Simultaneous Orthogonal Planarity

We introduce and study the $\textit{OrthoSEFE}-k$ problem: Given $k$ planar graphs each with maximum degree 4 and the same vertex set, do they admit an OrthoSEFE, that is, is there an assignment of the vertices to grid points and of the edges to paths on the grid such that the same edges in distinct graphs are assigned the same path and such that the assignment induces a planar orthogonal drawing of each of the $k$ graphs? We show that the problem is NP-complete for $k \geq 3$ even if the shared graph is a Hamiltonian cycle and has sunflower intersection and for $k \geq 2$ even if the shared graph consists of a cycle and of isolated vertices. Whereas the problem is polynomial-time solvable for $k=2$ when the union graph has maximum degree five and the shared graph is biconnected. Further, when the shared graph is biconnected and has sunflower intersection, we show that every positive instance has an OrthoSEFE with at most three bends per edge.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Formation and stabilization of multiple water-in-water-in-water (W/W/W) emulsions

Multiple Water-in-Water-in-Water (W/W/W) emulsions have been prepared, stabilized and characterized. The main objective has been to find a simple and low-cost method for the preparation of W/W/W emulsions. The system composed of gelatin, maltodextrin and water has been used, and two different methods have been studied for producing multiple emulsions in this system. In the first method, maltodextrin-in-gelatin (M/G) emulsions with small droplet size were formed by pH-induced nucleation of maltodextrin droplets, and afterwards, maltodextrinin-gelatin-in-maltodextrin (M/G/M) multiple emulsions were obtained by dispersing M/G droplets into maltodextrin solutions. The second method consisted in cooling down gelatin-inmaltodextrin (G/M) emulsions, leading to the spontaneous formation of inner maltodextrin droplets. The latter method allowed producing more homogenous M/G/M multiple emulsion droplets. The colloidal stability of such emulsions greatly improved with the addition of mucin particles, which is a glycoprotein that adsorbs on the G/M interface. Stable M/G/M multiple emulsions have been prepared and characterized by fluorescence optical microscopy, where contrast has been enhanced through covalently labelling the various components with fluorescent dyes. To our knowledge, this is the first report of a simple and cost-effective method for the production of multiple W/W/W emulsions, without using microfluidic techniques. Moreover, the present work also demonstrates that mucin microparticles can be effective stabilizers for protein-in-polysaccharide emulsions, and these dispersions can be easily prepared by phase transition methods

Use of the q-Gaussian mutation in evolutionary algorithms

Copyright @ Springer-Verlag 2010.This paper proposes the use of the q-Gaussian mutation with self-adaptation of the shape of the mutation distribution in evolutionary algorithms. The shape of the q-Gaussian mutation distribution is controlled by a real parameter q. In the proposed method, the real parameter q of the q-Gaussian mutation is encoded in the chromosome of individuals and hence is allowed to evolve during the evolutionary process. In order to test the new mutation operator, evolution strategy and evolutionary programming algorithms with self-adapted q-Gaussian mutation generated from anisotropic and isotropic distributions are presented. The theoretical analysis of the q-Gaussian mutation is also provided. In the experimental study, the q-Gaussian mutation is compared to Gaussian and Cauchy mutations in the optimization of a set of test functions. Experimental results show the efficiency of the proposed method of self-adapting the mutation distribution in evolutionary algorithms.This work was supported in part by FAPESP and CNPq in Brazil and in part by the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant EP/E060722/1 and Grant EP/E060722/2

Minimizing recombinations in consensus networks for phylogeographic studies

<p>Abstract</p> <p>Background</p> <p>We address the problem of studying recombinational variations in (human) populations. In this paper, our focus is on one computational aspect of the general task: Given two networks <it>G</it>₁and <it>G</it>₂, with both mutation and recombination events, defined on overlapping sets of extant units the objective is to compute a consensus network <it>G</it>₃with minimum number of additional recombinations. We describe a polynomial time algorithm with a guarantee that the number of computed new recombination events is within <it>ϵ </it>= <it>sz</it>(<it>G</it>₁, <it>G</it>₂) (function <it>sz </it>is a well-behaved function of the sizes and topologies of <it>G</it>₁and <it>G</it>₂) of the optimal <it>number </it>of recombinations. To date, this is the best known result for a network consensus problem.</p> <p>Results</p> <p>Although the network consensus problem can be applied to a variety of domains, here we focus on structure of human populations. With our preliminary analysis on a segment of the human Chromosome X data we are able to infer ancient recombinations, population-specific recombinations and more, which also support the widely accepted 'Out of Africa' model. These results have been verified independently using traditional manual procedures. To the best of our knowledge, this is the first recombinations-based characterization of human populations.</p> <p>Conclusion</p> <p>We show that our mathematical model identifies recombination spots in the individual haplotypes; the aggregate of these spots over a set of haplotypes defines a recombinational landscape that has enough signal to detect continental as well as population divide based on a short segment of Chromosome X. In particular, we are able to infer ancient recombinations, population-specific recombinations and more, which also support the widely accepted 'Out of Africa' model. The agreement with mutation-based analysis can be viewed as an indirect validation of our results and the model. Since the model in principle gives us more information embedded in the networks, in our future work, we plan to investigate more non-traditional questions via these structures computed by our methodology.</p

Acid sensing by the Drosophila olfactory system.

The odour of acids has a distinct quality that is perceived as sharp, pungent and often irritating. How acidity is sensed and translated into an appropriate behavioural response is poorly understood. Here we describe a functionally segregated population of olfactory sensory neurons in the fruitfly, Drosophila melanogaster, that are highly selective for acidity. These olfactory sensory neurons express IR64a, a member of the recently identified ionotropic receptor (IR) family of putative olfactory receptors. In vivo calcium imaging showed that IR64a+ neurons projecting to the DC4 glomerulus in the antennal lobe are specifically activated by acids. Flies in which the function of IR64a+ neurons or the IR64a gene is disrupted had defects in acid-evoked physiological and behavioural responses, but their responses to non-acidic odorants remained unaffected. Furthermore, artificial stimulation of IR64a+ neurons elicited avoidance responses. Taken together, these results identify cellular and molecular substrates for acid detection in the Drosophila olfactory system and support a labelled-line mode of acidity coding at the periphery

Far-infrared vibrational properties of high-pressure-high-temperature C60 polymers and the C60 dimer

We report high-resolution far-infrared transmission measurements of the 2 + 2 cycloaddition C-60 dimer and two-dimensional rhombohedral and one-dimensional orthorhombic high-pressure high-temperature C60 polymers. In the spectral region investigated(20-650 cm(-1)), we see no low-energy interball modes, but symmetry breaking of the linked C-60 balls is evident in the complex spectrum of intramolecular modes. Experimental features suggest large splittings or frequency shifts of some IhC60-derived modes that are activated by symmetry reduction, implying that the balls are strongly distorted in these structures. We have calculated the vibrations of all three systems by first-principles quantum molecular dynamics and use them to assign the predominant IhC60 symmetries of observed modes. Pur calculations show unprecedentedly large downshifts of T-1u(2)-derived modes and extremely large splittings of other modes, both of which are consistent with the experimental spectra. For the rhombohedral and orthorhombic polymers, the T-1u(2)-derived mode that is polarized along the bonding direction is calculated to downshift below any T-1u(1)-derived modes. We also identify a previously unassigned feature near 610 cm(-1) in all three systems as a widely split or shifted mode derived from various silent IhC60 vibrations, confirming a strong perturbation model for these linked fullerene structures

Comprehensive catecholaminergic projectome analysis reveals single-neuron integration of zebrafish ascending and descending dopaminergic systems

Essential components of animal behaviour are modulated by dopaminergic (DA) and noradrenergic circuitry. In this study, we reveal at cellular resolution the complete set of projections ('projectome') of every single type of DA and noradrenergio neurons in the central nervous system of zebrafish larvae. The most extensive DA projections are established by posterior tubercular otp-dependent neurons, with individual somata integrating the ascending DA system, the descending diencephalospinal, as well as the endohypothalamic circuitry. These findings suggest a major role in the modulation of physiology and behaviour for otp-dependent DA neurons, which correlate with the mammalian A11 group. We further identified an endogenous subpallial DA system that not only provides most of the local DA projections, but also connects to the ventral diencephalon. The catecholaminergic projectome map provides a framework to understand the evolution and function of these neuromodulatory systems

Relationship between inpatient satisfaction and nurse absenteeism: an exploratory study using WHO-PATH performance indicators in France

<p>Abstract</p> <p>Background</p> <p>Indicators describing results of care are widely explored in term of patient satisfaction (PS). Among factors explaining PS, human resources indicators have been studied in terms of burnout or job satisfaction among healthcare professionals. No research work has set out to explore the effect of absenteeism on PS scores. The objective of this study was to explore interaction between rate of absenteeism among nurses and PS results.</p> <p>Methods</p> <p>France has taken part in a project named PATH (Performance Assessment Tool for Hospitals) of the World Health Organization, aiming to develop a tool for the assessment of hospital performance. In the first semester 2008, 25 volunteering short-stay hospitals (teaching, general and private) provide complete data on nurse short-absenteeism (periods of up to 7 consecutive days of sick leave) and on PS (a cross-sectional postal survey using a standardized validated French-language scale EQS-H exploring "quality of medical information" (MI) and "relationships with staff and daily routine" (RS)). A multi-level model was used to take into account of the hierarchical nature of the data.</p> <p>Results</p> <p>Two thousand and sixty-five patients responded to the satisfaction questionnaire (participation rate: 40.9%). The mean age of respondents was 58 yrs (± 19), 41% were men. The mean duration of hospitalisation was 7.5 days (± 11.1). The mean absenteeism rate for nurses was 0.24% (± 0.14).</p> <p>All the PS scores were significantly and negatively correlated with rate of short-absenteeism among nurses (MI score: <it>ρ </it>= -0.55, <it>p </it>< 0.01), RS score <it>ρ </it>= -0.47, <it>p </it>= 0.02). The mixed model found a significant relationship between rate of absenteeism among nurses and PS scores (MI: <it>p </it>= 0.027; RS: <it>p </it>= 0.017).</p> <p>Conclusion</p> <p>Results obtained in this study show that short-term absenteeism among nurses seems to be significantly and negatively correlated with PS. Our findings are an invitation to deepen our understanding of the impact of human resources on PS and to develop more specific projects.</p

Smart Phone, Smart Science: How the Use of Smartphones Can Revolutionize Research in Cognitive Science

Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific “instrument” that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science

The PROgnostic Value of unrequested Information in Diagnostic Imaging (PROVIDI) Study: rationale and design

We describe the rationale for a new study examining the prognostic value of unrequested findings in diagnostic imaging. The deployment of more advanced imaging modalities in routine care means that such findings are being detected with increasing frequency. However, as the prognostic significance of many types of unrequested findings is unknown, the optimal response to such findings remains uncertain and in many cases an overly defensive approach is adopted, to the detriment of patient-care. Additionally, novel and promising image findings that are newly available on many routine scans cannot be used to improve patient care until their prognostic value is properly determined. The PROVIDI study seeks to address these issues using an innovative multi-center case-cohort study design. PROVIDI is to consist of a series of studies investigating specific, selected disease entities and clusters. Computed Tomography images from the participating hospitals are reviewed for unrequested findings. Subsequently, this data is pooled with outcome data from a central population registry. Study populations consist of patients with endpoints relevant to the (group of) disease(s) under study along with a random control sample from the cohort. This innovative design allows PROVIDI to evaluate selected unrequested image findings for their true prognostic value in a series of manageable studies. By incorporating unrequested image findings and outcomes data relevant to patients, truly meaningful conclusions about the prognostic value of unrequested and emerging image findings can be reached and used to improve patient-care