2,847 research outputs found
Microwave satellite remote sensing for a sustainable sea
The oceans cover roughly 2/3 of the Earth’s surface and are a fundamental ecosystem regulating climate, weather and representing a huge reservoir of biodiversity and natural resources. The preservation of the oceans is therefore not only relevant on an environmental perspective but also on an economical one. A sustainable approach is requested that cannot be simply achieved by improving technologies but calls for a shared new vision of common goods.Within such a complex and holistic problem, the role of satellite microwave remote sensing to observe marine ecosystem and to assist a sustainable development of human activities must be considered. In such a view the paper is meant. Accordingly, the key microwave sensor technologies are reviewed paying particular emphasis on those applications that can provide effective support to pursue some of the UN Sustainable Development Goals. Three meaningful sectors are showcased:oil and gas, where microwave sensors can provide continuous fine-resolution monitoring of critical infrastructures; renewable energy, where microwave satellite remote sensing allows supporting the management of offshore wind farms during both feasibility and operational stages; plastic pollution, where microwave technologies that exploit signals of opportunity offer large-scale monitoring capability to provide marine litter maps of the oceans
A novel CMB polarization likelihood package for large angular scales built from combined WMAP and Planck LFI legacy maps
We present a CMB large-scale polarization dataset obtained by combining WMAP
Ka, Q and V with Planck 70 GHz maps. We employ the legacy frequency maps
released by the WMAP and Planck collaborations and perform our own Galactic
foreground mitigation technique, which relies on Planck 353 GHz for polarized
dust and on Planck 30 GHz and WMAP K for polarized synchrotron. We derive a
single, optimally-noise-weighted, low-residual-foreground map and the
accompanying noise covariance matrix. These are shown, through
analysis, to be robust over an ample collection of Galactic masks. We use this
dataset, along with the Planck legacy Commander temperature solution, to build
a pixel-based low-resolution CMB likelihood package, whose robustness we test
extensively with the aid of simulations, finding excellent consistency. Using
this likelihood package alone, we constrain the optical depth to reionazation
at C.L., on 54\% of the sky. Adding the
Planck high- temperature and polarization legacy likelihood, the Planck
lensing likelihood and BAO observations we find
in a full CDM exploration. The
latter bounds are slightly less constraining than those obtained employing
\Planck\ HFI CMB data for large angle polarization, that only include EE
correlations. Our bounds are based on a largely independent dataset that does
include also TE correlations. They are generally well compatible with Planck
HFI preferring slightly higher values of . We make the low-resolution
Planck and WMAP joint dataset publicly available along with the accompanying
likelihood code.Comment: The WMAP+LFI likelihood module is available on
\http://www.fe.infn.it/u/pagano/low_ell_datasets/wmap_lfi_legacy
Oil Spills and Slicks imaged by Synthetic Aperture Radar
Oil spills and slicks occur in the ocean around the world due to natural seeps, oil extraction, transportation, and consumption. Satellite synthetic aperture radar (SAR) has proven to be an efficient tool for identifying and classifying oil on the sea surface. This information can be used to monitor
areas for potential illegal marine discharge or to respond to an oil spill incident. When used to monitor shipping lanes or drilling platforms, timely analysis can identify offending parties and lead to prosecution. Following an oil spill such as that from the Deepwater Horizon rig in the Gulf of Mexico in 2010, SAR can be used to direct response activities and optimize available resources
La stima del campo di gravità da dati GOCE: i risultati finali dell’approccio space-wise
In questo lavoro vengono presentati i risultati finali del processamento dati della missione GOCE tramite l’approccio space-wise, da oltre vent’anni studiato ed implementato presso il Politecnico di Milano. In particolare sono stati elaborati i dati di tutta la missione, da novembre 2009 ad ottobre 2013, corrispondente ad oltre cento milioni di epoche. Questo periodo include sia la fase iniziale, durata quasi 3 anni, con il satellite all’altezza nominale di 255 km, sia la fase finale di abbassamento dell’orbita nella quale il satellite è stato lentamente portato fino a 224 km passando attraverso periodi intermedi di misura a quota costante. La fase di preprocessamento dati per la ricerca e la correzione di outlier è stata svolta in modo semi-automatico con una supervisione continua da parte dell’operatore e per questo motivo è stata molto onerosa; tuttavia l’eliminazione degli outlier, presenti in maggior numero nell’ultima fase di abbassamento dell’orbita, è cruciale per il raggiungimento di un risultato soddisfacente, indipendentemente dal metodo di analisi successivamente utilizzato. L’approccio space-wise è sostanzialmente un approccio iterativo di collocazione, che richiede la modellizzazione sia della correlazione temporale dell’errore di misura del gradiometro a bordo del satellite, sia della correlazione spaziale del segnale di gravità che si vuole recuperare. In particolare, l’idea base di questo approccio è quella di ridurre l’enorme mole di dati lungo orbita su una griglia globale all’altezza del satellite applicando la collocazione su aree locali, ciascuna caratterizzata da una covarianza del segnale adattata localmente. In questo modo il livello del filtraggio del dato risulta controllato localmente, diversamente da quanto avviene negli approcci diretto e time-wise dove viene applicata una regolarizzazione globale alla stima ai minimi quadrati dei coefficienti delle armoniche sferiche. Il risultato di questo processamento consiste quindi in griglie globali di derivate seconde del potenziale gravitazionale a una risoluzione spaziale di 0.2°x0.2°. Da queste griglie si deriva un modello globale in armoniche sferiche attraverso integrazione numerica. Sia per le griglie che per i coefficienti armonici viene fornita una stima dell’errore calcolata tramite un’opportuna simulazione Monte Carlo. Il contenuto informativo dei prodotti space-wise è stato valutato confrontandoli con altre griglie e altri modelli globali disponibili. Questo confronto mette in rilievo l’ovvia debolezza della collocazione locale nella stima dei gradi medio-bassi del campo gravitazionale, ma anche la sua miglior capacità di recuperare i più alti degree, ovvero i dettagli del campo. In questo senso l’approccio space-wise può fornire un risultato complementare a quello degli altri due approcci ufficiali all’analisi dati GOCE
Cosmic microwave background cosmology with Planck
Planck is the third-generation space mission aimed at measuring the cosmic microwave background radiation, a relic of the hot Big Bang. Planck ultimate measurement of temperature fluctuations in the cosmic microwave background, together with its leading edge observations of polarization, allowed us to perform unprecedented tests of the cosmological model and derive stringent constraints of fundamental physics. The high sensitivity data also enabled us to obtain the most significant measurement to date of the gravitational lensing of the cosmic microwave background. This represents a novel observable for exploring thirteen billion years of structure formation in the universe. In the paper, I discuss some of the main cosmological constraints we obtained so far and their implications for the standard model of cosmology. I also highlight several key aspects in the data analysis process
Tadalafil modulates aromatase activity and androgen receptor expression in a human osteoblastic cell in vitro model
Purpose Phosphodiesterase type-5 inhibitor (PDE5i)
tadalafil administration in men with erectile dysfunction is
associated with increased testosterone/estradiol ratio, leading
to hypothesize a potential increased effect of androgen
action on target tissues. We aimed to characterize, in a cellular
model system in vitro, the potential modulation of
aromatase and sex steroid hormone receptors upon exposure
to tadalafil (TAD).
Methods Human osteoblast-like cells SAOS-2 were chosen
as an in vitro model system since osteoblasts are target
of steroid hormones. Cells were tested for viability upon
TAD exposure, which increased cell proliferation. Then,
cells were treated with/without TAD for several times to
evaluate potential modulation in PDE5, aromatase (ARO),
androgen (AR) and estrogen (ER) receptor expression.
Results Osteoblasts express significant levels of both PDE5
mRNA and protein. Exposure of cells to increasing concentrations
of TAD (10−8–10−7 M) decreased PDE5 mRNA and
protein expression. Also, TAD inhibited ARO mRNA and
protein expression leading to an increase in testosterone levels
in the supernatants. Interestingly, TAD increased total AR mRNA and protein expression and decreased ERα, with an
increased ratio of AR/ER, suggesting preferential androgenic
vs estrogenic pathway activation.
Conclusions Our results demonstrate for the first time
that TAD decreases ARO expression and increases AR
protein expression in human SAOS-2, strongly suggesting
a new control of steroid hormones pathway by PDE5i.
These findings might represent the first evidence of translational
actions of PDE5i on AR, which leads to hypothesize
a growing relevance of this molecule in men with
prostate cancer long-term treated with TAD for sexual
rehabilitation.
Keywords Tadalafil · Osteoblasts · Aromatase · Androgen
receptor · Estrogen recepto
Components of Purity to Describe the Polarimetric State of a 3-D Field Within the Reverberating Chamber
Reverberating chambers (RCs) are electrically large microwave enclosures in which a random electromagnetic 3-D, i.e., nonplanar, field is generated. To characterize such 3-D fields, a proper polarimetric decomposition is requested. In this article, a new set of parameters, namely the components of purity (CP), first proposed to the electromagnetic compatibility community, is presented. The CP parameters, which stem for the so-called trivial decomposition, are able to classify any 3-D polarimetric field into two states: regular and nonregular. Such characterization is of practical relevance, e.g., for RC isotropy testing
On the Trade-Off Between Enhancement of the Spatial Resolution and Noise Amplification in Conical-Scanning Microwave Radiometers
The ability to enhance the spatial resolution of measurements collected by a conical-scanning microwave radiometer (MWR) is discussed in terms of noise amplification and improvement of the spatial resolution. Simulated (and actual) brightness temperature profiles are analyzed at variance of different intrinsic spatial resolutions and adjacent beams overlapping modeling a simplified 1-D measurement configuration (MC). The actual measurements refer to Special Sensor Microwave Imager (SSM/I) data collected using the 19.35 and the 37.00 GHz channels that match the simulated configurations. The reconstruction of the brightness profile at enhanced spatial resolution is performed using an iterative gradient method which allows a fine tuning of the level of regularization. Objective metrics are introduced to quantify the enhancement of the spatial resolution and noise amplification. Numerical experiments, performed using the simplified 1-D MC, show that the regularized deconvolution results in negligible advantages when dealing with low-overlapping/fine-spatial-resolution configurations. Regularization is a mandatory step when addressing the high-overlapping/low-spatial-resolution case and the spatial resolution can be enhanced up to 2.34 with a noise amplification equal to 1.56. A more stringent requirement on the noise amplification (up to 0.6) results in an improvement of the spatial resolution up to 1.64
Novel strategies for the treatment of myelofibrosis driven by recent advances in understanding the role of the microenvironment in its etiology
Myelofibrosis is the advanced stage of the Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), characterized by systemic inflammation, hematopoietic failure in the bone marrow, and development of extramedullary hematopoiesis, mainly in the spleen. The only potentially curative therapy for this disease is hematopoietic stem cell transplantation, an option that may be offered only to those patients with a compatible donor and with an age and functional status that may face its toxicity. By contrast, with the Philadelphia-positive MPNs that can be dramatically modified by inhibitors of the novel BCR-ABL fusion-protein generated by its genetic lesion, the identification of the molecular lesions that lead to the development of myelofibrosis has not yet translated into a treatment that can modify the natural history of the disease. Therefore, the cure of myelofibrosis remains an unmet clinical need. However, the excitement raised by the discovery of the genetic lesions has inspired additional studies aimed at elucidating the mechanisms driving these neoplasms towards their final stage. These studies have generated the feeling that the cure of myelofibrosis will require targeting both the malignant stem cell clone and its supportive microenvironment. We will summarize here some of the biochemical alterations recently identified in MPNs and the novel therapeutic approaches currently under investigation inspired by these discoveries
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