Earth's Interior from VLBI and Superconducting Gravimeter Data

International audienceWe analyze VLBI delays back to 1984 from the permanent geodetic network, and ten superconducting gravimeter records from the Global Geodynamic Project spanning more than 7 years. From the former data, we deduce nutation o sets, and from the latter we get gravimetric factors. Comparison of these observed quantities against theoretical expressions of the core and mantle admittance to the tidal potential allows us to estimate Love numbers and resonant frequencies and quality factors of the core. We point out strengths and deficiencies of each technique in their ability to retrieve the Earth's interior parameters

‘From Sanctuary to Welcoming Cities’: Negotiating the Social Inclusion of Undocumented Migrants in Liège, Belgium

Cities have become important sites of sanctuary for migrants with a precarious legal status. While many national governments in Europe have adopted restrictive immigration policies, urban governments have undertaken measures to safeguard undocumented residents’ rights. Existing scholarship on sanctuary cities has mostly focused on how cities’ stance against federal immigration policies can be interpreted as urban citizenship. What is largely missing in these debates, however, is a better insight into the role that local civil society actors play in pushing for sanctuary and negotiating the terms of social in- and exclusion. In this article, we rely on a qualitative study of the 2017 Sanctuary City campaign in Liège, Belgium, to argue that power relations between (and among) civil society actors and city officials help to explain why the meaning and inclusiveness of ‘sanctuary’ shifted over time. Initially, radical activists were able to politicize the issue by demanding the social inclusion of the ‘sans-papiers’ through grassroots mobilization. However, the cooptation of the campaign by immigrant rights organizations led to the adoption of a motion wherein the local government depicted the city as a ‘welcoming’ instead of a ‘sanctuary’ city. By showing how immigrant rights professionals sidelined radical activists during the campaign, we highlight the risk of depoliticization when civil society actors decide to cooperate with local governments to extend immigrant rights. We also underline the potential representational gap that emerges when those who are directly implicated, namely undocumented migrants, are not actively involved in campaigns that aim to improve their inclusion

Observation of the Earth’s nutation by the VLBI: how accurate is the geophysical signal

International audienceWe compare nutation time series determined by several International VLBI Service for geodesy and astrometry (IVS) analysis centers. These series were made available through the International Earth Rotation and Reference Systems Service (IERS). We adjust the amplitudes of the main nutations, including the free motion associated with the free core nutation (FCN). Then, we discuss the results in terms of physics of the Earth’s interior. We find consistent FCN signals in all of the time series, and we provide corrections to IAU 2000A series for a number of nutation terms with realistic errors. It appears that the analysis configuration or the software packages used by each analysis center introduce an error comparable to the amplitude of the prominent corrections. We show that the inconsistencies between series have significant consequences on our understanding of the Earth’s deep interior, especially for the free inner core resonance: they induce an uncertainty on the FCN period of about 0.5 day, and on the free inner core nutation (FICN) period of more than 1000 days, comparable to the estimated period itself. Though the FCN parameters are not so much affected, a 100% error shows up for the FICN parameters and prevents from geophysical conclusions

2500 years from dendrochronology back to ancient French human biotopes. Trees studied: low altitude oaks

We propose an experimental method, using curvilinear regressions, called corridor method, for dating and building a global useful signal based on oak ring widths in northern and eastern France. The resulting signal seems to be more useful than others to progress in the domains of ancient climate and ancient environments: dendrodating, dendroclimatology, dendroecology and, of course, human history (Lambert, 2002, Houbrechts and Lambert, 2004, Durost, 2005). However, we were lead to adapt or reconsider several basic mathematical functions, meteorological indexes or common dendrochronological definitions. We are currently working towards the publication of a large Data Base (web-DB). A first element of this DB can be consulted on the website of the ChronoEcology laboratory (French keywords: chrono-Ecologie, dendrochronologie). A discussion has opened about the participation of private contributors to such a public DB. The private contributors to this note agreed to show a part of their data without rights (money) and to justify explicitly their owndating procedures

Иерархическая организация мира, интеллект и сознание

Отказ от фиксированной сложности элементов нижележащих уровней позволил показать, что с точки зрения иерархической организации неживые тела, живые организмы и сознание существуют одинаковым образом, как физическая реальность. Такие свойства сознания, как целостность, контекстность, переживание и чувствование, можно описать только с позиции физического существования, но не формальных или алгоритмических систем. Делается вывод, что сознание не может быть получено с помощью машины Тьюринга и иных вычислительных систем, основанных на формальных принципах.Відмова від фіксованої складності елементів долішніх рівней дозволили показати, що з точки зору ієрархічної організації неживі тіла, живі організми та свідомість існують однаковим чином, як фізична реальність. Такі властивості свідомості, як цілісність, контекстність, переживання та почування, можливо описати лише за позиції фізичного існування, але не формальних або алгоритмічних систем. Робиться висновок, що свідомість не може бути отримана з допомогою машини Тьюрінгу і інших обчислювальних систем, заснованих на формальних принципах.Refusal from fixed complexity of elements of underlying levels has allowed to show that from the point of view of the hierarchical organization lifeless bodies, live organisms and consciousness exist equally, as a physical reality. Such properties of consciousness as integrity, contextual, and feeling it is possible to reproduce experience only from a position of physical existence, but not formal or algorithmic systems. The conclusion becomes that the consciousness cannot be received by means of the machine of the Turing and other computing systems based on formal principles

A Search for the Free Inner Core Nutation in VLBI Data

International audienceWe investigate the time-frequency spectrum of VLBI nutation series, including operational series released by IVS analysis centers. We focus on the interannual prograde band, where the signal as- sociated with the free inner core nutation (FICN) should be searched. We do not conclude on the detection of the FICN. However, we point out some signi cant but unexplained structures within the FICN frequency band. We also investigate whether their origin is geophysical or they are artifacts due to VLBI analysis methods or reference frame effects

Kinematic Characterisation of Hexapods for Industry

International audiencePurpose-The aim of this paper is to propose two simple tools for the kinematic characterization of hexapods. The paper also aims to share the authors' experience with converting a popular commercial motion base (Stewart-Gough platform, hex-apod) to an industrial robot for use in heavy duty aerospace manufacturing processes. Design/methodology/approach-The complete workspace of a hexapod is a six-dimensional entity that is impossible to visualize. Thus, nearly all hexapod manufacturers simply state the extrema of each of the six dimensions, which is very misleading. As a compromise, we propose a special three-dimensional subset of the complete workspace, an approximation of which can be readily obtained using a CAD/CAM software suite, such as CATIA. While calibration techniques for serial robots are readily available, there is still no generally-agreed procedure for calibrating hexapods. We propose a simple calibration method that relies on the use of a laser tracker and requires no programming at all. Instead, the design parameters of the hexapod are directly and individually measured and the few computations involved are performed in a CAD/CAM software such as CATIA. Findings-The conventional octahedral hexapod design has a very limited workspace, though free of singularities. There are important deviations between the actual and the specified kinematic model in a commercial motion base. Practical implications-A commercial motion base can be used as a precision positioning device with its controller retrofit-ted with state-of-the-art motion control technology with accurate workspace and geometric characteristics. Originality/value-A novel geometric approach for obtaining meaningful measures of the workspace is proposed. A novel, systematic procedure for the calibration of a hexapod is outlined. Finally, experimental results are presented and discussed

Stochastic modelling of African swine fever in wild boar and domestic pigs: epidemic forecasting and comparison of disease management strategies

African swine fever (ASF), caused by the African swine fever virus (ASFV), is highly virulent in domestic pigs and wild boar (Sus scrofa), causing up to 100% mortality. The recent epidemic of ASF in Europe has had a serious economic impact and poses a threat to global food security. Unfortunately, there is no effective treatment or vaccine against ASFV, limiting the available disease management strategies. Mathematical models allow us to further our understanding of infectious disease dynamics and evaluate the efficacy of disease management strategies. The ASF Challenge, organised by the French National Research Institute for Agriculture, Food, and the Environment, aimed to expand the development of ASF transmission models to inform policy makers in a timely manner. Here, we present the model and associated projections produced by our team during the challenge. We developed a stochastic model combining transmission between wild boar and domestic pigs, which was calibrated to synthetic data corresponding to different phases describing the epidemic progression. The model was then used to produce forward projections describing the likely temporal evolution of the epidemic under various disease management scenarios. Despite the interventions implemented, long-term projections forecasted persistence of ASFV in wild boar, and hence repeated outbreaks in domestic pigs. A key finding was that it is important to consider the timescale over which different measures are evaluated: interventions that have only limited effectiveness in the short term may yield substantial long-term benefits. Our model has several limitations, partly because it was developed in real-time. Nonetheless, it can inform understanding of the likely development of ASF epidemics and the efficacy of disease management strategies, should the virus continue its spread in Europe

Low Speed Automation, a French Initiative

Nowadays, vehicle safety is constantly increasing thanks to the improvement of vehicle passive and active safety. However, on a daily usage of the car, traffic jams remains a problem. With limited space for road infrastructure, automation of the driving task on specific situation seems to be a possible solution. The French project ABV, which stands for low speed automation, tries to demonstrate the feasibility of the concept and to prove the benefits. In this article, we describe the scientific background of the project and expected outputs. Comment: TRA (2012) Document type: Conference objec

Blasts in context:the impact of the immune environment on acute myeloid leukemia prognosis and treatment

Acute myeloid leukemia (AML) is a cancer that originates from the bone marrow (BM). Under physiological conditions, the bone marrow supports the homeostasis of immune cells and hosts memory lymphoid cells. In this review, we summarize our present understanding of the role of the immune microenvironment on healthy bone marrow and on the development of AML, with a focus on T cells and other lymphoid cells. The types and function of different immune cells involved in the AML microenvironment as well as their putative role in the onset of disease and response to treatment are presented. We also describe how the immune context predicts the response to immunotherapy in AML and how these therapies modulate the immune status of the bone marrow. Finally, we focus on allogeneic stem cell transplantation and summarize the current understanding of the immune environment in the post-transplant bone marrow, the factors associated with immune escape and relevant strategies to prevent and treat relapse.</p