Flight Dynamics Operations of the TanDEM-X Formation

Since end of 2010 the German TerraSAR-X and TanDEM-X satellites are routinely operated as the first configurable single-pass Synthetic Aperture Radar interferometer in space. The two 1340 kg satellites fly in a 514 km sun-synchronous orbit. In order to collect sufficient measurements for the generation of a global digital elevation model and to demonstrate new interferometric SAR techniques and applications, more than three years of formation flying are foreseen with flexible baselines ranging from 150 m to few kilometers. As a prerequisite for the close formation flight an extensive flight dynamics system was established at DLR/GSOC, which comprises of GPS-based absolute and relative navigation and impulsive orbit and formation control. Daily formation maintenance maneuvers are performed by TanDEM-X to counterbalance natural and artificial disturbances. The paper elaborates on the routine flight dynamics operations and its interactions with mission planning and ground-station network. The navigation and formation control concepts and the achieved control accuracy are briefly outlined. Furthermore, the paper addresses non-routine operations experienced during formation acquisition, frequent formation reconfiguration, formation maintenance problems and space debris collision avoidance, which is even more challenging than for single-satellite operations. In particular two close approaches of debris are presented, which were experienced in March 2011 and April 2012. Finally, a formation break-up procedure is discussed which could be executed in case of severe onboard failures

Acute on Chronic Pancreatitis Causing a Highway to the Colon with Subsequent Road Closure: Pancreatic Colonic Fistula Presenting as a Large Bowel Obstruction Treated with Pancreatic Duct Stenting

Context. Colonic complications associated with acute pancreatitis have a low incidence but carry an increased risk of mortality with delayed diagnosis and treatment. Pancreatic colonic fistula is most commonly associated with walled off pancreatic necrosis or abscess formation and rarely forms spontaneously. Classic clinical manifestations for pancreatic colonic fistula include diarrhea, hematochezia, and fever. Uncommonly pancreatic colonic fistula presents as large bowel obstruction.Case. We report a case of a woman with a history of recurrent episodes of acute pancreatitis who presented with large bowel obstruction secondary to pancreatic colonic fistula. Resolution of large bowel obstruction and pancreatic colonic fistula was achieved with pancreatic duct stenting.Conclusion. Pancreatic colonic fistula can present as large bowel obstruction. Patients with resolved acute pancreatitis who have radiographic evidence of splenic flexure obstruction, but without evidence of mechanical obstruction on colonoscopy, should be considered for ERCP to evaluate for PCF. PCF not associated with walled off pancreatic necrosis or peritoneal abscess can be treated conservatively with pancreatic duct stenting.</jats:p

The technique and imagery of Yuan san-ch'u.

In the following analysis of forty-six songs I have attempted to describe the genre of san-ch'u as it was practised by writers of the Yuan Dynasty. To accomplish this I felt the most significant points were technique of composition and the manner in which it produced effective imagery. Although critical appraisal is an inevitable part of any analysis, here it is used as often to shed light on the appreciation of a song within the original circum-stances of its composition and performance as it is to make general comparisons with other poetry. I felt it legitimate to praise songs that are interesting as poems but have usually qualified any criticism of those that are not good by modern critical standards because it is often our lack of essential information, specifically the music to which it was written, that makes some san-ch'u appear mediocre to us now. To have judged the songs solely as poetry would have given a distorted view of the genre as it existed in the Yuan Dynasty. In every way as essential as the description of san-ch'u is the need to outline certain aspects of poetic composition that are characteristic of san-ch'u and Chinese poetry in general, aspects that a Chinese reader is able to take for granted but without an understanding of which a foreign student of Chinese poetry can hardly progress beyond the meanings of words alone. Although a great share of the work has taken the form of studies in technique, i.e. metre, rhyme, colour, repetition patterning and figuration, I have aimed at seeking out and remarking on the poetic effects and imagery that the various techniques are able to produce

Surgical Intervention Compared to Physical Therapy for Treating Femoroacetabular Impingement: A Systematic Review

Objective: To review published research regarding hip surgery versus physical therapy in treating femoroacetabular impingement (FAI). Methods: The literature was obtained from PubMed, CINAHL, and Google Scholar. These sources were assessed for outcomes pertaining to FAI post-intervention. The interventions included hip arthroscopy surgery and physical therapy led care. Results: The literature reviewed suggested that both physical therapy and arthroscopy improved overall hip quality of life in patients with FAI. However, some studies found that arthroscopy had statistically significant greater outcomes than physical therapy. These interventions proved to both be beneficial to patients who had FAI. Conclusion: The use of either physical therapy or hip arthroscopy surgery to treat FAI are considered adequate, however some studies suggest that surgery provides quicker and superior results compared to physical therapy. Due to the inconclusive nature and newness of this issue, these interventions should be studied further

Eine qualitative Studie: der individuelle Umgang mit Problemen in den Lebenswelten von Schülern und Schülerinnen mit Lernbehinderungen

Bei Beobachtungen in der beruflichen Praxis wurde deutlich, dass Schüler (und Schülerin-nen) und Lehrer (und Lehrerinnen) oftmals im Unterricht gegenseitig ihre Handlungen in Frage stellen. Diese Infragestellungen werden unter Anderem als 'Unterrichtsstörungen' beschrieben. Auf dem Hintergrund des leitenden Menschenbildes des Radikalen Konstruk-tivismus (von Glasersfeld), des Sozialen Konstruktionismus (Gergen) und der These, dass ein adäquater Einbezug der Schülerpersönlichkeiten in das Unterrichtsgeschehen Unter-richtsstörungen und kommunikative Missverständnisse verringern können und der indivi-duelle Lernerfolg ansteigen kann, wurde die Frage gestellt, wie ein Einbezug von Schülern und Schülerinnen mit Lernbehinderungen in die Themen- und Zielvorstellungen von Un-terricht aussehen könnte.Ausgehend von einem konstruktivistisch-systemischen Verständnis über 'Lernbehinderun-gen' (Werning und Schmetz) sowie basierend auf der Prämisse, dass über die Teilhabe an Alltagserfahrungen in den individuellen Lebenswelten der Schüler und Schülerinnen Rück-schlüsse über die Bedürfnisse, und auch über die vorhandenen Kompetenzen zur Nutzung bei der Planung und Durchführung von Unterricht möglich sind, wurde im Rahmen der Modernitätstheoretischen Kinderforschung unter Hinzuziehung von Elementen der Bio-graphieforschung und den Ausführungen über sozialrandständige, armutsgefährdete Kinder als methodischer Weg die (erweiterte) Einzelfallstudie unter Verwendung des Narrativen Interviews und der Teilnehmenden Beobachtung gewählt, um wissenschaftliche Erkennt-nisse zu erlangen.Über die verschiedenen Analyseschritte der Auswertungsmethode des Zirkulären De-konstruierens von Jaeggi u.a. (1998) kristallisierte sich 'die individuelle Problembewälti-gung in den Bereichen der verbalen Kommunikation und der Nutzung von Problemlöse-strategien als allen Jugendlichen gemeinsame Herausforderung ihres alltäglichen Lebens' (Schlepp-Pellny 2003, 15) heraus.Die Analyse des individuellen Umgangs mit Problemen von drei Jugendlichen 'mit Lern-behinderungen' zeigte auf, welche Inhalte, Begegnungen, Gespräche usw. den Jugendlichen subjektiv bedeutsam waren, welche Kompetenzen sie im Umgang mit individuellen Prob-lemen aufweisen konnten und in welchen Bereichen (u.a. insbesondere im Bereich der problemorientierten verbalen Argumentation und der Empathiefähigkeit) Förderbedarf bestand.Aus den ermittelten Informationen wurde, ausgehend von der Vorstellung, dass Lehrper-sonen eine besondere Verantwortung für das Gelingen von unterrichtlichen Vorstellungen und Zielen sowie für die den Unterricht begleitenden und begründenden sozialen Bedürf-nisse haben, ein Anforderungsprofil für den Unterricht in der Schule für Lernbehinderte erstellt. Darüber hinaus wurde auf der Basis des Unterrichtsprinzips zum vollständigen Lernen nach Peterßen (1999) das Modell des Kompetenzgeleiteten Unterrichts (KGU) ent-wickelt. Als Beleg zur Umsetzbarkeit des KGU schließt die Arbeit mit exemplarischen Unterrichtsbausteinen, welche den Einbezug der Schülerkompetenzen einerseits und die Förderbedürfnisse andererseits gewährleisten und demonstrieren. Bei der Beschreibung der angestrebten Förderziele wurden im zweiten Teil der vorliegenden Dissertation wesentli-che Prinzipien der sonderpädagogischen Theorie und Praxis (u.a.: Auswahl von lebensbe-deutsamen Themen und Zielen, didaktische Reduktion, Differenzierung) begründet und berücksichtigt. Alle Analyseschritte, die zur Entstehung der Dissertation und ihrer Ergebnisse beigetragen haben und nicht im Hauptteil der Dissertation abgedruckt sind, sind im dritten Teil der Studie (Anhang) aufgeführt

Uptake of moss‐derived human recombinant GAA in Gaa−/− mice

Pompe disease, an autosomal recessive lysosomal storage disorder, is caused by deficiency of lysosomal acid alpha-glucosidase (GAA). On cellular level, there is lysosomal-bound and free accumulation of glycogen and subsequent damage of organelles and organs. The most severe affected tissues are skeletal muscles and heart. The only available treatment to date is an enzyme replacement therapy (ERT) with alglucosidase alfa, a recombinant human GAA (rhGAA) modified with mannose-6-phosphate (M6P), which is internalized via M6P-mediated endocytosis. There is an unmet need to improve this type of therapy, especially in regard to skeletal muscle. Using different tissue culture models, we recently provided evidence that a moss-derived nonphosphorylated rhGAA (moss-GAA), carrying a glycosylation with terminal N-acetylglucosamine residues (GnGn), might have the potential to improve targeting of skeletal muscle. Now, we present a pilot treatment of Gaa−/− mice with moss-GAA. We investigated general effects as well as the uptake into different organs following short-term treatment. Our results do confirm that moss-GAA reaches the target disease organs and thus might have the potential to be an alternative or complementary ERT to the existing one

Flight Dynamics Experience on Target Orbit Acquisition and Maintenance Operations for Germany's Hyperspectral Satellite Mission EnMAP

The Environmental Mapping and Analysis Program (EnMAP) is a German hyperspectral satellite mission that aims at monitoring and characterizing Earth's environment on a global scale. The satellite was successfully launched with SpaceX's Falcon 9 Transporter-4 mission on April 1st, 2022. This paper elaborates on the in-flight results obtained during the EnMAP Launch and Early-Operations Phase (LEOP) and the first months of the commissioning phase. Besides the flight dynamics operations, this paper addresses the repeat ground-track orbit control concept and discusses novel flight dynamics functionalities implemented to optimize the scientific return of the EnMAP mission, such as microservices for fast data exchange between the flight dynamics and mission planning systems

Moss-produced human complement factor H with modified glycans has an extended half-life and improved biological activity

Most drugs that target the complement system are designed to inhibit the complement pathway at either the proximal or terminal levels. The use of a natural complement regulator such as factor H (FH) could provide a superior treatment option by restoring the balance of an overactive complement system while preserving its normal physiological functions. Until now, the systemic treatment of complement-associated disorders with FH has been deemed unfeasible, primarily due to high production costs, risks related to FH purified from donors’ blood, and the challenging expression of recombinant FH in different host systems. We recently demonstrated that a moss-based expression system can produce high yields of properly folded, fully functional, recombinant FH. However, the half-life of the initial variant (CPV-101) was relatively short. Here we show that the same polypeptide with modified glycosylation (CPV-104) achieves a pharmacokinetic profile comparable to that of native FH derived from human serum. The treatment of FH-deficient mice with CPV-104 significantly improved important efficacy parameters such as the normalization of serum C3 levels and the rapid degradation of C3 deposits in the kidney compared to treatment with CPV-101. Furthermore, CPV-104 showed comparable functionality to serum-derived FH in vitro , as well as similar performance in ex vivo assays involving samples from patients with atypical hemolytic uremic syndrome, C3 glomerulopathy and paroxysomal nocturnal hematuria. CPV-104 – the human FH analog expressed in moss – will therefore allow the treatment of complement-associated human diseases by rebalancing instead of inhibiting the complement cascade

ATTITUDE CONTROL on GRACE FOLLOW-ON Experiences from the first years in orbit

The two satellites for the GRACE* Follow-on mission were successfully launched in May 2018 on a polar orbit at an altitude of 491 km. The mission continues the measurements of the gravity field of the Earth (with emphasis on the time variability) and also delivers radio occultation measurements. The twin satellites are kept at a relative distance of 170 to 270 km and act as probes in the gravity field of the Earth. The inter-satellite distance is measured by a microwave tracking system to an accuracy of 1 μm. A laser ranging interferometer is added as a technology demonstration. Stable and accurate relative pointing, as well as the minimization of disturbance torques, is required in order to optimize scientific results. This poses stringent demands upon attitude control. The performance of the GRACE Follow-on attitude control system will be presented, as well as the special actions and changes that became necessary as the mission evolved. A short description of the sensors and actuators used for attitude control is given and improvements with respect to GRACE are discussed in some more detail. The operational modes are described with a focus on the so-called nominal fine-pointing mode, in which the front-ends point towards each other in order to enable microwaveand laser-ranging. The third Section opens with a description of special tasks, such as the fine-tuning of the control and monitoring parameters and the complex determination of the satellite’s center of gravity. A comparison is made with a tracking model based upon the fuel expenditure from the two tanks that can be determined independently. Several series of involved tests with manual thruster firings were performed in order to characterize the response of the accelerometers to thruster actuations. A description of the design of the tests, their execution and results is presented. A switch to the redundant instrument was made five months after launch on one of the satellites. The consequences for attitude control are discussed in Section 4. A method that was developed to cope with a situation where also the redundant GPS receiver would become unavailable is discussed in detail. Conclusions and an outlook for the upcoming years of operations are presented in the last Section