Parasite motility is critical for virulence of African trypanosomes.

African trypanosomes, Trypanosoma brucei spp., are lethal pathogens that cause substantial human suffering and limit economic development in some of the world's most impoverished regions. The name Trypanosoma ("auger cell") derives from the parasite's distinctive motility, which is driven by a single flagellum. However, despite decades of study, a requirement for trypanosome motility in mammalian host infection has not been established. LC1 is a conserved dynein subunit required for flagellar motility. Prior studies with a conditional RNAi-based LC1 mutant, RNAi-K/R, revealed that parasites with defective motility could infect mice. However, RNAi-K/R retained residual expression of wild-type LC1 and residual motility, thus precluding definitive interpretation. To overcome these limitations, here we generate constitutive mutants in which both LC1 alleles are replaced with mutant versions. These double knock-in mutants show reduced motility compared to RNAi-K/R and are viable in culture, but are unable to maintain bloodstream infection in mice. The virulence defect is independent of infection route but dependent on an intact host immune system. By comparing different mutants, we also reveal a critical dependence on the LC1 N-terminus for motility and virulence. Our findings demonstrate that trypanosome motility is critical for establishment and maintenance of bloodstream infection, implicating dynein-dependent flagellar motility as a potential drug target

Effect of creep and shrinkage on the behavior of reinforced concrete members

Two titles published in one volume. "Creep of concrete: influencing factors and prediction" by Adam M Neville and Bernard L. Meyers and "Effect of creep and shrinkage on the behavior of reinforced concrete members" by Adrian Pauw and Bernard L. Meyers."Reprinted from Symposium on Creep of Concrete ; Publication SP-9, The American Concrete Institute.

Patients’ willingness to access cross-border healthcare

European Union (EU) Member States were required to direct their health practices to ensure implementation of ‘Directive on patients’ rights in cross-border healthcare’ which provides the right for EU citizens to seek treatment abroad. This study recruited Maltese patients, consequently it identified and quantified domains constituting willingness to access cross-border healthcare. Via this analytical approach, the results and recommendations were presented to assist cross-border healthcare policy.peer-reviewe

An Examination of Long-Term Working Memory Capacity

The purpose of this research was to explore experts’ memory capacity and the strategies experts use to achieve that capacity. Expert air traffic controllers were asked to recall traffic information during two radar and two nonradar scenarios. During radar scenarios, air traffic information was communicated aurally and displayed visually. During nonradar scenarios, air traffic information was communicated aurally only. Qualitative recall data assessment revealed an average capacity of five to eight aircraft in radar scenarios and three to six in nonradar scenarios, with two to three details recalled for most recalled aircraft. Recalled details and order of detail recall were highly consistent across experts, which suggest that aircraft details were organized and stored within larger conceptual knowledge structures. Recall patterns were additionally suggestive of frames containing slots designated for holding specific data types, structures described by Klein’s Data/Frame Model of Sensemaking. The extent of information recalled and its organization are additionally consistent with the use of long term working memory to extend working memory capacity; however, they do not rule out the use of working memory alone. Differences between radar and nonradar conditions were observed. Greater overall recall and greater and earlier recall of certain data-tag elements were observed in radar scenarios. In nonradar scenarios, greater and earlier recall of assigned actions were observed. Evaluation of experts’ descriptions of their recall processes suggested primarily visuospatial information encoding in both conditions and a lack of support for differences in the use of visuospatial or verbal encoding

Plane waves in quantum gravity: breakdown of the classical spacetime

Starting with the Hamiltonian formulation for spacetimes with two commuting spacelike Killing vectors, we construct a midisuperspace model for linearly polarized plane waves in vacuum gravity. This model has no constraints and its degrees of freedom can be interpreted as an infinite and continuous set of annihilation and creation like variables. We also consider a simplified version of the model, in which the number of modes is restricted to a discrete set. In both cases, the quantization is achieved by introducing a Fock representation. We find regularized operators to represent the metric and discuss whether the coherent states of the quantum theory are peaked around classical spacetimes. It is shown that, although the expectation value of the metric on Killing orbits coincides with a classical solution, its relative fluctuations become significant when one approaches a region where null geodesics are focused. In that region, the spacetimes described by coherent states fail to admit an approximate classical description. This result applies as well to the vacuum of the theory.Comment: 11 pages, no figures, version accepted for publication in Phys. Rev.

The Screen representation of spin networks: 2D recurrence, eigenvalue equation for 6j symbols, geometric interpretation and Hamiltonian dynamics

This paper treats 6j symbols or their orthonormal forms as a function of two variables spanning a square manifold which we call the "screen". We show that this approach gives important and interesting insight. This two dimensional perspective provides the most natural extension to exhibit the role of these discrete functions as matrix elements that appear at the very foundation of the modern theory of classical discrete orthogonal polynomials. Here we present 2D and 1D recursion relations that are useful for the direct computation of the orthonormal 6j, which we name U. We present a convention for the order of the arguments of the 6j that is based on their classical and Regge symmetries, and a detailed investigation of new geometrical aspects of the 6j symbols. Specifically we compare the geometric recursion analysis of Schulten and Gordon with the methods of this paper. The 1D recursion relation, written as a matrix diagonalization problem, permits an interpretation as a discrete Schr\"odinger-like equations and an asymptotic analysis illustrates semiclassical and classical limits in terms of Hamiltonian evolution.Comment: 14 pages,9 figures, presented at ICCSA 2013 13th International Conference on Computational Science and Applicatio

Fractional pennes' bioheat equation: Theoretical and numerical studies

Accepted for publication in Fractional calculus and applied analysisOriginally published in the journal Fract. Cal. Appl. Anal. Vol. 18 No. 4 / 2015 / pp.1080–1106 / DOI 10.1515/fca-2015-0062. The original publication is available at: http://www.degruyter.com/view/j/fca.2015.18.issue-4/fca-2015-0062/fca-2015-0062.xml?rskey=sWWcn0&result=1In this work we provide a new mathematical model for the Pennes’ bioheat equation, assuming a fractional time derivative of single order. Alternative versions of the bioheat equation are studied and discussed, to take into account the temperature-dependent variability in the tissue perfusion, and both finite and infinite speed of heat propagation. The proposed bio heat model is solved numerically using an implicit finite difference scheme that we prove to be convergent and stable. The numerical method proposed can be applied to general reaction diffusion equations, with a variable diffusion coefficient. The results obtained with the single order fractional model, are compared with the original models that use classical derivatives.The authors L.L. Ferras and J. M. Nobrega acknowledge financial funding by FEDER through the COMPETE 2020 Programme and by FCT- Portuguese Foundation for Science and Technology under the projects UID/CTM/50025/2013 and EXPL/CTM-POL/1299/2013. L.L. Ferras acknowledges financial funding by the Portuguese Foundation for Science and Technology through the scholarship SFRH/BPD/100353/2014. M. Rebelo acknowledges financial funding by the Portuguese Foundation for Science and Technology through the project UID/MAT/00297/2013