Multi-wavelength Diagnostics of the Precursor and Main phases of an M1.8 Flare on 2011 April 22

We study the temporal, spatial and spectral evolution of the M1.8 flare, which occurred in NOAA AR 11195 (S17E31) on 22 April 2011, and explore the underlying physical processes during the precursors and their relation to the main phase. The study of the source morphology using the composite images in 131 {\deg}A wavelength observed by the SDO/AIA and 6-14 keV revealed a multiloop system that destabilized systematically during the precursor and main phases. In contrast, HXR emission (20-50 keV) was absent during the precursor phase, appearing only from the onset of the impulsive phase in the form of foot-points of emitting loop/s. This study has also revealed the heated loop-top prior to the loop emission, although no accompanying foot-point sources were observed during the precursor phase. We estimate the flare plasma parameters viz. T, EM, power-law index, and photon turn-over energy by forward fitting RHESSI spectral observations. The energy released in the precursor phase was thermal and constituted ~1 per cent of the total energy released during the flare. The study of morphological evolution of the filament in conjunction with synthesized T and EM maps has been carried out which reveals (a) Partial filament eruption prior to the onset of the precursor emission, (b) Heated dense plasma over the polarity inversion line and in the vicinity of the slowly rising filament during the precursor phase. Based on the implications from multi-wavelength observations, we propose a scheme to unify the energy release during the precursor and main phase emissions in which, the precursor phase emission has been originated via conduction front formed due to the partial filament eruption. Next, the heated leftover S-shaped filament has undergone slow rise and heating due to magnetic reconnection and finally erupted to produce emission during the impulsive and gradual phases.Comment: 16 Pages, 11 Figures, Accepted for Publication in MNRAS Main Journa

ESCAPADE: Encryption-type-ransomeware: system call based pattern detection

Encryption-type ransomware has risen in prominence lately as the go-to malware for threat actors aiming to compromise Android devices. In this paper, we present a ransomware detection technique based on behaviours observed in the system calls performed by the malware. We identify and present some common high-level system call behavioural patterns targeted at encryption-type ransomware and evaluate these patterns. We further present our repeatable and extensible methodology for extracting the system call log and patterns

Reliability assessment of a smart and compact inverter developed for electrically powered construction vehicles

In this paper reliability investigations on a newly developed inverter for electric construction vehicles will be reported. Focus has been set on mechanical robustness of the system, where virtual prototyping combined with experimental modal analyses have been applied to identify potential weak point and subsequently to derive mitigation actions

Supervised learning reveals circulating biomarker levels diagnostic of hepatocellular carcinoma in a clinically relevant model of non-alcoholic steatohepatitis; An OAD to NASH.

Although cirrhosis is a key risk factor for the development of hepatocellular carcinoma (HCC), mounting evidence indicates that in a subset of patients presenting with non-alcoholic steatohepatitis (NASH) HCC manifests in the absence of cirrhosis. Given the sheer size of the ongoing non-alcoholic fatty liver disease (NAFLD) epidemic and the dismal prognosis associated with late-stage primary liver cancer there is an urgent need for HCC surveillance in the NASH population. Using serum levels of HCC biomarkers as vectors and biopsy-proven HCC or no HCC as outputs / binary classifier, a supervised learning campaign was undertaken to develop a minimally invasive technique for making a diagnosis of HCC in a clinically relevant model of NASH. Adult mice randomized to control diet or a fast food diet (FFD) were followed for up to 14 mo and serum level of a panel of HCC-relevant biomarkers was compared with liver biopsies at 3 and 14 mo. Both NAFLD Activity Score (NAS) and hepatic hydroxyproline content were elevated at 3 and 14 mo on FFD. Picrosirius red staining of liver sections revealed a filigree pattern of fibrillar collagen deposition with no cirrhosis at 14 mo on FFD. Nevertheless, 46% of animals bore one or more tumors on their livers confirmed as HCC in hematoxylin-eosin-stained liver sections. In this training set, receiver operating characteristic (ROC) curves analysis for serum levels of the HCC biomarkers osteopontin (OPN), alpha-fetoprotein (AFP) and Dickkopf-1 (DKK1) returned concordance-statistic/area under ROC curve of ≥ 0.89. Serum levels of OPN (threshold, 218 ng/mL; sensitivity, 82%; specificity, 86%), AFP (136 ng/mL; 91%; 97%) and DKK1 (2.4 ng/mL; 82%; 81%) diagnostic for HCC were confirmed in a test set comprising mice on control diet or FFD and mice subjected to hepatic ischemia-reperfusion injury. These data suggest that levels of circulating OPN, AFP and DKK1 can be used to make a diagnosis of HCC in a clinically relevant model of NASH

Diagnostic performance of HCC biomarkers in test set.

<p>(Top) Representative H&E-stained livers sections (20 X) from a Kcnn4/ KCa3.1 null mice mouse on a control diet (left), a C57BL/6 mouse on FFD for 7 mo (middle) exhibiting steatosis and CD-1 mouse submitted to hepatic ischemia and 24 hr reperfusion (right) exhibiting necroinflammatory injury. There was no evidence of HCC in the test set. (Bottom) Diagnostic accuracy of OPN, AFP and DKK1 in the test set.</p

Liver hydroxyproline.

<p>(Top left) Animals randomized to FFD for 3 mo exhibited ~ 50% higher liver hydroxyproline content compared with animals randomized to a control diet for an equivalent time period (#, p < 0.01 vs. control). (Bottom Left) Animals on FFD for 14 mo but free of HCC had >4-fold higher liver hydroxyproline content than animals on a control diet for the same time interval (#, p < 0.01 vs. control). Liver hydroxyproline content was highest in the 14 mo HCC FFD cohort (*, p < 0.01 vs. FFD). (Right) ROC curve for liver hydroxyproline as a diagnostic for HCC yielded an AUROC of 0.9.</p

ROC curves for HCC biomarkers.

<p>Performance of the biomarkers listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198937#pone.0198937.t001" target="_blank">Table 1</a> as diagnostics for HCC are shown as ROC curves. Only OPN, AFP and DKK1 had AUROCs ≥ 0.8.</p

FFD model of NASH with fibrosis.

<p>(Top) Representative H&E (left) and Picrosirius red (right) stained liver sections (10 X) from an animal on a control diet for 14 mo. (Middle) Representative H&E (left) and Picrosirius red (right) stained liver sections (10 X) from an HCC FFD animal that was on FFD for 14 mo. (Bottom) 20 X section from that animal (left, H&E; right Picrosirius red). While a filigree pattern of Picrosirius red staining was observed in the HCC FFD cohort, there was no histological evidence of cirrhosis.</p

Diagnostic performance of HCC biomarkers.

<p>OPN, AFP and DKK1 each had AUROCs > 0.8 for HCC and exhibited excellent S_n and S_p. Thresholds or cutoffs for each of these biomarkers is listed.</p