Wavelet denoising based on local regularity information

International audienceWe present a denoising method that is well fitted to the processing of extremely irregular signals such as (multi)fractal ones. Such signals are often encountered in practice, e.g., in biomedical applications. The basic idea is to estimate the regularity of the original data from the observed noisy ones using the large scale information, and then to extrapolate this information to the small scales. We present theoretical results describing the precise properties of the method. Numerical experiments show that this denoising scheme indeed performs well on irregular signals

Rock glaciers throughout the French Alps accelerated and destabilised since 1990 as air temperatures increased

Rock glaciers—ice-rich creeping landforms typical of permafrost mountain ranges—can develop an anomalous landslide-like behaviour called destabilisation. This behaviour is characterised by failure mechanisms (including cracks and crevasses) and increases in displacement rates by one to two orders of magnitude. Existing studies of this phenomenon have been limited to a small number of landforms and short time spans. Here, we systematically investigate the evolution of rock glacier kinematics over the past seven decades for the entire French Alps by combining observations of landform features indicative of the onset of destabilisation with data on displacements rates using aerial orthoimagery. We show that rock glacier velocities have significantly increased since the 1990s, concurrent with the development of destabilisation in 18 landforms that represent 5% of the 337 active rock glaciers. This pattern of activity correlates with rising air temperatures in the region, which suggests that a warming climate may play a role in this process

Application of fractal tools for the classification of microscopical images of milk fat

International audienceNumerous butter features, such as spreadability, depend on the crystallization, which is observable on microscopical images of milk fat. As microstructures often reveal rough or irregular aspect, fractal tools appear to be particularly adapted to their study. In this paper, fractal techniques quantifying the texture of the image are applied to separate type, plant and day of ripening of different butters. The images are taken from butters produced in industrial conditions. The influence of the crystallization on the fractal parameters has been observed. Fractal quantifiers have demonstrated promising correlations with the day of ripening of the butter. Moreover, they have also shown to be efficient in separating different kinds of butters

Application d'outils fractals pour la classification d'images microscopiques de matières grasses laitières

- De nombreuses caractéristiques du beurre, comme sa "tartinabilité", dépendent de la cristallisation, qui est observable sur les images microscopiques de matière grasse laitière. Comme la microstructure revêt souvent un aspect irrégulier, les outils fractals semblent particulièrement adaptés à l'étude de ces images. Dans ce papier, des techniques fractales reflétant la texture de l'image sont appliquées pour séparer le type, le site de production et le jour de maturation de différents beurres. Les images sont obtenues à partir de beurres produits dans des conditions industrielles. L'influence de la cristallisation a été observée sur ces paramètres fractals. Des corrélations prometteuses avec le jour de maturation ont été démontrées. De plus, il a été possible de séparer différents types de beurre et différents sites de production

Application of fractal tools for the classification of microscopical images of milk fat

International audienceNumerous butter features, such as spreadability, depend on the crystallization, which is observable on microscopical images of milk fat. As microstructures often reveal rough or irregular aspect, fractal tools appear to be particularly adapted to their study. In this paper, fractal techniques quantifying the texture of the image are applied to separate type, plant and day of ripening of different butters. The images are taken from butters produced in industrial conditions. The influence of the crystallization on the fractal parameters has been observed. Fractal quantifiers have demonstrated promising correlations with the day of ripening of the butter. Moreover, they have also shown to be efficient in separating different kinds of butters

Mapping the <i>Shh</i> long-range regulatory domain

Coordinated gene expression controlled by long-distance enhancers is orchestrated by DNA regulatory sequences involving transcription factors and layers of control mechanisms. The Shh gene and well-established regulators are an example of genomic composition in which enhancers reside in a large desert extending into neighbouring genes to control the spatiotemporal pattern of expression. Exploiting the local hopping activity of the Sleeping Beauty transposon, the lacZ reporter gene was dispersed throughout the Shh region to systematically map the genomic features responsible for expression activity. We found that enhancer activities are retained inside a genomic region that corresponds to the topological associated domain (TAD) defined by Hi-C. This domain of approximately 900 kb is in an open conformation over its length and is generally susceptible to all Shh enhancers. Similar to the distal enhancers, an enhancer residing within the Shh second intron activates the reporter gene located at distances of hundreds of kilobases away, suggesting that both proximal and distal enhancers have the capacity to survey the Shh topological domain to recognise potential promoters. The widely expressed Rnf32 gene lying within the Shh domain evades enhancer activities by a process that may be common among other housekeeping genes that reside in large regulatory domains. Finally, the boundaries of the Shh TAD do not represent the absolute expression limits of enhancer activity, as expression activity is lost stepwise at a number of genomic positions at the verges of these domains

csal1 Is Controlled by a Combination of FGF and Wnt Signals in Developing Limb Buds

While some of the signaling molecules that govern establishment of the limb axis have been characterized, little is known about the downstream effector genes that interpret these signals. In Drosophila, the spalt gene is involved in cell fate determination and pattern formation in different tissues. We have cloned a chick homologue of Drosophila spalt, which we have termed csal1, and this study focuses on the regulation of csal1 expression in the limb bud. csal1 is expressed in limb buds from HH 17 to 26, in both the apical ectodermal ridge and the distal mesenchyme. Signals from the apical ridge are essential for csal1 expression, while the dorsal ectoderm is required for csal1 expression at a distance from the ridge. Our data indicate that both FGF and Wnt signals are required for the regulation of csal1 expression in the limb. Mutations in the human homologue of csal1, termed Hsal1/SALL1, result in a condition known as Townes–Brocks syndrome (TBS), which is characterized by preaxial polydactyly. The developmental expression of csal1 together with the digit phenotype in TBS patients suggests that csal1 may play a role in some aspects of distal patterning

Vitamin D3 regulates cell viability in gastric cancer and cholangiocarcinoma

A low serum level of vitamin D has been associated with an increased incidence of gastrointestinal tract cancers. However, the effects of vitamin D3 have not been investigated in gastric cancer and cholangiocarcinoma. In the present study, we found that vitamin D3 treatment significantly suppressed the viability of gastric cancer and cholangiocarcinoma cells. Moreover, vitamin D3 had a synergistic effect with other anti-cancer drugs, such as paclitaxel, adriamycin, and vinblastine, for suppressing cell viability. To determine the underlying mechanism involved in the regulation of viability by vitamin D3, we examined the effects of vitamin D3 on expression of hedgehog signaling target genes, which has been associated with gastric cancer and cholangiocarcinoma. Vitamin D3 treatment decreased the level of mRNA expression of patched1, Gli1, cyclin D1, and Bcl2, suggesting the possibility that vitamin D3 may act through regulation of hedgehog signaling. From the above results, we conclude that vitamin D3 regulates cell viability in gastric cancer and cholangiocarcinoma