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In Free Space Optical (FSO) communication systems, atmospheric turbulence distorts the propagating beams, causing a random fading in the received power. This perturbation can be compensated using a multi-aperture receiver that samples the distorted wavefront on different points and adds the various signals coherently. In this work, we report on an adaptive optical receiver that compensates in real time for scintillation in FSO links. The optical front-end of the receiver is entirely integrated in a silicon photonic chip hosting a 2D Optical Antenna Array and a self-adaptive analog Programmable Optical Processor made of a mesh of tunable Mach-Zehnder interferometers. The photonic chip acts as an adaptive interface to couple turbulent FSO beams to single-mode guided optics, enabling energy and cost-effective operation, scalability to systems with a larger number of apertures, modulation-format and data-protocol transparency, and pluggability with commercial fiber optics transceivers. Experimental results demonstrate the effectiveness of the proposed receiver with optical signals at a data rate of 10 Gbit/s transmitted in indoor FSO links where different turbulent conditions, even stronger than those expected in outdoor links of hundreds of meters, are reproduced., (© 2024. The Author(s).)

We demonstrate a temperature and wavelength shift resilient silicon transmission and routing interconnect system suitable for multi-socket interconnects, utilizing a dual-strategy CLIPP feedback circuitry that safeguards the operating point of the constituent photonic building blocks along the entire on-chip transmission-multiplexing-routing chain. The control circuit leverages a novel control power-independent and calibration-free locking strategy that exploits the 2 nd derivative of ring resonator modulators (RMs) transfer function to lock them close to the point of minimum transmission penalty. The system performance was evaluated on an integrated Silicon Photonics 2-socket demonstrator, enforcing control over a chain of RM-MUX-AWGR resonant structures and stressed against thermal and wavelength shift perturbations. The thermal and wavelength stress tests ranged from 27°C to 36°C and 1309.90 nm to 1310.85 nm and revealed average eye diagrams Q-factor values of 5.8 and 5.9 respectively, validating the system robustness to unstable environments and fabrication variations.

Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit's optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems., (© 2022. The Author(s).)

Flexible optical networks require reconfigurable devices with operation on a wavelength range of several tens of nanometers, hitless tuneability (i.e. transparency to other channels during reconfiguration), and polarization independence. All these requirements have not been achieved yet in a single photonic integrated device and this is the reason why the potential of integrated photonics is still largely unexploited in the nodes of optical communication networks. Here we report on a fully-reconfigurable add-drop silicon photonic filter, which can be tuned well beyond the extended C-band (almost 100 nm) in a complete hitless (>35 dB channel isolation) and polarization transparent (1.2 dB polarization dependent loss) way. This achievement is the result of blended strategies applied to the design, calibration, tuning and control of the device. Transmission quality assessment on dual polarization 100 Gbit/s (QPSK) and 200 Gbit/s (16-QAM) signals demonstrates the suitability for dynamic bandwidth allocation in core networks, backhaul networks, intra- and inter-datacenter interconnects., (© 2021. The Author(s).)

Background: The coronavirus disease 2019 (COVID-19) is currently rare in children and they seem to have a milder disease course and better prognosis than adults. However, SARS-Cov-2 pandemic has indirectly caused problems in pediatric medical assistance. In view of this we wanted to draw a picture of what happened during health emergency and analyze future prospects for restarting., Methods: We involved the Italian pediatric scientific societies institutionally collected in the Italian Federation of Associations and Scientific Societies of the Pediatric Area (FIARPED); We sent a questionnaire to all scientific societies about the pediatric care activity during the COVID-19 emergency and future perspectives for the phase of post-containment., Results: The analysis of the questionnaires showed significant decrease of:admission, outpatient visits and specialist consultancy activities during the COVID-19 emergency, primarily linked to the fear of infection. Instead it was increased the serious degree of diseases admitted. Most of scientific societies maintained the relationship with chronic patients through some form of telemedicine, reporting a strong positive opinion about this modality. Finally showed the need to give life a new approach for hospitalizations and outpatient visits through a greater use of telemedicine, educational programs on families and a more decisive role of family pediatricians., Conclusions: Our study highlighted many aspects that can be improved in pediatric care. We think that It will be necessary a new shared strategy to improve the management and continuity of care for pediatric patients, primarily developing a network of collaboration between families, family pediatrician and hospitals and by enhancing the use of new methods of telecommunications.

Background: Young children's healthy development depends on nurturing care, which ensures health, nutrition, responsive caregiving, safety and security, and early learning. Infancy and childhood are characterized by rapid growth and development, and these two factors contribute largely to determining health status and well-being across the lifespan. Identification of modifiable risk factors and prognostic factors during the critical periods of life will contribute to the development of effective prevention and intervention strategies. The NASCITA (NAscere e creSCere in ITAlia) study was created to evaluate physical, cognitive, and psychological development, health status and health resource utilization during the first six years of life in a cohort of newborns, and to evaluate potential associated factors., Methods: NASCITA is an ongoing, dynamic, prospective, population-based birth cohort study of an expected number of more than 5000 newborns who will be recruited in 22 national geographic clusters starting in 2019. It was designed to follow children from birth to school entry age for a wide range of determinants, disorders, and diseases. Recruitment of the newborns (and their parents) will take place during the first routine well-child visit, which takes place at the office of the pediatrician assigned to them by the local health unit of residence, and which is scheduled for all newborns born in Italy within the first 45 days of their life. Data will be web-based and collected by the family pediatricians during each of the 7 standard well-child visits scheduled for all children during their first 6 years of life. Information on every contact with the enrolled children in addition to these prescheduled visits will be also recorded., Discussion: The NASCITA cohort study provides a framework in which children are followed from birth to six-years of age. NASCITA will broaden our understanding of the contribution of early-life factors to infant and child health and development. NASCITA provides opportunities to initiate new studies, also experimental ones, in parts of the cohort, and will contribute relevant information on determinants and health outcomes to policy and decision makers. Cohort details can be found on https://coortenascita.marionegri.it., Trial Registration: Clinicaltrials.gov: NCT03894566. Ethics committee approval: 6 February 2019, Verbale N 59.

A smart, safe, and efficient management of water is fundamental for both developed and developing countries. Several wireless sensor networks have been proposed for real-time monitoring of drinking water quantity and quality, both in the environment and in pipelines. However, surface fouling significantly affects the long-term reliability of pipes and sensors installed in-line. To address this relevant issue, we presented a multi-parameter sensing node embedding a miniaturized slime monitor able to estimate the micrometric thickness and type of slime. The measurement of thin deposits in pipes is descriptive of water biological and chemical stability and enables early warning functions, predictive maintenance, and more efficient management processes. After the description of the sensing node, the related electronics, and the data processing strategies, we presented the results of a two-month validation in the field of a three-node pilot network. Furthermore, self-powering by means of direct energy harvesting from the water flowing through the sensing node was also demonstrated. The robustness and low cost of this solution enable its upscaling to larger monitoring networks, paving the way to water monitoring with unprecedented spatio-temporal resolution.

To describe the infant feeding practices in the general population in Uganda, and to assess the impact of maternal HIV status on these practices, a questionnaire was administered to women attending the follow-up clinics for child vaccination. Among the mothers who were still breastfeeding at the time of interview (N=838), 61.4% of the HIV-infected women had planned to breastfeed for a maximum of 6 months, compared with 12.1% of the HIV-uninfected women (p<0.001). Among the women who were not breastfeeding at the time of interview (N=108), 82.5% of the HIV-infected women had stopped breastfeeding within 3 months, compared with 23.5% of the HIV-uninfected women (p<0.001). Only 2.1% of HIV-infected women seen up to 14 weeks postnatally practised mixed feeding, compared with 23.6% of HIV-uninfected women (p<0.001). After 6 months, however, 30% of the HIV-infected women and 55% of the HIV-uninfected mothers were using mixed feeding, with no significant differences. Programmes for the prevention of mother-to-child transmission of HIV should re-enforce counseling activities to address the issue of early weaning by HIV-infected women, and to support safe breastfeeding up to 6 months.