scholarly journals Impact of COVID-19 Disruptions on Global BCG Coverage and Paediatric TB Mortality: A Modelling Study

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1228
Author(s):  
Nabila Shaikh ◽  
Puck T. Pelzer ◽  
Sanne M. Thysen ◽  
Partho Roy ◽  
Rebecca C. Harris ◽  
...  
Keyword(s):  
Mitigation Measures ◽  
Bacillus Calmette Guerin ◽  
Multiple Sources ◽  
Case Scenario ◽  
Worst Case ◽  
Catch Up ◽  
Influential Variable ◽  
The Impact ◽  
Paediatric Tuberculosis ◽  
Urgent Action

The impact of COVID-19 disruptions on global Bacillus Calmette-Guérin (BCG) coverage and paediatric tuberculosis (TB) mortality is still unknown. To fill this evidence-gap and guide mitigation measures, we estimated the impact of COVID-19 disruptions on global BCG coverage and paediatric TB mortality. First, we used data from multiple sources to estimate COVID-19-disrupted BCG vaccination coverage. Second, using a static mathematical model, we estimated the number of additional paediatric TB deaths in the first 15 years of life due to delayed/missed vaccinations in 14 scenarios—varying in duration of disruption, and magnitude and timing of catch-up. We estimated a 25% reduction in global BCG coverage within the disruption period. The best-case scenario (3-month disruption, 100% catch-up within 3 months) resulted in an additional 886 (0.5%) paediatric TB deaths, and the worst-case scenario (6-month disruption with no catch-up) resulted in an additional 33,074 (17%) deaths. The magnitude of catch-up was found to be the most influential variable in minimising excess paediatric TB mortality. Our results show that ensuring catch-up vaccination of missed children is a critical priority, and delivery of BCG alongside other routine vaccines may be a feasible way to achieve catch-up. Urgent action is required to support countries with recovering vaccination coverages to minimise paediatric deaths.

scholarly journals Flattening the curve and the effect of atypical events on mitigation measures in Mexico: a modeling perspective

2020 ◽  
Author(s):  
Mario Santana-Cibrian ◽  
Manuel Adrian Acuna-Zegarra ◽  
Jorge X. Velasco-Hernandez
Keyword(s):  
Mitigation Measures ◽  
Case Scenario ◽  
Worst Case ◽  
Social Distancing ◽  
Epidemic Curve ◽  
Effective Contact ◽  
High Incidence ◽  
The Government ◽  
Mother’S Day ◽  
Short Time

On 23 and 30 March 2020 the Mexican Federal government implemented social distancing measures to mitigate the COVID-19 epidemic. We use a mathematical model to explore atypical transmission events within the confinement period, triggered by the timing and strength of short time perturbations of social distancing. We show that social distancing measures were successful in achieving a significant reduction of the effective contact rate in the early weeks of the intervention. However, "flattening the curve" had an undesirable effect, since the epidemic peak was delayed too far, almost to the government preset day for lifting restrictions (01 June 2020). If the peak indeed occurs in late May or early June, then the events of children's day and mother's day may either generate a later peak (worst case scenario), a long plateau with relatively constant but high incidence (middle case scenario) or the same peak date as in the original baseline epidemic curve, but with a post-peak interval of slower decay.

scholarly journals SPATIOTEMPORAL VISUALIZATION OF TSUNAMI WAVES USING KML ON GOOGLE EARTH

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 1291-1299 ◽  
Author(s):  
H. Mohammadi ◽  
M. R. Delavar ◽  
M. A. Sharifi ◽  
M. D. Pirooz
Keyword(s):  
Decision Making ◽  
Disaster Management ◽  
Google Earth ◽  
Disaster Mitigation ◽  
Case Scenario ◽  
Worst Case ◽  
Tsunami Waves ◽  
Spatiotemporal Visualization ◽  
Virtual Globes ◽  
The Impact

Disaster risk is a function of hazard and vulnerability. Risk is defined as the expected losses, including lives, personal injuries, property damages, and economic disruptions, due to a particular hazard for a given area and time period. Risk assessment is one of the key elements of a natural disaster management strategy as it allows for better disaster mitigation and preparation. It provides input for informed decision making, and increases risk awareness among decision makers and other stakeholders. Virtual globes such as Google Earth can be used as a visualization tool. Proper spatiotemporal graphical representations of the concerned risk significantly reduces the amount of effort to visualize the impact of the risk and improves the efficiency of the decision-making process to mitigate the impact of the risk. The spatiotemporal visualization of tsunami waves for disaster management process is an attractive topic in geosciences to assist investigation of areas at tsunami risk. In this paper, a method for coupling virtual globes with tsunami wave arrival time models is presented. In this process we have shown 2D+Time of tsunami waves for propagation and inundation of tsunami waves, both coastal line deformation, and the flooded areas. In addition, the worst case scenario of tsunami on Chabahar port derived from tsunami modelling is also presented using KML on google earth.

A Case Study - Life Extension of Offshore Bridge Bearings

2021 ◽  
Author(s):  
Ahmed Abdelkhalek ◽  
Govindavilas Sudhesh ◽  
Anjan Sarkar ◽  
Mohammed Eissa
Keyword(s):  
Cost Savings ◽  
Holistic Approach ◽  
Life Extension ◽  
Case Scenario ◽  
Worst Case ◽  
Maintenance And Repair ◽  
Seasonal Monitoring ◽  
The Impact ◽  
Bridge Bearings

Abstract Structural bearings of 47 offshore platform-link bridges with average age of 40 years were inspected and recommended for replacements due to their poor condition. Replacement of bridge bearings involves major risk and production interruptions given the structural modifications, and critical piping and E&I disconnections required for safe jacking-lifting activities required during the process. This paper presents the approach adopted to assure the integrity of the bridges and extend their lives without the need to replace the bearings. The approach employed failure mode and effect analysis to identifying and narrowing down areas that need focused efforts while tackling the problem. Scenario based structural assessments were carried out to examine the impact of the level of movement-allowing bearings functionality on the integrity of the bridge and its supporting structures; identify critical locations to be targeted during focused inspections; and establish envelopes for monitoring thermal expansion and contraction of the bridges. Guidelines were developed and implemented for integrated inspection-maintenance and repair campaign, which aimed to tackle corrosion issues and to install movement-monitoring indicators. Indicator seasonal monitoring is employed to establish the functionality of bearings on the long-term. The what-if structural assessments revealed that even in the worst-case scenario (in which the bearing are completely jammed) the option of local strengthening of the bridge and its supporting elements is more attractive than bearing replacement. The integrated inspection-maintenance and repair campaigns revealed that excessive corrosion levels observed from historic visual inspections on external non-critical bearing components (e.g: guide plates, angles, etc.) is not indicative of the condition of the internal load-bearing components (pedestals) which experienced much lower corrosion levels. The seasonal monitoring of bridge movements revealed that the 40+ years old Teflon pads are still functional and allow the bridges expansion and contraction. The developed holistic approach enabled demonstration of the fitness for service of the bearings, and provided means for assuring their long-term performance through monitoring. The results assured safety, integrity and delivered significant cost savings through aversion brownfield modifications, and production loss associated with bridge jacking and bearing replacement operations.

Quantitative Evaluation of Well Blowout Risk and Oil Spill Mitigation Measures

2021 ◽  
Author(s):  
Fabrizio Zausa ◽  
Luigi Besenzoni ◽  
Alessandro Caia ◽  
Seda Mizrak
Keyword(s):  
Risk Analysis ◽  
Oil Spill ◽  
Computational Models ◽  
Fluid Dynamic ◽  
Control Level ◽  
Mitigation Measures ◽  
Case Scenario ◽  
Worst Case ◽  
Tree Analysis ◽  
Innovative Technologies

Abstract The disaster of Macondo of 2010 changed the rules in reliability and safety standards during drilling operations. New regulations were developed in order to improve the control level on blowout risk, and all upstream operators adopted innovative technologies capable to reduce the potential risk of uncontrolled release, either by decreasing its frequency of occurrence or the expected impacts. The objective of this paper is to present a Quantitative Risk Analysis (QRA) of well blowout and measure the beneficial contribution of intervention technologies in terms of expected reduction of spill volume and associated costs. The QRA is applied to any kind of well operation (drilling, completion, workover, light intervention) and well type. The methodology relies upon different risk analysis techniques able to quantify the residual blowout risk, as well as the mitigation provided by each technology. Through Fault Tree Analysis (FTA), a value of blowout probability is calculated for each well operation. The initial blowout condition is associated with a blowout flow rate, calculated with fluid dynamic computational models depending on well flow path and release point into the environment. The evolution of each release scenario is then studied with the use of Event Tree Analysis (ETA), where a set of events, able to reduce or stop the flow, are considered with their probability of success and occurrence time (well bridging, water coning, surface intervention through killing/capping techniques, relief well operations). The value of each intervention is estimated through Decision Tree Analysis (DTA), calculating the amount of spill volume reduction and avoided spill costs. Results of spill volume and cost reduction are calculated for a set of specific wells, considering the application of killing/capping systems as well as Eni innovative technologies. The benefit of these interventions is measured in terms of Expected Monetary Value (EMV) in relation to a potential release extinguished by a relief well, which is the decisive intervention to stop the blowout, considered as the worst case scenario. Surface interventions with killing/capping techniques are the major contributors to the reduction of blowout impacts, and all additional measures which can be adopted should act in the fastest way possible before the arrival of heavy capping stack system. The main innovative contribution of the proposed QRA methodology is the association of an expected economic value to post-blowout mitigation techniques, which takes into account all possible uncertainties related to their success and intervention time. Moreover, by evaluating an economic impact of the residual spill cost, it is possible to prioritize and increase the overall efficiency of the oil spill response plan for each operational and geographical context, and improve the control on blowout risk mitigation process.

Impact of climate change on abstraction for hydropower and public water supply in Wales, UK

2021 ◽  
Author(s):  
Richard Dallison ◽  
Sopan Patil
Keyword(s):  
Climate Change ◽  
Water Supply ◽  
Hydrological Cycle ◽  
Mitigation Measures ◽  
Public Water Supply ◽  
Worst Case ◽  
Efficient Operation ◽  
Substantial Impact ◽  
Impact Of Climate Change ◽  
The Impact

<p>The impact of climate change on the hydrological cycle and catchment processes has been extensively studied. In Wales, such changes are projected to have a substantial impact on hydrological regimes. However, the impact on the water abstraction capability of key sectors in the country, such as hydropower (HP) and public water supply (PWS), is not yet fully understood. We use the Soil and Water Assessment Tool (SWAT) to generate future (2021-2054) daily streamflows under a worst-case scenario of greenhouse gas emissions (Representative Concentration Pathway 8.5) at two large catchments in Wales, the Conwy and Tywi. SWAT streamflow output is used to estimate the abstractable water resources, and therefore changes in the average generation characteristics for 25 run-of-river HP schemes across Conwy and Tywi and the total unmet demand for a single large PWS abstraction in the Tywi. This unmet PWS demand is assessed using the Water Evaluation And Planning (WEAP) system under increasing, static, and declining demand scenarios. Mann-Kendall trend analysis is performed to detect and characterise the trends for both sectors.</p><p>Results show greater seasonality in abstraction potential through the study period, with an overall decrease in annual abstraction volume due to summer and autumn streamflow declines outweighing increases seen in winter and spring. For HP, these trends result in a projected decline in annual power generation potential, despite an increasing number of days per year that maximum permitted abstraction is reached. For PWS, under all future demand scenarios, annually there is an increase in the number of days where demand is not met as well as the total shortfall volume of water. Our results suggest that currently installed HP schemes may not make optimal use of future flows, and that the planning of future schemes should take account of these to ensure the most efficient operation is achieved. Moreover, PWS supply sustainability is under threat and will require management and mitigation measures to be implemented to ensure future supplies. Overall, our study provides a novel perspective on the future water resource availability in Wales, giving context to management planning to ensure future HP generation efficiency and PWS sustainability.</p>

scholarly journals Imported dengue in Spain: a nationwide analysis with predictive time series analyses

2019 ◽  
Vol 26 (8) ◽  
Author(s):  
Lidia Redondo-Bravo ◽  
Claudia Ruiz-Huerta ◽  
Diana Gomez-Barroso ◽  
María José Sierra-Moros ◽  
Agustín Benito ◽  
...  
Keyword(s):  
Time Series ◽  
Control Measures ◽  
Severe Dengue ◽  
Vector Surveillance ◽  
Case Scenario ◽  
Worst Case ◽  
Temporal Behaviour ◽  
The Impact ◽  
Near Future ◽  
Local Transmission

Abstract Background Of febrile illnesses in Europe, dengue is second only to malaria as a cause of travellers being hospitalized. Local transmission has been reported in several European countries, including Spain. This study assesses the evolution of dengue-related admissions in Spain in terms of time, geographical distribution and individuals’ common characteristics; it also creates a predictive model to evaluate the risk of local transmission. Methods This is a retrospective study using the Hospital Discharge Records Database from 1997 to 2016. We calculated hospitalization rates and described clinical characteristics. Spatial distribution and temporal behaviour were also assessed, and a predictive time series model was created to estimate expected cases in the near future. Figures for resident foreign population, Spanish residents’ trips to endemic regions and the expansion of Aedes albopictus were also evaluated. Results A total of 588 dengue-related admissions were recorded: 49.6% were women, and the mean age was 34.3 years. One person died (0.2%), 82% presented with mild-to-moderate dengue and 7–8% with severe dengue. We observed a trend of steady and consistent increase in incidence (P < 0.05), in parallel with the increase in trips to dengue-endemic regions. Most admissions occurred during the summer, showing significant seasonality with 3-year peaks. We also found important regional differences. According to the predictive time series analysis, a continuing increase in imported dengue incidence can be expected in the near future, which, in the worst case scenario (upper 95% confidence interval), would mean an increase of 65% by 2025. Conclusion We present a nationwide study based on hospital, immigration, travel and entomological data. The constant increase in dengue-related hospitalizations, in combination with wider vector distribution, could imply a higher risk of autochthonous dengue transmission in the years to come. Strengthening the human and vector surveillance systems is a necessity, as are improvements in control measures, in the education of the general public and in fostering their collaboration in order to reduce the impact of imported dengue and to prevent the occurrence of autochthonous cases.

Assembly System Configuration Design for Reconfigurability Under Uncertain Production Evolution

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Zhengqian Jiang ◽  
Hui Wang ◽  
Maxim A. Dulebenets ◽  
Junayed Pasha
Keyword(s):  
System Throughput ◽  
Assembly System ◽  
Configuration Design ◽  
System Configuration ◽  
Case Scenario ◽  
Worst Case ◽  
Design Evolution ◽  
Product Evolution ◽  
Concurrent Optimization ◽  
The Impact

Assembly system configuration determines the topological arrangement of stations with defined logical material flow among them. The design of assembly system configuration involves (1) subassembly planning that defines subassembly tasks and between-task material flows and (2) workload balancing that determines the task-station assignments. The assembly system configuration should be flexibly changed and updated to cope with product design evolution and updating. However, the uncertainty in future product evolution poses significant challenges to the assembly system configuration design since the higher cost can be incurred if the assembly line suitable for future products is very different from that for the current products. The major challenges include (1) the estimation of reconfiguration cost, (2) unavailability of probability values for possible scenarios of product evolution, and (3) consideration of the impact of the subassembly planning on the task-station assignments. To address these challenges, this paper formulates a concurrent optimization problem to design the assembly system configuration by jointly determining the subassembly planning and task-station assignments considering uncertain product evolution. A new assembly hierarchy similarity model is proposed to estimate the reconfiguration effort by comparing the commonalities among different subassembly plans of current and potential future product designs. The assembly system configuration is chosen by maximizing both assembly hierarchy similarity and assembly system throughput under the worst-case scenario. A case study motivated by real-world scenarios demonstrates the applicability of the proposed method including scenario analysis.

The Impact of Flexbarrier Ingress on Flexlok Stress

2009 ◽  
Author(s):  
Jing Lu ◽  
Frank Ma ◽  
Zhimin Tan ◽  
Terry Sheldrake
Keyword(s):  
Internal Pressure ◽  
Structural Function ◽  
Analysis Model ◽  
Flexible Pipe ◽  
Case Scenario ◽  
Element Analysis ◽  
Worst Case ◽  
Ongoing Research ◽  
Nominal Size ◽  
The Impact

An unbonded flexible pipe typically consists of multiple metallic and thermoplastic layers, where each layer is designed to provide a specific structural function. The burst resistance against the internal pressure in an unbonded flexible pipe is provided mainly by its Flexlok layer. The Flexlok is made by helically-wound steel wires, with neighbouring wires interlocking each other. Beneath the Flexlok is the Flexbarrier, a polymer layer, acting as the boundary for conveyed fluids. The internal pressure is passed onto the Flexlok through the Flexbarrier layer. Under internal pressure, the Flexbarrier can creep into the gaps between Flexlok wires. Theoretically, the polymer material ingress could reduce the flexibility of the Flexlok due to premature lock-up between Flexlok wires and subsequently increase the stress levels. This study presents a 3D finite element analysis model developed to quantify the stress elevation in the Flexlok wire, caused by the Flexbarrier layer ingress. In terms of Flexlok gap size distribution, both nominal and worst case scenarios are studied. In the nominal scenario, the Flexlok gap sizes are evenly distributed. In the worst case scenario, the Flexlok gap is assumed to be completely closed at one position while the gaps at the neighbouring positions are twice the nominal size. Flexbarrier ingress with different temperatures is also studied. Conclusions are obtained by analyzing the simulation results. The work presented is part of an ongoing research and development project.

scholarly journals Impact of Xylella fastidiosa subspecies pauca in European olives

2020 ◽  
Vol 117 (17) ◽  
pp. 9250-9259 ◽  
Author(s):  
Kevin Schneider ◽  
Wopke van der Werf ◽  
Martina Cendoya ◽  
Monique Mourits ◽  
Juan A. Navas-Cortés ◽  
...  
Keyword(s):  
Xylella Fastidiosa ◽  
Plant Diseases ◽  
Disease Spread ◽  
Economic Damage ◽  
Climatic Suitability ◽  
Case Scenario ◽  
Worst Case ◽  
Ongoing Research ◽  
Phytosanitary Measures ◽  
The Impact

Xylella fastidiosa is the causal agent of plant diseases that cause massive economic damage. In 2013, a strain of the bacterium was, for the first time, detected in the European territory (Italy), causing the Olive Quick Decline Syndrome. We simulate future spread of the disease based on climatic-suitability modeling and radial expansion of the invaded territory. An economic model is developed to compute impact based on discounted foregone profits and losses in investment. The model projects impact for Italy, Greece, and Spain, as these countries account for around 95% of the European olive oil production. Climatic suitability modeling indicates that, depending on the suitability threshold, 95.5 to 98.9%, 99.2 to 99.8%, and 84.6 to 99.1% of the national areas of production fall into suitable territory in Italy, Greece, and Spain, respectively. For Italy, across the considered rates of radial range expansion the potential economic impact over 50 y ranges from 1.9 billion to 5.2 billion Euros for the economic worst-case scenario, in which production ceases after orchards die off. If replanting with resistant varieties is feasible, the impact ranges from 0.6 billion to 1.6 billion Euros. Depending on whether replanting is feasible, between 0.5 billion and 1.3 billion Euros can be saved over the course of 50 y if disease spread is reduced from 5.18 to 1.1 km per year. The analysis stresses the necessity to strengthen the ongoing research on cultivar resistance traits and application of phytosanitary measures, including vector control and inoculum suppression, by removing host plants.

scholarly journals Lossless WDM PON Photonic Integrated Receivers Including SOAs

2019 ◽  
Vol 9 (12) ◽  
pp. 2457 ◽  
Author(s):  
Goki ◽  
Imran ◽  
Porzi ◽  
Toccafondo ◽  
Fresi ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Wavelength Division Multiplexing ◽  
Flip Chip ◽  
Optical Network ◽  
Silicon On Insulator ◽  
Passive Optical Network ◽  
Case Scenario ◽  
Worst Case ◽  
The Impact ◽  
Wdm Transmission

The role of a semiconductor optical amplifier (SOA) for amplifying downstream traffic at optical network terminals (ONT) within a silicon-photonics integrated receiver in a high capacity passive optical network (PON) is investigated. The nearly traveling wave SOA effects are evaluated by considering fabrication and link loss constraints through numerical analysis and experimental validation. The impact of hybrid integration of a SOA chip on a silicon on insulator (SOI) photonic chip using the flip chip bonding technique on SOA design is evaluated through numerical analysis of a multi section cavity model. The performance of the proposed ONT receiver design employing twin parallel SOAs is evaluated experimentally on a 32 × 25 Gb/s OOK WDM transmission system considering cross gain modulation (XGM) and amplified spontaneous emission (ASE) constraints. The XGM impact is evaluated through 32 channel wavelength division multiplexing (WDM) transmission and a likely PON worst case scenario of high channel power difference (~10 dB) between adjacent channels. The impact of ASE is evaluated through the worst-case polarization condition, i.e., when all of the signal is coupled to only one. Successful transmission was achieved in both worst-case conditions with limited impact on performance. SOA results indicate that a maximum residual facet reflectivity of 4 × 10−4 for the chip-bonded device can lead to a power penalty below 2 dB in a polarization-diversity twin SOAs receiver.

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