Search results for "COMPOSITION"

Influence of Duration of Experiment on Rate of Uptake of Radioactive Potassium in Smooth Muscle

1963

THE rates of uptake and loss of radioactive tracers by excitable tissues can often be described by a function involving one exponential term1–3, but over relatively long periods deviations have been observed from such a simple course4–7. The rates of exchange towards the end of such periods are commonly slower than would be predicted from the initial rates and two general causes for this behaviour have been suggested: either the rates are, in fact, diminishing during the course of an experiment or the tissue is not behaving uniformly. This latter possibility has been extensively investigated1,8–15, because biological material shows an obvious lack of uniformity, and because deviations from …

Serum basal hormone concentrations and muscle mass in aging women: Effects of strength training and diet

2006

This study examined the effects of strength training and diet on serum basal hormone concentrations and muscle mass in aging women. Fifty-one women age 49 to 74 y were divided into two groups: strength training and nutritional counseling (n = 25), and strength training (n = 26). Both groups performed strength training twice a week for 21 wk. Nutritional counseling was given to attain sufficient energy and protein intake and recommended intake of fat and fiber. We found that the cross-sectional area of the quadriceps femoris increased by 9.5 ± 4.1% in the nutritional counseling group versus 6.8 ± 3.5% in the strength training only group after training (P < 0.052). Nutritional counseling e…

Earth system data cubes unravel global multivariate dynamics

2020

Understanding Earth system dynamics in light of ongoing human intervention and dependency remains a major scientific challenge. The unprecedented availability of data streams describing different facets of the Earth now offers fundamentally new avenues to address this quest. However, several practical hurdles, especially the lack of data interoperability, limit the joint potential of these data streams. Today, many initiatives within and beyond the Earth system sciences are exploring new approaches to overcome these hurdles and meet the growing interdisciplinary need for data-intensive research; using data cubes is one promising avenue. Here, we introduce the concept of Earth system data cu…

Case study: inorganic pollutants associated with particulate matter from an area near a petrochemical plant.

2004

The area of Gela (Sicily, Italy) contains one of the largest petroleum refineries in Europe and also has several oil fields both on land and offshore. This paper discusses how the oil refinery and traffic-related air pollution affect the chemical composition of airborne particulate matter over the town of Gela, using pine needles and urban road dust as the means of survey. Forty-one samples of pine needles from Pinus halepensis (Mill.) and two composite samples of roadway dust, each subdivided into six size fractions, were analyzed for major and trace elements. Information on the natural or anthropogenic origin of the observed heavy metals was deduced from factor analysis and element distri…

Dust, Metals and Metalloids in the Environment: From Air to Hair .

2013

Billions tons of particulate matter, made up of inorganic and organic compounds, are released every year into the atmosphere, from both anthropogenic and natural sources. The latter, which include geogenic material from erosion, agriculture, sea spray and volcanic activity, account for about 97% of the total mass of particles. The contribution of anthropogenic sources, about 3%, is more pronounced in industrialised and also in urban areas, where vehicular traffic is one of the most important sources. When examining the health impact, in addition to mass level and size, two other main characteristics of particulate matter need to be considered: its nature and chemical composition. These para…

Aroma release in the oral cavity after wine intake is influenced by wine matrix composition

2018

The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a “wine intake-like” situation. Aroma released after exposing the oral cavity of three individuals to different wines (n = 12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated t…

Invertibility in tensor products of Q-algebras

2002

On the Estimation of the Volatility-Growth Link

2012

It is common practice to estimate the volatility-growth link by specifying a standard growth equation such that the variance of the error term appears as an explanatory variable in this growth equation. The variance in turn is modeled by a second equation. Hardly any of existing applications of this framework includes exogenous controls in this second variance equation. Our theoretical findings suggest that the absence of relevant explanatory variables in the variance equation leads to a biased and inconsistent estimate of the volatility-growth link. Our simulations show that this effect is large. Once the appropriate controls are included in the variance equation consistency is restored. I…

Insights into the decomposition pathway of a lutetium alkylamido complex via intramolecular C–H bond activation

2017

Abstract Synthesis, characterization and reaction chemistry of lutetium alkylamido LLu(CH2SiMe3)(NHCPh3) (2), L = 2,5-[Ph2P=N(4-iPrC6H4)]2N(C4H2)–, is reported. Complex 2 undergoes cyclometalation of the NHCPh3 ligand at elevated temperatures to produce the orthometalated complex LLu(κ2−N,C-(NHCPh2(C6H4))) (3) which converts to 0.5 equivalents of bis(amido) LLu(NHCPh3)2 (4) upon heating at 80 °C for 24 h. Reaction of complex 2 with 4-dimethylaminopyridine (DMAP) does not promote alkane elimination nor imido formation. A kinetic analysis of the thermal decomposition of complex 2, supported by deuterium labelling studies and computational analysis (PBE0/def2-TZVP/SDD(Lu)), indicate direct Csp…

Finite-Size and Illumination Conditions Effects in All-Dielectric Metasurfaces

2022

Dielectric metasurfaces have emerged as a promising alternative to their plasmonic counterparts due to lower ohmic losses, which hinder sensing applications and nonlinear frequency conversion, and their larger flexibility to shape the emission pattern in the visible regime. To date, the computational cost of full-wave numerical simulations has forced the exploitation of the Floquet theorem, which implies infinitely periodic structures, in designing such devices. In this work, we show the potential pitfalls of this approach when considering finite-size metasurfaces and beam-like illumination conditions, in contrast to the typical infinite plane-wave illumination compatible with the Floquet t…