Thermal Adaptation of Dihydrofolate Reductase from the Moderate ThermophileGeobacillus stearothermophilus

The thermal melting temperature of dihydrofolate reductase from Geobacillus stearothermophilus (BsDHFR) is 30 °C higher than that of its homologue from the psychrophile Moritella profunda. Additional proline residues in the loop regions of BsDHFR have been proposed to enhance the thermostability of BsDHFR, but site-directed mutagenesis studies reveal that these proline residues contribute only minimally. Instead, the high thermal stability of BsDHFR is partly due to removal of water-accessible thermolabile residues such as glutamine and methionine, which are prone to hydrolysis or oxidation at high temperatures. The extra thermostability of BsDHFR can be obtained by ligand binding, or in the presence of salts or cosolvents such as glycerol and sucrose. The sum of all these incremental factors allows BsDHFR to function efficiently in the natural habitat of G. stearothermophilus, which is characterized by temperatures that can reach 75 °C

Determinants of Corporate Hedging: A (Statistical) Meta-Analysis

International audienceWhile literature provides several hedging theories, evidence on the corporate incentives to hedge remains ambiguous. We synthesize data of empirical studies via statistical meta-analysis to test different hedging hypotheses. To our knowledge, this constitutes the first application of such a methodology in financial economics. Our results imply that financial distress costs induce firms to hedge. We find weak evidence that the underinvestment problem and the dependence on costly external financing influence hedging behavior. Taxes and agency conflicts do not show explanatory power. Because statistical and narrative reviews yield different outcomes, we see various other application possibilities for meta-analysis in financial economics

What do we really know about the influence of environmental on financial performance? A meta-regression analysis (MRA)

International audienceno abstrac

Measurement matters – A meta-study of the determinants of corporate capital structure

International audienceThis study aggregates the mixed empirical evidence of the seven most commonly investigated determinants of corporate capital structure. We apply meta-regression analysis on a data set of 3,890 reported results, manually collected from 100 primary studies. Our results reveal that − in descending order of importance − tangible assets (positive sign), market-to-book ratio (negative sign), and profitability (negative sign) are significant determinants of corporate debt level. In addition, we find evidence for publication selection bias in academic literature. Accordingly, specific results are systematically overrepresented, as authors prefer reporting statistically significant estimates in line with theory or existing empirical results. Significant determinants, as well as publication selection bias, are more pronounced for characteristics like market-based measures of capital structure, total debt measures of capital structure, and for top articles in highly renowned journals, compared to book-based measures of capital structure or long-term debt measures of capital structure or randomly selected articles including more unknown and unpublished studies

What do we really know about corporate hedging? A multimethod meta-analytical study

International audienceno abstrac

What do we really know about corporate hedging? A multimethod meta-analytical study

International audienceThis paper employs meta-analysis to aggregate and systematically analyze the mixed empirical evidence on the determinants of corporate hedging reported in 132 previously published studies covering data from more than 73,000 firms. Among the fourteen proxy variables analyzed by multivariate meta-analysis, three variables emerge as reliable explanatory factors for corporate hedging decisions supporting the bankruptcy and financial distress hypothesis: dividend yield (positive sign), liquidity (negative sign), and firm size (positive sign). Moreover, for tax-loss carry forwards (positive sign) and research and development (positive sign), our findings indicate a weak impact on corporate hedging behavior reflecting tax reasons, the coordination between financing and investment, and agency conflicts between shareholders and debtholders. Regarding the asymmetric information and agency conflicts of equity hypothesis, we find no explanatory power. The further analysis of heterogeneity via meta-regression reveals several factors that determine the mixed empirical evidence reported in previous studies. First, the results indicate that studies analyzing firms from North America report, on average, a lower impact of leverage on the corporate hedging decision. Moreover, studies examining more recent data samples tend to find a weaker relation between tangible assets and hedging, R&D and hedging, respectively. Overall, our results encourage scientific research to put more emphasis on finer-grained examinations of hedging variations and to discover rationales of corporate hedging extending classical financial theories

Rather complements than substitutes: firm value effects of capital structure and financial hedging decisions

The aim of this study is to analyze the interaction between capital structure decisions and risk management decisions as well as the channels through which they add value to firms. Competing theories are considered in an integrated path model, which we test by means of meta-analytic structural equation modelling (MASEM). This meta-analysis is based on 6,312 reported results, which are manually collected from 411 empirical studies. We find that capital structure mediates the relation between corporate financial hedging and firm value. In this regard, active risk management positively affects leverage by providing greater debt capacities. Furthermore, leverage has a negative impact on firm value. Hence, capital structure and financial hedging decisions appear rather as complements instead of substitutes. This implies that managers should leave additional debt capacities unused and instead use additional internal funds arising from active risk management to carry out profitable projects and research and development activities. Overall, corporate hedging is found to especially add value to a firm by lowering bankruptcy risks and underinvestment risks

Development of a DNA array for the simultaneous detection and identification of sugar thick juice bacterial contaminants

Despite the use of generally accepted good storage practices, sugar thick juice degradation caused by microbiological contamination occasionally occurs, causing considerable financial loss. In this study, a DNA array was developed for simultaneous detection and identification of the most prominent microflora present during thick juice storage, which may cause degradation of the thick juice. Specific oligonucleotides were developed for several bacterial taxa, including the genera Bacillus, Kocuria, Staphylococcus and Tetragenococcus and the species Aerococcus viridans, Leuconostoc mesenteroides and Tetragenococcus halophilus. The DNA array was validated using both pure cultures and industrial samples. In addition, comparisons were made between the developed array, PCR assays specifically targeting the thick juice contaminants and classical microbial platings. The array was found to be reliable and sensitive enough to detect and identify the target bacteria. In addition, the array was used to monitor the target microbial populations in thick juice during longterm storage and degradation. Results are discussed in relation to DNA stability in thick juice.status: publishe