Surface deformation time series and source modeling for a volcanic complex system based on satellite wide swath and image mode interferometry: The Lazufre system, central Andes

The variable spatio-temporal scales of Earth's surface deformation in potentially hazardous volcanic areas pose a challenge for observation and assessment. Here we used Envisat data acquired in Wide Swath Mode (WSM) and Image Mode (IM) from ascending and descending geometry, respectively, to study time-dependent ground uplift at the Lazufre volcanic system in Chile and Argentina. A least-squares adjustment was performed on 65 IM interferograms that covered the time period of 2003-2008. We obtained a clear trend of uplift reaching 15-16 cm in this 5-year interval. Using a joint inversion of ascending and descending interferograms, we evaluated the geometry and time-dependent progression of a horizontally extended pressurized source beneath the Lazufre volcanic system. Our results hence indicate that an extended magma body at a depth between 10 and 15 km would account for most of the ground uplift. The maximum inflation reached up to ~ 40 cm during 2003-2008. The lateral propagation velocity of the intrusion was estimated to be nearly constant at 5-10 km/yr during the observation time, which has important implications for the physical understanding of magma intrusion processes.     

Transformation of austenite into bainitic ferrite and martensite

The stress induced martensitic transformation in the upper metastable intermediate state of γ-α transformation in ferrous materials, structured as ferritic bainite, is discussed. The fibrous structured ferritic bainite consists of retained austenite and ferrite platelets growing in the [111]α//[101]γ direction. The ferrite growth Induces carbon enrichment of the adjacent austenite at the phase boundaries. Strengthening at high stress levels up to the yield point causes dislocation tangles in the ferrite fibre and the formation of shear bands crossing each other in the retained austenite. At lower carbon contents of the austenite, lath martensite precipitates at the shear band intersections and at high shear band densities martensite blocks are observed. In carbon enriched austenite martensite lenses formed by shear processes have been observed. At alternating loading conditions, exceeding the stress level for athermic martensite formation, various shear planes are activated forming characteristic patterns of plate martensite.     

Naming decline after left anterior temporal lobectomy correlates with pathological status of resected hippocampus

PURPOSE: To evaluate the determinants of postoperative change in visual confrontation naming ability and the differential sensitivity of two common tests of confrontation naming. METHODS: In a group of 99 patients undergoing lobectomy of the left, language-dominant anterior temporal lobe, we examined naming ability using two measures: the 60 item Boston Naming Test (BNT), and the Visual Naming (VN) subtest of the Multilingual Aphasia Examination (MAE). ATL entailed resection of lateral temporal lobe followed by microsurgical complete removal of hippocampus. Language mapping was not performed. The status of the resected hippocampus was graded on a scale 0-4 of hippocampal sclerosis (HS). A dichotomous grouping HS- (grades 0 and 1, n = 34) and HS+ (grades 3 and 4, n = 61) was effected. Age at surgery, age of epilepsy onset, sex, extent of lateral temporal resection, Full-Scale IQ (FSIQ), and preoperative naming scores were also examined as potential predictors of pre- versus postoperative naming change. RESULTS: Preoperative BNT and VN scores were significantly worse for HS+ than for HS- (BNT, p < 0.05; VN, p = 0.001). Postoperatively, BNT and VN scores significantly declined for HS- as compared with HS+ patients (p < 0.001). For individual risk, the 90th centile of reliable change index (RCI) was used. By this criterion, of the total sample, 39% evidenced decline on the BNT and 17% evidenced decline on the VN. Logistic regression analysis with backward elimination showed HS to be the only predictor of decline in BNT and HS and sex to be the only predictors of VN decline. Males were more at risk than females. Age, age at onset, extent of lateral resection, preoperative scores, and FSIQ were not predictors. Using age at onset as a proxy for HS+/HS- we calculated probabilities for naming decline for given onset age. CONCLUSIONS: Both preoperative and postoperative change in naming ability are associated with the pathological status of the hippocampus. The potential interpretations and implications of these findings are discussed.     

Apoptosis of endothelial cells. Contribution to the pathophysiology of atherosclerosis?

Endothelial cell injury is a key event in the pathogenesis of atherosclerosis. Importantly, endothelial cells in lesion-prone regions, where atherosclerotic lesions preferentially develop, are characterised by increased endothelial cell turn-over rates suggesting a mechanistic link between endothelial cell turn-over with preceding cell death and the susceptibility to atherosclerotic plaque development. The activation of the cellular suicide pathway leading to apoptosis of the endothelial cell may be an initial step in the development of atherosclerotic lesions. This hypothesis is supported by the finding that proatherosclerotic factors such as angiotensin II, oxidized low density lipoprotein, reactive oxygen species, glucose and inflammatory cytokines have all been shown to induce apoptosis of endothelial cells. In contrast, the known atheroprotective factors, such as oestrogen, nitric oxide or anti-oxidants, prevented endothelial cell apoptosis. Furthermore, laminar flow, which seems to be one of the most potent endogenous anti-atherosclerotic factor as illustrated by the focal nature of atherosclerotic lesion development in areas with turbulent or low blood flow, protects endothelial cell from apoptotic cell death. The present article summarizes the effects of pro and anti-atherosclerotic factors on endothelial cell apoptosis and provides insights into the underlying signalling events.     

Learned helplessness, attributional style, and depression in epilepsy. Bozeman Epilepsy Surgery Consortium

PURPOSE: We wished to examine the relevance of the theory of learned helplessness in general, and attributional style in particular, to the understanding of depression among patients with epilepsy. METHODS: Patients with lateralized temporal lobe epilepsy (TLE) (right = 73, left = 70) were administered two self-report depression inventories [Beck Depression Inventory (BDI), Center for Epidemiological Studies-Depression scale (CES-D)]. Depression scores were examined in relation to a key component of the revised theory of learned helplessness (attributional style) using the Optimism/Pessimism Scale. RESULTS: Attributional style was significantly associated with increased self-reported depression and remained significant when the effects of several confounding variables were controlled [age, age at onset, laterality of TLE, sex, and method variance]. CONCLUSIONS: The results indicate that the concept of learned helplessness in general, and attributional style in particular, are related to the genesis of depression in epilepsy. Because they are known to be related to depression in the general population, and because specific techniques for intervention and prevention are available, greater consideration of learned helplessness and attributional style in the genesis of depression in epilepsy may be worthwhile.     

Logitlinear models for the prediction of splice sites in plant pre-mRNA sequences

Pre-mRNA splicing in plants, while generally similar to the processes in vertebrates and yeast, is thought to involve plant specific cis-acting elements. Both monocot and dicot introns are typically strongly enriched in U nucleotides, and AU- or U-rich segments are thought to be involved in intron recognition, splice site selection, and splicing efficiency. We have applied logitlinear models to find optimal combinations of splice site variables for the purpose of separating true splice sites from a large excess of potential sites. It is shown that plant splice site prediction from sequence inspection is greatly improved when compositional contrast between exons and introns is considered in addition to degree of matching to the splice site consensus (signal quality). The best model involves subclassification of splice sites according to the identity of the base immediately upstream of the GU and AG signals and gives substantial performance gains compared with conventional profile methods.     

Modification of carbon nanostructures by high energy ball-milling under argon and hydrogen atmosphere

High energy ball-milling of graphite leads to nanocrystalline structures of carbon. The structures are characterised by small crystalline particles embedded in an amorphous matrix causing a high specific surface area. To investigate and quantify these nanostructures X-ray powder diffraction, high resolution transmission electron microscopy and specific surface area measurements were used. By changing the atmosphere in milling vials from argon to hydrogen the generation of the graphitic nanostructures can be decelerated. Thereby, it is possible to modify the structures in a definite way and to receive higher specific surface areas for longer milling times. Furthermore, during milling under hydrogen atmosphere the broken carbon bonds are saturated by hydrogen. In this way, it is possible to stabilise the produced nanostructures and to prevent agglomeration.     

A NEW CFAR DETECTOR WITH GREATEST OPTION

This paper presents a new CFAR detector based on Ordered Statistics (OS) and Cell-Averaging (CA) forming local estimates, and using Greatest-Of selection (GO) to form clutter power level estimate Z in test cell(OSCAGO). Under the Swerling II assumption, the analytic expressions of Pfa,Pd and ADT of this detector are derived, its detection performance in homogeneous background and in strong interfering targets environment are analyzed and compared it with OS, GOSGO detectors. The results show that the detection performance of OSCAGO in homogeneous background and in multiple-target situations are obviously better than those of OS and GOSGO. When the number of interfering targets is equal to certain value, the CFAR loss of OSCAGO is about 3dB less than that of GOSGO.