Characterization of putatively connected cells to different retinal ganglion cell terminals in the zebrafish brain

Diese Arbeit beschäftigt sich mit der anatomischen Untersuchung der Neuronen die im neuronalen Netzwerks des Opto-Motor-Reflexes eine Rolle spielen, welches verantwortlich ist für die Umsetzung von visuellem Input in Bewegungsmuster. Zu diesem Zweck werden Zebrafischlarven verwendet, die ein sehr gutes Modellsystem für das Entschlüsseln des visuellen Verhaltens und den zugrunde liegenden Nervenzellen bieten. Eine Reaktion auf visuelle Stimuli kann sobald Axone von retinalen Ganglienzellen ihre postsynaptischen Ziele erreichen, beobachtet werden. Am anderen Ende des neuronalen Netzwerks sitzen Zellen, die ihre Axone in die Wirbelsäule senden. Diese Nervenzellen sind verantwortlich für die Bewegungsmuster (Schwimm – und Dreh-Bewegungen) welche dem Opto-Motor Reflex zu Grunde liegen. Die Nervenzellen, die sich im Tectum und Pretectum zwischen der Retina und den Zellen befinden, die in die Wirbelsäule projizieren, sind bis jetzt unbekannt. Meine Diplomarbeit zeigt auf, dass mehrere Kandidaten dieser tectalen und pretectalen Nervenzellen möglicherweise in dem bis jetzt noch nicht entschlüsselten Opto-Motor Reflex involviert sind. Durch Photoaktivierung von photoaktivierbarem GFP in den Bereichen, die von mir genetisch markierten Ganglienzellen oder anders markierte Wirbelsäul-projizierende Zellen innervieren, beschreibe ich die Anatomie einer Population von Neuronen, die sich im Tectum und Pretectum befindet. Diese Arbeit versucht zu klären, wie viele und welche Zellen mit den axonalen Enden der genetisch markierten Ganglienzellen verbunden sind. Um eine vollständige Aufschlüsselung der Funktionaltiät dieses Netzwerks zu erhalten, sind weitere Versuche nötig, die diese von mir mittels genetischer Markierung und Photoaktivierung identifzierten pretectalen und tectalen Kandidaten auf ihre Aktivität innerhalb des Opto-Motor-Reflexes testen.As described in this thesis, I studied the neuronal pathway that underlies a certain visuomotor transformation, the optomotor response, by anatomically characterizing the cells involved. My approach uses the larval zebrafish, an attractive model system for identifying the components of neural circuits. Visually induced behaviors emerge as soon as axons of retinal ganglion cells (RGCs), reach their postsynaptic targets. At the other end of the circuit, there are distinct subsets of spinal projection neurons that are responsible for directing motor output (swims and turns) that constitute an essential visual response to whole-field motion. The intermediate circuit, i.e. cells in the tectum or pretectum, is still unknown. To this end my diploma thesis will show putative candidate cells that might be the missing link in this complete circuit. Employing photoactivation of the panneuronaly expressed photoactivateable GFP in specific regions innervated by genectically labeled RGC axons or spinal projection neurons, I was able to describe cells “in-between” in the pretectum and tectum. This study is a first approach to demonstrate how many and which cells are connected to different arborization fields of genetically labeled RGCs, and which of them relay the processed information downstream to spinal projection neurons. To get a complete picture of the functionality of the connections underlying the visuomotor circuit, it will be necessary to study the output of these genetically labeled RGCs and the responses of the candidate cells identified within this thesis, by calcium imaging

Suborbital autorotation landing demonstrator on REXUS 29

Current developments in the aerospace industry point towards more frequent interplanetary travel in the future. However, the main focus of developments is on launcher technology, yet the descent of interplanetary probes is of high importance for the success of future missions. Additionally, to the present landing approaches using either a powered descent requiring fuel or a combination of different parachutes, a third method is investigated in this project. The chosen approach is called autorotation and is commonly used in helicopters. When a helicopter suffers a loss of power, it can still land and even choose its landing site without the utilization of an engine. Similar to parachutes, the presented technology can be applied to various atmospheric conditions by modification of rotor and control parameters. Moreover, a rotor in autorotation can provide directional control and thus the choice of a landing site, which is not feasible using a parachute. All these factors make autorotation an interesting option as an entry descent and landing (EDL) technology for interplanetary missions. Our project, Daedalus 2 implements the autorotation landing strategy as part of the REXUS student project campaign under DLR / ESA / SNSA supervision. Since 2018 we are developing the SpaceSeed Mk.2, a technology demonstrator that incorporates a rotor and all necessary technological means to perform an autorotation EDL maneuver from an apogee of 80 km. The mission concept is laid out within the presented paper. This includes the main challenges like miniaturization of the SpaceSeed v2 due to the size constraints of the REXUS rocket or the used sensors for height and position determination. The importance of a technology demonstrator tested on a sounding rocket to prove the feasibility of our presented system is laid out in our publication. Furthermore, the custom development of electrical, mechanical and software sub systems is discussed. Additionally, the planned mission profile will be explained, including flight phases and different activities conducted by the SpaceSeeds during flight. Moreover, the main differences and improvements to Daedalus 1 are being discusse

The European architectural sector. A scientific perspective on the debate about the economic impact of different regulatory approaches in the Member States of the EU. Aktualisierte Version

The EU Commission – in line with its mandate given by the member states – places an emphasis on the enhancement of the internal market for services. Through further harmonization of the so-called regulated professions, the EU Commission intends to intensify the competition and simplify and strengthen the cross-border provision of services. The architectural profession belongs to this group of regulated professions. All Member States want to ensure a certain minimum quality in the field of architectural services via regulative market interventions. The reason for these market interventions is to ensure the protection of public interests – such as construction safety, consumer and environmental protection as well as cultural, historical, and artistic concerns. According to the EU Commission, such regulation hinders the internal market for services. Whilst the Commission does not urge the abolition of all regulation concerning the area of profession, it does call for a stronger harmonisation of the member states’ own relevant provisions. In order to pursue this aim, the EU Commission has recently recommended an array of measures. This research report analyses the economic observations and theses of the European Commission which state a further need for reforms in the European architectural sector

Electronics and Sensor Subsystem Design for Daedalus 2 on REXUS 29: An Autorotation Probe for Sub-Orbital Re-Entry

The Daedalus 2 mission aboard REXUS 29 is a technology demonstrator for an alternative descent mechanism for very high altitude drops based on auto-rotation. It consists of two probes that are ejected from a sounding rocket at an altitude of about 80 km and decelerate to a soft landing using only a passive rotor with pitch control. This type of autonomous, scientific experiment poses great challenges upon the electronics subsystem, which include mechanical stress, power system reliability, sensor redundancy, subsystem communication, and development procedures. Based on the data gathered in Daedalus 1 multiple new approaches were developed to fulfill these requirements, such as redundant communication links, mechanical decoupling of PCBs and fault-tolerant power source selection.Comment: 8 pages, 10 figure

The European architectural sector. A scientific perspective on the debate about the economic impact of different regulatory approaches in the Member States of the EU

The EU Commission – in line with its mandate given by the member states – places an emphasis on the enhancement of the internal market for services. Through further harmonization of the so-called regulated professions, the EU Commission intends to intensify the competition and simplify and strengthen the cross-border provision of services. The architectural profession belongs to this group of regulated professions. All Member States want to ensure a certain minimum quality in the field of architectural services via regulative market interventions. The reason for these market interventions is to ensure the protection of public interests – such as construction safety, consumer and environmental protection as well as cultural, historical, and artistic concerns. According to the EU Commission, such regulation hinders the internal market for services. Whilst the Commission does not urge the abolition of all regulation concerning the area of profession, it does call for a stronger harmonisation of the member states’ own relevant provisions. In order to pursue this aim, the EU Commission has recently recommended an array of measures. This research report analyses the economic observations and theses of the European Commission which state a further need for reforms in the European architectural sector

The genetic study of three population microisolates in South Tyrol (MICROS): study design and epidemiological perspectives

<p>Abstract</p> <p>Background</p> <p>There is increasing evidence of the important role that small, isolated populations could play in finding genes involved in the etiology of diseases. For historical and political reasons, South Tyrol, the northern most Italian region, includes several villages of small dimensions which remained isolated over the centuries.</p> <p>Methods</p> <p>The MICROS study is a population-based survey on three small, isolated villages, characterized by: old settlement; small number of founders; high endogamy rates; slow/null population expansion. During the stage-1 (2002/03) genealogical data, screening questionnaires, clinical measurements, blood and urine samples, and DNA were collected for 1175 adult volunteers. Stage-2, concerning trait diagnoses, linkage analysis and association studies, is ongoing. The selection of the traits is being driven by expert clinicians. Preliminary, descriptive statistics were obtained. Power simulations for finding linkage on a quantitative trait locus (QTL) were undertaken.</p> <p>Results</p> <p>Starting from participants, genealogies were reconstructed for 50,037 subjects, going back to the early 1600s. Within the last five generations, subjects were clustered in one pedigree of 7049 subjects plus 178 smaller pedigrees (3 to 85 subjects each). A significant probability of familial clustering was assessed for many traits, especially among the cardiovascular, neurological and respiratory traits. Simulations showed that the MICROS pedigree has a substantial power to detect a LOD score ≥ 3 when the QTL specific heritability is ≥ 20%.</p> <p>Conclusion</p> <p>The MICROS study is an extensive, ongoing, two-stage survey aimed at characterizing the genetic epidemiology of Mendelian and complex diseases. Our approach, involving different scientific disciplines, is an advantageous strategy to define and to study population isolates. The isolation of the Alpine populations, together with the extensive data collected so far, make the MICROS study a powerful resource for the study of diseases in many fields of medicine. Recent successes and simulation studies give us confidence that our pedigrees can be valuable both in finding new candidates loci and to confirm existing candidate genes.</p

Calathus: A sample-return mission to Ceres

Ceres, as revealed by NASA's Dawn spacecraft, is an ancient, crater-saturated body dominated by low-albedo clays. Yet, localised sites display a bright, carbonate mineralogy that may be as young as 2 Myr. The largest of these bright regions (faculae) are found in the 92 km Occator Crater, and would have formed by the eruption of alkaline brines from a subsurface reservoir of fluids. The internal structure and surface chemistry suggest that Ceres is an extant host for a number of the known prerequisites for terrestrial biota, and as such, represents an accessible insight into a potentially habitable “ocean world”. In this paper, the case and the means for a return mission to Ceres are outlined, presenting the Calathus mission to return to Earth a sample of the Occator Crater faculae for high-precision laboratory analyses. Calathus consists of an orbiter and a lander with an ascent module: the orbiter is equipped with a high-resolution camera, a thermal imager, and a radar; the lander contains a sampling arm, a camera, and an on-board gas chromatograph mass spectrometer; and the ascent module contains vessels for four cerean samples, collectively amounting to a maximum 40 g. Upon return to Earth, the samples would be characterised via high-precision analyses to understand the salt and organic composition of the Occator faculae, and from there to assess both the habitability and the evolution of a relict ocean world from the dawn of the Solar System.The attached document is the authors’ final accepted version of the journal article provided here with a Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) Creative Commons Licence. You are advised to consult the publisher’s version if you wish to cite from it.

VELEX: Venus Lightning Experiment

Lightning has fascinated humanity since the beginning of our existence. Different types of lightning like sprites and blue jets were discovered, and many more are theorized. However, it is very likely that these phenomena are not exclusive to our home planet. Venus’s dense and active atmosphere is a place where lightning is to be expected. Missions like Venera, Pioneer, and Galileo have carried instruments to measure electromagnetic activity. These measurements have indeed delivered results. However, these results are not clear. They could be explained by other effects like cosmic rays, plasma noise, or spacecraft noise. Furthermore, these lightning seem different from those we know from our home planet. In order to tackle these issues, a different approach to measurement is proposed. When multiple devices in different spacecraft or locations can measure the same atmospheric discharge, most other explanations become increasingly less likely. Thus, the suggested instrument and method of VELEX incorporates multiple spacecraft. With this approach, the question about the existence of lightning on Venus could be settled

MAPLE: Marsian Autorotation Probe Lander Experiment

The first step towards aerial planetary exploration has been made. Ingenuity shows extremely promising results, and new missions are already underway. Rotorcraft are capable of flight. This capability could be utilized to support the last stages of Entry, Descent, and Landing. Thus, mass and complexity could be scaled down. Autorotation is one method of descent. It describes unpowered descent and landing, typically performed by helicopters in case of an engine failure. MAPLE is suggested to test these procedures and understand autorotation on other planets. In this series of experiments, the Ingenuity helicopter is utilized. Ingenuity would autorotate a ”mid-air-landing” before continuing with normal flight. Ultimately, the collected data shall help to understand autorotation on Mars and its utilization for interplanetary exploration