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Analyzing Sport-related Concussions: A Kinematic Assessment of the Buffalo Concussion Treadmill Test
No full textBackground: The Buffalo Concussion Treadmill Test (BCTT) is a graded exercise test to assess exercise tolerance for athletes with sport-related concussions (SRC). Research suggests that kinematics are altered following an SRC. Currently, no research has analyzed knee biomechanics during the BCTT, following an SRC. Purpose: To use markerless motion capture to examine flexion and extension of the knee during the BCTT following an SRC within 3 days and while the athlete is symptom-free. Methods: 11 NCAA Division I athletes who are within 72 hours post-SRC, and 11 controls (CON) participated in the study. The BCTT was performed via the standardized guidelines. Each minute, the subjects' joint angles were tracked using markerless motion capture. A 1x16 ANOVA with planned contrast was run to determine minute-by-minute differences between SRC and SF. A 2X8 ANOVA with planned contrast was run to compare CON and SF. Data were normalized to the lowest common denominator of time. Results: Significant differences were found in flexion/extension during minute 2 (SRC=11.30±4.55°, SF=9.23±2.46°; p=0.037), minute 3 (SRC=10.85±4.01°, SF=8.63±2.67°; p=0.037), minute 4 (SRC=10.92±4.37°,SF=8.15±2.62°; p=0.010), minute 5 (SRC=10.14±4.67°, SF=7.75±2.31°; p=0.025), minute 6 (SRC=9.29±5.07°, SF=6.80±2.74°; p=0.020), minute 7 (SRC=9.56±4.98°, SF=6.65±2.77°; p=0.007), minute 8 (SRC=9.53±4.16°, SF=6.56±2.74°; p=0.005) of mid-stance comparing SRC to SF. Conclusion: During the BCTT, SRCs cause more knee flexion during midstance, so athletes adopt a crouched gait
Analysis of Fine Asphalt Concrete Mixture Gradations from Various Sources to Enhance Durability
Get PDFIn an effort to reduce the negative effects on our environment caused by the construction of vital economic infrastructure such as the roadway system, extending pavement service lives will help lessen the toll on the former. One of the factors that can influence the durability of asphalt mixtures, is the gradation. This thesis will look into the effect of fine aggregate dense gradations on asphalt mixture durability for sources from the state of Nevada. Based on the available literature, finer gradation asphalt mixes have lower air void content and therefore higher moisture damage resistance. This is because the finer aggregates tend to fill the voids that were otherwise not filled by the coarse aggregates. This will lead to enhanced durability because less water and air can penetrate the mix, leading to less oxidation and moisture damage. Finer gradations can also offer better cracking resistance due to the higher asphalt content and the lower air voids can create better cohesion in the mix. It was widely accepted that coarser mixes, such as SMA, provided better rutting resistance especially in heavy traffic conditions and higher temperatures due to the improved stone to stone contact which may act as a stronger aggregate skeleton for the mix. However, recently more DOTs have been shifting to finer gradation as studies have shown that they can have better rutting resistance. This research suggests there are a few factors to consider when designing an asphalt mixture, including the traffic loads and environmental conditions. However, a finer gradation can provide an overall improved moisture resistance and fatigue life so it should be considered carefully when designing asphalt mixtures. Therefore, a well-balanced mix design that can achieve the best rutting and cracking resistance is recommended to achieve the most ideal gradation that works best for the specific regions of Nevada
Nevada State Climate Office Quarterly Report & Outlook, April - June 2024
No full textNotable weather and climate in Nevada that occurred from April to June of 2024
CANNABIS LEGALIZATION: UNDERSTANDING HOW EVOLVING POLICY LANDSCAPES AFFECT EMERGING ADULTS’ CANNABIS-RELATED BEHAVIORS IN THE US (please leave this as this is the testing item)
No full textBackgroundAn increasing number of US states have legalized cannabis for recreational, or adult, use, where access to cannabis products is limited only by age. The largest proportion of cannabis users are among emerging adults (EAs) compared to younger and older people. EAs are a unique population group, transitioning from adolescence into adulthood, where substance use experimentation is more common than in other life stages; therefore, it is important to understand the effects of cannabis legalization on this group. PurposeThe three objectives of this dissertation were to 1) map and summarize the scientific literature on cannabis advertising effects on perceptions and behaviors, 2) describe cannabis use behaviors among EAs in the US and compare use behaviors in states with and without adult-use legal sales and among EAs under (18-20 years old) and over (21-25 years old) the legal age to purchase cannabis, and 3) test the effects of cannabis advertising stress relief messaging on cannabis-related perceptions and intentions among EAs who are under the legal age to purchase cannabis (18-20 years old). MethodsIn study one, scoping review methods were used to map and summarize the scientific literature on cannabis industry advertising effects on cannabis-related perceptions, beliefs, attitudes, and behaviors. In study two, a cross-sectional study design was used to understand EAs’ cannabis use patterns by adult-use legal sales status and age group. A subsample of EAs from the 2021 US data were drawn from the International Cannabis Policy Study (ICPS) (n=3,467), an online survey administered annually that identifies the impacts of cannabis legalization on cannabis perceptions, use, and retail sales. EAs’ use frequency, mode, multi-modal use, cannabis source, and source legality were described and differences by state legality and age group were analyzed using adjusted logistic and linear regression. In study three, participants aged 18-20 years participated in a between groups eye tracking experiment, where they were randomized to a control (cannabis availability messaging) or an experimental (stress relief messaging) group to view cannabis ads. Pre-appointment survey, eye tracking, and post-survey data were collected. To understand any differences, group means were compared and linear regression was used to understand the association between the eye tracking measures and perception outcomes. ResultsStudy one
There were 17 studies that fit the eligibility criteria which were charted and summarized using two themes: cannabis-related perceptions, attitudes, and beliefs and cannabis-related intentions and behaviors. Most studies used cross-sectional designs and participant self-reported recall to measure advertising exposure. The majority of studies found that cannabis advertising exposure was associated with positive cannabis-related perceptions, attitudes, and use behaviors. Study twoAmong EAs aged 18-25 years old, 33% (95% CI: 30.9, 35.2) used cannabis in the past 12-months (P12M) and half reported being a never user. Among P12M users (n=1,248), over-age EAs (21-25 years old) in legal states had higher odds of using multiple modes of use (aOR 1.34; 95% CI: 1.04, 1.72) than over-age EAs in non-legal states. Both under- (18-20 years old) and over-age EAs in legal states had higher odds of obtaining cannabis from a dispensary than in non-legal states (aOR 2.14; 95% CI: 1.31, 3.48 and aOR 6.02; 95% CI: 4.40, 8.24, respectively). Over-age EAs in legal states had lower odds of obtaining cannabis from a dealer than over-age EAs in non-legal states (aOR 0.3; 95% CI: 0.24, 0.44). Under-age EAs in legal states who used cannabis concentrates used them on almost 34 more days in the P12M than under-age EAs in non-legal states (95% CI: 10.33, 56.21). All EAs in legal states reported obtaining almost 25% more legally sourced cannabis in the P12M than EAs in non-legal states (95% CI: 19.32, 29.94). Study threeThere were 90 participants who viewed the ads; overall, no group differences were found for the eye tracking fixation data nor for the perception outcomes. The results from the linear regressions showed that longer fixation duration on the stress relief messaging (experimental group) was associated with increased belief in stress relief (β=0.39; p=0.0285), lowered harm perceptions (β=-0.61; p=0.0016), and greater intention to use (β=0.87; p=0.0021). No associations between fixations and the perception outcomes were found in the cannabis availability messaging group. Additionally, the stress relief messaging lowered harm perceptions among non-past 30-day (P30D) cannabis users while the cannabis availability messaging had no effect on non-P30D users (2.35 vs. 2.71, p=0.0550). ConclusionsUnderstanding the effects from legalization on EAs’ perceptions and behaviors is vital for informing future research and state policy. The research presented in this dissertation shows that cannabis advertising exposure, such as billboards, print ads, and internet ads, affects perceptions, attitudes, and behaviors. EAs’ cannabis use patterns are also associated with adult-use legal sales in the US, where under-age EAs in states with legal sales reported more concentrated cannabis use and greater access to legal cannabis dispensaries and products. These findings suggest that increased access to cannabis through the legal marketplace and perceived normalization of use in the US might be mechanisms driving increases in use, particularly use of concentrates. Additionally, the eye tracking experiment revealed that among under-age EAs, there was an association between longer fixation times on the stress relief messaging and increased belief in stress relief, lowered harm, and greater intentions to use. Future studies could investigate the influence of health and wellness advertising messaging on cannabis-related perceptions and behaviors. Eye tracking technology may be a particularly useful tool for understanding viewing patterns for ads in general or for specific messaging. Research studies could also explore under-age EAs’ experiences obtaining cannabis and their perceptions on the social norms related to use. Policy recommendations include addressing cannabis advertising density in an effort to reduce exposure and limiting stress relief messaging on cannabis advertisements due to the potential influence on under-age EAs. Often, cannabis regulations aim to limit advertising appeal and subsequently, use, among youth and children. Therefore, policies that expand their definitions of appeal to include those of older adolescents and EAs would offer greater protection from influential messaging, thereby reducing harm among a population at increased risk of use
The development and plasticity of visuo-spatial orienting behaviors and underlying circuitry in adolescent mice
Get PDFSex differences in visual processing during behavior exist across a wide variety of species, from flies to humans. However, it remains unclear whether sexual dimorphism in natural visual behavior exists for standard laboratory strains of mice, a prominent model for understanding the neural basis of behavior in mammals. To fill this critical hole in our understanding, we quantitatively compared both insect predation behaviors and visual motion-induced orienting between adolescents and adults in both sexes of C57BL6/J mice. We found that adolescent mice of both sexes fed ad-libitum on standard mouse chow detected and approached live insects faster, more frequently and spent more time in proximity to insects without attacking, reminiscent of object play-like behavior. In contrast, mature adult mice of both sexes engaged in alternating bouts of avoidance and approach when first exposed to insects, with more frequent biting and killing, even in the absence of food restriction. Unexpectedly, we found that adolescent females displayed the most appetitive orienting response towards natural prey and “prey-like" sweeping visual motion stimuli presented on computer screens relative to any other group. On the other hand, adolescent males were more likely to arrest in response to similar visual motion stimuli and more quickly transition into predating on live insects. We found that these sexual dimorphisms in response to visual motion were selectively maintained in females if animals received hunting experience specifically during adolescence. Remarkably, this enhanced visual responsiveness was not context specific and adolescence-hunting-experienced females also responded more robustly to overhead looming stimuli relative to all other groups tested. Thus, we discovered an age- and sex-dependent difference in visual orienting behavior related to salient visual motion detection. Importantly, our findings argue that assessment of “innate" visual responses to visual stimuli in mice must consider age, sex and the significant early experiences of animals for optimal interpretation of findings
Design, Synthesis, and Evaluation of Covalent CADA Analogues as Potent TLR4 Downmodulator for the Treatment of Opioid Use Disorder
Get PDFToll-Like Receptor 4 (TLR4) is involved in the innate immune response and the pathogenesis of opioid use disorder (OUD). Opioids interact not only with neuronal sites but also with glial cells thereby activating these cells, thus leading to the release of neuroexcitatory substances and neuroinflammatory cytokines, contributing to neuroinflammation, pathological pain and neuronal damage. Current therapeutic strategies, though effective, present significant limitations. Given these challenges, alternative therapeutic approaches are essential. Cyclotriazadodecane (CADA) a small molecule initially known to reduce human CD4 (hCD4) protein in a signal peptide (SP) dependent way can downregulate other proteins going through the Sec61 pathway, including TLR4. This work aims to design and synthesize new covalent CADA analogues targeting the SP of TLR4 to address OUD. This study explores the synthesis of different covalent CADA analogues targeting the SP of TLR4, which contains a cysteine residue in its hydrophobic region, making it a viable target for covalent modulation. So far, more than twenty covalent CADA analogues have been synthesized by modifying the tail region and post modification of the sidearm. The synthesis of some of the analogues involves the debenzylation of CADA and subsequent amide coupling reactions to introduce various electrophilic groups to enhance the binding affinity and specificity towards TLR4.The synthesized analogues were characterized using various spectroscopic techniques and confirmed to be pure by elemental analysis. Once the first aim has been accomplished, a novel screening method was developed to evaluate the efficacy of the synthesized CADA analogues in downmodulating TLR4. The assay measured SEAP activity as an indicator of TLR4 activation, providing a quantitative assessment of the downmodulating effects of the CADA analogues. Here in, ten CADA analogues have been screened. While some of them are either toxic or not active, lycorine showed significant TLR4 downmodulation with decreased production of proinflammatory cytokines, suggesting a potential therapeutic effect. This screening method developed provides a robust platform for identifying potent TLR4 downmodulators. Future research should focus on optimizing the pharmacokinetic properties of these CADA analogues and conducting in vivo studies to validate their efficacy and safety. Additionally, exploring the broader applicability of this approach to other neuroinflammatory conditions could further enhance the therapeutic potential of CADA analogues. Oxidative heterofunctionalization of alkenes is a versatile strategy for the synthesis of complex, saturated heterocycles. Additionally, this transformation allows for the formation of medicinally valuable bicyclic compounds via pendant nucleophiles. In this work, we applied previously reported oxidative photocatalytic conditions by the Yoon group to cyclize novel substrates containing N-tosyl amines into medicinally relevant bicyclic scaffolds. Proof of concept for the application of these conditions was established through the isolation of the [3.2.1] bicyclic product. The initial result was optimized utilizing photochemical high throughput experimentation platforms focusing on photocatalyst, solvent, Cu (II), and light sources as variables. The overall yield of this cyclization reaction was improved while also confirming the formation of an additional cyclized side product. We envision further optimization of yield and selectivity as well as substrate scope expansion, which will enable access to other bicyclic cores, including [2.2.1] and [1.1.1] scaffolds
Thermal Behavior of the TN-32B Spent Nuclear Fuel Cask under Storage and Vacuum Drying Conditions
Get PDFIn this work, computational models are developed to predict the temperatures in a spent fuel cask under storage and vacuum drying conditions. In particular, the TN-32 spent nuclear fuel cask was modeled because it is one of the few demonstration casks with publicly available experimental data to validate computational models for storage and vacuum drying conditions. Computational fluid dynamics models of this cask were developed to investigate common modeling techniques, assumptions, and uncertainties to identify and quantify their effects on temperature predictions. Two-dimensional and three-dimensional models of the TN-32 spent nuclear fuel cask are constructed and simulated in the ANSYS package for comparison with experimental data. The gaps between the cask components were found to have a strong influence on assembly temperatures. The size of these gaps is unknown due to the potential shifting of fuel and cask components, manufacturing tolerancing, and thermal expansion. During vacuum drying, the effect of rarefaction at the helium-solid interfaces caused significant temperature increases in the fuel region. This effect is strongly dependent on pressure, gas species, and gap sizes, which are all unknown during the vacuum drying process. This dissertation was divided into three main sections, each one is a stand-alone journal paper. In the first paper, two-dimensional detailed models of the TN-32B were used to investigate different peripheral basket/rail gap geometries and their effect on temperatures under storage and vacuum drying conditions. The basket/rail gap is explicitly modeled to have three different widths, 0 mm, 2.54 mm, and 4.78 mm. The basket and fuel assemblies are also explicitly shifted within the model to investigate two leaning geometries where the basket contacts one or two sides. Fuel region temperatures are shown to be very sensitive to gap width and pressure with vacuum drying induced rarefaction potentially causing as much as a 51°C increase in fuel region temperatures. In the second paper, full homogenous three-dimensional models were developed and used to conduct an uncertainty quantification (UQ) analysis of the collective and individual effects of nine gaps, between solid components in the TN-32B, on temperature prediction. A global UQ method that uses the Latin Hypercube Sampling technique is used to quantify uncertainty in temperature prediction due to uncertainty in gap widths at all locations of internal temperature measurement in the TN-32B from the High Burnup Demonstration cask. Results indicate that the effects of different gaps are location-dependent with the total effect ranging from ±12°C to ±21°C and that uncertainty in the basket/rail gap accounts for approximately 50% of all uncertainty in temperature predictions due to uncertainty in gap widths. In the third and final paper, a one-eighth three-dimensional model of the TN-32B is constructed with a detailed representation of the fuel assemblies. The same computational mesh was used to generate a homogenous model, with the fuel regions represented as porous heatgenerating blocks. An assembly-of-interest fuel region heat loading that allows for reasonable comparisons with experimental data is proposed and used in the simulations. Effective thermal and flow properties for homogenous model were derived from sub-models. The temperature and flow velocity predictions were compared on a point-to-point basis between the detailed and homogenous models throughout the fuel region. The temperatures at 63 locations obtained from the detailed model are compared to data from the High Burnup Demonstration project and the results showed a difference ranging from -7°C to +10°C. The homogenous model accurately predicts temperatures relative to the detailed model, with the most notable differences observed at lower elevations within the fuel regions. 95% of fuel region temperatures are within 2°C between the models
The Role of K-12 Public School Principals in Culturally Sustaining Mathematics Education
No full textThe study was designed to investigate how K-12 school principals evaluate equitable mathematics teaching practices using culturally sustaining pedagogy (CSP) through the conceptual lens of culturally sustaining leadership (CSL). The study focuses on the criteria public school principals use to evaluate mathematics instruction and the guidelines they use to support the professional growth of mathematics teachers to better ensure that all students gain access to grade-level mathematics knowledge. The study was conducted using semi-structured, one-time interviews with public school principals who work in traditional school settings. Traditional public school settings were selected because these schools are required to accept enrollment of all students zoned for their school, whereas charter, private, and online schools have a selective enrollment process via applications. The transcripts were analyzed and coded using an a priori codebook created by the researcher using the first interview and developed over the subsequent interviews for which all data were coded and analyzed. Using a non-linear approach, relationships among codes were collapsed into larger overarching themes and reported in the findings
The Impact of Police Officer Presence on Driver Behaviors Within Active School Zones
No full textChild pedestrian injuries and fatalities remain a concern amidst evolving roadway conditions, larger and faster vehicles, and infrastructure deficiencies. While national and local advocacy efforts, such as Safe Routes to Schools (SRTS) programs and Vision Zero Washoe County serve to educate pedestrians, school officials, and drivers, pedestrian fatalities and crashes involving Washoe County School District (WCSD) students are still at record levels. The study investigates the effectiveness of law enforcement presence in active school zones on mitigating vehicle speeds, a critical factor in child pedestrian safety. Utilizing LiDAR technology and in collaboration with the Reno Police Department (RPD), the hypothesis is that an officer's presence will cause drivers to significantly reduce their speeds. Three case studies conducted at local schools indicated a modest, though statistically significant, reduction in speeds with officer presence but highlighted challenges in sustaining this effect after the officer's departure, along with variations in driver behaviors based on the officer's chosen post within the school zone. This data underscores the complexity of school zone safety and emphasizes the importance of multifaceted approaches involving law enforcement, infrastructure improvements, and community engagement