1,625 research outputs found

    Hydrodynamic modeling of partial dikes

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    International audienceDue to lack of space, the city of Monaco has extended over the sea, by land reclaiming. The bordering waterdepths are now so deep that the city has been considering building housings set on jacket types of struc tures. These constructions would have to be protected from sea waves, by so-called "partial dikes". An example of such partial dikes is the BYBOP caisson that was installed recently at the mouth of Port Hercule. Its shape was optimized through systematic model tests. Quite noticeable are the slanted parts that protrude both on the up-wave and down-wave sides. The appendix on the lee-side was found to have quite a strong effect on the reduction of the transmission coeffcient

    Spectrums of Black Hole in de Sitter Spacetime with Highly Damped Quasinormal Modes: High Overtone Case

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    Motivated by recent physical interpretation on quasinormal modes presented by Maggiore, the adiabatic quantity method given by Kunstatter is used to calculate the spectrums of a non-extremal Schwarzschild de Sitter black hole in this paper, as well as electrically charged case. According to highly damped Konoplya and Zhidenko's numerical observational results for high overtone modes\cite{Konoplya}, we found that the asymptotic non-flat spacetime structure leads two interesting facts as followings: (i) near inner event horizon, the area and entropy spectrums, which are given by Aen=8n1πA_{en} = 8 n_1 \pi \hbar, Sen=2πn1S_{en} = 2\pi n_1\hbar, are equally spaced accurately. (ii) However, near outer cosmological horizon the spectrums, which are in the form of Acn=16n2π48πΛAcn3Acn2A_{cn} = 16 n_2 \pi \hbar - \sqrt{\frac{48\pi}{\Lambda}A_{cn} - 3 A_{cn}^2}, Scn=4πn23πΛAcn3/16Acn2S_{cn} = 4 \pi n_2 \hbar - \sqrt{\frac{3\pi}{\Lambda}A_{cn} - 3/16 A_{cn}^2}, are not markedly equidistant. Finally, we also discuss the electrically charged case and find the black holes in de Sitter spacetime have similar quantization behavior no matter with or without charge.Comment: 12 pages, 2 firures, published versio

    Energy-Based Interference Analysis of Heterogeneous Packet Radio Networks

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    Modelling travel time reliability in public transport route choice behaviour

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    The implementation of travel time reliability (TTR) in route choice behaviour is still not very common in transport models, especially not in a public transport context. The reasons probably are that it is difficult to measure and that there is no agreement how it best can be represented in utility functions. Typically, it is represented by a standard deviation, however, particularly in public transport choices it is more likely that travellers think about the consequences of unreliability in travel times in terms of buffer times. This paper contributes to the literature by comparing five different model specifications of TTR in public transport route choices that are either based on standard deviations or on buffer time indicators. The models are estimated from choices observed in a stated choice experiment. To address heterogeneity, a latent class model is estimated. The results suggest that the reliability buffer time indicator outperforms the standard deviation indicator. Furthermore, the reliability buffer time parameter is only statistically significant in two of the four classes. The other two classes are particularly sensitive to making transfers and to low frequencies of public transport services, suggesting different strategies to deal with TTR

    Time variable cosmological constant of holographic origin with interaction in Brans-Dicke theory

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    Time variable cosmological constant (TVCC) of holographic origin with interaction in Brans-Dicke theory is discussed in this paper. We investigate some characters for this model, and show the evolutions of deceleration parameter and equation of state (EOS) for dark energy. It is shown that in this scenario an accelerating universe can be obtained and the evolution of EOS for dark energy can cross over the boundary of phantom divide. In addition, a geometrical diagnostic method, jerk parameter is applied to this model to distinguish it with cosmological constant.Comment: 10 pages, 9 figure

    Molecular characterization of ‘Candidatus Phytoplasma mali’ strains in outbreaks of apple proliferation in north eastern Italy, Hungary, and Serbia

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    During 2005-2008 apple plants of different varieties showing proliferation symptoms were observed in diverse areas of north eastern Italy, Hungary and Serbia. PCR/RFLP analyses showed that all the samples were infected with ‘Candidatus Phytoplasma mali’. In the 16S plus spacer region two phytoplasma profiles (P-I and P-II) were distinguished. P-I profile was detected in reference strains AP, AT1, AT2, in samples from Serbia, and in the majority of samples from Trentino; the P-II profile was prevalent in samples from Veneto; both profiles were identified in samples from Hungary, in some cases together in single samples. The analyses of rpl22-s3 genes allow the identification, in all the samples showing a P-I profile, the presence of phytoplasmas belonging to rpX-A subgroup, while in the samples showing a P-II profile it was possible to distinguish the other three reported rpX subgroups. In the majority of samples from the Veneto region phytoplasmas belonging to rpX-D subgroup were identified, while rpX-B and rpX-C subgroups were identified only in a few samples from Trentino and Veneto regions, respectively. Further RFLP analyses on AP13/AP10 amplicons differentiate among strains belonging to the rpX-A subgroup: the samples from Serbia show AP profiles, while those from Trentino show AT-2 profiles. In the samples from Hungary the presence of AT1, AT2, and AP profiles was identified.Keywords: Apple, ‘Candidatus Phytoplasma mali’, phytoplasma strains, PCR/RFLP analyses, epidemiolog

    Diversity, Prevalence, and Longitudinal Occurrence of Type II Toxin-Antitoxin Systems of Pseudomonas aeruginosa Infecting Cystic Fibrosis Lungs

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    Type II toxin-antitoxin (TA) systems are most commonly composed of two genes encoding a stable toxin, which harms the cell, and an unstable antitoxin that can inactivate it. TA systems were initially characterized as selfish elements, but have recently gained attention for regulating general stress responses responsible for pathogen virulence, formation of drug-tolerant persister cells and biofilms—all implicated in causing recalcitrant chronic infections. We use a bioinformatics approach to explore the distribution and evolution of type II TA loci of the opportunistic pathogen, Pseudomonas aeruginosa, across longitudinally sampled isolates from cystic fibrosis lungs. We identify their location in the genome, mutations, and gain/loss during infection to elucidate their function(s) in stabilizing selfish elements and pathogenesis. We found (1) 26 distinct TA systems, where all isolates harbor four in their core genome and a variable number of the remaining 22 on genomic islands; (2) limited mutations in core genome TA loci, suggesting they are not under negative selection; (3) no evidence for horizontal transmission of elements with TA systems between clone types within patients, despite their ability to mobilize; (4) no gain and limited loss of TA-bearing genomic islands, and of those elements partially lost, the remnant regions carry the TA systems supporting their role in genomic stabilization; (5) no significant correlation between frequency of TA systems and strain ability to establish as chronic infection, but those with a particular TA, are more successful in establishing a chronic infection

    Barriers and facilitators to the implementation of nurse’s role in primary care settings: an integrative review

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    Background: The rapid evolution of the epidemiological picture and the recent SARS-COV-2 pandemic has expressed the vulnerabilities of health systems and focuses attention on the population’s needs. The nurse’s figure in the care teams is universally identified; however, the implementation of the role within some care settings turns out to be complex and challenging. This integrative review aims to identify the barriers and facilitators in implementing the role of the nurse in primary care settings. Methods: An integrative review was conducted on the Medline and Cinahl databases until 9 June 2020. Qualitative, quantitative, and Mixed-method research studies were selected to identify studies related to the barriers and facilitators of the nurse’s role in nursing facilities’ primary care. For the extraction of the results, the Consolidating Framework for Research Implementation (CFIR) was used to identify the factors that influence implementation in health care. Results: Following the duplicates’ removal, the search identified 18,257 articles, of which 56 were relevant to the inclusion criteria; therefore, they were included in the summary. The selected studies were conducted in thirteen countries, most from Oceania, Europe, North America, Latin America, and the Caribbean. The barriers reported most frequently concern the nursing profession’s regulatory and regulatory aspects within the contexts of care, cultural and organizational aspects, training, and the transfer of specific skills, which were previously designated to doctors. The facilitators are mainly linked to the nurse’s adaptability to the various contexts of care, recognizing the patient’s role, and the desire to develop multidisciplinary and effective working groups to respond to the health needs of the population in primary care contexts. Conclusion: This review highlighted the main barriers and facilitators in implementing the nurse’s role in primary care settings. These results offer useful elements for stakeholders to identify effective strategies in preparing programs and activities for implementing the nurse’s role, acting on the elements identified as barriers and favouring the aspects that emerge as facilitators

    Isolation and characterisation of the first microsatellite markers for \u3ci\u3eCyperus rotundus\u3c/i\u3e

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    This is the first report of microsatellite markers for Cyperus rotundus. A total of 191 sequence-specific microsatellite markers were isolated and used to screen12 accessions of C. rotundus and one accession of Cyperus esculentus collected from 10 different countries. Polymorphisms were observed in 49% of the markers tested, 22% of the markers were monomorphic and 29% had weak or no amplification. The best 57 markers are reported, and cluster analysis was used to analyse their resolving power. BLASTx screening of the contig sequences was also performed. Multiallelic loci over all samples ranged from 24% to 60%. The maximum number of alleles detected by the markers suggests a polyploidy nature of all C. rotundus accessions tested, except for the sample N25-Brazil. Chromosome number was determined for N12-Taiwan and used as an internal flow cytometry standard to estimate the amount of DNA within haploid nuclei of the remaining material. Chromosome numbers estimated for C. rotundus were 16 and 24. The markers identified in this study can be used for the identification of biotypes and detection of potential crosses of C. rotundus, to implement management practices for the effective control of this weed
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