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1. Quantifying Resilience in Single-Host/Single-Virus Infections

   https://doi.org/10.3390/applmicrobiol5010018  

   Hour, Socheata; Pierce, Andrew; Heng, Sobroney Ying; Plymale, Ruth; Ceballos, Ruben Michael (March 2025, Applied Microbiology)

   Due to theoretical and practical applications in biomedical, environmental, and industrial microbiology, robust metrics for quantifying the virulence of pathogens is vital. For many virus–host systems, multiple virus strains propagate through host populations. Each strain may exhibit a different virulence level. Likewise, different hosts may manifest different levels of host resilience to infection by a given virus. Recent publications have assessed metrics for quantifying virulence (VR) from growth curve data. Regardless of the metric used, a feature that most methods have in common is focus on the exponential growth phase of virus–host interactions. Often ignored is mortality phase. Following a report introducing the Stacy–Ceballos Inhibition Index (ISC), a robust metric to quantify relative virulence (VR) between viruses, we have turned attention to quantifying relative resilience (RR) between hosts in single-virus/single-host (SVSH) experimental infections. Although resilience during viral infection impacts the entire host growth curve, RR has particular biological significance during the mortality phase. In this report, we argue that calculating RR using a modified ISC provides a robust metric for comparisons between SVSH infections. Wet lab data from fusellovirus infections in Sulfolobales, bacteriophage infections in Mycobacteriales, and simulated infected-host growth profiles form the basis for developing this metric, RR, for quantifying resilience. 

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2. Single shot single antenna path discovery in THz networks

   https://doi.org/10.1145/3372224.3380895  

   Ghasempour, Yasaman; Yeh, Chia-Yi; Shrestha, Rabi; Mittleman, Daniel; Knightly, Edward (April 2020, Proceedings of the 26th Annual International Conference on Mobile Computing and Networking)
3. A Single-Aperture, Single-Pixel Reader for Optical Frequency Identification

   https://doi.org/10.1109/ISCAS51556.2021.9401470  

   Fan, Xiaozhe; Hidalgo, James; Leon-Salas, Walter D. (May 2021, 2021 IEEE International Symposium on Circuits and Systems (ISCAS))

   null (Ed.)

   This paper presents a single-aperture, single-pixel reader for communication with Optical Frequency Identification (OFID) tags. OFID tags use solar cells to transmit and receive information wirelessly as well as to harvest radiant energy. Due to its single-aperture architecture, the reader's optical system provides a shared optical path for reception and transmission. Also, physical alignment between the reader and an OFID tag is visually guided using the reader's emitted light, securing a robust data link as long as the OFID tag is illuminated. In this paper, a description of the reader's optical and electronic sub-systems are presented. The transmitter and receiver circuits are described in detail. The transmitter, built with a linear LED driver, achieves a power efficiency of nearly 87%. The receiver, featuring a third-order bandpass filter, reduces both low-frequency and high-frequency ambient noise. A prototype of the reader was fabricated and housed in a custom 3D-printed enclosure. Test results show that the reader is able to receive modulated luminescent signals from an OFID tag at a distance of 1 m and at a data rate of 3 kbps. 

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4. An optical chip for a single atom single photon source

   Zhang, Jin; Oh, Eunji; Yu, Zhaoning; Mehlenbacher, Brandon; Kats, Mikhail; Goldsmith, Randall; Saffman, Mark (June 2021, DAMOP 2021, Bulletin of the American Physical Society)

   We report on progress towards a single atom, single photon source using a fiber connected optical chip. Quantum experiments with cold atoms are burdened by the complexity of the experimental apparatus. Using fiber connectorized optics and a grating MOT suitable for cooling Rb atoms we fabricate a pre-aligned device usable as a single photon source for quantum communication experiments. The device integrates a grating MOT with a single beam dipole trap produced by a fiber and GRIN lens combination. MOT atoms are loaded into the dipole trap and then used as a source of single photons which are collected by the same optical fiber. We will report on details of the fabrication of the optical chip, experimental characterization, and progress towards generating high purity single photons. 

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5. Single enzyme electroanalysis

   https://doi.org/10.1039/D1AN00230A  

   Vannoy, Kathryn J.; Ryabykh, Andrey; Chapoval, Andrei I.; Dick, Jeffrey E. (June 2021, The Analyst)

   Traditional studies of enzymatic activity rely on the combined kinetics of millions of enzyme molecules to produce a product, an experimental approach that may wash out heterogeneities that exist between individual enzymes. Evaluating these properties on an enzyme-by-enzyme basis represents an unambiguous means of elucidating heterogeneities; however, the quantification of enzymatic activity at the single-enzyme level is fundamentally limited by the maximum catalytic rate, k cat , inherent to a given enzyme. For electrochemical methods measuring current, single enzymes must turn over greater than 10 7 molecules per second to produce a measurable signal on the order of 10 −12 A. Enzymes with this capability are extremely rare in nature, with typical k cat values for biologically relevant enzymes falling between 1 and 10 000 s −1 . Thus, clever amplification strategies are necessary to electrochemically detect the vast majority of enzymes. This review details the progress toward the electroanalytical detection and evaluation of single enzyme kinetics largely focused on the nanoimpact method, a chronoamperometric detection strategy that monitors the change in the current-time profile associated with stochastic collisions of freely diffusing entities ( e.g. , enzymes) onto a microelectrode or nanoelectrode surface. We discuss the experimental setups and methods developed in the last decade toward the quantification of single molecule enzymatic rates. Special emphasis is given to the limitations of measurement science in the observation of single enzyme activity and feasible methods of signal amplification with reasonable bandwidth. 

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