Model-based Matching Pursuit - Estimation of Chirp Factors and Scale of Gabor Atoms with Iterative Extension

International audienceBy definition, the Matching Pursuit algorithm with constant (or "flat") Gabor atoms provides a coarse estimate of frequency modulated sinusoids in music and voice signals. Chirped Gabor atoms, closer to the nature of these signals, would fit them in a finer and sparser way. Though a method for the direct analytic estimation of chirped Gabor atoms has been proposed in the past, the present article proposes an alternative method where the chirp factor and scale parameter are estimated through a regression over an iteratively selected chain of small-scale atoms defined by a Short Time Fourier Transform. This new technique suits the Matching Pursuit framework, and is compared with a "flat atoms" version of the algorithm. The influence of various frequency interpolation techniques over the sparsity of the resulting representation is also studied

Reconstructing the hydraulics of the world’s first industrial complex, the second century CE Barbegal watermills, France

The Barbegal watermill complex, a unique cluster of 16 waterwheels in southern France, was the first known attempt in Europe to set up an industrial-scale complex of machines during the culmination of Roman Civilization in the second century CE. Little is known about the state of technological advance in this period, especially in hydraulics and the contemporary diffusion of knowledge. Since the upper part of the Barbegal mill complex has been destroyed and no traces of the wooden machinery survived, the mode of operation of these mills has long remained elusive. Carbonate incrustations that formed on the woodwork of the mills were used to reconstruct its structure and function, revealing a sophisticated hydraulic setup unique in the history of water mills. The lower mills used an elbow shaped flume to bring water onto overshot millwheels. This flume was specially adapted to the small water basins and serial arrangement of the mills on the slope. Carbonate deposits from ancient water systems are therefore a powerful tool in archaeological reconstructions and provide tantalizing insights into the skills of Roman engineers during a period of history that is the direct predecessor of our modern civilization

Recognizing Thousands of Legal Entities through Instance-based Visual Classification

International audienceThis paper considers the problem of recognizing legal en-tities in visual contents in a similar way to named-entity recognizers for text documents. Whereas previous works were restricted to the recognition of a few tens of logotypes, we generalize the problem to the recognition of thousands of legal persons, each being modeled by a rich corporate identity automatically built from web images. We intro-duce a new geometrically-consistent instance-based classifi-cation method that is shown to outperform state-of-the-art techniques on several challenging datasets while being much more scalable. Further experiments performed on an au-tomatic web crawl of 5,824 legal entities demonstrates the scalability of the approach

'Divided they stand, divided they fail': opposition politics in Morocco

The literature on democratization emphasises how authoritarian constraints usually lead genuine opposition parties and movements to form alliances in order to make demands for reform to the authoritarian regime. There is significant empirical evidence to support this theoretical point. While this trend is partly visible in the Middle East and North Africa, such coalitions are usually short-lived and limited to a single issue, never reaching the stage of formal and organic alliances. This article, using the case of Morocco, seeks to explain this puzzle by focusing on ideological and strategic differences that exist between the Islamist and the secular/liberal sectors of civil society, where significant opposition politics occurs. In addition, this article also aims to explain how pro-democracy strategies of the European Union further widen this divide, functioning as a key obstacle to democratic reforms

Tetratricopeptide repeat domain 7A is a nuclear factor that modulates transcription and chromatin structure

A loss-of-function mutation in tetratricopeptide repeat domain 7A (TTC7A) is a recently identified cause of human intestinal and immune disorders. However, clues to related underlying molecular dysfunctions remain elusive. It is now shown based on the study of TTC7A-deficient and wild-type cells that TTC7A is an essential nuclear protein. It binds to chromatin, preferentially at actively transcribed regions. Its depletion results in broad range of epigenomic changes at proximal and distal transcriptional regulatory elements and in altered control of the transcriptional program. Loss of WT_TTC7A induces general decrease in chromatin compaction, unbalanced cellular distribution of histones, higher nucleosome accessibility to nuclease digestion along with genome instability, and reduced cell viability. Our observations characterize for the first time unreported functions for TTC7A in the nucleus that exert a critical role in chromatin organization and gene regulation to safeguard healthy immune and intestinal status.</p

Modelo de um sistema eutrófico: fluxo dos nutrientes e sinecologia das populações planctônicas

Based on the information obtained from the Gulf of Fos, France, we propose herewith a generalized model to characterize the physical, chemical and biological parameters and their interrelationship in the eutrophic coastal system. This system is characterized by having high concentration of suspended materials, especially the mineral fraction (C/N >; 30). Nutrients concentrations are very high, except in diluted basins. The N-NO3/P-P04 ratio is usually low, due to the preferential assimilation of nitrates and the presence of polyphosphates from sewage waters. The concentrations of phaeopigments are always high (more than 50%), due to the mortalities of freshwater originated phytoplankton, the resuspension of dead vegetal materials, and the grazing of zooplankton. We noted in diluted water of eutrophic system the biomass is high, but the diversity is relatived low, among adapted cells with low " energetic charge". Whereas in oceanic water, the biomass is less, the diversity and energetic charge are increasing. This may indicate that phytoplankton communities have to make an effort to grow and duplicate. In comparing zooplankton populations from eutrophic to oligotrophic waters, biochemical diferentiations were observed for a same species, which may due to the difference in salinities and the presence of chemical pollutants

Technical Note: New ground-based FTIR measurements at Ile de La Réunion: observations, error analysis, and comparisons with independent data

Ground-based high spectral resolution Fourier-transform infrared (FTIR) solar absorption spectroscopy is a powerful remote sensing technique to obtain information on the total column abundances and on the vertical distribution of various constituents in the atmosphere. This work presents results from two FTIR measurement campaigns in 2002 and 2004, held at Ile de La Réunion (21° S, 55° E). These campaigns represent the first FTIR observations carried out at a southern (sub)tropical site. They serve the initiation of regular, long-term FTIR monitoring at this site in the near future. To demonstrate the capabilities of the FTIR measurements at this location for tropospheric and stratospheric monitoring, a detailed report is given on the retrieval strategy, information content and corresponding full error budget evaluation for ozone (O3), methane (CH4), nitrous oxide (N2O), carbon monoxide (CO), ethane (C2H6), hydrogen chloride (HCl), hydrogen fluoride (HF) and nitric acid (HNO3) total and partial column retrievals. Moreover, we have made a thorough comparison of the capabilities at sea level altitude (St.-Denis) and at 2200 m a.s.l. (Maïdo). It is proved that the performances of the technique are such that the atmospheric variability can be observed, at both locations and in distinct altitude layers. Comparisons with literature and with correlative data from ozone sonde and satellite (i.e., ACE-FTS, HALOE and MOPITT) measurements are given to confirm the results. Despite the short time series available at present, we have been able to detect the seasonal variation of CO in the biomass burning season, as well as the impact of particular biomass burning events in Africa and Madagascar on the atmospheric composition above Ile de La Réunion. We also show that differential measurements between St.-Denis and Maïdo provide useful information about the concentrations in the boundary layer.Peer reviewe

Alteration of Blood–Brain Barrier Integrity by Retroviral Infection

The blood–brain barrier (BBB), which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1) Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans), both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies

Standards for plant synthetic biology: a common syntax for exchange of DNA parts.

Inventors in the field of mechanical and electronic engineering can access multitudes of components and, thanks to standardization, parts from different manufacturers can be used in combination with each other. The introduction of BioBrick standards for the assembly of characterized DNA sequences was a landmark in microbial engineering, shaping the field of synthetic biology. Here, we describe a standard for Type IIS restriction endonuclease-mediated assembly, defining a common syntax of 12 fusion sites to enable the facile assembly of eukaryotic transcriptional units. This standard has been developed and agreed by representatives and leaders of the international plant science and synthetic biology communities, including inventors, developers and adopters of Type IIS cloning methods. Our vision is of an extensive catalogue of standardized, characterized DNA parts that will accelerate plant bioengineering.Biotechnological and Biological Sciences Research Council (BBSRC). Grant Numbers: BB/K005952/1, BB/L02182X/1 Synthetic Biology Research Centre ‘OpenPlant’ award. Grant Number: BB/L014130/1 Spanish MINECO. Grant Number: BIO2013‐42193‐R Engineering Nitrogen Symbiosis for Africa (ENSA) The Bill & Melinda Gates Foundation US Department of Energy, Office of Biological and Environmental. Grant Number: DE‐AC02‐05CH1123 COST Action. Grant Number: FA100