Measurement is the weak link between theory and empirical test. Complex concepts such as ideology, identity, and legitimacy are difficult to measure; yet, without measurement that matches theoretical constructs, careful empirical studies may not be testing that which they had intended. Item response theory (IRT) models offer promise by producing transparent and improvable measures of latent factors thought to underlie behavior. Unfortunately, those factors have no intrinsic substantive interpretations. Prior solutions to the substantive interpretation problem require exogenous information about the units, such as legislators or survey respondents, which make up the data; limit analysis to one latent factor; and/or are difficult to generalize. We propose and validate a solution, IRT-M, that produces multiple, potentially correlated, generalizable, latent dimensions, each with substantive meaning that the analyst specifies before analysis to match theoretical concepts. We offer an R package and step-by-step instructions in its use, via an application to survey data.

The California Department of Public Health (CDPH) reviewed 109 cases of healthcare personnel (HCP) with laboratory-confirmed mpox to understand transmission risk in healthcare settings. Overall, 90% of HCP with mpox had nonoccupational exposure risk factors. One occupationally acquired case was associated with sharps injury while unroofing a patient’s lesion for diagnostic testing.

Objectives: Few reports have been published about the transmission of mpox in healthcare settings. During the 2022 multinational outbreak, the California Department of Public Health (CDPH) conducted a systematic review of healthcare personnel (HCP) with mpox, including their community and occupational exposures, to understand the transmission risk in healthcare settings. We also sought to inform return-to-work protocols by describing the frequency of HCP working while symptomatic for mpox and identifying occurrences of secondary transmission from infected HCP to patients. Methods: We analyzed surveillance data for laboratory-confirmed mpox cases in California with symptom onset from May 17 to September 30, 2022, collected by investigators at local health departments and reported to the CDPH. The reported data were supplemented by review of free-text variables, interview notes, and other files uploaded to state and county disease surveillance data registries. We identified HCP as all persons working in healthcare settings with potential for direct or indirect exposure to patients or infectious materials, including clinical and nonclinical staff but excluding remote workers. Results: The CDPH received reports of 3,176 mpox cases during the study period: 109 were HCP. Of the 109 HCP identified from 19 counties, 78 (72%) were aged 30–49 years, 102 (94%) were male, and 43 (39%) were Hispanic or Latino. Also, 29 HCP (27%) had received at least 1 dose of the JYNNEOS vaccine. Occupations requiring frequent physical interactions with patients were reported for 66 individuals (61%). During interviews with local health department investigators, nearly all HCP (n = 98, 90%) reported potential or confirmed sources of community exposure; 1 had confirmed occupational exposure with symptom onset 9 days after a sharps injury acquired during collection of an mpox specimen for testing. Of the 60 HCP who provided information about the days they worked, 35 (58%) worked while symptomatic, for a mean of 3.14 days (median, 2; IQR, 3). Also, 2 HCP worked for 12 days after symptom onset. No secondary cases of mpox were associated with HCP reported to the CDPH. Conclusions: This analysis suggests that HCP are more likely to be exposed to mpox in community settings than healthcare settings. The findings support recommendations against sharps use for mpox specimen collection. Although transmission between symptomatic HCP and patients was not reported, HCP can decrease opportunities for mpox transmission by closely monitoring themselves for symptoms after potential exposures and staying home from work if symptoms develop.

Disclosures: None

ABSTRACT IMPACT: This study assesses patient and volumetric risk factors for distant recurrence within 6 months of completion of curative chemoradiation with brachytherapy in locally advanced cervical cancer. OBJECTIVES/GOALS: Initial tumor volume and tumor shrinkage velocity are prognostic of cure and survival after curative chemoradiation (CRT) for cervical cancer. We explored whether local tumor volumetric changes influence time to distant recurrences outside the radiation field. METHODS/STUDY POPULATION: We performed a retrospective cohort study of patients with FIGO Stage IB-IVA cervical cancer treated with curative CRT and brachytherapy at a tertiary academic center with minimum 3 months follow up and standard post-treatment FDG-PET. Patients received 6 weekly fractions of brachytherapy interdigitated with external beam radiation and cisplatin. Tumor volumes were assessed by MRI at brachytherapy planning. Patients who developed distant metastasis were classified as earliest (3-6 months), early (6-24 months) or late (>24 months) following completion of CRT. Absolute and percent decrease in tumor volume for each fraction were calculated with respect to first brachytherapy volume. Fisher’s exact and Mann Whitney-U tests were used for comparison of categorical and continuous variables. RESULTS/ANTICIPATED RESULTS: 143 of 574 (25%) patients developed distant metastasis. Distribution of age, histology, FIGO 2018 stage, primary tumor SUVmax, treatment length, and pre/post treatment squamous cell carcinoma antigen levels were not associated in each group. Para-aortic lymph metastases were more common in patients with earliest distant recurrence (33% earliest, 26% early, 12% late, p=0.03). Median initial tumor volume in the earliest (n=24), early (n =29) and late (n=9) groups was 57, 28 and 40 mL, respectively (p=0.08); 57 (earliest) vs 30mL (early+late groups), p=0.04. Average mid treatment (fraction 4) and end of treatment (fraction 6) percent shrinkage was 80 (earliest) vs 73 (early+late), p=0.84 and 94 vs 92, p=0.95, respectively. Neither absolute nor percent tumor shrinkage differed between early vs. late groups. DISCUSSION/SIGNIFICANCE OF FINDINGS: Tumor volumetric changes during definitive chemoradiation were not associated with the timing of developing distant metastasis, which is linked to presence of lymph node metastasis and tumor volume at diagnosis.

Recent criticism of American legal education has focused on its being theory-driven rather than practice driven, which either produces or reinforces a divide or gap between theory and practice. Yet two features of American legal education expressly draw upon experiential learning, one directly by sending students into experiential learning situations (legal clinics) and the other indirectly by bringing instructors who are engaged full-time in active practice into the classroom (i.e. adjunct faculty). If skills development is a feature of American legal education, to what degree can, or should, this be transplanted to other systems of legal education? Are American experiential techniques of legal education meaningful elsewhere?

A well-posedness theory for the initial-value problem for hydroelastic waves in two spatial dimensions is presented. This problem, which arises in numerous applications, describes the evolution of a thin elastic membrane in a two-dimensional (2D) potential flow. We use a model for the elastic sheet that accounts for bending stresses and membrane tension, but which neglects the mass of the membrane. The analysis is based on a vortex sheet formulation and, following earlier analyses and numerical computations in 2D interfacial flow with surface tension, we use an angle–arclength representation of the problem. We prove short-time well-posedness in Sobolev spaces. The proof is based on energy estimates, and the main challenge is to find a definition of the energy and estimates on high-order non-local terms so that an a priori bound can be obtained.

AlGaN/GaN heterostructures were grown by metal–organic chemical vapor deposition (MOCVD) on sp2-bonded BN using AlN as a nucleation layer. The best x-ray diffraction rocking curve full-width-at-half-maximums (FWHMs) are 0.13° and 0.17° for the GaN (0002) and ( $10\bar 12$ ) diffraction peaks. Hall-effect measurements show room temperature mobility near 2000 cm/V·s with sheet carrier density of ∼1 × 1013 cm−2, comparable to the best values obtained on sapphire using Fe-doped GaN buffers. The best low temperature mobility of the 2-dimensional electron gas (2DEG) is ∼33,000 cm2/V·s; indicating that the dominant scattering mechanism limiting the transport of 2DEG is interface roughness. Good quality BN grown directly onto sapphire is shown to be effective for reducing parallel conduction that exists due to residual donor impurities in the buffer. Luminescence measurements indicate good optical quality of the GaN/BN/sapphire. The residual strain in the GaN layer is found to be almost completely eliminated when it is released from the substrate.

The 2013 Infection Prevention and Control (IP&C) Guideline for Cystic Fibrosis (CF) was commissioned by the CF Foundation as an update of the 2003 Infection Control Guideline for CF. During the past decade, new knowledge and new challenges provided the following rationale to develop updated IP&C strategies for this unique population:

1. The need to integrate relevant recommendations from evidence-based guidelines published since 2003 into IP&C practices for CF. These included guidelines from the Centers for Disease Control and Prevention (CDC)/Healthcare Infection Control Practices Advisory Committee (HICPAC), the World Health Organization (WHO), and key professional societies, including the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). During the past decade, new evidence has led to a renewed emphasis on source containment of potential pathogens and the role played by the contaminated healthcare environment in the transmission of infectious agents. Furthermore, an increased understanding of the importance of the application of implementation science, monitoring adherence, and feedback principles has been shown to increase the effectiveness of IP&C guideline recommendations.

2. Experience with emerging pathogens in the non-CF population has expanded our understanding of droplet transmission of respiratory pathogens and can inform IP&C strategies for CF. These pathogens include severe acute respiratory syndrome coronavirus and the 2009 influenza A H1N1. Lessons learned about preventing transmission of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant gram-negative pathogens in non-CF patient populations also can inform IP&C strategies for CF.