average daytime SBP 173.5 ± 2.9 vs. 164.6 ± 2.4 mmHg (p = 0.04) and average nighttime SBP 161.9 ± 3.4 vs. 148.6 ± 4.2 mmHg (p = 0.02). Ambulatory diastolic BP doesn’t differ between two groups: average diurnal DBP 96.2 ± 3.3 vs. 89.5 ± 2.3 mmHg (p = 0.27), average daytime DBP 100.4 ± 3.5 vs. 94.0 ± 2.4 mmHg (p = 0.24) and average nighttime DBP 88.5 ± 3.2 vs. 80.6 ± 2.4 mmHg (p = 0.19). Diurnal systolic and diastolic BP index was significantly lower in RAH patients – 6.7 ± 1.2 vs. 10.1 ± 1.4% and 11.6 ± 1.1 vs. 15.0 ± 1.3% respectively. Disturbance of circadian BP rhythm was detected in72.7% RAH pts. in compare with43.0% pts. with controlled AH. LVH (concentric type in all cases) was diagnosed at 100% RAH pts. and in 90% pts. in comparing group (concentric type in 61.5% of cases). Frequency of carotid atherosclerosis (68.8 vs. 46.6%) and intima-media thickness (1.49 ± 0.07 vs. 1.17 ± 0.06 mm, p = 0.003) were significantly higher at RAH than at controlled AH pts. Glomerular filtration rate was equal in comparing groups when albuminuria was greater in RAH pts.-18.4 ± 3.3 vs. 15.2 ± 2.1 mg/l (p = 0.03). Conclusions: RAH pts. characterizes by higher level of ambulatory SBP and more frequent disturbances of BP circadian rhythm in comparing with controlled AH pts. These peculiarities of ambulatory BP is accompanied with concentric LVH, atherosclerotic and hypertensive damage of carotid arteries and signs of kidney injury.

Status of noise pollution in urban area of Dharan Sub- Metropolitan City and Inaruwa Municipality of Sunsari District, Nepal

The environmental noise level measurement in Dharan and Inaruwa cities of eastern Nepal were conducted and compared with the ambient noise standards provided by Government of Nepal. The noise pollution assessment was performed in autumn and winter seasons by the indicator average day time sound pressure level (Ld, during 7.00 to 22.00 hrs) and average night time sound pressure level (Ln, during 22.00 to 7.00 hrs). The Ld and Ln values at the commercial, silence and residential zones of Dharan were 78 to 82 and 72 to 73, 65 to 73 and 60 to 70, 65 to 76 and 62 to 64 dB(A) in autumn and 78 to 79 and 72 to 76, 64 to 71 and 58 to 68, 63 to 74 and 60 to 62 dB(A) in winter, respectively whereas for Inaruwa, measurement were 75 to 77 and 73 to 75, 59 and 57, 67 and 60 dB(A) in autumn and 66 to 70 and 63 to 68, 55 and 53, 65 and 58 dB(A) in winter, respectively. The results showed that noise levels exceeded the standard value at most of the sites.

1017 CLINICAL OUTCOMES OF CONTINUOUS POSITIVE AIRWAY PRESSURE IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA AND NON-DIPPING BLOOD PRESSURE: A PROSPECTIVE COHORT STUDY

Nondipping blood pressure (BP) and obstructive sleep apnea (OSA) both carry an increased risk of cardiovascular events and mortality. We aim to investigate the effects of 6 months of continuous positive airway pressure (CPAP) treatment on blood pressure (BP) and urine albumin/creatinine ratio (ACR) in OSA patients with nondipping patterns. We prospectively enrolled adult patients with severe OSA (AHI>30) from November 2010 to December 2015 for ambulatory 24-hr BP study. Baseline 24hr BP was recorded, urine was collected for ACR and peripheral venous blood samples were collected for the analysis of CBC-DC, creatinine, lipid profile, and high sensitivity CRP (hsCRP). After CPAP use, we measured 24-hr BP, hsCRP and ACR at 3 and 6 months separately. Statistical analyses (paired T test, generalized estimating equation) were performed by SAS. A total of 77 patients were enrolled. At baseline, 42(54.5%) of patients were dippers and 35(45.5%) were non-dippers (a decrease of less than 10% in the average nighttime blood pressure compared with the average daytime blood pressure). In non-dippers, the mean AHI was 70.0 (SD, 22.7), baseline 24-hr mean BP was 125.0(SD, 17.1) mmHg (systolic blood pressure (SBP): 140.1(SD, 19.7) mmHg, diastolic blood pressure (DBP): 95.0(SD, 13.8)mmHg).CPAP treatment decreased SBP by 1.59 mmHg (95% confidence interval (CI):-9.2 to 3.6; p=0.287), and diastolic blood pressure by 3.13 mmHg (95%CI:-7.5 to 0.7; p=0.062). After 6 months of CPAP treatment, 20(57.1%) of non-dippers displayed dipping BP pattern and 15(42.9%) were refractory non-dippers (average day-night BP decrease 14.3 ± 3.6%, 3.0 ± 5.1%; P<0.001). Non-dippers had a reduction in ACR (-14.0 ± 42.7 mg/L) (p=0.061) and those who displayed dipping pattern after CPAP had the most significant reduction in ACR (-7.0 ± 10.25 mg/L) (p=0.010). HsCRP level decreased significantly in non-dippers who had dipping pattern after CPAP (-1.13 ± 3.73 mg/L) when compared with refractory non-dippers (3.05 ± 6.08 mg/L) (p=0.024). In severe OSA patients with nondipping BP, CPAP treatment for 6 months improved BP pattern. In those who displayed dipper pattern after CPAP, the decrease of ACR was significant. This effect of non-dippers converting to dippers was associated with greater decrease in hsCRP. None

Influence of human population movements on urban climate of Beijing during the Chinese New Year holiday

The population movements for the Chinese New Year (CNY) celebrations, known as the world’s largest yearly migration of human beings, have grown rapidly in the past several decades. The massive population outflows from urban areas largely reduce anthropogenic heat release and modify some other processes, and may thus have noticeable impacts on urban climate of large cities in China. Here, we use Beijing as an example to present observational evidence for such impacts over the period of 1990–2014. Our results show a significant cooling trend of up to 0.55 °C per decade, particularly at the nighttime during the CNY holiday relative to the background period. The average nighttime cooling effect during 2005–2014 reaches 0.94 °C relative to the 1990s, significant at the 99% confidence level. The further analysis supports that the cooling during the CNY holiday is attributable primarily to the population outflow of Beijing. These findings illustrate the importance of population movements in influencing urban climate despite certain limitations. As the world is becoming more mobile and increasingly urban, more efforts are called for to understand the role of human mobility at various spatial and temporal scales.

Twenty-Four-Hour Blood Pressure Monitoring to Predict and Assess Impact of Renal Denervation: The DENERHTN Study (Renal Denervation for Hypertension).

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01570777.

Decoding white coat hypertension.

There is arguably no less understood or more intriguing problem in hypertension that the “white coat” condition, the standard concept of which is significantly blood pressure reading obtained by medical personnel of authoritative standing than that obtained by more junior and less authoritative personnel and by the patients themselves. Using hospital-initiated ambulatory blood pressure monitoring, the while effect manifests as initial and ending pressure elevations, and, in treated patients, a low daytime profile. The effect is essentially systolic. Pure diastolic white coat hypertension appears to be exceedingly rare. On the basis of the studies, we believe that the white coat phenomenon is a common, periodic, neuro-endocrine reflex conditioned by anticipation of having the blood pressure taken and the fear of what this measurement may indicate concerning future illness. It does not change with time, or with prolonged association with the physician, particularly with advancing years, it may be superimposed upon essential hypertension, and in patients receiving hypertensive medication, blunting of the nighttime dip, which occurs in about half the patients, may be a compensatory mechanisms, rather than an indication of cardiovascular risk. Rather than the blunted dip, the morning surge or the widened pulse pressure, cardiovascular risk appears to be related to elevation of the average night time pressure.

Nocturnal Hypertension and Altered Night-Day BP Profile and Atherosclerosis in Renal Transplant Patients.

The clinical relevance of ambulatory blood pressure monitoring (ABPM) for risk stratification in renal transplant patients still remains poorly defined. We investigated the association between clinic and ABPM with an established biomarker of atherosclerosis (intima-media thickness [IMT] by echo-color Doppler) in a large, inclusive survey (n = 172) in renal transplant patients at a single institution. Forty-two patients (24%) were classified as hypertensive by ABPM criteria and 29 (17%) by clinic blood pressure (BP) criteria. Average daytime and nighttime BP was 126 ± 12/78 ± 9 mm Hg and 123 ± 13/74 ± 10 mm Hg, respectively. Forty-five patients (26%) were classified as hypertensive by the daytime criterion (>135/85 mm Hg) and a much higher proportion (n = 119, 69%) by the nighttime criterion (>120/70 mm Hg). Sixty-two patients (36%) had a night-day ratio of 1 or greater, indicating clear-cut nondipping. The average nighttime systolic BP (r = 0.24, P = 0.001) and the night-day systolic BP ratio (r = 0.23, P = 0.002) were directly related to IMT, and these associations were much more robust than the 24-hour systolic BP-IMT relationship (r = 0.16, P = 0.04). Average daytime BP and clinic B were unrelated to IMT. In a multiple regression analysis adjusting for confounders, the night-day systolic BP ratio maintained an independent association with IMT (β = 0.14, P = 0.04). In renal transplant patients, the prevalence of nocturnal hypertension by far exceeds the prevalence of hypertension as assessed by clinic, daytime, and 24-hour ABPM. Nighttime systolic BP and the night-day ratio but no other BP metrics are independently associated with IMT. Blood pressure during nighttime may provide unique information for the assessment of cardiovascular risk attributable to BP burden in renal transplant patients.

Evolution of severe sleep-wake cycle disturbances following traumatic brain injury: a case study in both acute and subacute phases post-injury

BackgroundSleep-wake disturbances are frequently reported following traumatic brain injury (TBI), but they remain poorly documented in the acute stage of injury. Little is known about their origin and evolution.Case presentationThis study presents the case of a patient in the acute phase of a severe TBI. The patient was injured at work when falling 12 m into a mine and was hospitalized in the regular wards of a level I trauma centre. From days 31 to 45 post-injury, once he had reached a level of medical stability and continuous analgosedation had been ceased, his sleep-wake cycle was monitored using actigraphy. Results showed significant sleep-wake disturbances and severe sleep deprivation. Indeed, the patient had an average nighttime sleep efficiency of 32.7 ± 15.4 %, and only an average of 4.8 ± 1.3 h of sleep per 24-h period. After hospital discharge to the rehabilitation centre, where he remained for 5 days, the patient was readmitted to the same neurological unit for paranoid delusions. During his second hospital stay, actigraphy recordings resumed from days 69 to 75 post-injury. A major improvement in his sleep-wake cycle was observed during this second stay, with an average nighttime sleep efficiency of 96.3 ± 0.9 % and an average of 14.1 ± 0.9 h of sleep per 24-h period.ConclusionThis study is the first to extensively document sleep-wake disturbances in both the acute and subacute phases of severe TBI. Results show that prolonged sleep deprivation can be observed after TBI, and suggest that the hospital environment only partially contributes to sleep-wake disturbances. Continuous actigraphic monitoring may prove to be a useful clinical tool in the monitoring of patients hospitalized after severe TBI in order to detect severe sleep deprivation requiring intervention. The direct impact of sleep-wake disturbances on physiological and cognitive recovery is not well understood within this population, but is worth investigating and improving.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-016-0709-x) contains supplementary material, which is available to authorized users.

Infant sleep hygiene counseling (sleep trial): protocol of a randomized controlled trial.

BackgroundSleep problems in childhood have been found to be associated with memory and learning impairments, irritability, difficulties in mood modulation, attention and behavioral problems, hyperactivity and impulsivity. Short sleep duration has been found to be associated with overweight and obesity in childhood. This paper describes the protocol of a behavioral intervention planned to promote healthier sleep in infants.MethodsThe study is a 1:1 parallel group single-blinded randomized controlled trial enrolling a total of 552 infants at 3 months of age. The main eligibility criterion is maternal report of the infant’s sleep lasting on average less than 15 h per 24 h (daytime and nighttime sleep). Following block randomization, trained fieldworkers conduct home visits of the intervention group mothers and provide standardized advice on general practices that promote infant’s self-regulated sleep. A booklet with the intervention content to aid the mother in implementing the intervention was developed and is given to the mothers in the intervention arm. In the two days following the home visit the intervention mothers receive daily telephone calls for intervention reinforcement and at day 3 the fieldworkers conduct a reinforcement visit to support mothers’ compliance with the intervention. The main outcome assessed is the between group difference in average nighttime self-regulated sleep duration (the maximum amount of time the child stays asleep or awake without awakening the parents), at ages 6, 12 and 24 months, evaluated by means of actigraphy, activity diary records and questionnaires. The secondary outcomes are conditional linear growth between age 3–12 and 12–24 months and neurocognitive development at ages 12 and 24 months.DiscussionThe negative impact of inadequate and insufficient sleep on children’s physical and mental health are unquestionable, as well as its impact on cognitive function, academic performance and behavior, all of these being factors to which children in low- and middle-income countries are at higher risk. Behavioral interventions targeting mothers and young children that can be delivered inexpensively and not requiring specialized training can help prevent future issues by reducing the risk to which these children are exposed.Trial registrationClinicalTrial.gov NCT02788630 registered on 14 June 2016 (retrospectively registered).

OP.4C.03] 24H BLOOD PRESSURE MONITORING TO PREDICT AND ASSESS IMPACT OF RENAL DENERVATION

Objective: The Renal Denervation for Hypertension (DENERHTN) trial showed that renal denervation (RD) with the Symplicity™ catheter added to a standardized stepped-care antihypertensive treatment (SSAHT) significantly reduced daytime ambulatory SBP by ∼6 mmHg more than the SSAHT alone after 6 months in patients with resistant hypertension. The aim of this analysis is to report in details the ABPM results, and to look for predictors of the BP response to RD. Design and method: 24 h ABPM were performed at baseline and 6 months. For each recording, we calculated the average and standard deviation (SD) of 24 h, daytime and nighttime SBP, DBP and HR, and the smoothness index (SI). Analyses were performed on the per-protocol population to compare the RD group (RDG) to the control group (CG) and responders (daytime SBP reduction > = 20 mmHg) to non-responders. Results: 44/ 53 patients of the RDG and 53/53 of the CG were included. The average number of measurements for each ABPM was 73. The significantly greater ambulatory SBP reduction in the RDG was homogeneous over 24 h with a higher SI (1.4 ± 1.2) than in the CG (0.9 ± 0.6; P = 0.02). SD of 24 h, daytime and nighttime SBP/DBP and HR were not significantly influenced by RD. In a stepwise discriminant analysis, baseline average nighttime SBP, nighttime SDSBP and treatment group were significant predictors of the daytime ambulatory SBP response at 6 months. The first two remained significantly associated to responders (P = 0.005) in the RDG but not in CG. The ROC curves to predict responders in the RDG had an area under the curve of 0.65 (95%CI: 0.488–0.815, P = 0.08) for nighttime SBP and 0.72 (95%CI: 0.566- 0.874, P = 0.01) for nighttime SDSBP. The cut-offs offering best sensitivity+specificity to predict responders were136 mmHg for nighttime SBP and 12 mmHg for nighttime SDSBP. Together, these cut-offs allow adequate classification of 70% of responder patients. Conclusions: This analysis of ABPM data in DENER-HTN confirms the efficacy of RD in lowering BP in patients with resistant hypertension, with an homogenous effect along the 24 h. Baseline nighttime SBP and SDSBP appear as good candidates to predict responders to RD.

The regular nocturnal course of temperature in the midlatitude mesopause region according to hydroxyl airglow measurements

Using ground-based spectral measurements in the near-infrared range at the Zvenigorod scientific station of the Institute of Atmospheric Physics (56° N, 37° E) for 2000–2013, we obtained average nighttime changes in rotational and vibrational temperatures of hydroxyl with its emission layer localized at mesopause heights. The rotational temperature reflects the kinetic temperature of the emission layer of the atmosphere. The analysis made it possible to determine the characteristics of the first three harmonics of diurnal temperature dynamics in the mesopause region both with and without altitudinal oscillations of the OH emission layer. In both cases, the second and third harmonics are statistically significant: their amplitudes are ∼1 K and the phases of their first maxima are near 0300 and 0130 local solar time.

The global surface temperatures of the Moon as measured by the Diviner Lunar Radiometer Experiment

The Diviner Lunar Radiometer Experiment onboard the Lunar Reconnaissance Orbiter (LRO) has been acquiring solar reflectance and mid-infrared radiance measurements nearly continuously since July of 2009. Diviner is providing the most comprehensive view of how regoliths on airless bodies store and exchange thermal energy with the space environment. Approximately a quarter trillion calibrated radiance measurements of the Moon, acquired over 5.5 years by Diviner, have been compiled into a 0.5° resolution global dataset with a 0.25h local time resolution. Maps generated with this dataset provide a global perspective of the surface energy balance of the Moon and reveal the complex and extreme nature of the lunar surface thermal environment. Our achievable map resolution, both spatially and temporally, will continue to improve with further data acquisition.Daytime maximum temperatures are sensitive to the albedo of the surface and are ∼387–397K at the equator, dropping to ∼95K just before sunrise, though anomalously warm areas characterized by high rock abundances can be > 50K warmer than the zonal average nighttime temperatures. An asymmetry is observed between the morning and afternoon temperatures due to the thermal inertia of the lunar regolith with the dusk terminator ∼30K warmer than the dawn terminator at the equator. An increase in albedo with incidence angle is required to explain the observed decrease in temperatures with latitude. At incidence angles exceeding ∼40°, topography and surface roughness influence temperatures resulting in increasing scatter in temperatures and anisothermality between Diviner channels.Nighttime temperatures are sensitive to the thermophysical properties of the regolith. High thermal inertia (TI) materials such as large rocks, remain warmer during the long lunar night and result in anomalously warm nighttime temperatures and anisothermality in the Diviner channels. Anomalous maximum and minimum temperatures are highlighted by subtracting the zonal mean temperatures from maps. Terrains can be characterized as low or high reflectance and low or high TI. Low maximum temperatures result from high reflectance surfaces while low minimum temperatures from low-TI material. Conversely, high maximum temperatures result from dark surface, and high minimum temperatures from high-TI materials.Impact craters are found to modify regolith properties over large distances. The thermal signature of Tycho is asymmetric, consistent with an oblique impact coming from the west. Some prominent crater rays are visible in the thermal data and require material with a higher thermal inertial than nominal regolith. The influence of the formation of the Orientale basin on the regolith properties is observable over a substantial portion of the western hemisphere despite its age (∼3.8Gyr), and may have contributed to mixing of highland and mare material on the southwest margin of Oceanus Procellarum where the gradient in radiative properties at the mare-highland contact is broad (∼200km).

PM2.5 particulates and metallic elements (Ni, Cu, Zn, Cd and Pb) study in a mixed area of summer season in Shalu, Taiwan

PM2.5 has become an important environmental issue in Taiwan during the past few years. Moreover, electricity increased significantly during the summertime and TTPP generated by coal burning base is the main electricity provider in central Taiwan. Therefore, summer season has become the main research target in this study. The ambient air concentrations of particulate matter PM2.5 and PM10 collected by using VAPS at a mixed characteristic sampling site were studied in central Taiwan. The results indicated that the average daytime PM2.5 and PM10 particulate concentrations were occurred in May and they were 44.75 and 57.77µg/m3 in this study. The results also indicated that the average nighttime PM2.5 and PM10 particulate concentrations were occurred in June and they were 38.19 and 45.79µg/m3 in this study. The average PM2.5/PM10 ratios were 0.7 for daytime, nighttime and 24-h sampling periods in the summer for this study. This value was ranked as the lowest ratios when compared to the other seasons in previous study. Noteworthy, the results further indicated that the metallic element Pb has the mean highest concentrations for 24-h, daytime and nighttime sampling periods when compared to those of the other metallic elements (Ni, Cu, Zn and Cd). The average mean highest metallic Pb concentrations in PM10 were 110.7, 203.0 and 207.2ng/m3 for 24-h, daytime and nighttime sampling periods in this study. And there were 59.53, 105.2 and 106.6ng/m3 for Pb in PM2.5 for 24-h, daytime and nighttime sampling periods, respectively. Moreover, the results further indicated that mean metallic element Pb concentrations on PM2.5 and PM10 were all higher than those of the other elements for 24h, day and nighttime.

Surface thermal analysis of North Brabant cities and neighbourhoods during heat waves

The urban heat island effect is often associated with large metropolises. However, in the Netherlands even small cities will be affected by the phenomenon in the future (Hove et al., 2011), due to the dispersed or mosaic urbanisation patterns in particularly the southern part of the country: the province of North Brabant. This study analyses the average night time land surface temperature (LST) of 21 North-Brabant urban areas through 22 satellite images retrieved by Modis 11A1 during the 2006 heat wave and uses Landsat 5 Thematic Mapper to map albedo and normalized difference temperature index (NDVI) values. Albedo, NDVI and imperviousness are found to play the most relevant role in the increase of night-time LST. The surface cover cluster analysis of these three parameters reveals that the 12 “urban living environment” categories used in the region of North Brabant can actually be reduced to 7 categories, which simplifies the design guidelines to improve the surface thermal behaviour of the different neighbourhoods thus reducing the Urban Heat Island (UHI) effect in existing medium size cities and future developments adjacent to those cities.

Observational Evidence for Involvement of Nitrate Radicals in Nighttime Oxidation of Mercury.

In the atmosphere, reactive forms of mercury species can be produced by oxidation of the dominant gaseous elemental mercury (GEM). The oxidation of GEM is an important driver for deposition, but oxidation pathways currently are poorly constrained and likely differ among regions. In this study, continuous measurements of atmospheric nitrate radical (NO3) concentrations and mercury speciation (i.e., elemental and reactive, oxidized forms) were performed during a six week period in the urban air shed of Jerusalem, Israel during summer 2012, to investigate the potential nighttime contribution of nitrate radicals to oxidized mercury formation. Average nighttime concentrations of reactive gaseous mercury (RGM) were almost equivalent to daytime levels (25 pg m(-3) and 27 pg m(-3) respectively), in contrast to early morning and evening RGM levels which dropped to low levels (9 and 13 pg m(-3)). During daytime, the presence of RGM was increased when solar radiation exceeded 200 W m(-2), suggesting a photochemical process for daytime RGM formation. Ozone concentrations were largely unrelated to daytime RGM. Nighttime RGM concentrations were relatively high (with a maximum of 97 pg m(-3)) compared to nighttime levels in other urban regions. A strong correlation was observed between nighttime RGM concentrations and nitrate radical concentration (R(2) averaging 0.47), while correlations to other variables were weak (e.g., RH; R(2) = 0.35) or absent (e.g., ozone, wind speed and direction, pollution tracers such as CO or SO2). Detailed analyses suggest that advection processes or tropospheric influences were unlikely to explain the strong nighttime correlations between NO3 and RGM, although these processes may contribute to these relationships. Our observations suggest that NO3 radicals may play a role in RGM formation, possibly due to a direct chemical involvement in GEM oxidation. Since physical data, however, suggest that NO3 unlikely initiates GEM oxidation, NO3 may play a secondary role in GEM oxidation through the addition to an unstable Hg(I) radical species.

Abstract 12241: Exploring the Interaction Between Nighttime Heart Rate and Heart Rate Variability on Future Cardiovascular Event

Introduction: High nighttime heart rate or heart rate variability assessed by ambulatory blood pressure monitoring (ABPM) has been reported to be risk for cardiovascular events. However, it is not clear whether these indices provide synergic risk for cardiovascular events. Hypothesis: The aim of this study is to explore the interaction between nighttime heart rate and heart rate variability on future cardiovascular event. Methods: We studied 1418 patients (average age 64.6±11.6 years, male 47.9%) from J-HOP study who were performed ABPM. We divided average nighttime heart rate (NHR) and nighttime heart rate variability (NHRV) defined as standard deviation of nighttime heart rate into decile groups, and defined the top decile group (NHR 70bpm, NHRV 9.7bpm) as abnormal group, respectively. The average follow-up period was 5.0 years and the incidence of cardiovascular event was 56 events. Results: Kaplan-Meier curve showed that the incidence of cardiovascular event with abnormal NHR and NHRV was higher than those without (Figure A and B). When we divided the patients into 4 groups according to those with or without abnormal NHR and with or without abnormal NHRV, the incidence of cardiovascular event for the group with both abnormal NHR and NHRV was the highest among 4 groups (Figure C). After adjustment for age, sex, body mass index, smoking, alcohol, past history of cardiovascular disease, diabetes, dyslipidemia and 24hr systolic blood pressure, abnormal NHR and NHRV, the presence of abnormal HHR and NHRV has a synergic risk for cardiovascular event (Odds ratio, 7.27; 95% confidence interval, 1.53 to 34.60, P&lt;0.013). Conclusions: The presence of nighttime higher heart rate and heart rate variability obtained every 30 minutes by ABPM has a synergic risk for cardiovascular event.