Samantha’s Dilemma: A Look into a Life with AI

In this paper, I propose a thought experiment, “Samantha’s Dilemma,” which captures the complexity of determining whether moral considerations can be attributed to artificial intelligence (AI). Deciding whether or not we attribute autonomous freedom to artificial beings lays the foundation, not only for our relationships with AI, but with any ‘intelligent’ species we encounter in the future. By analyzing several core arguments regarding the treatment of artificial beings, I will show that abandoning our predominant self-serving tendencies and choosing not to limit the potentiality of autonomous AI is not only the safest course of action, but also the morally correct one

Stuck Bit Error Identification for the TerraSAR-X and TanDEM-X Onboard Memory

Errors in memory storage devices in the form of erroneous bits induced by radiation are a common issue for every space- craft in orbit. Therefore, well established techniques detect and directly correct these errors in the storage hardware. Sporadically single memory cells can temporarily get “stuck” at a false bit in which case they cannot be corrected. Those stuck bits can persist up to several months generating the same errors during every memory scrubbing cycle. In order to assess the current memory status a method to distinguish between regular and stuck-bit errors is needed. This paper therefore presents a classification approach based on the DBSCAN method where stuck bits are identified as outliers and clustered accordingly. The approach first is verified with simulated data that resembles the error structure of memory errors on TerraSAR-X and TanDEM-X. Subsequently, the method is validated with the memory errors recorded by both satellites throughout their lifetime

A Decade of TerraSAR-X and TanDEM-X Operation: A Retrospective on the Performance of the SAR System and an Outlook to the Future

TerraSAR-X and its almost identical twin satellite TanDEM-X have provided high resolution radar images for years and Digital Elevation Models with unprecedented accuracy. The SAR image quality and accuracy has remained constant since launch and is owed to a very stable instrument. A thorough system health monitoring is utilized in order to maintain this stability. On the one hand a short-term verification of the individual acquisitions constantly exploits satellite telemetry from the SAR instrument and the on-board calibration system. Hence performance hanges, e.g. in terms of hardware degradation, can quickly be identified and corrected. For example by monitoring the antenna’s T/R modules via pseudo noise gating, dysfunctional modules could be detected in order to re-adjust the system accordingly. On the other hand a long-term system monitoring approach furthermore was designed to detect long-term system parameter trends and degradations that may affect data quality or imaging capabilities. In particular on-ground measurements are evaluated by continuously imaging globally distributed reference targets such as corner reflectors or test sights with a well-known topography. It was initiated with the launch of TerraSAR-X thus provides a variety of long-term parameter time series. Stimulated by this approach a study has been conducted to analyze the impact of solar events like radiation or the annual eclipse due to the satellites’ orbit geometry. Although the effects are taken into account by calibration the results provide valuable information to interpret monitoring results and gain a deeper understanding of the system. Besides retrospecting the SAR system the goal of this paper is also to give a summary of the TerraSAR-X and TanDEM-X mission with focus on the calibration and the systems’ functionality. The mission status will concentrate mainly on the performance of the global Digital Elevation Model which was completed in September 2016. Having used precise calibration methods and improved processing algorithms, the dataset shows an outstanding quality. In the end up to 20.000 tiles with a size of 1° x 1° were generated yielding an overall absolute height accuracy of 3.5 meters and covering more than 99% of the globe. As the satellites are still in good condition and consumables are sufficient, the mission was extended to generate a change layer as an update of the global DEM. By adjusting acquisition strategies and processing methods, fewer acquisitions are sufficient to achieve the same accuracy as for the global DEM. Furthermore, a brief outline of the proposed future L-band satellite formation is drawn. The ambitious mission shall provide data to help solving pressing climate-related questions. As an example the proposed system will be able to penetrate forest canopy in order to estimate biomass on a global scale. Equipped with a reflector antenna and exploiting the innovative digital beamforming technique, Tandem-L will be capable of illuminating a 350 km wide swath on ground acquiring up to 8 terabyte of data per day. This enables a weekly global coverage, which is a precondition for observing dynamic processes in the bio-, geo-, hydro- and cryosphere

Probing single electrons across 300 mm spin qubit wafers

Building a fault-tolerant quantum computer will require vast numbers of physical qubits. For qubit technologies based on solid state electronic devices, integrating millions of qubits in a single processor will require device fabrication to reach a scale comparable to that of the modern CMOS industry. Equally importantly, the scale of cryogenic device testing must keep pace to enable efficient device screening and to improve statistical metrics like qubit yield and process variation. Spin qubits have shown impressive control fidelities but have historically been challenged by yield and process variation. In this work, we present a testing process using a cryogenic 300 mm wafer prober to collect high-volume data on the performance of industry-manufactured spin qubit devices at 1.6 K. This testing method provides fast feedback to enable optimization of the CMOS-compatible fabrication process, leading to high yield and low process variation. Using this system, we automate measurements of the operating point of spin qubits and probe the transitions of single electrons across full wafers. We analyze the random variation in single-electron operating voltages and find that this fabrication process leads to low levels of disorder at the 300 mm scale. Together these results demonstrate the advances that can be achieved through the application of CMOS industry techniques to the fabrication and measurement of spin qubits.Comment: 15 pages, 4 figures, 7 extended data figure

Human small intestinal infection by SARS-CoV-2 is characterized by a mucosal infiltration with activated CD8+ T cells

The SARS-CoV-2 pandemic has so far claimed over three and a half million lives worldwide. Though the SARS-CoV-2 mediated disease COVID-19 has first been characterized by an infection of the upper airways and the lung, recent evidence suggests a complex disease including gastrointestinal symptoms. Even if a direct viral tropism of intestinal cells has recently been demonstrated, it remains unclear, whether gastrointestinal symptoms are caused by direct infection of the gastrointestinal tract by SARS-CoV-2 or whether they are a consequence of a systemic immune activation and subsequent modulation of the mucosal immune system. To better understand the cause of intestinal symptoms we analyzed biopsies of the small intestine from SARS-CoV-2 infected individuals. Applying qRT-PCR and immunohistochemistry, we detected SARS-CoV-2 RNA and nucleocapsid protein in duodenal mucosa. In addition, applying imaging mass cytometry and immunohistochemistry, we identified histomorphological changes of the epithelium, which were characterized by an accumulation of activated intraepithelial CD8(+) T cells as well as epithelial apoptosis and subsequent regenerative proliferation in the small intestine of COVID-19 patients. In summary, our findings indicate that intraepithelial CD8(+) T cells are activated upon infection of intestinal epithelial cells with SARS-CoV-2, providing one possible explanation for gastrointestinal symptoms associated with COVID-19

MAGUKs, scaffolding proteins at cell junctions, are substrates of different proteases during apoptosis

A major feature of apoptotic cell death is gross structural changes, one of which is the loss of cell–cell contacts. The caspases, executioners of apoptosis, were shown to cleave several proteins involved in the formation of cell junctions. The membrane-associated guanylate kinases (MAGUKs), which are typically associated with cell junctions, have a major role in the organization of protein–protein complexes at plasma membranes and are therefore potentially important caspase targets during apoptosis. We report here that MAGUKs are cleaved and/or degraded by executioner caspases, granzyme B and several cysteine cathepsins in vitro. When apoptosis was induced by UV-irradiation and staurosporine in different epithelial cell lines, caspases were found to efficiently cleave MAGUKs in these cell models, as the cleavages could be prevented by a pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(OMe)fluoromethylketone. Using a selective lysosomal disrupting agent -leucyl--leucine methyl ester, which induces apoptosis through the lysosomal pathway, it was further shown that MAGUKs are also cleaved by the cathepsins in HaCaT and CaCo-2 cells. Immunohistological data showed rapid loss of MAGUKs at the sites of cell–cell contacts, preceding actual cell detachment, suggesting that cleavage of MAGUKs is an important step in fast and efficient cell detachment

Higher Order Sobolev-Type Spaces on the Real Line

This paper gives a characterization of Sobolev functions on the real line by means of pointwise inequalities involving finite differences. This is also shown to apply to more general Orlicz-Sobolev, Lorentz-Sobolev, and Lorentz-Karamata-Sobolev spaces

Higher Order Sobolev-Type Spaces on the Real Line

This paper gives a characterization of Sobolev functions on the real line by means of pointwise inequalities involving finite differences. This is also shown to apply to more general Orlicz-Sobolev, Lorentz-Sobolev, and Lorentz-Karamata-Sobolev spaces.peerReviewe

Unintentional Long-Term Esophageal Stenting due to a Complete Response in a Patient with Stage UICC IV Adenocarcinoma of the Gastroesophageal Junction

Endoscopic stent implantation is a common short-treatment option in palliative settings in patients with esophageal cancer. Advanced disease is associated with low survival rates; therefore, data on the long-term outcome are limited. So far, cases of long-term remission or even cure of metastasized adenocarcinoma of the gastroesophageal junction or stomach (AGS) have only been reported from Asia. A 51-year-old male patient primarily diagnosed with metastasized adenocarcinoma of the gastroesophageal junction (GEJ) [type I, cT3cN+cM1 (hep), CEA positive, UICC stage IV] received palliative esophageal stenting with a self-expandable metal stent. As disease progressed after four cycles with epirubicin, oxaliplatin, and capecitabin, treatment was changed to 5-FU and Irinotecan. The patient did not return after 5 cycles of FOLFIRI, but presented 4 years later with mild dysphagia. Endoscopy surprisingly revealed no relevant stenosis or stent migration. Repeated histological analyses of a residual mass at the GEJ did not detect malignancy. Since the initially diagnosed hepatic metastases were no longer detectable by computed tomography, cure from esophageal cancer was assumed. Dysphagia was ascribed to esophageal motility disorder by a narrowed esophageal lumen after long-term stenting. Thus, endoscopic stent implantation is an important method in palliative treatment of dysphagia related to AGS. New systemic treatment strategies like trastuzumab in Her2neu positive cases or new VEGF-inhibitors like ramucirumab will lead to more long-time survivors with AGS. In conclusion, future endoscopic treatment strategies in AGS represent a challenge for the development of new stent techniques in either extraction or programmed complete dissolution