Asymptotics of polygons in restricted geometries subject to a force

International audienceWe consider self-avoiding polygons in a restricted geometry, namely an infinite L × M tube in Z3. These polygons are subjected to a force f, parallel to the infinite axis of the tube. When f > 0 the force stretches the polygons, while when f < 0 the force is compressive. In this extended abstract we obtain and prove the asymptotic form of the free energy in the limit f → −∞. We conjecture that the f → −∞ asymptote is the same as the free energy of Hamiltonian polygons, which visit every vertex in a L × M × N box

Maximizing the First-Year Planning Period for Scholarly Publications: Implications for Prospective CYFAR Grant Recipients

One of CYFAR\u27s unique features is the built-in planning year for all grant recipients. We present our evaluation team’s approach during year 1 to establish a foundation and plan for scholarly publications during funding years 2–5. The systematic literature review provided the team with a better understanding of the culture and context of the project’s target population. Collaboration between PI/Co-PI and Evaluator served as a powerful tool to achieving this goal. Not only does this model benefit future CYFAR grant recipients’ and Extension professionals’ curriculum development and program evaluation, it can also inform recruitment efforts and community partnership development

Asymptotics of polygons in restricted geometries subject to a force

We consider self-avoiding polygons in a restricted geometry, namely an infinite L × M tube in Z3. These polygons are subjected to a force f, parallel to the infinite axis of the tube. When f > 0 the force stretches the polygons, while when f < 0 the force is compressive. In this extended abstract we obtain and prove the asymptotic form of the free energy in the limit f → −∞. We conjecture that the f → −∞ asymptote is the same as the free energy of Hamiltonian polygons, which visit every vertex in a L × M × N box

Surface-near domain engineering in multi-domain x-cut lithium niobate tantalate mixed crystals

Lithium niobate and lithium tantalate are among the most widespread materials for nonlinear, integrated photonics. Mixed crystals with arbitrary Nb-Ta ratios provide a new degree of freedom to tune materials properties, such as the birefringence, but also leverage the advantages of the singular compounds, for example, by combining the thermal stability of lithium tantalate with the larger nonlinear or piezoelectric constants of lithium niobate. Periodic poling is the prerequisite for any nonlinear optical application. For mixed crystals this has been challenging so far due to the lack of homogeneous, mono-domain crystals, which severely inhibit domain growth and nucleation. In this work we demonstrate that surface-near ($< 1$~$\mu$m depth) periodic poling on x-cut lithium niobate tantalate mixed crystals can be achieved via electric field poling and lithographically structured electrodes. We find that naturally occurring head-to-head or tail-to-tail domain walls in the as-grown crystal inhibit domain inversion at a larger scale. However, periodic poling is possible, if the gap size between the poling electrodes is of the same order of magnitude or smaller than the average size of naturally occurring domains. This work provides the basis for the nonlinear optical application of lithium niobate tantalate mixed crystals

Evidence for replicative mechanism in a CHD7 rearrangement in a patient with CHARGE syndrome

Haploinsufficiency of CHD7 (OMIM# 608892) is known to cause CHARGE syndrome (OMIM# 214800). Molecular testing supports a definitive diagnosis in approximately 65-70% of cases. Most CHD7 mutations arise de novo, and no mutations affecting exon-7 have been reported to date. We report on an 8-year-old girl diagnosed with CHARGE syndrome that was referred to our laboratory for comprehensive CHD7 gene screening. Genomic DNA from the subject with a suspected diagnosis of CHARGE was isolated from peripheral blood lymphocytes and comprehensive Sanger sequencing, along with deletion/duplication analysis of the CHD7 gene using multiplex ligation-dependent probe amplification (MLPA), was performed. MLPA analysis identified a reduced single probe signal for exon-7 of the CHD7 gene consistent with potential heterozygous deletion. Long-range PCR breakpoint analysis identified a complex genomic rearrangement (CGR) leading to the deletion of exon-7 and breakpoints consistent with a replicative mechanism such as fork stalling and template switching (FoSTeS) or microhomology-mediated break-induced replication (MMBIR). Taken together this represents the first evidence for a CHD7 intragenic CGR in a patient with CHARGE syndrome leading to what appears to be also the first report of a mutation specifically disrupting exon-7. Although likely rare, CGR may represent an overlooked mechanism in subjects with CHARGE syndrome that can be missed by current sequencing and dosage assays

A Local Superlens

Superlenses enable near-field imaging beyond the optical diffraction limit. However, their widespread implementation in optical imaging technology so far has been limited by large-scale fabrication, fixed lens position, and specific object materials. Here we demonstrate that a dielectric lamella of subwavelength size in all three spatial dimensions behaves as a compact superlens that operates at infrared wavelengths and can be positioned to image any local microscopic area of interest on the sample. In particular, the lamella superlens may be placed in contact with any type of object and therefore enables examination of hard-to-scan samples, for example, with high topography or in liquids, without altering the specimen design. This lamella-based local superlens design is directly applicable to subwavelength light-based technology, such as integrated optics

A MOOC-based flipped classroom: the pre-diploma students’ perspectives / Imelia Laura Daneil ... [et al.]

The Massive open online course (MOOC) is a move toward greater openness in higher education. The current literature on MOOCs, covering research on their effectiveness to accommodate different students’ abilities showed conflicting results in this regard. With limited studies on a MOOC-based flipped classroom in Malaysian higher education, this study explored the perceived usefulness and perceived ease-of-use of the MOOC-based flipped classrooms among the pre-diploma students who enrolled in the English MOOC. The pre-diploma students were interviewed to respond to these concerns. Questionnaires were also administered to all registered users to analyze the perceived use and ease-ofuse of the MOOCs when used in flipped classrooms. The study found the significant challenges faced by pre-diploma students in terms of the content, language, and technical aspects of MOOCs. Therefore, possible solutions to these challenges were identified and discussed. These findings can help the policy makers explore strategies for MOOC's future development, implementation, and success in the context of higher education in Malaysia specifically for pre-diploma students