Structural analysis, clay mineralogy and K-Ar dating of fault gouges from Centovalli Line (Central Alps) for reconstruction of their recent activity

Between the cities of Domodossola and Locarno, the complex ``Centovalli Line'' tectonic zone of the Central Alps outlines deformation phases over a long period of time (probably starting similar to 30 Ma ago) and under variable P-T conditions. The last deformation phases developed gouge-bearing faults with a general E-W trend that crosscuts the roots of the Alpine Canavese zone and the Finero ultramafic body. Kinematic indicators show that the general motion was mainly dextral associated with back thrusting towards the S. The <2 mu m clay fractions of fault gouges from Centovalli Line consist mainly of illite, smectite and chlorite with varied illite-smectite, chlorite-smectite and chlorite-serpentine mixed-layers. Constrained with the illite crystallinity index, the thermal conditions induced by the tectonic activity show a gradual trend from anchizonal to diagenetic conditions. The <2 and <0.2 mu M clay fractions, and hydrothermal K-feldspar separates all provide K-Ar ages between 14.2 +/- 2.9 Ma and roughly 0 Ma, with major episodes at about 12,8, 6 and close to 0 Ma These ages set the recurrent tectonic activity and the associated fluid circulations between Upper Miocene and Recent. On the basis of the K-Ar ages and with a thermal gradient of 25-30 degrees C/km, the studied fault zones were located at a depth of 4-7 km. If they were active until now as observed in field, the exhumation was approximately 2.5-3.0 km for the last 12 Ma with a mean velocity of 0.4 mm/y. Comparison with available models on the recent Alpine evolution shows that the tectonic activity in the area relates to a continuum of the back-thrusting movements of the Canavese Line, and/or to several late-extensional phases of the Rhone-Simplon line. The Centovalli-Val Vigezzo zone therefore represents a major tectonic zone of the Central-Western Alps resulting from different interacting tectonic events. (C) 2011 Elsevier B.V. All rights reserved.

Bayesian Networks and the Value of the Evidence for the Forensic Two-Trace Transfer Problem

Forensic scientists face increasingly complex inference problems for evaluating likelihood ratios (LRs) for an appropriate pair of propositions. Up to now, scientists and statisticians have derived LR formulae using an algebraic approach. However, this approach reaches its limits when addressing cases with an increasing number of variables and dependence relationships between these variables. In this study, we suggest using a graphical approach, based on the construction of Bayesian networks (BNs). We first construct a BN that captures the problem, and then deduce the expression for calculating the LR from this model to compare it with existing LR formulae. We illustrate this idea by applying it to the evaluation of an activity level LR in the context of the two-trace transfer problem. Our approach allows us to relax assumptions made in previous LR developments, produce a new LR formula for the two-trace transfer problem and generalize this scenario to n traces.

Tibial tunnel placement in posterior cruciate ligament reconstruction: a systematic review.

PURPOSE: Reconstruction of the posterior cruciate ligament (PCL) yields less satisfying results than anterior cruciate ligament reconstruction with respect to laxity control. Accurate tibial tunnel placement is crucial for successful PCL reconstruction using arthroscopic tibial tunnel techniques. A discrepancy between anatomical studies of the tibial PCL insertion site and surgical recommendations for tibial tunnel placement remains. The objective of this study was to identify the optimal placement of the tibial tunnel in PCL reconstruction based on clinical studies. METHODS: In a systematic review of the literature, MEDLINE, EMBASE, Cochrane Review, and Cochrane Central Register of Controlled Trials were screened for articles about PCL reconstruction from January 1990 to September 2011. Clinical trials comparing at least two PCL reconstruction techniques were extracted and independently analysed by each author. Only studies comparing different tibial tunnel placements in the retrospinal area were included. RESULTS: This systematic review found no comparative clinical trial for tibial tunnel placement in PCL reconstruction. Several anatomical, radiological, and biomechanical studies have described the tibial insertion sites of the native PCL and have led to recommendations for placement of the tibial tunnel outlet in the retrospinal area. However, surgical recommendations and the results of morphological studies are often contradictory. CONCLUSIONS: Reliable anatomical landmarks for tunnel placement are lacking. Future randomized controlled trials could compare precisely defined tibial tunnel placements in PCL reconstruction, which would require an established mapping of the retrospinal area of the tibial plateau with defined anatomical and radiological landmarks.

Stage fright: its experience as a problem and coping with it.

PURPOSE AND METHOD: This questionnaire survey of 190 university music students assessed negative feelings of music performance anxiety (MPA) before performing, the experience of stage fright as a problem, and how closely they are associated with each other. The study further investigated whether the experience of stage fright as a problem and negative feelings of MPA predict the coping behavior of the music students. Rarely addressed coping issues were assessed, i.e., self-perceived effectiveness of different coping strategies, knowledge of possible risks and acceptance of substance-based coping strategies, and need for more support.RESULTS: The results show that one-third of the students experienced stage fright as a problem and that this was only moderately correlated with negative feelings of MPA. The experience of stage fright as a problem significantly predicted the frequency of use and the acceptance of medication as a coping strategy. Breathing exercises and self-control techniques were rated as effective as medication. Finally, students expressed a strong need to receive more support (65%) and more information (84%) concerning stage fright.CONCLUSION: Stage fright was experienced as a problem and perceived as having negative career consequences by a considerable percentage of the surveyed students. In addition to a desire for more help and support, the students expressed an openness and willingness to seriously discuss and address the topic of stage fright. This provides a necessary and promising basis for optimal career preparation and, hence, an opportunity to prevent occupational problems in professional musicians. [Authors]

Bioreporters and biosensors for arsenic detection. Biotechnological solutions for a world-wide pollution problem.

A wide variety of whole cell bioreporter and biosensor assays for arsenic detection has been developed over the past decade. The assays permit flexible detection instrumentation while maintaining excellent method of detection limits in the environmentally relevant range of 10-50 μg arsenite per L and below. New emerging trends focus on genetic rewiring of reporter cells and/or integration into microdevices for more optimal detection. A number of case studies have shown realistic field applicability of bioreporter assays.

Investigation of discrete imaging models and iterative image reconstruction in differential X-ray phase-contrast tomography.

Differential X-ray phase-contrast tomography (DPCT) refers to a class of promising methods for reconstructing the X-ray refractive index distribution of materials that present weak X-ray absorption contrast. The tomographic projection data in DPCT, from which an estimate of the refractive index distribution is reconstructed, correspond to one-dimensional (1D) derivatives of the two-dimensional (2D) Radon transform of the refractive index distribution. There is an important need for the development of iterative image reconstruction methods for DPCT that can yield useful images from few-view projection data, thereby mitigating the long data-acquisition times and large radiation doses associated with use of analytic reconstruction methods. In this work, we analyze the numerical and statistical properties of two classes of discrete imaging models that form the basis for iterative image reconstruction in DPCT. We also investigate the use of one of the models with a modern image reconstruction algorithm for performing few-view image reconstruction of a tissue specimen.

A Monte Carlo approach to the inverse problem of diffuse pollution risk in agricultural catchments

The hydrological and biogeochemical processes that operate in catchments influence the ecological quality of freshwater systems through delivery of fine sediment, nutrients and organic matter. Most models that seek to characterise the delivery of diffuse pollutants from land to water are reductionist. The multitude of processes that are parameterised in such models to ensure generic applicability make them complex and difficult to test on available data. Here, we outline an alternative - data-driven - inverse approach. We apply SCIMAP, a parsimonious risk based model that has an explicit treatment of hydrological connectivity. we take a Bayesian approach to the inverse problem of determining the risk that must be assigned to different land uses in a catchment in order to explain the spatial patterns of measured in-stream nutrient concentrations. We apply the model to identify the key sources of nitrogen (N) and phosphorus (P) diffuse pollution risk in eleven UK catchments covering a range of landscapes. The model results show that: 1) some land use generates a consistently high or low risk of diffuse nutrient pollution; but 2) the risks associated with different land uses vary both between catchments and between nutrients; and 3) that the dominant sources of P and N risk in the catchment are often a function of the spatial configuration of land uses. Taken on a case-by-case basis, this type of inverse approach may be used to help prioritise the focus of interventions to reduce diffuse pollution risk for freshwater ecosystems. (C) 2012 Elsevier B.V. All rights reserved.

Buccal mucosa graft for laryngotracheal reconstruction in severe laryngeal stenosis.

OBJECTIVE: An operative technique is described as a salvage treatment for severe subglottic and supraglottic laryngeal stenosis. In addition to expansion of the laryngeal framework with an anterior cartilage graft, as used in a classical laryngotracheal reconstruction, the scar tissue obliterating the airway lumen is excised and a mucosal graft is placed to reconstruct the inner lining of the airway. The graft is harvested from buccal mucosa. METHODS: The operative technique is outlined. Three cases, 2 paediatric and one adult, with complete or near complete laryngeal stenosis are presented where this operative technique was employed. In all patients several surgeries had been performed previously which were unsuccessful. RESULTS: In all 3 patients a patent airway was achieved with decannulation of the tracheostomy in the 2 paediatric patients. CONCLUSIONS: In patients with severe subglottic or supraglottic airway stenosis where other surgeries have failed, excision of endoluminal scar tissue and placement of a buccal mucosal graft, in addition to conventional laryngotracheal reconstruction, is a promising technique. In revision cases of subglottic stenosis cricotracheal resection might not be an option because of scarring from previous surgeries. This operation is an alternative, which allows an increase in the airway lumen by excising the scar tissue then re-lining the exposed internal lumen. The buccal mucosa reduces granulation formation and re-stenosis.

Reduction of respiratory motion artifacts for free-breathing whole-heart coronary MRA by weighted iterative reconstruction.

PURPOSE: To combine weighted iterative reconstruction with self-navigated free-breathing coronary magnetic resonance angiography for retrospective reduction of respiratory motion artifacts. METHODS: One-dimensional self-navigation was improved for robust respiratory motion detection and the consistency of the acquired data was estimated on the detected motion. Based on the data consistency, the data fidelity term of iterative reconstruction was weighted to reduce the effects of respiratory motion. In vivo experiments were performed in 14 healthy volunteers and the resulting image quality of the proposed method was compared to a navigator-gated reference in terms of acquisition time, vessel length, and sharpness. RESULT: Although the sampling pattern of the proposed method contained 60% more samples with respect to the reference, the scan efficiency was improved from 39.5 ± 10.1% to 55.1 ± 9.1%. The improved self-navigation showed a high correlation to the standard navigator signal and the described weighting efficiently reduced respiratory motion artifacts. Overall, the average image quality of the proposed method was comparable to the navigator-gated reference. CONCLUSION: Self-navigated coronary magnetic resonance angiography was successfully combined with weighted iterative reconstruction to reduce the total acquisition time and efficiently suppress respiratory motion artifacts. The simplicity of the experimental setup and the promising image quality are encouraging toward future clinical evaluation. Magn Reson Med 73:1885-1895, 2015. © 2014 Wiley Periodicals, Inc.