Is electronic cash possible?

Cash-like payments in electronic commerce and at the traditional point of sale are expected to be beneficial, e.g., because of privacy protection, low transaction costs, and irrevocability. Therefore, we discuss how to design electronic cash in a way that it both mirrors the most important characteristics of raditional cash, but also fulfils the expectations which arise towards electronic means of payment. We analyse the problems and trade-offs between the different characteristics to be implemented. This analysis is based on a user survey and a review of existing technologies for electronic payment systems. Finally we argue why existing systems do not fulfil the critical requirements, and point out future work towards electronic cash which will meet more requirements

Delay of total joint replacement is associated with a higher 90-day revision rate and increased postoperative complications

Purpose Delay of elective surgeries, such as total joint replacement (TJR), is a common procedure in the current pandemic. In trauma surgery, postponement is associated with increased complication rates. This study aimed to evaluate the impact of postponement on surgical revision rates and postoperative complications after elective TJR. Methods In a retrospective analysis of 10,140 consecutive patients undergoing primary total hip replacement (THR) or total knee replacement (TKR) between 2011 and 2020, the effect of surgical delay on 90-day surgical revision rate, as well as internal and surgical complication rates, was investigated in a university high-volume arthroplasty center using the institute’s joint registry and data of the hospital administration. Moreover, multivariate logistic regression models were used to adjust for confounding variables. Results Two thousand four hundred and eighty TJRs patients were identified with a mean delay of 13.5 ± 29.6 days. Postponed TJR revealed a higher 90-day revision rate (7.1–4.5%, p < 0.001), surgical complications (3.2–1.9%, p < 0.001), internal complications (1.8–1.2% p < 0.041) and transfusion rate (2.6–1.8%, p < 0.023) than on-time TJR. Logistic regression analysis confirmed delay of TJRs as independent risk factor for 90-day revision rate [OR 1.42; 95% CI (1.18–1.72); p < 0.001] and surgical complication rates [OR 1.51; 95% CI (1.14–2.00); p = 0.04]. Conclusion Alike trauma surgery, delay in elective primary TJR correlates with higher revision and complication rates. Therefore, scheduling should be performed under consideration of the current COVID-19 pandemic. Level of evidence Level III—retrospective cohort study

Outcome nach Gelenkersatz bei Patienten mit rheumatoider Grunderkrankung

Hintergrund Der künstliche Gelenkersatz ist für Patienten mit fortgeschrittenen rheumatisch degenerativen Gelenkveränderungen eine sinnvolle Therapieoption. Ziel dieser Studie war es, den Einfluss rheumatischer Grunderkrankungen auf postoperative Komplikationen und „patient-reported outcome“ (PRO) nach elektivem Gelenkersatz („total joint replacement“ [TJR]) zu untersuchen. Materialien und Methoden In einer retrospektiven Analyse von 9149 Patienten nach elektiver Knie- oder Hüfttotalendoprothesenimplantation (TKR und THR) wurden Komplikationsraten und PRO von Patienten mit und ohne rheumatische Grunderkrankung („rheumatic disease“ [RD]) verglichen. Multivariate logistische Regressionsmodelle wurden verwendet, um festzustellen, ob rheumatische Grunderkrankungen einen unabhängigen Risikofaktor für verschiedene Komplikationen darstellen. Ergebnisse RD-Patienten hatten nach TJR in den univariaten Analysen ein erhöhtes Risiko für internistische Komplikationen (7,1 % vs. 5,2 %, p = 0,028) und Clavien-Dindo-Grad-IV-Komplikationen (2,8 % vs. 1,8 %, p = 0,048). Dies konnte in multivariaten statistischen Analysen bestätigt werden (p = 0,034). Die Raten für operative Revisionen und chirurgische Komplikationen waren vergleichbar (2,5 % vs. 2,4 %, p = 0,485). Die Analyse des PRO ergab eine höhere Responderrate bei Patienten mit RD nach TKR (91,9 % vs. 84,5 %, p = 0,039). Die Responderrate nach THR war hingegen vergleichbar (93,4 % vs. 93,2 %, p = 0,584). Schlussfolgerung Trotz teilweise erhöhter postoperativer Komplikationsraten zeigen Patienten mit rheumatischer Grunderkrankung 1 Jahr nach Operation ein vergleichbares Outcome nach TJR. RD-Patienten nach TKR zeigen sogar höhere Responderraten. RD-Patienten sind zwar eine vulnerable Patientengruppe, können aber dennoch von einem Gelenkersatz profitieren

Causation, complexity, and the concert: the pragmatics of causal explanation in international relations

A causal explanation provides information about the causal history of whatever is being explained. However, most causal histories extend back almost infinitely and can be described in almost infinite detail. Causal explanations therefore involve choices about which elements of causal histories to pick out. These choices are pragmatic: they reflect our explanatory interests. When adjudicating between competing causal explanations, we must therefore consider not only questions of epistemic adequacy (whether we have good grounds for identifying certain factors as causes) but also questions of pragmatic adequacy (whether the aspects of the causal history picked out are salient to our explanatory interests). Recognizing that causal explanations differ pragmatically as well as epistemically is crucial for identifying what is at stake in competing explanations of the relative peacefulness of the nineteenth-century Concert system. It is also crucial for understanding how explanations of past events can inform policy prescription

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Plasmin Inhibitors Prevent Leukocyte Accumulation and Remodeling Events in the Postischemic Microvasculature

Clinical trials revealed beneficial effects of the broad-spectrum serine protease inhibitor aprotinin on the prevention of ischemia-reperfusion (I/R) injury. The underlying mechanisms remained largely unclear. Using in vivo microscopy on the cremaster muscle of male C57BL/6 mice, aprotinin as well as inhibitors of the serine protease plasmin including tranexamic acid and ε-aminocaproic acid were found to significantly diminish I/R-elicited intravascular firm adherence and (subsequent) transmigration of neutrophils. Remodeling of collagen IV within the postischemic perivenular basement membrane was almost completely abrogated in animals treated with plasmin inhibitors or aprotinin. In separate experiments, incubation with plasmin did not directly activate neutrophils. Extravascular, but not intravascular administration of plasmin caused a dose-dependent increase in numbers of firmly adherent and transmigrated neutrophils. Blockade of mast cell activation as well as inhibition of leukotriene synthesis or antagonism of the platelet-activating-factor receptor significantly reduced plasmin-dependent neutrophil responses. In conclusion, our data suggest that extravasated plasmin(ogen) mediates neutrophil recruitment in vivo via activation of perivascular mast cells and secondary generation of lipid mediators. Aprotinin as well as the plasmin inhibitors tranexamic acid and ε-aminocaproic acid interfere with this inflammatory cascade and effectively prevent postischemic neutrophil responses as well as remodeling events within the vessel wall