A curvature-free Log(2k-1) Theorem

This paper presents a curvature-free version of the Log(2k-1) Theorem of Anderson, Canary, Culler & Shalen [ACCS96]. It generalizes a result by Hou [Hou01] and its proof is rather straightforward once we know the work by Lim [Lim08] on volume entropy for graphs. As a byproduct we obtain a curvature-free version of the Collar Lemma in all dimensions.Comment: Accepted for publication in Proceedings of the AMS. Title Changed (formerly entitled "Volume entropy and lengths of homotopically independent loops"

On the Voting Power of an Alliance and the Subsequent Power of its Members

Even, and in fact chiefly, if two or more players in a voting gamehave on a binary issue independent opinions, they may haveinterest to form a single voting alliance giving an average gainof influence for all of them. Here, assuming the usualindependence of votes, we first study the alliance voting powerand obtain new results in the so-called asymptotic limit for whichthe number of players is large enough and the alliance weightremains a small fraction of the total of the weights. Then, wepropose to replace the voting game inside the alliance by a randomgame which allows new possibilities. The validity of theasymptotic limit and the possibility of new alliances are examinedby considering the decision process in the Council of Ministers ofthe European Union.Voting Power; Alliance

Bending laminations on convex hulls of anti-de Sitter quasicircles

Let $\lambda_-$ and $\lambda_+$ be two bounded measured laminations on the hyperbolic disk $\mathbb H^2$, which "strongly fill" (definition below). We consider the left earthquakes along $\lambda_-$ and $\lambda_+$, considered as maps from the universal Teichm\"uller space $\mathcal T$ to itself, and we prove that the composition of those left earthquakes has a fixed point. The proof uses anti-de Sitter geometry. Given a quasi-symmetric homeomorphism $u:{\mathbb RP}^1\to {\mathbb RP}^1$, the boundary of the convex hull in $AdS^3$ of its graph in ${\mathbb RP}^1\times{\mathbb RP}^1\simeq \partial AdS^3$ is the disjoint union of two embedded copies of the hyperbolic plane, pleated along measured geodesic laminations. Our main result is that any pair of bounded measured laminations that "strongly fill" can be obtained in this manner.Comment: 16 page

Entropie minimale des espaces localement symétriques

In this thesis we give an overview of the volume entropy rigidity problem. A conjecture by Gromov and Katok states that, on a locally symmetric space (M; g0), the symmetric metric g0 has minimal volume entropy among metrices with the same total volume. The text is self-contained, assuming a basic knowledge in differential geometry. Therefore we discuss in the first chapter some background material used in the sequel. The case of compact quotients of H2 _ H2 was unknown before this work ; we give a fully detailled proof. The key-point is to build a calibrating form as in [BCG95]. As a by-product, we present some applications provided by the proof of the volume entropy rigidity conjecture. We conclude by an informal section explaining the motivations of the problem to a non-mathematical reader.Nous donnons dans cette thèse une preuve du problème de l’entropie volumique minimale dans les quotients compacts de H2_H2. Une conjecture de Gromov et Katok prétend en effet que, sur un espace localement symétrique (M; g0), la métrique de plus petite entropie volumique parmi les métriques de volume fixé est la métrique g0. Le texte se veut relativement abordable. C’est pourquoi nous avons intégré un premier chapitre qui contient une bonne partie du matériel qui sera utilisé par la suite. Puis nous passons en revue les preuves des différents cas du problème déjà traités. Le cas des quotients compacts de H2_H2 n’était pas connu avant ce travail ; nous en détaillons minutieusement la preuve. Notre démarche consiste à faire fonctionner la méthode de calibration imaginée dans [BCG95]. Nous présentons aussi les principales applications qui découlent de la preuve de la conjecture de Gromov et Katok. Nous concluons par une discussion heuristique qui explique les enjeux du problème que nous étudions

Accessibility, Travel Behavior, and Urban Form Change

Accessibility is a central concept for urban planning both from theoretical and practical perspectives. Theoretically, accessibility is a major driver of patterns of land value and residential density in metropolitan urban regions. Practically, planning for accessibility offers the opportunity to shift away from transportation planning's historic focus on mobility (speed) and towards a focus on greater land use-transportation integration. This dissertation takes as its premise that transportation planners ought to be planning for higher accessibility and traces some of its implications. Does higher regional accessibility lead to the travel patterns that planners and travel behavior researchers expect? How are US metropolitan regions performing with regard to an accessibility-based performance benchmark over time? There is broad consensus among transportation researchers that accessibility measures indicate the ease of access to opportunities across space. Theoretically, we expect households in such high accessibility areas to travel less in distance on a per trip basis, but with greater trip frequency and with a greater range of choices than similar households in lower accessibility areas. This dissertation explores the connection between high accessibility locations and such types of travel patterns. In specific, two of the three dissertation papers explore the accessibility-travel behavior relationship: Measuring Complete Communities and Does Accessibility Influence Activity Participation? These two papers ask what types of built environments are associated with more localized travel and more frequent travel. Interestingly, both of these papers find that local accessibility may be more important for supporting these desired travel patterns than regional accessibility. Furthermore, if planners should be planning for higher regional accessibility for households, how are metropolitan planning agencies performing based upon this metric? This is the question asked by the third dissertation paper, Changing Accessibility in US Metropolitan Areas. This paper examines the accessibility performance of four contrasting metropolitan areas over time. Changing travel times are found to have a greater influence over accessibility change than changing urban forms. Tracking accessibility change over time provides planners with an alternative view of urban sprawl; metros with lowering accessibility are presumably providing decreased access to opportunity for their residents over time.Doctor of Philosoph

Big Data, Accessibility, and Urban House Prices

Acknowledgements: The authors thank Andrew VanValin, Estefania Mayorga, and Jessica Kluttz for helpful research assistance. We also thank the reviewers and editors for helping us to improve the paper. Funding: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Land Economics Foundation.Peer reviewedPostprin

Structure du Budget D’investissements Publics de Sante Dans la Region du Centre/Cameroun (2013-2017)

Entre 2013 et 2017, le budget d’investissements publics du Ministère de la santé publique alloué à la région du Centre est passé de 2 093 800 000 francs CFA à 17 903 270 000. Le montant cumulé de ces investissements publics en santé dans la région était de 37 185 970 000 francs CFA. En dépit de ces investissements massifs, les populations de la région en général et celles des zones rurales en particulier éprouvent des difficultés pour accéder aux soins et services de santé. L’objectif de cet article est de cartographier le type de projets inscrits au budget d’investissements publics en santé alloués à la région du Centre afin d’évaluer s’ils sont de nature à améliorer l’offre de soins et services de santé pour les populations. L’analyse des allocations de projets révèle qu’en termes d’effectif, le nombre et le type de projets alloués à la région du Centre pourraient concourir à améliorer l’offre de soins en son sein. Toutefois, les volumes financiers dédiés à ces investissements restent insuffisants, ce qui explique en partie le fait que les populations de cette région éprouvent des difficultés à accéder aux soins et services de santé. Between 2013 and 2017, the public investment budget of the Ministry of Public Health allocated to the Central region increased from 2,093,800,000 CFA francs to 17,903,270,000 CFA francs. The cumulative amount of these public investments in health in the region was 37,185,970,000 CFA francs. Despite these massive investments, the region's populations in general and those in rural areas in particular are facing difficulties in accessing health care and services. The objective of this article is to map the type of projects included in the public health investment budget allocated to the Central region in order to assess whether they are likely to improve the provision of health care and services for the populations. The analysis of project allocations reveals that in terms of staffing levels, the number and type of projects allocated to the Centre could help improve the supply of care within the Centre. However, the financial volumes dedicated to these investments remain insufficient, which partly explains the fact that the region's populations are experiencing difficulties in accessing health care and services

Review of the current status of RAS mutation testing in patients with metastatic colorectal cancer (mCRC): Flash-RAS study

Présentation PosterInternational audienceOBJECTIVES: In 2013, it was shown that mutations in KRAS exons 3 and 4, or NRAS exons 2 to 4 had a similar effect. The primary objective was to assess the practices in conducting RAS testing in 2014. The secondary objectives were to describe the evolution of the RAS testing prescription rates from 2011, the process and time required to obtain the results, and to analyze their impact on the therapeutic strategy. METHODS: FLASH-RAS is an observational retrospective French multicenter study. RESULTS: 375 mCRC patients diagnosed and initiating a 1st line treatment (L1) between March and June 2014 were analyzed. For 90.1% of the patients (IC95%= [87.1%; 93.2%]), a genotyping request for RAS biomarkers was made in L1, i.e. a significantly increased rate compared to 2011 (81.1% in 2011, p<0.001). For 75% of the patients, the request was made before or at least one month after the diagnosis of the first metastases (1st M). No increase was observed in the median and mean times to obtain the test results between 2011 and 2014 despite the increased number of exons tested. CONCLUSIONS: In 2014, the rate of RAS genotyping requests has been increasing since 2011. For a majority of patients, the request is made before or at the latest one month after 1st M diagnosis. Nevertheless, for 24.5% of the patients, the request is made more than one month after 1st M diagnosis, which is not compatible with an informed treatment decision in L1

Longitudinal Analysis of Adolescent Girls' Activity Patterns: Understanding the Influence of the Transition to Licensure

The proportion of teens and young adults with driver's licenses has declined sharply in many industrialized countries including the United States. Explanations for this decline have ranged from the introduction of graduated driver licensing programs to the increase in online social interaction. We used a longitudinal cohort study of teenage girls in San Diego and Minneapolis to evaluate factors associated with licensure and whether teens' travel patterns become more independent as they aged. We found that licensure depended not only on age, but on race and ethnicity as well as variables that correlate with household income. Results also showed evidence that teen travel became more independent as teen's age, and that acquiring a license is an important part of this increased independence. However, we found limited evidence that teen's travel-activity patterns changed as a result of acquiring a driver's license. Rather, teen independence resulted in less parental chauffeuring, but little shift in travel patterns. For the larger debate on declining Millennial mobility, our results suggest the need for more nuanced attention to variation across demographic groups and consideration of the equity implications if declines in travel and licensure are concentrated in low-income and minority populations