Running Error Analysis of Evaluation Algorithms for Bivariate Polynomials in Barycentric Bernstein Form

Running error analysis for the bivariate de Casteljau algorithm and the VS algorithm is performed. Theoretical results joint with numerical experiments show the better stability properties of the de Casteljau algorithm for the evaluation of bivariate polynomials defined on a triangle in spite of the lower complexity of the VS algorithm. The sharpness of our running error bounds is shown.     

Isomerization of α-pinene,limonene, α-terpinene,and terpinolene on sulfated zirconia

Transformations of α-pinene, limonene, terpinolene, and α-terpinene were studied in liquid phase on sulfated zirconia having 15% H₂SO₄, with the aim of identifing the pathway of α-pinene isomerization. The principal products obtained in α-pinene isomerization were camphene, tricyclene, limonene, and terpinolene; the concentration maxima observed at 120°C and 180 min were 53, 6.1, 7.7, and 3.0%, respectively. The principal products formed in the limonene transformation after a 20-min reaction time were terpinolene, α-terpinene, and γ-terpinene; then the concentration of these products decreased. The terpinolene reaction yielded principally m-cymenene, whereas the α-terpinene transformation produced p-cymene. Studies of the initial rates of transformation of terpenes indicate a very high rate for α-pinene, intermediate for limonene and α-terpinene, and very low for terpinolene. The scheme proposed to interpret the results of the α-pinene isomerization reaction on sulfated zirconia is in agreement with reaction schemes proposed by A. Allahverdiev, S. Irandoust, and D. Y. Murzin (Isomerization of α-Pinene over Clinoptilolite.     

Age-related responses of vasoactive factors during acute exercise

To evaluate the age-related response of vasoactive factors during acute exercise, young (n = 8, aged 23.6+/-2 years) and old (n = 13, aged 77+/-6 years) healthy volunteers performed a stress test using a treadmill, and blood samples were taken before and after exercise. There were neither basal (old people 77+/-53 vs. young people 67.6+/-40 pg/ml) nor peak exercise-related (old people 77+/-43 vs. young people 66.8+/-34 pg/ml) differences in plasma adrenomedullin (AM) between both groups. AM did not increase with exercise in either group. Regarding plasma cAMP, there were neither basal nor exercise related differences, but this nucleotide increased with exercise in both groups (old people p < 0.0001, young people p < 0.05). Plasma Atrial Natriuretic Peptide (ANP) was higher in basal (116.3+/-64 vs. 46.8+/-21 pg/ml, p < 0.003) and after exercise samples (150.2+/-76.5 vs. 68.7+/-29.5 pg/ml, p < 0.004) in old people as compared with young people. Old people showed an increase in ANP with exercise (p < 0.05), but in young people, though there was a trend to increase, it did not reach statistical significance. There were neither basal nor exercise related differences in plasma cGMP, but this nucleotide increased with exercise in both groups. Angiotensin II (AT-II) levels were lower in basal and after exercise samples in old people as compared with young people. AT-II levels did not increase with exercise in either group. These data suggest that, with increasing age, the vascular tree develops resistance to ANP and higher sensitivity to AT-II, while AM levels do not change. Exercise makes ANP changes more evident, while AM and AT-II are not modified.     

Long-term aging of Ag/a-C:H:O nanocomposite coatings in air and in aqueous environment

Nanocomposite coatings of silver particles embedded in a plasma polymer matrix possess interesting properties depending on their microstructure. The film microstructure is affected among others also by the RF power supplied during the deposition, as shown by transmission electron microscopy. The optical properties are characterized by UV–vis–NIR spectroscopy. An anomalous optical absorption peak from the Ag nanoparticles is observed and related to the microstructure of the nanocomposite films. Furthermore, a long-term aging of the coatings is studied in-depth in ambient air and in aqueous environments. It is shown that the studied films are not entirely stable. The deposition conditions and the microstructure of the films affect the processes taking place during their aging in both environments.     

A Further Decrease in the Catalyst Loading for the Palladium‐Catalyzed Direct Intramolecular Arylation of Amides and Sulfonamides

The direct arylation of N‐substituted o‐bromobenzanilides and benzenesulfonamides via C H bond functionalization has been developed using very low catalyst loadings. This novel cost‐effective and more sustainable method relies on a PCN‐type palladium pincer complex as a highly active palladium source, providing a general and efficient access to phenanthridinones, biaryl sultams and related heterocyclic systems. The beneficial effect of water as cosolvent has been observed in this process, which is not seriously influenced by electronic effects at the arene moieties or sterically demanding substituents at the amide or sulfonamide nitrogen. In addition, a number of experiments (kinetic plot, poisoning assays, TEM, ESI) have been performed in order to understand the role of the employed palladium complex in this reaction.

     

25th Anniversary Article: Double Emulsion Templated Solid Microcapsules: Mechanics And Controlled Release

How droplet microfluidics can be used to fabricate solid‐shelled microcapsules having precisely controlled release behavior is described. Glass capillary devices enable the production of monodisperse double emulsion drops, which can then be used as templates for microcapsule formation. The exquisite control afforded by microfluidics can be used to tune the compositions and geometrical characteristics of the microcapsules with exceptional precision. The use of this approach to fabricate microcapsules that only release their contents when exposed to a specific stimulus – such as a change in temperature, exposure to light, a change in the chemical environment, or an external stress – only after a prescribed time delay, and at a prescribed rate is reviewed.     

Copper Pincer Complexes as Advantageous Catalysts for the Heteroannulation of ortho‐Halophenols and Alkynes

A new, non‐symmetrical copper(II) pincer complex catalyzes much more efficiently the formation of benzofuran by the reaction between ortho‐iodophenols and alkynes. The lowest catalyst loadings are realized for this reaction, and bromo‐ and chlorophenols are heteroannulated for the first time. Strong evidence for hydrophenoxylation and intramolecular halogen atom‐transfer steps catalyzed by this remarkably active, recyclable homogeneous catalyst is provided.

     

Intraindividual variability in cognitive performance in older adults: Comparison of adults with mild dementia, adults with arthritis, and healthy adults.

Intraindividual variability in latency and accuracy of cognitive performance across both trials and occasions was examined in 3 groups of older adults: healthy adults, adults with arthritis, and adults diagnosed with mild dementia. Participants completed 2 reaction-time and 2 episodic-memory tasks on 4 occasions. Results indicated that intraindividual variability in latency was greater in individuals diagnosed with mild dementia than in adults who were neurologically intact, regardless of their health status. Individual differences in variability were stable over time and across cognitive domains. Intraindividual variability was also related to level of performance and was uniquely predictive of neurological status, independent of level of performance. Results suggest that intraindividual variability may be a behavioral indicator of compromised neurological mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performing an environmental tax reform in a regional economy. A computable general equilibrium approach

We use a Computable General Equilibrium model to simulate the effects of an Environmental Tax Reform in a regional economy (Andalusia, Spain). The reform involves imposing a tax on CO₂ or SO₂ emissions and reducing either the Income Tax or the payroll tax of employers to Social Security, and eventually keeping public deficit unchanged. This approach enables us to test the so-called double dividend hypothesis, which states that this kind of reform is likely to improve both environmental and non-environmental welfare. In the economy under analysis, an employment double dividend arises when the payroll tax is reduced and, if CO₂ emissions are selected as environmental target, a (limited) strong double dividend could also be obtained. No double dividend appears when Income Tax is reduced to compensate the environmental tax.