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1.
Sci Rep ; 12(1): 16522, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192435

RESUMO

Human travel fed the worldwide spread of COVID-19, but it remains unclear whether the volume of incoming air passengers and the centrality of airports in the global airline network made some regions more vulnerable to earlier and higher mortality. We assess whether the precocity and severity of COVID-19 deaths were contingent on these measures of air travel intensity, adjusting for differences in local non-pharmaceutical interventions and pre-pandemic structural characteristics of 502 sub-national areas on five continents in April-October 2020. Ordinary least squares (OLS) models of precocity (i.e., the timing of the 1st and 10th death outbreaks) reveal that neither airport centrality nor the volume of incoming passengers are impactful once we consider pre-pandemic demographic characteristics of the areas. We assess severity (i.e., the weekly death incidence of COVID-19) through the estimation of a generalized linear mixed model, employing a negative binomial link function. Results suggest that COVID-19 death incidence was insensitive to airport centrality, with no substantial changes over time. Higher air passenger volume tends to coincide with more COVID-19 deaths, but this relation weakened as the pandemic proceeded. Different models prove that either the lack of airports in a region or total travel bans did reduce mortality significantly. We conclude that COVID-19 importation through air travel followed a 'travel as spark' principle, whereby the absence of air travel reduced epidemic risk drastically. However, once some travel occurred, its impact on the severity of the pandemic was only in part associated with the number of incoming passengers, and not at all with the position of airports in the global network of airline connections.


Assuntos
Viagem Aérea , COVID-19 , Aeroportos , COVID-19/epidemiologia , Surtos de Doenças , Humanos , Pandemias , Viagem
2.
Case Stud Transp Policy ; 10(1): 257-268, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34956834

RESUMO

The analysis of mobile phones data at regional level in the EU reveals varying patterns in mobility trends during the Covid-19 pandemic. These depend on the temporal evolution of the pandemic in each EU Member State, the measures taken at local or national level to limit the growth of the pandemic, as well as the level of urbanization and type of economic activity in each region. During the first phase of the pandemic (March- April 2020) the decrease in mobility was in general uniform among regions in the same Member State, especially in Italy, Spain and France, where national level measures were adopted. A relaxation of the measures and a resulting rebound of mobility was evident during the summer period (July- August 2020). At the same time, a shift from urban to rural areas during the summer vacation period is evident, with especially touristic areas increasing the number of movements in the same Member State. The variance in mobility trends during the second wave of the pandemic (October- November 2020) was higher, a result of the predominantly local and regional level measures applied in each Member State. Those insights suggest a certain correlation between the level of mobility and the evolution of the pandemic at regional level. The association with high levels of Covid-19 prevalence is particularly strong in urban regions with high mobility levels.

3.
Transportation (Amst) ; 49(6): 1999-2025, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34608340

RESUMO

This work introduces a new concept of functional areas called Mobility Functional Areas (MFAs), i.e., the geographic zones highly interconnected according to the analysis of mobile positioning data. The MFAs do not coincide necessarily with administrative borders as they are built observing natural human mobility and, therefore, they can be used to inform, in a bottom-up approach, local transportation, spatial planning, health and economic policies. After presenting the methodology behind the MFAs, this study focuses on the link between the COVID-19 pandemic and the MFAs in Austria. It emerges that the MFAs registered an average number of infections statistically larger than the areas in the rest of the country, suggesting the usefulness of the MFAs in the context of targeted re-escalation policy responses to this health crisis. The MFAs dataset is openly available to other scholars for further analyses.

4.
Jpn J Stat Data Sci ; 4(1): 763-781, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35425884

RESUMO

Due to an unprecedented agreement with the European Mobile Network Operators, the Joint Research Centre of the European Commission was in charge of collecting and analyze mobile positioning data to provide scientific evidence to policy makers to face the COVID-19 pandemic. This work introduces a live anomaly detection system for these high-frequency and high-dimensional data collected at European scale. To take into account the different granularity in time and space of the data, the system has been designed to be simple, yet robust to the data diversity, with the aim of detecting abrupt increase of mobility towards specific regions as well as sudden drops of movements. A web application designed for policy makers, makes possible to visualize the anomalies and perceive the effect of containment and lifting measures in terms of their impact on human mobility as well as spot potential new outbreaks related to large gatherings.

5.
PLoS One ; 15(9): e0238947, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915875

RESUMO

The paper explores the travelling behaviour of migrant groups using Facebook audience estimates. Reduced geographical mobility is associated with increased risk of social exclusion and reduced socio-economic and psychological well-being. Facebook audience estimates are timely, openly available and cover most of the countries in the world. Facebook classifies its users based on multiple attributes such as the country of their previous residence, and whether they are frequent travellers. Using these data, we modelled the travelling behaviour of Facebook users grouped by countries of previous and current residence, gender and age. We found strong indications that the frequency of travelling is lower for Facebook users migrating from low-income countries and for women migrating from or living in countries with high gender inequality. Such mobility inequalities impede the smooth integration of migrants from low-income countries to new destinations and their well-being. Moreover, the reduced mobility of women who have lived or currently live in countries with conservative gender norms capture another aspect of the integration which is referring to socio-cultural norms and gender inequality. However, to provide more solid evidence on whether our findings are also valid for the general population, collaboration with Facebook is required to better understand how the data is being produced and pre-processed.


Assuntos
Mídias Sociais , Migrantes/psicologia , Viagem/psicologia , Comportamento , Feminino , Humanos , Renda , Análise dos Mínimos Quadrados , Masculino , Modelos Psicológicos , Pobreza/psicologia , Análise de Regressão , Sexismo/psicologia , Fatores Socioeconômicos , Migrantes/classificação , Viagem/economia
6.
Saf Sci ; 132: 104925, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32952303

RESUMO

This work presents a mobility indicator derived from fully anonymised and aggregated mobile positioning data. Even though the indicator does not provide information about the behaviour of individuals, it captures valuable insights into the mobility patterns of the population in the EU and it is expected to inform responses against the COVID-19 pandemic. Spatio-temporal harmonisation is carried out so that the indicator can provide mobility estimates comparable across European countries. The indicators are provided at a high spatial granularity (up to NUTS3). As an application, the indicator is used to study the impact of COVID-19 confinement measure on mobility in Europe. It is found that a large proportion of the change in mobility patterns can be explained by these measures. The paper also presents a comparative analysis between mobility and the infection reproduction number R t over time. These findings will support policymakers in formulating the best data-driven approaches for coming out of confinement, mapping the socio-economic effects of the lockdown measures and building future scenarios in case of new outbreaks.

7.
Nonlinear Dyn ; 101(3): 1901-1919, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32905053

RESUMO

Countries in Europe took different mobility containment measures to curb the spread of COVID-19. The European Commission asked mobile network operators to share on a voluntarily basis anonymised and aggregate mobile data to improve the quality of modelling and forecasting for the pandemic at EU level. In fact, mobility data at EU scale can help understand the dynamics of the pandemic and possibly limit the impact of future waves. Still, since a reliable and consistent method to measure the evolution of contagion at international level is missing, a systematic analysis of the relationship between human mobility and virus spread has never been conducted. A notable exceptions are France and Italy, for which data on excess deaths, an indirect indicator which is generally considered to be less affected by national and regional assumptions, are available at department and municipality level, respectively. Using this information together with anonymised and aggregated mobile data, this study shows that mobility alone can explain up to 92% of the initial spread in these two EU countries, while it has a slow decay effect after lockdown measures, meaning that mobility restrictions seem to have effectively contribute to save lives. It also emerges that internal mobility is more important than mobility across provinces and that the typical lagged positive effect of reduced human mobility on reducing excess deaths is around 14-20 days. An analogous analysis relative to Spain, for which an IgG SARS-Cov-2 antibody screening study at province level is used instead of excess deaths statistics, confirms the findings. The same approach adopted in this study can be easily extended to other European countries, as soon as reliable data on the spreading of the virus at a suitable level of granularity will be available. Looking at past data, relative to the initial phase of the outbreak in EU Member States, this study shows in which extent the spreading of the virus and human mobility are connected. The findings will support policymakers in formulating the best data-driven approaches for coming out of confinement and mostly in building future scenarios in case of new outbreaks.

8.
PLoS One ; 15(5): e0230494, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437445

RESUMO

The mobile nature of fishing activity entails dynamic spatial relations and dependencies between coastal communities and fishing grounds drawn by the movement of fishing vessels. Analysing these spatial relations is essential to allocate the socio-economic impact of the fishing activity into the relevant coastal communities. In addition, such spatial information gives the possibility, on the one hand, to assess the impacts from fisheries on the marine environment and, on the other, to manage competing uses of the sea space between different activities. In this paper, we use AIS data, which is individual vessels' positioning data, to examine the activity of the EU large-scale fishing fleets, their home ports, high intensity fishing areas (i.e., main fishing grounds), main ports and coastal communities involved.


Assuntos
Conservação dos Recursos Naturais/economia , Pesqueiros/economia , Mapeamento Geográfico , Navios/economia , Instalações de Transporte , Europa (Continente)
9.
Saf Sci ; 129: 104791, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32377034

RESUMO

Due to the coronavirus global crisis, most countries have put in place restrictive measures in order to confine the pandemia and contain the number of casualties. Among the restrictive measures, air traffic suspension is certainly quite effective in reducing the mobility on the global scale in the short term but it also has high socio-economic impact on the long and short term. The main focus of this study is to collect and prepare data on air passengers traffic worldwide with the scope of analyze the impact of travel ban on the aviation sector. Based on historical data from January 2010 till October 2019, a forecasting model is implemented in order to set a reference baseline. Making use of airplane movements extracted from online flight tracking platforms and on-line booking systems, this study presents also a first assessment of recent changes in flight activity around the world as a result of the COVID-19 pandemic. To study the effects of air travel ban on aviation and in turn its socio-economic, several scenarios are constructed based on past pandemic crisis and the observed flight volumes. It turns out that, according to these hypothetical scenarios, in the first Quarter of 2020 the impact of aviation losses could have negatively reduced World GDP by 0.02% to 0.12% according to the observed data and, in the worst case scenarios, at the end of 2020 the loss could be as high as 1.41-1.67% and job losses may reach the value of 25-30 millions. Focusing on EU27, the GDP loss may amount to 1.66-1.98% by the end of 2020 and the number of job losses from 4.2 to 5 millions in the worst case scenarios. Some countries will be more affected than others in the short run and most European airlines companies will suffer from the travel ban. We hope that these preliminary results may be of help for informed policy making design of exit strategies from this global crisis.

10.
PLoS One ; 14(10): e0224134, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31648280

RESUMO

Quantifying global international mobility patterns can improve migration governance. Despite decades of calls by the international community to improve international migration statistics, the availability of timely and disaggregated data about long-term and short-term migration at the global level is still very limited. In this study, we investigate the feasibility of using non-traditional data sources to fill existing gaps in migration statistics. To this end, we use anonymised and publicly available data provided by Facebook's advertising platform. Facebook's advertising platform classifies its users as "lived in country X" if they previously lived in country X, and now live in a different country. Drawing on statistics about Facebook Network users (Facebook, Instagram, Messenger, and the Audience Network) who have lived abroad and applying a sample bias correction method, we estimate the number of Facebook Network (FN) "migrants" in 119 countries of residence and in two time periods by age, gender, and country of previous residence. The correction method estimates the probability of a person being a FN user based on age, sex, and country of current and previous residence. We further estimate the correlation between FN-derived migration estimates and reference official migration statistics. By comparing FN-derived migration estimates in two different time periods, January-February and August-September 2018, we successfully capture the increase in Venezuelan migrants in Colombia and Spain in 2018. FN-derived migration estimates cannot replace official migration statistics, as they are not representative, and the exact methods the FN uses for classifying its users are not known, and might change over time. However, after carefully assessing the validity of the FN-derived estimates by comparing them with data from reliable sources, we conclude that these estimates can be used for trend analysis and early-warning purposes.


Assuntos
Emigração e Imigração , Dinâmica Populacional , Mídias Sociais/estatística & dados numéricos , Adolescente , Adulto , Publicidade , Países em Desenvolvimento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
PLoS One ; 10(6): e0130746, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26098430

RESUMO

Several research initiatives have been undertaken to map fishing effort at high spatial resolution using the Vessel Monitoring System (VMS). An alternative to the VMS is represented by the Automatic Identification System (AIS), which in the EU became compulsory in May 2014 for all fishing vessels of length above 15 meters. The aim of this paper is to assess the uptake of the AIS in the EU fishing fleet and the feasibility of producing a map of fishing effort with high spatial and temporal resolution at European scale. After analysing a large AIS dataset for the period January-August 2014 and covering most of the EU waters, we show that AIS was adopted by around 75% of EU fishing vessels above 15 meters of length. Using the Swedish fleet as a case study, we developed a method to identify fishing activity based on the analysis of individual vessels' speed profiles and produce a high resolution map of fishing effort based on AIS data. The method was validated using detailed logbook data and proved to be sufficiently accurate and computationally efficient to identify fishing grounds and effort in the case of trawlers, which represent the largest portion of the EU fishing fleet above 15 meters of length. Issues still to be addressed before extending the exercise to the entire EU fleet are the assessment of coverage levels of the AIS data for all EU waters and the identification of fishing activity in the case of vessels other than trawlers.


Assuntos
Coleta de Dados/métodos , Pesqueiros/estatística & dados numéricos , Mapeamento Geográfico , Navios , União Europeia , Pesqueiros/legislação & jurisprudência , Pesqueiros/métodos , Comunicações Via Satélite
12.
Mar Pollut Bull ; 73(1): 199-209, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23790462

RESUMO

Today the health of ocean is in danger as it was never before mainly due to man-made pollutions. Operational activities show regular occurrence of accidental and deliberate oil spill in European waters. Since the areas covered by oil spills are usually large, satellite remote sensing particularly Synthetic Aperture Radar represents an effective option for operational oil spill detection. This paper describes the development of a fully automated approach for oil spill detection from SAR. Total of 41 feature parameters extracted from each segmented dark spot for oil spill and 'look-alike' classification and ranked according to their importance. The classification algorithm is based on a two-stage processing that combines classification tree analysis and fuzzy logic. An initial evaluation of this methodology on a large dataset has been carried out and degree of agreement between results from proposed algorithm and human analyst was estimated between 85% and 93% respectively for ENVISAT and RADARSAT.


Assuntos
Monitoramento Ambiental/métodos , Poluição por Petróleo , Petróleo/análise , Radar , Poluentes Químicos da Água/análise , Algoritmos , Benchmarking , Humanos , Tecnologia de Sensoriamento Remoto , Poluição Química da Água/estatística & dados numéricos
13.
Mar Pollut Bull ; 60(1): 91-102, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19775709

RESUMO

Satellite services that deliver information about possible oil spills at sea currently use different labels of "confidence" to describe the detections based on radar image processing. A common approach is to use a classification differentiating between low, medium and high levels of confidence. There is an ongoing discussion on the suitability of the existing classification systems of possible oil spills detected by radar satellite images with regard to the relevant significance and correspondence to user requirements. This paper contains a basic analysis of user requirements, current technical possibilities of satellite services as well as proposals for a redesign of the classification system as an evolution towards a more structured alert system. This research work offers a first review of implemented methodologies for the categorisation of detected oil spills, together with the proposal of explorative ideas evaluated by the European Group of Experts on satellite Monitoring of sea-based oil Pollution (EGEMP).


Assuntos
Vazamento de Resíduos Químicos , Desastres , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Petróleo/análise , Comunicações Via Satélite , Poluentes Químicos da Água/análise , Europa (Continente) , Interpretação de Imagem Assistida por Computador , Cooperação Internacional , Oceanos e Mares , Petróleo/toxicidade , Radar/instrumentação , Medição de Risco , Gestão da Segurança , Astronave , Poluentes Químicos da Água/toxicidade
14.
Integr Comp Biol ; 48(1): 74-84, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21669774

RESUMO

Bats are among the few predators that can exploit the large quantities of aerial insects active at night. They do this by using echolocation to detect, localize, and classify targets in the dark. Echolocation calls are shaped by natural selection to match ecological challenges. For example, bats flying in open habitats typically emit calls of long duration, with long pulse intervals, shallow frequency modulation, and containing low frequencies-all these are adaptations for long-range detection. As obstacles or prey are approached, call structure changes in predictable ways for several reasons: calls become shorter, thereby reducing overlap between pulse and echo, and calls change in shape in ways that minimize localization errors. At the same time, such changes are believed to support recognition of objects. Echolocation and flight are closely synchronized: we have monitored both features simultaneously by using stereo photogrammetry and videogrammetry, and by acoustic tracking of flight paths. These methods have allowed us to quantify the intensity of signals used by free-living bats, and illustrate systematic changes in signal design in relation to obstacle proximity. We show how signals emitted by aerial feeding bats can be among the most intense airborne sounds in nature. Wideband ambiguity functions developed in the processing of signals produce two-dimensional functions showing trade-offs between resolution of time and velocity, and illustrate costs and benefits associated with Doppler sensitivity and range resolution in echolocation. Remarkably, bats that emit broadband calls can adjust signal design so that Doppler-related overestimation of range compensates for underestimation of range caused by the bat's movement in flight. We show the potential of our methods for understanding interactions between echolocating bats and those prey that have evolved ears that detect bat calls.

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