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Diurnal variation

Mark Brink, Beat Schäffer, Reto Pieren, Jean Marc Wunderli
This article presents empirically derived conversion rules between the environmental noise exposure metrics Leq24h, LDay, LEvening, LNight, Ldn, and Lden for the noise sources road, rail and air traffic. It caters to researchers that need to estimate the value of one (unknown) noise metric from the value of another (known) metric, e.g. in the scope of epidemiological meta-analyses or systematic reviews, when results from different studies are pooled and need to be related to one common exposure metric. Conversion terms are derived using two empirical methods a) based on analyzing the diurnal variation of traffic, and b) by analyzing differences between calculated noise exposure metrics...
October 9, 2017: International Journal of Hygiene and Environmental Health
Miguel Cervantes, Nely Ibarra, Nydia Vásquez, Francisco Reyes, Ernesto Avelar, Salvador Espinoza, Adriana Morales
In areas where the ambient temperature (AT) is above the thermo neutral (TN) zone of pigs, significant changes within a 24-h period occur, differently affecting the availability of amino acids (AA) within the same day. An experiment was conducted to analyze the serum concentrations (SC) of free AA in pigs exposed to diurnal variations in AT. Six pigs (27.1 ±1.3kg body weight) implanted with a thermometer to register the body temperature (BT) at 15-min intervals were used. Blood samples were collected on the last 3 d of the 14-d study, at 0700h (lowest AT), 1200h (mild HS), and 1600h (severe HS)...
October 2017: Journal of Thermal Biology
Rahim Sharafkhani, Narges Khanjani, Bahram Bakhtiari, Yunes Jahani, Rasool Entezar Mahdi
Diurnal Temperature Range (DTR) is a meteorological index which represents temperature variation within a day. This study assesses the impact of high and low values of DTR on mortality. Distributed Lag Non-linear Models combined with a quasi-Poisson regression model was used to assess the impact of DTR on cause, age and gender specific mortality, controlled for potential confounders such as long-term trend of daily mortality, day of week effect, holidays, mean temperature, humidity, wind speed and air pollutants...
October 2017: Journal of Thermal Biology
Jae-Sung Lim, Hyung-Min Kwon, Seong-Eun Kim, Juneyoung Lee, Young-Seok Lee, Byung-Woo Yoon
BACKGROUND AND PURPOSE: Many studies have evaluated the association between weather and stroke, with variable conclusions. Herein we determined the relationships between daily meteorological parameters and acute stroke incidence in South Korea. METHODS: Patients with acute stroke (2,894) were identified by standard sampling of a nationwide insurance claims database from January to December 2011. We used multiple Poisson regression analyses of stroke incidence and meteorological parameters (mean temperature, diurnal temperature change, temperature differences over the preceding 24 hours, atmospheric pressure, humidity, wind speed, and physiologically equivalent temperature) to calculate the relative risk of stroke incidence associated with meteorological parameters...
September 2017: Journal of Stroke
I Smetanová, G Steinitz, K Holý
Long-term radon monitoring was performed in two boreholes, at a depth of 13 m in the 40 m deep V-2 borehole (August 2003-September 2005), and at 3 m depth in the 10 m deep V-3 borehole (August 2003-April 2008). Diurnal, multi-day and annual variations in radon time-series were observed. Daily average of radon activity in V-2 borehole was significantly higher and ranged from 6.5 to 383.7 kBq/m3, while in V-3 borehole only between 1.2 and 139.4 kBq/m3. The seasonal pattern was more pronounced in V-3 time series, with the maximum occurring from October to March...
September 19, 2017: Radiation Protection Dosimetry
Allison E Wolfel, Samantha L Pederson, Allison M Cleymaet, Ann M Hess, Kate S Freeman
OBJECTIVE: To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR(®) Scheimpflug imaging (Pentacam), Optovue(®) iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. ANIMALS STUDIED: Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. PROCEDURES: Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order...
October 15, 2017: Veterinary Ophthalmology
Xingdong Yao, Hongli Zhou, Qian Zhu, Chunhong Li, Huijun Zhang, Jun-Jiang Wu, Futi Xie
In maize-soybean intercropping system, soybean plants will be affected by the wide light-fluctuation, which resulted from the shading by maize plants, as the shading of maize the light is not enough for soybean in the early morning and late afternoon, but at noon, the light is strong as the maize shading disappeared. The objective of this study is to evaluate the photosynthetic response of soybean leaf to the wide light-fluctuation. The data of diurnal variation of photosynthetic characters showed that the photosynthetic rate of intercropped soybean was weaker than that of monocropped soybean...
2017: Frontiers in Plant Science
Yu Sun Kang, Dong-Yoon Yoo, In Hyuk Chung, Eun-Gyong Yoo
PURPOSE: Pubertal gonadotropin secretion shows circadian pattern and the luteinizing hormone (LH) levels tend to rise in later stages of puberty in girls. We studied the usefulness of basal LH in the evaluation of central precocious puberty with emphasis on the influence of sampling time. METHODS: Medical records of 334 girls that underwent gonadotropin-releasing hormone stimulation test (GnRHST) were reviewed. Auxological and laboratory data were compared between those with early morning (EM, before 10 AM) and late morning/afternoon (LM/A, after 10 AM) basal samples...
September 2017: Annals of Pediatric Endocrinology & Metabolism
Shuqin Jiang, Xingnan Ye, Ruyu Wang, Ye Tao, Zhen Ma, Xin Yang, Jianmin Chen
Measurements of particle size distribution and size-resolved particle volatility were conducted using a volatility tandem differential mobility analyzers (V-TDMA) in the urban area of Shanghai during wintertime in January 2014. The nonvolatile mode particles with VSF exceeding 0.85 were always externally mixed with more-volatile mode particles. The average VSF ranged from 0.58 to 0.65 for 100-400nm particles, increasing with the increase of particle size. On average, the nonvolatile mode contributed 15-20% of number fraction for 50-400nm particles...
October 4, 2017: Science of the Total Environment
Ran Lin, Yan Mo, Haihong Zha, Zhipeng Qu, Pancheng Xie, Zheng-Jiang Zhu, Ying Xu, Yue Xiong, Kun-Liang Guan
In addition to responding to environmental entrainment with diurnal variation, metabolism is also tightly controlled by cell-autonomous circadian clock. Extensive studies have revealed key roles of transcription in circadian control. Post-transcriptional regulation for the rhythmic gating of metabolic enzymes remains elusive. Here, we show that arginine biosynthesis and subsequent ureagenesis are collectively regulated by CLOCK (circadian locomotor output cycles kaput) in circadian rhythms. Facilitated by BMAL1 (brain and muscle Arnt-like protein), CLOCK directly acetylates K165 and K176 of argininosuccinate synthase (ASS1) to inactivate ASS1, which catalyzes the rate-limiting step of arginine biosynthesis...
October 5, 2017: Molecular Cell
Mohammad S Haque, Alexandra de Sousa, Cristiano Soares, Katrine H Kjaer, Fernanda Fidalgo, Eva Rosenqvist, Carl-Otto Ottosen
The response of tomato plants (Solanum lycopersicum L. cv. Aromata) to continuous light (CL) in relation to photosynthesis, abscisic acid (ABA) and reactive oxygen species (ROS) was investigated to improve the understanding of the development and/or alleviation of CL-induced leaf injury in constant and diurnal temperature fluctuations with similar daily light integral and daily mean temperature. The plants were grown in three photoperiodic treatments for 15 days; One treatment with a 16/8 h light/dark period and a light/dark temperature of 27/17°C (Control), two CL treatments with 24 h photoperiods, one with a constant temperature of 24°C (CLCT) and the other one with variable temperature of 27/17°C for 16/8 ho, respectively (CLVT)...
2017: Frontiers in Plant Science
Hiroyuki Koyama, Hideomi Ohguchi, Takashi Yagi, Kenro Imaeda
Clinicians sometimes encounter difficulty in diagnosing hypoglycaemia. Here, we present a case report of a 53-year-old woman with recurrent nocturnal hypoglycaemia. A continuous glucose monitoring system (CGMS) revealed postprandial hyperglycaemia and subsequent hypoglycaemia, and an oral glucose tolerance test showed an impaired glycaemic and delayed hyperinsulinaemic pattern. On the basis of these clinical findings, we diagnosed her unexplained hypoglycaemia as reactive hypoglycaemia. CGMS showed a sharp contrast of diurnal variation in blood glucose levels including hypoglycaemia between before and after treatment with an alpha-glucosidase inhibitor, voglibose...
October 4, 2017: BMJ Case Reports
J Lopez-Minguez, J J Morosoli, J A Madrid, M Garaulet, J R Ordoñana
Siesta is a relevant aspect of sleep due to its posited relationship with health or cognitive function. However, unlike night-time sleep, studies about daytime-sleep determinants and characteristics are scarce, and the genetic/environmental structure of siesta is still unknown. Our aim was to explore the relative contribution of genetic and environmental factors to variation in sleep-wake rhythm, measured by a continuous assessment of temperature-activity-position (TAP), which allows for diurnal sleep analysis...
September 26, 2017: Scientific Reports
Leonard T Nguyen, Joshua D Buse, Leland Baskin, S M Hossein Sadrzadeh, Christopher Naugler
OBJECTIVES: Serum iron is an important clinical test to help identify cases of iron deficiency or overload. Fluctuations caused by diurnal variation and diet are thought to influence test results, which may affect clinical patient management. We examined the impact of these preanalytical factors on iron concentrations in a large community-based cohort. DESIGN AND METHODS: Serum iron concentration, blood collection time, fasting duration, patient age and sex were obtained for community-based clinical testing from the Laboratory Information Service at Calgary Laboratory Services for the period of January 2011 to December 2015...
September 23, 2017: Clinical Biochemistry
Karine Heerah, Mathieu Woillez, Ronan Fablet, François Garren, Stéphane Martin, Hélène De Pontual
BACKGROUND: Movement pattern variations are reflective of behavioural switches, likely associated with different life history traits in response to the animals' abiotic and biotic environment. Detecting these can provide rich information on the underlying processes driving animal movement patterns. However, extracting these signals from movement time series, requires tools that objectively extract, describe and quantify these behaviours. The inference of behavioural modes from movement patterns has been mainly addressed through hidden Markov models...
2017: Movement Ecology
Samuel A Ocko, Hunter King, David Andreen, Paul Bardunias, J Scott Turner, Rupert Soar, L Mahadevan
How termite mounds function to facilitate climate control is still only partially understood. Recent experimental evidence in the mounds of a single species, the south Asian termite Odontotermes obesus, suggests that the daily oscillations of radiant heating associated with diurnal insolation patterns drive convective flow within them. How general this mechanism is remains unknown. To probe this, we consider the mounds of the African termite Macrotermes michaelseni, which thrives in a very different environment...
September 15, 2017: Journal of Experimental Biology
Anupma Sharma, Ching Man Wai, Ray Ming, Qingyi Yu
Circadian clock provides fitness advantage by coordinating internal metabolic and physiological processes to external cyclic environments. Core clock components exhibit daily rhythmic changes in gene expression, and the majority of them are transcription factors (TFs) and transcription coregulators (TCs). We annotated 1,398 TFs from 67 TF families and 80 TCs from 20 TC families in pineapple, and analyzed their tissue-specific and diurnal expression patterns. Approximately 42% of TFs and 45% of TCs displayed diel rhythmic expression, including 177 TF/TCs cycling only in the nonphotosynthetic leaf tissue, 247 cycling only in the photosynthetic leaf tissue, and 201 cycling in both...
September 1, 2017: Genome Biology and Evolution
Xin Zhang, Jing Ming, Zhongqin Li, Feiteng Wang, Guoshuai Zhang
Equivalent black carbon (eBC) mass concentrations were measured by an aethalometer (AE-31) in the Nam Co, central Tibet from 2010 to 2014. Different from previous filter-sampling studies (Ming et al., J Environ Sci 22(11):1748-1756, 2010; Zhao et al., Environ Sci Pollut Res 20:5827-5838, 2013), the first high-resolution online eBC measurement conducted in central Tibet is reported here, allowing to discuss the diurnal variations as well as seasonal variabilities of eBC. Average daily eBC concentration was 74 ± 50 ng/m(3), reflecting a global background level...
September 17, 2017: Environmental Science and Pollution Research International
Amit Kumar, Deepak Singh, Krishan Kumar, Braj Bihari Singh, Vinod Kumar Jain
This paper reports the first study which comprises the seasonal, diurnal variability, source characterization, ozone forming potential and risk assessment of volatile organic compounds (VOCs) at three sites (two urban and one rural) in the National Capital Territory of Delhi, India. The study was performed during three seasons of the year 2013-14 and two different categories of VOCs (aromatics and halogenated) have been selected. The study used the sampling and analytical procedures of NIOSH methods. Results showed that the mean concentration of sum of VOCs (∑VOC) is significantly higher at urban sites (110...
September 14, 2017: Science of the Total Environment
Chloe Dafkin, Andrew Green, Benita Olivier, Warrick McKinon, Samantha Kerr
OBJECTIVE: To investigate if diurnal changes in spinal excitability (plantar reflex) occur in restless legs syndrome (RLS) participants compared to healthy matched controls. METHODS: Thirteen RLS participants and 13 healthy control participants' plantar reflex responses were evaluated in the evening (PM) and the morning (AM). Plantar reflex responses were assessed electromyographically, using motion analysis (kinematically) and by subjective nociception (Visual Analogue Scale)...
September 14, 2017: Neuroscience Letters
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