Controlled release of free-falling test models

Releasing device, powered by a drill motor through an adjustable speed reducer, has a spinning release head with three retractable spring-loaded fingers. The fingers are retracted by manual triggering of a cable at the motor end of the unit

Comparison of consumer attitudes between Cyprus and Latvia: An evaluation of effect of setting on consumer preferences in the water industry

This is the post-print version of the article. The official published version can be obtained from th link below - Copyright @ SpringerModels approaching consumer expectations of their water supplier from a risk perspective suggest that consumers primarily and overwhelmingly want safe drinking water supply. In this study consumer preferences in the water sector are investigated in two contrasting case studies: Cyprus, where there have been significant quantity and continuity of supply issues, and Riga, where there have been water quality issues. While water quality is undoubtedly the main priority of water consumers in Riga, in Cyprus consumers indicate that they prioritise a more reliable service even though many are sufficiently dissatisfied with water quality that they do not drink the tap water. The analysis of consumer attitudes in the two case studies suggests that when water supply is unreliable, reliability takes precedence; once it is reliable quality issues come to the fore.This research was carried out as part of Work Area 6 of the TECHNEAU project, an integrated project funded under FP6 of the European Commission, grant number: 018320

Consumer trust and confidence: Some recent ideas in the literature

This is a post-print version of the article. The official published version can be accessed from the link below - © IWA Publishing 2008This paper reflects on two recent debates in the consumer literature on trust that have implications for consumer relations in the water industry. The first concerns an important yet seldom made distinction between trust and confidence. The second concerns when and how trust is related to acceptance of, for example, new tariffs or new technologies, and it challenges the conventional view that trust is usually a precursor of acceptance. New conceptual models addressing these debates are described and their implications for future water-related consumer research are discussed as are potential implications for industry relationships with consumers

Selection of reference genes for gene expression analysis by real-time qPCR in avian cells infected with infectious bronchitis virus.

Infectious bronchitis virus (IBV) causes infectious bronchitis in poultry, a respiratory disease that is a source of major economic loss to the poultry industry. Detection and the study of the molecular pathogenesis of the virus often involve the use of real-time quantitative PCR assays (qPCR). To account for error within the experiments, the levels of target gene transcription are normalized to that of suitable reference genes. Despite publication of the MIQE (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) guidelines in 2009, single un-tested reference genes are often used for normalization of qPCR assays in avian research studies. Here, we use the geNorm algorithm to identify suitable reference genes in different avian cell types during infection with apathogenic and pathogenic strains of IBV. We discuss the importance of selecting an appropriate experimental sample subset for geNorm analysis, and show the effect that this selection can have on resultant reference gene selection. The effects of inappropriate normalization on the transcription pattern of a cellular signalling gene, AKT1, and the interferon-inducible, MX1, were studied. We identify the possibility of the misinterpretation of qPCR data when an inappropriate normalization strategy is employed. This is most notable when measuring the transcription of AKT1, where changes are minimal during infection

Preservice Teacher Sense-Making as They Learn to Teach Reading as Seen Through Computer-Mediated Discourse

Abstract This collective case study used methods of discourse analysis to consider what computer-mediated collaboration might reveal about preservice teachers’ sense-making in a field-based practicum as they learn to teach reading to children identified as struggling readers. Researchers agree that field-based experiences coupled with time for reflection benefit preservice teachers as they learn to teach reading. However, research is not as clear about which features of practicum experiences lead to preservice teacher learning, which may contribute to preservice teacher misconceptions, and how learning about reading instruction might be rendered more visible to researchers. Grounded in sociocultural perspectives, analysis focused on language as a mediating tool for the construction of knowledge. Data collection spanned three semesters in a literacy assessment and intervention practicum. Preservice teachers constructed understandings of readers and reading instruction through reflecting, planning, and articulating their decision-making processes with one another in the online discussion board. Findings indicated that analysis of preservice teachers’ computer-mediated discussions provided a window into their sense-making processes. While some preservice teachers’ discourse demonstrated marked growth, other preservice teachers’ limited use of precise language related to reading assessment and intervention frequently inhibited their developing understandings and instructional decisions. As well, some of the decisions instructors made likely contributed to several PST misconceptions. We conclude with implications for computer-supported collaborative environments in teacher education as a means to make preservice teacher learning more visible and accessible as a tool for teaching and learning

The Antiferromagnetic Band Structure of La2CuO4 Revisited

Using the Becke-3-LYP functional, we have performed band structure calculations on the high temperature superconductor parent compound, La2CuO4. Under the restricted spin formalism (rho(alpha) equal to rho(beta)), the R-B3LYP band structure agrees well with the standard LDA band structure. It is metallic with a single Cu x2-y2/O p(sigma) band crossing the Fermi level. Under the unrestricted spin formalism (rho(alpha) not equal to rho(beta)), the UB3LYP band structure has a spin polarized antiferromagnetic solution with a band gap of 2.0 eV, agreeing well with experiment. This state is 1.0 eV (per formula unit) lower than that calculated from the R-B3LYP. The apparent high energy of the spin restricted state is attributed to an overestimate of on-site Coulomb repulsion which is corrected in the unrestricted spin calculations. The stabilization of the total energy with spin polarization arises primarily from the stabilization of the x2-y2 band, such that the character of the eigenstates at the top of the valence band in the antiferromagnetic state becomes a strong mixture of Cu x2-y2/O p(sigma) and Cu z2/O' p(z). Since the Hohenberg-Kohn theorem requires the spin restricted and spin unrestricted calculations give exactly the same ground state energy and total density for the exact functionals, this large disparity in energy reflects the inadequacy of current functionals for describing the cuprates. This calls into question the use of band structures based on current restricted spin density functionals (including LDA) as a basis for single band theories of superconductivity in these materials.Comment: 13 pages, 8 figures, to appear in Phys. Rev. B, for more information see http://www.firstprinciples.co

Finite to infinite steady state solutions, bifurcations of an integro-differential equation

We consider a bistable integral equation which governs the stationary solutions of a convolution model of solid--solid phase transitions on a circle. We study the bifurcations of the set of the stationary solutions as the diffusion coefficient is varied to examine the transition from an infinite number of steady states to three for the continuum limit of the semi--discretised system. We show how the symmetry of the problem is responsible for the generation and stabilisation of equilibria and comment on the puzzling connection between continuity and stability that exists in this problem

T>0 properties of the infinitely repulsive Hubbard model for arbitrary number of holes

Based on representations of the symmetric group $S_N$, explicit and exact Schr\"odinger equation is derived for $U=\infty$ Hubbard model in any dimensions with arbitrary number of holes, which clearly shows that during the movement of holes the spin background of electrons plays an important role. Starting from it, at T=0 we have analyzed the behaviour of the system depending on the dimensionality and number of holes. Based on the presented formalism thermodynamic quantities have also been expressed using a loop summation technique in which the partition function is given in terms of characters of $S_N$. In case of the studied finite systems, the loop summation have been taken into account exactly up to the 14-th order in reciprocal temperature and the results were corrected in higher order based on Monte Carlo simulations. The obtained results suggest that the presented formalism increase the efficiency of the Monte Carlo simulations as well, because the spin part contribution of the background is automatically taken into account by the characters of $S_N$.Comment: 26 pages, 1 embedded ps figure; Phil. Mag. B (in press

Drift- or Fluctuation-Induced Ordering and Self-Organization in Driven Many-Particle Systems

According to empirical observations, some pattern formation phenomena in driven many-particle systems are more pronounced in the presence of a certain noise level. We investigate this phenomenon of fluctuation-driven ordering with a cellular automaton model of interactive motion in space and find an optimal noise strength, while order breaks down at high(er) fluctuation levels. Additionally, we discuss the phenomenon of noise- and drift-induced self-organization in systems that would show disorder in the absence of fluctuations. In the future, related studies may have applications to the control of many-particle systems such as the efficient separation of particles. The rather general formulation of our model in the spirit of game theory may allow to shed some light on several different kinds of noise-induced ordering phenomena observed in physical, chemical, biological, and socio-economic systems (e.g., attractive and repulsive agglomeration, or segregation).Comment: For related work see http://www.helbing.or