Rice University Research Repository
The Rice Research Repository (R-3) provides access to research produced at Rice University, including theses and dissertations, journal articles, research center publications, datasets, and academic journals. Managed by Fondren Library, R-3 is indexed by Google and Google Scholar, follows best practices for preservation, and provides DOIs to facilitate citation. Woodson Research Center collections, including Rice Images and Documents and the Task Force on Slavery, Segregation, and Racial Injustice, have moved here.
Communities
Recent Submissions
Changes in the Immigrant Population of the United States in 2025
(Rice University Kinder Institute for Urban Research, 2026) Thomas, Kevin J.A.; Goolsby, Karen P.; Petroff, Thomas A.
The U.S. immigrant population changed significantly between June 2024 and July 2025. The Pew Research Center estimates the total foreign-born population increased to 53.3 million in January 2025, before falling by more than 1 million by June 2025, marking the first sustained national decline in the number of immigrants since the 1960s. Although the decline coincided with the start of the second Trump administration in January 2025, few studies have examined whether it extended beyond June of that year. The overall immigrant population includes both authorized and unauthorized immigrants. Authorized immigrants grew steadily to 37.8 million in 2023, driven by a rapid increase in naturalized citizens. In contrast, the number of unauthorized immigrants rose sharply after the pandemic. The Pew Research Center estimates that the unauthorized immigrant population increased from 10.5 million in 2021 to 11 million in 2022, and then to a record 14 million by mid-2023, with most of the two-year increase attributed to immigrants born outside of Mexico and new arrivals benefiting from temporary protections. These shifts have altered the composition and geographic distribution of unauthorized immigrants. Long-term declines in the Mexican-born unauthorized population—from a peak of about 6.9 million in 2007 to around 4.0 million in 2022—have coincided with rapid growth among immigrants from South America, Central America, and the Caribbean. The six states with the largest unauthorized populations in 2023—California, Texas, Florida, New York, New Jersey, and Illinois—still together host most of these immigrants, but their share has fallen over time as unauthorized immigrants have dispersed to a broader set of states.
Changes in the Immigrant Population of Houston in 2025
(Rice University Kinder Institute for Urban Research, 2026) Thomas, Kevin J.A.; Goolsby, Karen P.; Petroff, Thomas A.
Evidence indicates that the number of immigrants in the United States declined in the first half of 2025. However, it is not clear whether there were corresponding changes in Houston during this period. This uncertainty is critical because immigrants play a central role in shaping the demographic, economic, and social landscape of the city in recent years, accounting for nearly 2 million residents in 2024, or 1 out of every 4 residents in the metropolitan area. These population dynamics are especially relevant for local policymakers and planners because the immigrant population can influence the size of the workforce available across critical sectors, affect municipal tax bases, and alter demand for public services such as education, transportation, and health care. As a result, understanding recent changes in Houston’s immigrant population is essential for anticipating near- and long-term planning needs related to economic development, infrastructure investment, and service provision.
Caging in time: A framework for robust object manipulation under uncertainties and limited robot perception
(Sage, 2025) Wang, Gaotian; Ren, Kejia; Morgan, Andrew S.; Hang, Kaiyu
Real-world object manipulation has been commonly challenged by physical uncertainties and perception limitations. Being an effective strategy, while caging configuration-based manipulation frameworks have successfully provided robust solutions, they are not broadly applicable due to their strict requirements on the availability of multiple robots, widely distributed contacts, or specific geometries of robots or objects. Building upon previous sensorless manipulation ideas and uncertainty handling approaches, this work proposes a novel framework termed Caging in Time to allow caging configurations to be formed even with one robot engaged in a task. This concept leverages the insight that while caging requires constraining the object’s motion, only part of the cage actively contacts the object at any moment. As such, by strategically switching the end-effector configuration and collapsing it in time, we form a cage with its necessary portion active whenever needed. We instantiate our approach on challenging quasi-static and dynamic manipulation tasks, showing that Caging in Time can be achieved in general cage formulations including geometry-based and energy-based cages. With extensive experiments, we show robust and accurate manipulation, in an open-loop manner, without requiring detailed knowledge of the object geometry or physical properties, or real-time accurate feedback on the manipulation states. In addition to being an effective and robust open-loop manipulation solution, Caging in Time can be a supplementary strategy to other manipulation systems affected by uncertain or limited robot perception.
Hemin-induced transient senescence via DNA damage response: a neuroprotective mechanism against ferroptosis in intracerebral hemorrhage
(Springer Nature, 2025) Malojirao, Vikas H.; Vasquez, Velmarini; Kodavati, Manohar; Mitra, Joy; Provasek, Vincent; Voh, Anh Tran Tram; Liopo, Anton V.; Derry, Paul J.; Mikheev, Andrei M.; Rostomily, Robert C.; Horner, Philip J.; Tour, James M.; Britz, Gavin W.; Kent, Thomas A.; Hegde, Muralidhar L.
Intracerebral hemorrhage (ICH) poses acute fatality and long-term neurological risks, in part due to hemin and iron accumulation from hemoglobin breakdown. We observed that hemin induces DNA double-strand breaks (DSBs), prompting a senescence-like phenotype in neurons, necessitating a deeper exploration of cellular responses. Using experimental ICH models and human ICH patient tissue, we elucidate hemin-mediated DNA damage response (DDR) inducing transient senescence and delayed expression of heme oxygenase (HO-1). HO-1 co-localizes with senescence-associated β-Galactosidase (SA-β-Gal) in ICH patient tissues, emphasizing the clinical relevance of inducible HO-1 expression in senescent cells. We reveal a reversible senescence state protective against acute cell death by hemin, while repeat exposure leads to long-lasting senescence. Inhibiting early senescence expression increases cell death, supporting the protective role of senescence against hemin toxicity. Hemin-induced senescence is attenuated by a pleiotropic carbon nanoparticle that is a catalytic mimic of superoxide dismutase, but this treatment increased lipid peroxidation, consistent with ferroptosis from hemin breakdown released iron. When coupled with iron chelator deferoxamine (DEF), the nanoparticle reduces hemin-induced senescence and upregulates factors protecting against ferroptosis. Our study suggests transient senescence induced by DDR as an early potential neuroprotective mechanism in ICH, but the risk of iron-related toxicity supports a multi-pronged therapeutic approach.
The continuous actuation of liquid metal with a 3D-printed electrowetting device
(Springer Nature, 2025) Ghosh, Samannoy; Neupane, Rajan; Sahu, Dwipak Prasad; Teng, Jian; Kong, Yong Lin
The ability of liquid metals (LMs) to recover from repeated stretching and deformation is a particularly attractive attribute for soft bioelectronics. In addition to their high electrical and thermal conductivity, LMs can be actuated, potentially enabling highly durable electro-mechanical and microfluidics systems for applications such as cooling, drug delivery, or reconfigurable electronics. In particular, continuous electrowetting (CEW) phenomena can actuate liquid metal at relatively low voltage and affordable power requirements for wearable systems (~ < 10 V, ~ 10 – 100 µW) by inducing a surface tension gradient across the LM. However, sustaining LM actuation remains challenging due to factors such as electrolyte depletion, polarity changes in multi-electrode systems, and limitations related to LM composition. Here, we demonstrate LM actuation in a circular conduit for prolonged durations of at least nine hours. We enabled sustained actuation by sequentially applying short, direct current (DC) pulses through a multi-electrode system based on the dynamics of LM actuation. As a proof of concept, we also demonstrated the ability of LM to transport electrically conducting, non-conducting, and magnetic materials within a microchannel and show the liquid metal actuation system can be potentially miniaturized to the size of a wearable device. We envision that with further miniaturization of the device architectures, our CEW platform can enable future integration of low-voltage electro-mechanical systems into a broad range of wearable form factors.