- ItemPerformance Analysis of Heterogeneous Networks for Robotic Navigation(2023-08-09) Nathan, Hersch; Anwar, Md. Saeid; Ravi, Anuradha; Roy, Nirmalya
- ItemSimultaneous entry as an adaptation to virulence in a novel satellite-helper system infecting Streptomyces species(Nature, 2023-10-31) deCarvalho, Tagide; Mascolo, Elia; Caruso, Steven; López-Pérez, Júlia; Weston-Hafer, Kathleen; Shaffer, Christopher; Erill, IvanSatellites are mobile genetic elements that are dependent upon the replication machinery of their helper viruses. Bacteriophages have provided many examples of satellite nucleic acids that utilize their helper morphogenic genes for propagation. Here we describe two novel satellite-helper phage systems, Mulch and Flayer, that infect Streptomyces species. The satellites in these systems encode for encapsidation machinery but have an absence of key replication genes, thus providing the first example of bacteriophage satellite viruses. We also show that codon usage of the satellites matches the tRNA gene content of the helpers. The satellite in one of these systems, Flayer, does not appear to integrate into the host genome, which represents the first example of a virulent satellite phage. The Flayer satellite has a unique tail adaptation that allows it to attach to its helper for simultaneous co-infection. These findings demonstrate an ever-increasing array of satellite strategies for genetic dependence on their helpers in the evolutionary arms race between satellite and helper phages.
- ItemAccelerating Real-Time Imaging for Radiotherapy: Leveraging Multi-GPU Training with PyTorch(2023-10-02) Obe, Ruth; Kaufmann, Brandt; Baird, Kaelen; Kadel, Sam; Soltani, Yasmin; Cham, Mostafa; Gobbert, Matthias; Barajas, Carlos A.; Jiang, Zhuoran; Sharma, Vijay R.; Ren, Lei; Peterson, Stephen W.; Polf, Jerimy C.Proton beam therapy is an advanced form of cancer radiotherapy that uses high-energy proton beams to deliver precise and targeted radiation to tumors. This helps to mitigate unnecessary radiation exposure in healthy tissues. Realtime imaging of prompt gamma rays with Compton cameras has been suggested to improve therapy efficacy. However, the camera’s non-zero time resolution leads to incorrect interaction classifications and noisy images that are insufficient for accurately assessing proton delivery in patients. To address the challenges posed by the Compton camera’s image quality, machine learning techniques are employed to classify and refine the generated data. These machine-learning techniques include recurrent and feedforward neural networks. A PyTorch model was designed to improve the data captured by the Compton camera. This decision was driven by PyTorch’s flexibility, powerful capabilities in handling sequential data, and enhanced GPU usage. This accelerates the model’s computations on large-scale radiotherapy data. Through hyperparameter tuning, the validation accuracy of our PyTorch model has been improved from an initial 7% to over 60%. Moreover, the PyTorch Distributed Data Parallelism strategy was used to train the RNN models on multiple GPUs, which significantly reduced the training time with a minor impact on model accuracy.
- ItemRobust shaped pulses for arrays of superconducting or semiconductor spin qubits with fixed Ising coupling(2023-10-24) Kanaar, DavidA major current challenge in solid-state quantum computing is to scale qubit arrays to a larger number of qubits. This is hampered by the complexity of the control wiring for the large number of independently tunable interqubit couplings within these arrays. One approach to simplifying the problem is to use a qubit array with fixed Ising (ZZ) interactions. When simultaneously driving a specific subset of qubits in such a system, the dynamics are confined to a set of commuting su(2) subalgebras. Within these su(2)s we describe how to perform X-gates and π/2 ZZ rotations robustly against either leakage, which is the main source of error in transmon qubits, or coupling fluctuations, which is the main source of infidelity in flux or semiconductor spin qubits. These gates together with virtual-z gates form a universal set of gates for quantum computing. We construct this set of robust gates for two-edge, three-edge, and four-edge vertices, which compose all existing superconducting qubit and semiconductor spin qubit arrays.
- ItemReliance on Social Networks and Health Professionals for Health Information in the U.S. Adult Population(Springer, 2023-10-21) Narine, Donnette; Yamashita, Takashi; Punksungka, Wonmai; Helsinger, Abigail; Kramer, Jenna W.; Karam, Rita; Cummins, Phyllis A.Background: The subpopulation of adults depends on non-online health information sources including their social networks and health professionals, to the exclusion of online sources. In view of the digital divide and health information disparities, the roles of race/ethnicity and digital skills are yet to be explored. Methods: A nationally representative sample of 6,830 adults from the Program for the International Assessment of Adult Competencies (PIAAC) was analyzed, using binary logistic regression. Results: Black adults and adults with higher digital skills were less likely to be reliant on non-online health information sources, compared to White adults and those with lower digital skills, respectively. Discussion: Differences in non-online health information source reliance by race/ethnicity and digital skills might be further nuanced by the relevant demographic and socioeconomic characteristics. Increasing digital skills may expand one’s health information sources to include reliable online sources and empower adults to promote their health.