A genetic algorithm-assisted semi-adaptive MMSE multi-user detection for MC-CDMA mobile communication systems

In this work, a novel Minimum-Mean Squared-Error (MMSE) multi-user detector is proposed for MC-CDMA transmission systems working over mobile radio channels characterized by time-varying multipath fading. The proposed MUD algorithm is based on a Genetic Algorithm (GA)-assisted per-carrier MMSE criterion. The GA block works in two successive steps: a training-aided step aimed at computing the optimal receiver weights using a very short training sequence, and a decision-directed step aimed at dynamically updating the weights vector during a channel coherence period. Numerical results evidenced BER performances almost coincident with ones yielded by ideal MMSE-MUD based on the perfect knowledge of channel impulse response. The proposed GA-assisted MMSE-MUD clearly outperforms state-of-the-art adaptive MMSE receivers based on deterministic gradient algorithms, especially for high number of transmitting users

Air bio-contamination control in hospital environment by UV-C rays and HEPA filters in HVAC systems

The contamination of air-handling units is a widespread phenomenon in buildings with air-conditioning systems, including hospitals. The germicide capacity of UV-C rays is known and, in the air-conditioning apparatuses, the UV-C lamps are generally located inside the air ducts. Aim of the paper is to evaluate the effectiveness of UV-C lamps when they are differently placed, i.e. in a position to directly irradiate the HEPA filters surface. We built ad hoc experimental air-conditioning systems, with HEPA filters and UV-C lamps in the two described positions. The results obtained demonstrate that, for disinfection purpose, the direct irradiation of the HEPA filters by UV-C provides better results than irradiation of the air stream and the effectiveness increases when lowering the relative humidity of the air. The survival curves of the tested microorganisms (fungi) show typical tail shaped curves (two steps survival curves). Additional tests using both HEPA filters alone, and HEPA filters plus UV lamps, have been performed measuring the air pressure drop between entrance and exit the HEPA filters and collecting air samples in order to obtain total microbial and fungal count. The results obtained suggest that, at least in experimental conditions described, the radiation on filter surface reduces significantly the microbial load and the pressure drop through the filter, compared to a situation of not-irradiated HEPA filters

Active microcavity and coupled cavities in one-dimensional photonic crystal

The propagation of light in one-dimensional SiO2-TiO2 coupled cavity photonic crystal is investigated. In particular the potential application in light amplification is proposed considering the small group velocity that characterizes the propagation at the edge of the resonance band due to the defects. Then, by means of a transfer-matrix method and a mode matching method code, an estimation of the photon lifetime and of the field intensity in a three-coupled cavity-photonic crystal is reported comparing it with those pertaining to a microcavity photonic crystal. This calculation allows us to underline the role of the light–matter interaction time with respect to that of the number of the active medium layers in the optical amplification

Dexamethasone in acute cardiopulmonary syndrome with hyperinflammatory state

Abstract Introduction Elderly patient hospitalized due to acute heart failure often have a concomitant acute lung disease (acute bronchitis, pneumonia, chronic obstructive pulmonary disease-COPD- exacerbation). Establishing the role of each disease in a clinical picture of acute cardiopulmonary syndrome can be challenging. Procalcitonin has been used as a guide to antibiotic therapy with contrasting results. A common thread of these diseases is inflammation; a hyperinflammatory response determines more serious symptoms and a worse prognosis. Purpose We evaluated the effectiveness of a treatment with dexamethasone in patients with acute cardiopulmonary syndrome and a strong inflammatory response. Materials and methods We evaluated 157 consecutive HFPEF (heart failure with preserved ejection fraction) patients ≥80 years of age, with concomitant symptoms attributable to acute bronchitis, pneumonia, or COPD exacerbation, hospitalized due to worsening dyspnoea, with an NT-proBNP ≥3,000 pg/ml, and a finding X-ray of lung congestion with or without a consolidation. Reactive C Protein was measured. Patients with SARS-CoV-2, indication to corticosteroids use for other clinical conditions or need for mechanical ventilation were excluded. The 96 patients with values>20 mg/dl were randomized into 2 groups: 48 patients were treated open-label with dexamethasone at a dose of 8 mg iv/day for a maximun of ten days, in addition to the usual therapies for acute heart failure and lung disease, while the same number of patients were treated with the usual therapy. In both groups the antibiotic was administered only if the procalcitonin was≥0.25 μg/L. Clinical recovery time, length of hospitalization, in-hospital mortality, the need for a new hospitalization and mortality at one month were evaluated. Results The mean age of the patients was 88±4 years in the dexamethasone group and 87±5 in the usual therapy group. The results are shown in Table 1. Patients treated with dexamethasone experienced a faster clinical recovery and a shorter length of hospitalization. No significant differences were found regarding either in-hospital mortality or need for rehospitalization and mortality at 30 days. Conclusions Very elderly patients with acute cardiopulmonary syndrome and hyperinflammatory state associated with an excessive increase in Reactive Protein C have a favorable response to dexamethasone therapy in addition to the usual therapy in terms of clinical improvement and length of hospitalization. Our case history is small to evaluate a possible improvement in mortality. These findings need to be consolidated from double-blind randomized controlled trials Funding Acknowledgement Type of funding sources: None. Table

Assessment of Natural Resources Use for Sustainable Development - DPSIR Framework for Case Studies in Portsmouth and Thames Gateway, U.K.

This chapter reports on the uses of the DPSIR framework to assess the sustainability of the intertidal environments within the two UK case study areas, Portsmouth and Thames Gateway. It focuses on statutory conservation areas dominated by intertidal habitats. Two are located in Portsmouth (Portsmouth and Langstone Harbours) and four in the Thames Gateway (Benfleet Marshes, South Thames Estuary, Medway Estuary and the Swale in the Thames Gateway). Based on the reduction of a number of pressures and impacts observed in recent decades and the improvement of overall environmental quality, all six SSSIs are considered to be sustainable in the short and medium term. In the future, it is possible that the impacts of climate change, especially sea-level rise, might result in further reduction in the area and/or quality of intertidal habitats. Further integration between conservation and planning objectives (both for urban development and management of flood risk) at local level is needed to support the long-term sustainability of intertidal habitats