17179 research outputs found
Sort by
Effects of supraseasonal drought on karst aquatic communities of the Edwards Plateau
No full textSupraseasonal droughts refer to an unpredictable period of below average precipitation occurring over multiple seasons and are predicted to become more frequent in central Texas under future climate scenarios. The purpose of this study was to opportunistically assess the effects of a supraseasonal drought (2022 – 2024) on aquatic habitats, mussel assemblage, and fish assemblage within headwater (N = 6 sites), mainstem (N = 10 sites), and tributary (N = 4 sites) reaches of the upper Guadalupe River. At the start of an exceptional drought in 2022 and through 2024, streamflow from spring outflows of karst aquifers were sufficient to provide flowing water habitats in the headwater reaches, upper mainstem, and one of the tributaries. Farther downstream in the mainstem, stream flows became subsurface and reemerged periodically to provide surface waters. All reaches, including the downstream reach with fragmented flows, supported mussels, including federally listed Cyclonaias necki and Lampsilis bergmanni. Likewise, all reaches supported spring-associated fishes and riverine fishes, including several imperiled species, with spring-associated fishes persisting in the headwater reaches between 2022 and 2024. Although exceptional and supraseasonal droughts are typically linked to substantial changes in aquatic communities in more humid regions, lack of detectable changes in aquatic habitats and fish assemblages within a semi-arid region (this study) were attributed to continuous flow of water from karst aquifers and to an aquatic community that has been filtered (e.g., retreating edge hypothesis) via a shift towards a semi-arid climate during Holocene warming.Biolog
A Synopsis of Two Decades of Arthropod Related Research at the Forensic Anthropology Research Facility (FARF), Texas State University (TXST), San Marcos, Texas, USA
No full textThe Forensic Anthropology Research Facility (FARF) at Texas State University (TXST), San Marcos, TX, USA, is a leading human taphonomy facility (HTF), dedicated to advancing forensic science through the study of human decomposition. This systematic review synthesizes 15 scholarly outputs comprising 7 peer-reviewed journal articles and 8 dissertations centered on arthropod-associated research undertaken at FARF, with particular emphasis on its contribution to forensic entomology. The analyzed body of literature is organized into six overarching thematic domains: (1): refining postmortem interval (PMI) estimation; (2): developmental biology of forensic arthropods; (3): arthropod behavior and forensic implications; (4): Taxonomy and systematics; (5): microbial–arthropod interactions; and (6): forensic decomposition scenarios with arthropod involvement. Key contributions from these studies include refined methodologies for PMI estimation, the systematic revision of forensically relevant arthropods and identification of accidental arthropod activity. Additionally, studies at FARF have incorporated interdisciplinary approaches bridging entomology, microbiology and ecology. The semi-arid, subtropical environment and large open natural range of FARF provides some unique regional and specific insights concerning decomposition. This entomological review on FARF is the first to be completed concerning any HTF and adds to the knowledge of forensic evidence involving arthropods.Anthropolog
Regression Analysis of Triply Periodic Minimal Surface (TPMS) Models to Achieve Multi-Objective Optimization
No full textFreshwater scarcity demands innovative solutions, and Atmospheric Water Generation (AWG) technology offers a promising approach. This study applies a data-driven optimization methodology to enhance AWG efficiency by improving condensation surface design using Triply Periodic Minimal Surface (TPMS) structures. Five TPMS types (Gyroid, Diamond, Lidinoid, SplitP, and Schwartz) were evaluated using thermal simulations in nTop, and a regression-based predictive model was developed to assess the impact of lattice thickness and cell size on surface area to volume ratio (SA/VS) and temperature difference (ΔT). A multi-objective optimization approach, incorporating sensitivity-weighted desirability analysis, identified optimal design parameters under varying performance priorities. Results show Schwartz exhibits the highest tunability, with both factors significantly influencing its performance, while other TPMS types are primarily governed by lattice thickness. By integrating regression modeling, multi-objective optimization, and sensitivity analysis, this study provides a systematic framework for AWG surface design, offering scalable insights for thermal management and moisture collection efficiency in sustainable water harvesting applications.Materials Science, Engineering, and Commercializatio
Diet, Eating Habits, and Lifestyle Factors Associated with Adequate Sleep Duration in Children and Adolescents Living in 5 Mediterranean Countries: The DELICIOUS Project
No full textBackground/Objectives: Sleep is a fundamental physiological function that plays a crucial role in maintaining health and well-being. The aim of this study was to assess dietary and lifestyle factors associated with adequate sleep duration in children and adolescents living in five Mediterranean countries. Methods: Parents of children and adolescents taking part in an initial survey for the DELICIOUS project were examined to assess their children’s dietary and eating habits (i.e., meal routines), as well as other lifestyle behaviors (i.e., physical activity levels, screen time, etc.) potentially associated with adequate sleep duration (defined as 8–10 h according to the National Sleep Foundation). The youth healthy eating index (Y-HEI) was used to assess the diet quality of children and adolescents. Multivariate logistic regression analyses were performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs), indicating the level of association between variables. Results: A total of 2011 individuals participated in the survey. The adolescents and children of younger parents reported being more likely to have inadequate sleep duration. Among eating behaviors, having breakfast (OR = 2.23, 95% CI: 1.62, 3.08) and eating at school (OR = 1.33, 95% CI: 1.01, 1.74) were associated with adequate sleep duration. In contrast, children eating alone, screen time, and eating outside of the home were less likely to have adequate sleep duration, although these findings were only significant in the unadjusted model. After adjusting for covariates, a better diet quality (OR = 1.63, 95% CI: 1.24, 2.16), including higher intake of fruits, meat, fish, and whole grains, was associated with adequate sleep duration. Conclusions: Adequate sleep duration seems to be highly influenced by factors related to individual lifestyles, family and school eating behaviors, as well as diet quality.Division of Researc
Analyzing Motorcycle Crashes on Rural Undivided Roads: A Data-Driven Approach
No full textMotorcycle crashes on rural undivided roadways remain a significant safety concern due to the high incidence of severe injuries and fatalities associated with these environments. This study analyzes a comprehensive dataset of 12,753 motorcycle crashes from rural undivided roads in Texas, integrating structured crash records and narrative reports from the Texas crash database. Employing a multi-method approach, the research first applies Cluster Correspondence Analysis (CCA) to identify underlying patterns in crash characteristics, followed by the estimation of cluster-based Random Parameter Logit Models to quantify the effects of rider behavior, roadway, and environmental factors on injury severity. Latent Dirichlet Allocation (LDA) topic modeling of crash narratives further supplements the analysis by uncovering key crash scenarios and thematic trends. The results consistently show that excessive speed, loss of control, helmet non-use, and hazardous roadway geometry, such as curves and grades, are primary contributors to severe and fatal crashes, particularly in high-speed run-off-road, overturn, and intersection-related incidents. Narrative analysis also highlights risks associated with nighttime visibility and animal-related crashes. The findings inform a suite of policy interventions grounded in the Safe System Approach (SSA), recommending context-sensitive speed management, rural infrastructure upgrades, helmet use promotion, and improved emergency and wildlife response as essential strategies for reducing injury severity and enhancing motorcycle safety on rural undivided highways.Engineerin
Extending a Teacher Responding Framework to University Precalculus Classrooms
No full textThis study investigates instructional discourse in university precalculus classrooms, focusing on how instructors’ question and respond to student contributions during whole-class discussions. While extensive research on teacher responsiveness exists in K-12 mathematics education, less is documented about how postsecondary instructors attend and respond to students’ mathematical thinking. The purpose of this dissertation is to extend an established K-12 teacher responding framework – the Modified-Responding Framework (Milewski & Strickland, 2020) – to the context of university precalculus instruction. The results of this study highlight the possible need for professional development at the university level to extend the repertoire of instructors’ questioning and responding habits.Mathematic
Miniaturized Log-Periodic Saw-Toothed Antenna on Flexible Substrate for Broadband Applications
No full textThe paper explores the synthesis, modeling, and testing of a miniaturized log-periodic saw-toothed antenna (LPTA) to be used in a broadband scenario (3-12 GHz operation). This antenna is about 56 mm in size and printed on a flexible Kapton substrate of 125 µm thickness and relative permittivity of 3.4 so that it is conformable to integrate around a curved or an irregular surface. To achieve higher performance and radiation characteristics, the log-periodic geometry was provided with the sawtooth structure. A tapered balun was added and incorporated to enable impedance matching and generate a balanced feed, causing the radiating profile to be much more stable and efficient. HFSS was utilized to simulate the antenna in order to analyze some basic parameters like the return loss (S11), the input impedance, the VSWR, the gain, and the radiation patterns. Comparative tests of configurations with and without the balun indicated much better impedance matching and directional stability. Experimental validation used near-field measurement at the STAR Laboratory, 3D printing of silver nanoparticle ink was done on inkjet and aerosol jet, and a prototype was created. The largest measured gain was about 1.8 dBi, and beam linear polarization over the operating band, as verified by axial ratio plots. The pattern measurements in the XY, YZ, and ZX planes at the frequencies of 4, 6, 8, and 10 GHz demonstrated that the beam symmetry in the matched configuration is improved, and the distortion is reduced. This paper shows that high-performance, flexible, and compact broadband antennas can be produced to support the next generation of wireless and sensing purposes.Engineerin
"Who's Supporting the Support Staff?" A Case Study of Support Staff of Color and their Perceptions of Influence on Student Success
No full textThis qualitative study involved exploring the impact of support staff members of color in high schools and how they perceive their role in student success. A case study approach was used to contextualize the perceptions of individuals whose work is to support students through a non-instructional role. Participants were six custodians who worked in central Texas high schools. Their lived experiences were recorded through qualitative, individual interviews and focus groups. Data were then analyzed to identify emergent themes, which included connection to self, connection to others/relationships, and connection to community. Sub themes throughout aligned with the theoretical framework for the study, which included Yosso’s (2005) community cultural wealth and Guajardo et al.’s (2016) ecologies of knowing. Implications for campuses include the need for additional relationship building between faculty and staff, enhanced professional development for support staff, and connection and recognition of support staff to the campus outside of job role duties.Counseling, Leadership, Adult Education, and School Psycholog
A Novel Steroidogenic Action of Anti-Müllerian Hormone in Teleosts: Evidence from the European Sea Bass Male (Dicentrarchus labrax)
No full textThe Anti-Müllerian hormone (AMH) is widely recognized for promoting Müllerian duct regression in higher vertebrates and regulating key reproductive functions like steroidogenesis, folliculogenesis, and Leydig cell development. In teleost fish, which lack Müllerian ducts, Amh primarily influences male reproductive functions, including sex determination, testis differentiation, and germ cell proliferation. In adult fish, Amh supports gonad development and spermatogenesis, but its role in teleost gonadal physiology remains largely underexplored. This study reveals a novel steroidogenic function in the European sea bass (Dicentrarchus labrax) using in vitro testis culture, in vivo plasmid injection, and cell-based transactivation assays. The Amh-induced significant increase in androgen levels was also confirmed in Japanese medaka (Oryzias latipes) treated with recombinant sea bass Amh. Beyond activating the canonical Smad pathway, Amh also triggered the cAMP/PKA signalling pathway via its cognate type II receptor, Amhr2. Inhibitors of these pathways independently and synergistically counteracted Amh-induced CRE-Luc activity, indicating pathway crosstalk. Moreover, inhibition of the cAMP pathway suppressed Amh-induced androgen production in testis cultures, emphasizing the crucial role of protein kinase A in mediating Amh steroidogenic action. These findings uncover a novel steroidogenic function of Amh in teleosts and highlight its broader role in male reproductive physiology.Biolog
Oral history interview: Carol Winkler
No full textEdited transcript file (.pdf), closed captioning, unedited video, and raw transcript (.pdf) available.Interview with Robert Winkler, who shares about his mother's life in both in the Women's Army Corps and after. He discusses her life as a young woman, the marriage to his father, raising children, her work, her passing, and her legacy of kindness