Wavelength conversion at 10 Gb/s by four-wave mixing over a 30-nm interval

We show that the use of a long semiconductor optical amplifier increases the error-free conversion interval of a four-wave mixing (FWM)-based wavelength converter. 30-nm wavelength down-conversion and 15-nm up-conversion have been obtained at 10 Gb/s. This result is a significant improvement over the previous best performance of a FWM-based wavelength converter and suggests that the full erbium-doped fiber amplifier bandwidth can be covered with FWM wavelength converters

Tight fibred knots without L-space surgeries

We show there exist infinitely many knots of every fixed genus $g\geq 2$ which do not admit surgery to an L-space, despite resembling algebraic knots and L-space knots in general: they are algebraically concordant to the torus knot $T(2,2g+1)$ of the same genus and they are fibred and strongly quasipositive

Editorial: The Benefits of Nature-Based Solutions to Psychological Health

Nature-based solutions (NBS) have been defined by the European Commission as actions aiming to provide environmental, social, and economic benefits through the inclusion of natural features in the urban environment. The exposure to natural environments, including NBS in urban contexts, has been associated with a large number of health benefits (Ulrich et al., 1991; Berman et al., 2008; Spano et al., 2020), particularly mental health and well-being among those most studied. Earlier studies on such benefits have been mainly experimental, investigating the short-term effects of brief exposure to natural environments on stress reduction and cognitive restoration (Kaplan and Kaplan, 1989; Berto, 2005; Nilsson et al., 2010; Carrus et al., 2017). More recently, large-scale epidemiological studies have provided further evidence of the long-term effects of sustained exposure to green spaces on mental health and well-being throughout the life course (Hartig et al., 2014; Gascon et al., 2015; McCormick, 2017; de Keijzer et al., 2020). Several dimensions characterize the human–nature interaction. In this sense, the present Research Topic was intended to provide an overview of studies focusing on the association of exposure to natural environments in urban, peri-urban, and rural settings with psychological well-being and mental health from different perspectives

Providing Focus on Participatory Democracy in Academic Departments of Communication

This article aims to illustrate how academic departments of communication can help contribute to a revitalized public sphere. Some of the projects to enhance participative democracy in order to show one direction in which the public sphere seems to be changing have been highlighted. Academic departments of speech communication can do much to accommodate this change by focusing more on the relationship between communication and democracy. This intention can be formally stated in university planning documents, course titles and outlines, general education guidelines, the establishment of research and consulting consortia, and in partnerships with external institutions. Benefits to the department include clarity of purpose, which can lead to collaboration within the department and with other departments, as well as enhanced educational and research agendas

30-nm wavelength conversion at 10 Gbit/s by four-wave mixing in a semiconductor optical amplifier

Four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is currently the only available strictly transparent wavelength-conversion technique, which is not penalized by phase matching. The span of the conversion is limited primarily by conversion efficiency and signal-to-noise (SNR) issues, both of which are expected to improve with the use of longer SOAs. In this paper, we demonstrate significantly enhanced performance of long converters in a system experiment at 10 Gbit/s. The experiment shows for the first time, to our knowledge, that FWM wavelength down-conversions can span the full gain bandwidth of erbium-doped fiber amplifiers

Morpho-anatomical and physiological traits of Agrostis castellana living in an active geothermal alteration field

Agrostis castellana is one of the few plants colonizing one of the most extreme geothermal alteration fields characterized by low pH and high temperature of soil. The study of species surviving in these multi-stress habitats can help to know more in deep the adaptive ability of plants. In this work morpho-anatomical, functional and physiological traits of leaves of A. castellana living few meters from fumaroles were studied, focusing on their putative ecological significance. Some typical xeromorphic traits occurred in the leaves of these plants: abundant cutinization, cell wall thickening, slightly convolute and adaxially ribbed leaf blades, tissutal reinforcements by sclereids, pubescence, protected stomata and densely packed mesophyll. Abundant pectins, important in both water balance adjusting and as monosaccharide source, were observed in epidermal cell walls. Despite the low value of relative water content, indicative of a disturbed hydric state, oxidative damage, in terms of lipid peroxidation, indicative of membrane damage, was significantly lower than in other plants of the same environment, probably tanks to an adequate antioxidant response based mainly on enzymatic machinery. Interestingly catalase activity was not inhibited by extreme conditions of the geothermal alteration field as in other plants of the same habitat. In conclusion, a cooperation of xeromorphic traits and antioxidant response seems to make A. castellana able to survive in such a prohibitive environment

Testicular cancer and sperm DNA damage: short- and long-term effects of antineoplastic treatment

The aim of this study was to investigate sperm DNA damage induced by chemo- and radiotherapy in patients with testicular cancer to provide data on the extent and persistence of nuclear damage that might affect individual reproductive potential. We evaluated pre- and post-antineoplastic treatment sperm DNA integrity, expressed as DNA Fragmentation Index (DFI), in a large caseload of testicular cancer patients by sperm chromatin structure assay. The mean total DFI for all patients at T0 was 18.0 ± 12.5%. Sperm chromatin profile was markedly impaired at T3 (27.7 ± 17.4%) and T6 (23.2 ± 15.3%), improving considerably at T12 and T24 (14.0 ± 8.9% and 14.4 ± 10.3%). After chemotherapy, we found a marked increase in DFI at T3 and T6 and a significant reduction at T12 and T24 in comparison with the baseline. In contrast, DFI increased at T3 and T6 after radiotherapy but the subsequent reduction was far less marked, reaching baseline values at T12 and T24. Finally, post-treatment DNA damage was not age or histotype dependent, but was more marked in the advanced stage of cancer. In this study, we showed that the chromatin profile may be affected in the months immediately following the end of the treatment, improving after 12-24 months. Our results thus indicate that post-treatment DNA damage is influenced both by the type and intensity of the therapy and by the pathological and clinical stage of the disease. © 2014 American Society of Andrology and European Academy of Andrology

ASSESSING TERRESTRIAL MMS 3D DATA FOR OUTDOOR MULTI-SCALE MODELLING

Mobile Mapping Systems (MMS) have recently benefited from the development of many fusion-based technologies with countless systems development based on cars, drones, trolley, wearable or portable mapping system. The scale of applicating range from the urban to the architectural scale. Recent solution are also based on visual or Lidar SLAM (Simultaneous Localization and Mapping), which substantially takes advantage of environmental features and techniques of continuous co-registration of the clouds, also in case of absence on GNSS positioning measurement. FARO Technology has recently developed the Swift, a fusion-based hybrid solution that integrates the sensors for 3D mapping in a trolley system configuration and recently, an external camera Panocam Theta Z1 is equipping the system enabling the possibility to associate radiometry to the acquired data. The working principle is the exploitation of a system of static and mobile configuration, using the so-called “anchor scans” co-registration as an hybrid intermediate solution between a typical static scan and a profilometers-based MMS point cloud. The co-registered clouds therefore yield a trajectory mode such as SLAM but benefit from the comparable range and density characteristics, according to user-customized settings, of static scans, with a duration of a few seconds per scan and a few minutes overall. In the present research the Swift System is tested in two different context and the assessment are conducted aimed at satisfying both the urban and the architectural scale instances in the direction of improving further evaluations