Torsional microresonator in the nonlinear regime: experimental, numerical and analytical characterization

The dynamic behavior of a torsional microresonator is characterized analytically, numerically and experimentally both in the linear and nonlinear regime. Starting from the work presented in [1], here, the highly nonlinear regime is considered and the dynamic pull-in is experienced. Very good agreement between experimental data and numerical model is found also when the analytical methods usually employed to describe the nonlinear dynamic behavior of MEMS (multiple scale methods) are no more accurate. Finally, a numerical limit domain for the microresonator safe operation region in terms of bias and actuation voltages is computed and validated with experimental dat

In Tribute: M. Katherine B. Darmer

The editors of the Chapman Law Review respectfully dedicate this issue to Professor M. Katherine B. Darmer

Negative Refraction Angular Characterization in One-Dimensional Photonic Crystals

Background: Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. Methodology/Principal Findings: By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell’s law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Conclusions/Significance: Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or fo

Suono e Spettacolo. Athanasius Kircher, un percorso nelle Immagini sonore.

The Society of Jesus made great propaganda efforts throughout the seventeenth century and chose the images and the play as a privileged means to communicate and persuade. Athanasius Kircher, a key figure of the seventeenth century, he decided to dominate the wild nature of sound through Phonurgia Nova, which includes a gallery of powerful symbolic images for Baroque aesthetics. The essay, through the grant of the images from the Library of the Department of Mathematics "Guido Castelnuovo" Sapienza University of Rome, aims to understand, through the pictures offered by Kircher, the sound phenomenon and the spectacle that this produces. In Phonurgia Nova a process of dramatization sound effects takes place, often through machines and "visions" applied to the theatrical reality, as experimental and astonishing environment beloved in baroque. Kircher illustrates the sound through explanatory figures, so to dominate the sound through the eyes. Sound is seen, admired and represented: its spectacle not only takes place through the implementation of sound machines or the "wonders" applied to the theater, but even through images, creating create a sense of wonder in in the erudite person of the seventeenth century

REVIEW OF THE CENTRAL AND SOUTH ATLANTIC SHELF AND DEEP-SEA BENTHOS: SCIENCE, POLICY, AND MANAGEMENT

The Central and South Atlantic represents a vast ocean area and is home to a diverse range of ecosystems and species. Nevertheless, and similar to the rest of the global south, the area is comparatively understudied yet exposed to increasing levels of multisectoral pressures. To counteract this, the level of scientific exploration in the Central and South Atlantic has increased in recent years and will likely continue to do so within the context of the United Nations (UN) Decade of Ocean Science for Sustainable Development. Here, we compile the literature to investigate the distribution of previous scientific exploration of offshore (30 m+) ecosystems in the Central and South Atlantic, both within and beyond national jurisdiction, allowing us to synthesise overall patterns of biodiversity. Furthermore, through the lens of sustainable management, we have reviewed the existing anthropogenic activities and associated management measures relevant to the region. Through this exercise, we have identified key knowledge gaps and undersampled regions that represent priority areas for future research and commented on how these may be best incorporated into, or enhanced through, future management measures such as those in discussion at the UN Biodiversity Beyond National Jurisdiction negotiations. This review represents a comprehensive summary for scientists and managers alike looking to understand the key topographical, biological, and legislative features of the Central and South Atlantic.This paper is an output of the UN Ocean Decade endorsed Challenger 150 Programme (#57). Challenger 150 is supported by the Deep Ocean Stewardship Initiative (DOSI) and the Scientific Committee on Oceanic Research’s (SCOR) working group 159 (NSF Grant OCE-1840868) for which KLH is co-chair. AEHB, KLH, KAM, SBu, and KS are supported by the UKRI funded One Ocean Hub NE/S008950/1. TA is supported by the BiodivRestore ERA-NET Cofund (GA N°101003777) with the EU and the following funding organisations: FCT, RFCT, AEI, DFG, and ANR. TA also acknowledges financial support to CESAM by FCT/MCTES (UIDP/50017/2 020+UIDB/50017/2020+ LA/P/0094/2020) through national funds. NB is supported by the John Ellerman Foundation. AB is supported by the German Research Foundation. DH, CO, AFB, LA, SBr, and KS received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818123 (iAtlantic); this output reflects only the author’s view and the European Union cannot be held responsible for any use that may be made of the information contained therein. DH, AF, JT, and CW were additionally supported through the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface” (EXC-2077 – 390741603 by Deutsche Forschungsgemeinschaft). CO also extends thanks to the HWK – Institute for Advanced Study, and PM to Dr. Alberto Martín, retired professor of Universidad Simón Bolívar in Caracas, Venezuela for facilitating references used in the Venezuela section.Peer reviewe

Holodentata gen. nov (Isopoda: Asellota: Paramunnidae) with a description of two new species: H. caeca and H. triangulata from the Southern Ocean

A new genus of Paramunnidae, Holodentata (type species: Paramunna gaussi Vanhoffen, 1914) is erected. The new genus comprises two new species: H. caeca, from the deep Weddell Sea and H. triangulata, from the Ross Sea. The new genus is distinguished by the following characters: article 3 of the antenna short and with strong denticles, mandible palp absent, article 2 of maxilliped palp longest, coxal plates visible in dorsal view in all pereonites, pleotelson broad and laterally denticulated

Optimizing a kinase assay for IKK.beta. on an HTS station

Using a commercially available time-resolved fluorescence resonance energy transfer (TR-FRET)—based assay for IKKβ, the authors have automated the assay procedure on a high-throughput screening station to carry out screening campaigns on multiwell plates. They have determined the Z' factor and optimized volumes, times, and time-resolved fluorescence parameters. They have also compared 2 kinases with different fusion tags, the influence of different enzyme/substrate ratios and of DMSO presence at different concentration. The authors found that glutathione S-transferase (GST)—fused IKKβ shows better signal-to-noise (S/N) ratios over the poly-histidine-tagged variant. The substrate can be used at 50 nM with optimal performances when the enzyme is used at 2 nM. DMSO at 0.2% and 1% only slightly affects the S/N ratio, whereas when used at 2%, the final concentration deriving from a 50-fold dilution from a 5-mM stock solution in pure solvent, S/N undergoes a decrease of about 15%. Under the optimized conditions, the assay Z' factor calculated over 192 data points has an optimized value of 0.881 and allows the testing of 94 molecules in quadruplicate in 140 min