We provide an assessment of the Infinity Two fusion pilot plant (FPP) baseline plasma physics design. Infinity Two is a four-field period, aspect ratio $A = 10$, quasi-isodynamic stellarator with improved confinement appealing to a max-$J$ approach, elevated plasma density and high magnetic fields ($ \langle B\rangle = 9$ T). Here $J$ denotes the second adiabatic invariant. At the envisioned operating point ($800$ MW deuterium-tritium (DT) fusion), the configuration has robust magnetic surfaces based on magnetohydrodynamic (MHD) equilibrium calculations and is stable to both local and global MHD instabilities. The configuration has excellent confinement properties with small neoclassical transport and low bootstrap current ($|I_{bootstrap}| \sim 2$ kA). Calculations of collisional alpha-particle confinement in a DT FPP scenario show small energy losses to the first wall (${\lt}1.5 \,\%$) and stable energetic particle/Alfvén eigenmodes at high ion density. Low turbulent transport is produced using a combination of density profile control consistent with pellet fueling and reduced stiffness to turbulent transport via three-dimensional shaping. Transport simulations with the T3D-GX-SFINCS code suite with self-consistent turbulent and neoclassical transport predict that the DT fusion power$P_{{fus}}=800$ MW operating point is attainable with high fusion gain ($Q=40$) at volume-averaged electron densities $n_e\approx 2 \times 10^{20}$ m$^{-3}$, below the Sudo density limit. Additional transport calculations show that an ignited ($Q=\infty$) solution is available at slightly higher density ($2.2 \times 10^{20}$ m$^{-3}$) with $P_{{fus}}=1.5$ GW. The magnetic configuration is defined by a magnetic coil set with sufficient room for an island divertor, shielding and blanket solutions with tritium breeding ratios (TBR) above unity. An optimistic estimate for the gas-cooled solid breeder designed helium-cooled pebble bed is TBR $\sim 1.3$. Infinity Two satisfies the physics requirements of a stellarator fusion pilot plant.

The selection, design and optimization of a suitable blanket configuration for an advanced high-field stellarator concept is seen as a key feasibility issue and has been incorporated as a vital and necessary part of the Infinity Two fusion pilot plant physics basis. The focus of this work was to identify a baseline blanket which can be rapidly deployed for Infinity Two while also maintaining flexibility and opportunities for higher performing concepts later in development. Results from this analysis indicate that gas-cooled solid breeder designs such as the helium-cooled pebble bed (HCPB) are the most promising concepts, primarily motivated by the neutronics performance at applicable blanket build depths, and the relatively mature technology basis. The lithium lead (PbLi) family of concepts, particularly the dual-cooled lithium lead, offer a compelling alternative to solid blanket concepts as they have synergistic developmental pathways while simultaneously mitigating much of the technical risk of those designs. Homogenized three-dimensional neutronics analysis of the Infinity Two configuration indicates that the HCPB achieves an adequate tritium breeding ratio (TBR) (1.30 which enables sufficient margin at low engineering fidelity), and near appropriate shielding of the magnets (average fast fluence of 1.3 ${\times}$ 10$^{18}$ n cm$^{-2}$ per full-power year). The thermal analysis indicates that reasonably high thermal efficiencies (greater than 30 %) are readily achievable with the HCPB paired with a simple Rankine cycle using reheat. Finally, the tritium fuel cycle analysis for Infinity Two shows viability, with anticipated operational inventories of less than one kilogram (approximately 675 g) and a required TBR (TBR$_{\textrm {req}}$) of less than 1.05 to maintain fuel self-sufficiency (approximately 1.023 for a driver blanket with no inventory doubling). Although further optimization and engineering design are still required, at the physics basis stage all initial targets have been met for the Infinity Two configuration.

Transfers of resources in dictator games vary significantly by the characteristics of recipients. We focus on social norms and demonstrate that variation in the recipient changes both giving and injunctive norms and may offer an explanation for differences in giving. We elicit generosity using dictator games, and social norms using incentivized coordination games, with two different recipient types: an anonymous student and a charitable organization. A within-subjects design ensures that other factors are held constant. Our results show that differences in giving behavior are closely related to differences in social norms of giving across contexts. Controlling for individual differences in beliefs about the norm, subjects do not weight compliance with the norms in the student recipient or charity recipient dictator game differently. These results suggest that the impact of context on giving co-occurs with an impact on social norms.

We investigate cooperation using an incremental investment game in which the first-mover has the ability to make small, but increasing incremental investments in their counterpart. Our experiment is designed to test whether establishing trust in small increments is more effective than alternatives, including a one-shot investment game, a decrease only condition where the amount the first-mover sends to the second-mover must be less than the amount previously sent, and an unrestricted condition where the first-mover is not restricted by the amount previously sent. Although results were mixed, broadly, iteration affords greater cooperation than one-shot games and, when given the choice, participants seem to prefer to build trust gradually. Implications for institutional design are discussed.

We report a pair of simple polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assays based on two independently segregating nuclear genes that can differentiate the North American native [Phragmites australis (Cav.) Trin. ex Steud. ssp. americanus Saltonst., P.M. Peterson & Soreng] from other lineages. Because nuclear markers are inherited biparentally, researchers can also use them to screen for F1 hybrids between P. australis ssp. americanus and the other lineages. We show that a previously described assay based on an indel in the nuclear gene NRT2 consistently identifies a wide range of P. australis ssp. americanus haplotypes and distinguishes them from the Gulf Coast type [Phragmites australis (Cav.) Trin. ex Steud. ssp. berlandieri (E. Fourn.) Saltonst. & Hauber]. We also demonstrate a new PCR-RFLP assay for a previously described diagnostic single-nucleotide polymorphism adjacent to the PaGT4 microsatellite marker that also distinguishes P. australis ssp. americanus from the other lineages. In addition, we report the first case of Asian haplotype AS identified in North America and make recommendations for its detection. Our findings expand the tools available to those monitoring for invasion by introduced Phragmites in North America.

Background: Sex and gender are related but distinct determinants of disease, treatment response, and research reproducibility whose consideration is increasingly required for research funding. Nevertheless, the quality of sex and gender reporting in neurological randomized controlled trials (RCTs) remains unknown. Methods: This ongoing study of RCTs associated with Food and Drug Administration neurological drug approvals aims to determine the frequency of accurate reporting of RCT participants’ sex and gender. Secondary outcomes include changes in reporting over time and RCT design characteristics. Results: Preliminary analysis included 145 RCTs (153,410 participants) associated with 77 medications approved in 1985-2023, most commonly for epilepsy (19%), migraine (16%), and multiple sclerosis (16%). Sixty-six RCTs (45.5%) used sex-related terms appropriately. Nine RCTs (6.2%) reported gender accurately. Fifty-three RCTs (37%) used sex- or gender-related terms interchangeably. There are no statistically significant differences in the proportions of studies reporting sex and/or gender accurately when comparing those published until versus after 2017. No RCT reported sex or gender collection methods, definitions of sex or gender, or including sex or gender minority participants. Conclusions: Preliminary results suggest shortcomings in reporting sex and, especially, gender accurately and inclusively among neurological drug RCTs and no significant improvement thereof in recent years.

OBJECTIVES/GOALS: To evaluate the incidence of brachial plexus birth injury (BPBI) and its associations with maternal demographic factors. Additionally, we sought to determine whether longitudinal changes in BPBI incidence differed by maternal demographics. METHODS/STUDY POPULATION: We conducted a retrospective cohort study of over 8 million maternal-infant pairs using California’s Office of Statewide Health Planning and Development Linked Birth Files from 1991-2012. Descriptive statistics were used to determine BPBI incidence and the prevalence of maternal demographic factors (race, ethnicity, age). Multivariable logistic regression was used to determine associations of year, maternal race, ethnicity, and age with BPBI. Excess population level risk associated with these characteristics was determined by calculating population attributable fractions. RESULTS/ANTICIPATED RESULTS: The incidence of BPBI between 1991-2012 was 1.28 per 1000 live births, with peak incidence of 1.84 per 1000 in 1998 and low of 0.9 per 1000 in 2008. Incidence varied by demographic group, with infants of Black (1.78 per 1000) and Hispanic (1.34 per 1000) mothers having the highest incidences. Controlling for relevant covariates, infants of Black (AOR=1.88, 95% CI 1.70, 2.08), Hispanic (AOR=1.25, 95% CI 1.18, 1.32) and advanced-age mothers (AOR=1.16, 95% CI 1.09, 1.25) were at increased risk. Disparities in risk experienced by Black, Hispanic, and advanced-age mothers contributed to a 5%, 10%, and 2% excess risk at the population level, respectively. Longitudinal trends in incidence did not vary among demographic groups. Population-level changes in maternal demographics did not explain changes in incidence over time. DISCUSSION/SIGNIFICANCE: Although BPBI incidence has decreased in California, demographic disparities exist. Infants of Black, Hispanic, and advanced-age mothers are at increased BPBI risk compared to White, Non-Hispanic, and younger mothers.

OBJECTIVES/GOALS: To evaluate the association of maternal delivery history with a brachial plexus birth injury (BPBI) risk in subsequent deliveries, and to estimate the effect of subsequent delivery method on BPBI risk. METHODS/STUDY POPULATION: We conducted a retrospective cohort study of all livebirth deliveries occurring in California-licensed hospitals from 1996-2012. The primary outcome was recurrent BPBI in a subsequent pregnancy. The exposure was prior delivery history (parity, shoulder dystocia in a previous delivery, or previously delivering an infant with BPBI). Multiple logistic regression was used to model adjusted associations of prior delivery history with BPBI in a subsequent pregnancy. The adjusted risk (AR) and adjusted risk difference (ARD) for BPBI between vaginal and cesarean delivery in subsequent pregnancies were determined, stratified by prior delivery history, and the number of cesarean deliveries needed to prevent one BPBI was determined. RESULTS/ANTICIPATED RESULTS: Of 6,286,324 infants delivered by 4,104,825 individuals, 7,762 (0.12%) were diagnosed with a BPBI. Higher parity was associated with a 5.7% decrease in BPBI risk with each subsequent delivery (aOR 0.94, 95%CI 0.92, 0.97). Previous shoulder dystocia or BPBI were associated with 5-fold (aOR=5.39, 95%CI 4.10, 7.08) and 17-fold increases (aOR=17.22, 95%CI 13.31, 22.27) in BPBI risk, respectively. Among individuals with a history of delivering an infant with a BPBI , cesarean delivery was associated with a 73.0% decrease in BPBI risk (aOR=0.27, 95%CI 0.13, 0.55), compared with an 87.9% decrease in BPBI risk (aOR=0.12, 95%CI 0.10, 0.15) in individuals without this history. Among individuals with a previous history of BPBI, 48.1 cesarean deliveries are needed to prevent one BPBI. DISCUSSION/SIGNIFICANCE: Parity, previous shoulder dystocia, and previously delivering a BPBI infant are associated with future BPBI risk. These factors are identifiable prenatally and can inform discussions with pregnant individuals regarding BPBI risk and planned mode of delivery.

There is a major debate as to whether there are non-causal mathematical explanations of physical facts that show how the facts under question arise from a degree of mathematical necessity considered stronger than that of contingent causal laws. We focus on Marc Lange’s account of distinctively mathematical explanations to argue that purported mathematical explanations are essentially causal explanations in disguise and are no different from ordinary applications of mathematics. This is because these explanations work not by appealing to what the world must be like as a matter of mathematical necessity but by appealing to various contingent causal facts.

Aviation passenger screening has been used worldwide to mitigate the translocation risk of SARS-CoV-2. We present a model that evaluates factors in screening strategies used in air travel and assess their relative sensitivity and importance in identifying infectious passengers. We use adapted Monte Carlo simulations to produce hypothetical disease timelines for the Omicron variant of SARS-CoV-2 for travelling passengers. Screening strategy factors assessed include having one or two RT-PCR and/or antigen tests prior to departure and/or post-arrival, and quarantine length and compliance upon arrival. One or more post-arrival tests and high quarantine compliance were the most important factors in reducing pathogen translocation. Screening that combines quarantine and post-arrival testing can shorten the length of quarantine for travelers, and variability and mean testing sensitivity in post-arrival RT-PCR and antigen tests decrease and increase with the greater time between the first and second post-arrival test, respectively. This study provides insight into the role various screening strategy factors have in preventing the translocation of infectious diseases and a flexible framework adaptable to other existing or emerging diseases. Such findings may help in public health policy and decision-making in present and future evidence-based practices for passenger screening and pandemic preparedness.

By focusing on peace, Glowacki provides a fresh perspective on warfare. Why did humans evolve peace? Other animals aggregate peacefully when resources are not economically defendable. The human capacity for peace may arise from two key factors: Multilevel societies and psychology shaped by within-group exchanges, which may have begun when tools enabled hominins to extract foods, including tubers and roots.