On the 3D Reconstruction of Coronal Mass Ejections using Coronagraph Data

Coronal Mass ejections (CMEs) are enormous eruptions of magnetized plasma expelled from the Sun into the interplanetary space, over the course of hours to days. They can create major disturbances in the interplanetary medium and trigger severe magnetic storms when they col- lide with the Earth’s magnetosphere. It is important to know their real speed, propagation direction and 3D configura- tion in order to accurately predict their arrival time at the Earth. Using data from the SECCHI coronagraphs onboard the STEREO mission, which was launched in October 2006, we can infer the propagation direction and the 3D struc- ture of such events. In this review, we first describe differ- ent techniques that were used to model the 3D configuration of CMEs in the coronagraph field of view (up to 15 R⊙). Then, we apply these techniques to different CMEs observed by various coronagraphs. A comparison of results obtained from the application of different reconstruction algorithms is presented and discussed

Determination of reliability criteria for liver stiffness evaluation by transient elastography

UNLABELLED: Liver stiffness evaluation (LSE) is usually considered as reliable when it fulfills all the following criteria: ≥10 valid measurements, ≥60% success rate, and interquartile range / median ratio (IQR/M) ≤0.30. However, such reliable LSE have never been shown to be more accurate than unreliable LSE. Thus, we aimed to evaluate the relevance of the usual definition for LSE reliability, and to improve reliability by using diagnostic accuracy as a primary outcome in a large population. 1,165 patients with chronic liver disease from 19 French centers were included. All patients had liver biopsy and LSE. 75.7% of LSE were reliable according to the usual definition. However, these reliable LSE were not significantly more accurate than unreliable LSE with, respectively: 85.8% versus 81.5% well-classified patients for the diagnosis of cirrhosis (P = 0.082). In multivariate analyses with different diagnostic targets, LSE median and IQR/M were independent predictors of fibrosis staging, with no significant influence of ≥10 valid measurements or LSE success rate. These two reliability criteria determined three LSE groups: "very reliable" (IQR/M ≤0.10), "reliable" (0.10< IQR/M ≤0.30, or IQR/M >0.30 with LSE median <7.1 kPa), and "poorly reliable" (IQR/M >0.30 with LSE median ≥7.1 kPa). The rates of well-classified patients for the diagnosis of cirrhosis were, respectively: 90.4%, 85.8%, and 69.5% (P < 10(-3) ). According to these new reliability criteria, 9.1% of LSE were poorly reliable (versus 24.3% unreliable LSE with the usual definition, P < 10(-3) ), 74.3% were reliable, and 16.6% were very reliable. CONCLUSION: The usual definition for LSE reliability is not relevant. LSE reliability depends on IQR/M according to liver stiffness median level, defining thus three reliability categories: very reliable, reliable, and poorly reliable LSE. (HEPATOLOGY 2013)

Radiologic versus Endoscopic Placement of Percutaneous Gastrostomy in Amyotrophic Lateral Sclerosis: Multivariate Analysis of Tolerance, Efficacy, and Survival

PurposeTo compare percutaneous radiologic gastrostomy (PRG) and percutaneous endoscopic gastrostomy (PEG) in terms of tolerance, efficacy, and survival in patients with amyotrophic lateral sclerosis (ALS). Materials and Methods Forty patients with ALS (17 men; mean age, 66.1 years; range, 39–83 y) underwent 21 PEG and 22 PRG attempts (including three unsuccessful PEG attempts) from 1999 to 2005. To assess tolerance and efficacy, a successful and well tolerated placement was defined as any successful placement with no major or minor local complications or pain requiring opioid analgesic agents. Univariate analysis was performed for all recorded parameters, followed by multivariate analysis for successful and well tolerated placement, 6-month mortality rate, and survival. Results General success rates were 85.7% for PEG and 100% for PRG. Pain was more frequent in PRGs (81.8% vs 52.4%; P = .05). Successful and well tolerated placement was seen in 81.8% of PRGs and 57.1% of PEGs (P = 0.1). Advanced age (P = .02) and PRG (P = .07) were predictive of successful and well tolerated placement. The interval from diagnosis to placement (P = .001) and ability to perform spirometry (P = .002) were predictive of survival. Oximetry measurements (P = .007) and interval from diagnosis to placement (P = .02) were predictive of mortality at 6 months. Conclusions PRG is more efficacious and better tolerated than PEG, essentially because it avoids the respiratory decompensation that may occur in PEG. Therefore, PRG should be preferred in cases of ALS. Survival is linked to ALS evolution and not to the choice of PRG or PEG placement

Proceedings of the second "international Traveling Workshop on Interactions between Sparse models and Technology" (iTWIST'14)

The implicit objective of the biennial "international - Traveling Workshop on Interactions between Sparse models and Technology" (iTWIST) is to foster collaboration between international scientific teams by disseminating ideas through both specific oral/poster presentations and free discussions. For its second edition, the iTWIST workshop took place in the medieval and picturesque town of Namur in Belgium, from Wednesday August 27th till Friday August 29th, 2014. The workshop was conveniently located in "The Arsenal" building within walking distance of both hotels and town center. iTWIST'14 has gathered about 70 international participants and has featured 9 invited talks, 10 oral presentations, and 14 posters on the following themes, all related to the theory, application and generalization of the "sparsity paradigm": Sparsity-driven data sensing and processing; Union of low dimensional subspaces; Beyond linear and convex inverse problem; Matrix/manifold/graph sensing/processing; Blind inverse problems and dictionary learning; Sparsity and computational neuroscience; Information theory, geometry and randomness; Complexity/accuracy tradeoffs in numerical methods; Sparsity? What's next?; Sparse machine learning and inference.Comment: 69 pages, 24 extended abstracts, iTWIST'14 website: http://sites.google.com/site/itwist1

Practical diagnosis of cirrhosis in non-alcoholic fatty liver disease using currently available non-invasive fibrosis tests

Unlike for advanced liver fibrosis, the practical rules for the early non-invasive diagnosis of cirrhosis in NAFLD remain not well defined. Here, we report the derivation and validation of a stepwise diagnostic algorithm in 1568 patients with NAFLD and liver biopsy coming from four independent cohorts. The study algorithm, using first the elastography-based tests Agile3+ and Agile4 and then the specialized blood tests FibroMeterV3G and CirrhoMeterV3G, provides stratification in four groups, the last of which is enriched in cirrhosis (71% prevalence in the validation set). A risk prediction chart is also derived to allow estimation of the individual probability of cirrhosis. The predicted risk shows excellent calibration in the validation set, and mean difference with perfect prediction is only −2.9%. These tools improve the personalized non-invasive diagnosis of cirrhosis in NAFLD

Quantification of portal–bridging fibrosis area more accurately reflects fibrosis stage and liver stiffness than whole fibrosis or perisinusoidal fibrosis areas in chronic hepatitis C

International audienceMorphometry provides an objective evaluation of fibrosis in liver diseases. We developed an image analysis algorithm using automated thresholding and segmentation to separately quantify the areas and the fractal dimensions of portal–bridging fibrosis and perisinusoidal fibrosis in chronic hepatitis C liver biopsies. We studied 427 digitized liver biopsies and compared the automated measures of the different fibrosis compartments with (1) the Metavir F (fibrosis) and A (activity) histological scores, (2) the digitally assessed area of steatosis, and (3) the liver stiffness measured by elastography (Fibroscan). The perisinusoidal fibrosis area was higher than that of portal fibrosis in stages ≤F2; it reached its highest value in F2 stage and stabilized thereafter. The F3 stage was characterized by equal proportions of portal–bridging and perisinusoidal fibrosis, whereas portal–bridging area was predominant in cirrhosis. Measurement of portal–bridging fibrosis showed highly significantly different values between contiguous F stages; the ratio of portal–bridging fibrosis/perisinusoidal fibrosis displayed less overlap between Metavir stages than did the whole fibrosis area values. Fractal dimension showed that portal–bridging fibrosis tended to display a homogeneous surface-like spatial organization, whereas perisinusoidal fibrosis appeared more heterogeneous according to stage and curvilinear. The portal–bridging fibrosis area was low in cases with low Metavir activity and little steatosis, and became predominant with increasing activity and steatosis. Using stepwise multiple linear regression analysis, the liver stiffness was independently correlated to the portal–bridging fibrosis area (first step, P<0.001), the steatosis area (second step, P<0.001), and the Metavir A grade (third step, P=0.001), but not to the perisinusoidal fibrosis area. Automated quantification in a large cohort of chronic hepatitis C showed that perisinusoidal fibrosis progressively grew in early fibrosis stages but did not increase in septal or cirrhotic stages and that the portal–bridging fibrosis area appeared as a more accurate tool to assess fibrosis progression than the whole fibrosis area

Superconductivity in Ce- and U-based "122" heavy-fermion compounds

This review discusses the heavy-fermion superconductivity in Ce- and U-based compounds crystallizing in the body-centered tetragonal ThCr2Si2 structure. Special attention will be paid to the theoretical background of these systems which are located close to a magnetic instability.Comment: 12 pages, 9 figures. Invited topical review (special issue on "Recent Developments in Superconductivity") Metadata and references update

Liver stiffness in nonalcoholic fatty liver disease: A comparison of supersonic shear imaging, FibroScan, and ARFI with liver biopsy

Nonalcoholic fatty liver disease (NAFLD) has become a major public health issue. The goal of this study was to assess the clinical use of liver stiffness measurement (LSM) evaluated by supersonic shear imaging (SSI), FibroScan, and acoustic radiation force impulse (ARFI) in a cohort of NAFLD patients who underwent liver biopsy. A total of 291 NAFLD patients were prospectively enrolled from November 2011 to February 2015 at 2 French university hospitals. LSM was assessed by SSI, FibroScan (M probe), and ARFI within two weeks prior to liver biopsy. Calculations of the area under the receiver operating curve (AUROC) were performed and compared for the staging of liver fibrosis. AUROC for SSI, FibroScan, and ARFI were 0.86, 0.82, and 0.77 for diagnoses of ≥F2; 0.89, 0.86, and 0.84 for ≥F3; and 0.88, 0.87, and 0.84 for F4, respectively. SSI had a higher accuracy than ARFI for diagnoses of significant fibrosis (≥F2) (P = 0.004). Clinical factors related to obesity such as body mass index ≥ 30 kg/m(2) , waist circumference ≥102 cm or increased parietal wall thickness were associated with LSM failures when using SSI or FibroScan and with unreliable results when using ARFI. In univariate analysis, FibroScan values were slightly correlated with NAFLD activity score and steatosis (R = 0.28 and 0.22, respectively), whereas SSI and ARFI were not; however, these components of NAFLD did not affect LSM results in multivariate analysis. The cutoff values for SSI and FibroScan for staging fibrosis with a sensitivity ≥90% were very close: 6.3/6.2 kPa for ≥F2, 8.3/8.2 kPa for ≥F3, and 10.5/9.5 kPa for F4. CONCLUSION: Although obesity is associated with an increase in LSM failure, the studied techniques and especially SSI provide high value for the diagnosis of liver fibrosis in NAFLD patients. (Hepatology 2016;63:1817-1827)

Reduced lipoapoptosis, hedgehog pathway activation and fibrosis in caspase-2 deficient mice with non-alcoholic steatohepatitis

OBJECTIVE: Caspase-2 is an initiator caspase involved in multiple apoptotic pathways, particularly in response to specific intracellular stressors (eg, DNA damage, ER stress). We recently reported that caspase-2 was pivotal for the induction of cell death triggered by excessive intracellular accumulation of long-chain fatty acids, a response known as lipoapoptosis. The liver is particularly susceptible to lipid-induced damage, explaining the pandemic status of non-alcoholic fatty liver disease (NAFLD). Progression from NAFLD to non-alcoholic steatohepatitis (NASH) results, in part, from hepatocyte apoptosis and consequential paracrine-mediated fibrogenesis. We evaluated the hypothesis that caspase-2 promotes NASH-related cirrhosis. DESIGN: Caspase-2 was localised in liver biopsies from patients with NASH. Its expression was evaluated in different mouse models of NASH, and outcomes of diet-induced NASH were compared in wild-type (WT) and caspase-2-deficient mice. Lipotoxicity was modelled in vitro using hepatocytes derived from WT and caspase-2-deficient mice. RESULTS: We showed that caspase-2 is integral to the pathogenesis of NASH-related cirrhosis. Caspase-2 is localised in injured hepatocytes and its expression was markedly upregulated in patients and animal models of NASH. During lipotoxic stress, caspase-2 deficiency reduced apoptosis, inhibited induction of profibrogenic hedgehog target genes in mice and blocked production of hedgehog ligands in cultured hepatocytes. CONCLUSIONS: These data point to a critical role for caspase-2 in lipid-induced hepatocyte apoptosis in vivo for the production of apoptosis-associated fibrogenic factors and in the progression of lipid-induced liver fibrosis. This raises the intriguing possibility that caspase-2 may be a promising therapeutic target to prevent progression to NASH