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 (⟨B⟩ = 9 T). 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 (|Ibootstrap| ∼ 2 kA). Calculations of collisional alpha particle confinement in a DT FPP scenario show small energy losses to the first wall (< 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 Pfus = 800 MW operating point is attainable with high fusion gain (Q = 40) at volume-averaged electron densities ne ≈ 2×1020 m−3, below the Sudo density limit. Additional transport calculations show that an ignited (Q = ∞) solution is available at slightly higher density (2.2×1020 m−3) with Pfus = 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 ∼ 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 (FPP) 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 (DCLL), 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 3-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 x 1018 n/cm2 per fullpower 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 grams) and a required TBR (TBRreq) 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 is still required, at the physics basis stage all initial targets have been met for the Infinity Two configuration.

Certain assumptions and procedures basic to factor analysis are examined from the point of view of the mathematician. It is demonstrated that the Hotelling method does not yield meaningful traits, and an example from the theory of gas mixtures with convertible components is cited as evidence. The justification of current methods for determining the adequacy of the reproduction of a correlation matrix by a factorial matrix is questioned, and a x2 criterion, practical only for a small matrix, is proposed. By means of a hypothetical example from geometry, it is shown that results of a Hotelling analysis are necessarily relative to the population at hand. The factorial effects of the adjunction of a “total test” to a group of tests are considered. Some of the general considerations and questions raised are pertinent to types of analysis other than the Hotelling.

Next generation high-power laser facilities are expected to generate hundreds-of-MeV proton beams and operate at multi-Hz repetition rates, presenting opportunities for medical, industrial and scientific applications requiring bright pulses of energetic ions. Characterizing the spectro-spatial profile of these ions at high repetition rates in the harsh radiation environments created by laser–plasma interactions remains challenging but is paramount for further source development. To address this, we present a compact scintillating fiber imaging spectrometer based on the tomographic reconstruction of proton energy deposition in a layered fiber array. Modeling indicates that spatial resolution of approximately 1 mm and energy resolution of less than 10% at proton energies of more than 20 MeV are readily achievable with existing 100 μm diameter fibers. Measurements with a prototype beam-profile monitor using 500 μm fibers demonstrate active readouts with invulnerability to electromagnetic pulses, and less than 100 Gy sensitivity. The performance of the full instrument concept is explored with Monte Carlo simulations, accurately reconstructing a proton beam with a multiple-component spectro-spatial profile.

In a prospective, remote natural history study of 277 individuals with (60) and genetically at risk for (217) Parkinson’s disease (PD), we examined interest in the return of individual research results (IRRs) and compared characteristics of those who opted for versus against the return of IRRs. Most (n = 180, 65%) requested sharing of IRRs with either a primary care provider, neurologist, or themselves. Among individuals without PD, those who requested sharing of IRRs with a clinician reported more motor symptoms than those who did not request any sharing (mean (SD) 2.2 (4.0) versus 0.7 (1.5)). Participant interest in the return of IRRs is strong.

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.

This essay reviews the following works:

The Frontier Effect: State Formation and Violence in Colombia. By Teo Ballvé. Ithaca, NY: Cornell University Press, 2020. Pp. 228. $27.95 paperback. ISBN: 9781501747540.

Paramilitarismo. Balance de la contribución del CNMH al esclarecimiento histórico. By Centro Nacional de Memoria Histórica (CNMH). Bogotá: Centro Nacional de Memoria Histórica, 2018. Pp. 234. Free e-book. ISBN: 9789585500051.

Agrarian Capitalism, War and Peace in Colombia: Beyond Dispossession. By Jacobo Grajales. New York: Routledge, 2021. Pp. 190. $44.95 paperback. ISBN: 978036775707.

Clientelistic Warfare: Paramilitaries and the State in Colombia (1982-2007). By Francisco Gutiérrez Sanín. Oxford: Peter Lang, 2019. Pp. 480 pages. $72.95 hardcover. ISBN: 9781787073654.

Borderland Battles: Violence, Crime, and Governance at the Edges of Colombia’s War. By Annette Idler. New York: Oxford University Press, 2019. Pp. 496. $29.00 paper. ISBN: 9780190849153.

Organized Violence after Civil War: The Geography of Recruitment in Latin America. By Sarah Zukerman Daly. New York: Cambridge University Press, 2016. Pp. 344. $25.00 paperback. ISBN: 9781107566835.

Clinical outcomes of repetitive transcranial magnetic stimulation (rTMS) for treatment of treatment-resistant depression (TRD) vary widely and there is no mood rating scale that is standard for assessing rTMS outcome. It remains unclear whether TMS is as efficacious in older adults with late-life depression (LLD) compared to younger adults with major depressive disorder (MDD). This study examined the effect of age on outcomes of rTMS treatment of adults with TRD. Self-report and observer mood ratings were measured weekly in 687 subjects ages 16–100 years undergoing rTMS treatment using the Inventory of Depressive Symptomatology 30-item Self-Report (IDS-SR), Patient Health Questionnaire 9-item (PHQ), Profile of Mood States 30-item, and Hamilton Depression Rating Scale 17-item (HDRS). All rating scales detected significant improvement with treatment; response and remission rates varied by scale but not by age (response/remission ≥ 60: 38%–57%/25%–33%; <60: 32%–49%/18%–25%). Proportional hazards models showed early improvement predicted later improvement across ages, though early improvements in PHQ and HDRS were more predictive of remission in those < 60 years (relative to those ≥ 60) and greater baseline IDS burden was more predictive of non-remission in those ≥ 60 years (relative to those < 60). These results indicate there is no significant effect of age on treatment outcomes in rTMS for TRD, though rating instruments may differ in assessment of symptom burden between younger and older adults during treatment.

Ammonium-saponite is hydrothermally grown at temperatures below 300°C from a gel with an overall composition corresponding to (NH4)0.6Mg3Al0.6Si3.4O10(OH)2. Using 27Al and 29Si solid-state Magic Angle Spinning NMR techniques it is demonstrated that synthetic ammonium-saponites have a rather constant Si/AlIV ratio (≈ 5.5) and an AlIV/AlVI ratio that varies between 1.5 and 3.8. The above ratios are independent of the synthesis temperature, although an increasing amount of Si, N, and, to a lesser extent, Al are incorporated in an amorphous phase with increasing temperature. 27Al MAS-NMR is unable to differentiate between Al at octahedral and Al3+ at interlayer sites. CEC, XRD, and the inability to swell prove the AlVI to be mainly on the interlayer sites. Based on the NH4- exchange capacity, X-ray fluorescence, 27Al and 29Si MAS-NMR, it is possible to calculate a relatively accurate structural formula.