Daily variation in the patterns and characteristics of adolescent ENDS use.

Author(s):  
Stephen R. Shamblen ◽  
Melissa H. Abadi ◽  
Kirsten T. Thompson ◽  
Sharon Lipperman-Kreda ◽  
Joel W. Grube ◽  
...  
Keyword(s):  
1990 ◽  
Vol 22 (3-4) ◽  
pp. 153-160 ◽  
Author(s):  
T. Okubo ◽  
M. Okada ◽  
A. Murakami ◽  
Y. Inamori

Effects of daily variation of flow on the performance of submerged anaerobic/aerobic biofilm systems were investigated both by laboratory study using synthetic wastewater and by field study using gray water. In laboratory study, concentration of dissolved organic carbon (DOC) in effluent from anaerobic filter fluctuated with daily variation of flow when average hydraulic retention time (HRT) was below 10 h. However, daily mean values of DOC under the varied flow was almost the same as those under constant flow within the same daily mean HRT. Aerobic filter linked to anaerobic filter reduced the concentration of DOC satisfactorily though the concentration in anaerobic filter increased under short HRT. In field study, percent removal of organic carbon by anaerobic filter was considerably smaller (20-30%) than that in laboratory study (90-95%) both at HRT of 20 h though it was improved up to 60-80% by aerobic filter. Effects of peaking factor of flow on the variation of DOC were evaluated by mathematical analysis. It seemed that the peaking factor hardly affected daily mean values of DOC within the same daily mean HRT though maximum values of DOC increased with the increase of peaking factor.


Forecasting ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 377-420
Author(s):  
Julien Chevallier ◽  
Dominique Guégan ◽  
Stéphane Goutte

This paper focuses on forecasting the price of Bitcoin, motivated by its market growth and the recent interest of market participants and academics. We deploy six machine learning algorithms (e.g., Artificial Neural Network, Support Vector Machine, Random Forest, k-Nearest Neighbours, AdaBoost, Ridge regression), without deciding a priori which one is the ‘best’ model. The main contribution is to use these data analytics techniques with great caution in the parameterization, instead of classical parametric modelings (AR), to disentangle the non-stationary behavior of the data. As soon as Bitcoin is also used for diversification in portfolios, we need to investigate its interactions with stocks, bonds, foreign exchange, and commodities. We identify that other cryptocurrencies convey enough information to explain the daily variation of Bitcoin’s spot and futures prices. Forecasting results point to the segmentation of Bitcoin concerning alternative assets. Finally, trading strategies are implemented.


Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 689
Author(s):  
Rudolf Brázdil ◽  
Kateřina Chromá ◽  
Tomáš Púčik ◽  
Zbyněk Černoch ◽  
Petr Dobrovolný ◽  
...  

In the Czech Republic, tornadoes may reach an intensity of F2 and F3 on the Fujita scale, causing “considerable” to “severe” damage. Documentary evidence is sufficient to allow the creation of a chronology of such events, from the earliest recorded occurrence in 1119 CE (Common Era) to 2019, including a total of 108 proven or probable significant tornadoes on 90 separate days. Since only 11 significant tornadoes were documented before 1800, this basic analysis centers around the 1811–2019 period, during which 97 tornadoes were recorded. Their frequency of occurrence was at its highest in the 1921–1930, 1931–1940, and 2001–2010 decades. In terms of annual variations, they took place most frequently in July, June, and August (in order of frequency), while daily variation favored the afternoon and early evening hours. Conservative estimates of human casualties mention 8 fatalities and over 95 people injured. The most frequent types of damage were related to buildings, individual trees, and forests. Tornadoes of F2–F3 intensity were particularly associated with synoptic types characterized by airflow from the western quadrant together with troughs of low pressure extending or advancing over central Europe. Based on parameters calculated from the ERA-5 re-analysis for the period of 1979–2018, most of these tornadoes occurred over a wide range of Convective Available Potential Energy (CAPE) values and moderate-to-strong vertical wind shear. The discussion herein also addresses uncertainties in tornado selection from documentary data, the broader context of Czech significant tornadoes, and the environmental conditions surrounding their origins.


Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1393
Author(s):  
Franciane de Almeida Brehm Goulart ◽  
Gabriela Reichert ◽  
Tais Cristina Felippe ◽  
Alinne Mizukawa ◽  
Jhonatas Antonelli ◽  
...  

In urban areas, wastewater treatment plants (WWTPs) play a major role in the water quality of rivers. The removal efficiency of emerging contaminants by WWTPs is strongly correlated with the type of treatment and the hydraulic retention time (HRT) of the process, which can vary according to the volumetric influent flow of wastewater and occasional peak flows. This paper aims, for the first time, to assess the daily variation of lipid regulators and personal care products in an urban river impacted by domestic effluents. Samples were collected upstream and downstream of a WWTP. The concentrations downstream of the effluent discharge were higher than upstream, but they varied significantly during the day. Concentration peaks upstream of the WWTP were detected at 07:00, 15:00 and 21:00, while downstream of the effluent discharge, concentration peaks occurred between 13:00 and 19:00 and between 21:00 and 23:00. The highest downstream concentrations of triclosan and methylparaben (420 ng L−1 and 460 ng L−1) were 6.8 and 5.4 times higher than the lowest concentrations detected, respectively. These results show that in WWTP-impacted rivers, the time of the sampling has a great influence on the final results and conclusions of a monitoring study.


2021 ◽  
Vol 303 ◽  
pp. 113702
Author(s):  
Stefanny Christie Monteiro Titon ◽  
Braz Titon Junior ◽  
Vania Regina Assis ◽  
Ronyelle Vasconcelos-Teixeira ◽  
Patrício Getúlio Garcia Neto ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriela E. Leghi ◽  
Ching T. Lai ◽  
Ardra Narayanan ◽  
Merryn J. Netting ◽  
Michael Dymock ◽  
...  

AbstractHuman milk (HM) composition is known to be highly variable, both between individuals and across the duration of lactation. It is less clear, however, to what extent fat, lactose and protein concentrations in HM change daily over shorter time periods in mature HM, and no studies have evaluated this to date. The aim of this study was to systematically assess and compare HM macronutrient concentrations in samples collected at different times of day, from left and right breasts and daily across a 3-week period in the same woman. Fifteen lactating women (1.6–4.9 months postpartum) collected daily pre-feed HM samples from both breasts each morning for 21 consecutive days and completed intensive sampling once a week (morning, afternoon and evening samples) during this period. Concentrations of fat, protein and lactose in HM did not differ according to time of day, day of week or breast used for collection. The results of this study suggest that pre-feed samples collected at any point across a 3-week period and from either the left or right breast provide comparable measures of fat, protein and lactose concentrations in mature HM, in pragmatic studies where women are collecting their own HM samples.Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12619000606189).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Quinn M. Biggs ◽  
Robert J. Ursano ◽  
Jing Wang ◽  
Gary H. Wynn ◽  
Rohul Amin ◽  
...  

Abstract Background Sleep disturbances are common in individuals with post traumatic stress disorder (PTSD). However, little is known about how daily variation in sleep characteristics is related to PTSD. This study examined the night-to-night and weekday versus weekend variation in sleep duration, sleep quality, trouble falling asleep, and difficulty staying asleep in individuals with and without PTSD. Methods Participants (N = 157; 80 with PTSD, 77 without PTSD) completed daily self-reports of their nighttime sleep characteristics for 15 consecutive days. Linear mixed models were used to examine the associations between the 7 days of the week and weekday versus weekend variation in sleep characteristics and PTSD. Results Individuals with PTSD reported shorter sleep duration, lower sleep quality, more trouble falling asleep, and more difficulty staying asleep than individuals without PTSD. The pattern of change across the week and between weekdays and weekends was different between those with and without PTSD for sleep quality and trouble falling asleep. Among those with PTSD, sleep duration, sleep quality, and trouble falling asleep differed across the 7 days of the week and showed differences between weekdays and weekends. For those without PTSD, only sleep duration differed across the 7 days of the week and showed differences between weekdays and weekends. Neither group showed 7 days of the week nor weekday versus weekend differences in difficulty staying asleep. Conclusions On average those with PTSD had shorter sleep duration, poorer sleep quality, and greater trouble falling and staying asleep. In particular, the day of week variation in sleep quality and trouble falling asleep specifically distinguishes those with PTSD from those without PTSD. Our findings suggest that clinical care might be improved by assessments of sleep patterns and disturbances across at least a week, including weekdays and weekends. Future studies should explore the mechanisms related to the patterns of sleep disturbance among those with PTSD.


1992 ◽  
Vol 54 (4) ◽  
pp. 669-673 ◽  
Author(s):  
Shin-ichiro KATSUDA ◽  
Hiroshi HOSOMI ◽  
Masashi SHIOMI ◽  
Yoshio WATANABE

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