29 research outputs found
Hyperspectral monitoring of green roof vegetation health state in sub-mediterranean climate: preliminary results
In urban and industrial environments, the constant increase of impermeable surfaces has
produced drastic changes in the natural hydrological cycle. Decreasing green areas not only produce
negative effects from a hydrological-hydraulic perspective, but also from an energy point of view,
modifying the urban microclimate and generating, as shown in the literature, heat islands in our cities.
In this context, green infrastructures may represent an environmental compensation action that can be
used to re-equilibrate the hydrological and energy balance and reduce the impact of pollutant load on
receiving water bodies. To ensure that a green infrastructure will work properly, vegetated areas have
to be continuously monitored to verify their health state. This paper presents a ground spectroscopy
monitoring survey of a green roof installed at the University of Calabria fulfilled via the acquisition
and analysis of hyperspectral data. This study is part of a larger research project financed by European
Structural funds aimed at understanding the influence of green roofs on rainwater management and
energy consumption for air conditioning in the Mediterranean area. Reflectance values were acquired
with a field-portable spectroradiometer that operates in the range of wavelengths 350–2500 nm.
The survey was carried out during the time period November 2014–June 2015 and data were acquired
weekly. Climatic, thermo-physical, hydrological and hydraulic quantities were acquired as well and
related to spectral data. Broadband and narrowband spectral indices, related to chlorophyll content
and to chlorophyll–carotenoid ratio, were computed. The two narrowband indices NDVI705 and SIPI
turned out to be the most representative indices to detect the plant health status
Experimental investigation of the productivity of a wet separation process of traditional and bio-plastics
The separation process within a mechanical recycling plant plays a major role in the
context of the production of high-quality secondary raw materials and the reduction of extensive
waste disposal in landfills. Traditional plants for plastic separation employ dry or wet processes
that rely on the different physical properties among the polymers. The hydraulic separator is a
device employing a wet technology for particle separation. It allows the separation of two-polymer
mixtures into two products, one collected within the instrument and the other one expelled through
its outlet ducts. Apparatus performance were analyzed as a function of fluid and solid flow rates, flow
patterns developing within the apparatus, in addition to the density, shape, and size of the polymers.
For the hydraulic configurations tested, a two-way coupling takes place where the fluid exerts an
influence on the plastic particles and the opposite occurs too. The interaction between the solid and
liquid phases determines whether a certain polymer settles within the device or is expelled from the
apparatus. Tests carried out with samples of increasing volumes of solid particles demonstrate that
there are no significant differences in the apparatus effectiveness as far as a two-way interaction takes
place. Almost pure concentrates of Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC),
and Polycarbonate (PC) can be obtained from a mixture of traditional polymers. Tests conducted on
Polylactic Acid (PLA) and Mater-Bi® samples showed that the hydraulic separator can be effectively
employed to separate bio-plastics from conventional plastics with remarkable grade and recovery
PET and PVC separation with hyperspectral Imagery
Traditional plants for plastic separation in homogeneous products employ
material physical properties (for instance density). Due to the small intervals of variability
of different polymer properties, the output quality may not be adequate. Sensing
technologies based on hyperspectral imaging have been introduced in order to classify
materials and to increase the quality of recycled products, which have to comply with
specific standards determined by industrial applications. This paper presents the results of
the characterization of two different plastic polymers—polyethylene terephthalate (PET)
and polyvinyl chloride (PVC)—in different phases of their life cycle (primary raw
materials, urban and urban-assimilated waste and secondary raw materials) to show the
contribution of hyperspectral sensors in the field of material recycling. This is
accomplished via near-infrared (900–1700 nm) reflectance spectra extracted from
hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have
shown that a rapid and reliable identification of PET and PVC can be achieved by using a
simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra.
This resulted in 100% classification accuracy. A sensor based on this identification method
appears suitable and inexpensive to build and provides the necessary speed and
performance required by the recycling industry
Neuroserpin polymers cause oxidative stress in a neuronal model of the dementia FENIB
The serpinopathies are human pathologies caused by mutations that promote polymerisation and intracellular deposition of proteins of the serpin superfamily, leading to a poorly understood cell toxicity. The dementia FENIB is caused by polymerisation of the neuronal serpin neuroserpin (NS) within the endoplasmic reticulum (ER) of neurons. With the aim of understanding the toxicity due to intracellular accumulation of neuroserpin polymers, we have generated transgenic neural progenitor cell (NPC) cultures from mouse foetal cerebral cortex, stably expressing the control protein GFP (green fluorescent protein), or human wild type, G392E or delta NS. We have characterised these cell lines in the proliferative state and after differentiation to neurons. Our results show that G392E NS formed polymers that were mostly retained within the ER, while wild type NS was correctly secreted as a monomeric protein into the culture medium. Delta NS was absent at steady state due to its rapid degradation, but it was easily detected upon proteasomal block. Looking at their intracellular distribution, wild type NS was found in partial co-localisation with ER and Golgi markers, while G392E NS was localised within the ER only. Furthermore, polymers of NS were detected by ELISA and immunofluorescence in neurons expressing the mutant but not the wild type protein. We used control GFP and G392E NPCs differentiated to neurons to investigate which cellular pathways were modulated by intracellular polymers by performing RNA sequencing. We identified 747 genes with a significant upregulation (623) or downregulation (124) in G392E NS-expressing cells, and we focused our attention on several genes involved in the defence against oxidative stress that were up-regulated in cells expressing G392E NS (Aldh1b1, Apoe, Gpx1, Gstm1, Prdx6, Scara3, Sod2). Inhibition of intracellular anti-oxidants by specific pharmacological reagents uncovered the damaging effects of NS polymers. Our results support a role for oxidative stress in the cellular toxicity underlying the neurodegenerative dementia FENIB
Rebound effects caused by withdrawal of MET Kinase inhibitor are quenched by a MET Therapeutic antibody
Abstract
MET oncogene amplification is emerging as a major mechanism of acquired resistance to EGFR-directed therapy in lung and colorectal cancers. Furthermore, MET amplification predicts responsiveness to MET inhibitors currently in clinical trials. Among the anti-MET drugs available, ATP-competitive small-molecule kinase inhibitors abrogate receptor autophosphorylation and downstream activation of ERK1/2 and AKT, resulting in cell-cycle arrest. However, this antiproliferative effect allows persistence of a pool of cancer cells that are quiescent but alive. Once the inhibition is removed, rebound activation of MET-driven cell proliferative pathways and tumor growth may occur, an adverse event observed frequently in clinical settings after drug discontinuation. Here we show that inhibitor withdrawal prompts receptor phosphorylation to levels higher than those displayed at steady-state and generates a rebound effect pushing quiescent cancer cells back into the cell cycle, both in vitro and in experimental tumor models in vivo. Mechanistically, we found that inhibitor treatment blocks MET endocytosis, causing a local increase in the number of receptors at the plasma membrane. Upon inhibitor washout, the receptor is readily rephosphorylated. The initial phosphorylation is not only increased but also prolonged in duration due to downmodulation of a phosphatase-mediated MET-negative feedback loop, which accompanies receptor internalization. Notably, treatment with a MET therapeutic antibody that induces proteolytic cleavage of the receptor at the cell surface substantially prevents this rebound effect, providing a rationale to combine or alternate these mechanistically different types of MET-targeted therapy. Cancer Res; 76(17); 5019–29. ©2016 AACR.</jats:p
Tankyrase inhibition impairs directional migration and invasion of lung cancer cells by affecting microtubule dynamics and polarity signals
Raw data for Fig. S2. (XLSX 48 kb
Hyperspectral image analysis in environmental monitoring: setup of a new tunable filter platform
Nowadays, acquisition and analysis of hyperspectral images represent a new frontier among environmental monitoring techniques. Tunable filters and spectrometers, coupled to appropriate sensors, can be used to acquire the spectral information of large areas (more than 10 km(2)) with great accuracy. The analysis of hyperspectral images provides the spatial distribution (maps) of terrain physical and ecological characteristics. The maps are created by processing the fraction of the incident solar radiation reflected by each object located on the terrain as a function of the wavelength. This feature is known as to "spectral signature". The aim of the research conducted at DICEA - Sapienza University of Rome is to test the applicability and potentiality of these novel instrumentations to applications in natural and artificial systems. In particular, the environmental status of the region crossed by the Sacco river (Latium, Italy) was investigated by analyzing the spectral response given by tree samples located upstream and downstream an industrial area interested by assessed contamination episodes. Data acquired were synthesized in two reflectance indices related to the chlorophyll content: the normalized difference vegetation index and a modified version. The acquisition campaigns described here have helped the set-up and improvement of the hyperspectral image system based on the use of tunable interference filters. Reflectance values and indices suggest tree samples located upstream the contaminated area are 'healthier' than those downstream. (C) 2013 The Authors. Published by Elsevier B.V
Hyperspectral Proximal Sensing of Salix Alba Trees in the Sacco River Valley (Latium, Italy)
Recent developments in hardware and software have increased the possibilities and reduced the costs of hyperspectral proximal sensing. Through the analysis of high resolution spectroscopic measurements at the laboratory or field scales, this monitoring technique is suitable for quantitative estimates of biochemical and biophysical variables related to the physiological state of vegetation. Two systems for hyperspectral imaging have been designed and developed at DICEA-Sapienza University of Rome, one based on the use of spectrometers, the other on tunable interference filters. Both systems provide a high spectral and spatial resolution with low weight, power consumption and cost. This paper describes the set-up of the tunable filter platform and its application to the investigation of the environmental status of the region crossed by the Sacco river (Latium, Italy). This was achieved by analyzing the spectral response given by tree samples, with roots partly or wholly submerged in the river, located upstream and downstream of an industrial area affected by contamination. Data acquired is represented as reflectance indices as well as reflectance values. Broadband and narrowband indices based on pigment content and carotenoids vs. chlorophyll content suggest tree samples located upstream of the contaminated area are ‘healthier’ than those downstream