795 research outputs found

    Optimal Content Placement in ICN Vehicular Networks

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    Information Centric Networking (ICN) is a networking framework for content distribution. The communication is based on a request/response model where the attention is centered on the content. The user sends interest messages naming the content it desires and the network chooses the best node from which delivers the content. This way for retrieving contents naturally fits a context where users continuously change their location. One of the main problems of user mobility is the intermittent connectivity that causes loss of packets. This work shows how in a Vehicle-to-Infrastructure scenario, the network can exploit the ICN architecture with content pre-distribution to maximize the probability that the user retrieves the desired content. We give an ILP formulation of the problem of optimally distributing the contents in the network nodes and discuss how the system assumptions impact the success probability. Moreover, we validate our model by means of simulations with ndnSIM

    Exact Constructions in the (Non-linear) Planar Theory of Elasticity: From Elastic Crystals to Nematic Elastomers

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    In this article we deduce necessary and sufficient conditions for the presence of “Conti-type”, highly symmetric, exactly stress-free constructions in the geometrically non-linear, planar n-well problem, generalising results of Conti et al. (Proc R Soc A 73(2203):20170235, 2017). Passing to the limit nn\rightarrow\infty, this allows us to treat solid crystals and nematic elastomer differential inclusions simultaneously. In particular, we recover and generalise (non-linear) planar tripole star type deformations which were experimentally observed in Kitano and Kifune (Ultramicroscopy 39(1–4):279–286, 1991), Manolikas and Amelinckx (Physica Status Solidi (A) 60(2):607–617, 1980; Physica Status Solidi (A) 61(1):179–188, 1980). Furthermore, we discuss the corresponding geometrically linearised problem

    Unraveling the effect of proliferative stress in vivo in hematopoietic stem cell gene therapy mouse study

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    The hematopoietic system of patients enrolled in hematopoietic stem cells (HSC) gene therapy (GT) treatments is fully reconstituted upon autologous transplantation of engineered stem cells. HSCs highly proliferate up to full restoration of homeostasis and compete for niche homing and engraftment. The impact of the proliferation stress in HSC on genetic instability remains an open question that cured patients advocate for characterizing long-term safety and efficacy. The accumulation of somatic mutations has been widely used as a sensor of proliferative stress. Vector integration site (IS) can be used as a molecular tool for clonal identity, inherited by all HSC progeny, to uncover lineage dynamics in vivo at single-cell level. Here we characterized at single-clone granularity the proliferative stress of HSCs and their progeny over time by measuring the accumulation of mutations from the DNA of each IS. To test the feasibility of the approach, we set-up an experimental framework that combines tumor-prone Cdkn2a-/- and wild type (WT) mouse models of HSC-GT and molecular analyses on different hematopoietic cell lineages after transplantation of HSCs transduced with genotoxic LV (LV.SF.LTR) or GT-like non-genotoxic LV (SIN.LV.PGK). The Cdkn2a-/- mouse model provided the experimental conditions to detect the accumulation of somatic mutations, since the absence of p16INK4A and p19ARF enhances the proliferative potential of cells that have acquired oncogenic mutations. As expected, mice transplanted with Cdkn2a-/- Lin- cells marked with LV.SF.LTR (N=24) developed tumors significantly earlier compared to mock (N=20, p<0.0001), while mice treated with SIN. LV.PGK (N=23) did not. On the other side, mice that received WT Lin- cells treated with LV.SF.LTR (N=25) or SIN.LV.PGK (N=24) vector have not developed tumors. Given this scenario, we expect that Cdkn2a-/- Lin- cells transduced with LV.SF.LTR are associated with higher mutation rates compared to the SIN.LV.PGK group and wild type control mice. The composition of peripheral blood, lymphoid (B and T) and myeloid compartments was assessed by FACS on samples collected every 4 weeks and IS identification. More than 200,000 IS have been recovered. To identify the presence of somatic mutations, the genomic portions of sequencing reads flanking each different IS were analyzed with VarScan2. The accumulation rates of mutations have been evaluated by our new Mutation Index (MI) which normalizes the number of mutations by clones and coverage. Considering that a large portion of IS has been discarded since not covered by a minimum number of 5 unique reads (genomes), the remaining number of IS contained >90% of reads in each group. The MI increased over time in both LV.SF.LTR groups, with higher values for the Cdkn2a-/-. On the other hand, treatment with SIN.LV.PGK resulted in lower MI in both groups compared to LV.SF.LTR groups, reflecting the higher clonal composition of the cells treated with the SIN.LV.PGK and the phenomenon of insertional mutagenesis in the LV.SF.LTR. Moreover, the higher MI values of the SIN.LV.PGK Cdkn2a-/- group compared with the WT group proved the induction of DNA fragility. Our results showed that the analysis of the accumulation of somatic mutations at single clone unraveled HSC proliferation stress in vivo, combining for the first time the analysis of acquired mutations with IS. We are now applying our model to different clinical trials, and studying HSCs sub- clonal trees by symmetric divisions, previously indistinguishable by IS only. Our study will open the doors to in vivo long-term non-invasive studies of HSC stability in patients

    The association between air pollution and the incidence of idiopathic pulmonary fibrosis in Northern Italy

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    Acute exacerbations and worsening of idiopathic pulmonary fibrosis (IPF) have been associated with exposure to ozone (O3), nitrogen dioxide (NO2) and particulate matter, but chronic exposure to air pollution might also affect the incidence of IPF. We investigated the association between chronic exposure to NO2, O3 and particulate matter with an aerodynamic diameter <10 \u3bcm (PM10) and IPF incidence in Northern Italy between 2005 and 2010. Daily predictions of PM10 concentrations were obtained from spatiotemporal models, and NO2 and O3 hourly concentrations from fixed monitoring stations. We identified areas with homogenous exposure to each pollutant. We built negative binomial models to assess the association between area-specific IPF incidence rate, estimated through administrative databases, and average overall and seasonal PM10, NO2, and 8-hour maximum O3 concentrations. Using unadjusted models, an increment of 10 \u3bcg\ub7m-3 in NO2 concentration was associated with an increase between 7.93% (95% CI 0.36-16.08%) and 8.41% (95% CI -0.23-17.80%) in IPF incidence rate, depending on the season. After adjustment for potential confounders, estimated effects were similar in magnitude, but with larger confidence intervals. Although confirmatory studies are needed, our results trace a potential association between exposure to traffic pollution and the development of IPF

    Health-related quality of life burden in scleroderma patients treated with two different intravenous iloprost regimens

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    Systemic sclerosis (SSc)-related Raynaud's phenomenon (RP) and digital ulcers (DU) can impair health-related quality of life (HRQoL). The aim of our study was to estimate HRQoL in SSc patients treated with two different intravenous (IV) iloprost (ILO) regimens and in patients not treated with IV ILO. 96 consecutive SSc patients were enrolled in a pragmatic, prospective and non-randomized study, and divided into 3 groups: not requiring therapy with IV ILO (N=52), IV ILO once monthly (N=24) or IV ILO for 5 consecutive days every 3 months (N=20). Patients were followed up for three months. We assessed HRQoL using the generic preference-based questionnaire EQ-5D-5L. We conducted multiple regression analyses to estimate, in each treatment group, the mean general health (GH) and the mean utility index of the EQ-5D-5L, adjusting for possible confounders. The mean adjusted utility index and GH score, after three months' follow-up, were not different in the three groups: IV ILO was able to make patients requiring IV ILO similar to those not requiring it. Moreover, there was no difference in this model between the two ILO regimens (1 day monthly vs 5 consecutive days every 3 months). The two different IV ILO regimens (the most appropriate regimen was decided according to patients' characteristics and needs) were able to stabilize HRQoL in RP secondary to SSc non-adequately controlled by oral therapy

    Post-graduate medical education in public health: The case of Italy and a call for action

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    Public health technical expertise is of crucial importance to inform decision makers\u2019 action in the field of health and its broader determinants. Improving education and training of public health professionals for both practice and research is the starting point to strengthen the role of public health so that current health challenges can be efficiently tackled. At the Association of Schools of Public Health in the European Region (ASPHER) Deans\u2019 & Directors\u2019 2017 Annual Retreat, we presented the structure and management of public health training system in Italy, and we reported recent data on Italian public health specialists\u2019 educational experience, employment opportunities and job satisfaction. Public health training in Italy is implemented in the context of the post-graduate medical education residency programme in Hygiene and Preventive Medicine, delivered by 34 University-based Schools of Public Health. We report relatively high employment rates across the county and wide spectrum of career opportunities for young public health specialists. However, job security is low and training expectations only partially met. We call upon other Schools of Public Health to scale up the survey within the broad ASPHER community in a shared and coordinated action of systematically collecting useful data that can inform the development of public health education and training models, their implementation and fruitful interaction with population health, health systems and services
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