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Diurnal variation

Anthony J Zera, Neetha Nanoth Vellichirammal, Jennifer A Brisson
The functional basis of life history adaptation is a key topic of research in life history evolution. Studies of wing-polymorphism in the cricket Gryllus firmus have played a prominent role in this field. However, prior in-depth investigations of morph specialization have primarily focused on a single hormone, juvenile hormone, and a single aspect of intermediary metabolism, the fatty-acid biosynthetic component of lipid metabolism. Moreover, the role of diurnal variation in life history adaptation in G. firmus has been understudied, as is the case for organisms in general...
April 12, 2018: Journal of Insect Physiology
Zhenchuan Niu, Weijian Zhou, Xue Feng, Tian Feng, Shugang Wu, Peng Cheng, Xuefeng Lu, Hua Du, Xiaohu Xiong, Yunchong Fu
Radiocarbon (14 C) is the most accurate tracer available for quantifying atmospheric CO2 derived from fossil fuel (CO2ff ), but it is expensive and time-consuming to measure. Here, we used common hourly Air Quality Index (AQI) pollutants (AQI, PM2.5 , PM10 , and CO) to indirectly trace diurnal CO2ff variations during certain days at the urban sites in Beijing and Xiamen, China, based on linear relationships between AQI pollutants and CO2ff traced by 14 C ([Formula: see text]) for semimonthly samples obtained in 2014...
April 11, 2018: Environmental Science and Pollution Research International
Martin Bulko, Karol Holý, Monika Müllerová
In practice, information about atmospheric stability is often obtained from discrete stability classes determined from routine meteorological observations. However, changing concentrations of the radioactive gas222 Rn present in the atmosphere are also considered a good indicator of vertical dispersion and atmospheric stability. A complex, in-depth analysis between these different approaches of atmospheric stability assessment has not been performed so far, and was the main motivation behind this study. The study presents atmospheric radon data measured in Bratislava (Slovakia) and stability indexes (SI) calculated according to a modified Turner method during a period of one year...
April 4, 2018: Journal of Environmental Radioactivity
Carlo Vittorio Cannistraci, Tuomo Nieminen, Masahiro Nishi, Levon M Khachigian, Juho Viikilä, Mika Laine, Domenico Cianflone, Attilio Maseri, Khung Keong Yeo, Ravinay Bhindi, Enrico Ammirati
BACKGROUND: ST-elevation acute myocardial infarction (STEMI) represents one of the leading causes of death. The time of STEMI onset has a circadian rhythm with a peak during diurnal hours, and the occurrence of STEMI follows a seasonal pattern with a salient peak of cases in the winter months and a marked reduction of cases in the summer months. Scholars investigated the reason behind the winter peak, suggesting that environmental and climatic factors concur in STEMI pathogenesis, but no studies have investigated whether the circadian rhythm is modified with the seasonal pattern, in particular during the summer reduction in STEMI occurrence...
April 6, 2018: Journal of the American Heart Association
Anne G Hertel, Jon E Swenson, Richard Bischof
There is a growing recognition of the role of individual variation in patterns emerging at higher levels of biological organization. Despite the importance of the temporal configuration of ecological processes and patterns, intraspecific individual variation in diel activity patterns is almost never accounted for in behavioral studies at the population level. We used individual-based monitoring data from 98 GPS-collared brown bears in Scandinavia to estimate diel activity patterns before the fall hunting season...
November 2017: Behavioral Ecology: Official Journal of the International Society for Behavioral Ecology
F Baret, S Madec, K Irfan, J Lopez, A Comar, M Hemmerlé, D Dutartre, S Praud, M H Tixier
Leaf rolling in maize crops is one of the main plant reactions to water stress that can be visually scored in the field. However, leaf-scoring techniques do not meet the high-throughput requirements needed by breeders for efficient phenotyping. Consequently, this study investigated the relationship between leaf-rolling scores and changes in canopy structure that can be determined by high-throughput remote-sensing techniques. Experiments were conducted in 2015 and 2016 on maize genotypes subjected to water stress...
April 2, 2018: Journal of Experimental Botany
Arianna Passarotto, Deseada Parejo, Vincenzo Penteriani, Jesús M Avilés
Owls show an astonishing variation in their degree of colour polymorphism, although the exact mechanisms driving such variation remain controversial. Here we address this fundamental question by considering information on all extant owls and recent advances in comparative methods in the frame of three mutually non-exclusive evolutionary scenarios. In addition, we study for the first time whether the evolution of influential ecological characters facilitated the evolution of colour polymorphism (or vice versa)...
April 3, 2018: Oecologia
Evangelos I Tolis, Giorgos Panaras, John G Bartzis
Air quality and comfort parameters in a naturally ventilated aquatic centre were studied in relation to the outdoor pollution levels. Simultaneous measurements of PM 2.5, as well as of volatile organic compounds, were carried out for the indoor and outdoor environment of the aquatic centre. The chemical analysis of ionic species and trace elements associated with particulate matter was also performed. In addition, automated analyzer for NO2 and O3 was used in order to record the indoor and outdoor levels of these pollutants...
April 2, 2018: Environmental Science and Pollution Research International
Xiaowen Yang, Shuiyuan Cheng, Gang Wang, Ran Xu, Xiaoqi Wang, Hanyu Zhang, Guolei Chen
In this study, the measurement of volatile organic compounds (VOCs) was conducted at Beijing Capital International Airport (ZBAA) and a background reference site in four seasons of 2015. Total concentrations of VOCs were 72.6 ± 9.7, 65.5 ± 8.7, 95.8 ± 11.0, and 79.2 ± 10.8 μg/m3 in winter, spring, summer, and autumn, respectively. The most abundant specie was toluene (10.1%-17.4%), followed by benzene, ethane, isopentane, ethane, acetylene, and n-butane. Seasonal variations of VOCs were analyzed, and it was found that the highest concentration occurring in summer, while the lowest in spring...
March 28, 2018: Environmental Pollution
Shiguo Jia, Sayantan Sarkar, Qi Zhang, Xuemei Wang, Luolin Wu, Weihua Chen, Minjuan Huang, Shengzhen Zhou, Jinpu Zhang, Luan Yuan, Liming Yang
Aerosol acidity has significant implications for atmospheric processing, and high time-resolution measurements can provide critical insights into those processes. This paper reports diurnal variations of aerosol acidity characterized using an open thermodynamic system in Guangzhou, China. Hourly measurements of PM2.5 -associated ionic species and related parameters were carried out during June-September 2013 followed by application of the Extended Aerosol Inorganic Model in open mode to estimate aerosol pH...
March 21, 2018: Chemosphere
Sujin Kim, Seonyeong Lee, Chorong Shin, Jangwoo Lee, Sunmi Kim, Aram Lee, Jeongim Park, Younglim Kho, Rebecca K Moos, Holger M Koch, Sungkyoon Kim, Kyungho Choi
Parabens and triclosan have been widely used in many personal care products and cosmetics. The endocrine disrupting potential of these compounds is of increasing public health concern. The aim of this study is to understand the current exposure profile of these chemicals in last void before bedtime (night-time) and first-morning void (first-morning) urines among a Korean population and to characterize their exposure sources and pathways. A total of 261 people, including infants (0-2 years), toddlers (3-6 years), children (7-12 years), adolescents (13-18 years), and adults (≥19 years), were recruited, and sampled for night-time urine and first-morning urine of the following day...
March 19, 2018: International Journal of Hygiene and Environmental Health
Hui Zhao, Youfei Zheng, Ting Li, Li Wei, Qing Guan
Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95...
March 29, 2018: International Journal of Environmental Research and Public Health
M Böttcher, S Lentini, E R Arens, A Kaiser, D van der Mey, U Thuss, D Kubitza, G Wensing
AIMS: Insufficient erythropoietin (EPO) synthesis is a relevant cause of renal anaemia in patients with chronic kidney disease. Molidustat, a selective hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, increases endogenous EPO levels dose-dependently in preclinical models. We examined the pharmacokinetics, safety, tolerability and the effect on EPO levels after single oral doses of molidustat in healthy male volunteers. METHODS: This was a single centre, randomized, single-blind, placebo-controlled, group-comparison, dose-escalation study...
March 25, 2018: British Journal of Clinical Pharmacology
S Bathiany, M Scheffer, E H van Nes, M S Williamson, T M Lenton
The notion that small changes can have large consequences in the climate or ecosystems has become popular as the concept of tipping points. Typically, tipping points are thought to arise from a loss of stability of an equilibrium when external conditions are slowly varied. However, this appealingly simple view puts us on the wrong foot for understanding a range of abrupt transitions in the climate or ecosystems because complex environmental systems are never in equilibrium. In particular, they are forced by diurnal variations, the seasons, Milankovitch cycles and internal climate oscillations...
March 22, 2018: Scientific Reports
Samuel A Pullinger, Juha Oksa, Liam F Clark, Joe W F Guyatt, Antonia Newlove, Jatin G Burniston, Dominic A Doran, James M Waterhouse, Ben J Edwards
The present study investigated whether increasing morning rectal temperatures (Trec ) to evening levels, or increasing morning and evening Trec to an "optimal" level (38.5°C), resulting in increased muscle temperatures (Tm ), would offset diurnal variation in repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.0 ± 2.3 years, maximal oxygen consumption (V̇O2 max) 60.0 ± 4.4  min-1 , height 1.79 ± 0.06 m, body mass 78...
March 22, 2018: Chronobiology International
Tim Jallow, Patrik Wennberg, Ann-Sofie Forslund
OBJECTIVE: Temporal variations in the occurrence of out-of-hospital cardiac arrest (OHCA) have been shown. Most previous studies have in common that they include individuals whom have received cardiopulmonary resuscitation (CPR) and thus excluding a great number of all the actual cases of OHCA when conducting a study. Therefore the aim of this study was to describe temporal variations of OHCA, regardless of whether CPR was performed or not. DESIGN: All individuals aged 25-74 years in northern Sweden, 1989-2009, who suffered an out-of-hospital cardiac arrest with validated myocardial infarction aetiology (OHCA-V), regardless of whether CPR was performed or not, were included in this study, which resulted in 3357 individuals...
March 22, 2018: Scandinavian Cardiovascular Journal: SCJ
Yin-Chi Cheng, Chin-Chou Huang, Wei-Sheng Chen, De-Feng Huang, Shiow-Ching Shun, Shao-Yu Tsai
BACKGROUND: Sleep disturbances and hypertension are common health issues in patients with systemic lupus erythematosus (SLE). Limited information is available regarding the objective sleep quality and the variation of diurnal blood pressure (BP) in patients with SLE. Moreover, the relationship between sleep patterns and diurnal BP variation in SLE patients is not clear. PURPOSE: To explore the subjective/objective sleep patterns and the diurnal BP variation in women with SLE, to identify the factors associated with diurnal BP variation, and to identify the predictors of this variation...
April 2018: Hu Li za Zhi the Journal of Nursing
Hidenori Otani, Mitsuharu Kaya, Akira Tamaki, Heita Goto, Takayuki Goto, Minayuki Shirato
Active individuals often perform exercises in the heat following heat stress exposure (HSE) regardless of the time-of-day and its variation in body temperature. However, there is no information concerning the diurnal effects of a rise in body temperature after HSE on subsequent exercise performance in a hot environnment. This study therefore investigated the diurnal effects of prior HSE on both sprint and endurance exercise capacity in the heat. Eight male volunteers completed four trials which included sprint and endurance cycling tests at 30 °C and 50% relative humidity...
March 21, 2018: Chronobiology International
Yun Tae Hwang, Lorenzo Rocchi, Paul Hammond, Chris Jd Hardy, Jason D Warren, Basil H Ridha, John Rothwell, Martin N Rossor
Introduction: There is a need for a reliable, noninvasive biomarker for Alzheimer's disease (AD). We assessed whether short-latency afferent inhibition (SAI), a transcranial magnetic stimulation paradigm that assesses cholinergic circuits of the brain, could become such a biomarker. Methods: Nineteen patients with AD underwent four SAI testing sessions. The timing of their usual donepezil dose was altered to create different cholinergic states for each session. This was compared to the SAI results from 20 healthy subjects...
2018: Alzheimer's & Dementia: Translational Research & Clinical Interventions
Samuel A Pullinger, Juha Oksa, Emma L Brocklehurst, Reece P Iveson, Antonia Newlove, Jatin G Burniston, Dominic A Doran, James M Waterhouse, Ben J Edwards
The present study investigated whether increasing morning rectal temperatures (Trec ) to resting.evening levels, or decreasing evening Trec or muscle (Tm ) temperatures to morning values, would influence repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.8 ± 2.6 yr, peak oxygen uptake ([Formula: see text] peak) 60.6 ± 4.6 mL kg min-1 , stature 1.78 ± 0.07 m and body mass 76.0 ± 6.3 kg]. These included a control morning (M, 07:30 h) and evening (E, 17:30 h) session (5-min warm-up), and three further sessions consisting of a warm-up morning trial (ME , on a motorised treadmill) until Trec reached evening levels; and two cool-down evening trials (in 16-17°C water) until Trec (EMrec ) or Tm (EMmuscle ) values reached morning temperatures, respectively...
March 20, 2018: Chronobiology International
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