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See detailSORA Methodology for Multi-UAS Airframe Inspections in an Airport
Martinez Luna, Carol UL; Sanchez Cuevas, Pedro Jesus UL; Gerasimou, Simos et al

in Drones (2021), 5(4 141),

Deploying Unmanned Aircraft Systems (UAS) in safety- and business-critical operations requires demonstrating compliance with applicable regulations and a comprehensive understanding of the residual risk ... [more ▼]

Deploying Unmanned Aircraft Systems (UAS) in safety- and business-critical operations requires demonstrating compliance with applicable regulations and a comprehensive understanding of the residual risk associated with the UAS operation. To support these activities and enable the safe deployment of UAS into civil airspace, the European Union Aviation Safety Agency (EASA) has established a UAS regulatory framework that mandates the execution of safety risk assessment for UAS operations in order to gain authorization to carry out certain types of operations. Driven by this framework, the Joint Authorities for Rulemaking on Unmanned Systems (JARUS) released the Specific Operation Risk Assessment (SORA) methodology that guides the systematic risk assessment for UAS operations. However, existing work on SORA and its applications focuses mainly on single UAS operations, offering limited support for assuring operations conducted with multiple UAS and with autonomous features. Therefore, the work presented in this paper analyzes the application of SORA for a Multi-UAS airframe inspection (AFI) operation, that involves deploying multiple UAS with autonomous features inside an airport. We present the decision-making process of each SORA step and its application to a multiple UAS scenario. The results shows that the procedures and safety features included in the Multi-AFI operation such as workspace segmentation, the independent multi-UAS AFI crew proposed, and the mitigation actions provide confidence that the operation can be conducted safely and can receive a positive evaluation from the competent authorities. We also present our key findings from the application of SORA and discuss how it can be extended to better support multi-UAS operations. [less ▲]

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See detailProximal Policy Optimisation for a Private Equity Recommitment System
Kieffer, Emmanuel UL; Pinel, Frederic UL; Meyer, Thomas et al

in Springer CCIS series (2021)

Recommitments are essential for limited partner investors to maintain a target exposure to private equity. However, recommitting to new funds is irrevocable and expose investors to cashflow uncertainty ... [more ▼]

Recommitments are essential for limited partner investors to maintain a target exposure to private equity. However, recommitting to new funds is irrevocable and expose investors to cashflow uncertainty and illiquidity. Maintaining a specific target allocation is therefore a tedious and critical task. Unfortunately, recommitment strategies are still manually designed and few works in the literature have endeavored to develop a recommitment system balancing opportunity cost and risk of default. Due to its strong similarities to a control system, we propose to “learn how to recommit” with Reinforcement Learning (RL) and, more specifically, using Proximal Policy Optimisation (PPO). To the best of our knowledge, this is the first attempt a RL algorithm is applied to private equity with the aim to solve the recommitment problematic. After training the RL model on simulated portfolios, the resulting recommitment policy is compared to state-of-the-art strategies. Numerical results suggest that the trained policy can achieve high target allocation while bounding the risk of being overinvested. [less ▲]

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See detailThe TRPV2 channel mediates Ca2+ influx and the Delta 9-THC-dependent decrease in osmotic fragility in red blood cells
Belkacemi, Anouar; Fecher-Trost, Claudia; Tinschert, Rene et al

in HAEMATOLOGICA (2021), 106(8), 2246-2250

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See detailA deep learning-based concept for high throughput image flow cytometry
Martin-Wortham, Julie; Recktenwald, Steffen M.; Lopes, Marcelle G. M. et al

in APPLIED PHYSICS LETTERS (2021), 118(12),

We propose a flow cytometry concept that combines a spatial optical modulation scheme and deep learning for lensless cell imaging. Inspired by auto-encoder techniques, an artificial neural network mimics ... [more ▼]

We propose a flow cytometry concept that combines a spatial optical modulation scheme and deep learning for lensless cell imaging. Inspired by auto-encoder techniques, an artificial neural network mimics the optical transfer function of a particular microscope and camera for certain types of cells once trained and reconstructs microscope images from simple waveforms that are generated by cells in microfluidic flow. This eventually enables the label-free detection of cells at high throughput while simultaneously providing their corresponding brightfield images. The present work focuses on the computational proof of concept of this method by mimicking the waveforms. Our suggested approach would require a minimum set of optical components such as a collimated light source, a slit mask, and a light sensor and could be easily integrated into a ruggedized lab-on-chip device. The method is benchmarked with a well-investigated dataset of red blood cell images. [less ▲]

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See detailAcanthocyte Sedimentation Rate as a Diagnostic Biomarker for Neuroacanthocytosis Syndromes: Experimental Evidence and Physical Justification.
Darras, Alexis; Peikert, Kevin; Rabe, Antonia et al

in Cells (2021), 10(4),

(1) Background: Chorea-acanthocytosis and McLeod syndrome are the core diseases among the group of rare neurodegenerative disorders called neuroacanthocytosis syndromes (NASs). NAS patients have a ... [more ▼]

(1) Background: Chorea-acanthocytosis and McLeod syndrome are the core diseases among the group of rare neurodegenerative disorders called neuroacanthocytosis syndromes (NASs). NAS patients have a variable number of irregularly spiky erythrocytes, so-called acanthocytes. Their detection is a crucial but error-prone parameter in the diagnosis of NASs, often leading to misdiagnoses. (2) Methods: We measured the standard Westergren erythrocyte sedimentation rate (ESR) of various blood samples from NAS patients and healthy controls. Furthermore, we manipulated the ESR by swapping the erythrocytes and plasma of different individuals, as well as replacing plasma with dextran. These measurements were complemented by clinical laboratory data and single-cell adhesion force measurements. Additionally, we followed theoretical modeling approaches. (3) Results: We show that the acanthocyte sedimentation rate (ASR) with a two-hour read-out is significantly prolonged in chorea-acanthocytosis and McLeod syndrome without overlap compared to the ESR of the controls. Mechanistically, through modern colloidal physics, we show that acanthocyte aggregation and plasma fibrinogen levels slow down the sedimentation. Moreover, the inverse of ASR correlates with the number of acanthocytes (R2=0.61, p=0.004). (4) Conclusions: The ASR/ESR is a clear, robust and easily obtainable diagnostic marker. Independently of NASs, we also regard this study as a hallmark of the physical view of erythrocyte sedimentation by describing anticoagulated blood in stasis as a percolating gel, allowing the application of colloidal physics theory. [less ▲]

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See detailLingering Dynamics in Microvascular Blood Flow.
Kihm, Alexander; Quint, Stephan; Laschke, Matthias W. et al

in Biophysical journal (2021), 120(3), 432-439

The microvascular networks in the body of vertebrates consist of the smallest vessels such as arterioles, capillaries, and venules. The flow of red blood cells (RBCs) through these networks ensures the ... [more ▼]

The microvascular networks in the body of vertebrates consist of the smallest vessels such as arterioles, capillaries, and venules. The flow of red blood cells (RBCs) through these networks ensures the gas exchange in as well as the transport of nutrients to the tissues. Any alterations in this blood flow may have severe implications on the health state. Because the vessels in these networks obey dimensions similar to the diameter of RBCs, dynamic effects on the cellular scale play a key role. The steady progression in the numerical modeling of RBCs, even in complex networks, has led to novel findings in the field of hemodynamics, especially concerning the impact and the dynamics of lingering events when a cell meets a branch of the network. However, these results are yet to be matched by a detailed analysis of the lingering experiments in vivo. To quantify this lingering effect in in vivo experiments, this study analyzes branching vessels in the microvasculature of Syrian golden hamsters via intravital microscopy and the use of an implanted dorsal skinfold chamber. It also presents a detailed analysis of these lingering effects of cells at the apex of bifurcating vessels, affecting the temporal distribution of plasmatic zones of blood flow in the branches and even causing a partial blockage in severe cases. [less ▲]

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See detailThe Erythrocyte Sedimentation Rate and Its Relation to Cell Shape and Rigidity of Red Blood Cells from Chorea-Acanthocytosis Patients in an Off-Label Treatment with Dasatinib.
Rabe, Antonia; Kihm, Alexander; Darras, Alexis et al

in Biomolecules (2021), 11(5),

BACKGROUND: Chorea-acanthocytosis (ChAc) is a rare hereditary neurodegenerative disease with deformed red blood cells (RBCs), so-called acanthocytes, as a typical marker of the disease. Erythrocyte ... [more ▼]

BACKGROUND: Chorea-acanthocytosis (ChAc) is a rare hereditary neurodegenerative disease with deformed red blood cells (RBCs), so-called acanthocytes, as a typical marker of the disease. Erythrocyte sedimentation rate (ESR) was recently proposed as a diagnostic biomarker. To date, there is no treatment option for affected patients, but promising therapy candidates, such as dasatinib, a Lyn-kinase inhibitor, have been identified. METHODS: RBCs of two ChAc patients during and after dasatinib treatment were characterized by the ESR, clinical hematology parameters and the 3D shape classification in stasis based on an artificial neural network. Furthermore, mathematical modeling was performed to understand the contribution of cell morphology and cell rigidity to the ESR. Microfluidic measurements were used to compare the RBC rigidity between ChAc patients and healthy controls. RESULTS: The mechano-morphological characterization of RBCs from two ChAc patients in an off-label treatment with dasatinib revealed differences in the ESR and the acanthocyte count during and after the treatment period, which could not directly be related to each other. Clinical hematology parameters were in the normal range. Mathematical modeling indicated that RBC rigidity is more important for delayed ESR than cell shape. Microfluidic experiments confirmed a higher rigidity in the normocytes of ChAc patients compared to healthy controls. CONCLUSIONS: The results increase our understanding of the role of acanthocytes and their associated properties in the ESR, but the data are too sparse to answer the question of whether the ESR is a suitable biomarker for treatment success, whereas a correlation between hematological and neuronal phenotype is still subject to verification. [less ▲]

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See detailEvaluation of global ocean tide models based on tidal gravity observations in China
Tan, Hongbo; Francis, Olivier UL; Wu, Guiju et al

in Geodesy and Geodynamics (2021), 12(6), 451-458

Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia. In this paper, taking ... [more ▼]

Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia. In this paper, taking advantage of a unique network of gravity tidal stations all over the Chinese mainland, we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models. The results show that the average efficiencies of the ocean tidal loading correction for O1, K1, M2 are 77%, 73% and 59%, respectively. The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations, but relative worse at stations far from ocean. [less ▲]

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See detailDivision in modules and Kummer theory
Tronto, Sebastiano UL

E-print/Working paper (2021)

In this work we generalize the concept of injective module and develop a theory of divisibility for modules over a general ring, which provides a general and unified framework to study Kummer-like field ... [more ▼]

In this work we generalize the concept of injective module and develop a theory of divisibility for modules over a general ring, which provides a general and unified framework to study Kummer-like field extensions arising from commutative algebraic groups. With these tools we provide an effective bound for the degree of the field extensions arising from division points of elliptic curves, extending previous results of Javan Peykar for CM curves and of Lombardo and the author for the non-CM case. [less ▲]

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See detailSome uniform bounds for elliptic curves over Q
Lombardo, Davide; Tronto, Sebastiano UL

E-print/Working paper (2021)

We give explicit uniform bounds for several quantities relevant to the study of Galois representations attached to elliptic curves E/Q. We consider in particular the subgroup of scalars in the image of ... [more ▼]

We give explicit uniform bounds for several quantities relevant to the study of Galois representations attached to elliptic curves E/Q. We consider in particular the subgroup of scalars in the image of Galois, the first Galois cohomology group with values in the torsion of E, and the Kummer extensions generated by points of infinite order in E(Q). [less ▲]

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See detailNew Weak Admissibility Semantics for Abstract Argumentation
Dauphin, Jérémie UL; Rienstra, Tjitze; van der Torre, Leon UL

in International Conference on Logic and Argumentation (2021)

Baumann, Brewka and Ulbricht recently introduced weak admissibility as an alternative to Dung’s notion of admissibility, and they used it to define weakly preferred, weakly complete and weakly grounded ... [more ▼]

Baumann, Brewka and Ulbricht recently introduced weak admissibility as an alternative to Dung’s notion of admissibility, and they used it to define weakly preferred, weakly complete and weakly grounded semantics of argumentation frameworks. In earlier work, we introduced two variants of their new semantics which we called qualified and semi-qualified semantics. We analysed all known variants of weak admissibility semantics with respect to some of the principles discussed in the literature on abstract argumentation, as well as some new principles we introduced to distinguish them all. Such a principle-based analysis can be used not only for selecting a semantics for an application, or for algorithmic design, but also for further research into weak admissibility semantics. In this paper, we introduce six new kinds of semantics based on weak admissibility, and we provide an initial principle-based analysis. The analysis illustrates various ways in which the new semantics improve on existing ones. [less ▲]

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See detailConstitutional engineering of State of exception regimes within the European Union
Gerkrath, Jörg UL

E-print/Working paper (2021)

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See detailAnonymization between minimization and erasure: The perspectives of French and Italian data protection authorities
Podda, Emanuela UL; Vigna, Francesco UL

in Electronic Government and the Information Systems Perspective: 10th International Conference, EGOVIS 2021 Virtual Event, September 27–30, 2021 Proceedings (2021)

Two years after the General Data Protection Regulation (GDPR) went into effect, data anonymization remains one of the main issues linked to fragmen-tation in the Member States’ anonymization policies, in ... [more ▼]

Two years after the General Data Protection Regulation (GDPR) went into effect, data anonymization remains one of the main issues linked to fragmen-tation in the Member States’ anonymization policies, in which regard stakehold-ers would like additional guidelines. In keeping with this premise, this article aims to analyze and compare trends in the implementation and enforcement of anonymization policies put in place by data protection authorities in two countries: France and Italy. This analysis makes it possible to trace the evolution of these policies and high-light their critical importance in applying the data minimization principle and in enforcing the right to erasure under Art. 17 GDPR. [less ▲]

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See detailDemand-Based Adaptive Multi-Beam Pattern and Footprint Planning for High Throughput GEO Satellite Systems
Jubba Honnaiah, Puneeth UL; Maturo, Nicola; Chatzinotas, Symeon UL et al

in IEEE Open Journal of the Communications Society (2021)

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See detailScalable Cell-Free Massive MIMO Systems: Impact of Hardware Impairments
Papazafeiropoulos, Anastasios; Björnson, Emil; Kourtessis, Pandelis et al

in IEEE Transactions on Vehicular Technology (2021), 70(10), 9701-9715

Scalable cell-free CF (SCF) massive multiple-input-multiple-output (mMIMO) systems is a promising technology to cover the demands for higher data rates and increasing number of users in fifth generation ... [more ▼]

Scalable cell-free CF (SCF) massive multiple-input-multiple-output (mMIMO) systems is a promising technology to cover the demands for higher data rates and increasing number of users in fifth generation (5G) networks and beyond. According to this concept, a large number of distributed access points (APs) communicates with the users in the network by means of joint coherent transmission while facing the main challenges against standard CF mMIMO systems being their high fronthaul load and computational complexity. Given that the cost-efficient deployment of such large networks requires low-cost transceivers being prone to unavoidable hardware imperfections, in this work, we focus on their impact on the advantageous SCF mMIMO systems by means of a general model accounting for both additive and multiplicative hardware impairments (HWIs). Notably, the scalability, depending on the time-variant characteristics of the network, is clearly affected by means of HWIs being time-varying. There is no other work in the literature studying the phase noise (PN) in CF mMIMO systems or in general any HWIs in SCF mMIMO systems. Hence, we derive upper and lower bounds on the uplink capacity accounting for HWIs. Especially, the lower bound is derived in closed-form by means of the theory of deterministic equivalents (DEs) and after obtaining the optimal hardware-aware (HA) partial minimum mean-squared error (PMMSE) combiner. Among the interesting findings, we observe that separate local oscillators (SLOs) outperform a common LO (CLO) architecture, and the additive transmit distortion degrades more the performance than the receive distortion. [less ▲]

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See detailVortical flow structures induced by red blood cells in capillaries.
Yaya, François; Römer, Johannes; Guckenberger, Achim et al

in Microcirculation (New York, N.Y. : 1994) (2021), 28(5), 12693

OBJECTIVE: Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles ... [more ▼]

OBJECTIVE: Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles and molecules in the flowing plasma. We conducted an experimental study on the flow field around red blood cells in capillary flow that is complemented by simulations of vortical flow between red blood cells. METHODS: Red blood cells were injected in a 10 × 12 µm rectangular microchannel at a low hematocrit, and the flow field around one or two cells was captured by a high-speed camera that tracked 250 nm nanoparticles in the flow field, acting as tracers. RESULTS: While the flow field around a steady "croissant" shape is found to be similar to that of a rigid sphere, the flow field around a "slipper" shape exhibits a small vortex at the rear of the red blood cell. Even more pronounced are vortex-like structures observed in the central region between two neighboring croissants. CONCLUSIONS: The rotation frequency of the vortices is to a good approximation, inversely proportional to the distance between the cells. Our experimental data are complemented by numerical simulations. [less ▲]

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See detailHeartbeat evoked potentials in patients with posttraumatic stress disorder: an unaltered neurobiological regulation system?
Schmitz, Marius; Müller, Laura E.; Seitz, Katja I. et al

in European Journal of Psychotraumatology (2021), 12(1), 1987686

Background: Early life maltreatment is a risk factor for psychiatric disorders, including posttraumatic stress disorder (PTSD). Posttraumatic stress disorder is a severe and heterogeneous disorder with ... [more ▼]

Background: Early life maltreatment is a risk factor for psychiatric disorders, including posttraumatic stress disorder (PTSD). Posttraumatic stress disorder is a severe and heterogeneous disorder with fluctuating states of emotional over- and undermodulation including hypervigilance, dissociation, and emotion regulation deficits. The perception and regulation of emotions have been linked to interoception, the cortical representation and sensing of inner bodily processes. Although first therapeutic approaches targeting bodily sensations have been found effective in patients with PTSD, and deficits in interoceptive signal representation have been reported in other trauma-related disorders such as borderline personality disorder (BPD), the role of interoception remains largely unexplored for PTSD. Objective: The objective was to investigate the cortical representation of cardiac interoceptive signals in patients with PTSD and its associations with early life maltreatment, trait dissociation, and emotion dysregulation. Methods: Twenty-four medication-free patients with PTSD and 31 healthy controls (HC) completed a 5-min resting electrocardiogram (ECG) with parallel electroencephalogram (EEG). Heartbeat evoked potential (HEP) amplitudes as a measure for cortical representation of cardiac interoceptive signals were compared between groups and correlated with self-report questionnaires. Results: We did not find significantly different mean HEP amplitudes in patients with PTSD compared to HC, although HEPs of patients with PTSD were descriptively higher. No significant associations between mean HEP amplitudes and early life maltreatment, trait dissociation or emotion dysregulation were obtained within the groups. Conclusion: The current finding does not indicate deficits in interoceptive signal representation at rest in individuals with PTSD. Whether patients with PTSD show altered HEP modulations during emotion regulation tasks and might benefit from therapeutic approaches aiming at changing the perception of bodily signals, needs to be investigated in future studies. [less ▲]

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See detailOptimal Randomized Partial Checking for Decryption Mix Nets
Haines, Thomas; Mueller, Johannes UL

in Information Security and Privacy - 26th Australasian Conference, ACISP 2021, Virtual Event, December 1-3, 2021, Proceedings (2021)

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See detailWhere were the repair ingredients for Defects4j bugs?
Yang, Deheng; Liu, Kui; Kim, Dongsun et al

in Empirical Software Engineering (2021), 26(6), 1--33

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See detailUsing Blockchain to Coordinate Federal Processes: The Case of Germany's Federal Office for Migration and Refugees
Amend, Julia; van Dun, Christopher; Fridgen, Gilbert UL et al

in Urbach, Nils; Röglinger, Maximilian; Kautz, Karlheinz (Eds.) et al Digitalization Cases Vol. 2: Mastering Digital Transformation for Global Business (2021)

(a)Situation faced: The German asylum procedure requires close cooperation and information exchange between various authorities at the municipal, state, and federal levels. Federal separation of ... [more ▼]

(a)Situation faced: The German asylum procedure requires close cooperation and information exchange between various authorities at the municipal, state, and federal levels. Federal separation of competencies inhibits the delegation of process governance to a central authority such as the Federal Office for Migration and Refugees (BAMF). This separation also leads to regional differences as federal laws govern the procedure's general steps, whereas state laws govern implementation. Moreover, existing solutions for cross-organizational collaboration are limited in terms of flexibility, security, and data quality. As a result, the exchange of certain data on asylum procedures still occurs using Excel spreadsheets and e-mails.(b)Action taken: Against this backdrop, the BAMF explored technological options that would support the decentralized governance of the asylum procedure. After a preliminary evaluation, the BAMF decided to explore a solution based on blockchain technology. Building upon a successful proof of concept, the BAMF initiated a pilot project with Saxony's central immigration authority. This project aims to develop a blockchain solution that supports the coordination of asylum procedures and can be easily adapted to local differences and functional requirements.(c)Results achieved: The use of the blockchain solution allows for efficient, secure, and timely distribution of status information. It supports communication and improves coordination between authorities. Despite an apparent conflict between blockchain principles and data privacy requirements, the BAMF's design complies with relevant regulation (notably the GDPR). As a first-of-its-kind project, it outlines best practices and provides valuable insights into opportunities and challenges arising from the use of blockchain in the public sector.(d)Lessons learned: The BAMF's case demonstrates that blockchain solutions can be promising alternatives when the delegation of process governance to a central party is not desirable and when federal principles of organization are to be reflected technologically. However, blockchain projects require special attention to managing know-how and capabilities, software development activities, stakeholders, the regulatory context, and cross-organizational governance. [less ▲]

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