Stability estimates for an inverse scattering problem at high frequencies

We consider an inverse scattering problem and its near-field approximation at high frequencies. We first prove, for both problems, Lipschitz stability results for determining the low-frequency component of the potential. Then we show that, in the case of a radial potential supported sufficiently near the boundary, infinite resolution can be achieved from measurements of the near-field operator in the monotone case

Evaluation of an alternative spectroscopic approach for aflatoxin analysis: Comparative analysis of food and feed samples with UPLC-MS/MS

Increasing research has highlighted the effects of changing climates on the occurrence and prevalence of toxigenic Aspergillus species producing aflatoxins. There is concern of the toxicological effects to human health and animal productivity following acute and chronic exposure that may affect the future ability to provide safe and sufficient food globally. Considerable research has focused on the detection of these toxins, based on the physicochemical and biochemical properties of the aflatoxin compounds, in agricultural products for human and animal consumption. As improvements in food security continue more regulations for acceptable levels of aflatoxins have arisen globally; the most stringent in Europe. These regulations are important for developing countries as aflatoxin occurrence is high significantly effecting international trade and the economy. In developed countries analytical approaches have become highly sophisticated, capable of attaining results with high precision and accuracy, suitable for regulatory laboratories. Regrettably, many countries that are affected by aflatoxin contamination do not have resources for high tech HPLC and MS instrumentation and require more affordable, yet robust equally accurate alternatives that may be used by producers, processors and traders in emerging economies. It is especially important that those companies wishing to exploit the opportunities offered by lucrative but highly regulated markets in the developed world, have access to analytical methods that will ensure that their exports meet their customers quality and safety requirements. This work evaluates the ToxiMet system as an alternative approach to UPLC–MS/MS for the detection and determination of aflatoxins relative to current European regulatory standards. Four commodities: rice grain, maize cracked and flour, peanut paste and dried distillers grains were analysed for natural aflatoxin contamination. For B1 and total aflatoxins determination the qualitative correlation, above or below the regulatory limit, was good for all commodities with the exception of the dried distillers grain samples for B1 for which no calibration existed. For B1 the quantitative R2 correlations were 0.92, 0.92, 0.88 (<250 μg/kg) and 0.7 for rice, maize, peanuts and dried distillers grain samples respectively whereas for total aflatoxins the quantitative correlation was 0.92, 0.94, 0.88 and 0.91. The ToxiMet system could be used as an alternative for aflatoxin analysis for current legislation but some consideration should be given to aflatoxin M1 regulatory levels for these commodities considering the high levels detected in this study especially for maize and peanuts. (Résumé d'auteur

Negative regulation of EB1 turnover at microtubule plus ends by interaction with microtubule-associated protein ATIP3

International audienceThe regulation of microtubule dynamics is critical to ensure essential cell functions. End binding protein 1 (EB1) is a master regulator of microtubule dynamics that autonomously binds an extended GTP/GDP-Pi structure at growing microtubule ends and recruits regulatory proteins at this location. However, negative regulation of EB1 association with growing microtubule ends remains poorly understood. We show here that microtubule-associated tumor suppressor ATIP3 interacts with EB1 through direct binding of a non-canonical proline-rich motif. Results indicate that ATIP3 does not localize at growing microtubule ends and that in situ ATIP3-EB1 molecular complexes are mostly detected in the cytosol. We present evidence that a minimal EB1-interacting sequence of ATIP3 is both necessary and sufficient to prevent EB1 accumulation at growing microtubule ends in living cells and that EB1-interaction is involved in reducing cell polarity. By fluorescence recovery of EB1-GFP after photobleaching, we show that ATIP3 silencing accelerates EB1 turnover at microtubule ends with no modification of EB1 diffusion in the cytosol. We propose a novel mechanism by which ATIP3-EB1 interaction indirectly reduces the kinetics of EB1 exchange on its recognition site, thereby accounting for negative regulation of microtubule dynamic instability. Our findings provide a unique example of decreased EB1 turnover at growing microtubule ends by cytosolic interaction with a tumor suppressor. INTRODUCTION Microtubules (MTs) are polarized structures that continuously switch between periods of polymerization and depolymerization at their growing (plus) ends. This process, termed MT dynamic instability, allows rapid reorganization of the MT cytoskeleton during essential cell functions such as cell polarity and migration, mitosi

Model evaluation and ensemble modelling of surface-level ozone in Europe and North America in the context of AQMEII

More than ten state-of-the-art regional air quality models have been applied as part of the Air Quality Model Evaluation International Initiative (AQMEII). These models were run by twenty independent groups in Europe and North America. Standardised modelling outputs over a full year (2006) from each group have been shared on the web-distributed ENSEMBLE system, which allows for statistical and ensemble analyses to be performed by each group. The estimated ground-level ozone mixing ratios from the models are collectively examined in an ensemble fashion and evaluated against a large set of observations from both continents. The scale of the exercise is unprecedented and offers a unique opportunity to investigate methodologies for generating skilful ensembles of regional air quality models outputs. Despite the remarkable progress of ensemble air quality modelling over the past decade, there are still outstanding questions regarding this technique. Among them, what is the best and most beneficial way to build an ensemble of members? And how should the optimum size of the ensemble be determined in order to capture data variability as well as keeping the error low? These questions are addressed here by looking at optimal ensemble size and quality of the members. The analysis carried out is based on systematic minimization of the model error and is important for performing diagnostic/probabilistic model evaluation. It is shown that the most commonly used multi-model approach, namely the average over all available members, can be outperformed by subsets of members optimally selected in terms of bias, error, and correlation. More importantly, this result does not strictly depend on the skill of the individual members, but may require the inclusion of low-ranking skill-score members. A clustering methodology is applied to discern among members and to build a skilful ensemble based on model association and data clustering, which makes no use of priori knowledge of model skill. Results show that, while the methodology needs further refinement, by optimally selecting the cluster distance and association criteria, this approach can be useful for model applications beyond those strictly related to model evaluation, such as air quality forecasting. (C) 2012 Elsevier Ltd. All rights reserved.Peer reviewe

Neilan, “Sive” Sadhbh

Sadhbh “Sive” Neilan is an 83 year old woman who identifies as a lesbian and a feminist. Neilan has been an active political figure, activist, and entrepreneur in the Southern Maine area since immigrating here in 1978. Neilan served as President of MLGPA (Maine lesbian gay political alliance) for a short period of time and ran as a democrat for the State Senate in the early 1990s. Neilan also owned and ran New Leaf Books, a feminist alternative bookstore in Rockport, Maine. In this interview, Neilan discusses the intersectional nature of her queer identity and feminist identity. Citation Please cite as: Querying the Past: LGBTQ Maine Oral History Project Collection, Lesbian, Gay, Bisexual, Transgender, and Queer+ Collection, Jean Byers Sampson Center for Diversity in Maine, University of Southern Maine Libraries.https://digitalcommons.usm.maine.edu/querying_ohproject/1138/thumbnail.jp

Scenario planning with mobile payments in emerging markets

CEM

Tempo de opção

Background & Aims: There is little information regarding the extent to which difficult to cure patients with advanced liver fibrosis, due to hepatitis C virus genotype-1 (HCV-1) can successfully and safely be treated with triple therapy with telaprevir (TVR), pegylated interferon alpha (P) and ribavirin (R). In the TVR early access program HEP3002 we aimed to explore treatment safety and efficacy, and identify predictors of sustained virological response at week 24 (SVR24). Methods: 1078 patients with bridging fibrosis (n = 552) or cirrhosis (n = 526) diagnosed by either liver biopsy or non-invasive markers, with compensated bone marrow (neutrophils >1500/ mm3, Hb >12/13 g/dl) and liver function (Albumin >3.3 g/dl, Platelets >90,000/ml) received TVR PR for 12 weeks, followed by a PR tail according to label. Results: Overall, 614 (57%) achieved SVR24 by intention-to-treat analysis. The SVR24 rate was 68% in 221 treatment naïve patients (62.8% F4), 72% in 356 prior relapsers (64.4% F4), 55% in 139 partial responders (53.2% F4), and 34% in 294 null responders (28.6% F4). The SVR24 rate to response-guided therapy (24 weeks treatment duration if undetectable viremia at weeks 4 and 12) was 84% in 222 naïve/relapser F3 patients. Independent predictors of response were: (A) F3 (odds ratio (OR) = 1.51, 95% CI 1.31- 2.00, p = 0.005), (B) subtype 1b (OR = 1.63, 95% CI 1.18-2.24, p = 0.0029), (C) alpha-fetoprotein <10 ng/ml (OR = 2.50, 95% CI 1.87-3.36, p <0.0001) and (D) any prior response other than null (OR = 3.29, 95% CI 2.40-4.52, p <0.0001). SVR24 rose for patients who had more of these predictive factors: 6/32 (19%) for none, 38/139 (27%) for 1, 129/260 (50%) for 2, 202/329 (61%) for 3, and 194/235 (83%) for 4 factors. Grade 2-4 treatment-related adverse events (AE) were experienced by 719 (67%) patients; 169 (16%) discontinued therapy for AE and 7 (0.6%) died during the PR tail. Conclusions: Naïve and experienced patients with advanced fibrosis or cirrhosis due to HCV-1 who have compensated bone marrow and liver function, can effectively and safely be treated by TVR triple therapy. Baseline predictors of outcome have been identified to optimize pre-treatment counselling.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Final results of the telaprevir access program: Fibroscan values predict safety and efficacy in hepatitis c patients with advanced fibrosis or cirrhosis

Background: Liver stiffness determined by transient elastography is correlated with hepatic fibrosis stage and has high accuracy for detecting severe fibrosis and cirrhosis in chronic hepatitis C patients. We evaluated the clinical value of baseline FibroScan values for the prediction of safety and efficacy of telaprevir-based therapy in patients with advanced fibrosis and cirrhosis in the telaprevir Early Access Program HEP3002. Methods: 1,772 patients with HCV-1 and bridging fibrosis or cirrhosis were treated with telaprevir plus pegylated interferon-α and ribavirin (PR) for 12 weeks followed by PR alone, the total treatment duration depending on virological response and previous response type. Liver fibrosis stage was determined either by liver biopsy or by non-invasive markers. 1,282 patients (72%) had disease stage assessed by FibroScan; among those 46% were classified as Metavir F3 at baseline and 54% as F4. Results: Overall, 1,139 patients (64%) achieved a sustained virological response (SVR) by intentionto- treat analysis. Baseline FibroScan values were tested for association with SVR and the occurrence of adverse events. By univariate analysis, higher baseline FibroScan values were predictive of lower sustained virological response rates and treatment-related anemia. By multivariate analysis, FibroScan was no longer statistically significant as an independent predictor, but higher FibroScan values were correlated with the occurrence of infections and serious adverse events. Conclusions: FibroScan has a limited utility as a predictor of safety and efficacy in patients treated with telaprevir-based triple therapy. Nevertheless it can be used in association with other clinical and biological parameters to help determine patients who will benefit from the triple regiments. © 2015 Lepida et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Petrophysical zoning elements of Chertovo Koryto gold-ore deposit (Patom Upland, Eastern Siberia)

The paper considers magnetic susceptibility (chi) and electrode potentials (EP) of rocks in the Chertovo Koryto deposit. Carbon-bearing substance is found in all the studied samples, but in some cases, this substance supplies EP (-150 ± -400 mV). In these samples [chi] rarely exceeds 40·10{-5} SI units, while, in other samples [chi] is 8-10 (up to 30) times higher. Less intensive EP (-20 ± -240 mV) is furnished due to the sulfides in this deposit. Rocks with polarized carbon-bearing substance do not contain magnetic pyrrhotine and are negative linear EP anomalies. Rocks in which carbon-bearing substance is associated with pyrrhotine are revealed as magnetic anomalies. The adjacent rocks determine petrophysical zoning of the Chertovo Koryto deposit. The combination of negative linear EP anomalies and magnetic anomalies is a potential indicator and can define the multi-stage formation of the deposit itself