From Rich User Requirements to System Requirements

In recent years the usage of information systems has changed dramatically. Today many information systems are developed for non-organizational users. These wide-area end-users are often socially, as well as geographically very widely dispersed, which makes it for organizations that develop information systems extremely difficult to know who their users are, or what they expect. Previous research has claimed that rich user requirements information is necessary, in order to understand how to serve this audience right. However, at the same time current requirements engineering methods, capable of providing this rich information, do not serve the needs of designers and developers, who actually implement the services and who need precise knowledge of system requirements. It appears that there is a severe gap in the communication of requirements between end-user, analyst, and designer. We have the design science research agenda to develop a method for extending one advanced requirements engineering method, WARE, to provide support for the full spectrum of communication. Our study presents results of ongoing research program, studying the innovation possibilities of Mobile Presence technology. Our method enables analysts to make the transition from rich user requirements to system requirements, which designers and developers can use in their implementation work

On the significance of quantum effects and interactions for the apparent universality of Bloch laws for M_s(T)

The apparent universality of Bloch's T^{3/2}-law for the temperature dependence of the spontaneous magnetization, and of generalizations thereof, is considered. It is argued that in the derivation one should not only consider the exchange interaction between the spins, but also the other interactions between them, leading to elliptical spin precession and deviations from the parabolic dispersion of magnons. Also interaction effects are important to explain the apparent universality of generalized Bloch law exponents e_B, defined by M_s(T)= M_s(0)-const. x T^{e_B}, valid in a wide temperature range T_1 < T < T_2, and for dimensionalities d = 1, 2, and 3. The above-mentioned temperature range, the 'Bloch range', lies above the quantum range, where magnetic long-range order (e.g. in d=2 dimensions) is nontrivially enforced by the additional interactions, but below the thermal critical region, where universal 'anomalous scaling dimensions' apply. In contrast, for the Bloch temperature region, the universality is only apparent, i.e. a crossover-phenomenon, and simple scaling considerations with 'normal dimensions' apply. However, due to interactions, the Bloch exponent e_B depends not only on the dimensionality d of the system, but also on the spin quantum number s (mod (1/2)) of the system, i.e. for given d the Bloch exponent e_B is different for half-integer s and for integer s.Comment: LATEX, 27 pages (including 5 eps-figures); accepted by JMM

Quorum Sensing Controls Adaptive Immunity through the Regulation of Multiple CRISPR-Cas Systems

Bacteria commonly exist in high cell density populations, making them prone to viral predation and horizontal gene transfer (HGT) through transformation and conjugation. To combat these invaders, bacteria possess an arsenal of defenses, such as CRISPR-Cas adaptive immunity. Many bacterial populations coordinate their behavior as cell density increases, using quorum sensing (QS) signaling. In this study, we demonstrate that QS regulation results in increased expression of the type I-E, I-F, and III-A CRISPR-Cas systems in $\textit{Serratia}$ cells in high-density populations. Strains unable to communicate via QS were less effective at defending against invaders targeted by any of the three CRISPR-Cas systems. Additionally, the acquisition of immunity by the type I-E and I-F systems was impaired in the absence of QS signaling. We propose that bacteria can use chemical communication to modulate the balance between community-level defense requirements in high cell density populations and host fitness costs of basal CRISPR-Cas activity.This work was supported by a Rutherford Discovery Fellowship (P.C.F.) from the Royal Society of New Zealand (RSNZ) and the Marsden Fund, RSNZ. A.G.P. was supported by a University of Otago Doctoral Scholarship. G.P.C.S. is funded by the Biotechnology and Biological Sciences Research Council, UK

Brain Vitamin E Deficiency During Development Is Associated With Increased Glutamate Levels and Anxiety in Adult Mice

Vitamin E, the most important lipophilic radical scavenging antioxidant in vivo, has a pivotal role in brain. In an earlier study, we observed that adult mice with a defect in the gene encoding plasma phospholipid transfer protein (PLTP) display a moderate reduction in cerebral vitamin E levels, and exacerbated anxiety despite normal locomotion and memory functions. Here we sought to determine whether dietary vitamin E supplementation can modulate neurotransmitter levels and alleviate the increased anxiety phenotype of PLTP-deficient (PLTP−/−) mice. To address this question, a vitamin E-enriched diet was used, and two complementary approches were implemented: (i) “early supplementation”: neurotransmitter levels and anxiety were assessed in 6 months old PLTP−/− mice born from vitamin E-supplemented parents; and (ii) “late supplementation”: neurotransmitter levels and anxiety were assessed in 6 months old PLTP−/− mice fed a vitamin E-enriched diet from weaning. Our results show for the first time that an inadequate supply of vitamin E during development, due to moderate maternal vitamin E deficiency, is associated with reduced brain vitamin E levels at birth and irreversible alterations in brain glutamate levels. They also suggest this deficiency is associated with increased anxiety at adulthood. Thus, the present study leads to conclude on the importance of the micronutrient vitamin E during pregnancy

BRAND – search for BSM physics at TeV scale by exploring transverse polarization of electrons emitted in neutron decay

Neutron and nuclear beta decay correlation coefficients are linearly sensitive to the exotic scalar and tensor interactions that are not included in the Standard Model (SM). The proposed experiment will measure simultaneously 11 neutron correlation coefficients (a, a, B, D, H, L, N, R, S, U, V) where 7 of them (H, L, N, R, S, U, V) depend on the transverse electron polarization – a quantity that vanishes for the SM weak interaction. The neutron decay correlation coefficients H, L, S, U, V were never attempted experimentally before. The expected ultimate sensitivity of the proposed experiment that currently takes off on the cold neutron beamline PF1B at the Institut Laue-Langevin, Grenoble, France, is comparable to that of the planned electron spectrum shape measurements in neutron and nuclear β decays but offers completely different systematics and additional sensitivity to imaginary parts of the scalar and tensor couplings

Identification of Hammerhead Ribozymes in All Domains of Life Reveals Novel Structural Variations

Hammerhead ribozymes are small self-cleaving RNAs that promote strand scission by internal phosphoester transfer. Comparative sequence analysis was used to identify numerous additional representatives of this ribozyme class than were previously known, including the first representatives in fungi and archaea. Moreover, we have uncovered the first natural examples of “type II” hammerheads, and our findings reveal that this permuted form occurs in bacteria as frequently as type I and III architectures. We also identified a commonly occurring pseudoknot that forms a tertiary interaction critical for high-speed ribozyme activity. Genomic contexts of many hammerhead ribozymes indicate that they perform biological functions different from their known role in generating unit-length RNA transcripts of multimeric viroid and satellite virus genomes. In rare instances, nucleotide variation occurs at positions within the catalytic core that are otherwise strictly conserved, suggesting that core mutations are occasionally tolerated or preferred

Capturing Hammerhead Ribozyme Structures in Action by Modulating General Base Catalysis

We have obtained precatalytic (enzyme–substrate complex) and postcatalytic (enzyme–product complex) crystal structures of an active full-length hammerhead RNA that cleaves in the crystal. Using the natural satellite tobacco ringspot virus hammerhead RNA sequence, the self-cleavage reaction was modulated by substituting the general base of the ribozyme, G12, with A12, a purine variant with a much lower pKa that does not significantly perturb the ribozyme's atomic structure. The active, but slowly cleaving, ribozyme thus permitted isolation of enzyme–substrate and enzyme–product complexes without modifying the nucleophile or leaving group of the cleavage reaction, nor any other aspect of the substrate. The predissociation enzyme-product complex structure reveals RNA and metal ion interactions potentially relevant to transition-state stabilization that are absent in precatalytic structures

The SST-1M project for the Cherenkov Telescope Array

The SST-1M project, run by a Consortium of institutes from Czech Republic, Poland and Switzerland, has been proposed as a solution for implementing the small-size telescope array of the southern site of the Cherenkov Telescope Array. The technology is a pathfinder for efficient production of cost-effective imaging air Cherenkov telescopes. We report on the main system features and recent upgrades, the performances validation and the operation campaign carried out in 2018