Towards Utility-Based Prioritization of Requirements in Open Source Environments

Peer reviewe

YPTB3816 of 'Yersinia pseudotuberculosis' strain IP32953 is a virulence-related metallo-oligopeptidase

Background: although bacterial peptidases are known to be produced by various microorganisms, including pathogenic bacteria, their role in bacterial physiology is not fully understood. In particular, oligopeptidases are thought to be mainly involved in degradation of short peptides e.g. leader peptides released during classical protein secretion pathways. The aim of this study was to investigate effects of inactivation of an oligopeptidase encoding gene opdA gene of Yersinia pseudotuberculosis on bacterial properties in vivo and in vitro, and to test dependence of the enzymatic activity of the respective purified enzyme on the presence of different divalent cations. Results: in this study we found that oligopeptidase OpdA of Yersinia pseudotuberculosis is required for bacterial virulence, whilst knocking out the respective gene did not have any effect on bacterial viability or growth rate in vitro. In addition, we studied enzymatic properties of this enzyme after expression and purification from E. coli. Using an enzyme depleted of contaminant divalent cations and different types of fluorescently labelled substrates, we found strong dependence of its activity on the presence of particular cations. Unexpectedly, Zn2+ showed stimulatory activity only at low concentrations, but inhibited the enzyme at higher concentrations. In contrast, Co2+, Ca2+ and Mn2+ stimulated activity at all concentrations tested, whilst Mg2+ revealed no effect on the enzyme activity at all concentrations used. Conclusions: the results of this study provide valuable contribution to the investigation of bacterial peptidases in general, and that of metallo-oligopeptidases in particular. This is the first study demonstrating that opdA in Yersinia pseudotuberculsosis is required for pathogenicity. The data reported are important for better understanding of the role of OpdA-like enzymes in pathogenesis in bacterial infections. Characterisation of this protein may serve as a basis for the development of novel antibacterials based on specific inhibition of this peptidase activity

Transverse Electronic Transport through DNA Nucleotides with Functionalized Graphene Electrodes

Graphene nanogaps and nanopores show potential for the purpose of electrical DNA sequencing, in particular because single-base resolution appears to be readily achievable. Here, we evaluated from first principles the advantages of a nanogap setup with functionalized graphene edges. To this end, we employed density functional theory and the non-equilibrium Green's function method to investigate the transverse conductance properties of the four nucleotides occurring in DNA when located between the opposing functionalized graphene electrodes. In particular, we determined the electrical tunneling current variation as a function of the applied bias and the associated differential conductance at a voltage which appears suitable to distinguish between the four nucleotides. Intriguingly, we observe for one of the nucleotides a negative differential resistance effect.Comment: 19 pages, 7 figure

An Overview of Recommender Systems in the Internet of Things

The Internet Of Things (IoT) is an emerging paradigm that envisions a networked infrastructure enabling different types of devices to be interconnected. It creates different kinds of artifacts (e.g., services and applications) in various application domains such as health monitoring, sports monitoring, animal monitoring, enhanced retail services, and smart homes. Recommendation technologies can help to more easily identify relevant artifacts and thus will become one of the key technologies in future IoT solutions. In this article, we provide an overview of existing applications of recommendation technologies in the IoT context and present new recommendation techniques on the basis of real-world IoT scenarios

REMOVAL OF BASIC BLUE 3 AND REACTIVE ORANGE 16 BY ADSORPTION ONTO QUARTENIZED SUGAR CANE BAGASSE

Abstract The effectiveness of using sugar cane bagasse, an agricultural by-product, as a sorbent to remove basic and reactive dyes from aqueous solution was studied. The quartenized sugar cane bagasse (QSB) is capable in removing both Basic Blue 3 (BB3) and Reactive Orange 16 (RO16). The sorption of dye solutions was strongly affected by pH, where the optimum pH is 6-8. The kinetics of the dye sorption processes fitted a pseudo-second order kinetic model. Results indicated that the adsorption isotherms fitted well into both the Langmuir and Freundlich isotherms. The removal of BB3 was favourable at higher temperature, indicating that the sorption process was endothermic. On the other hand, sorption of RO16 on QSB was more favourable at low temperature. Keywords: Sugar cane bagasse; quartenization; sorption; reactive dyes; basic dyes Abstrak Keberkesanan menggunakan sisa tebu, produk sampingan pertanian, sebagai penjerap untuk menyingkirkan pewarna basik dan reaktif daripada larutan telah dikaji. Sisa tebu yang diquarternasi (QSB) adalah berupaya untuk menyingkirkan keduadua pewarna Basik Biru 3 (BB3) dan Reaktif Oren 16 (RO16). Penjerapan pewarna adalah dipengaruhi oleh pH, di mana pH optimum ialah 6-8. Kinetik proses erapan pewarna didapati mengikut model kinetik tertib pseudo-kedua. Keputusan eksperimen menunjukkan bahawa isoterma penjerapan mematuhi kedua-dua isoterma Langmuir dan Freundlich. Penyingkiran BB3 adalah lebih baik pada suhu tinggi, menunjukkan proses erapan adalah endotermik. Manakala erapan RO16 ke atas QSB adalah lebih digemari pada suhu rendah

Don’t make me angry, you wouldn’t like me when I’m angry: volitional choices to act or inhibit are modulated by subliminal perception of emotional faces

Volitional action and self-control—feelings of acting according to one’s own intentions and in being control of one’s own actions—are fundamental aspects of human conscious experience. However, it is unknown whether high-level cognitive control mechanisms are affected by socially salient but nonconscious emotional cues. In this study, we manipulated free choice decisions to act or withhold an action by subliminally presenting emotional faces: In a novel version of the Go/NoGo paradigm, participants made speeded button-press responses to Go targets, withheld responses to NoGo targets, and made spontaneous, free choices to execute or withhold the response for Choice targets. Before each target, we presented emotional faces, backwards masked to render them nonconscious. In Intentional trials, subliminal angry faces made participants more likely to voluntarily withhold the action, whereas fearful and happy faces had no effects. In a second experiment, the faces were made supraliminal, which eliminated the effects of angry faces on volitional choices. A third experiment measured neural correlates of the effects of subliminal angry faces on intentional choice using EEG. After replicating the behavioural results found in Experiment 1, we identified a frontal-midline theta component—associated with cognitive control processes—which is present for volitional decisions, and is modulated by subliminal angry faces. This suggests a mechanism whereby subliminally presented “threat” stimuli affect conscious control processes. In summary, nonconscious perception of angry faces increases choices to inhibit, and subliminal influences on volitional action are deep seated and ecologically embedded