Light scattering from a rough metal surface: theory and experiment

There is still great interest in the determination of microtopographic properties of rough metallic surfaces from light scattering measurements. According to Beckmann–Kirchhoff theory a clear relationship is established between the in-plane angular scattered light intensity and the statistical properties of the surface. We discuss one way to invert this relationship, and we introduce a new iterative procedure to retrieve the height autocorrelation function even for a very rough metallic surface (rms surface roughness of the same order of the optical wavelength). The procedure is eventually applied to the experimental data of a known metallic surface for validation

Scattering Lens Resolves sub-100 nm Structures with Visible Light

The smallest structures that conventional lenses are able to optically resolve are of the order of 200 nm. We introduce a new type of lens that exploits multiple scattering of light to generate a scanning nano-sized optical focus. With an experimental realization of this lens in gallium phosphide we have succeeded to image gold nanoparticles at 97 nm optical resolution. Our work is the first lens that provides a resolution in the nanometer regime at visible wavelengths.Comment: 4 pages, 3 figure

2030 International RHIZomatic Assembly (IRHIZA)

In an interactive design fiction performance we ex- plore the notion of non-human intelligences and their active agency in political discourse. Through speculati- ve means a future context serves as both backdrop and design space for debates between humans and plants, exploring how the scientifically envisioned increased means of communication between the two could sha- pe new solutions and realities. The performance hence deals with an expanded notion of “participation” and debate beyond mere human actors. In a multidiscipli- nary setting, participants stemming from both design and other fields of research (e.g. (ethno)botany, (neuro) biology, anthropology, etc.) will engage in a role-play and joint speculative storytelling effort aimed at explo- ring new questions regarding the challenges and oppor- tunities shaped by such a future world

Filtering and Modulation from Visible to Terahertz using Phase-Change Extraordinary Optical Transmission Metasurfaces

This is the final version.Periodic arrays of sub-wavelength-scale holes in plasmonic metal films are known to provide resonant transmission/reflectance peaks via the extraordinary optical transmission (EOT) effect. Active control of the spectral position of such transmission/reflection peaks can be obtained by adding a layer of phase-change material (PCM) to the EOT device. Switching the PCM layer between its amorphous and crystalline states shifts the spectral position (and usually the amplitude too) of the resonance, so enabling potential applications in the fields of active filtering and sensing (e.g. for multispectral imaging) and optical modulation. Here we report the design, fabrication and characterization of active EOT devices targeted at various important regions of the optical spectrumEngineering and Physical Sciences Research Council (EPSRC

Phase-Change Extraordinary Optical Transmission Metasurfaces for Active Filtering and Modulation from the Visible to Terahertz Regimes

This is the final version. Available from META Conference via the link in this recordPeriodic arrays of sub-wavelength-scale holes in plasmonic metal films can designed to provide resonant transmission/reflectance peaks via the extraordinary optical transmission (EOT) effect. The addition of phase-change materials (PCMs) to such devices can provide a degree of tuneability, cycles of heating and quenching shifting the peak position and/or amplitude depending on the phase-state of the PCM layer. This opens up new application potential in the fields of active filtering and sensing (e.g. for multispectral imaging), displays and optical modulation.Engineering and Physical Sciences Research Council (EPSRC)Qineti

Oral naltrexone treatment for cholestatic pruritus: A double-blind, placebo-controlled study

Background and Aims: The efficacy of currently available therapeutic agents for cholestatic pruritus is often disappointing. The aim of this study was to assess the antipruritic effect of naltrexone, an oral opiate receptor antagonist. Methods: Sixteen patients with pruritus of chronic cholestasis were randomized to receive naltrexone (4-week course of 50 mg naltrexone daily) or placebo. Pruritus, quality of sleep, fatigue (using visual analogue scales), side effects, and liver function were assessed every 2 weeks. Serum naltrexone and 6β-naltrexol concentrations in all patients and 5 healthy controls were measured during the first day of naltrexone treatment. Results: Mean changes with respect to baseline were significantly different, in favor of the naltrexone group, for daytime itching (-54% vs. 8%; P = 0.001) and nighttime itching (-44% vs. 7%, P = 0.003). In 4 naltrexone-treated patients, side effects (transient in 3 cases) consistent with an opiate withdrawal syndrome were noted. No deterioration of the underlying disease was observed. Naltrexone and 6β-naltrexol levels did not differ between patients and controls, and there was no significant association with treatment response. Conclusions: For patients with cholestatic liver disease and itching, refractory to regular antipruritic therapy, oral naltrexone may be an effective and well-tolerated alternative

Strategies and cognitive reserve to preserve lexical production in aging.

In the absence of any neuropsychiatric condition, older adults may show declining performance in several cognitive processes and among them, in retrieving and producing words, reflected in slower responses and even reduced accuracy compared to younger adults. To overcome this difficulty, healthy older adults implement compensatory strategies, which are the focus of this paper. We provide a review of mainstream findings on deficient mechanisms and possible neurocognitive strategies used by older adults to overcome the deleterious effects of age on lexical production. Moreover, we present findings on genetic and lifestyle factors that might either be protective or risk factors of cognitive impairment in advanced age. We propose that "aging-modulating factors" (AMF) can be modified, offering prevention opportunities against aging effects. Based on our review and this proposition, we introduce an integrative neurocognitive model of mechanisms and compensatory strategies for lexical production in older adults (entitled Lexical Access and Retrieval in Aging, LARA). The main hypothesis defended in LARA is that cognitive aging evolves heterogeneously and involves complementary domain-general and domain-specific mechanisms, with substantial inter-individual variability, reflected at behavioral, cognitive, and brain levels. Furthermore, we argue that the ability to compensate for the effect of cognitive aging depends on the amount of reserve specific to each individual which is, in turn, modulated by the AMF. Our conclusion is that a variety of mechanisms and compensatory strategies coexist in the same individual to oppose the effect of age. The role of reserve is pivotal for a successful coping with age-related changes and future research should continue to explore the modulating role of AMF

Influence of shelf-break fronts on shellfish and fish stocks off Argentina

The general circulation pattern in the western boundary of the SW Atlantic is dominated by the opposite flows of Malvinas (-Falkland)and Brazil Current. In the Confluence region both currents separate from the continental slope and flow offshore creating an area of strong contracts and complex dynamics. The shelf-break fronts off Argentina mark the transition between shelf waters of mixed origin and nutrient rich Malvinas waters. Two areas deserve special attention due to the steep gradients introduced by the outflow of important sources of continental waters: the Rio de la Plata and the Magellan Strait to the north and south of the study area. Characteristics of the front is the high primary and secondary production, and the presence of important invertebrate and fish stocks that concentrate along the front to feed or spawn. The area comprises nearly 30 o/o (333 million U$S in 1995)of all Argentine catches of fish and squid. Resources in the area, beyond the EEZ limits, support international fisheries mainly of Russia, Poland and Spain