Work in Progress: Mastery-Based Grading in an Introduction to Circuits Class

Circuits is often the first required course in an electrical engineering curriculum that demands application of multiple concepts from prerequisite math and physics courses. This integration of knowledge can be a challenge for many students. Effective teaching methods can enhance the overall learning experience, increase program retention, and improve student understanding of foundational topics in electrical engineering. This paper outlines a mastery-based grading structure implemented in a sophomore-level circuits class. The focus is placed at this level because the course is a critical prerequisite for many other courses in the electrical and computer engineering (ECE) curriculum. The knowledge that students are expected to gain in circuits is paramount to successful completion of their degree. However, faculty often observe that many students pass circuits without being able to consistently apply many of the fundamental concepts therefore causing them to struggle through subsequent courses. The overall goal of this mastery-based grading scheme is to create a more positive student learning experience that also translates to improved long-term performance. It also helps to alleviate some level of test anxiety and the stress students feel in a fast-paced, rigorous course such as circuits

Adhesion, Stiffness and Instability in Atomically Thin MoS2 Bubbles

We measured the work of separation of single and few-layer MoS2 membranes from a SiOx substrate using a mechanical blister test, and found a value of 220 +- 35 mJ/m^2. Our measurements were also used to determine the 2D Young's modulus of a single MoS2 layer to be 160 +- 40 N/m. We then studied the delamination mechanics of pressurized MoS2 bubles, demonstrating both stable and unstable transitions between the bubbles' laminated and delaminated states as the bubbles were inflated. When they were deflated, we observed edge pinning and a snap-in transition which are not accounted for by the previously reported models. We attribute this result to adhesion hysteresis and use our results to estimate the work of adhesion of our membranes to be 42 +- 20 mJ/m^2

A CMOS Synapse Design Implementing Tunable Asymmetric Spike Timing-Dependent Plasticity

A CMOS synapse design is presented which can perform tunable asymmetric spike timing-dependent learning in asynchronous spiking neural networks. The overall design consists of three primary subcircuit blocks, and the operation of each is described. Pair-based Spike Timing-Dependent Plasticity (STDP) of the entire synapse is then demonstrated through simulation using the Cadence Virtuoso platform. Tuning of the STDP curve learning window and rate of synaptic weight change is possible using various control parameters. With appropriate settings, it is shown the resulting learning rule closely matches that observed in biological systems

A STUDY EXAMINING THE EFFECTIVENESS OF THE ME! LESSONS TO TEACH SELF-AWARENESS AND SELF-ADVOCACY TO STUDENTS WITH DISABILITIES

A small-n design called the multi-element baseline design with a pre-intervention baseline and a phenomenological approach was used to examine the effectiveness of an instructional program called ME! Lessons to Teach Self-Awareness and Self-Advocacy when used with high school students with disabilities. Six 9th grade students, one special education teacher, and six parents participated in this five-week study.The ME! Lessons to Teach Self-Awareness and Self-Advocacy include 10 instructional units with two to four lessons in each unit linked to the Oklahoma PASS standards. ME! topics include special education rights and responsibilities, IEP documents, understanding of strengths and weaknesses, accommodations, and appropriate use of self-advocacy skills. The lessons use a variety of activities including role-playing, case studies, PowerPoint presentations, teacher-directed instruction, video clips, a student research project, and student examination of their IEP documents. Students developed a portfolio while completing the lessons, which contained information needed for future self-advocacy interactions. The purpose of the ME! curriculum is to facilitate the teaching and learning of self-awareness and self-advocacy knowledge and skills. The long-term goal of the curriculum is to develop self-aware adults who advocate for their needs in education and employment in a meaningful productive way.Results indicate that the ME! lessons increased students' self-awareness and self-advocacy knowledge and behaviors. Additionally, parent, student, and teacher reported that they believed the lesson content was useful and practical

Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2

We demonstrate the continuous and reversible tuning of the optical band gap of suspended monolayer MoS2 membranes by as much as 500 meV by applying very large biaxial strains. By using chemical vapor deposition (CVD) to grow crystals that are highly impermeable to gas, we are able to apply a pressure difference across suspended membranes to induce biaxial strains. We observe the effect of strain on the energy and intensity of the peaks in the photoluminescence (PL) spectrum, and find a linear tuning rate of the optical band gap of 99 meV/%. This method is then used to study the PL spectra of bilayer and trilayer devices under strain, and to find the shift rates and Gr\"uneisen parameters of two Raman modes in monolayer MoS2. Finally, we use this result to show that we can apply biaxial strains as large as 5.6% across micron sized areas, and report evidence for the strain tuning of higher level optical transitions.Comment: Nano Lett., Article ASA

An Archeological Reconnaissance of the Bobby Jones Expressway Corridor, Aiken County, South Carolina

https://scholarcommons.sc.edu/archanth_books/1108/thumbnail.jp

Voltage gated inter-cation selective ion channels from graphene nanopores

With the ability to selectively control ionic flux, biological protein ion channels perform a fundamental role in many physiological processes. For practical applications that require the functionality of a biological ion channel, graphene provides a promising solid-state alternative, due to its atomic thinness and mechanical strength. Here, we demonstrate that nanopores introduced into graphene membranes, as large as 50 nm in diameter, exhibit inter-cation selectivity with a ~20x preference for K+ over divalent cations and can be modulated by an applied gate voltage. Liquid atomic force microscopy of the graphene devices reveals surface nanobubbles near the pore to be responsible for the observed selective behavior. Molecular dynamics simulations indicate that translocation of ions across the pore likely occurs via a thin water layer at the edge of the pore and the nanobubble. Our results demonstrate a significant improvement in the inter-cation selectivity displayed by a solid-state nanopore device and by utilizing the pores in a de-wetted state, offers an approach to fabricating selective graphene membranes that does not rely on the fabrication of sub-nm pores

Disruption of beta cell acetyl-CoA carboxylase-1 in mice impairs insulin secretion and beta cell mass

Aims/hypothesis Pancreatic beta cells secrete insulin to maintain glucose homeostasis, and beta cell failure is a hallmark of type 2 diabetes. Glucose triggers insulin secretion in beta cells via oxidative mitochondrial pathways. However, it also feeds mitochondrial anaplerotic pathways, driving citrate export and cytosolic malonyl-CoA production by the acetyl-CoA carboxylase 1 (ACC1) enzyme. This pathway has been proposed as an alternative glucose-sensing mechanism, supported mainly by in vitro data. Here, we sought to address the role of the beta cell ACC1-coupled pathway in insulin secretion and glucose homeostasis in vivo. Methods Acaca, encoding ACC1 (the principal ACC isoform in islets), was deleted in beta cells of mice using the Cre/loxP system. Acaca floxed mice were crossed with Ins2cre mice (βACC1KO; life-long beta cell gene deletion) or Pdx1creER mice (tmx-βACC1KO; inducible gene deletion in adult beta cells). Beta cell function was assessed using in vivo metabolic physiology and ex vivo islet experiments. Beta cell mass was analysed using histological techniques. Results βACC1KO and tmx-βACC1KO mice were glucose intolerant and had defective insulin secretion in vivo. Isolated islet studies identified impaired insulin secretion from beta cells, independent of changes in the abundance of neutral lipids previously implicated as amplification signals. Pancreatic morphometry unexpectedly revealed reduced beta cell size in βACC1KO mice but not in tmx-βACC1KO mice, with decreased levels of proteins involved in the mechanistic target of rapamycin kinase (mTOR)-dependent protein translation pathway underpinning this effect. Conclusions/interpretation Our study demonstrates that the beta cell ACC1-coupled pathway is critical for insulin secretion in vivo and ex vivo and that it is indispensable for glucose homeostasis. We further reveal a role for ACC1 in controlling beta cell growth prior to adulthood