Cycle slipping in serial receivers for offset binary modulations

A theoretical evaluation is presented of the mean time to first slip for some closed-loop synchronizer schemes to be used in a coherent serial receiver for offset binary modulations. Various modulation formats belonging to this class are considered, and the mean time to first slip is computed for each modulation type for different values of loop bandwidth and signal-to-noise ratio. Theoretical results are confirmed by extensive computer simulations     

An Approach to T&E of Military SDR Platforms and Waveforms: the LANCERS Lab

Software Defined Radio (SDR) is currently one of the main topics of interest in military communications, as well as in civil ones. Since 2002, the Italian Ministry of Defense (MoD) has identified the SDR technology as a strategic capability. In this respect, Italy has become part of the major multinational programs related to military SDR and waveforms, such as ESSOR (European Secure Software Radio) and COALWNW (COALition Wideband Networking Waveform). In addition, the Italian national SDR program (SDR-N) aims at developing a complete family of SDR products, part of which are already available for fielding. In order to develop a governmental capability of Test and Evaluation (T&E) for future SDR, minimizing the risks related to the fielding of this new technology, a dedicated laboratory, called LANCERS lab, has been established in the premises of CSSN ITE (Centro Supporto e Sperimentazione Navale Istituto per le Telecomunicazioni e lElettronica), a research center of the Italian Navy. LANCERS lab gathers the expertise of military technical personnel and University researchers, to provide a twofold capability: developing T&E strategies and procedures for the new tactical communications based on SDR and maintaining knowledge about the state of the art of SDR, fostering new research and development. In this paper we describe the LANCERS lab in all the following aspects: plan of development, organization, current activities, and future perspectives.     

Fatty Acid Amide Hydrolase Deficiency Is Associated with Deleterious Cardiac Effects after Myocardial Ischemia and Reperfusion in Mice

Ischemic cardiomyopathy leads to inflammation and left ventricular (LV) dysfunction. Animal studies provided evidence for cardioprotective effects of the endocannabinoid system, including cardiomyocyte adaptation, inflammation, and remodeling. Cannabinoid type-2 receptor (CB2) deficiency led to increased apoptosis and infarctions with worsened LV function in ischemic cardiomyopathy. The aim of our study was to investigate a possible cardioprotective effect of endocannabinoid anandamide (AEA) after ischemia and reperfusion (I/R). Therefore, fatty acid amide hydrolase deficient (FAAH)^−/− mice were subjected to repetitive, daily, 15 min, left anterior descending artery (LAD) occlusion over 3 and 7 consecutive days. Interestingly, FAAH^−/− mice showed stigmata such as enhanced inflammation, cardiomyocyte loss, stronger remodeling, and persistent scar with deteriorated LV function compared to wild-type (WT) littermates. As endocannabinoids also activate PPAR-α (peroxisome proliferator-activated receptor), PPAR-α mediated effects of AEA were eliminated with PPAR-α antagonist GW6471 i.v. in FAAH^−/− mice. LV function was assessed using M-mode echocardiography. Immunohistochemical analysis revealed apoptosis, macrophage accumulation, collagen deposition, and remodeling. Hypertrophy was determined by cardiomyocyte area and heart weight/tibia length. Molecular analyses involved Taqman^® RT-qPCR and immune cells were analyzed with fluorescence-activated cell sorting (FACS). Most importantly, collagen deposition was reduced to WT levels when FAAH^−/− mice were treated with GW6471. Chemokine ligand-2 (CCL2) expression was significantly higher in FAAH^−/− mice compared to WT, followed by higher macrophage infiltration in infarcted areas, both being reversed by GW6471 treatment. Besides restoring antioxidative properties and contractile elements, PPAR-α antagonism also reversed hypertrophy and remodeling in FAAH^−/− mice. Finally, FAAH^−/−-mice showed more substantial downregulation of PPAR-α compared to WT, suggesting a compensatory mechanism as endocannabinoids are also ligands for PPAR-α, and its activation causes lipotoxicity leading to cardiomyocyte apoptosis. Our study gives novel insights into the role of endocannabinoids acting via PPAR-α. We hypothesize that the increase in endocannabinoids may have partially detrimental effects on cardiomyocyte survival due to PPAR-α activation.     

Influence of sulfur and nitrogen supply on growth,nutrient status and concentration of benzyl‐isothiocyanate in cress (Lepidium sativum L.)

BACKGROUND: The supply of nitrogen (N) and sulfur (S) exerts an interactive effect on glucosinolate (GS) accumulation in Brassica vegetables, but the consequences for the concentration of isothiocyanates (ITCs), released after decomposition of GS by myrosinase, have rarely been investigated. In addition to their phytosanitary function GS have also been discussed as transient S reservoir. RESULTS: Cress (Lepidium sativum, L.) plants were cultivated with varied supply of N (0.5, 1.0 and 2.0 g pot^?1) and S (0, 0.05 and 0.2 g pot^?1). Concentrations of total N and S and hence the N/S ratio responded significantly, as did the concentrations of nitrate and sulfate. Concentrations of benzyl‐ITC, derived from glucotropaeolin (benzyl‐GS), ranged from 6.7 to almost 30 µmol (g dry matter)^?1 and were negatively affected by high N supply. For a given S supply the benzyl‐ITC concentration was inversely related to the N/S ratio, an indicator of the S nutritional status. CONCLUSION: The results do not support the view that GS act as a transient S reservoir. Rather, moderate N and adequate S supplies lead to increased concentrations of this pharmacologically important constituent of cress. Copyright © 2008 Society of Chemical Industry