Reliability ofwood utility poles under stochastic wind load and material considering knots

Wood utility poles are simple structures used in power networks and their failure may produce a significant impact on their reliability as well as economic consequences. Wind loads are one of the main causes of damage in wood utility poles. The present study addresses the dynamic behavior of Argentinean Eucalyptus grandis wood poles with uncertain material properties under stochastic wind load. Regarding the material, the lengthwise variability of the Modulus of Elasticity (MOE) and the second moment of area are simulated through the Weak Zone (WZ) model taking into account the knots presence. The stochastic wind velocity field is derived using the Spectral Representation Method (SRM) considering temporal and spatial correlation. Then, the wind load is obtained under the considerations of the Argentinean standard CIRSOC 102. The governing equations are discretized through the Finite Element Method (FEM). The stochastic analysis is performed by means of Monte Carlo Simulations (MCS). In this study, displacements are evaluated such that a percentage of damage is found for each wind velocity. Fragility curves are a useful means to evaluate the failure probability of the poles for a defined failure mode, under a given range of demand, here the wind load. The WZ model results are compared with other MOE models previously developed (as a random variable and as a random field through the Non Gaussian Karhunen-Loève Expansion). Also, confidence bands of the fragility curves are obtained for 95% of confidence.Publicado en: Mecánica Computacional vol. XXXV, no. 21Facultad de Ingenierí

Reliability ofwood utility poles under stochastic wind load and material considering knots

Wood utility poles are simple structures used in power networks and their failure may produce a significant impact on their reliability as well as economic consequences. Wind loads are one of the main causes of damage in wood utility poles. The present study addresses the dynamic behavior of Argentinean Eucalyptus grandis wood poles with uncertain material properties under stochastic wind load. Regarding the material, the lengthwise variability of the Modulus of Elasticity (MOE) and the second moment of area are simulated through the Weak Zone (WZ) model taking into account the knots presence. The stochastic wind velocity field is derived using the Spectral Representation Method (SRM) considering temporal and spatial correlation. Then, the wind load is obtained under the considerations of the Argentinean standard CIRSOC 102. The governing equations are discretized through the Finite Element Method (FEM). The stochastic analysis is performed by means of Monte Carlo Simulations (MCS). In this study, displacements are evaluated such that a percentage of damage is found for each wind velocity. Fragility curves are a useful means to evaluate the failure probability of the poles for a defined failure mode, under a given range of demand, here the wind load. The WZ model results are compared with other MOE models previously developed (as a random variable and as a random field through the Non Gaussian Karhunen-Loève Expansion). Also, confidence bands of the fragility curves are obtained for 95% of confidence.Publicado en: Mecánica Computacional vol. XXXV, no. 21Facultad de Ingenierí

Reliability ofwood utility poles under stochastic wind load and material considering knots

Wood utility poles are simple structures used in power networks and their failure may produce a significant impact on their reliability as well as economic consequences. Wind loads are one of the main causes of damage in wood utility poles. The present study addresses the dynamic behavior of Argentinean Eucalyptus grandis wood poles with uncertain material properties under stochastic wind load. Regarding the material, the lengthwise variability of the Modulus of Elasticity (MOE) and the second moment of area are simulated through the Weak Zone (WZ) model taking into account the knots presence. The stochastic wind velocity field is derived using the Spectral Representation Method (SRM) considering temporal and spatial correlation. Then, the wind load is obtained under the considerations of the Argentinean standard CIRSOC 102. The governing equations are discretized through the Finite Element Method (FEM). The stochastic analysis is performed by means of Monte Carlo Simulations (MCS). In this study, displacements are evaluated such that a percentage of damage is found for each wind velocity. Fragility curves are a useful means to evaluate the failure probability of the poles for a defined failure mode, under a given range of demand, here the wind load. The WZ model results are compared with other MOE models previously developed (as a random variable and as a random field through the Non Gaussian Karhunen-Loève Expansion). Also, confidence bands of the fragility curves are obtained for 95% of confidence.Publicado en: Mecánica Computacional vol. XXXV, no. 21Facultad de Ingenierí

The Pioneer Anomaly

Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living Reviews in Relativit

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Evaluation of interventions on road traffic injuries in Peru: a qualitative approach

<p>Abstract</p> <p>Background</p> <p>Evaluation of interventions on road traffic injuries (RTI) going beyond the assessment of impact to include factors underlying success or failure is an important complement to standard impact evaluations. We report here how we used a qualitative approach to assess current interventions implemented to reduce RTIs in Peru.</p> <p>Methods</p> <p>We performed in-depth interviews with policymakers and technical officers involved in the implementation of RTI interventions to get their insight on design, implementation and evaluation aspects. We then conducted a workshop with key stakeholders to analyze the results of in-depth interviews, and to further discuss and identify key programmatic considerations when designing and implementing RTI interventions. We finally performed brainstorming sessions to assess potential system-wide effects of a selected intervention (Zero Tolerance), and to identify adaptation and redesign needs for this intervention.</p> <p>Results</p> <p>Key programmatic components were consistently identified that should be considered when designing and implementing RTI interventions. They include effective and sustained political commitment and planning; sufficient and sustained budget allocation; training, supervision, monitoring and evaluation of implemented policies; multisectoral participation; and strong governance and accountability. Brainstorming sessions revealed major negative effects of the selected intervention on various system building blocks.</p> <p>Conclusions</p> <p>Our approach revealed substantial caveats in current RTI interventions in Peru, and fundamental negative effects on several components of the sectors and systems involved. It also highlighted programmatic issues that should be applied to guarantee an effective implementation and evaluation of these policies. The findings from this study were discussed with key stakeholders for consideration in further designing and planning RTI control interventions in Peru.</p

The commensal bacterium Lactiplantibacillus plantarum imprints innate memory-like responses in mononuclear phagocytes

Gut microbiota is a constant source of antigens and stimuli to which the resident immune system has developed tolerance. However, the mechanisms by which mononuclear phagocytes, specifically monocytes/macrophages, cope with these usually pro-inflammatory signals are poorly understood. Here, we show that innate immune memory promotes anti-inflammatory homeostasis, using as model strains of the commensal bacterium Lactiplantibacillus plantarum. Priming of monocytes/macrophages with bacteria, especially in its live form, enhances bacterial intracellular survival and decreases the release of pro-inflammatory signals to the environment, with lower production of TNF and higher levels of IL-10. Analysis of the transcriptomic landscape of these cells shows downregulation of pathways associated with the production of reactive oxygen species (ROS) and the release of cytokines, chemokines and antimicrobial peptides. Indeed, the induction of ROS prevents memory-induced bacterial survival. In addition, there is a dysregulation in gene expression of several metabolic pathways leading to decreased glycolytic and respiratory rates in memory cells. These data support commensal microbe-specific metabolic changes in innate immune memory cells that might contribute to homeostasis in the gut.Supported by grants from the Spanish Ministry of Science, Innovation and Universities (MCIU) co-financed with FEDER funds (RTI2018-096494-B-100 to JA; BFU2016-76872-R to EB; AGL2017-86757-R to LA; SAF2015-73549-JIN to HR; SAF2016–77433-R and PID2019-110240RB-I00 to RPR). AP is supported by a Postdoctoral Fellowship from the Basque Government. DB and TMM are recipients of MCIU FPI fellowships. APC is a recipient of a fellowship from the University of the Basque Country. LA and RPR are supported by the Ramon y Cajal program from the Spanish Ministry of Economy and Competitiveness. We thank the MCIU for the Severo Ochoa Excellence accreditation (SEV-2016-0644), the Basque Department of Industry, Tourism and Trade (Etortek and Elkartek programs) and the Innovation Technology Department of the Bizkaia Province. This work was further supported by grants from the Jesús de Gangoiti Barrera Foundation.Peer reviewe

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages