Signal Models for Changes in Polarimetric SAR Data

Synthetic aperture radar (SAR) polarimetry can improve change detection in terms of detection capabilities. In this work, we are proposing to extend the idea of target decomposition to changes affecting partial targets. This will allow the separation of polarimetric-dependent changes, providing extra information that can be used to better understand the processes affecting the targets. Three models for changes are proposed and compared. The methodologies are based on Lagrangian optimizations of distinct operators built using quadratic forms for a power ratio and a power difference. The optimizations can be accomplished by diagonalizations of specific matrices derived from polarimetric covariance matrices. These are, therefore, spectral decompositions of an appropriate matrix which we define as change matrix. The theoretical validity of the models is assessed using Monte Carlo simulations. Additionally, we perform real data validation exploiting L-band quad-polarimetric data from the E-SAR (DLR) SARTOM 2006 campaign and ALOS PALSAR (JAXA) acquisitions in Morecombe Bay (U.K.). We observed that the two algorithms based on power difference allow to decompose the change into the minimal set of scattering mechanisms (SMs) that have been added or removed from the scene. The two algorithms differ on the initial assumption on the change. On the other hand, the ratio operator provides a better detection performance although the eigenvalues do not correspond to meaningful SMs. A combination of the three methodologies can, therefore, improve detection and classification of changes

Bears and Humans, a Neanderthal tale. Reconstructing uncommon behaviors from zooarchaeological evidence in Southern Europe

Cave bear (Ursus spelaeus), brown bear (Ursus arctos), and Neanderthals were potential competitors for environmental resources (shelters and food) in Europe. In order to reinforce this view and contribute to the ongoing debate on late Neanderthal behavior, we present evidence from zooarchaeological and taphonomic analyses of bear bone remains discovered at Rio Secco Cave and Fumane Cave in northeast Italy, an extended geographic area north of the Adriatic Sea. The remains from both caves come from layers dated to 49-42 ky cal. BP, and suggest close interactions between humans and bears, with data not only limited to the association of Mousterian lithic artifacts with numerous bear remains, but also the detection of clearly preserved traces of human modification such as cut and percussion marks, which enable a reconstruction of the main steps of fur recovery and the butchering process. Examples of Neanderthal bear exploitation are extremely sporadic in Europe, and Grotta Rio Secco and Grotta Fumane can be considered rare cases of remain accumulations generated by the human predation of bears of varied age classes during or near the end of hibernation. All of this evidence suggests that bears had a strategic role in the nomadic economy of Neanderthal hunting groups

Archaeometric analysis of painted tombstones (IV century BC) from Paestum (Italy)

50 graves, painted by fresco technique, have been analyzed by micro-Raman Spectroscopy and X-Ray Fluorescence in order to identify the artists’ palettes and attempt to differentiate various workshops. Before sampling, points of interest were selected by a preliminary in situ XRF analysis. Then, samples were collected and analyzed in laboratory by micro-Raman Spectroscopy. We sampled from Green, Blue, Red, Yellow and Black areas, from every grave, and created a database where we put together analytical and historical data. Red and Yellow are obtained by Hematite and Goethite, respectively; Blue is always Egyptian Blue; Black contains Carbon or Magnetite, or a mix of them. Interesting data came from Green areas. We found 2 mixtures: Egyptian Blue and Yellow Ochre, or Yellow Ochre and Carbon. This peculiarity could be useful in the future for the discrimination of the different workshops

Intertidal Mediterranean coralline algae habitat is expecting a shift towards a reduced growth and a simplified associated fauna under climate change

Coralline algae represent the most important bioconstructors in the Mediterranean Sea and are currently impaired by the effects of climate change (CC), particularly by global warming and ocean acidification (OA). We studied the effects of these two drivers on Ellisolandia elongate, an intertidal coralline algae that is known to host a rich biodiversity of associated fauna. We cultured turfs of E. elongate in experimental conditions of increased temperature and OA (using the values of the IPCC scenario RCP- 8.5 expected for 2100: actual mean temperature +3 degrees C and pH = 7.78), and estimated alteration of algal linear growth and community structure, focusing especially on peracarid crustaceans and annelids. Our findings revealed a decrease in linear growth, yet with no significant changes on structural integrity, and a simplification of associated community, in particular for peracarids. Our study contributes to understand community-level response to CC drivers, highlighting the vulnerability of the fauna associated to an important Mediterranean marine habitat

Single-Look SAR Tomography of Urban Areas

Synthetic aperture radar (SAR) tomography (TomoSAR) is a multibaseline interferometric technique that estimates the power spectrum pattern (PSP) along the perpendicular to the line-ofsight (PLOS) direction. TomoSAR achieves the separation of individual scatterers in layover areas, allowing for the 3D representation of urban zones. These scenes are typically characterized by buildings of different heights, with layover between the facades of the higher structures, the rooftop of the smaller edifices and the ground surface. Multilooking, as required by most spectral estimation techniques, reduces the azimuth-range spatial resolution, since it is accomplished through the averaging of adjacent values, e.g., via Boxcar filtering. Consequently, with the aim of avoiding the spatial mixture of sources due to multilooking, this article proposes a novel methodology to perform single-look TomoSAR over urban areas. First, a robust version of Capon is applied to focus the TomoSAR data, being robust against the rank-deficiencies of the data covariance matrices. Afterward, the recovered PSP is refined using statistical regularization, attaining resolution enhancement, suppression of artifacts and reduction of the ambiguity levels. The capabilities of the proposed methodology are demonstrated by means of strip-map airborne data of the Jet Propulsion Laboratory (JPL) and the National Aeronautics and Space Administration (NASA), acquired by the uninhabited aerial vehicle SAR (UAVSAR) system over the urban area of Munich, Germany in 2015. Making use of multipolarization data [horizontal/horizontal (HH), horizontal/vertical (HV) and vertical/vertical (VV)], a comparative analysis against popular focusing techniques for urban monitoring (i.e., matched filtering, Capon and compressive sensing (CS)) is addressed

Differential Responses of Colorectal Cancer Cell Lines to Enterococcus faecalis' Strains Isolated from Healthy Donors and Colorectal Cancer Patients

The metabolites produced by the host’s gut microbiota have an important role in the maintenance of intestinal homeostasis, but can also act as toxins and induce DNA damage in colorectal epithelial cells increasing the colorectal cancer (CRC) chance. In this scenario, the impact of some of the components of the natural human gastrointestinal microbiota, such as Enterococcus faecalis (E. faecalis), at the onset of CRC progression remains controversial. Since under dysbiotic conditions it could turn into a pathogen, the aim of this study was to compare the effect of E. faecalis’ strains (isolated from CRC patients and healthy subjects’ stools) on the proliferation of different colorectal cells lines. First, we isolated and genotyping characterized the Enterococcus faecalis’ strains. Then, we analyzed the proliferation index (by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay) of three tumor and one normal intestinal cell lines, previously exposed to E. faecalis strains pre-cultured medium. Stool samples of CRC patients demonstrated a reduced frequency of E. faecalis compared to healthy subjects. In addition, the secreted metabolites of E. faecalis’ strains, isolated from healthy donors, decreased the human ileocecal adenocarcinoma cell line HCT-8 and human colon carcinoma cell line HCT-116 cell proliferation without effects on human colorectal adenocarcinoma cell line SW620 and on normal human diploid cell line CLR-1790. Notably, the metabolites of the strains isolated from CRC patients did not influence the cell growth of CRC cell lines. Our results demonstrated a new point of view in the investigation of E. faecalis’ role in CRC development, which raises awareness of the importance of not only associating the presence/absence of a unique microorganism, but also in defining the specific characteristics of the different investigated strains