Statistical Topology of Cellular Networks in Two and Three Dimensions

Cellular networks may be found in a variety of natural contexts, from soap foams to biological tissues to grain boundaries in a polycrystal, and the characterization of these structures is therefore a subject of interest to a range of disciplines. An approach to describe the topology of a cellular network in two and three dimensions is presented. This allows for the quantification of a variety of features of the cellular network, including a quantification of topological disorder and a robust measure of the statistical similarity or difference of a set of structures. The results of this analysis are presented for numerous simulated systems including the Poisson-Voronoi and the steady-state grain growth structures in two and three dimensions

Do (and say) as I say: Linguistic adaptation in human-computer dialogs

© Theodora Koulouri, Stanislao Lauria, and Robert D. Macredie. This article has been made available through the Brunel Open Access Publishing Fund.There is strong research evidence showing that people naturally align to each other’s vocabulary, sentence structure, and acoustic features in dialog, yet little is known about how the alignment mechanism operates in the interaction between users and computer systems let alone how it may be exploited to improve the efficiency of the interaction. This article provides an account of lexical alignment in human–computer dialogs, based on empirical data collected in a simulated human–computer interaction scenario. The results indicate that alignment is present, resulting in the gradual reduction and stabilization of the vocabulary-in-use, and that it is also reciprocal. Further, the results suggest that when system and user errors occur, the development of alignment is temporarily disrupted and users tend to introduce novel words to the dialog. The results also indicate that alignment in human–computer interaction may have a strong strategic component and is used as a resource to compensate for less optimal (visually impoverished) interaction conditions. Moreover, lower alignment is associated with less successful interaction, as measured by user perceptions. The article distills the results of the study into design recommendations for human–computer dialog systems and uses them to outline a model of dialog management that supports and exploits alignment through mechanisms for in-use adaptation of the system’s grammar and lexicon

Distribution of Topological Types in Grain-Growth Microstructures

An open question in studying normal grain growth concerns the asymptotic state to which microstructures converge. In particular, the distribution of grain topologies is unknown. We introduce a thermodynamic-like theory to explain these distributions in two- and three-dimensional systems. In particular, a bending-like energy $E_i$ is associated to each grain topology $t_i$, and the probability of observing that particular topology is proportional to $\frac{1}{s(t_i)}e^{-\beta E_i}$, where $s(t_i)$ is the order of an associated symmetry group and $\beta$ is a thermodynamic-like constant. We explain the physical origins of this approach, and provide numerical evidence in support.Comment: 6 pages, 5 figure

Complete topology of cells, grains, and bubbles in three-dimensional microstructures

We introduce a general, efficient method to completely describe the topology of individual grains, bubbles, and cells in three-dimensional polycrystals, foams, and other multicellular microstructures. This approach is applied to a pair of three-dimensional microstructures that are often regarded as close analogues in the literature: one resulting from normal grain growth (mean curvature flow) and another resulting from a random Poisson-Voronoi tessellation of space. Grain growth strongly favors particular grain topologies, compared with the Poisson-Voronoi model. Moreover, the frequencies of highly symmetric grains are orders of magnitude higher in the the grain growth microstructure than they are in the Poisson-Voronoi one. Grain topology statistics provide a strong, robust differentiator of different cellular microstructures and provide hints to the processes that drive different classes of microstructure evolution.Comment: 5 pages, 6 figures, 5 supplementary page

A randomized, double-blinded trial comparing the effectiveness of tranexamic acid and epsilon-aminocaproic acid in reducing bleeding and transfusion in cardiac surgery

© 2019 Annals of Cardiac Anaesthesia. Objectives: To compare the effectiveness of epsilon aminocaproic acid (EACA) to tranexamic acid (TA) in reducing blood loss and transfusion requirements in patients undergone cardiac surgery under cardiopulmonary bypass. Design: Randomized, double blinded study. Outcome variables collected included; baseline demographic characteristics, type of surgery, amount of 24 hour chest tube drainage, amount of 24 hour blood products administered, 30 day mortality and morbidity and length of stay. We analyzed the data using parametric and non-parametric tests as appropriate. Setting: Single center tertiary-care university hospital setting. Participants: 114 patients who had undergone cardiac surgery under cardiopulmonary bypass. Interventions: Standard dose of intra-operative EACA or TA was compared in patients undergone cardiac surgery under cardiopulmonary bypass. Results: There was no statistically significant difference between groups when analyzing chest tube drainage. However, there was a significant difference in the administration of any transfusion (PRBC\u27s, FFP, platelets) intra-operatively to 24 hours postoperatively, with less transfusion in patients receiving EACA compared to TA (25% vs. 44.8%, respectively P = 0.027). Additionally, there was no significant difference in terms of adverse events during the one month follow up period. Conclusion: The findings of this study suggest that EACA and TA have similar effects on chest tube drainage but EACA is associated with fewer transfusions in CABG alone surgeries. Our results suggest that EACA can be used in a similar fashion to TA which may result in a cost and morbidity advantage

Parton distribution functions from nonlocal light-cone operators with definite twist

We introduce the chiral-even and chiral-odd quark distributions as forward matrix elements of related bilocal quark operators with well-defined (geometric) twist. Thereby, we achieve a Lorentz invariant classification of these distributions which differ from the conventional ones by explicitly taking into account the necessary trace terms. The relations between both kinds of distribution functions are given and the mismatch between their different definition of twist is discussed. Wandzura-Wilczek--like relations between the conventional distributions (based on dynamical twist) are derived by means of geometric twist distribution functions.Comment: 17 pages, REVTEX, Extended version, The Introduction has been rewritten, Setion V "Wandzura-Wilczek--like relations" and App. B are added; Sign errors are correcte

Histone deacetylase 4 interacts with 53BP1 to mediate the DNA damage response

Anumber of proteins are recruited to nuclear foci upon exposure to double-strand DNA damage, including 53BP1 and Rad51, but the precise role of these DNA damage–induced foci remain unclear. Here we show in a variety of human cell lines that histone deacetylase (HDAC) 4 is recruited to foci with kinetics similar to, and colocalizes with, 53BP1 after exposure to agents causing double-stranded DNA breaks. HDAC4 foci gradually disappeared in repair-proficient cells but persisted in repair-deficient cell lines or cells irradiated with a lethal dose, suggesting that resolution of HDAC4 foci is linked to repair. Silencing of HDAC4 via RNA interference surprisingly also decreased levels of 53BP1 protein, abrogated the DNA damage–induced G2 delay, and radiosensitized HeLa cells. Our combined results suggest that HDAC4 is a critical component of the DNA damage response pathway that acts through 53BP1 and perhaps contributes in maintaining the G2 cell cycle checkpoint