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Modal Analysis of a Double-Layer Line Waveguide Inside and Outside the Homogenization Regime
No full textThe dispersion features of the line wave supported by a double-layer line-wave waveguide with a cross section exhibiting central symmetry are determined through full-wave simulations of a truncated structure and a numerical post-processing fitting procedure. Within the low-frequency homog-enization regime, in which the unit cell of the constituent metasurfaces is a small fraction of the free-space wavelength, the phase constant of the line wave is thus retrieved rigorously. The adopted approach has been also extended to higher frequencies beyond the homogenization limit, where higher order space harmonics become non-negligible, the line wave is thus to be regarded as a Bloch mode of a periodic structure, and the associated stopband regimes are shown to emerge
Ingestion of prey intensifies microplastic load in Mediterranean commercial fish
No full textWe describe the ingestion of plastics by four edible fish species from the Western Mediterranean Sea (Fiumicino,
Italy): Micromesistius poutassou, Mullus barbatus, Sardina pilchardus, and Trachurus trachurus. Microparticles
smaller than 1 mm, particularly blue fibres made of cellophane, are the most found in terms of size, colour,
shape, and polymer. The highest level of contamination was found in Sardina pilchardus and in stomachs containing
prey across all species. We have gathered evidence from commercially relevant fishes, of which two can
be good bioindicators of microplastics (M. barbatus and T. trachurus), and one is poorly investigated (M. poutassou)
in order to contribute to the overall assessments of the MP-induced risks for the Mediterranean ecosystem
and human activity
Un bollo in planta pedis su clibanio da Spoletino, Viterbo
No full textSi presenta un frammento pertinente ad un clibanio, forma ceramica connessa con la cottura sub testu menzionata da fonti letterarie, proveniente dallo scavo della cisterna di età romana in località Spoletino (VT), condotto negli anni 2014-2018. Sul frammento è un bollo in planta pedis, la cui più plausibile appare essere: C(ai) ...cimari / fec(it) Myrinus
Inhibition of return emerges with non-predictive spatial cueing of the stop-signal
No full textThe ability to suppress an inappropriate response can be influenced by several factors, including providing information on where to pay attention. For example, the spatial prediction of the stop signal location enhances inhibitory control in a Stop Signal Task. Here, we test whether a non-predictive spatial cueing improves inhibitory control as well. In this experiment, participants observed a vertical bar moving from a central position toward one of two circles on the screen. They were asked to press a key when the bar's motion was interrupted (go signal). In 25% of the trials (stop signal trials), after a variable delay following the go signal, a visual target (stop signal) appeared in one of the circles, requiring participants to inhibit their response to the go signal. In half of these trials, the stop signal appeared on the same side as the go signal (valid condition), and in the other half, it appeared on the opposite side (invalid condition). Our results show a facilitation effect for stop trials in the invalid condition compared to the valid condition, for targets occurring from 300 ms onward the go signal. This suggests an involvement of Inhibition of Return (IOR) in affecting the stop signal detection during motor control. Our findings provide new insights into the interaction between attentional processes and motor control, highlighting a temporally focused influence of exogenous attention in shaping motor inhibition
Gesturing mathematics a pragmatist-enactive perspective
No full textThe article explores the theoretical elements that can support a pragmatist-enactive approach to mathematical cognition through the concept of "gesture." Exploring this conceptual tool highlights its potential fruitfulness in understanding the development of mathematical reasoning from a sensorimotor perspective, offering a possible solution to filling the cognitive gap between contentless and contentful forms of cognition. The main aim of the article is to propose a pluralistic approach to gesture that seeks to combine multiple related meanings of gesture through shared features related to the motility, continuity, directionality, and communicativeness of gesture-considering these different meanings as evolving via biological, ecological, and cultural processes. This evolution is accompanied by a semantic complexification of the concept as it progresses towards greater abstraction. The article first analyses recent theories on the embodied and enacted origins of mathematical cognition to deploy this proposal. After that, it introduces the work of mathematician Giuseppe Longo, which focuses on the importance of gesture in mathematical cognition. Longo's proposal presents valuable insights but raises criticisms about his interpretation of intentionality and gesture. In particular, his broad interpretation of intention may be misleading. Furthermore, Longo employs four distinct meanings of "gesture," resulting in theoretical confusion. To clarify these issues, I suggest framing Longo's argument within a pragmatist context. From this perspective, gesture is the sensorimotor element that contributes to the making-sense processes in interactions between organisms and between organisms and their environment, which underlie the emergence of abstract language and formal reasoning. Gesture is thus both central to biosemiotic processes and essential to the sensorimotor coordination that makes the graphic sign useful to abstract concepts. The main aim of the article is to propose a pluralistic approach to gesture that seeks to integrate multiple meanings of gesture closely related through common features-motility, continuity, direction, and communication-regarding these different meanings as evolving through biological, ecological, and cultural processes, which are accompanied by a semantic complexification of the concept as we move towards greater abstraction. This investigation is part of a broader project that aims to promote a Pragmatist Enactivism, which seeks to consolidate the "pragmatic turn" in 4EA cognition (embodied, embedded, extended, enacted, affective)
Current status and medium- and long-term variation of soil erosion by water in China
No full textSoil erosion is the primary factor causing the loss of soil resources and land degradation. Clarifying the current status of soil erosion in China and the characteristics of future changes under different pathways of development is important to the global management of soil resources, food security, and ecosystem services. We used the revised universal soil loss equation and the most recent and reliable soil and environmental data to characterize soil erosion in China at present and under typical Shared Socioeconomic Pathways and Representative Concentration Pathways (i.e., SSP1–2.6 and SSP5–8.5) in the medium- and long-term future (2050 and 2100). The current average rate of soil erosion in China was 14.78 t ha-1 yr-1, with a total amount of about 14.0 Pg yr-1. The amount of total erosion increased by 5.0 %, 10.8 %, 9.9 %, and 25.9 % for scenarios 2050_SSP1–2.6, 2050_SSP5–8.5, 2100_SSP1–2.6, and 2100_SSP5–8.5, respectively, compared to the baseline amount in 2010. The contribution of climate change and land use to the increase in erosion ranged from 9.5 % to 31.5 % and -6.95 % to -1.78 %, respectively, with the contribution of climate change about 2.36- to 7.54-fold larger than the contribution of land use. Converting arable barren land into forest and grassland or adopting conservation tillage practices for farmland, could nevertheless effectively offset the increase in erosion under the four future scenarios. This study provides data and a scientific basis for managing soil erosion in China and provides a useful reference for conserving global land resources and formulating policies to cope with climatic and environmental changes