Induction of Type I Interferon Signaling Determines the Relative Pathogenicity of Staphylococcus aureus Strains

The tremendous success of S. aureus as a human pathogen has been explained primarily by its array of virulence factors that enable the organism to evade host immunity. Perhaps equally important, but less well understood, is the importance of the intensity of the host response in determining the extent of pathology induced by S. aureus infection, particularly in the pathogenesis of pneumonia. We compared the pathogenesis of infection caused by two phylogenetically and epidemiologically distinct strains of S. aureus whose behavior in humans has been well characterized. Induction of the type I IFN cascade by strain 502A, due to a NOD2-IRF5 pathway, was the major factor in causing severe pneumonia and death in a murine model of pneumonia and was associated with autolysis and release of peptidogylcan. In contrast to USA300, 502A was readily eliminated from epithelial surfaces in vitro. Nonetheless, 502A caused significantly increased tissue damage due to the organisms that were able to invade systemically and trigger type I IFN responses, and this was ameliorated in Ifnar-/- mice. The success of USA300 to cause invasive infection appears to depend upon its resistance to eradication from epithelial surfaces, but not production of specific toxins. Our studies illustrate the important and highly variable role of type I IFN signaling within a species and suggest that targeted immunomodulation of specific innate immune signaling cascades may be useful to prevent the excessive morbidity associated with S. aureus pneumonia

Design and experimental verification of a 50 kW interior permanent magnet synchronous machine

This paper presents the design details for an IPM machine designed to deliver 50 kW constant power over a 5:1 speed range extending from 850 rpm to 4250 rpm, with a gradual reduction in the required output power up to 8000 rpm (25 kW). Electromagnetic, thermal, and structural considerations have been included in the design optimization process. The resulting machine is designed with two magnet layers per pole and a distributed stator winding. Special features of the machine include its deep stator slots and four-layer winding, made necessary by the desire to minimize the machine's moment of inertia. Test results available to date demonstrate that the machine is capable of delivering the required output torque and power, and the agreement between the predicted and measured machine parameters is generally quite good. Calculated iron losses for high-speed flux-weakening operation are presented in the final section of the paper, illustrating the challenges associated with minimizing the impact of high-frequency harmonic flux density components.Jahns, T.M.; Seok-Hee Han; El-Refaie, A.M.; Jei-Hoon Baek; Aydin, M.; Guven, M.K.; Soong, W.L

A New Time Series Similarity Measure and Its Smart Grid Applications

Many smart grid applications involve data mining, clustering, classification, identification, and anomaly detection, among others. These applications primarily depend on the measurement of similarity, which is the distance between different time series or subsequences of a time series. The commonly used time series distance measures, namely Euclidean Distance (ED) and Dynamic Time Warping (DTW), do not quantify the flexible nature of electricity usage data in terms of temporal dynamics. As a result, there is a need for a new distance measure that can quantify both the amplitude and temporal changes of electricity time series for smart grid applications, e.g., demand response and load profiling. This paper introduces a novel distance measure to compare electricity usage patterns. The method consists of two phases that quantify the effort required to reshape one time series into another, considering both amplitude and temporal changes. The proposed method is evaluated against ED and DTW using real-world data in three smart grid applications. Overall, the proposed measure outperforms ED and DTW in accurately identifying the best load scheduling strategy, anomalous days with irregular electricity usage, and determining electricity users' behind-the-meter (BTM) equipment.Comment: 7 pages, 6 figures conferenc

Relativistic effects and two-body currents in 2H(e⃗,e′p)n^{2}H(\vec{e},e^{\prime}p)n using out-of-plane detection

Measurements of the ${^2}H(\vec{e},e^{\prime}p)n$ reaction were performed using an 800-MeV polarized electron beam at the MIT-Bates Linear Accelerator and with the out-of-plane magnetic spectrometers (OOPS). The longitudinal-transverse, $f_{LT}$ and $f_{LT}^{\prime}$, and the transverse-transverse, $f_{TT}$, interference responses at a missing momentum of 210 MeV/c were simultaneously extracted in the dip region at Q$^2$=0.15 (GeV/c)$^2$. On comparison to models of deuteron electrodisintegration, the data clearly reveal strong effects of relativity and final-state interactions, and the importance of the two-body meson-exchange currents and isobar configurations. We demonstrate that these effects can be disentangled and studied by extracting the interference response functions using the novel out-of-plane technique.Comment: 4 pages, 4 figures, and submitted to PRL for publicatio

The diagnostic value of SPECT/CT in predicting the occurrence of osteonecrosis following femoral neck fracture: a prospective cohort study

Abstract Backgrounds One of the most significant complications after a femoral neck fracture is osteonecrosis of the femoral head (ONFH). The concomitant use of single-photon emission computed tomography (SPECT) with computed tomography (CT) increases the sensitivity for detecting the anatomic location and severity of ONFH. In this study, we evaluated the diagnostic value of SPECT/CT for the occurrence of ONFH by quantifying the perfusion status of the femoral head. Methods A total of 30 patients who had multiple pinnings for femur neck fractures were included in this study. We classified the perfusion status into three groups: normal perfusion, decreased perfusion, and avascular groups, and compared the occurrence of femoral head necrosis between them. For quantitative analysis, we evaluated the uptake ratio of both femur heads (head-to-head uptake ratio). If the patients contralateral hip was incomparable, we measured the uptake ratio from the superior dome of the ipsilateral acetabulum (head-to-acetabulum uptake ratio). Results Twenty-four patients out of 30 achieved bone union, whereas the others developed ONFH. When the population was divided into intact and defective perfusion groups on scintigraphy, the sensitivity, specificity, and accuracy of the test were 83.3, 75.0, and 76.7%, respectively. The mean head-to-head uptake ratio value with a 95% confidence interval (CI) was 1.10 (95% CI: 0.85–1.36). In the osteonecrosis group, the mean value of the head-to-head uptake ratio was 0.33 (95% CI: 0.28–0.38). In contrast, the ratio was 1.30 (95% CI: 1.03–1.57) in the non-osteonecrosis group, demonstrating a significant difference in the uptake ratio (P <0.001). When the cutoff value of the uptake ratio was set to 0.5, both the sensitivity and specificity were 100%. There was also a significant difference in the head-to-acetabulum uptake ratio between the two groups (P < 0.001). Conclusions SPECT/CT was useful in evaluating the perfusion status of the femoral head, showing high accuracy in predicting the occurrence of avascular necrosis. To demonstrate the reliability and validity of SPECT/CT, further prospective studies on a larger scale are warranted