Adaptive modulation control for visible light communication systems

Visible light communication (VLC) builds on the dual use of lightening infrastructure for communication. Even though the advantages of VLC are well known, as emerging communication paradigm, some open issues still need to be addressed in order to rely on it as a robust communication system. First of all, external interference as an extremely varying signal impacting on the reliability of the VLC system needs to be analyzed. In this paper, we propose a system where the link conditions (in terms of signal-to-noise-ratio (SNR)) drive the modulation scheme and this procedure is managed through the use of an uplink/channel, to assure a feedback path. The receiver is in charge of choosing the modulation scheme matching the requirement in terms of error rate on the basis of the measured SNR after noise mitigation. The feasibility of the system and its effectiveness are evaluated by designing and implementing a complete bi-directional system. In particular, an uplink channel sending the information regarding the specific selected modulation technique has been implemented and the whole system is based on a fine synchronization approach in order to “track” in real time the most suitable modulation scheme. Experimental results show the effectiveness of a bi-directional system in order to implement an adaptive VLC system able to follow the environmental changes (in terms of interference and noise)

A device to characterize optical fibres

ATLAS is a general purpose experiment approved for the LHC collider at CERN. An important component of the detector is the central hadronic calorimeter; for its construction more than 600,000 Wave Length Shifting (WLS) fibres (corresponding to a total length of 1,120 Km) have been used. We have built and put into operation a dedicated instrument for the measurement of light yield and attenuation length over groups of 20 fibres at a time. The overall accuracy achieved in the measurement of light yield (attenuation length) is 1.5% (3%). We also report the results obtained using this method in the quality control of a large sample of fibres.Comment: 17 pages 20 figeres submitted to NIM journa

Assessment of the Trend of Albedo: a Case Study of Palermo

In this paper we propose a case study of urban heat island applied to Palermo. The urban heat island (UHI) is the most studied of the climate effects of settlements. The UHI refers to the generally warm urban temperatures compared to those over surrounding, non-urban, areas. The aim of this paper is to find a connection among the average rise in temperature and the modification of albedo

Krill oil, vitamin D and Lactobacillus reuteri cooperate to reduce gut inflammation

Current research into original therapies to treat intestinal inflammation is focusing on no-drug therapies. KLD is a mixture of krill oil (KO), probiotic Lactobacillus reuteri (LR), and vitamin D (VitD3). The aim of this study was to assess in vitro and in vivo the potential cooperative effects of KLD in reducing gut inflammation. Colorectal adenocarcinoma cell lines, CACO2 and HT29, and C57BL/6 mice were used for in vitro and in vivo analyses, respectively. Cells were exposed to cytomix (interferon gamma + tumour necrosis factor alpha (TNF-a)) to induce inflammation or co-exposed to cytomix and KO, LR and VitD3 alone or to cytomix and KLD. Animals were treated for 7 days with dextran sodium sulphate (DSS) to induce colitis or with DSS and KLD. In vitro assays: F-actin expression was analysed by immunofluorescence; scratch test and trans-epithelial electric resistance test were performed to measure wound healing; adhesion/invasion assays of adhesive and invasive Escherichia coli (AIEC) bacteria were made; mRNA expression of TNF-α, interleukin (IL)-8 and vitamin D receptor (VDR) was detected by quantitative PCR. In vivo assays: body weight, clinical score, histological score and large intestine weight and length were estimated; mRNA expression of TNF-α, IL-1ß, IL-6, IL-10 by quantitative PCR; VDR expression was detected by quantitative PCR and immunohistochemistry. In vitro: KLD restores epithelial cell-cell adhesion and mucosal healing during inflammation, while decreases the adhesiveness and invasiveness of AIEC bacteria and TNF-α and IL-8 mRNA expression and increases VDR expression. In vivo: KLD significantly improves body weight, clinical score, histological score and large intestine length of mice with DSS-induced colitis and reduces TNF-α, IL-1ß and IL-6 mRNA levels, while increases IL-10 mRNA and VDR levels. KLD has significant effects on the intestinal mucosa, strongly decreasing inflammation, increasing epithelial restitution and reducing pathogenicity of harmful commensal bacteria

Rad51 protects nascent DNA from Mre11-dependent degradation and promotes continuous DNA synthesis

The role of Rad51 in an unperturbed cell cycle has been difficult to distinguish from its DNA repair function. Here, using EM to visualize replication intermediates assembled in Xenopus laevis egg extract, we show that Rad51 is required to prevent the accumulation of single-stranded DNA (ssDNA) gaps at replication forks and behind them. ssDNA gaps at forks arise from extended uncoupling of leading- and lagging-strand DNA synthesis. In contrast, ssDNA gaps behind forks, which are prevalent on damaged templates, result from Mre11-dependent degradation of newly synthesized DNA strands and are suppressed by inhibition of Mre11 nuclease activity. These findings reveal direct roles for Rad51 at replication forks, demonstrating that Rad51 protects newly synthesized DNA from Mre11-dependent degradation and promotes continuous DNA synthesis

Assessment of fatigue damage in a fully pearlitic ductile cast iron by evaluation of Acoustic Emission Entropy

Abstract The paper presents the preliminary results of Acoustic Emission (AE) tests on a peralitic ductile cast iron (DCI) subjected to fatigue tensile loading. The focus is on the evaluation of the information Entropy of the AE data, as an innovative tool for a reliable assessment of fatigue damage in DCIs. Two damage indexes are proposed for the identification of the damage evolution and for the prediction of the fracture failure

Emergencies in patients with advanced cancer followed at home.

Abstract CONTEXT: Patients with advanced cancer stay at home for most of their time, and acute problems may occur during home care. Caregivers may call medical services for an emergency, which can result in patients being admitted to the hospital. No data exist on emergencies in patients followed by a home care team. OBJECTIVES: The aim of this multicenter prospective study was to assess the frequency, reasons for, and subsequent course of emergency calls for patients followed at home by a palliative care team. METHODS: A consecutive sample of patients admitted to home care programs was surveyed for a period of seven months. Epidemiological data, and characteristics of emergency calls and outcomes, as well as environmental situations were recorded. RESULTS: Six hundred eighty-nine patients were surveyed; 118 patients (17.1% of the total number of patients surveyed) made one emergency call, 23 made two calls, and four made three calls for a total number of 176 emergency calls. The mean age was 71 years (standard deviation [SD] 13), and the mean Karnofsky status the day before the emergency call was 38 (SD 14). The mean time from admission to the first emergency call was 38.4 days (SD 67), and the mean time from the first emergency call to death was 17.5 days (SD 41.5). No differences were found for age, diagnosis, gender, duration of assistance, and survival between patients making emergency calls and those who did not make a call during an emergency. Twenty-three patients were managed by phone, and 122 were visited at home for the emergency. Calls were prevalently recorded on weekdays and were primarily made by relatives. The most frequent reasons for calling were dyspnea, pain, delirium, and loss of consciousness. Calls were considered justified by home care physicians in most cases. The mean number of relatives present during the emergency home visit was 2.2 (SD 1.5). The intervention was mainly pharmacological and considered satisfactory in the majority of cases. CONCLUSION: Emergency calls are relatively frequent in patients followed at home by a palliative care team. Phone consultation or intervention at home may avoid inappropriate hospital admission