Optimized White Reflectance in Photonic Network Structures

Three-dimensional disordered networks are receiving increasing attention as versatile architectures for highly scattering materials. However, due to their complex morphology, little is still known about the interplay between their structural and optical properties. Here, we describe a simple algorithm that allows to generate photonic network structures inspired by that of the Cyphochilus beetle, famous for the bright white reflectance of its thin cuticular scales. The model allows to vary the degree of structural anisotropy and filling fraction of the network independently, revealing the key contribution of these two parameters to the overall scattering efficiency. Rigorous numerical simulations show that the obtained structures can exceed the broadband reflectance of the beetle while using less material, providing new insights for the design of advanced scattering materials.Comment: 10 pages, 3 figures. peer reviewed version, published in final form at https://doi.org/10.1002/adom.20190004

Excitability of the motor cortex in patients with migraine changes with the time elapsed from the last attack

BACKGROUND: Motor-evoked potentials (MEPs) produced by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex can be an objective measure of cortical excitability. Previously, MEP thresholds were found to be normal, increased, or even reduced in patients with migraine. In the present study, we determined whether the level of cortical excitability changes with the time interval from the last migraine attack, thereby accounting for the inconsistencies in previous reports. METHODS: Twenty-six patients with untreated migraine without aura (MO) underwent a MEP study between attacks. Their data were then compared to the MEP data collected from a group of 24 healthy volunteers (HVs). During the experiment, the TMS figure-of-eight coil was positioned over the left motor area. After identifying the resting motor threshold (RMT), we delivered 10 single TMS pulses (rate: 0.1 Hz, intensity: 120% of the RMT) and averaged the resulting MEP amplitudes. RESULTS: The mean RMTs and MEP amplitudes were not significantly different between the MO and HV groups. In patients with MO, the RMTs were negatively correlated with the number of days elapsed since the last migraine attack (rho = -0.404, p = 0.04). CONCLUSION: Our results suggest that the threshold for evoking MEPs is influenced by the proximity of an attack; specifically, the threshold is lower when a long time interval has passed after an attack, and is higher (within the range of normative values) when measured close to an attack. These dynamic RMT variations resemble those we reported previously for visual and somatosensory evoked potentials and may represent time-dependent plastic changes in brain excitability in relation to the migraine cycle

Invariance properties of exact solutions of the radiative transfer equation

Abstract In this work, special invariance properties of a class of exact solutions of the radiative transfer equation (RTE) pertaining to a uniform Lambertian illumination of any non-absorbing homogeneous and inhomogeneous volume are presented and discussed. This class of solutions of the RTE traces a reference ground under which light propagation can be studied in a special simplified regime. Despite the difficulties to obtain general solutions of the radiative transfer equation, the condition of Lambertian illumination determines a unique regime of photon transport where quite easy and simple invariant solutions can be obtained in all generality for homogeneous and inhomogeneous geometries. These solutions are invariant both with respect to the geometry (size and shape of the volume) and with respect to the scattering properties, i.e. scattering coefficient, scattering function and homogeneity of the considered domain. Another evident advantage of these solutions is that they are exact solutions known with arbitrary precision and can thus be used as reference standard for photon migration studies

Fake Tourism e immagini. Un’ipotesi di racconto visuale (e ideale) dell’esperienza turistica

The everyday technological abundance and proliferation of media and visual objects have progressively modified our perception and signification processes, but also our existence. Our actions are now often a result of our ongoing relationship between our Being (and our intentions) and media devices through which we tell our stories as subjects-objects of an everyday epos that exists since it is co-constructed, lived and shared from – and into – media environments, resulting in an immediacy that makes a radical mediation, to equalize the ontological differences, possible. Today images are the main code of performative and representative expression of the Social Humanity. Images "exceed", according to Mitchell, by appearing as objects but still maintaining also some potential existential declinations. In the most common form of global human transit, which is tourism, the image becomes a recognizable "sign" of the destination and, because of its immediacy, an object of the research made by the visitor's gaze, according to Urry. The reification of the place makes it simpler and reproducible and the image of the destination is the only one that remains beyond the tourist trip itself. Over and above Benjamin's mechanical reproduction, within the reproducibility of the journey and place, the image becomes paradoxically an expressive limit and a return to the past. Tourists are "guilty" of being driven by a mimetic desire – from the days when the industrialist travelled to imitate the nobleman – and try hard to stand out from that mass of which they are part. Images produced by tourists confirm this flattening of the tourist experience. While tourists could extensively express their individuality through devices, they do nothing but reproduce known, lived and recognizable subjects, narrations and frames. This is the paradox of the image: the expression of the movement of travellers turns out to be their self-imposed cage as the image appears to be a social comfort-zone to escape an unconscious confusion between real and communicated, representation and mystification. This paper will analyse the phenomenon of the fake tourism spread for representing locations that have never been reached and trips that have been faked through media.The everyday technological abundance and proliferation of media and visual objects have progressively modified our perception and signification processes, but also our existence. Our actions are now often a result of our ongoing relationship between our Being (and our intentions) and media devices through which we tell our stories as subjects-objects of an everyday epos that exists since it is co-constructed, lived and shared from – and into – media environments, resulting in an immediacy that makes a radical mediation, to equalize the ontological differences, possible. Today images are the main code of performative and representative expression of the Social Humanity. Images “exceed”, according to Mitchell, by appearing as objects but still maintaining also some potential existential declinations. In the most common form of global human transit, which is tourism, the image becomes a recognizable “sign” of the destination and, because of its immediacy, an object of the research made by the visitor's gaze, according to Urry. The reification of the place makes it simpler and reproducible and the image of the destination is the only one that remains beyond the tourist trip itself. Over and above Benjamin’s mechanical reproduction, within the reproducibility of the journey and place, the image becomes paradoxically an expressive limit and a return to the past. Tourists are “guilty” of being driven by a mimetic desire – from the days when the industrialist travelled to imitate the nobleman – and try hard to stand out from that mass of which they are part. Images produced by tourists confirm this flattening of the tourist experience. While tourists could extensively express their individuality through devices, they do nothing but reproduce known, lived and recognizable subjects, narrations and frames. This is the paradox of the image: the expression of the movement of travellers turns out to be their self-imposed cage as the image appears to be a social comfort-zone to escape an unconscious confusion between real and communicated, representation and mystification. This paper will analyse the phenomenon of the fake tourism spread for representing locations that have never been reached and trips that have been faked through media

Fake tourism e immagini. Un'ipotesi di racconto visuale (e ideale) dell'esperienza turistica

The everyday technological abundance and proliferation of media and visual objects have progressively modified our perception and signification processes, but also our existence. Our actions are now often a result of our ongoing relationship between our Being (and our intentions) and media devices through which we tell our stories as subjects-objects of an everyday epos that exists since it is co-constructed, lived and shared from – and into – media environments, resulting in an immediacy that makes a radical mediation, to equalize the ontological differences, possible. Today images are the main code of performative and representative expression of the Social Humanity. Images "exceed", according to Mitchell, by appearing as objects but still maintaining also some potential existential declinations. In the most common form of global human transit, which is tourism, the image becomes a recognizable "sign" of the destination and, because of its immediacy, an object of the research made by the visitor's gaze, according to Urry. The reification of the place makes it simpler and reproducible and the image of the destination is the only one that remains beyond the tourist trip itself. Over and above Benjamin's mechanical reproduction, within the reproducibility of the journey and place, the image becomes paradoxically an expressive limit and a return to the past. Tourists are "guilty" of being driven by a mimetic desire – from the days when the industrialist travelled to imitate the nobleman – and try hard to stand out from that mass of which they are part. Images produced by tourists confirm this flattening of the tourist experience. While tourists could extensively express their individuality through devices, they do nothing but reproduce known, lived and recognizable subjects, narrations and frames. This is the paradox of the image: the expression of the movement of travellers turns out to be their self-imposed cage as the image appears to be a social comfort-zone to escape an unconscious confusion between real and communicated, representation and mystification. This paper will analyse the phenomenon of the fake tourism spread for representing locations that have never been reached and trips that have been faked through media.The everyday technological abundance and proliferation of media and visual objects have progressively modified our perception and signification processes, but also our existence. Our actions are now often a result of our ongoing relationship between our Being (and our intentions) and media devices through which we tell our stories as subjects-objects of an everyday epos that exists since it is co-constructed, lived and shared from – and into – media environments, resulting in an immediacy that makes a radical mediation, to equalize the ontological differences, possible. Today images are the main code of performative and representative expression of the Social Humanity. Images “exceed”, according to Mitchell, by appearing as objects but still maintaining also some potential existential declinations. In the most common form of global human transit, which is tourism, the image becomes a recognizable “sign” of the destination and, because of its immediacy, an object of the research made by the visitor's gaze, according to Urry. The reification of the place makes it simpler and reproducible and the image of the destination is the only one that remains beyond the tourist trip itself. Over and above Benjamin’s mechanical reproduction, within the reproducibility of the journey and place, the image becomes paradoxically an expressive limit and a return to the past. Tourists are “guilty” of being driven by a mimetic desire – from the days when the industrialist travelled to imitate the nobleman – and try hard to stand out from that mass of which they are part. Images produced by tourists confirm this flattening of the tourist experience. While tourists could extensively express their individuality through devices, they do nothing but reproduce known, lived and recognizable subjects, narrations and frames. This is the paradox of the image: the expression of the movement of travellers turns out to be their self-imposed cage as the image appears to be a social comfort-zone to escape an unconscious confusion between real and communicated, representation and mystification. This paper will analyse the phenomenon of the fake tourism spread for representing locations that have never been reached and trips that have been faked through media

Anisotropic Light Transport in White Beetle Scales

open6sìThe extremely brilliant whiteness shown by the Cyphochilus beetle is generated by multiple scattering of light inside the ultrathin scales that cover its body, whose interior is characterized by an anisotropic nanostructured network of chitin filaments. It is demonstrated that the structural anisotropy of the network is crucial in order to achieve high broadband reflectance from such a thin, low‐refractive‐index system.openCortese, L; Pattelli, L; Utel, F; Vignolini, S; Burresi, M; Wiersma, DSCortese, L; Pattelli, L; Utel, F; Vignolini, S; Burresi, M; Wiersma, D

Bright-white beetle scales optimise multiple scattering of light.

Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement n [291349] and USAF grant FA9550-10-1-0020.This is the final published version, also available from Nature Publishing at http://www.nature.com/srep/2014/140815/srep06075/full/srep06075.html

Effects of axial and ceiling fans on environmental conditions, performance and rumination in beef cattle during the early fattening period

The aim of this study was to assess the effect of two air stirring systems (ceiling fans vs. axial fans) on environment, performance, rumination and activity of beef cattle during the first period after the arrival to the fattening unit. One group of 106 charolais bulls was raised from August to October in a roofed, loose housing facility with straw bedding. Animals were randomly assigned to pens equipped with one of two types of fans: ceiling fans and axial fans. The trial lasted 70 days, and was divided into 3 periods. In the first and third periods fans were in operation, whereas in the second they were switched off. Animals were evaluated for average daily weight gain, cleanliness, dry matter intake, rumination time, activity level and health condition. The temperature-humidity index and the comprehensive climate index were continuously calculated and pens were periodically checked for the dry matter of the bedding. The average temperature-humidity index was lower in the third period (65.5) compared to the first (74.4) and second (75.3) periods (P < 0.001), but was not affected by the air stirring system, while on the contrary the comprehensive climate index was higher in AF than in CF during the first period (27.1 vs. 24.9 °C; P < 0.05). Ceiling fans led to higher dry matter of the bedding in the first (30.6 vs. 45.1%; P < 0.01), second (29.4 vs. 34.3%; P < 0.05) and third periods (22.2 vs. 31.3%; P < 0.05) and to cleaner bulls at the end of the trial. Animals raised with ceiling fans showed higher average daily weight gain (1.20 vs. 1.36 kg/day; P = 0.039), higher daily rumination time in the first period (431 vs. 475 m; P < 0.01) and patterns of rumination and activity compatible with a lower level of heat stress. Based on these results, it appears that ceiling fans are promising tools to be used to reduce heat stress and optimize performance of beef cattle

Infectious Complications After Laparoscopic Appendectomy in Pediatric Patients with Perforated Appendicitis: Is There a Difference in the Outcome Using Irrigation and Suction Versus Suction Only? Results of a Multicentric International Retrospective Study.

Analyzing the recent literature, it seems that the use of irrigation increases the incidence of intra-abdominal abscesses (IAAs) and infectious complications in perforated appendicitis. The aim of this study was to compare peritoneal irrigation and suction versus suction only during laparoscopic appendectomy (LA) for perforated appendicitis in children. MATERIALS AND METHODS: We retrospectively reviewed the records of 699 patients (460 boys and 239 girls, average age 9.8 years) who underwent LA for complicated appendicitis in six international centers of pediatric surgery over a 5-year period. The appendix was perforated with localized peritonitis in 465 cases and diffuse peritonitis in 234 patients. Irrigation + suction was used in 488 cases (group 1 [G1]), whereas suction only was used in 211 cases (group 2 [G2]). RESULTS: No significant difference between the two groups was found in regard to average operative time (P = .23), average time of resumption of oral diet (P = .55), average reprise of gastrointestinal transit (P = .55), and average length of hospital stay (P = .41). As for postoperative complications, the incidence of IAAs was significantly higher in G2 (41/211; 19.4%) compared with G1 (38/488; 7.7%) (P = .0000), whereas no significant difference was found between the two groups in regard to wound infection (G1: n = 2 or 0.4%; G2: n = 4 or 1.8%; P = .05) and small bowel obstruction rates (G1: n = 8 or 1.6%; G2: n = 2 or 0.9%; P = .47). CONCLUSIONS: In contrast with the most recent literature on this topic, our results demonstrated that peritoneal irrigation and suction were associated with a lower rate of postoperative IAA formation compared with the suction-only approach in children with perforated appendicitis. In such cases, peritoneal irrigation and abdominal drainage should be the preferred methods for peritoneal toilette, with no increase in operative time and postoperative morbidity

Bioresorbable multifunctional fiber-optic devices for theranostic and monitoring of tumor

Calcium phosphate glass based single-mode and multi-mode bioresorbable optical fibers were in-house manufactured. Ex-vivo studies were then conducted to test the suitability of these fibers for time gated diffuse optics spectroscopy, photodynamic therapy and diffuse correlation spectroscopy applications which can be respectively employed for the diagnosis, treatment, and monitoring of malignant tissues. The results demonstrated the potential of calcium phosphate glass-based fiber optic devices towards the realization of an implantable multi-functional class of devices with functionalities ranging from cancer detection to monitoring of the healing process all integrated into a single bioresorbable platform. Acknowledgement: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 860185