The science case for the EISCAT_3D radar

The EISCAT (European Incoherent SCATer) Scientific Association has provided versatile incoherent scatter (IS) radar facilities on the mainland of northern Scandinavia (the EISCAT UHF and VHF radar systems) and on Svalbard (the electronically scanning radar ESR (EISCAT Svalbard Radar) for studies of the high-latitude ionised upper atmosphere (the ionosphere). The mainland radars were constructed about 30 years ago, based on technological solutions of that time. The science drivers of today, however, require a more flexible instrument, which allows measurements to be made from the troposphere to the topside ionosphere and gives the measured parameters in three dimensions, not just along a single radar beam. The possibility for continuous operation is also an essential feature. To facilitatefuture science work with a world-leading IS radar facility, planning of a new radar system started first with an EU-funded Design Study (2005–2009) and has continued with a follow-up EU FP7 EISCAT_3D Preparatory Phase project (2010–2014). The radar facility will be realised by using phased arrays, and a key aspect is the use of advanced software and data processing techniques. This type of software radar will act as a pathfinder for other facilities worldwide. The new radar facility will enable the EISCAT_3D science community to address new, significant science questions as well as to serve society, which is increasingly dependent on space-based technology and issues related to space weather. The location of the radar within the auroral oval and at the edge of the stratospheric polar vortex is also ideal for studies of the long-term variability in the atmosphere and global change. This paper is a summary of the EISCAT_3D science case, which was prepared as part of the EU-funded Preparatory Phase project for the new facility. Three science working groups, drawn from the EISCAT user community, participated in preparing this document. In addition to these working group members, who are listed as authors, thanks are due to many others in the EISCAT scientific community for useful contributions, discussions, and support

The science case for the EISCAT_3D radar

The EISCAT (European Incoherent SCATer) Scientific Association has provided versatile incoherent scatter (IS) radar facilities on the mainland of northern Scandinavia (the EISCAT UHF and VHF radar systems) and on Svalbard (the electronically scanning radar ESR (EISCAT Svalbard Radar) for studies of the high-latitude ionised upper atmosphere (the ionosphere). The mainland radars were constructed about 30 years ago, based on technological solutions of that time. The science drivers of today, however, require a more flexible instrument, which allows measurements to be made from the troposphere to the topside ionosphere and gives the measured parameters in three dimensions, not just along a single radar beam. The possibility for continuous operation is also an essential feature. To facilitatefuture science work with a world-leading IS radar facility, planning of a new radar system started first with an EU-funded Design Study (2005–2009) and has continued with a follow-up EU FP7 EISCAT_3D Preparatory Phase project (2010–2014). The radar facility will be realised by using phased arrays, and a key aspect is the use of advanced software and data processing techniques. This type of software radar will act as a pathfinder for other facilities worldwide. The new radar facility will enable the EISCAT_3D science community to address new, significant science questions as well as to serve society, which is increasingly dependent on space-based technology and issues related to space weather. The location of the radar within the auroral oval and at the edge of the stratospheric polar vortex is also ideal for studies of the long-term variability in the atmosphere and global change. This paper is a summary of the EISCAT_3D science case, which was prepared as part of the EU-funded Preparatory Phase project for the new facility. Three science working groups, drawn from the EISCAT user community, participated in preparing this document. In addition to these working group members, who are listed as authors, thanks are due to many others in the EISCAT scientific community for useful contributions, discussions, and support

Biografieforschung: theoretische Perspektiven und methodologische Konzepte für eine re-konstruktive Geschlechterforschung

Die Biografieforschung bezeichnet einen komplexen Forschungsansatz, der auf eine lange Geschichte des wissenschaftlichen Interesses an "persönlichen Dokumenten" verweisen kann. Sie ist eine voraussetzungsvolle Forschungsperspektive, die sich in zentralen Aspekten ihres Vorgehens auf Biografien als theoretisches Konzept, als historisch-empirischen Gegenstand und als komplexe methodologische Strategie bezieht. Andere Begriffe, welche oftmals synonym gebraucht, in der Biografieforschung aber systematisch unterschieden werden, sind "Lebensgeschichte" und "Lebenslauf". Die Autorin skizziert die Perspektiven einer rekonstruktiven Geschlechterforschung innerhalb der Biografieforschung, wozu sie auf die Differenzierungen empirischer Forschung, die methodologischen Prinzipien sowie auf Datenerhebung und Datenanalyse eingeht. Sie hebt insbesondere drei Kontextrelationen bei der Interpretation eines biografischen Textes hervor: Biografie, Interaktion, kulturelle Muster und soziale Regeln. Das skizzierte Konzept von Biografieforschung begreift sie als ein offenes Programm, das vielfältige Anknüpfungspunkte zu aktuellen theoretischen Diskussionen in der Geschlechterforschung aufweist. (ICI2

Mitigation of the Ionospheric Range Error in single-frequency and single-station GNSS applications

A significant number of GNSS applications uses and will continue to use single-frequency GNSS receivers. Therefore the precise estimation of the ionospheric range error from single-frequency GNSS data is and remains to be an important issue. We describe a method which allows to autonomously determine the ionospheric range error using single-frequency GNSS data of a single GNSS receiver. The main idea is not to consider each receiver-satellite link individually, but to use all information present in each epoch and between epochs. For the ionospheric range error there is a non-zero correlation, both between different links at a given time and between links at different times. By taking into account all these correlations, we are able to determine the (absolute) ionospheric range error from single-frequency phase and code measurements only. Since the dispersive ionospheric delays affect phase and code measurements with opposite sign, it is possible to extract relative ionospheric range errors by forming the difference of code and phase measurements. Besides the (double) ionospheric range error, this difference contains the code and phase multipath noise, the instrumentation offsets, and the phase ambiguity. In order to suppress the dominant noise contribution, the code multipath noise, we use a Hatch-type filtering with a suitably chosen time constant. Note that there is a new phase ambiguity for each data arc, i.e., a continuous range of receiver-satellite measurements. Hence, we have to determine one new constant for each new data arc in order to calibrate the relative ionospheric range errors obtained from the filtered difference of phase and code observables. We have developed a model-assisted TEC calibration and reconstruction technique, using a simple polynomial model of the ionosphere, which approximates the ionosphere in the vicinity of the GNSS receiver by a single layer in a local, sun-fixed coordinate system. This technique is capable of calibrating the relative ionospheric range errors in near-realtime by using a Kalman-filter-type weighted-least-squares algorithm with a priori knowledge; the input measurement errors are determined from the Hatch-type filtering, while the initial model covariances may be determined, e.g., by the start-up weighted-least-squares solution. Without using any additional information the warm-up phase is found to be at least one hour. However, it is possible to shorten the warm-up phase by using, e.g., Klobuchar-model derived vertical TEC values as initial information. After the start-up phase, new model and ambiguity estimates are computed every couple of minutes by using both, the new measurements and the last model coefficients to update the model. Along with the model coefficients describing the variation of vertical TEC around the receiver we obtain further statistical information, e.g., the relative chi2 value of the fit which is a measure of how good the model Ansatz is consistent with the measured data, given the measurement errors and model covariances. By monitoring the chi2 value, deficiencies in data preprocessing (cycle slips) and, more importantly, extreme ionospheric perturbations can be detected. The comparison of vertical TEC derived from single-station single-frequency data obtained by the proposed method with TEC values obtained from European TEC maps under near-solar-minimum conditions shows a good agreement. This is encouraging, taking into account that we compare TEC valued determined from a single station using single-frequency GNSS data with TEC maps which are produced using dual-frequency phase and code GNSS data from a network of 20-30 GNSS receivers. Since the algorithm is able to calibrate ionospheric range errors containing different phase ambiguities for each arc, we have applied the algorithm to the reconstruction of vertical TEC from dual-frequency phase-only GNSS data. Here, the relative chi2 values are quite high, signaling that the simple single-layer polynomial ionospheric model cannot fully describe the ionospheric information contained in the low-(multipath-)noise GNSS phase observables Nevertheless, calibrated TEC can be obtained with this method. A possible continuation along the lines of this route would be to consider more elaborated ionospheric models, possibly transcending the single-layer approximation. We anticipate that the algorithm will work under other geophysical conditions, too, e.g., low-latitudes and/or high solar activity. The calibrated ionospheric range errors may be used in single-frequency point positioning. We compare the performance of our locally valid, near-real-time ionospheric corrections with the Klobuchar model, whose model coefficients are determined in intervals of days and are valid globally. The proposed algorithm is capable to derive calibrated ionospheric range errors from single-frequency GNSS data. In addition, a model describing the ionosphere in the vicinity of the receiver is provided, along with various statistical quantities. In the context of single-frequency point positioning, e.g. using low-cost GNSS receivers in quasi-static setups, this method is anticipated to provide autonomously determined, near-real-time ionospheric corrections comparable or better than the Klobuchar model. In (civil) aeronautical GBAS systems, which due to certification issues will continue to be restricted to use single-frequency GNSS equipment for some time, this method allows to detect ionospheric perturbations, including ionospheric gradient information, providing the necessary information for sigma monitors

AEROSOL PARTICLE DEPOSITION IN A T-SHAPED MICRO MIXER

ABSTRACT Micro technology supported aerosol processes provide a basis for integrated control of complex processes and therefore a promising research subject. A key aspect in aerosol technology is to control particle deposition, either to avoid clogging or to achieve a well defined coating of surfaces. As a first step we conducted an experimental and theoretical study of the particle deposition in a simple static T-shaped micro mixer. For the experiments monodisperse sodium chloride particles in the particle size range between 10 nm and 700 nm were used. The aerosol was introduced into one branch of the micro reactor and mixed with a particle-free air stream. The predominant particle deposition effect within the mixer is due to impaction, which is induced by the high curvature of stream lines at the inlet and in the mixing zone. Additional CFD calculations confirm the experimental results and show ways of optimizing the inlet geometry of the mixer, which should result in a significant reduction in impaction losses

Interactome Mapping of eIF3A in a Colon Cancer and an Immortalized Embryonic Cell Line Using Proximity-Dependent Biotin Identification

Translation initiation comprises complex interactions of eukaryotic initiation factor (eIF) subunits and the structural elements of the mRNAs. Translation initiation is a key process for building the cell’s proteome. It not only determines the total amount of protein synthesized but also controls the translation efficiency for individual transcripts, which is important for cancer or ageing. Thus, understanding protein interactions during translation initiation is one key that contributes to understanding how the eIF subunit composition influences translation or other pathways not yet attributed to eIFs. We applied the BioID technique to two rapidly dividing cell lines (the immortalized embryonic cell line HEK-293T and the colon carcinoma cell line HCT-166) in order to identify interacting proteins of eIF3A, a core subunit of the eukaryotic initiation factor 3 complex. We identified a total of 84 interacting proteins, with very few proteins being specific to one cell line. When protein biosynthesis was blocked by thapsigargin-induced endoplasmic reticulum (ER) stress, the interacting proteins were considerably smaller in number. In terms of gene ontology, although eIF3A interactors are mainly part of the translation machinery, protein folding and RNA binding were also found. Cells suffering from ER-stress show a few remaining interactors which are mainly ribosomal proteins or involved in RNA-binding

Study protocol: effects of treatment expectation toward repetitive transcranial magnetic stimulation (rTMS) in major depressive disorder—a randomized controlled clinical trial

Abstract Background Patients’ expectations toward any given treatment are highly important for the effectiveness of such treatment, as has been demonstrated for several disorders. In particular, in major depressive disorder (MDD), one of the most frequent and most serious mental disorders with severe consequences for the affected, the augmentation of available treatment options could mean a ground-breaking success. Repetitive transcranial magnetic stimulation (rTMS), a new, non-invasive, and well-tolerated intervention with proven effects in the treatment of MDD, appears particularly suitable in this context as it is assumed to exert its effect via structures implicated in networks relevant for both expectation and depression. Methods All patients will receive rTMS according to its approval. Half of the patients will be randomized to a psychological intervention, which is a comprehensive medical consultation aiming to improve positive treatment expectations; the control group will receive a conventional informed consent discussion (in the sense of a treatment-as-usual condition). As outcome parameters, instruments for both self-assessment and external assessment of depression symptoms will be applied. Furthermore, psycho-immunological parameters such as inflammation markers and the cortisol awakening response in saliva will be investigated. Resting-state functional magnetic resonance imaging (rs fMRI) will be performed to analyze functional connectivity, including the cerebellum, and to identify neuronal predictors of expectation effects. In addition, possible cerebellar involvement will be assessed based on a cerebellar-dependent motor learning paradigm (i.e., eyeblink conditioning). Discussion In this study, the effects of treatment expectations towards rTMS are investigated in patients with MDD. The aim of this study is to identify the mechanisms underlying the expectation effects and, beyond that, to expand the potential of non-invasive and well-tolerated treatments of MDD. Trial registration German Registry of Clinical Studies (DRKS DRKS00028017. Registered on 2022/03/07. URL: https://www.drks.de/drks_web/