Airbnb and COVID-19: SPACE-TIME vulnerability effects in six world-cities.

This study examines the COVID-19 vulnerability and subsequent market dynamics in the volatile hospitality market worldwide, by focusing in particular on individual Airbnb bookings-data for six world-cities in various continents over the period January 2020-August 2021. This research was done by: (i) looking into factual survival rates of Airbnb accommodations in the period concerned; (ii) examining place-based impacts of intra-city location on the economic performance of Airbnb facilities; (iii) estimating the price responses to the pandemic by means of a hedonic price model. In our statistical analyses based on large volumes of time- and space-varying data, multilevel logistic regression models are used to trace 'corona survivability footprints' and to estimate a hedonic price-elasticity-of-demand model. The results reveal hardships for the Airbnb market as a whole as well as a high volatility in prices in most cities. Our study highlights the vulnerability and 'corona echo-effects' on Airbnb markets for specific accommodation segments in several large cities in the world. It adds to the tourism literature by testing the geographic distributional impacts of the corona pandemic on customers' choices regarding type and intra-urban location of Airbnb accommodations.

Autotransplantation of Premolars With a 3-Dimensional Printed Titanium Replica of the Donor Tooth Functioning as a Surgical Guide: Proof of Concept.

PURPOSE: Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica of the donor tooth that functions as a surgical guide during autotransplantation. MATERIALS AND METHODS: Five consecutive procedures were prospectively observed. Transplantations of maxillary premolars with optimal root development were included in this study. A 3D-printed replica of the donor tooth was used to prepare a precisely fitting new alveolus at the recipient site before extracting the donor tooth. Procedure time, extra-alveolar time, and number of attempts needed to achieve a good fit of the donor tooth in the new alveolus were recorded. RESULTS: For each transplantation procedure, the surgical time was shorter than 30 minutes. An immediate good fit of the donor tooth in the new alveolus was achieved with an extra-alveolar time shorter than 1 minute for all transplantations. CONCLUSION: These results show that the extra-alveolar time is very short when the surgical guide is used; therefore, the chance of iatrogenic damage to the donor tooth is minimized. The use of a replica of the donor tooth makes the autotransplantation procedure easier for the surgeon and facilitates optimal placement of the transplant.

Interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups.

INTRODUCTION: The use of digital orthodontic setups has grown quickly. The purpose of this study was to test the interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups in OrthoCAD (Align Technology, San Jose, Calif). METHODS: Six clinicians made digital orthodontic setups on 6 digital models twice, with a minimum interval of 2 weeks and a maximum interval of 4 weeks. OrthoCAD software was used, and treatment goals were all set the same according to the American Board of Orthodontics Objective Grading System (ABO-OGS). Differences between the 72 setups were measured with the ABO-OGS scores. RESULTS: In comparing setups 1 and 2, the intraexaminer mean absolute differences in total ABO-OGS scores varied statistically significantly between 2.17 and 6.00 points. Interexaminer mean absolute differences varied statistically significantly between 4.77 and 5.56 points. All but 1 intraclass correlation coefficient (ICC) value showed significant excellent agreement (ICC, >0.8) for intraexaminer reliability. One ICC value was insignificant and showed moderate (ICC, 0.4-0.6) agreement. Interexaminer reliability showed significant good (ICC, 0.6-0.8) agreement. CONCLUSIONS: There is a significant difference in ABO-OGS score when using OrthoCAD. Although this difference was low, it could be clinically significant. Interexaminer and intraexaminer reliabilities are not redundant for general use of the 3-dimensional orthodontic digital setup in OrthoCAD.

A blueprint for strategic urban research: the urban piazza.

Urban research in many countries has failed to keep up with the pace of rapidly and constantly evolving urban change. The growth of cities, the increasing complexity of their functions and the complex intra- and inter-urban linkages in this 'urban century' demand new approaches to urban analysis, which, from a systemic perspective, supersede the existing fragmentation in urban studies. In this paper we propose the concept of the urban piazza as a framework in order to address some of the inefficiencies associated with current urban analysis. By combining wealth-creating potential with smart urban mobility, ecological resilience and social buzz in this integrated and systemic framework, the aim is to set the basis for a 'New Urban World' research blueprint, which lays the foundation for a broader and more integrated research programme for strategic urban issues.

Precision of identifying cephalometric landmarks with cone beam computed tomography in vivo.

The study aims were to assess the precision and time required to conduct cephalometric analysis with cone-beam computed tomography (CBCT) in vivo on both three-dimensional (3D) surface models and multi-planar reformations (MPR) images. Datasets from 10 patients scanned with CBCT were used to create two types of images: 1. axial, coronal, and sagittal MPR images and 2. 3D surface models. Eleven observers identified 22 cephalometric landmarks on 3D surface models first and then using 3D in combination with MPR images twice independently. Tracing time was recorded in both methods. Precision was defined as the absolute difference between an observer's repeated measurements and the mean of all measurements per landmark. Inter- and intra-observer agreements were defined as the absolute difference of the observers' measurements from each other and from their repeated measurements averaged over all landmarks, respectively. The precision of measurements ranged between 0.29 ± 0.17 and 2.82 ± 7.53. Adding MPR alongside, 3D surfaces improved the precision of tracing for 15 of 22 of the landmark but it took on average twice as much time. Mean time required to trace one patient was 6:03 ± 2:48 and 10:41 ± 4:01 minutes for 3D and 3D + MPR, respectively (P = 0.0001).

Fractal dimension complexity of gravitation fractals in central place theory.

Settlement centers of various types, including cities, produce basins of attraction whose shape can be regular or complexly irregular (from the point of view of geometry). This complexity depends in part on properties of the space surrounding a settlement. This paper demonstrates that by introducing a dynamic approach to space and by including an equation of motion and space resistance, a dramatic change in the stylized static CPT (Central Place Theory) image occurs. As a result of the interplay of gravitational forces, basins of attraction arise around cities, whose boundaries appear to be fractals. This study provides a wealth of spatial fractal complex images which may change the traditional understanding of CPT.

Spotlight on the region analytical contributions on regional development.

Regional science has, in its great history since the 1950s, made a decisive contribution to a better scientific understanding of spatial development issues and dynamics and to a more effective implementation of knowledge-based regional policy in many countries of the world, in both developed and developing nations on our planet. This special issue of the annals of regional science, titled "Spotlight on the Region", celebrates the scholarly importance and impact of the late Roger Stough on regional science. The issue is comprised of fourteen self-standing on regional and urban development and highlights the critical importance of regional and urban dimensions in sustainable development. They confirm once more the seminal significance of the contributions of one of the great giants in regional science, Roger Stough.

On the bumpy road to recovery: resilience of public transport ridership during COVID-19 in 15 European cities.

COVID-19 has a dramatic impact on the use of public transport (PT). Most European cities report a decline in PT use during 2020 and 2021. Nevertheless, not all cities report similar decline patterns or comparable resilience paths. We investigate the resilience patterns of PT use during 2020 and 2021 in 15 European cities from 11 different countries using clustering and regression analysis of data originating from Google Mobility Reports, the Oxford Policy Stringency Tracker, and COVID-19 reports. Results highlight the variety of resilience patterns of PT use in these 15 cities. These patterns vary in time and space. PT use in some cities recovered faster and more significantly than in others. Findings also suggest that changes in retail and recreational routines had the highest impact on the resilience of PT use in most cities. Changes in workplace routines are also important, but to a lesser degree. The impact of policy stringency on PT use is significant, but less consistent between the 15 cities.

Leisure mobility changes during the COVID-19 pandemic - An analysis of survey and mobile phone data in Sweden.

The COVID-19 pandemic affected travelling in general, and the leisure mobility and the spatial distribution of travellers in particular. In most parts of the world, both domestic and international travel has been replaced by restrictive policies and recommendations on mobility. A modal shift from public transport towards private cars and micro-mobility was also observed. This study seeks to trace the implications of the COVID-19 pandemic for leisure mobility. We use a unique Swedish database containing daily mobility patterns of pseudonymised mobile phone users, combined with a survey on vacation transport behaviour. By contrasting mobility patterns for selected holiday days during the unaffected summer of 2019 with corresponding dates in 2020 and 2021, we are able to model and detect the pandemic effects on tourism and recreational mobility. Moreover, by identifying the general mobility patterns, we analyse whether and how the transport mode has changed. Using data on the spatial distribution of recreational amenities, we identify locations that were favoured during the pandemic. In Sweden, even though the pandemic decreased in spread and severity during the summers, most travel restrictions were still enforced, international vacations uncommon, and larger vacation spots, such as amusement parks and cultural institutions, were closed down. Swedish vacation homes in remote or rural areas were quickly booked. This change in recreational behaviour, where less populated areas, open air and nature recreation were favoured over indoor or crowded urban cultural activities, was more substantial in 2021 than in 2020. This result shows how policies can effectively be developed, so that Swedes respond properly to recommendations and adjust their vacation plans.

A Meta-Overview and Bibliometric Analysis of Resilience in Spatial Planning - the Relevance of Place-Based Approaches.

This study offers a literature review and bibliometric analysis aiming to enhance our understanding of the actual contribution of resilience approaches to spatial and territorial development and planning studies. Using citation link-based clustering and statistical text-mining techniques (in terms of prevalence of topics, over time, extraction of relevant terms, keywords frequencies), our study maps scientific domains that include the spatial dimension of resilience thinking. It offers a systematic assessment of modern approaches by connecting profoundly theoretical views to more instrumental and policy-oriented approaches. Firstly, the theoretical background of spatial resilience used in numerous studies in various fields is analysed from the viewpoint of the type of embedded resilience (engineering, ecological, social-ecological, economic, social etc.). Secondly, we review and discuss the significance of three main and consistent research directions in terms of different scales and political/institutional contexts that matter from the viewpoint of spatial and territorial planning. Our findings show that spatial resilience debates are far from being settled, as according to many scientists, resilience measurements are often based on technical-reductionist frameworks that cannot comprehensively reflect the complex systems and issues they address. Our conclusions highlight the necessity of a harmonized framework and integrated perspective on resilience in sustainable territorial planning and development, in both theoretical and empirical contexts.

In Search of Concerted Strategies for Competitive and Resilient Regions.

The European space-economy represents a complex system with a great internal heterogeneity, intensive socioeconomic interactions and differential growth trajectories among countries and regions. The present study aims to investigate the connectivity between spatial competitiveness and resilience in Europe and seeks to design an operational framework for concerted strategies of competitive and resilient regions. To assess the linkage between resilience and competitiveness, we have developed a new measure, viz. the Resilience and Competitiveness Index (RACI) as a function of two constituent sub-indices: Resilience and Competitiveness. This approach is tested on the basis of detailed data on European regions. The empirical results from 268 EU NUTS2 regions offer a solid anchor point for the proposed operational framework for concerted development strategies of competitive and resilient regions. Our research distinguishes and proposes several systematic types of concerted regional strategies according to the performance of a region measured by Resilience and Competiveness sub-indices. A key result of the study is the design of an operational constellation for strategic regional policy evaluation, with a major added value for policy- and decision-making purposes. The use of official data from Eurostat and of standard indicators in our research assures continuity and consistency with the official Regional Competitiveness Index (RCI) classification and measurement, so that policy makers are able to compare the performance of their regions over time and to develop proper concerted strategies accordingly. The clear evidence of a connectivity between regional competitiveness and resilience may help to develop a governance approach that balances competitiveness (mainly represented by productive assets) with resilience (mainly represented by sustainability and ecological awareness) and thus to deal with the complexity in socioeconomic systems.

The role of pre-pandemic teleworking and E-commerce culture in the COVID-19 dispersion in Europe.

The threats of the coronavirus have shifted the workplace of many people from office to home and also made e-commerce the primary medium for purchases. While these changes were made in an effort to mitigate contagion, there are no studies, to the best of our knowledge, that address if teleworking and e-commerce culture prior to the pandemic influenced the dispersion of the virus. In our study we examine whether pre-existing teleworking practices and e-commerce activity have played an important role in the COVID-19 dispersion in Europe. Based on a set of data from all European countries, the present study employs the Philips & Sul methodology to explore corona convergence patterns. Our findings suggest that pre-existing e-commerce activity and teleworking practices had little to no effect in reducing the initial opportunities of individuals to contract the virus leading to the conclusion that other social interactions must have played a more important role.

The effect of health on economic growth: a meta-regression analysis.

The main objective of this study is to examine the effect of health on economic growth based on 719 estimates obtained from 64 studies from all over the world. We find evidence of a publication bias towards a positive estimated effect of health on economic growth. After accounting for heterogeneity of the estimates, we show that health has a genuine positive effect on economic growth. Less developed countries seem to enjoy a higher effect of health on growth driven by the ongoing economic-demographic transition in those countries. The variation of the health effect on economic growth is also influenced by the available data, estimation procedure, model specification, publication channel, and country characteristics in each study. Studies that do not account for endogeneity seem to create an upward bias. Studies with more comprehensive variables seem to increase the estimated effect of health on growth. A higher number of years of compulsory education, longer working experience, and more favourable environmental conditions also increase the effect size. Overall, our results confirm the key role of the health factor in explaining economic growth across countries.

The ideal neighbourhoods of successful ageing: A machine learning approach.

Ageing outcomes are shaped by not only health conditions, but also their interactions with the external environment. While the effects of some specific neighbourhood characteristics such as rurality on ageing have been evaluated in various studies, we still know little about the relative importance of particular natural and urban environments and how the impact varies at different stages of the ageing process. This article addresses these knowledge gaps by analysing survey data from 33 European countries using a machine learning method called multivariate regression trees (MRT). Multiple wellbeing indicators are combined to form an ageing profile for each individual in the survey. After studying these profiles using MRT, we find that generally the affordability of health facilities is a major determinant of life satisfaction, self-rated health condition and mental wellbeing for individuals in most age groups. Other important but age-specific determinants are neighbourhood safety and accessibility to cultural facilities and to green areas. In contrast, characteristics such as urbanity, transportation and air quality do not significantly influence ageing outcomes. Our findings lend support to the resources theory in explaining ageing outcomes and suggest that more resources may have to be directed to improve the affordability and quality of health care services, the policing services and the accessibility to cultural and green areas in order to achieve more favourable ageing outcomes.

Are global cities sustainability champions? A double delinking analysis of environmental performance of urban agglomerations.

Urban agglomerations - irrespective of their size or location - may act not only as engines of economic growth, but also as vehicles of environmental and climate sustainability that may stimulate both socio-economic achievements and environmentally-benign outcomes. Clearly, the efficiency of these outcomes may differ for different types of urban agglomeration in the world. This paper aims to present and test an advanced methodology for assessing economic and sustainability-oriented performance strategies for global cities, by developing and applying a super-efficient Data Envelopment Analysis (DEA) model. We compare 40 global cities - included in the Global Power City Index (GPCI) database - in a benchmark study in order to trace the highest-performing urban regions from both an economic and environmental-climatological efficiency perspective, by applying relevant quantitative GPCI indicators to these 40 cities. Our ultimate goal is to test what is termed the 'delinking' hypothesis, from the viewpoint of both economic prosperity and urban size externalities. This approach will be applied empirically by examining the GPCI data set comprised of various multi-dimensional and empirically verified indicators on economic performance and climatological-environmental conditions for the 40 global cities concerned. We regard both the size of these agglomerations and their economic welfare position as critical parameters for assessing their economic and environmental efficiency performance. In the framework of our original DEA approach, these urban areas are categorised according to 2x2 dimensions, viz. in terms of both agglomeration size (big or medium-sized) and the economic development level of the area (highly developed or developing/emerging). Our contribution serves to assess - by means of regression techniques - the highest performing agglomerations among the urban sustainability champions on the basis of the two above-mentioned assessment criteria. This approach provides the opportunity to test the so-called Kuznets sustainability curve under two different conditions, viz. agglomeration size and economic development. The study presents and interprets the empirical findings for these four classes of global cities.

The influence of cephalometrics on orthodontic treatment planning.

Since its introduction, cephalometrics, i.e. cephalometric radiography and analysis, has been used for orthodontic treatment planning. However, the effectiveness of this diagnostic method remains questionable. A randomized crossover study was designed to assess the influence of cephalometrics in orthodontic treatment planning of individual patients. Diagnostic records of 48 subjects (24 males and 24 females aged 11-14 years) were divided in two stratified groups and assigned to one of two combinations: A, dental casts only, and B, dental casts, cephalometric radiographs, and analysis. The records were presented to 10 orthodontic postgraduates and four orthodontists for formulation of orthodontic treatment plans containing a dichotomous decision regarding the use of a functional appliance (FUNC), rapid maxillary expansion (RME), and extraction (EXTR). The combination of FUNC + RME + EXTR was used as the basis of the outcome measure. Agreement on orthodontic treatment planning using all possible comparisons of diagnostic records of individual patients (AB, AA, and BB) was assessed and overall proportions of agreement (OPA) were calculated for orthodontic postgraduates and orthodontists separately. Median OPA were 0.60 (AB), 0.65 (AA), and 0.60 (BB) for orthodontic postgraduates and 0.50 (AB), 0.75 (AA), and 0.50 (BB) for orthodontists. Irrespective of the level of experience, neither consistency of orthodontic treatment planning between both combinations of diagnostic records showed a statistically significant difference (P > 0.05) using Wilcoxon signed rank test nor did consistencies and agreement of orthodontic treatment planning after the addition of cephalometrics. It appears that cephalometrics are not required for orthodontic treatment planning, as they did not influence treatment decisions.

Self-Organisation in Spatial Systems-From Fractal Chaos to Regular Patterns and Vice Versa.

This study offers a new perspective on the evolutionary patterns of cities or urban agglomerations. Such developments can range from chaotic to fully ordered. We demonstrate that in a dynamic space of interactive human behaviour cities produce a wealth of gravitational attractors whose size and shape depend on the resistance of space emerging inter alia from transport friction costs. This finding offers original insights into the complex evolution of spatial systems and appears to be consistent with the principles of central place theory known from the spatial sciences and geography. Our approach is dynamic in nature and forms a generalisation of hierarchical principles in geographic space.

The Measurement of Economic, Social and Environmental Performance of Countries: A Novel Approach.

This paper presents a new analytical framework for assessing spatial disparities among countries. It takes for granted that the analysis of a country's performance cannot be limited solely to either economic or social factors. The aim of the paper is to combine relevant economic and 'non-economic' (mainly social) aspects of a country's performance in an integrated logical framework. Based on this idea, a structural simultaneous equation model will be presented and estimated in order to explore the direction of the causal relationship between economic and non-economic aspects of a country's performance. Furthermore, an exploration of the trajectory that each country has registered over time along a virtuous path will be offered. By means of a matrix persistency/transition analysis, the countries will be classified in clusters of good/bad performance. One of the most interesting conclusions concerns the inability of most countries to turn the higher educational skills of the population into greater economic performance over time. In addition, our analysis also shows that making an accurate picture record and formulating related policy aiming at environmental care is highly desirable. It is surprising that only a few countries have reached a favourable economic and environmental performance simultaneously.

An operational information systems architecture for assessing sustainable transportation planning: principles and design.

This paper offers the description of an integrated information system framework for the assessment of transportation planning and management. After an introductory exposition, in the first part of the paper, a broad overview of international experiences regarding information systems on transportation is given, focusing in particular on the relationship between transportation system's performance monitoring and the decision-making process, and on the importance of this connection in the evaluation and planning process, in Italian and European cases. Next, the methodological design of an information system to support efficient and sustainable transportation planning and management aiming to integrate inputs from several different data sources is presented. The resulting framework deploys modular and integrated databases which include data stemming from different national or regional data banks and which integrate information belonging to different transportation fields. For this reason, it allows public administrations to account for many strategic elements that influence their decisions regarding transportation, both from a systemic and infrastructural point of view.