Morgantown High School

Motivated by predictions that globular clusters associated with nearby giant elliptical galaxies are prime environments for detecting fast radio bursts (FRBs) from magnetars, we report on a targeted high-sensitivity search across five local massive elliptical galaxies. We utilized the GREENBURST single-pulse search pipeline and the VEGAS backend on the Green Bank Telescope (GBT) to conduct an L-band (1.4 GHz) survey for FRBs in each target environment. We discovered FRB 20240817A in the direction of M49 (NGC 4472) which has a pulse width of 15 ms, a signal-to-noise ratio of 13, and a dispersion measure (DM) of 983 cm^-3 pc. Although a Bayesian spatial association framework initially flags M49 as the host, carefully accounting for the foreground electron column contributions from the Milky Way and both the Virgo intracluster medium and M49's hot gaseous halo (∼300-400 cm^-3 pc combined) strongly disfavours a physical connection. We conclude that FRB 20240817A is a background event. We also identified a repeating cluster of three low-significance pulses from the direction of M49 at a physically plausible DM of 150-160 cm^-3 pc. Accounting for the fraction of each target's extended globular cluster distribution observed, the absence of unambiguous, host-localized bursts allows us to place a joint upper limit on the intrinsic burst rate of a single active source within these systems of R_0 < 0.028 hr^-1 (and an integrated rate limit of <1.0 hr^-1 for M49), lowering previous upper limits and suggesting that magnetar formation within dynamical clusters is less efficient than previously assumed.

Chip-firing is a combinatorial game played on an undirected graph in which we place chips on vertices and disperse them. We study chip-firing on an infinite binary tree in which we add a self-loop to the root to ensure each vertex has degree 3. A vertex can fire if the number of chips placed on it is at least its degree. In our case, a vertex can fire if it has at least three chips, and it fires by dispersing one chip to each neighbor. Motivated by a 2023 paper by Musiker and Nguyen on this setting of chip-firing, we give an upper bound for the number of stable configurations when we place 2^ℓ - 1 labeled chips at the root. When starting with N chips at the root where N is a positive integer, we determine the number of times each vertex fires when N is not necessarily of the form 2^ℓ - 1 . We also calculate the total number of fires in this case.

Date Presented 04/03/2025 Understanding triggers and consequences related to substance use after traumatic brain injury (TBI) provides a foundation to facilitate occupational engagement that fosters meaningful daily routines. Study findings support the role of OT on the substance use disorder (SUD) treatment team. Primary Author and Speaker: Amanda Acord-Vira Additional Authors and Speakers: Cecelia Napier, SueAnn Woods, Steven Wheeler Contributing Authors: Cortland Nesley, Jeremy Dixon, kaleigh papez, Nijeul Sharp

Extensive literature has established equivalent efficacy of early intravenous (IV) to oral antibiotic transition. However, there is variability in adoption across practice settings. Unlike Outpatient Parenteral Antimicrobial Therapy (OPAT) programs, Complex Outpatient Antimicrobial Therapy with Oral Agents (COpAT) programs face significant implementation science challenges. We used a clinical trial with broad enrollment criteria to determine impact of early oral transition in a real-world setting and studied its influence on practice transformation. C omparing Oral vs. Parenteral Antimicrobial Therapy (COPAT) Trial was a pragmatic, randomized controlled trial at five hospitals in one rural health system. Patients requiring two or more weeks of IV antibiotics (for all but central nervous system infections) were randomized 2:1 to Experimental (early oral) vs. Control (IV-only). Two primary outcomes and hypotheses were assessed at three months: early oral group safety superiority and efficacy equivalence. Clinical cases of patients who completed the trial were presented at multiple forums. The trial was stopped early after two-thirds enrollment for a significant safety benefit. Early oral group demonstrated a significantly lower adverse event rate (3.2% vs. 6.5%, p= 0.02). Lower cumulative hazard for first study related adverse event in early oral group (HR 0.24, 95% CI 0.08-0.75, p= 0.01) appeared to emerge by day 10. Therapeutic efficacy was equivalent. Cumulative enrollment in the trial had a significant association with COpAT:OPAT program consult ratio (R2= 0.54, p< 0.001). Early oral antibiotic transition was significantly safer. At our academic health system, implementation of the COPAT Trial accelerated practice transformation.