Korovkin type approximation theorems in weighted spaces via power series method

In this paper we consider power series method which is also member of the class of all continuous summability methods. We study a Korovkin type approximation theorem for a sequence of positive linear operators acting from a weighted space Cρ1 into a weighted space Bρ2 with the use of the power series method which includes both Abel and Borel methods. We also consider the rates of convergence of these operators. © 2018, Element D.O.O.. All rights reserved

Medial olivocochlear suppression in musicians versus non-musicians

The medial olivocochlear efferent (MOCE) branch synapses with outer hair cells (OHCs), and the efferent pathway can be activated via a contralateral acoustic stimulus (CAS). The activation of MOCE can change OHC motile responses and convert signals that are capable of controlling the sensitivity of the peripheral hearing system in a frequency-specific manner. The aim of this study was to examine the MOCE system activity in professional musicians using transient evoked otoacoustic emission test and CAS. Musician group showed stronger suppression in all frequency bands in the presence of CAS

Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed

We investigated rates and controls on greenhouse gas (CO2 and CH4) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the watershed had higher pH and higher porewater ion concentrations than soil collected from a bog‐like peat plateau at the top of the hillslope. The influence of these contrasting geochemical and topographic environments on CO2 and CH4 production was tested in soil microcosms by incubating both the organic‐ and mineral‐layer soils anaerobically for 55 days. Nitrogen (as NH4Cl) was added to half of the microcosms to test potential effects of N limitation on microbial greenhouse gas production. We found that the organic toeslope soils produced more CO2 and CH4, fueled by higher pH and higher concentrations of water‐extractable organic C (WEOC). Our results also indicate N limitation on CO2 production in the peat plateau soils but not the toeslope soils. Together these results suggest that the weathering and leaching of ions and nutrients from tundra hillslopes can increase the rate of anaerobic soil organic matter decomposition in downslope soils by (1) increasing the pH of soil porewater; (2) providing bioavailable WEOC and fermentation products such as acetate; and (3) relieving microbial N limitation through nutrient runoff. We conclude that the soil geochemistry as mediated by landscape position is an important factor influencing the rate and magnitude of greenhouse gas production in tundra soils

Co-firing of biomass with coals Part 1. Thermogravimetric kinetic analysis of combustion of fir (abies bornmulleriana) wood

The chemical composition and reactivity of fir (Abies bornmulleriana) wood under non-isothermal thermogravimetric (TG) conditions were studied. Oxidation of the wood sample at temperatures near 600 A degrees C caused the loss of aliphatics from the structure of the wood and created a char heavily containing C-O functionalities and of highly aromatic character. On-line FTIR recordings of the combustion of wood indicated the oxidation of carbonaceous and hydrogen content of the wood and release of some hydrocarbons due to pyrolysis reactions that occurred during combustion of the wood. TG analysis was used to study combustion of fir wood. Non-isothermal TG data were used to evaluate the kinetics of the combustion of this carbonaceous material. The article reports application of Ozawa-Flynn-Wall model to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustion of the fir wood. The average activation energy related to fir wood combustion was 128.9 kJ/mol, and the average reaction order for the combustion of wood was calculated as 0.30

Stability of the monoclinic phase in the ferroelectric perovskite PbZr(1-x)TixO3

Recent structural studies of ferroelectric PbZr(1-x)TixO3 (PZT) with x= 0.48, have revealed a new monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper, the stability region of all three phases has been established from high resolution synchrotron x-ray powder diffraction measurements on a series of highly homogeneous samples with 0.42 <=x<= 0.52. At 20K the monoclinic phase is stable in the range 0.46 <=x<= 0.51, and this range narrows as the temperature is increased. A first-order phase transition from tetragonal to rhombohedral symmetry is observed only for x= 0.45. The MPB, therefore, corresponds not to the tetragonal-rhombohedral phase boundary, but instead to the boundary between the tetragonal and monoclinic phases for 0.46 <=x<= 0.51. This result provides important insight into the close relationship between the monoclinic phase and the striking piezoelectric properties of PZT; in particular, investigations of poled samples have shown that the monoclinic distortion is the origin of the unusually high piezoelectric response of PZT.Comment: REVTeX file, 7 figures embedde

Rose oil inhalation protects against formaldehyde-induced testicular damage in rats

In this experimental study, harmful effects of formaldehyde (FA) inhalation on sperm concentration, sperm quality, serum testosterone levels and the rat testes were investigated. In addition, the possible protective effects of rose oil against to these harmful effects were evaluated. For this purpose, 21 albino-Wistar rats were used. The rats in Group I were used as control group. When the rats of Group II were exposed FA (10 ppm/1 h) for 35 days, the rats of Group III inhalated rose oil (1 ml/1 h) after FA. The epididymal tissues were taken for sperm analysing and the testes were removed for histological examination. In addition, testosterone levels were determined from the blood samples. Although the testosterone levels, the epididymal sperm concentration, and the progressive sperm motility significantly decreased, the abnormal sperm rate significantly increased in the Group II when compared to Group I. In the Group III, these damages were seen less. When the rats in the Group II compared with the control group, there were serious histological damages. In the Group III, it was determined that the histological changes were less than group II. It can be expressed that serious damages occurred via formaldehyde exposure in male reproductive system and that the rose oil had protective effects against these damages

Biogeosciences perspectives on integrated, coordinated, open, networked (ICON) science

This article is composed of three independent commentaries about the state of ICON principles (Goldman et al. 2021) in the AGU Biogeosciences section and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: Global collaboration, technology transfer and application (Section 2), Community engagement, citizen science, education, and stakeholder involvement (Section 3), and Field, experimental, remote sensing, and real-time data research and application (Section 4). We discuss needs and strategies for implementing ICON and outline short- and long-term goals. The inclusion of global data and international community engagement are key to tackle grand challenges in biogeosciences. Although recent technological advances and growing open-access information across the world have enabled global collaborations to some extent, several barriers ranging from technical to organizational to cultural have remained in advancing interoperability and tangible scientific progress in biogeosciences. Overcoming these hurdles is necessary to address pressing large-scale research questions and applications in the biogeosciences, where ICON principles are essential. Here, we list several opportunities for ICON, including coordinated experimentation and field observations across global sites, that are ripe for implementation in biogeosciences as a means to scientific advancements and social progress

Biogeosciences Perspectives on Integrated, Coordinated, Open, Networked (ICON) Science

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles in the American Geophysical Union Biogeosciences section, and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (a) Global collaboration, technology transfer, and application (Section 2), (b) Community engagement, community science, education, and stakeholder involvement (Section 3), and (c) Field, experimental, remote sensing, and real-time data research and application (Section 4). We discuss needs and strategies for implementing ICON and outline short- and long-term goals. The inclusion of global data and international community engagement are key to tackling grand challenges in biogeosciences. Although recent technological advances and growing open-access information across the world have enabled global collaborations to some extent, several barriers, ranging from technical to organizational to cultural, have remained in advancing interoperability and tangible scientific progress in biogeosciences. Overcoming these hurdles is necessary to address pressing large-scale research questions and applications in the biogeosciences, where ICON principles are essential. Here, we list several opportunities for ICON, including coordinated experimentation and field observations across global sites, that are ripe for implementation in biogeosciences as a means to scientific advancements and social progress

Age, gender and disability predict future disability in older people: the Rotterdam Study

<p>Abstract</p> <p>Background</p> <p>To develop a prediction model that predicts disability in community-dwelling older people. Insight in the predictors of disability is needed to target preventive strategies for people at increased risk.</p> <p>Methods</p> <p>Data were obtained from the Rotterdam Study, including subjects of 55 years and over. Subjects who had complete data for sociodemographic factors, life style variables, health conditions, disability status at baseline and complete data for disability at follow-up were included in the analysis. Disability was expressed as a Disability Index (DI) measured with the Health Assessment Questionnaire.</p> <p>We used a multivariable polytomous logistic regression to derive a basic prediction model and an extended prediction model. Finally we developed readily applicable score charts for the calculation of outcome probabilities.</p> <p>Results</p> <p>Of the 5027 subjects included, 49% had no disability, 18% had mild disability, 16% had severe disability and 18% had deceased at follow-up after six years. The strongest predictors were age and prior disability. The contribution of other predictors was relatively small. The discriminative ability of the basic model was high; the extended model did not enhance predictive ability.</p> <p>Conclusion</p> <p>As prior disability status predicts future disability status, interventive strategies should be aimed at preventing disability in the first place.</p