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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gianluca Botter ◽  
Filippo Vingiani ◽  
Alfonso Senatore ◽  
Carrie Jensen ◽  
Markus Weiler ◽  
...  

AbstractLooking across a landscape, river networks appear deceptively static. However, flowing streams expand and contract following ever-changing hydrological conditions of the surrounding environment. Despite the ecological and biogeochemical value of rivers with discontinuous flow, deciphering the temporary nature of streams and quantifying their extent remains challenging. Using a unique observational dataset spanning diverse geomorphoclimatic settings, we demonstrate the existence of a general hierarchical structuring of river network dynamics. Specifically, temporary stream activation follows a fixed and repeatable sequence, in which the least persistent sections activate only when the most persistent ones are already flowing. This hierarchical phenomenon not only facilitates monitoring activities, but enables the development of a general mathematical framework that elucidates how climate drives temporal variations in the active stream length. As the climate gets drier, the average fraction of the flowing network decreases while its relative variability increases. Our study provides a novel conceptual basis for characterizing temporary streams and quantifying their ecological and biogeochemical impacts.


HortScience ◽  
2021 ◽  
Vol 56 (10) ◽  
pp. 1221-1225
Author(s):  
Reagan W. Hejl ◽  
Benjamin G. Wherley ◽  
Charles H. Fontanier

Landscape irrigation frequency restrictions are commonly imposed by water purveyors and municipalities to curtail domestic water use and to ensure adequate water supplies for growing populations during times of drought. Currently, published data are lacking concerning irrigation frequency requirements necessary for sustaining acceptable levels of turfgrass quality of commonly used warm-season turfgrass species. The objective of this 3-year field study was to determine comparative turfgrass quality of drought-resistant cultivars of four warm-season lawn species in the south–central United States under irrigation frequency regimes of 0, 1, 2, 4, and 8× monthly. Turfgrasses used in the study were based on previously reported drought resistance and included ‘Riley’s Super Sport’ (Celebration®) bermudagrass [Cynodon dactylon (L.) Pers.], ‘Palisades’ zoysiagrass (Zoysia japonica Steud.), ‘Floratam’ st. augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and ‘SeaStar’ seashore paspalum (Paspalum vaginatum Swartz). During each growing season, slightly reduced irrigation volumes and bypassed events resulted from the 8× monthly treatment (34.95 cm, 38.13 cm, and 27.33 cm) compared with the 4× monthly treatment (35.36 cm, 40.84 cm, and 28.70 cm) in years 1, 2, and 3, respectively. For the once weekly treatment, the average fraction of reference evapotranspiration (ETo) supplied by effective rainfall and irrigation during the summer months was 1.22, 0.67, and 0.83 in years 1, 2, and 3, respectively, and was generally adequate to support acceptable turfgrass quality of all warm-season turfgrasses evaluated. Under the less than weekly irrigation frequency, st. augustinegrass and seashore paspalum generally fell to below acceptable quality levels because the average fraction of ETo supplied by effective rainfall and irrigation during the summer months of years 2 and 3 was 0.51, 0.39, and 0.26 for the 2× monthly, 1× monthly, and unirrigated treatments, respectively. Bermudagrass generally outperformed all other species under the most restrictive irrigation frequencies and also did not differ statistically from zoysiagrass. These results show that as irrigation frequency is restricted to less than once per week, species selection becomes an important consideration.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Gongcheng Li ◽  
Shulong Liu ◽  
Zengsheng Wen ◽  
Guolei Liu ◽  
Yu Cui ◽  
...  

Gravity thickening is an important aspect to solve numerous environmental and safety problems that were created by tailings discharging at low solid concentrations. Furthermore, in order to efficiently facilitate the separation of released water and solid sediments, a continuous thickening system with ultrasonic equipment has been used to investigate the thickening performance of copper-mine tailings under different ultrasonic frequencies (16 kHz, 20 kHz, 22 kHz, 25 kHz, and 28 kHz). After freeze-drying treatment, the underflow samples are imaged using the scanning electron microscope (SEM); then, the structure of floc or aggregates in the SEM images is quantifiably analyzed using the software of Image J. Results show that the underflow concentration increases as the ultrasonic frequency increases and decreases afterwards. A linear logarithmic function can explain the relationship between underflow concentration and run time at a certain ultrasonic. The underflow concentration is maximized at 64.47 wt. % when the ultrasonic frequency is 22 kHz. Based on the analysis on the microstructure of underflow samples, the minimum pore average size and pore average fraction are obtained when the ultrasonic frequency is 22 kHz, implying that 22 kHz is the optimum ultrasonic frequency combining the results of the underflow concentration.


Author(s):  
Kristin O'Connor ◽  
Cameron Hurst ◽  
Stacey Llewellyn ◽  
Mark Davies

Objectives The aim of our study was to identify, in mechanically ventilated neonates <30 weeks GA with clinical evidence of bronchopulmonary dysplasia (BPD), factors likely to be predictive of a first course of systemic dexamethasone leading to extubation within 14 days and remaining extubated for at least 7 days. Methods We studied a retrospective cohort of neonates (23+0-29+6 weeks GA), with evidence of BPD, prescribed their first course of systemic dexamethasone to aid in extubation from mechanical ventilation. The data collected only pertained to the first course of dexamethasone for any given neonate, with the primary outcome of interest of successful extubation within 14 days (i.e., extubated within 14 days of starting dexamethasone and remaining extubated for at least seven days). Binary logistic regression was employed. Results A total of 287 neonates were included. Each additional week of GA at birth led to a 1.53 increase in the odds of successful extubation (95% CI 1.122-2.096, p<0.01). Higher average fraction of inspired oxygen (FiO2) requirements in the preceding 24 hours resulted in a 0.94 decrease in the odds of successful extubation (p<0.05) and higher mean airway pressure (MAP) resulted in 0.76 decrease in odds of successful extubation (p<0.01). Conclusions Mechanically ventilated neonates born at <30 week GA, with evidence of BPD requiring dexamethasone to facilitate extubation, had a lower likelihood of successful extubation by day 14 if at the time of commencing steroids they were less mature at birth, had higher MAPs and higher oxygen requirements.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4944
Author(s):  
Hamid M. Ghaithan ◽  
Zeyad. A. Alahmed ◽  
Saif M. H. Qaid ◽  
Abdullah S. Aldwayyan

The effect of halide composition on the structural, electronic, and optical properties of CsPb(Br1−xClx)3 perovskite was investigated in this study. When the chloride (Cl) content of x was increased, the unit cell volume decreased with a linear function. Theoretical X-ray diffraction analyses showed that the peak (at 2θ = 30.4°) shifts to a larger angle (at 2θ = 31.9°) when the average fraction of the incorporated Cl increased. The energy bandgap (Eg) was observed to increase with the increase in Cl concentration. For x = 0.00, 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00, the Eg values calculated using the Perdew–Burke–Ernzerhof potential were between 1.53 and 1.93 eV, while those calculated using the modified Becke−Johnson generalized gradient approximation (mBJ–GGA) potential were between 2.23 and 2.90 eV. The Eg calculated using the mBJ–GGA method best matched the experimental values reported. The effective masses decreased with a concentration increase of Cl to 0.33 and then increased with a further increase in the concentration of Cl. Calculated photoabsorption coefficients show a blue shift of absorption at higher Cl content. The calculations indicate that CsPb(Br1−xClx)3 perovskite could be used in optical and optoelectronic devices by partly replacing bromide with chloride.


2020 ◽  
Vol 4 (24) ◽  
pp. 122-134
Author(s):  
A.M. Mirzakhodzhaev ◽  
◽  
B.A. Mirzakhodzhaev ◽  
D.Kh. Kasimova ◽  
I.B. Radzhabov ◽  
...  

All industrial sericulture is based on the feeding of industrial hybrids. The grain (silkworm eggs) for them is prepared at the breeding enterprises. In the production of high-quality hybrid grain, it is very important to select the most homogeneous fraction from the mixture of breeding cocoons and divide this part by sex with high accuracy, so that the females of one breed are crossed with the males of another and vice versa. It is known that the cocoons of the average fraction (caliber and mass) in the breeding party are the most productive. The purpose of this work was to identify the most informative criteria for selecting the qualitative fraction of breeding cocoons; study the main patterns of variation of cocoons by diameter, quantitative ratios divided into fractions by the caliber of cocoons, and the separability of a mixture of cocoons into components by caliber and weight; based on the revealed regularities, develop some new devices designed for sorting cocoons by caliber and dividing them by mass (sex) in the process of preparing hybrid silkworm grain. By the method of mathematical statistics, the regularities of division of the mixture of breeding cocoons by caliber and weight are revealed. The normalized proportion of the average cocoons fraction of 58–70 % and its range of caliber – 2 mm was determined. The possibility of maximum separation of defective components with small and large fractions from the batch in two stages when sorting cocoons by caliber and mass on the developed devices was revealed. According to the results of production feedings, more cocoon yield was obtained (on average, by 10 kg per box (29 g) of grain). Moreover, there were more uniform and varietal cocoons (22 % and 13 % more than in the control variant, respectively). According to the results of unwinding, the total and continuously unwinding length of the cocoon thread in the experimental cocoons is, respectively, 20 and 27 % higher than in the control ones.


2020 ◽  
Vol 65 (4) ◽  
pp. 43-47
Author(s):  
S. Aleksanin ◽  
S. Serebryakova ◽  
I. Levashkina

Purpose: To find the distinctive features of the white matter tracts’ structural changes for Chernobyl accident liquidators with ebcephalopathy at the remote period using DT-MRI methods. Material and methods: Chernobyl accident liquidators group (41 subjects) and group of control (49 subjects), all subjects with stage II of encephalopathy, mean age of liquidators’ group 68.3 ± 6.9 years, gropup of control — 68.6 ± 5.8 years. All subjects were clinically examined to confirm encephalopathy stage, hypertension, diabetes (and prove patients of both groups have comparable level of damage of those deseases), as well as with routine MRI and DT-MRI protocols. According routine MRI results, all subjects of both groups had high level of discirculatory damages: multifocal lesions of white matter and periventricular leukoaraiosis, mixed replacement hydrocephalus. Results: Liquidator’s group average fraction anisotropy coefficient (CFA) had shown statistically significant reduction in four frontal and temporal lobe tracts of neocortex if compare with average CFA in the group of control: superior longitudinal fasciculi (р < 0.02); front sections of corona radiata (р < 0.02); anterior horn of internal capsule (р < 0.01), inferior longitudinal fasciculi (р < 0.01). Conclusion: Frontal and temporal lobe tracts of neocortex, responsible for cognitive processes, are the most sensible to accident liquidation negative factors. Cerebral structure changes, found for group of liquidators, are similar to elder people with encephalopathy, but are clnically more strongly marked, what proves hyoptesis of early aging of liquidators’ brain structures.


Author(s):  
N.M. Budnev ◽  
N.V. Volkov ◽  
A.A. Lagutin ◽  
E.Yu. Mordvin ◽  
R.I. Raikin ◽  
...  

The problem of exploring a territory for designing a full-scale gamma observatory is discussed. It is caused by the need to increase the sensitivity and energy threshold for detecting gamma rays of the existing TAIGA gamma observatory array. The study of astroclimatic conditions over the territory of the Khovsgol Aimag (Mongolia) was carried out for the purposes of performing nighttime astrophysical observations. Spatial distributions of cloudless events fraction and atmospheric water vapor content were obtained for several periods of active phases of astrophysical observations using the night-time data from the VIIRS instrument onboard Suomi NPP satellite as well as hyperspectrometer AIRS onboard Aqua satellite. Analysis of satellite data has shown that upon topographic and infrastructure criteria, the plateau of Lake Khuvsgul is the most suitable region for the deployment of a full-scale gamma-ray observatory with a hybrid detector system. According to VIIRS/SNPP data over the territory of interest for two seasons, it was revealed that the average fraction of cloudless events is about 65 % and the atmospheric water vapor content (according to AIRS/ Aqua data) is low, amounting to 2-2.5 kg/m2.


BMC Genomics ◽  
2020 ◽  
Vol 21 (S7) ◽  
Author(s):  
Kirill A. Danilov ◽  
Dimitri A. Nikogosov ◽  
Sergey V. Musienko ◽  
Ancha V. Baranova

Abstract Background Head-to-head comparison of BeadChip and WGS/WES genotyping techniques for their precision is far from straightforward. A tool for validation of high-throughput genotyping calls such as Sanger sequencing is neither scalable nor practical for large-scale DNA processing. Here we report a cross-validation analysis of genotyping calls obtained via Illumina GSA BeadChip and WGS (Illumina HiSeq X Ten) techniques. Results When compared to each other, the average precision and accuracy of BeadChip and WGS genotyping techniques exceeded 0.991 and 0.997, respectively. The average fraction of discordant variants for both platforms was found to be 0.639%. A sliding window approach was utilized to explore genomic regions not exceeding 500 bp encompassing a maximal amount of discordant variants for further validation by Sanger sequencing. Notably, 12 variants out of 26 located within eight identified regions were consistently discordant in related calls made by WGS and BeadChip. When Sanger sequenced, a total of 16 of these genotypes were successfully resolved, indicating that a precision of WGS and BeadChip genotyping for this genotype subset was at 0.81 and 0.5, respectively, with accuracy values of 0.87 and 0.61. Conclusions We conclude that WGS genotype calling exhibits higher overall precision within the selected variety of discordantly genotyped variants, though the amount of validated variants remained insufficient.


Author(s):  
M.E. Dyikanova ◽  
O.N. Ivashova ◽  
A.G. Levshin ◽  
I.N. Gasparyan ◽  
Sh.V. Gasparyan

Урожайность картофеля в России остается низкой из-за возделывания не только в производственных предприятиях, но и в личных подсобных хозяйствах (ЛПХ), где возделывание трудоемкое, неиндустриального типа. Однако картофель, выращиваемый в ЛПХ, может быть интегрирован в сегмент производства экологически чистого картофеля при поддержке Министерства сельского хозяйства РФ и переведен из сектора личного потребления в формат коммерческой деятельности. Особенность органического земледелия отказ в технологиях возделывания от использования любых химических соединений. Поэтому использование природного материала концентрата глауконитового песка Бондарского месторождения Тамбовской области становится все более актуально. Цель нашей работы изучить влияние концентрата глауконитовых песков на продуктивность картофеля. Исследования проводили в 20182019 годах на участке лаборатории овощеводства РГАУМСХА имени К.А. Тимирязева. Почвы дерново-подзолистые среднесуглинистые, мощность пахотного слоя 2022 см, легкогидролизуемого азота 9,3 мг на 100 г почвы, фосфора 15,0, калия 8,3 мг на 100 г почвы, содержание гумуса 2,6, рН сол. 5,8. Использовали сорт Удача с различными концентрациями глауконитовых песков (10 г/раст., 20 г/раст., 30 г/раст., 40 г/раст.). Повторность опытов трехкратная. Варианты в опыте были размещены рендомизированным методом. Площадь одной опытной делянки 25 м2. Схема посадки 7035 см. Густота стояния 46,7 тыс. растений на га. На посадку использовали семeна средней фракции (4080 г), элиту. Все варианты высажены одновременно в один год. Были проведены наблюдения и учеты фенологические, биометрические, структуры урожая. Технология возделывания стандартная. Установлено, что внесение природного минерала глауконитовых песков при возделывании картофеля раннего дает прибавку урожая до 30,2, лучшая норма 30 г/раст.The yield of potatoes in Russia remains low due to cultivation not only in production enterprises, but also in private farms, where cultivation is labor-intensive, non-industrial type. However, potatoes grown in PSP can be integrated into the segment of production of organic potatoes with the support of the Ministry of agriculture of the Russian Federation and transferred from the sector of personal consumption to the format of commercial activity. The peculiarity of organic farming is the refusal of cultivation technologies to use any chemical compounds. Therefore, the use of natural material-a concentrate of glauconite sand from the Bondar Deposit in the Tambov region is becoming more and more relevant. The purpose of our work is to study the effect of glauconite sand concentrate on potato productivity. The research was carried out in 20182019 on the site of the vegetable growing laboratory of the Russian State Agrarian University Moscow Timiryazev Agricultural Academy. Sod-podzolic soils are medium-loamy, the capacity of the arable layer is 2022 cm, easily hydrolyzed nitrogen is 9.3 mg per 100 g of soil, phosphorus is 15.0, potassium is 8.3 mg per 100 g of soil, humus content is 2.6, pH 5.8. We used the Udacha variety with different concentrations of glauconite sands (10 g/plant, 20 g/plant, 30 g/plant, 40 g/plant). The repeatability of experiments is three-fold. The variants in the experiment were placed by rendomized method. The area of one experimental plot is 25 m2. The planting scheme is 7035 cm. The density of standing 46.7 thousand plants per ha. Seeds of the average fraction (4080 g), elite, were used for planting. All variants are planted simultaneously in one year. Observations and records of phenological, biometric, and crop structure were made. Cultivation technology is standard. Adding the natural mineral glauconite sands when cultivating early potatoes gives an increase in yield up to 30.2, the best rate is 30 g/plant.


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