Kalman-Filter Based Hybridization of Classic and Cold Atom Interferometry Accelerometers for Future Satellite Gravity Missions

Proof-of-principle demonstrations have been made for cold atom interferometer (CAI) sensors. Using CAI-based accelerometers in the next generation of satellite gravimetry missions can provide long-term stability and precise measurements of the non-gravitational forces acting on the satellites. This would allow a better understanding of climate change processes and geophysical phenomena which require long-term monitoring of mass variations with sufficient spatial and temporal resolution. The proposed accuracy and long-term stability of CAI-based accelerometers appear promising, while there are some major drawbacks in the long dead times and the comparatively small dynamic range of the sensors. One interesting way to handle these limitations is to use a hybridization with a conventional navigation sensor. This study discusses one possible solution to employ measurements of a CAI accelerometer together with a conventional Inertial Measurement Unit (IMU) using a Kalman filter framework. A hybrid navigation solution of these two sensors for applications on ground has already been demonstrated in simulations. Here, we adapt this method to a space-based GRACE-like gravimetry mission. A simulation is performed, where the sensitivity of the CAI accelerometer is estimated based on state-of-the-art ground sensors and further published space scenarios. Our results show that the Kalman filter framework can be used to combine the measurements of conventional inertial measurement units with the CAI accelerometers measurements in a way to benefit from the high accuracy of the conventional IMU measurements in higher frequencies together with the high stability of CAI measurements in lower frequencies. We will discuss the challenges, potential solutions, and the possible performance limits of the proposed hybrid accelerometry scenario

Metabolically engineered bacteria for producing hydrogen via fermentation

Hydrogen, the most abundant and lightest element in the universe, has much potential as a future energy source. Hydrogenases catalyse one of the simplest chemical reactions, 2H(+) + 2e(‐) ↔ H(2), yet their structure is very complex. Biologically, hydrogen can be produced via photosynthetic or fermentative routes. This review provides an overview of microbial production of hydrogen by fermentation (currently the more favourable route) and focuses on biochemical pathways, theoretical hydrogen yields and hydrogenase structure. In addition, several examples of metabolic engineering to enhance fermentative hydrogen production are presented along with some examples of expression of heterologous hydrogenases for enhanced hydrogen production

The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

Corruption and conscientiousness

Die nachfolgend berichteten Ergebnisse basieren auf einem vignettenbasierten 2x2-Szenario-Experiment, in das die Situationsfaktoren Entdeckungswahrscheinlichkeit und Vorteilswert sowie die Personenfaktoren Organisationaler Zynismus, das Fünf-Faktoren-Modell der Persönlichkeit und Intelligenz einbezogen wurden. In diesem Bericht werden vorrangig die Ergebnisse zur Persönlichkeitsdimension Gewissenhaftigkeit vorgestellt, einem der Faktoren des Fünf-Faktoren-Modells der Persönlichkeit. Diese Ergebnisse werden ausführlich berichtet, weil sie von besonderer Bedeutung für das vom TÜV Hannover/Sachsen-Anhalt e.V. finanzierte Forschungsprojekt Korruption – Risikofaktoren der Person und der Situation (Laufzeit 2011 bis 2015) sind. Die nachfolgend berichtete Untersuchung zeigt, dass ein akteurszentrierter Ansatz in der Korruptionsursachenforschung grundsätzlich sinnvoll ist. Es wurden 113 Auszubildende in den Bereichen Banken- und Versicherungen sowie Sozialversicherung befragt. Die Ergebnisse zeigen, dass Korruption als verbreitete Verhaltensweise angesehen wird, die jedoch als verwerflich gilt. Während die einbezogenen Situationsfaktoren keine nennenswerten Effekte auf die Korruptionsbereitschaft hatten, führten einige der Personenfaktoren zu signifikanten Ergebnissen. Gewissenhaftigkeit kommt hierbei als Schutzfaktor vor korrupten Handlungen besondere Bedeutung zu.The present study bases on a 2x2 scenario experiment, in which several situational and personal factors had been included. Situational factors were the probability of detection and benefit value; personal factors were organizational cynicism, the BIG 5-concept of personality and mental ability. Results presented in this work primarily relate to the personality dimension of conscientiousness. These results are of particular importance for the research project “Korruption – Risikofaktoren der Person und der Situation” ("Corruption - Risk factors of the person and the situation") (duration 2011 to 2015), funded by the TÜV Hannover/Sachsen-Anhalt. They show that an actor-centric approach is useful in research into the causes of corruption. 113 trainees working as banking and insurance specialists and social security clerks had been investigated in a survey study. Results show that corruption is considered as widespread practice, albeit it is thought to be objectionable. While the situational factors had no significant effects on the willingness to act corruptly, some personal factors led to significant results. Altogether, conscientiousness appears to be a protection factor against corrupt practices

Das HITec als Herzstück : Geodäsie und Quantenphysik verbinden sich

Das HITec ist für die Wissenschaft der Geodäsie und der Physik eine weltweit einzigartige Laborumgebung. Dort soll durch die Simulation verschiedenster Umweltbedingungen die Entwicklung von MultiSensorSystemen (MSS) der nächsten Generation praktisch realisiert werden. Forscherteams vom Institut für Erdmessung (IfE) und dem Geodätischen Institut Hannover (GIH) berichten

Advances in cold atom interferometer accelerometry and their impact on the sensitivity of gravity missions

Cold Atom Interferometer (CAI) accelerometry is proposed for future generations of satellite gravimetry missions. The technique can achieve high sensitivity and provide long-term stability and precise measurements of the non-gravitational accelerations acting on the satellites. This would reduce the overall instrumental errors and improve the observation of the Earth's gravity field and its change over time and enable a better understanding of several geophysical phenomena, also related to climate change. The current CAI accelerometers have shown great performance, especially in the lower frequencies. They have been able to considerably reduce the bias which is usually seen in the measurements of conventional electrostatic accelerometers. However, noise sources such as satellite rotation can degrade the CAI solution if they are not carefully compensated. In this study, we model the most impactful error sources which perturb the measurements of a CAI accelerometer onboard a GRACE-like satellite. We further investigate the sensitivity of the instrument to the various error sources, including detection noise, aberrations of laser wavefront, contrast loss due to the Coriolis acceleration and laser intensity inhomogeneity. We also consider the potential improvements which can be expected for satellite-based CAI accelerometers in the near and far future (e.g. longer interrogation time, rotation compensation in different scenarios, and increasing the laser waist). Additionally, we study their potential benefit for future satellite missions and the retrieval of the Earth's gravity field

COVID-19 and immunological regulations - from basic and translational aspects to clinical implications.

The COVID-19 pandemic caused by SARS-CoV-2 has far-reaching direct and indirect medical consequences. These include both the course and treatment of diseases. It is becoming increasingly clear that infections with SARS-CoV-2 can cause considerable immunological alterations, which particularly also affect pathogenetically and/or therapeutically relevant factors. Against this background we summarize here the current state of knowledge on the interaction of SARS-CoV-2/COVID-19 with mediators of the acute phase of inflammation (TNF, IL-1, IL-6), type 1 and type 17 immune responses (IL-12, IL-23, IL-17, IL-36), type 2 immune reactions (IL-4, IL-13, IL-5, IL-31, IgE), B-cell immunity, checkpoint regulators (PD-1, PD-L1, CTLA4), and orally druggable signaling pathways (JAK, PDE4, calcineurin). In addition, we discuss in this context non-specific immune modulation by glucocorticosteroids, methotrexate, antimalarial drugs, azathioprine, dapsone, mycophenolate mofetil and fumaric acid esters, as well as neutrophil granulocyte-mediated innate immune mechanisms. From these recent findings we derive possible implications for the therapeutic modulation of said immunological mechanisms in connection with SARS-CoV-2/COVID-19. Although, of course, the greatest care should be taken with patients with immunologically mediated diseases or immunomodulating therapies, it appears that many treatments can also be carried out during the COVID-19 pandemic; some even appear to alleviate COVID-19

Advances in Atom Interferometry and their Impacts on the Performance of Quantum Accelerometers On-board Future Satellite Gravity Missions

International audienceRecent advances in cold atom interferometry have cleared the path for space applications of quantum inertial sensors, whose level of stability is expected to increase dramatically with the longer interrogation times accessible in space. In this study, a comprehensive in-orbit model is developed for a Mach-Zehnder-type cold-atom accelerometer. Performance tests are realized under different assumptions, and the impact of various sources of errors on instrument stability is evaluated. Current and future advances for space-based atom interferometry are discussed, and their impact on the performance of quantum sensors on-board satellite gravity missions is investigated in three different scenarios: state-of-the-art scenario, near-future (between the next 5 and 10 years) and far-future scenarios (between the next 10 to 20 years). We show that one can achieve a sensitivity level close to 5E-10 with the current state-of-the-art technology. We also estimate that in the near and far-future, atom interferometry in space is expected to achieve sensitivity levels of 1E-11 and 1E-12, respectively. A roadmap for improvements in atom interferometry is provided that would maximize the performance of future CAI accelerometers, considering their technical capabilities. Finally, the possibility and challenges of having ultra-sensitive atom interferometry in space for future space missions are discussed

Improved Modeling for Hybrid Accelerometers Onboard Future Satellite Gravity Missions

Cold Atom Interferometry (CAI) has proven to be a very efficient technique to achieve high sensitivity for absolute inertial sensing. It is proposed to use CAI accelerometers onboard future generations of satellite gravimetry missions to provide long-term stability and precise measurements of the non-gravitational forces acting on the satellites. This would reduce the overall instrumental errors and improve our knowledge of the Earth gravity field and its change over time. This would allow a better understanding of climate change processes and various geophysical phenomena (e.g. post-glacial rebound). Even though the accuracy and long-term stability of CAI-based accelerometers seem promising, they suffer from long dead times and a comparatively small dynamic range of the sensor. One promising way to handle those drawbacks is to use them in hybrid combination together with a conventional electrostatic accelerometer. We have previously discussed a specific possible solution to employ the measurements of a CAI accelerometer together with a classical accelerometer by applying a Kalman filter Framework which had already shown an improved navigation solution with respect to a reference trajectory. Here, we implement an improved CAI modeling in the simulation to consider the in-flight conditions of a GRACE-like gravimetry mission (e. g. the impact of satellite rotation and gravity gradients) on the CAI measurements. The noise model is also improved to generate more realistic simulated measurements, by considering the impact of different noise sources (e.g. shot noise, detection noise, laser frequency noise and the vibration of the reference mirror). We then perform a closed-loop simulation in which we employ measurements of a CAI accelerometer together with a conventional Inertial Measurement Unit (IMU) using the improved Kalman filter framework and we compare the combined accuracy in the determination of the non-gravitational forces. In addition, we perform simulations using two or three CAI axes. We also study the possibility of having a CAI with a very long interrogation time (>10 seconds) and discuss the challenges and potential improvements. Finally, we compare the recovered gravity field for the various test cases with GRACE solutions