Design and commissioning of a transportable laser ranging station STAR-C

A fast growing population of nano- and mirco satellites, space debris, as well as plans of installing mega constellations drives the demand for the development of new ground stations technologies. The Institute of Technical Physics of the German Aerospace Center (DLR) focuses its research on optical methods in order to track and range orbital objects for precise orbit determination. Laser ranging is an inherently accurate method to determine an object’s distance where sub-mm accuracy is achieved by the contributing stations within the International Laser Ranging Service (ILRS). Usually the orbits of space debris are determined with radar based observations and maintained in catalogues, for example the TLE data by NORAD. Multiple optical ground stations can contribute significantly to support catalogue maintenance or to refine orbits of particular orbital objects. Laser ranging data does not only measure the slant range to an object, but also can give rise to the state of propagation, if the single shot accuracy of the laser pulse is shorter than the apparent dimension of the object. Currently there is work in progress to build a transportable laser ranging station into a standard 20ft ISO container, which takes up its initial operation during the second half of this year. A platform raises two telescopes in a bi-static set-up on an alt-az mout above the roof of the container. Each axis of the alt-az mount is driven with direct mounts, where absolute encoders give a theoretical angular resolution of 1/50 arcsec. One telescope with an aperture of 10cm is used for the transmit channel of a pulsed infrared laser an including active beam stabilization. The other telescope, the receive channel, with an aperture of 43cm a beam-splitter separates the visible light on a camera for tracking and the infrared light on a fiber-coupled single photon detector for ranging

CID Survey Report Satellite Imagery and Associated Services used by the JRC. Current Status and Future Needs

The Agriculture and Fisheries Unit (IPSC) together with the Informatics, Networks and Library Unit (ISD) has performed this inventory called the Community Image Data portal Survey (the CID Survey); 20 Actions from 4 different Institutes (ISD, IPSC, IES, and IHCP) were interviewed. The objectives of the survey were to make an inventory of existing satellite data and future requirements; to obtain an overview of how data is acquired, used and stored; to quantify human and financial resources engaged in this process; to quantify storage needs and to query the staff involved in image acquisition and management on their needs and ideas for improvements in view of defining a single JRC portal through which imaging requests could be addressed. Within the JRC there are (including 2006) more than 700 000 low resolution (LR) and 50 000 medium resolution (MR) images, with time series as far back as 1981 for the LR data. There are more than 10 000 high resolution (HR) images and over 500 000 km2 of very high resolution (VHR) images. For the LR and MR data, cyclic global or continental coverage dominates, while the majority of HR and VHR data is acquired over Europe. The expected data purchase in the future (2007, 2008) known which enables good planning. Most purchases of VHR and HR data are made using the established FCs with common licensing terms. Otherwise multiple types of licensing govern data usage which emphasizes the need for CID to establish adequate means of data access. The total amount of image data stored (2006 inclusive) is 55 TB, with an expected increase of 80% in 2 years. Most of the image data is stored on internal network storage inside the corporate network which implies that the data is accessible from JRC, but difficulties arise when access is to be made by external users via Internet. In principle current storage capacity in the JRC could be enough, but available space is fragmented between Actions which therefore implies that a deficit in storage could arise. One solution to this issue is the sharing of a central storage service. Data reception is dominated by FTP data transfer which therefore requires reliable and fast Internet transfer bandwidth. High total volume for backup requires thorough definition of backup strategy. The user groups at JRC are heterogeneous which places requirements on CID to provide flexible authentication mechanisms. There is a requirement for a detailed analysis of all metadata standards needed for reference in a catalogue. There is a priority interest for such Catalogue Service and also for a centralized storage. The services to implement for data hosted on central storage should be WCS, WMS, file system access. During the analysis of the results mentioned above, some major areas could be identified as a base for common services to be provided to interested Actions, such as: provision of a centralized data storage facility with file serving functionality including authentication service, image catalogue services, data visualization and dissemination services. Specialized data services that require highly customized functionality with respect to certain properties of the different image types will usually remain the sole responsibility of the individual Actions. An orthorectification service for semi-automated orthorectification of HR and VHR data will be provided to certain Actions. At the end of the report some priorities and an implementation schedule for the Community Image Data portal (CID) are given.JRC.G.3-Agricultur

Si « de picart en franczoys » : de l’ancien au moyen français

Il est rare qu’un écrivain médiéval d’oïl émette un jugement de nature linguistique sur son parler maternel ; plus rare encore qu’un copiste fasse état de ses réflexions sur la variété langagière du modèle qu’il a sous les yeux, en tant qu’elle diffère de la sienne (sauf à se défausser sur l’imperfection de celui-ci des bourdes que lui-même pourrait commettre ; encore est-ce, dans ce cas, la défectuosité du texte qui est mise en cause, non l’insuffisance de l’instrument linguistique). Il est ..

Abgehängt im Aufschwung: Demografie, Arbeit und rechter Protest in Ostdeutschland

Es erscheint paradox: Die Arbeitslosigkeit in Deutschland erreichte vor der Corona-Krise ein historisches Tief, die Wirtschaft feierte Exportrekorde. Dennoch hat der Boom viele Menschen nicht erreicht. Gerade in strukturschwachen Regionen und Städten ist dieser Widerspruch ausgeprägt. Diese Orte gelten als abgehängt, aufgrund des Bevölkerungsrückgangs zeichnet sich keine Verbesserung der Situation ab. Im Leben vieler Menschen macht sich Unzufriedenheit breit. Angesichts niedriger Entlohnung und mangelnder Mitsprachemöglichkeiten am Arbeitsplatz radikalisieren sich Ungerechtigkeitsempfindungen. Die empirische Studie nimmt diese Dynamiken am Beispiel Ostthüringens, einer strukturschwachen und schrumpfenden Region, in den Blick

Experiencia en el uso de una plataforma digital para el ejercicio de la comprensión lectora y el vocabulario: percepción de estudiantes de primaria

This study explores the experience of using a digital platform for reading comprehension and vocabulary based on the perception of students in Chilean elementary education. 493 surveys completed by students in 3rd, 4th, 5th and 6th grade from private subsidized schools were analyzed. The survey responses are complemented with answers from a focus group with 17 students in the same classrooms. The results indicate that the majority of students positively perceive the use of the platform, indicating that it was an aid to improve their reading comprehension. From the students' responses, categories are created that describe their perceptions. Implications for educational research and practice are discussed.Este estudio explora la experiencia de uso de una plataforma digital para ejercitar comprensión lectora y vocabulario según las percepciones de alumnos de enseñanza básica. Se analizaron 493 encuestas aplicadas a estudiantes chilenos de 3º, 4º, 5º y 6º básico de establecimientos subvencionados. Las encuestas son complementadas con respuestas obtenidas en un grupo focal con 17 estudiantes de los mismos cursos. Los resultados indican que la mayor parte de los encuestados perciben positivamente el uso de la plataforma, indicando que fue una ayuda para mejorar su comprensión lectora. A partir de las respuestas, se crean categorías que describen la percepción de ellos. Se discuten implicancias para la investigación y práctica educativa. &nbsp

Experiencia en el uso de una plataforma digital para el ejercicio de la comprensión lectora y el vocabulario: percepción de estudiantes de primaria

Este estudio explora la experiencia de uso de una plataforma digital para ejercitar comprensión lectora y vocabulario según las percepciones de alumnos de enseñanza básica. Se analizaron 493 encuestas aplicadas a estudiantes chilenos de 3º, 4º, 5º y 6º básico de establecimientos subvencionados. Las encuestas son complementadas con respuestas obtenidas en un grupo focal con 17 estudiantes de los mismos cursos. Los resultados indican que la mayor parte de los encuestados perciben positivamente el uso de la plataforma, indicando que fue una ayuda para mejorar su comprensión lectora. A partir de las respuestas, se crean categorías que describen la percepción de ellos. Se discuten implicancias para la investigación y práctica educativa.&nbsp

Higher-Order Chromatin Structures of Chromosomally Integrated HHV-6A Predict Integration Sites

Human herpesvirus -6A and 6B (HHV-6A/B) can integrate their genomes into the telomeres of human chromosomes. Viral integration can occur in several cell types, including germinal cells, resulting in individuals that harbor the viral genome in every cell of their body. The integrated genome is efficiently silenced but can sporadically reactivate resulting in various clinical symptoms. To date, the integration mechanism and the subsequent silencing of HHV-6A/B genes remains poorly understood. Here we investigate the genome-wide chromatin contacts of the integrated HHV-6A in latently-infected cells. We show that HHV-6A becomes transcriptionally silent upon infection of these cells over the course of seven days. In addition, we established an HHV-6-specific 4C-seq approach, revealing that the HHV-6A 3D interactome is associated with quiescent chromatin states in cells harboring integrated virus. Furthermore, we observed that the majority of virus chromatin interactions occur toward the distal ends of specific human chromosomes. Exploiting this finding, we established a 4C-seq method that accurately detects the chromosomal integration sites. We further implement long-read minION sequencing in the 4C-seq assay and developed a method to identify HHV-6A/B integration sites in clinical samples

Precise short- and long-term propagation of orbits and uncertainties using the Hermite integration scheme for LEO space debris objects

The Institute of Technical Physics of the German Aerospace Center (DLR) is actively developing laser-based optical tracking methods to determine 3D positions of LEO space debris objects to within 10 metres to support several SSA-related use cases, e.g. conjunction assessment, maneuver detection, or analysis of re-entry events. For the purpose of precise orbit determination and the subsequent propagation of states and their uncertainties, an accurate, fast, and versatile integration method is needed. We will present a numerical integration technique based on the Hermite scheme, a self-starting, implicite predictor-corrector method originally developed and widely used for gravitational N-body systems. The Hermite scheme uses the acceleration and its first time derivative to predict future position and velocity vectors from previous values. The gist of the method relies on the fact that the second and third derivatives can be explicitly calculated from the acceleration and its first derivative alone. These are then used iteratively to correct the object's state vector, yielding an integration method with fourth-order global error. The method can be used with constant or variable timesteps. In the case of constant timesteps, the Hermite integrator is time-symmetric and shows no secular error in the semi-major axis and eccentricity, which makes the integrator extremely useful for long-term dynamical simulations. The code can integrate an ensemble of objects in parallel, with either shared or individual timesteps. It can therefore be applied to propagate a catalogue of space objects and/or to perform realistic uncertainty propagation via Monte-Carlo or sigma-point methods. We will show current results from our orbit propagator development which is geared towards LEO space debris objects and discuss the implementation of the force model

Mirour de Seinte Eglyse (St. Edmund of Abingdon's Speculum Ecclesiae), ed. by A. D. Wilshere, 1982

Hasenohr Geneviève. Mirour de Seinte Eglyse (St. Edmund of Abingdon's Speculum Ecclesiae), ed. by A. D. Wilshere, 1982. In: Romania, tome 106 n°423-424, 1985. pp. 539-545