Three Wave Mixing in Epsilon-Near-Zero Plasmonic Waveguides for Signal Regeneration

Vast improvements in communications technology are possible if the conversion of digital information from optical to electric and back can be removed. Plasmonic devices offer one solution due to optical computing’s potential for increased bandwidth, which would enable increased throughput and enhanced security. Plasmonic devices have small footprints and interface with electronics easily, but these potential improvements are offset by the large device footprints of conventional signal regeneration schemes, since surface plasmon polaritons (SPPs) are incredibly lossy. As such, there is a need for novel regeneration schemes. The continuous, uniform, and unambiguous digital information encoding method is phase-shift-keying (PSK), so we chose to focus on developing a regeneration scheme compatible with PSK. Epsilon-near-zero (ENZ) materials have been shown to support SPP modes and have extremely high conversion rates for harmonic generation at their zero-permittivity wavelength, which makes them particularly desirable for developing signal regeneration devices. We have shown second-harmonic generation (SHG) in free space with simulations consisting of ENZ materials. When integrated into plasmonic waveguides, SHG can be used to conduct phase sensitive amplification (PSA), which allows us to combine phase-squeezing and amplification into a single stage instead of relying on conventional gain media for amplification. PSA can be utilized to design a proof-of-concept signal regeneration device with a smaller overall device footprint than previously demonstrated methods. The development of these methods will contribute towards minimizing device footprints of plasmonic components that require signal regeneration, improving their density and performance

Law, Norms, and Legal Change: Global and Local in China and Japan

The editors of the Michigan Journal of International Law have boldly brought together four articles and commentary that focus on different aspects of the same problem in China and Japan: the relationship between domestic legal change and foreign and/or international law and regulation, soft agreements, norms, or even cultural practices. The compilation is bold in part because scholarship on change in East Asian law and legal systems often suffers from one of two defects. First, it often focuses on purely domestic phenomena in only one system, ignoring the comparative connections. Second, scholars often attack the problem from an exclusively comparative perspective, setting up two apparently different systems, one developed and the other backward or unsophisticated, with accompanying commentary on how they clash or how the latter conforms or measures up to the former

A Hopeful Pedagogy to Critical Thinking

Elements of what we are calling a “hopeful pedagogy” emerged when faculty reflected on the question - Do you think your current approach to develop CT in students is successful? Faculty across disciplines and institutions used the word “hope” to characterize the outcome of their efforts. While attempting to disentangle the “hopeful pedagogy”, we found answers in (a) how faculty defined CT in disciplinary and non-disciplinary contexts; (b) a misalignment between faculty and institutional approaches to CT; (c) a disconnect between faculty and their own approaches to CT, and (d) logistical and curricular issues within general education programs that placed constraints on the ability of faculty to adequately focus on CT. The “hopeful pedagogy” brought to the forefront the serious implications of a misaligned system for student learning, faculty engagement, institutional improvement and accountability

Microwave-assisted synthesis of 3-aminobenzo[b]thiophene scaffolds for the preparation of kinase inhibitors

Microwave irradiation of 2-halobenzonitriles and methyl thioglycolate in the presence of triethylamine in DMSO at 130 °C provides rapid access to 3-aminobenzo[b]thiophenes in 58–96% yield. This transformation has been applied in the synthesis of the thieno[2,3-b]pyridine core motif of LIMK1 inhibitors, the benzo[4,5]thieno[3,2-e][1,4]diazepin-5(2H)-one scaffold of MK2 inhibitors and a benzo[4,5]thieno[3,2-d]pyrimidin-4-one inhibitor of the PIM kinases

Clonal expansion within pneumococcal serotype 6C after use of seven-valent vaccine

Streptococcus pneumoniae causes invasive infections, primarily at the extremes of life. A seven-valent conjugate vaccine (PCV7) is used to protect against invasive pneumococcal disease in children. Within three years of PCV7 introduction, we observed a fourfold increase in serotype 6C carriage, predominantly due to a single clone. We determined the whole-genome sequences of nineteen S. pneumoniae serotype 6C isolates, from both carriage (n = 15) and disease (n = 4) states, to investigate the emergence of serotype 6C in our population, focusing on a single multi-locus sequence type (MLST) clonal complex 395 (CC395). A phylogenetic network was constructed to identify different lineages, followed by analysis of variability in gene sets and sequences. Serotype 6C isolates from this single geographical site fell into four broad phylogenetically distinct lineages. Variation was seen in the 6C capsular locus and in sequences of genes encoding surface proteins. The largest clonal complex was characterised by the presence of lantibiotic synthesis locus. In our population, the 6C capsular locus has been introduced into multiple lineages by independent capsular switching events. However, rapid clonal expansion has occurred within a single MLST clonal complex. Worryingly, plasticity exists within current and potential vaccine-associated loci, a consideration for future vaccine use, target selection and design

Association between Serum 25-Hydroxy Vitamin D Levels and the Prevalence of Adult-Onset Asthma

The major circulating metabolite of vitamin D (25(OH)D) has been implicated in the pathogenesis for atopic dermatitis, asthma and other allergic diseases due to downstream immunomodulatory effects. However, a consistent association between 25(OH)D and asthma during adulthood has yet to be found in observational studies. We aimed to test the association between 25(OH)D and asthma during adulthood and hypothesised that this association would be stronger in non-atopic participants. Using information collected on the participants of the 1958 birth cohort, we developed a novel measure of atopic status using total and specific IgE values and reported history of eczema and allergic rhinitis. We designed a nested case-control analysis, stratified by atopic status, and using logistic regression models investigated the association between 25(OH)D measured at age 46 years with the prevalence of asthma and wheezy bronchitis at age 50 years, excluding participants who reported ever having asthma or wheezy bronchitis before the age of 42. In the fully adjusted models, a 10 nmol/L increase in serum 25(OH)D prevalence had a significant association with asthma (aOR 0.94; 95% CI 0.88–1.00). There was some evidence of an atopic dependent trend in the association between 25(OH)D levels and asthma. Further analytical work on the operationalisation of atopy status would prove useful to uncover whether there is a role for 25(OH)D and other risk factors for asthma

Effects of Defects on Armatures within Helical Flux-Compression Generators

Tubes of aluminum and copper filled with C-4 high-explosive were tested during this study of the effects of explosive flaws and voids, their sizes and locations, and of the effects of armature machining tolerances on the expansion characteristics of armatures within helical flux-compression generators. Flaws and voids were introduced into the explosive fill of 6061-T6 aluminum armatures during assembly. The defects were located along the major axis of the fill, midway between the major axis and the explosive/armature interface, and at the interface. The resulting effects on armature expansion were recorded by high-speed framing camera, intensified charge-coupled display (ICCD) photography and by flash X-ray. Outer and inner surface defects were introduced into OFHC copper and 6061-T6 aluminum armatures via machining. The resulting effects during armature expansion were recorded by framing camera and by ICCD