Statistical study of the results of radial keratotomy

The statistical study of 384 R.K. performed by the same surgeon shows that in 82% of R.K., preoperative myopia was between -1.5 to -6 diopters and in 77.5% of R.K., postoperative refraction was between -1 to +1. The 90% confidence interval was between -2 to +1 for all preoperative myopias and was the best when preoperative myopia was between -0.5 to -3 diopters (-1 to +1 D). The study of the stability and security shows that this surgical technique is stable and gives a good security.     

Computing the derivative of NURBS with respect to a knot

Algorithms for computing the derivative of NURBS with respect to a knot are presented. Rational and nonrational curves and surfaces as well as basis functions are differentiated with respect to a knot. The derivative entities are computed by control point or basis function differencing divided by appropriate knot spans.     

What makes a great journal great in the sciences? Which came first,the chicken or the egg?

The paper is concerned with analysing what makes a great journal great in the sciences, based on quantifiable Research Assessment Measures (RAM). Alternative RAM are discussed, with an emphasis on the Thomson Reuters ISI Web of Science database (hereafter ISI). Various ISI RAM that are calculated annually or updated daily are defined and analysed, including the classic 2-year impact factor (2YIF), 5-year impact factor (5YIF), Immediacy (or 0-year impact factor (0YIF)), Eigenfactor, Article Influence, C3PO (Citation Performance Per Paper Online), h-index, Zinfluence, PI-BETA (Papers Ignored—By Even The Authors), Impact Factor Inflation (IFI), and three new RAM, namely Historical Self-citation Threshold Approval Rating (H-STAR), 2 Year Self-citation Threshold Approval Rating (2Y-STAR), and Cited Article Influence (CAI). The RAM data are analysed for the 6 most highly cited journals in 20 highly-varied and well-known ISI categories in the sciences, where the journals are chosen on the basis of 2YIF. The application to these 20 ISI categories could be used as a template for other ISI categories in the sciences and social sciences, and as a benchmark for newer journals in a range of ISI disciplines. In addition to evaluating the 6 most highly cited journals in each of 20 ISI categories, the paper also highlights the similarities and differences in alternative RAM, finds that several RAM capture similar performance characteristics for the most highly cited scientific journals, determines that PI-BETA is not highly correlated with the other RAM, and hence conveys additional information regarding research performance. In order to provide a meta analysis summary of the RAM, which are predominantly ratios, harmonic mean rankings are presented of the 13 RAM for the 6 most highly cited journals in each of the 20 ISI categories. It is shown that emphasizing THE impact factor, specifically the 2-year impact factor, of a journal to the exclusion of other informative RAM can lead to a distorted evaluation of journal performance and influence on different disciplines, especially in view of inflated journal self citations.     

Starch Retrogradation: A Comprehensive Review

Starch retrogradation is a process in which disaggregated amylose and amylopectin chains in a gelatinized starch paste reassociate to form more ordered structures. Starch retrogradation has been the subject of intensive research over the last 50 years, mainly due to its detrimental effect on the sensory and storage qualities of many starchy foods. However, starch retrogadation is desirable for some starchy food products in terms of textural and nutritional properties. To better understand the effect of starch retrogradation on the quality of starchy foods, measurement methods of starch retrogradation and factors that influence starch retrogradation have been studied extensively. This article provides a comprehensive review of starch retrogradation including the definition of the process, molecular mechanisms of how it occurs, and measurement methods and factors that influence starch retrogradation. The review also discusses the effect of retrogradation on the in vitro enzyme digestibility of starch. Spectroscopic methods such as FTIR and Raman are considered to be very promising in characterizing starch retrogradation at a molecular level, although more studies are needed in the future.     

Properties of retrograded and acetylated starch preparations Part 2. Dynamics of saccharification with amyloglucosidase and rheological properties of resulting pastes and gels

Various procedures have been used to produce preparations of retrograded starch, by subjecting it to acetylation with methods used in the food industry. The resultant starch preparations were evaluated for their degree of acetylation through titration, swelling power and solubility in water at 80 °C, and saccharification dynamics as affected by amyloglucosidase. Rheological properties of pastes and gels of native starch and modified starch preparations were characterized with the use of a sweep temperature test as a dependency of the storage modulus (G′) and loss modulus (G″) on temperature. In addition, flow curves of pastes were plotted and mechanical spectra of gels of the preparations examined were determined. These modifications had a significant effect on the preparations produced. Retrograded and acetylated starch preparations were characterized by greater solubility in water and greater swelling power, and were less susceptible to amyloglucosidase than the non-acetylated preparations. Rheological properties of the pastes and gels were affected by the methods of their production. Acetylation was found to significantly affect a decrease in the storage modulus value during heating. Pastes of the native starch and modified starch preparations were characterized by the non-Newtonian flow, shear thinning with a tendency to yield stress. In turn, the mechanical spectra demonstrated that - in the concentration applied - both native starch and modified starch preparation were forming weak gels.     

Effects of genotype and growing locations on properties of wheat starch gels

This study examines the contributions of genotype and the effects of growing location and storage to variability in the strength, syneresis and in vitro enzyme digestibility of wheat (Triticum aestivum L.) starch gels. The study involved starch that was extracted from five wheat varieties grown in four locations. Length of storage at 4 °C after hydrothermal treatment of the starch accounted for 30–50% of the variance in the three gel properties. Genotype contributed significantly to variability in syneresis and enzyme digestibility of the starch gels, indicating a degree of heritability of these characteristics in the wheat varieties studied. Gel strength was strongly influenced by effects from the growing location. Syneresis and enzyme‐resistant starch were negatively correlated with granule size and swelling power of native starch. Syneresis was also correlated negatively with pasting viscosities of starch granules, and positively with amylose content and pasting temperature. Gel strength was correlated positively with relative crystallinity and negatively with the breakdown of peak viscosity. Length of storage had a major influence on gel strength, syneresis and in vitro enzyme digestibility, although genotype contributed significantly to variability in syneresis and enzyme‐digestibility. Growing conditions were a significant influence on gel strength.     

Non-Newtonian behaviour of heather honey

The aim of this research was to evaluate the rheological properties including viscoelasticity of heather honeys. It was stated that heather honeys exhibited non-Newtonian, shear-thinning behaviour with tendency to yield stress and they were thixotropic, as well. The parameters of the Herschel-Bulkley model describing flow behaviour of samples depended on the kind of honey, its water content, and the measurement temperature. Oscillatory rheology data revealed that the loss modulus predominated over the storage one in the whole frequency range. Moreover, significant dependence of complex viscosity on angular frequency confirmed non-Newtonian and viscoelastic behaviour of heather honeys.     

Experimental analysis of a film used as a threatening stimulus.

In an effort to identify sources of stress reaction, a threatening film depicting a primitive genital operation was analyzed experimentally by dividing it into 3 sections of different contents. Impact of the sections was compared on physiological and psychological measures of stress reaction. The threat value of the film depended not only on the genital operation scenes, interpreted by previous investigators as producing castration anxiety, but also upon other types of contents, such as nudity. Moreover, in addition to differing in degree of disturbance produced, the film sections resulted in variation in the pattern of affects. Such patterns cannot be studied at the physiological level of analysis. Personality factors also determined reactions to the film threats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)