Quantum Informational Dark Energy: Dark energy from forgetting

We suggest that dark energy has a quantum informational origin. Landauer's principle associated with the erasure of quantum information at a cosmic horizon implies the non-zero vacuum energy having effective negative pressure. Assuming the holographic principle, the minimum free energy condition, and the Gibbons-Hawking temperature for the cosmic event horizon we obtain the holographic dark energy with the parameter $d\simeq 1$, which is consistent with the current observational data. It is also shown that both the entanglement energy and the horizon energy can be related to Landauer's principle.Comment: revtex,8 pages, 2 figures more detailed arguments adde

Comparison of Spatial Interpolation Techniques Using Visualization and Quantitative Assessment

Spatial interpolation has been widely and commonly used in many studies to create surface data based on a set of sampled points, such as soil properties, temperature, and precipitation. Currently, there are many commercial Geographic Information System (GIS) or statistics software offering spatial interpolation functions, such as inverse distance weighted (IDW), kriging, spline, and others. To date, there is no “rule of thumb” on the most appropriate spatial interpolation techniques for certain situations, though general suggestions have been published. Many studies rely on quantitative assessment to determine the performance of spatial interpolation techniques. Most quantitative assessment methods provide a numeric index for the overall performance of an interpolated surface. Although it is objective and convenient, there are many facts or trends not captured by quantitative assessments. This study used 2D visualization and 3D visualization to identify trends not evident in quantitative assessment. This study also presented a special case, a closed system in which all interpolated surfaces should sum up to 100%, to demonstrate the interaction between interpolated surfaces that were created separately and independently

Risk factors for hepatitis E infection in renal transplant recipients

Hintergrund. Eine Infektion mit dem Hepatitis-E-Virus (HEV) führt bei immunkompromittierten Patient*innen nach Nierentransplantation in über 50% der Fälle zur Chronifizierung (Dauer > 3 Monate). Ziel dieser explorativen Arbeit war es, Risikofaktoren für chronische HEV-Verläufe zu identifizieren und Prädiktoren für den erfolgreichen Einsatz von Ribavirin zu bestimmen. Methodik. Bei dieser Arbeit handelt es sich um eine retrospektive Datenanalyse von 59 Patient*innen nach Nierentransplantation mit nachgewiesener HEV-Infektion. Diese wurden mit einer Vergleichskohorte (n = 251) mit Nachweis erhöhter Leberwerte mit Ausschluss einer akuten oder chronischen HEV-Infektion verglichen. Die Nahrungsexposition der Patient*innen vor dem Krankheitsausbruch oder der Diagnosestellung wurde ausgewertet. Ergebnisse. Nur 12 (20,3%) Patient*innen erreichten eine Remission ohne zusätzliche Behandlung mit Ribavirin. Von den 46 Patient*innen, die mit Ribavirin therapiert wurden, erlitten 17 Patient*innen (37%) entweder einen Virusrelaps nach Abschluss der Behandlung oder erreichten keine vollständige Viruselimination. Risikofaktoren für eine HEV-Infektion waren eine zurückliegende intensivere Immunsuppression in Form einer Kortisonstoßtherapie (OR: 2,1; p = 0,025) und das männliche Geschlecht dar (OR: 3,2; p = 0,001). Der Einsatz von Cyclosporin A statt Tacrolimus im Rahmen einer Calcineurininhibitor-basierten Therapie war mit einer niedrigeren Rate von HEV-Infektion assoziiert (OR: 0,2; p = 0,022). Während der HEV- Infektion kam es häufiger zu Anstiegen der Proteinurie als in der Kontrollkohorte (p = 0,009) und zu einem signifikanten Abfall der GFR von durchschnittlich -8,8 ml/min während des chronischen Infektionsverlaufs (p = 0,012). Während junges Erwachsenenalter (< 40 Jahre) ein Prädiktor für eine erfolgreiche Therapie mit Ribavirin darstellt (p = 0,036), erwies sich ein BMI 20 kg/m2 als Risikofaktor für eine persistierende rezidivierende HEV-Infektion (p = 0,012). Unter Ribavirintherapie wurde die hämolytische Anämie als hauptsächliche Nebenwirkung beobachtet und galt als prädiktiver Vorhersagewert für ein Therapieversagen (p = 0,035). Beim Vergleich von Ernährungsgewohnheiten mit der Kontrollkohorte war der Verzehr von Kochpökelwaren vom Schwein und Brühwurstaufschnitten mit einem höheren Risiko für eine HEV-Infektion assoziiert (OR 3,4 und 4,2; p = 0,048 und 0,027). Die Patient*innen gaben zusätzlich an, im Haushalt häufiger rohes Fleisch mit bloßen Händen zu verarbeiteten als die Kontrollgruppe (OR 5,3; p = 0,048). Schlussfolgerungen. Die Einhaltung klarer Ernährungsempfehlungen nach Nierentransplantation und der Einfluss immunsupprimierender Medikamente tragen maßgeblich zur Empfänglichkeit einer HEV-Infektion bei. Eine HEV-Infektion ist mit einer Verschlechterung der Nierentransplantatfunktion assoziiert. Patient*innen- spezifische Faktoren wie BMI, Alter und Geschlecht tragen zum höheren Risiko einer HEV-Infektion bei.Background. An infection with Hepatitis E virus (HEV) leads to chronicity (duration > 3 months) in more than 50% of immunocompromised patients after renal transplantation. The aim of this exploratory work was to identify risk factors for chronic HEV courses and to determine predictors for the successful use of ribavirin. Methods. This work is a retrospective data analysis of patients after kidney transplantation with proven HEV infection. Patients with evidence of elevated liver enzymes with exclusion of acute or chronic HEV infection were used as a comparison cohort. Patients' dietary exposure prior to disease onset or diagnosis was evaluated. Results. Only 12 (20.3%) patients achieved remission without additional ribavirin treatment. Of the 46 patients treated with ribavirin, 17 patients (37%) either relapsed after treatment or did not achieve complete viral elimination. Significant risk factors for HEV infection included a history of intensive immunosuppression in the form of cortisone boost therapy (OR: 2.1; p = 0.025) and male gender as a host factor (OR: 3.2; p = 0.001). The use of cyclosporine A instead of tacrolimus in the context of calcineurin inhibitor-based therapy was associated with less frequent occurrence of HEV infection (OR: 0.2; p = 0.022). We observed a higher proportion of proteinuria increases in the HEV cohort compared to the control cohort (p = 0.009) and a significant decrease in GFR of -8.8 ml/min on average during the chronic infection course (p = 0.012). While young adulthood (< 40 years) was a predictor of successful therapy with ribavirin (p = 0.036), a BMI 20 kg/m2 proved to be a risk factor for persistent recurrent HEV infection (p = 0.012). Under ribavirin therapy, hemolytic anemia was observed as the main adverse event and was considered predictive of treatment failure (p = 0.035). In the context of dietary habits, occasional consumption of cooked pork cured meats and cooked sausage slices was associated with a higher risk of HEV infection (OR 3.4 and 4.2; p = 0.048 and 0.027). Patients additionally reported processing raw meat with bare hands in the household more frequently than controls (OR 5.3; p = 0.048). Conclusions. Adherence to clear dietary recommendations after renal transplantation and the influence of immunosuppressive drugs contribute significantly to the susceptibility of HEV infection. In addition, this study provides evidence that host- specific factors critically influence disease progression

Pulse Compression Probing for Tracking Distribution Feeder Models

A Pulse-Compression Probing (PCP) method is applied in time-domain to identify an equivalent circuit model of a distribution network as seen from the transmission grid. A Pseudo-Random Binary Pulse Train (PRBPT) is injected as a voltage signal at the input of the feeder and processed to recover the impulse response. A transfer function and circuit model is fitted to the response, allowing the feeder to be modeled as a quasi-steady-state sinusoidal (QSSS) source behind a network. The method is verified on the IEEE 13-Node Distribution Test System, identifying a second order circuit model with less than seven cycles latency and a signal to noise ratio of 15.07 dB in the input feeder current.Comment: 5 Pages, 6 Figures, Pending Publication at IEEE PESGM 202

Fault-Tolerant Control of a Distributed Database System

Optimal state information-based control policy for a distributed database system subject to server failures is considered. Fault-tolerance is made possible by the partitioned architecture of the system and data redundancy therein. Control actions include restoration of lost data sets in a single server using redundant data sets in the remaining servers, routing of queries to intact servers, or overhaul of the entire system for renewal. Control policies are determined by solving Markov decision problems with cost criteria that penalize system unavailability and slow query response. Steady-state system availability and expected query response time of the controlled database are evaluated with the Markov model of the database. Robustness is addressed by introducing additional states into the database model to account for control action delays and decision errors. A robust control policy is solved for the Markov decision problem described by the augmented state model