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We Make Do and We Are Creative: A Report on the Status on Women and Gender Equity Centers
Get PDFThis report covers the experiences of women and gender equity centers in higher education relative to their institutional and national climates.https://commons.case.edu/mathercenter-briefs/1007/thumbnail.jp
Discord in Concordance Cosmology and Anomalously Massive Early Galaxies
Get PDFCosmological parameters are constrained by a wide variety of observations. We examine the concordance diagram for modern measurements of the Hubble constant, the shape parameter from the large-scale structure, the cluster baryon fraction, and the age of the universe, all from non-CMB data. There is good agreement for (Formula presented.) and (Formula presented.). This concordance value is indistinguishable from the WMAP3 cosmology but is not consistent with that of Planck: there is a tension in (Formula presented.) as well as (Formula presented.). These tensions have emerged as progressively higher multipoles have been incorporated into CMB fits. This temporal evolution is suggestive of a systematic effect in the analysis of CMB data at fine angular scales and may be related to the observation of unexpectedly massive galaxies at high redshift. These are overabundant relative to (Formula presented.) CDM predictions by an order of magnitude at (Formula presented.). Such massive objects are anomalous and could cause gravitational lensing of the surface of last scattering in excess of the standard calculation made in CMB fits, potentially skewing the best-fit cosmological parameters and contributing to the Hubble tension
Quantifying 3D MR Fingerprinting (3D-MRF) Reproducibility Across Subjects, Sessions, and Scanners Automatically Using MNI Atlases
Get PDFPurpose: Quantitative MRI techniques such as MR fingerprinting (MRF) promise more objective and comparable measurements of tissue properties at the point-of-care than weighted imaging. However, few direct cross-modal comparisons of MRF\u27s repeatability and reproducibility versus weighted acquisitions have been performed. This work proposes a novel fully automated pipeline for quantitatively comparing cross-modal imaging performance in vivo via atlas-based sampling. Methods: We acquire whole-brain 3D-MRF, turbo spin echo, and MPRAGE sequences three times each on two scanners across 10 subjects, for a total of 60 multimodal datasets. The proposed automated registration and analysis pipeline uses linear and nonlinear registration to align all qualitative and quantitative DICOM stacks to Montreal Neurological Institute (MNI) 152 space, then samples each dataset\u27s native space through transformation inversion to compare performance within atlas regions across subjects, scanners, and repetitions. Results: Voxel values within MRF-derived maps were found to be more repeatable (σT1 = 1.90, σT2 = 3.20) across sessions than vendor-reconstructed MPRAGE (σT1w = 6.04) or turbo spin echo (σT2w = 5.66) images. Additionally, MRF was found to be more reproducible across scanners (σT1 = 2.21, σT2 = 3.89) than either qualitative modality (σT1w = 7.84, σT2w = 7.76). Notably, differences between repeatability and reproducibility of in vivo MRF were insignificant, unlike the weighted images. Conclusion: MRF data from many sessions and scanners can potentially be treated as a single dataset for harmonized analysis or longitudinal comparisons without the additional regularization steps needed for qualitative modalities
Rates of Urinary Tract Infection in Transgender Women Postvaginoplasty vs Cisgender Women: A Retrospective Cohort Study in a Large US Health Network
Get PDFObjective: To describe urinary tract infection (UTI) risk 3-month postvaginoplasty (VP) in transgender women (TW) compared to cis women (CW). Methods: Using TriNetX (TriNetX, Inc, Cambridge, MA), we built cohorts of 2041 TW and 48,374,745 CW. Outcomes were ≥1 instance of UTI or Cystitis, and assessed from 3-6, 3-12, 3-36 months, and 3 months-10 years post-VP. TW and CW were age-cohorted (18-39, 40-59, 60-74) and compared at each time interval. Kaplan-Meier was used to account for loss to follow-up, along with hazard ratios and log-rank tests to determine significance (P \u3c.05). Results: For all time intervals and age ranges, TW had a significantly (P \u3c.0001-P = .0088) higher probability of developing a UTI compared to CW. The largest difference was ages 40-59 ten-year post-VP. In this analysis, CW and TW had a 12.96% and 29.34% cumulative outcome incidence, respectively. Cox proportional hazard analysis demonstrated increased hazard for TW compared to CW. Hazard ratios between CW and TW ranged from 1.363 (ages 18-39 at 10 years, 95%CI: 1.119,1.660) to 3.522 (ages 60-74 at 12 months, 95%CI: 1.951,6.360). Conclusion: We found a significantly higher probability of TW developing UTIs compared to age-cohorted CW. Contributing factors may include difficulties with neovaginal perineal hygiene, lack of commensal bacteria and vaginal mucosa, larger urethral meatus, high rates of meatal stenosis, and nonnative bacteria introduced through dilators and douching. These findings may help improve quality of postoperative care in TW
Effects of Confinement on Opposed-Flow Flame Spread over Cellulose and Polymeric Solids in Microgravity
Get PDFOpposed-flow flame spread over solid materials has been investigated in the past few decades owing to its importance in the fundamental understanding of fires. These studies provided insights into the behavior of opposed-flow flames in different environmental conditions (e.g., flow speed, oxygen concentration). However, the effect of confinement on opposed-flow flames remains under-explored. It is known that confinement plays a critical role in concurrent-flow flame spread in normal and microgravity conditions. Hence, for a complete understanding, it becomes important to understand the effects of confinement for opposed-flow flames. In this study, microgravity experiments are conducted aboard the International Space Station (ISS) to investigate opposed-flow flame spread in different confined conditions. Two materials, cotton-fiberglass blended textile fabric (SIBAL) and 1 mm thick polymethyl methacrylate (PMMA) slab, are burned between a pair of parallel flow baffles in a small flow duct. By varying the sample-baffle distance, various levels of confinement are achieved (H = 1–2 cm). Three types of baffles, transparent, black, and reflective, are used to create different radiative boundary conditions. The purely forced flow speed is also varied (between 2.6 and 10.5 cm/s) to investigate its interplay with the confinement level. For both sample materials, it is observed that the flame spread rate decreases when the confinement level increases (i.e., when H decreases). In addition, the flame spread rate is shown to have a positive correlation with flow speed, up to an optimal value. The results also indicate that the optimal flow speed for flame spread can decrease in highly confined conditions. Surface radiation on the confinement boundary is shown to play a key role. For SIBAL fabric, stronger flames are observed when using black baffles compared to transparent ones. For PMMA, reflective baffles yield stronger flames compared to black baffles. When comparing the results to the concurrent-flow case, it is also noticed that opposed-flow flames spread more slowly and blow off at larger flow speeds, but are not as sensitive to the flow speed. This work provides unique long-duration microgravity experimental data that can inform the design of future opposed-flow experiments in microgravity and the development of theory and numerical models
Navigation by Magnetic Signatures in a Realistic Model of Earth’s Magnetic Field
Get PDFCertain animal species use the Earth’s magnetic field (i.e. magnetoreception) alongside their other sensory modalities to navigate long distances that include continents and oceans. It is hypothesized that several animals use geomagnetic parameters, such as field intensity and inclination, to recognize specific locations or regions, potentially enabling migration without a pre-surveyed map. However, it is unknown how animals use geomagnetic information to generate guidance commands, or where in the world this type of strategy would maximize an animal’s fitness. While animal experiments have been invaluable in advancing this area, the phenomenon is difficult to study in vivo or in situ, especially on the global scale where the spatial layout of the geomagnetic field is not constant. Alongside empirical animal experiments, mathematical modeling and simulation are complementary tools that can be used to investigate animal navigation on a global scale, providing insights that can be informative across a number of species. In this study, we present a model in which a simulated animal (i.e. agent) navigates via an algorithm which determines travel heading based on local and goal magnetic signatures (here, combinations of geomagnetic intensity and inclination) in a realistic model of Earth’s magnetic field. By varying parameters of the navigation algorithm, different regions of the world can be made more or less reliable to navigate. We present a mathematical analysis of the system. Our results show that certain regions can be navigated effectively using this strategy when these parameters are properly tuned, while other regions may require more complex navigational strategies. In a real animal, parameters such as these could be tuned by evolution for successful navigation in the animal’s natural range. These results could also help with developing engineered navigation systems that are less reliant on satellite-based methods
Association between Residential Distance to Airport and Blood Lead Levels in Children under 6 Living in North Carolina, 1992–2015
No full textEven with progress in lead poisoning prevention, research has consistently shown there is no safe blood lead level (BLL) for children.1 Behavioral and cognitive deficits are associated with lead exposure, even at low levels.2 Unfortunately, many piston-engine aircraft are still fueled by leaded aviation gas (avgas). The US Environmental Protection Agency (EPA) estimates that 5.2 million people live within 500m of an airport where avgas is used.3 Our past research in six North Carolina (NC) counties indicates that children living within 500m of airports where avgas is used have ∼4% higher BLLs than children who lived beyond 2,000m (reference group); the association between avgas and children’s BLLs was still detectable at 1,000m. Building on this work, this study investigates the relationship between avgas and BLLs in children across all 100 NC counties. In October 2023, the EPA finalized an endangerment finding as the first step in using its authority to regulate the use of avgas. EPA is now required by the Clean Air Act to propose and promulgate regulatory standards for lead emissions from certain aircraft engines. Moreover, the Federal Aviation Administration (FAA) must propose avgas that will control or eliminate lead emissions. In this paper, we provide evidence that is relevant to the EPA’s future regulatory proposals
Carbon-Sulfur Bond Elongation as the Promoting Reaction Coordinate in the Efficient Sub-Nanosecond Intersystem Crossing in Thianaphthene Derivatives
Get PDFThiophene derivatives have become integral to OLEDs, photovoltaics, and photodynamic therapy research. A deeper understanding of their excited state dynamics and electronic relaxation mechanisms is expected to provide important physical insights of direct relevance for these applications. In this study, thianaphthene (TN), 2-methylbenzothiophene (2MBT), and 3-methylbenzothiophene (3MBT) are investigated using femtosecond broadband transient absorption and steady-state spectroscopy techniques along with time-dependent density functional calculations in cyclohexane and acetonitrile. The photophysical properties and electronic relaxation mechanisms of these derivatives are elucidated. Small fluorescence quantum yields ranging from 0.4 to 1.1% are measured. It is demonstrated that excitation of TN at 290 nm leads primarily to intersystem crossing to the triplet manifold with a lifetime of 400 ± 15 ps in either solvent, whereas four- to twofold shorter intersystem crossing lifetimes are measured for 2MBT and 3MBT depending on whether cyclohexane or acetonitrile is used. Linear interpolation of internal coordinates evidence that elongation of the S-C bonds enables ultrafast intersystem crossing in these thiophene derivatives involving singlet and triplet states with ππ* and πσ* characters. Excitation at 266 nm results in an additional 5 ± 1 ps lifetime, which is assigned to intramolecular vibrational relaxation dynamics occurring in the excited singlet state
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