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

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

Bose–Einstein condensation in large time-averaged optical ring potentials

Interferometric measurements with matter waves are established techniques for sensitive gravimetry, rotation sensing, and measurement of surface interactions, but compact interferometers will require techniques based on trapped geometries. In a step towards the realisation of matter wave interferometers in toroidal geometries, we produce a large, smooth ring trap for Bose–Einstein condensates using rapidly scanned time-averaged dipole potentials. The trap potential is smoothed by using the atom distribution as input to an optical intensity correction algorithm. Smooth rings with a diameter up to 300 μm are demonstrated. We experimentally observe and simulate the dispersion of condensed atoms in the resulting potential, with good agreement serving as an indication of trap smoothness. Under time of flight expansion we observe low energy excitations in the ring, which serves to constrain the lower frequency limit of the scanned potential technique. The resulting ring potential will have applications as a waveguide for atom interferometry and studies of superfluidity

Lhx2 Is Required for Patterning and Expansion of a Distinct Progenitor Cell Population Committed to Eye Development

Progenitor cells committed to eye development become specified in the prospective forebrain and develop subsequently into the optic vesicle and the optic cup. The optic vesicle induces formation of the lens placode in surface ectoderm from which the lens develops. Numerous transcription factors are involved in this process, including the eye-field transcription factors. However, many of these transcription factors also regulate the patterning of the anterior neural plate and their specific role in eye development is difficult to discern since eye-committed progenitor cells are poorly defined. By using a specific part of the Lhx2 promoter to regulate Cre recombinase expression in transgenic mice we have been able to define a distinct progenitor cell population in the forebrain solely committed to eye development. Conditional inactivation of Lhx2 in these progenitor cells causes an arrest in eye development at the stage when the optic vesicle induces lens placode formation in the surface ectoderm. The eye-committed progenitor cell population is present in the Lhx2−/− embryonic forebrain suggesting that commitment to eye development is Lhx2-independent. However, re-expression of Lhx2 in Lhx2−/− progenitor cells only promotes development of retinal pigment epithelium cells, indicating that Lhx2 promotes the acquisition of the oligopotent fate of these progenitor cells. This approach also allowed us to identify genes that distinguish Lhx2 function in eye development from that in the forebrain. Thus, we have defined a distinct progenitor cell population in the forebrain committed to eye development and identified genes linked to Lhx2's function in the expansion and patterning of these progenitor cells

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a

ARIA digital anamorphosis : Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed.Peer reviewe

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

ARIA digital anamorphosis: Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed