Testing the convergence hypothesis: a longitudinal and cross-sectional analysis of the world trade web through social network and statistical analyses

Author(s):  
Lucio Biggiero ◽  
Roberto Urbani
2021 ◽  
Author(s):  
Taha Saleem

Road traffic crashes are one of the major causes of deaths and injuries around the world killing approximately 1.2 million people and injuring over 50 million every year. One of the primary goals of transportation agencies around the world is to reduce crashes as well as minimize the potential for human error and provide a forgiving road environment. Estimating the safety effects of highway design and operational elements is essential in achieving this goal. This research is divided into two components aimed at advancing the methodology for estimating these effects. The first component looks at evaluating the potential of cross-sectional analysis for developing crash modification factors/functions (CMFs/CMFunctions) used to represent the effects of safety treatments on crashes. First, the cross-sectional approach was used to investigate the safety effects of horizontal curvature on rural two-lane highways, which would be impossible to evaluate with before-after data. Second, this approach was further evaluated using databases of sites that were actually treated and similar, but untreated reference sites. The treatment databases for this part consisted of combination rumble strips (center line plus shoulder), wet reflective pavement markings and intersection conflict warning systems. The results from the cross-sectional analysis were then compared to recent studies where empirical Bayes before-after analysis was conducted with the same dataset used for the cross-sectional analysis. The results were promising in that the effects from the cross-sectional and before-after studies were reasonably comparable in each case. In addition, it was possible in some cases to relate the CMF to application circumstances by developing CMFunctions, providing results that could not be achieved in the before-after studies. The second component of this research involved development of roundabout crash predictions using conflicting volumes and delays, which could only be estimated from turning movement counts that are rarely collected at roundabouts. The object was to determine whether the considerable extra effort to collect these data would be worthwhile. The developed models were compared to the traditional models based on approach flows. The results suggest that collecting turning movement data, which is also required for capacity analysis, would be worthwhile for evaluating roundabout safety.


BMJ ◽  
2020 ◽  
pp. m4750 ◽  
Author(s):  
Anthony D So ◽  
Joshua Woo

AbstractObjectiveTo analyze the premarket purchase commitments for coronavirus disease 2019 (covid-19) vaccines from leading manufacturers to recipient countries.DesignCross sectional analysis.Data sourcesWorld Health Organization’s draft landscape of covid-19 candidate vaccines, along with company disclosures to the US Securities and Exchange Commission, company and foundation press releases, government press releases, and media reports.Eligibility criteria and data analysisPremarket purchase commitments for covid-19 vaccines, publicly announced by 15 November 2020.Main outcome measuresPremarket purchase commitments for covid-19 vaccine candidates and price per course, vaccine platform, and stage of research and development, as well as procurement agent and recipient country.ResultsAs of 15 November 2020, several countries have made premarket purchase commitments totaling 7.48 billion doses, or 3.76 billion courses, of covid-19 vaccines from 13 vaccine manufacturers. Just over half (51%) of these doses will go to high income countries, which represent 14% of the world’s population. The US has reserved 800 million doses but accounts for a fifth of all covid-19 cases globally (11.02 million cases), whereas Japan, Australia, and Canada have collectively reserved more than one billion doses but do not account for even 1% of current global covid-19 cases globally (0.45 million cases). If these vaccine candidates were all successfully scaled, the total projected manufacturing capacity would be 5.96 billion courses by the end of 2021. Up to 40% (or 2.34 billion) of vaccine courses from these manufacturers might potentially remain for low and middle income countries–less if high income countries exercise scale-up options and more if high income countries share what they have procured. Prices for these vaccines vary by more than 10-fold, from $6.00 (£4.50; €4.90) per course to as high as $74 per course. With broad country participation apart from the US and Russia, the COVAX Facility—the vaccines pillar of the World Health Organization’s Access to COVID-19 Tools (ACT) Accelerator—has secured at least 500 million doses, or 250 million courses, and financing for half of the targeted two billion doses by the end of 2021 in efforts to support globally coordinated access to covid-19 vaccines.ConclusionsThis study provides an overview of how high income countries have secured future supplies of covid-19 vaccines but that access for the rest of the world is uncertain. Governments and manufacturers might provide much needed assurances for equitable allocation of covid-19 vaccines through greater transparency and accountability over these arrangements.


2021 ◽  
Author(s):  
Taha Saleem

Road traffic crashes are one of the major causes of deaths and injuries around the world killing approximately 1.2 million people and injuring over 50 million every year. One of the primary goals of transportation agencies around the world is to reduce crashes as well as minimize the potential for human error and provide a forgiving road environment. Estimating the safety effects of highway design and operational elements is essential in achieving this goal. This research is divided into two components aimed at advancing the methodology for estimating these effects. The first component looks at evaluating the potential of cross-sectional analysis for developing crash modification factors/functions (CMFs/CMFunctions) used to represent the effects of safety treatments on crashes. First, the cross-sectional approach was used to investigate the safety effects of horizontal curvature on rural two-lane highways, which would be impossible to evaluate with before-after data. Second, this approach was further evaluated using databases of sites that were actually treated and similar, but untreated reference sites. The treatment databases for this part consisted of combination rumble strips (center line plus shoulder), wet reflective pavement markings and intersection conflict warning systems. The results from the cross-sectional analysis were then compared to recent studies where empirical Bayes before-after analysis was conducted with the same dataset used for the cross-sectional analysis. The results were promising in that the effects from the cross-sectional and before-after studies were reasonably comparable in each case. In addition, it was possible in some cases to relate the CMF to application circumstances by developing CMFunctions, providing results that could not be achieved in the before-after studies. The second component of this research involved development of roundabout crash predictions using conflicting volumes and delays, which could only be estimated from turning movement counts that are rarely collected at roundabouts. The object was to determine whether the considerable extra effort to collect these data would be worthwhile. The developed models were compared to the traditional models based on approach flows. The results suggest that collecting turning movement data, which is also required for capacity analysis, would be worthwhile for evaluating roundabout safety.


2012 ◽  
Vol 58 (4) ◽  
pp. 472-476 ◽  
Author(s):  
Caroline Filla Rosaneli ◽  
Flavia Auler ◽  
Carla Barreto Manfrinato ◽  
Claudine Filla Rosaneli ◽  
Caroline Sganzerla ◽  
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2017 ◽  
Vol 48 (S 01) ◽  
pp. S1-S45
Author(s):  
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S. Garbade ◽  
S. Kölker ◽  
G. Hoffmann ◽  
M. Ries

2019 ◽  
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Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 2174-PUB
Author(s):  
NARAYANAN NK ◽  
CS DWARAKANATH ◽  
VENKATARAMAN S ◽  
MANIKANDAN RM ◽  
NARENDRA BS ◽  
...  

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