69,753,265 research outputs found

    Characterization of water and wildlife strains as a subgroup of Campylobacter jejuni using DNA microarrays.

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    Campylobacter jejuni is the leading cause of human bacterial gastroenteritis worldwide, but source attribution of the organism is difficult. Previously, DNA microarrays were used to investigate isolate source, which suggested a non-livestock source of infection. In this study we analysed the genome content of 162 clinical, livestock and water and wildlife (WW) associated isolates combined with the previous study. Isolates were grouped by genotypes into nine clusters (C1 to C9). Multilocus sequence typing (MLST) data demonstrated that livestock associated clonal complexes dominated clusters C1-C6. The majority of WW isolates were present in the C9 cluster. Analysis of previously reported genomic variable regions demonstrated that these regions were linked to specific clusters. Two novel variable regions were identified. A six gene multiplex PCR (mPCR) assay, designed to effectively differentiated strains into clusters, was validated with 30 isolates. A further five WW isolates were tested by mPCR and were assigned to the C7-C9 group of clusters. The predictive mPCR test could be used to indicate if a clinical case has come from domesticated or WW sources. Our findings provide further evidence that WW C. jejuni subtypes show niche adaptation and may be important in causing human infection

    Discovering the roots: Uniform closure results for algebraic classes under factoring

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    Newton iteration (NI) is an almost 350 years old recursive formula that approximates a simple root of a polynomial quite rapidly. We generalize it to a matrix recurrence (allRootsNI) that approximates all the roots simultaneously. In this form, the process yields a better circuit complexity in the case when the number of roots rr is small but the multiplicities are exponentially large. Our method sets up a linear system in rr unknowns and iteratively builds the roots as formal power series. For an algebraic circuit f(x1,,xn)f(x_1,\ldots,x_n) of size ss we prove that each factor has size at most a polynomial in: ss and the degree of the squarefree part of ff. Consequently, if f1f_1 is a 2Ω(n)2^{\Omega(n)}-hard polynomial then any nonzero multiple ifiei\prod_{i} f_i^{e_i} is equally hard for arbitrary positive eie_i's, assuming that ideg(fi)\sum_i \text{deg}(f_i) is at most 2O(n)2^{O(n)}. It is an old open question whether the class of poly(nn)-sized formulas (resp. algebraic branching programs) is closed under factoring. We show that given a polynomial ff of degree nO(1)n^{O(1)} and formula (resp. ABP) size nO(logn)n^{O(\log n)} we can find a similar size formula (resp. ABP) factor in randomized poly(nlognn^{\log n})-time. Consequently, if determinant requires nΩ(logn)n^{\Omega(\log n)} size formula, then the same can be said about any of its nonzero multiples. As part of our proofs, we identify a new property of multivariate polynomial factorization. We show that under a random linear transformation τ\tau, f(τx)f(\tau\overline{x}) completely factors via power series roots. Moreover, the factorization adapts well to circuit complexity analysis. This with allRootsNI are the techniques that help us make progress towards the old open problems, supplementing the large body of classical results and concepts in algebraic circuit factorization (eg. Zassenhaus, J.NT 1969, Kaltofen, STOC 1985-7 \& Burgisser, FOCS 2001).Comment: 33 Pages, No figure

    Electronic, vibrational and magnetic properties of a novel C_{48}N_{12} aza-fullerene

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    We study the structural, electronic, vibrational and magnetic properties of a novel C48N12{\rm C}_{48}{\rm N}_{12} aza-fullerene using density functional theory and restricted Hartree-Fock theory. Optimized geometries and total energy of this fullerene have been calculated. We find that for C48N12{\rm C}_{48}{\rm N}_{12} the total ground state energy is about -67617 eV, the HOMO-LUMO gap is about 1.9 eV, five strong IR spectral lines are located at the vibrational frequencies, 461.5 cm1{\rm cm}^{-1}, 568.4 cm1{\rm cm}^{-1}, 579.3 cm1{\rm cm}^{-1}, 1236.1 cm1{\rm cm}^{-1}, 1338.9 cm1{\rm cm}^{-1}, the Raman scattering activities and depolarization ratios are zero, and 10 NMR spectral signals are predicted. Calculations of diamagnetic shielding factor, static dipole polarizabilities and hyperpolarizabilities of C48N12{\rm C}_{48}{\rm N}_{12} are performed and discussed.Comment: published in Chem.Phys.Let

    Dilution of seawater affects the Ca2 + transport in the outer mantle epithelium of crassostrea gigas

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    Varying salinities of coastal waters are likely to affect the physiology and ion transport capabilities of calcifying marine organisms such as bivalves. To investigate the physiological effect of decreased environmental salinity in bivalves, adult oysters (Crassostrea gigas) were exposed for 14 days to 50% seawater (14) and the effects on mantle ion transport, electrophysiology and the expression of Ca2+ transporters and channels relative to animals maintained in full strength sea water (28) was evaluated. Exposure of oysters to a salinity of 14 decreased the active mantle transepithelial ion transport and specifically affected Ca2+ transfer. Gene expression of the Na+/K+-ATPase and the sarco(endo)plasmic reticulum Ca2+-ATPase was decreased whereas the expression of the T-type voltage-gated Ca channel and the Na+/Ca2+-exchanger increased compared to animals maintained in full SW. The results indicate that decreased environmental salinities will most likely affect not only osmoregulation but also bivalve biomineralization and shell formation.Funding Agency European Union (EU) 605051 Swedish Mariculture Research Center, SWEMARC, University of Gothenburg Herbert & Karin Jacobssons Stiftelse 15/h17 Helge Ax:son Johnsons Stiftelse F18-0128 Portuguese Foundation for Science and Technology UID/Multi/04326/2019 Portuguese Foundation for Science and Technology UID/Multi/04326/2019 FCT, under the "Norma Transitoria" DL57/2016/CP1361/CT0020 DL57/2016/CP1361/CT0011info:eu-repo/semantics/publishedVersio

    Auto-transcendance: l'expérience de l'accompagnement des personnes en fin de vie, la réalité pour l'infirmière : travail de Bachelor

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    Thème : Notre recherche traite du rapport de l’infirmière à la mort du patient et les conséquences pour l’accompagnement professionnel au cours de cette ultime phase de la vie. Contenu : L’allongement de l’espérance de vie avec, comme corollaire, le vieillissement de la population est un des faits marquants de ces dernières décennies. En conséquence, les structures d’accueil en soins palliatifs sont en rapide développement et le rôle du personnel soignant fait l’objet d’une réflexion et d’un questionnement de plus en plus poussé sur le sens de son action et de sa mission. Pour aborder cette problématique, nous avons recouru à la recension des articles publiés entre 2005 et 2014, tirés exclusivement de bases de données médicales scientifiques et focalisés sur les différentes attitudes des infirmières qui accompagnent les personnes en fin de vie. Par la suite, notre analyse s’appuie sur la théorie de Reed et des notions de vulnérabilité, d’auto-transcendance et de bienêtre qu’elle met en avant. Ainsi s’est confirmé et précisé pour nous non seulement le rôle primordial que joue la relation dans l’action du soignant auprès du soigné et dans la qualité des soins donnés, mais aussi l’importance du vécu de l’infirmière qui gère ces situations de fin de vie. Conclusion : Cette revue de littérature a mis en lumière, en premier lieu, le retentissement de la proximité de la mort des patients sur la pratique infirmière. Elle a fait également apparaître le rôle constructif que peut jouer la relation au patient mourant dans le développement personnel et professionnel de la soignante. En contrepartie, il s’avère indispensable que tous les soignants reçoivent une formation bien adaptée, qui renforce les ressources personnelles – tant psychologiques et morales que spirituelles – qui sont nécessaires pour leur équilibre et leur épanouissement personnel, pour la qualité des soins palliatifs qu’ils prodiguent aux personnes en fin de vie et pour l’accompagnement des familles
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