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Linear bounds for the lengths of geodesics on manifolds with curvature bounded below
No full textThis is an open access article under the CC BY license.Let M be a simply connected Riemannian manifold in Mk,vD(n), the space of closed Riemannian manifolds of dimension n with sectional curvature bounded below by k, volume bounded below by v, and diameter bounded above by D. Let c be the smallest positive real number such that any closed curve of length at most 2d can be contracted to a point over curves of length at most cd, where d is the diameter of M. In this paper, we show that under these hypotheses there exists a computable rational function, G(n, k, v, D), such that any continuous map of Sl to Ωp,qM, the space of piecewise differentiable curves on M connecting p and q, is homotopic to a map whose image consists of curves of length at most exp(cexp(G(n,k,v,D))). In particular, for any points p,q∈M and any integer m>0, there exist at least m geodesics connecting p and q of length at most mexp(cexp(G(n,k,v,D))). © Mathematica Josephina, Inc. 2025.Universidad Nacional Autónoma de México, UNAM; Consejo Nacional de Humanidades, Ciencias y Tecnologías; Natural Sciences and Engineering Research Council of Canada, CRSNG; Simons Laufer Mathematical Sciences Institute, University of California Berkeley, SLMath; Hausdorff Research Institute for Mathematics, HIM; Banff International Research Station Casa Matemática Oaxaca, (19w5115); National Security Agency, NSA, (H98230-22-1-0018); National Security Agency, NSA; Simons Foundation, SF, (SFI-MPS-SFM-00006548); Simons Foundation, SF; National Science Foundation, NSF, (DMS-1906404, DMS-2204324, DMS-1928930); National Science Foundation, NSFThe authors would like to thank Hannah Alpert and Megan Kerr for many helpful conversations. They would also like to thank the referee for a careful reading of the paper and helpful suggestions for improvement. They are also grateful to the Banff International Research Station Casa Matem\u00E1tica Oaxaca for its support during the Women in Geometry 2 Workshop (19w5115), where the work on this paper was begun. This article is based upon work supported by the National Science Foundation under Grant No. DMS-1928930 and the National Security Agency under Grant No. H98230-22-1-0018 while the authors participated in a program hosted by the Mathematical Sciences Research Institute in Berkeley, California, during the summer of 2022. The authors also gratefully acknowledge support from the Princeton IAS Summer Collaborators program in 2024, where the bulk of the work on this project was completed. This material is based upon work supported by the National Science Foundation under Grant No. DMS-1928930, while Beach, Rotman, and Searle were in residence at the Simons Laufer Mathematical Sciences Institute (formerly MSRI) in Berkeley, California, during the Fall 2024 semester. The finishing touches to the paper were made during Rotman\u2019s participation in the Trimester Program in Metric Analysis at the Hausdorff Research Institute for Mathematics (HIM). She would like to thank HIM for its hospitality. Beach was supported in part by an NSERC Canada Graduate Scholarships Doctoral grant. Contreras Peruyero was partially supported by the UNAM Postdoctoral Program (POSDOC) and CONACyT Research Grant Ciencia de Frontera 2019 CF 217392. Rotman was partially supported by an NSERC Discovery Grant. Searle was partially supported by NSF Grants DMS-1906404 and DMS-2204324. Part of this paper was written during the third author\u2019s sabbatical leave, during which she was partially supported by The Simons Foundation International Award SFI-MPS-SFM-00006548
11.12 Use of University Campus for Free Expression Activities and Comparison Chart, February 24, 2025
No full textLatinos’ intimate partner violence, abuse, and interventions: Developing a LatCrit analysis and critique
No full textImpact statement: Critical race theory can help us understand how prejudice against people of color may affect the kinds of research questions scientists ask about social problems experienced by people of color, such as intimate partner violence. Our analysis of research on intimate partner violence involving Latino males shows that researchers most commonly study possible causes within individuals rather than the cultural, social, and historical contexts in which Latino families exist. Attending to positive aspects of Latino identity and culture in IPV research would reduce blame and stigma against Latino communities. (PsycInfo Database Record (c) 2025 APA, all rights reserved)The accepted manuscript version of this article will be publicly available on 07/25/2025The article utilizes Latino critical theory and critical psychology perspectives to review and critique the literature on Latinos’ intimate partner violence and abuse and intervention programs. Critical Latino theories are described and reviewed and then applied to the literature on intimate partner violence (IPV) predictors among Latinos. The review demonstrates that the research literature on the predictors, correlates, and antecedents of Latino males’ IPV behaviors focuses largely on the individual level of analysis and consequently suffers from three main limitations: use of deficit models in research, decontextualized assessment and evaluations of IPV, and neglect of higher levels of analysis influencing IPV in Latinx communities. Implications for ending the stigmatization and demonization of Latinos and Latinx culture in research and intervention design on IPV are discussed, with a particular focus on improving the relevance and effectiveness of preventive intervention programs for Latinos. (PsycInfo Database Record (c) 2025 APA, all rights reserved
Sound absorption in uniform and layered gyroid and diamond triply periodic minimal surface porous absorbers
No full textClick on the DOI link to access this article at the publishers website (may not be free).We investigate the acoustical properties of additively manufactured porous absorbers with gyroid and diamond triply periodic minimal surface pore geometries. Porous samples with different relative densities are fabricated using vat photopolymerization and tested using acoustic impedance and airflow resistivity measurement setups. Optical microscopy shows that the increased wall thicknesses due to polymer expansion causes the actual relative densities of the fabricated samples to exceed the intended designs. The two-microphone tests demonstrate that higher relative densities enhance sound absorption effectiveness, with the diamond geometry outperforming the gyroid at equivalent relative densities. The airflow resistivity tests indicate that the superior performance of the diamond samples stems from their increased airflow resistance, attributable to the absence of through-holes in their structure. We use the inverse characterization approach to model the absorbers using the Johnson-Champoux-Allard rigid formulation, uncovering additional variations in bulk transport properties that are linked to the differing geometries. The validated numerical models are then used to predict the sound absorption performance of sound package designs with various series and parallel relative density gradients using a transfer matrix method. Our results show that such layered configurations of additively manufactured TPMS-based absorbers can enable the design of sound packages with application-specific absorption performance. © 2025 Elsevier Lt
Alternative reporting options across the United States: Documenting each state’s options for sexual assault kit collection without a police report
No full textThis is an open access article under the CC BY license.Introduction: The Violence Against Women Act requires that sexual assault victims be able to have a sexual assault kit (SAK) collected without reporting the assault to police, but the details of this “non-report SAK” option vary from state to state. The goal of this study was to analyze non-report SAK policies across the United States. Methods: Information about each state’s policy was collected from 80 practitioners from January 2024 to June 2024. A descriptive policy analysis was conducted, with specific focus on each state’s available options, age of access, forensic testing policies, storage location and timeframe, availability of free medical only exams, and crime victim’s compensation eligibility. Results: All but one state has a formalized non-report SAK option, with six states offering multiple options. Eleven states grant minors access to these options in at least some circumstances. Four states require and five states provide optional forensic testing for non-report SAKs. Law enforcement agencies were the most common storage location, with storage timelines ranging from 90 days to 75 years (M = 17.01 years, SD = 19.05 years). Twenty states offer a free medical exam without forensic evidence collection and 22 have extended victim’s compensation fund eligibility to victims who have a non-report SAK collected. Conclusions: Non-report SAK policies vary widely across the United States, with victims in some states having many more options than in others. Policy Implications: Policymakers should consider expanding the options available to non-reporting victims in states with few options available. Failing to offer free medical only exams, in particular, may have downstream consequences for victims and help-seeking systems. © The Author(s) 2025
A mathematical framework for optimizing immuno-radiotherapy treatments
No full textPresented to the 21st Annual Symposium on Graduate Research and Scholarly Projects (GRASP) held at the Rhatigan Student Center, Wichita State University, April 11, 2025.Research completed in the Department of Industrial, Systems and Manufacturing Engineering, College of Engineering.Immunotherapy (IT) has recently emerged as an important modality for the treatment of advanced-stage cancers. Despite the encouraging clinical results, the number of patients who durably respond to IT alone is small. Therefore, there has been clinical interest in combining IT with other cancer treatment modalities, particularly radiotherapy (RT). The combination of IT and RT, known as immunoradiotherapy (IRT), has shown great clinical promise to induce both local and systemic anti-tumor immune response, leading to a durable disease control. However, RT may also promote immune suppression by killing highly radiosensitive immune cells. The immune stimulant and suppressive effects of RT depend on the timing and dose of radiation and the immunotherapeutic agent.
The primary goal of this research is to develop a mathematical model that captures the interplay between RT and IT by modeling the interactions between tumor cells and immune cells under the influence of radiation and immune checkpoint inhibitors (ICI's). Mathematical modeling of IRT can play a significant role in hypothesis generation for the design of promising clinical trials with the ultimate goal of improving the treatment efficacy for cancer patients.
A compartmental model is developed to simulate the population dynamics of tumor and immune cells. The proposed compartmental model accounts for primary and inactivated tumor cells, metastatic tumor cells and recruited lymphocytes. The model is incorporated into an optimization framework to determine the best IRT treatment schedule. A Monte-Carlo (MC) simulation approach is employed to account for parameter uncertainties in the model. Computational results focus on advanced-stage non-small cell lung cancer (NSCLC), which is commonly treated by IRT. In particular, to estimate the model parameters, the progression-free and overall survival curves obtained from the MC approach are fitted to the Kaplan-Meier survival curves reported from IRT clinical trials for NSCLC. The calibrated model is then used to design an IRT treatment regimen by optimizing the time-averaged progression-free survival for a patient cohort.Graduate School, Academic Affairs, University Librarie
Experimental and computational analysis of laser sintered three-dimensional wick structures for thermal management applications
No full textThesis (Ph.D.)-- Wichita State University, College of Engineering, Dept. of Mechanical EngineeringThe ability to transfer heat over long distances with a small temperature gradient is a highly coveted feature in thermal management and cooling applications for electronics. Heat pipes consisting of wick structures play a vital role in these applications since wicks provide the necessary capillary action to transport the working fluid (such as water or ammonia) from the heat source to the heat sink. The fluid absorbs heat from the source, evaporates into vapor and travels to the condenser (cooler) section of the heat pipe, where it condenses back into liquid, and gets diverted back to the evaporator section to restart the heat transfer loop. For the purposes of this work, two types of wick structures – one manufactured with copper particles and the other with stainless-steel 316L particles - are considered. Existing manufacturing capabilities pose significant barriers in terms of manufacturing time and wastes, to the creation of wick structures for efficient heat transfer. This work examines the feasibility of a novel manufacturing technique for developing microscale porous metallic structures using a pulsed microsecond carbon dioxide (CO2) laser. The preliminary results show the successful fabrication of a sintered copper powder structure at a pulse period of 1000 μs, pulse width of 180 μs. The main benefit of this new manufacturing process is that it provides a significant reduction in manufacturing time –it was observed to be approximately 4.5 hours compared to 18-24 hours in conventional sintering process that these experiments were observed against. The obtained results provide a crucial step toward developing a proof of concept for a new class of manufacturing process for porous metallic structures
