1,019 research outputs found

    System-Level Performance Analysis in 3D Drone Mobile Networks

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    We present a system-level analysis for drone mobile networks on a finite three-dimensional (3D) space. A performance boundary derived by deterministic random (Brownian) motion model over Nakagami-m fading interfering channels is developed. This method allows us to circumvent the extremely complex reality model and obtain the upper and lower performance bounds of actual drone mobile networks. The validity and advantages of the proposed framework are confirmed via extensive Monte-Carlo (MC) simulations. The results reveal several important trends and design guidelines for the practical deployment of drone mobile networks

    ExoMol molecular line lists V: The ro-vibrational spectra of NaCl and KCl

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    Accurate rotation-vibration line lists for two molecules, NaCl and KCl, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 3000 K). Isotopologues 23^{23}Na35^{35}Cl, 23^{23}Na37^{37}Cl, 39^{39}K35^{35}Cl, 39^{39}K37^{37}Cl, 41^{41}K35^{35}Cl and 41^{41}K37^{37}Cl are considered. Laboratory data was used to refine ab initio potential energy curves in order to compute accurate ro-vibrational energy levels. Einstein A coefficients are generated using newly determined ab initio dipole moment curves calculated using the CCSD(T) method. New Dunham Yij_{ij} constants for KCl are generated by a reanalysis of a published Fourier transform infrared emission spectra. Partition functions plus full line lists of ro-vibration transitions are made available in an electronic form as supplementary data to this article and at www.exomol.com

    Independent Sets in Restricted Line of Sight Networks

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    Line of Sight (LoS) networks were designed to model wireless networks in settings which may contain obstacles restricting visibility of sensors. A grap

    Laser decoating of DLC films for tribological applications

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    Damaged DLC coatings usually require remanufacturing of the entire coated components starting from an industrial chemical de-coating step. Alternatively, a complete or local coating repair can be considered. To pursue this approach, however, a local coating removal is needed as first operation. In this context, controlled decoating based on laser sources can be a suitable and clean alternative to achieve a pre-fixed decoating depth with high accuracy. In the present study, we investigated a laser-based decoating process executed on multilayered DLC films for advanced tribological applications (deposited via a hybrid PVD/PE-CVD technique). The results were acquired via multifocal optical digital microscopy (MF-ODM), which allowed high-resolution 3D surface reconstruction as well as digital profilometry of the lasered and unlasered surface. The study identifies the most critical process parameters which influence the effective decoating depth and the post-decoating surface roughness. In particular, the role of pulse overlap (decomposed along orthogonal directions), laser fluence, number of lasing passes and assist gas is discussed in text. A first experimental campaign was designed to identify the best conditions to obtain full decoating of the DLC + DLC:Cr layers. It was observed that decreasing the marking speed to 200 mm/s was necessary to obtain a sufficient pulse overlap and a nearly planar ablation profile. By operating with microsecond pulses and 1 J/cm2 (fairly above the ablation threshold), less than 10 passes were needed to obtain full decoating of the lasered area with an etching rate of 1.1 ÎŒm/loop. Further experiments were then executed in order to minimise the roughness of the rest surface with the best value found at around 0.2 ÎŒm. Limited oxidation but higher Ra values were observed in Ar atmosphere

    Imbibition in Disordered Media

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    The physics of liquids in porous media gives rise to many interesting phenomena, including imbibition where a viscous fluid displaces a less viscous one. Here we discuss the theoretical and experimental progress made in recent years in this field. The emphasis is on an interfacial description, akin to the focus of a statistical physics approach. Coarse-grained equations of motion have been recently presented in the literature. These contain terms that take into account the pertinent features of imbibition: non-locality and the quenched noise that arises from the random environment, fluctuations of the fluid flow and capillary forces. The theoretical progress has highlighted the presence of intrinsic length-scales that invalidate scale invariance often assumed to be present in kinetic roughening processes such as that of a two-phase boundary in liquid penetration. Another important fact is that the macroscopic fluid flow, the kinetic roughening properties, and the effective noise in the problem are all coupled. Many possible deviations from simple scaling behaviour exist, and we outline the experimental evidence. Finally, prospects for further work, both theoretical and experimental, are discussed.Comment: Review article, to appear in Advances in Physics, 53 pages LaTe

    RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

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    ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

    Coronary artery to left ventricle fistula

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    BACKGROUND: Coronary cameral fistulas are an uncommon entity, the etiology of which may be congenital or traumatic. They involve abnormal termination of a coronary artery, usually the right coronary, into a cardiac chamber, usually the right ventricle. CASE PRESENTATION: We describe a case of female patient with severe aortic stenosis and interventricular septal hypertrophy that underwent bioprosthetic aortic valve replacement with concomitant septal myectomy. On subsequent follow-up an abnormal flow traversing the septum into the left ventricle was identified and Doppler interrogation demonstrated a continuous flow, with a predominantly diastolic component, consistent with coronary arterial flow. CONCLUSION: The literature on coronary cameral fistulas is reviewed and the etiology of the diagnostic findings discussed. In our patient, a coronary artery to left ventricle fistula was the most likely explanation secondary to trauma to the septal perforator artery during myectomy. Since the patient was asymptomatic at the time of diagnosis no intervention was recommended and has done well on follow-up

    Consolidating emerging evidence surrounding HIVST and HIVSS: A rapid systematic mapping protocol

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    BACKGROUND: HIV self-testing (HIVST) is becoming popular with policy makers and commissioners globally, with a key aim of expanding access through reducing barriers to testing for individuals at risk of HIV infection. HIV self-sampling (HIVSS) was available previously to self-testing but was confined mainly to the USA and the UK. It remains to be seen whether the momentum behind HIVST will also energise efforts to expand HIVSS. Recent years have seen a rapid growth in the type of evidence related to these interventions as well as several systematic reviews. The vast majority of this evidence relates to acceptability as well as values and preferences, although new types of evidence are emerging. This systematic map aims to consolidate all emerging evidence related to HIVST and HIVSS to respond to this rapidly changing area. METHODS: We will systematically search databases and the abstracts of five conferences from 2006 to the present date, with monthly-automated database searches. Searches will combine key terms relating to HIV (e.g. HIV, AIDS, human immune-deficiency syndrome) with terms related to self-testing (e.g. home-test, self-test, mail-test, home dried blood spot test). Abstracts will be reviewed against inclusion criteria in duplicate. Data will be manually extracted through a standard form and then entered to an open access relational map (HIVST.org). When new and sufficient evidence emerges which addresses existing knowledge gaps, we will complete a review on a relevant topic. DISCUSSION: This innovative approach will allow rapid cataloguing, documenting and dissemination of new evidence and key findings as they emerge into the public domain. SYSTEMATIC REVIEW REGISTRATION: This protocol has not been registered with PROSPERO as they do not register systematic maps
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