41 research outputs found
A novel semi-fragile forensic watermarking scheme for remote sensing images
Peer-reviewedA semi-fragile watermarking scheme for multiple band images is presented. We propose to embed a mark into remote sensing images applying a tree structured vector quantization approach to the pixel signatures, instead of processing each band separately. The signature of themmultispectral or hyperspectral image is used to embed the mark in it order to detect any significant modification of the original image. The image is segmented into threedimensional blocks and a tree structured vector quantizer is built for each block. These trees are manipulated using an iterative algorithm until the resulting block satisfies a required criterion which establishes the embedded mark. The method is shown to be able to preserve the mark under lossy compression (above a given threshold) but, at the same time, it detects possibly forged blocks and their position in the whole image.Se presenta un esquema de marcas de agua semi-frágiles para múltiples imágenes de banda. Proponemos incorporar una marca en imágenes de detección remota, aplicando un enfoque de cuantización del vector de árbol estructurado con las definiciones de píxel, en lugar de procesar cada banda por separado. La firma de la imagen hiperespectral se utiliza para insertar la marca en el mismo orden para detectar cualquier modificación significativa de la imagen original. La imagen es segmentada en bloques tridimensionales y un cuantificador de vector de estructura de árbol se construye para cada bloque. Estos árboles son manipulados utilizando un algoritmo iteractivo hasta que el bloque resultante satisface un criterio necesario que establece la marca incrustada. El método se muestra para poder preservar la marca bajo compresión con pérdida (por encima de un umbral establecido) pero, al mismo tiempo, detecta posiblemente bloques forjados y su posición en la imagen entera.Es presenta un esquema de marques d'aigua semi-fràgils per a múltiples imatges de banda. Proposem incorporar una marca en imatges de detecció remota, aplicant un enfocament de quantització del vector d'arbre estructurat amb les definicions de píxel, en lloc de processar cada banda per separat. La signatura de la imatge hiperespectral s'utilitza per inserir la marca en el mateix ordre per detectar qualsevol modificació significativa de la imatge original. La imatge és segmentada en blocs tridimensionals i un quantificador de vector d'estructura d'arbre es construeix per a cada bloc. Aquests arbres són manipulats utilitzant un algoritme iteractiu fins que el bloc resultant satisfà un criteri necessari que estableix la marca incrustada. El mètode es mostra per poder preservar la marca sota compressió amb pèrdua (per sobre d'un llindar establert) però, al mateix temps, detecta possiblement blocs forjats i la seva posició en la imatge sencera
Real Time Forecasting of Flows and Loads to WWTPs for Enhanced Hydraulic and Biological Capacity during Stormwater Events
Th17 Cells and IL-17 in Protective Immunity to Vaginal Candidiasis
Background: Th17 cells play a major role in coordinating the host defence in oropharyngeal candidiasis. In this study we investigated the involvement of the Th17 response in an animal model of vulvovaginal candidiasis (VVC). Methods: To monitor the course of infection we exploited a new in vivo imaging technique. Results: i) The progression of VVC leads to a strong influx of neutrophils in the vagina soon after the challenge which persisted despite the resolution of infection; ii) IL-17, produced by vaginal cells, particularly CD4 T cells, was detected in the vaginal wash during the infection, reaching a maximum 14 days after the challenge; iii) The amount and kinetics of IL-23 in vaginal fluids were comparable to those in vaginal cells; iv) The inhibition of Th17 differentiation led to significant inhibition of IL-17 production with consequent exacerbation of infection; v) An increased production of bdefensin 2 was manifested in cells of infected mice. This production was strongly reduced when Th17 differentiation was inhibited and was increased by rIL-17 treatment. Conclusions: These results imply that IL-17 and Th17, along with innate antimicrobial factors, have a role in the immune response to vaginal candidiasis
Intellectual enrichment and genetic modifiers of cognition and brain volume in Huntington's disease
An important step towards the development of treatments for cognitive impairment in ageing and neurodegenerative diseases is to identify genetic and environmental modifiers of cognitive function and understand the mechanism by which they exert an effect. In Huntington’s disease, the most common autosomal dominant dementia, a small number of studies have identified intellectual enrichment, i.e. a cognitively stimulating lifestyle and genetic polymorphisms as potential modifiers of cognitive function. The aim of our study was to further investigate the relationship and interaction between genetic factors and intellectual enrichment on cognitive function and brain atrophy in Huntington’s disease. For this purpose, we analysed data from Track-HD, a multi-centre longitudinal study in Huntington’s disease gene carriers and focused on the role of intellectual enrichment (estimated at baseline) and the genes FAN1, MSH3, BDNF, COMT and MAPT in predicting cognitive decline and brain atrophy. We found that carrying the 3a allele in the MSH3 gene had a positive effect on global cognitive function and brain atrophy in multiple cortical regions, such that 3a allele carriers had a slower rate of cognitive decline and atrophy compared with non-carriers, in agreement with its role in somatic instability. No other genetic predictor had a significant effect on cognitive function and the effect of MSH3 was independent of intellectual enrichment. Intellectual enrichment also had a positive effect on cognitive function; participants with higher intellectual enrichment, i.e. those who were better educated, had higher verbal intelligence and performed an occupation that was intellectually engaging, had better cognitive function overall, in agreement with previous studies in Huntington’s disease and other dementias. We also found that intellectual enrichment interacted with the BDNF gene, such that the positive effect of intellectual enrichment was greater in Met66 allele carriers than non-carriers. A similar relationship was also identified for changes in whole brain and caudate volume; the positive effect of intellectual enrichment was greater for Met66 allele carriers, rather than for non-carriers. In summary, our study provides additional evidence for the beneficial role of intellectual enrichment and carrying the 3a allele in MSH3 in cognitive function in Huntington’s disease and their effect on brain structure
Rapidly Rising Transients in the Supernova - Superluminous Supernova Gap
The American Astronomical Society. All rights reserved..We present observations of four rapidly rising (trise ≈ 10 days) transients with peak luminosities between those of supernovae (SNe) and superluminous SNe (Mpeak ap; -20) - one discovered and followed by the Palomar Transient Factory (PTF) and three by the Supernova Legacy Survey. The light curves resemble those of SN 2011kl, recently shown to be associated with an ultra-long-duration gamma-ray burst (GRB), though no GRB was seen to accompany our SNe. The rapid rise to a luminous peak places these events in a unique part of SN phase space, challenging standard SN emission mechanisms. Spectra of the PTF event formally classify it as an SN II due to broad Hα emission, but an unusual absorption feature, which can be interpreted as either high velocity Hα (though deeper than in previously known cases) or Si ii (as seen in SNe Ia), is also observed. We find that existing models of white dwarf detonations, CSM interaction, shock breakout in a wind (or steeper CSM), and magnetar spin down cannot readily explain the observations. We consider the possibility that a "Type 1.5 SN" scenario could be the origin of our events. More detailed models for these kinds of transients and more constraining observations of future such events should help to better determine their nature. © 2016
Istros, Black Sea Coast, Romania A geoarchaeological perspective on the location of the harbour(s)
International audienceIstros, founded during the 7th century BCE, is one of the oldest Greek colonies on the shores of the Black Sea. On the southern margin of the Danube delta, what was an ancient maritime city is now a landlocked archaeological site. Even though archaeological investigations have continued since 1914, the location of the harbour(s) remains unknown. Efforts to find a harbour are hindered by the complex geomorphological evolution of the Danube delta and by the long human occupation history of the site. However, a new perspective is offered by a geoarchaeological approach, combining coring with geophysical and archaeological investigations
Istros, Black Sea Coast, Romania A geoarchaeological perspective on the location of the harbour(s)
International audienceIstros, founded during the 7th century BCE, is one of the oldest Greek colonies on the shores of the Black Sea. On the southern margin of the Danube delta, what was an ancient maritime city is now a landlocked archaeological site. Even though archaeological investigations have continued since 1914, the location of the harbour(s) remains unknown. Efforts to find a harbour are hindered by the complex geomorphological evolution of the Danube delta and by the long human occupation history of the site. However, a new perspective is offered by a geoarchaeological approach, combining coring with geophysical and archaeological investigations
Istros, Black Sea Coast, Romania A geoarchaeological perspective on the location of the harbour(s)
International audienceIstros, founded during the 7th century BCE, is one of the oldest Greek colonies on the shores of the Black Sea. On the southern margin of the Danube delta, what was an ancient maritime city is now a landlocked archaeological site. Even though archaeological investigations have continued since 1914, the location of the harbour(s) remains unknown. Efforts to find a harbour are hindered by the complex geomorphological evolution of the Danube delta and by the long human occupation history of the site. However, a new perspective is offered by a geoarchaeological approach, combining coring with geophysical and archaeological investigations
Freeform reversible embedding of suspended hydrogels for the manufacturing of biomedical applications
Additive Manufacturing (AM) can be applied in different medical applications. Amongst all the AM technologies, DIW (Direct Ink Writing), FDM (Fused Deposition Modelling) and SLS (Selective Laser Sintering) are some of the most popular. Nevertheless, in case of biomedical applications, DIW was identified as the best option since it easily handles hydrogels and silicones, two great materials for biomedical applications. However, these materials present some difficulties in being 3D printed due to their low yield stress values which lead to the 3D printed sample to fall apart. To overcome these problems, the FRESH (Freeform Reversible Embedding of Suspended Hydrogels) technique has been developed and implemented. In this technique, a supporting gel bath is used as the support material, and removed after the material curing process. Additionally, and in particular conditions, this support bath can be reused multiple times, making the technique a cost-effective approach. In the present study, several simple and complex silicone samples were manufactured using FRESH, confirming not only the success of this AM technique for biomedical applications, but also its effectivenessPostprint (published version