On the Effectiveness of OTFS for Joint Radar Parameter Estimation and Communication

We consider a joint radar parameter estimation and communication system using orthogonal time frequency space (OTFS) modulation. The scenario is motivated by vehicular applications where a vehicle (or the infrastructure) equipped with a mono-static radar wishes to communicate data to its target receiver, while estimating parameters of interest related to this receiver. Provided that the radar-equipped transmitter is ready to send data to its target receiver, this setting naturally assumes that the receiver has been already detected. In a point-to-point communication setting over multipath time-frequency selective channels, we study the joint radar and communication system from two perspectives, i.e., the radar parameter estimation at the transmitter as well as the data detection at the receiver. For the radar parameter estimation part, we derive an efficient approximated Maximum Likelihood algorithm and the corresponding Cramér-Rao lower bound for range and velocity estimation. Numerical examples demonstrate that multi-carrier digital formats such as OTFS can achieve as accurate radar estimation as state-of-the-art radar waveforms such as frequency-modulated continuous wave (FMCW). For the data detection part, we focus on separate detection and decoding and consider a soft-output detector that exploits efficiently the channel sparsity in the Doppler-delay domain. We quantify the detector performance in terms of its pragmatic capacity, i.e., the achievable rate of the channel induced by the signal constellation and the detector soft-output. Simulations show that the proposed scheme outperforms concurrent state-of-the-art solutions. Overall, our work shows that a suitable digitally modulated waveform enables to efficiently operate joint radar parameter estimation and communication by achieving full information rate of the modulation and near-optimal radar estimation performance. Furthermore, OTFS appears to be particularly suited to the scope

Acoustic attenuation rate in the Fermi-Bose model with a finite-range fermion-fermion interaction

We study the acoustic attenuation rate in the Fermi-Bose model describing a mixtures of bosonic and fermionic atom gases. We demonstrate the dramatic change of the acoustic attenuation rate as the fermionic component is evolved through the BEC-BCS crossover, in the context of a mean-field model applied to a finite-range fermion-fermion interaction at zero temperature, such as discussed previously by M.M. Parish et al. [Phys. Rev. B 71, 064513 (2005)] and B. Mihaila et al. [Phys. Rev. Lett. 95, 090402 (2005)]. The shape of the acoustic attenuation rate as a function of the boson energy represents a signature for superfluidity in the fermionic component

Architectures and Key Technical Challenges for 5G Systems Incorporating Satellites

Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satellite systems either as a stand-alone solution or as an integration to terrestrial networks in mobile broadband and machine-type communication scenarios. However, typical satellite channel impairments, as large path losses, delays, and Doppler shifts, pose severe challenges to the realisation of a satellite-based NR network. In this paper, based on the architecture options currently being discussed in the standardisation fora, we discuss and assess the impact of the satellite channel characteristics on the physical and Medium Access Control layers, both in terms of transmitted waveforms and procedures for enhanced Mobile BroadBand (eMBB) and NarrowBand-Internet of Things (NB-IoT) applications. The proposed analysis shows that the main technical challenges are related to the PHY/MAC procedures, in particular Random Access (RA), Timing Advance (TA), and Hybrid Automatic Repeat reQuest (HARQ) and, depending on the considered service and architecture, different solutions are proposed.Comment: Submitted to Transactions on Vehicular Technologies, April 201

Glutathione infusion before primary percutaneous coronary intervention: A randomised controlled pilot study

Objective: In the setting of reperfused ST-elevation myocardial infarction (STEMI), increased production of reactive oxygen species (ROS) contributes to reperfusion injury. Among ROS, hydrogen peroxide (H2O2) showed toxic effects on human cardiomyocytes and may induce microcirculatory impairment. Glutathione (GSH) is a water-soluble tripeptide with a potent oxidant scavenging activity. We hypothesised that the infusion of GSH before acute reoxygenation might counteract the deleterious effects of increased H2O2 generation on myocardium. Methods: Fifty consecutive patients with STEMI, scheduled to undergo primary angioplasty, were randomly assigned, before intervention, to receive an infusion of GSH (2500 mg/25 mL over 10 min), followed by drug administration at the same doses at 24, 48 and 72 hours elapsing time or placebo. Peripheral blood samples were obtained before and at the end of the procedure, as well as after 5 days. H2O2 production, 8-iso-prostaglandin F2α (PGF2α) formation, H2O2 breakdown activity (HBA) and nitric oxide (NO) bioavailability were determined. Serum cardiactroponin T (cTpT) was measured at admission and up to 5 days. Results: Following acute reperfusion, a significant reduction of H2O2 production (p=0.0015) and 8-iso-PGF2α levels (p=0.0003), as well as a significant increase in HBA (p<0.0001)and NO bioavailability (p=0.035), was found in the GSH group as compared with placebo. In treated patients, attenuated production of H2O2 persisted up to 5 days from the index procedure (p=0.009) and these changes was linked to those of the cTpT levels (r=0.41, p=0.023). Conclusion: The prophylactic and prolonged infusion of GSH seems to determine a rapid onset and persistent blunting of H2O2 generation improving myocardial cell survival. Nevertheless, a larger trial, adequately powered for evaluation of clinical endpoints, is ongoing to confirm the current finding

The FXR agonist obeticholic acid inhibits the cancerogenic potential of human cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive cancer with high resistance to chemotherapeutics. CCA is enriched in cancer stem cells, which correlate with aggressiveness and prognosis. FXR, a member of the metabolic nuclear receptor family, is markedly down-regulated in human CCA. Our aim was to evaluate, in primary cultures of human intrahepatic CCA (iCCA), the effects of the FXR agonist obeticholic acid (OCA), a semisynthetic bile acid derivative, on their cancerogenic potential. Primary human iCCA cell cultures were prepared from surgical specimens of mucinous or mixed iCCA subtypes. Increasing concentrations (0–2.5 μM) of OCA were added to culture media and, after 3–10 days, effects on proliferation (MTS assay, cell population doubling time), apoptosis (annexin V-FITC/propidium iodide), cell migration and invasion (wound healing response and Matrigel invasion assay), and cancerogenic potential (spheroid formation, clonogenic assay, colony formation capacity) were evaluated. Results: FXR gene expression was downregulated (RT-qPCR) in iCCA cells vs normal human biliary tree stem cells (p < 0.05) and in mucinous iCCA vs mixed iCCA cells (p < 0.05) but was upregulated by addition of OCA. OCA significantly (p < 0.05) inhibited proliferation of both mucinous and mixed iCCA cells, starting at a concentration as low as 0.05 μM. Also, CDCA (but not UDCA) inhibited cell proliferation, although to a much lower extent than OCA, consistent with its different affinity for FXR. OCA significantly induced apoptosis of both iCCA subtypes and decreased their in vitro cancerogenic potential, as evaluated by impairment of colony and spheroid formation capacity and delayed wound healing and Matrigel invasion. In general, these effects were more evident in mixed than mucinous iCCA cells. When tested together with Gemcitabine and Cisplatin, OCA potentiated the anti-proliferative and pro-apoptotic effects of these chemotherapeutics, but mainly in mixed iCCA cells. OCA abolished the capacity of both mucinous and mixed iCCA cells to form colonies when administered together with Gemcitabine and Cisplatin. In subcutaneous xenografts of mixed iCCA cells, OCA alone or combined with Gemcitabine or Cisplatin markedly reduced the tumor size after 5 weeks of treatment by inducing necrosis of tumor mass and inhibiting cell proliferation. In conclusion, FXR is down-regulated in iCCA cells, and its activation by OCA results in anti-cancerogenic effects against mucinous and mixed iCCA cells, both in vitro and in vivo. The effects of OCA predominated in mixed iCCA cells, consistent with the lower aggressiveness and the higher FXR expression in this CCA subtype. These results, showing the FXR-mediated capacity of OCA to inhibit cholangiocarcinogenesis, represent the basis for testing OCA in clinical trials of CCA patients

Detection of pollutant sources in the atmosphere with Lidar/Dial techniques: Results of an experimental campaign in the south of Italy

In the last years, surveying large regions of the atmosphere in an automatic way, for early detection of pollutant sources in urban and industrial areas, has become a strategic objective of various public health organizations. The Lidar/Dial technique has become a well-established laser remote sensing method for atmosphere monitoring. It is often used to probe almost any level of the atmosphere and to acquire information necessary to validate theoretical models about different topics of atmospheric physics. It can also be deployed for environment surveying by monitoring particles, aerosols and molecules. For these reasons, an experimental campaign for evaluating the performances of a Lidar/Dial system in detecting pollutants (particulate and/or chemical compounds) has been carried out in an industrial area in the south of Italy. In this work, a homemade Lidar/Dial system (developed and built by the authors) and the results of the experimental campaign will be presented and discussed. © 2014 AEIT

Different iron-handling in inflamed small and large cholangiocytes and in small and large-duct type intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CCA) represents the second most common primary hepatic malignancy and originates from the neoplastic transformation of the biliary cells. The intrahepatic subtype includes two morpho-molecular forms: large-duct type intrahepatic CCA (iCCA) and small-duct type iCCA. Iron is fundamental for the cellular processes, contributing in tumor development and progression. The aim of this study was to evaluate iron uptake, storage, and efflux proteins in both lipopolysaccharide-inflamed small and large cholangiocytes as well as in different iCCA subtypes. Our results show that, despite an increase in interleukin-6 production by both small and large cholangiocytes, ferroportin (Fpn) was decreased only in small cholangiocytes, whereas transferrin receptor-1 (TfR1) and ferritin (Ftn) did not show any change. Differently from in vitro models, Fpn expression was increased in malignant cholangiocytes of small-duct type iCCA in comparison to large-duct type iCCA and peritumoral tissues. TfR1, Ftn and hepcidin were enhanced, even if at different extent, in both malignant cholangiocytes in comparison to the surrounding samples. Lactoferrin was higher in large-duct type iCCA in respect to small-duct type iCCA and peritumoral tissues. These findings show a different iron handling by inflamed small and large cholangiocytes, and small and large-duct type iCCA. The difference in iron homeostasis by the iCCA subtypes may have implications for the tumor management

Density and spin response functions in ultracold fermionic atom gases

We propose a new method of detecting the onset of superfluidity in a two-component ultracold fermionic gas of atoms governed by an attractive short-range interaction. By studying the two-body correlation functions we find that a measurement of the momentum distribution of the density and spin response functions allows one to access separately the normal and anomalous densities. The change in sign at low momentum transfer of the density response function signals the transition between a BEC and a BCS regimes, characterized by small and large pairs, respectively. This change in sign of the density response function represents an unambiguous signature of the BEC to BCS crossover. Also, we predict spin rotational symmetry-breaking in this system

Viral hepatitis and iron dysregulation: molecular pathways and the role of lactoferrin

The liver is a frontline immune site specifically designed to check and detect potential pathogens from the bloodstream to maintain a general state of immune hyporesponsiveness. One of the main functions of the liver is the regulation of iron homeostasis. The liver detects changes in systemic iron requirements and can regulate its concentration. Pathological states lead to the dysregulation of iron homeostasis which, in turn, can promote infectious and inflammatory processes. In this context, hepatic viruses deviate hepatocytes' iron metabolism in order to better replicate. Indeed, some viruses are able to alter the expression of iron-related proteins or exploit host receptors to enter inside host cells. Lactoferrin (Lf), a multifunctional iron-binding glycoprotein belonging to the innate immunity, is endowed with potent antiviral activity, mainly related to its ability to block viral entry into host cells by interacting with viral and/or cell surface receptors. Moreover, Lf can act as an iron scavenger by both direct iron-chelation or the modulation of the main iron-related proteins. In this review, the complex interplay between viral hepatitis, iron homeostasis, and inflammation as well as the role of Lf are outlined