The many dimensions of laboratories’ interdisciplinarity

Interdisciplinarity is as trendy as it is difficult to define. Instead of trying to capture a multidimensional object with a single indicator, we propose six indicators, combining three different operationalizations of a discipline, two levels (article or laboratory) of integration of these disciplines and two measures of interdisciplinary diversity. This leads to a more meaningful characterization of the interdisciplinarity of laboratories’ publication practices. Thanks to a statistical analysis of these indicators on 600 CNRS laboratories, we suggest that, besides an average value of interdisciplinarity, different laboratories can be mainly distinguished by the “distance” between the disciplines in which they publish and by the scale at which interdisciplinary integration is achieved (article or laboratory).     

On peer review in computer science: analysis of its effectiveness and suggestions for improvement

In this paper we focus on the analysis of peer reviews and reviewers behaviour in a number of different review processes. More specifically, we report on the development, definition and rationale of a theoretical model for peer review processes to support the identification of appropriate metrics to assess the processes main characteristics in order to render peer review more transparent and understandable. Together with known metrics and techniques we introduce new ones to assess the overall quality (i.e. ,reliability, fairness, validity) and efficiency of peer review processes e.g. the robustness of the process, the degree of agreement/disagreement among reviewers, or positive/negative bias in the reviewers’ decision making process. We also check the ability of peer review to assess the impact of papers in subsequent years. We apply the proposed model and analysis framework to a large reviews data set from ten different conferences in computer science for a total of ca. 9,000 reviews on ca. 2,800 submitted contributions. We discuss the implications of the results and their potential use toward improving the analysed peer review processes. A number of interesting results were found, in particular: (1) a low correlation between peer review outcome and impact in time of the accepted contributions; (2) the influence of the assessment scale on the way how reviewers gave marks; (3) the effect and impact of rating bias, i.e. reviewers who constantly give lower/higher marks w.r.t. all other reviewers; (4) the effectiveness of statistical approaches to optimize some process parameters (e.g. ,number of papers per reviewer) to improve the process overall quality while maintaining the overall effort under control. Based on the lessons learned, we suggest ways to improve the overall quality of peer-review through procedures that can be easily implemented in current editorial management systems.     

Mechanism Controlling High-Temperature Degradation of Sunflower Oil Triacylglycerols in the Absence of Oxygen

The aim of the present study is to describe the mechanism controlling heat-induced formation of sunflower oil triacylglycerol and fatty acid methyl ester oligomers. The unique combination of high-performance size-exclusion chromatography with hyphenated electrospray ionization mass spectrometry (MS), atmospheric pressure chemical ionization-MS, and high-temperature gas chromatography-MS techniques allows differentiating between radical coupling species and Diels–Alder cycloadducts. Targeted analysis of thermally degraded sunflower oils confirms the exact structures of various acyclic oligomers accompanied by less-abundant products of pericyclic transformations. A series of model experiments simulate the impact of dienophile nature on the course of Diels–Alder reactions. Thus, α-tocopherylquinone, δ-tocopherylquinone, and methyl-(E)-11-oxoundec-9-enoate are synthesized as naturally occurring dienophiles bearing electron-withdrawing groups. The geometry of poor dienophiles does not affect concerted cyclization, while the structure of electron deficient dienophiles can overcome low reactivity. Practical Application: In the absence of oxygen, heat-induced degradation of polyunsaturated triacylglycerols proceed predominantly via a radical pathway, whereas concerted reactions represent minor mechanisms. Sunflower oil triacylglycerol molecules in the system without propagation stage can be effectively protected by natural and/or synthetic antioxidants. Application of chelates is also recommended. However, antioxidant-derived quinones, such as α-tocopherylquinone, can enter the Diels–Alder reaction even more easily than dienophiles without electron-withdrawing groups. Unsaturated core aldehydes possess the same reactivity. Examination of the mechanism controlling high-temperature degradation of triacylglycerols is especially important for processing engineers in edible oil refineries and food technologists. New perspective may help them to minimize undesirable changes in polyunsaturated species.     

Modification of Thin Film Composite PVA/PAN Membranes for Pervaporation Using Aluminosilicate Nanoparticles

The effect of the modification of the polyvinyl alcohol (PVA) selective layer of thin film composite (TFC) membranes by aluminosilicate (Al₂O₃·SiO₂) nanoparticles on the structure and pervaporation performance was studied. For the first time, PVA-Al₂O₃·SiO₂/polyacrylonitrile (PAN) thin film nanocomposite (TFN) membranes for pervaporation separation of ethanol/water mixture were developed via the formation of the selective layer in dynamic mode. Selective layers of PVA/PAN and PVA-Al₂O₃·SiO₂/PAN membranes were formed via filtration of PVA aqueous solutions or PVA-Al₂O₃·SiO₂ aqueous dispersions through the ultrafiltration PAN membrane for 10 min at 0.3 MPa in dead-end mode. Average particle size and zeta potential of aluminosilicate nanoparticles in PVA aqueous solution were analyzed using the dynamic light scattering technique. Structure and surface properties of membranes were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle measurements. Membrane performance was investigated in pervaporation dehydration of ethanol/water mixtures in the broad concentration range. It was found that flux of TFN membranes decreased with addition of Al₂O₃·SiO₂ nanoparticles into the selective layer due to the increase in selective layer thickness. However, ethanol/water separation factor of TFN membranes was found to be significantly higher compared to the reference TFC membrane in the whole range of studied ethanol/water feed mixtures with different concentrations, which is attributed to the increase in membrane hydrophilicity. It was found that developed PVA-Al₂O₃·SiO₂/PAN TFN membranes were more stable in the dehydration of ethanol in the whole range of investigated concentrations as well as at different temperatures of the feed mixtures (25 °C, 35 °C, 50 °C) compared to the reference membrane which is due to the additional cross-linking of the selective layer by formation hydrogen and donor-acceptor bonds between aluminosilicate nanoparticles and PVA macromolecules.     

Model comprehension for security risk assessment: an empirical comparison of tabular vs. graphical representations

Tabular and graphical representations are used to communicate security risk assessments for IT systems. However, there is no consensus on which type of representation better supports the comprehension of risks (such as the relationships between threats, vulnerabilities and security controls). Cognitive fit theory predicts that spatial relationships should be better captured by graphs. In this paper we report the results of two studies performed in two countries with 69 and 83 participants respectively, in which we assessed the effectiveness of tabular and graphical representations with respect to extraction correct information about security risks. The experimental results show that tabular risk models are more effective than the graphical ones with respect to simple comprehension tasks and in some cases are more effective for complex comprehension tasks. We explain our findings by proposing a simple extension of Vessey’s cognitive fit theory as some linear spatial relationships could be also captured by tabular models.     

Completion of overdetermined parabolic PDEs

In this paper we apply methods of commutative algebra to analysis of systems of PDEs. More precisely, we show that systems which are parabolic in a generalized sense are equivalent to certain completed systems which are parabolic in the standard sense. We also propose a constructive method for getting this completion, and Gröbner basis methods, via symbol modules of the systems, play a central role in practical computations. Moreover, we can easily construct systems which are not parabolic in the generalized sense but nevertheless become parabolic when completed.     

Localization and Spectroscopic Analysis of the Cu(I) Binding Site in Wheat Metallothionein Ec-1

The early cysteine-labeled metallothionein (MT) from Triticum aestivum (common wheat), denoted E_c-1, features two structurally well-defined domains, γ and β_E, coordinating two and four Zn(II) ions, respectively. While the protein is currently assumed to function mainly in zinc homeostasis, a low amount of copper ions was also recently detected in a native E_c-1 sample. To evaluate the observed copper binding in more detail, the recombinant Zn₆E_c-1 form was exposed to different amounts of Cu(I) ions and the resulting species characterized with spectroscopic methods. Data reveal that the first Cu(I) equivalent coordinates exclusively to the N-terminal γ-domain of the protein and replaces one Zn(II) ion. To analyze the ability of the γ-domain for coordination of monovalent metal ions in more detail, the γ-E_c-1 peptide fragment was incubated with increasing amounts of Cu(I) and the process monitored with UV–VIS, circular dichroism, and luminescence spectroscopy. Closely similar spectra are observed regardless if the apo- or the metal ion-loaded and, hence, pre-folded forms, were used for the titration experiments with Cu(I). The results indicate that low amounts of Cu(I) ions displace the two metal ions subsequently and stoichiometrically, despite the different coordination geometry requirements of Cu(I) and Zn(II).     

ConSpec – A Formal Language for Policy Specification

The paper presents ConSpec, an automata based policy specification language. The language trades off clean semantics to language expressiveness; a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various policy enforcement techniques.