Knowledge-intensive sectors and the role of collective performance-related pay

ABSTRACT

The main contribution of this study is showing that the efficiency effects of collective performance-related pay (CPRP) are more pronounced in knowledge-intensive service sectors (KISs) than in other sectors. The hypothesis is that human resource practices such as CPRP are particularly useful for enhancing firm performance when innovation-supporting knowledge is distributed among multiple skill sets and employee creativity, knowledge creation and knowledge sharing are key success factors for the firm. Cross-sectional estimates obtained for a national sample of approximately 3,800 Italian firms confirm this prediction. These results are validated by adopting a treatment effect approach to solve the self-selection problem.     

Modulating D-amino acid oxidase substrate specificity: production of an enzyme for analytical determination of all D-amino acids by directed evolution

Recent research on the flavoenzyme D-amino acid oxidase from Rhodotorula gracilis (RgDAAO) has revealed new, intriguing properties of this catalyst and offers novel biotechnological applications. Among them, the reaction of RgDAAO has been exploited in the analytical determination of the D-amino acid content in biological samples. However, because the enzyme does not oxidize acidic D-amino acids, it cannot be used to detect the total amount of D-amino acids. We now present the results obtained using a random mutagenesis approach to produce RgDAAO mutants with a broader substrate specificity. The libraries of RgDAAO mutants were generated by error-prone PCR, expressed in BL21(DE3)pLysS Escherichia coli cells and screened for their ability to oxidize different substrates by means of an activity assay. Five random mutants that have a 'modified' substrate specificity, more useful for the analytical determination of the entire content of D-amino acids than wild-type RgDAAO, have been isolated. With the only exception of Y223 and G199, none of the effective amino acid substitutions lie in segments predicted to interact directly with the bound substrate. The substitutions appear to cluster on the protein surface: it would not have been possible to predict that these substitutions would enhance DAAO activity. We can only conclude that these substitutions synergistically generate small structural changes that affect the dynamics and/or stability of the protein in a way that enhances substrate binding or subsequently catalytic turnover.     

Evolving Object-Oriented Designs with Refactorings

Refactorings are behavior-preserving program transformations that automate design evolution in object-oriented applications. Three kinds of design evolution are: schema transformations, design pattern microarchitectures, and the hot-spot-driven-approach. This research shows that all three are automatable with refactorings. A comprehensive list of refactorings for design evolution is provided and an analysis of supported schema transformations, design patterns, and hot-spot meta patterns is presented. Further, we evaluate whether refactoring technology can be transferred to the mainstream by restructuring non-trivial C++ applications. The applications that we examine were evolved manually by software engineers. We show that an equivalent evolution could be reproduced significantly faster and cheaper by applying a handful of general-purpose refactorings. In one application, over 14K lines of code were transformed automatically that otherwise would have been coded by hand. Our experiments identify benefits, limitations, and topics of further research related to the transfer of refactoring technology to a production environment.     

Lifting transformational models of product lines: a case study

Model driven engineering (MDE) of software product lines (SPLs) merges two increasing important paradigms that synthesize programs by transformation. MDE creates programs by transforming models, and SPLs elaborate programs by applying transformations called features. In this paper, we present the design and implementation of a transformational model of a product line of scalar vector graphics and JavaScript applications. We explain how we simplified our implementation by lifting selected features and their compositions from our original product line (whose implementations were complex) to features and their compositions of another product line (whose specifications were simple). We used operators to map higher-level features and their compositions to their lower-level counterparts. Doing so exposed commuting relationships among feature compositions in both product lines that helped validate our model and implementation.     

Co-occurrence and distribution of deoxynivalenol,nivalenol and zearalenone in wheat from Brazil

Fusarium mycotoxins deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) were investigated in wheat from the 2009 and 2010 crop years. Samples (n = 745) from commercial fields were collected in four wheat producing regions (WPR) which differed in weather conditions. Analyses were performed using HPLC-DAD. Contamination with ZEN, DON and NIV occurred in 56, 86 and 50%, respectively. Also, mean concentrations were different: DON = 1046 µg kg^?1, NIV < 100 µg kg^?1 and ZEN = 82 µg kg^?1. Co-occurrence of ZEN, DON and NIV was observed in 74% of the samples from 2009 and in 12% from 2010. Wet/cold region WPR I had the highest mycotoxin concentration. Wet/moderately hot region WPR II had the lowest mycotoxin levels. Furthermore, the mean concentration of each mycotoxin was higher in samples from 2009 as compared with those from 2010. Precipitation during flowering or harvest periods may explain these results.     

The GenVoca model of software-system generators

An emerging breed of generators synthesize complex software systems from libraries of reusable components. These generators, called GenVoca generators, produce high-performance software and offer substantial increases in productivity. GenVoca is a blueprint for creating domain-specific software component technologies. Predator and Adage are based directly on GenVoca. Experimental evidence from the Predator project supports claims of performance and productivity with this model     

Antioxidant properties of aminoethylcysteine ketimine decarboxylated dimer: a review

Aminoethylcysteine ketimine decarboxylated dimer is a natural sulfur-containing compound detected in human plasma and urine, in mammalian brain and in many common edible vegetables. Over the past decade many studies have been undertaken to identify its metabolic role. Attention has been focused on its antioxidant properties and on its reactivity against oxygen and nitrogen reactive species. These properties have been studied in different model systems starting from plasma lipoproteins to specific cellular lines. All these studies report that aminoethylcysteine ketimine decarboxylated dimer is able to interact both with reactive oxygen and nitrogen species (hydrogen peroxide, superoxide anion, hydroxyl radical, peroxynitrite and its derivatives). Its antioxidant activity is similar to that of Vitamin E while higher than other hydrophilic antioxidants, such as trolox and N-acetylcysteine.     

Dissection of the structural determinants involved in formation of the dimeric form of D-amino acid oxidase from Rhodotorula gracilis: role of the size of the {beta}F5-{beta}F6 loop

The role of the long loop connecting ß-strands F5and F6 (21 amino acids, Pro302–Leu–Asp–Arg–Thr–Lys–Ser–Pro–Leu–Ser–Leu–Gly–Arg–Gly–Ser–Ala–Arg–Ala–Ala–Lys–Glu322)present in Rhodotorula gracilis D-amino acid oxidase (RgDAAO)was investigated by site-directed mutagenesis. This loop wasproposed to play an important role in the ‘head-to-tail’monomer–monomer interaction of this dimeric flavoenzyme:in particular, by means of electrostatic interactions betweenpositively charged residues of the ßF5–ßF6loop of one monomer and negatively charged residues belongingto the