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Development of a descriptor-based database for high-entropy ultra-high-temperature diboride ceramics
No full textHigh-entropy ultra-high-temperature ceramics are a new frontier of material discovery due to their many beneficial material properties. Some of these properties are high heat resistance, corrosive and ware resistance, as well as possessing high hardness. Recent interest in hypersonic material design proves to be viable due to their ability to withstand extreme environments such as those encountered with hypersonic flight. Limited experimental data plagues high-entropy ceramics due to their recent discovery within the past ten years. This study focuses on gathering as much information towards high-entropy diborides which has gained interest in the aerospace industry. Descriptors are used to capture material properties of high-entropy diborides to predict the phase of these materials. Such descriptors are categorized as either elemental descriptor, thermodynamic descriptors and Density functional theory descriptors. Descriptors are obtained from various literature along with some of the data provided on high-entropy diborides. The database focuses exclusively on equimolar concentrations of transition metal diboride constituents. Missing datapoints for descriptors are calculated with formulas originating from the rule of mixture. Some descriptors require density functional theory calculations which require time-extensive computational power. A total of 333 high-entropy diborides are found within the database with thirty-four descriptors. Once descriptor data entries are submitted in the database, key descriptors are plotted to identify trends for phase stability. Vital descriptors that are essential in phase predictions stem from total valence electron concentrations, the disordered enthalpy-entropy descriptor, enthalpy cost, entropy-formation ability, lattice size difference, and volume difference
Stress-Survival Pathway Genes In Colorectal Cancer: Crc Progression And Hispanic Disparities, Highlighting Mcm10 As A Potential Player
No full textDespite advances in screening and treatment, colorectal cancer (CRC) remains a leading cause of cancer-related deaths in the U.S., with notable disparities across racial and ethnic groups. Hispanic populations face a disproportionate burden, underscoring significant differences in incidence and outcomes. This study examines the role of the Stress-Survival Pathway (SSP) in colorectal cancer (CRC), with a focus on addressing health disparities among Hispanic populations. Twenty-eight differentially expressed SSP genes identified from bioinformatic analysis were validated in CRC cell lines and cDNA arrays using qRT-PCR and tissue microarrays by immunohistochemistry. SSP genes were further analyzed in CRC tissues from Hispanic and non-Hispanic White (NHW) individuals, including early-onset and late-stage samples. Among all SSP genes, we selected MCM10 for further investigation due to its limited studies in CRC and consistent overexpression across all experiments, including those involving Hispanic CRC samples, highlighting its potential role in CRC disparities. We hypothesized that MCM10 plays a critical role in CRC pathogenesis and may contribute to the disparities in disease progression observed in Hispanic patients. We performed a series of functional assays, including proliferation, invasion, migration, cell cycle analysis, apoptosis, and reactive oxygen species (ROS) assessment, following the knockdown of MCM10, to investigate its role in CRC progression. The results indicated that silencing MCM10 significantly inhibited cell proliferation, reduced invasive and migratory capabilities, increased apoptotic rates, and altered cell cycle progression while also affecting ROS levels in cancer cells. Additionally, we conducted RNA sequencing and mass spectrometry following MCM10 knockdown, which enabled us to integrate transcriptomic and proteomic analyses, revealing significant changes associated with PPFIA1. These findings suggest that SSP genes, particularly MCM10, play a significant role in CRC progression and may serve as a potential therapeutic target to address ethnic disparities in CRC outcomes
CCR7 Regulated Mechanisms that Limit the Adaptive Immune Response
No full textC-C chemokine receptor 7 (CCR7) is critical in guiding T cell migration within the thymus and peripheral lymphoid tissues, shaping the adaptive immune response by promoting central tolerance and regulating immune homeostasis. Although its role in lymphocyte trafficking is well established, the molecular mechanisms by which CCR7 influences thymocyte development and T cell receptor (TCR) repertoire formation remain less understood. This study examines how CCR7 deficiency impacts thymic selection, TCR diversity, and the signaling events that shape repertoire restriction. Using a homozygously deleted CCR7 murine model, we found that the absence of CCR7 results in a less restricted TCR repertoire than wild-type mice, failing to eliminate potentially auto-reactive T cell clones properly. Our data revealed that CCR7 signaling during double negative (DN) stages of thymocyte development restricts TCRβ diversity by limiting J-segment trimming. Stimulation of CCR7 by its ligands at this stage enhances TCR signaling through the ZAP-70/LAT/PLCγ1 pathway, reinforcing the kinetic proofreading mechanisms essential for the discrimination of self and non-self antigens. Importantly, the broader and less selective TCR repertoires in the CCR7-deficient animals correlate with elevated antibody titers and immune dysregulation. These findings define a previously unrecognized function of CCR7 in thymocyte development, TCR function and supporting immune tolerance. Our findings aim to elucidate the molecular mechanisms through which CCR7 contributes to immune regulation, offering important insights for the development of novel immunotherapeutic strategies and approaches to immune modulation
Mechanical Characterization of M Plane (10-10) and C Plane (0001) Gallium Nitride Semiconductors via Spherical Nanoindentation
No full textGallium nitride\u27s (GaN) mechanical characterization is essential for evaluating its performance and long-term dependability, especially when subjected to mechanical stress and irradiation. The design and optimization of GaN-based devices, which are extensively employed in high-power electronics and optoelectronics, depend on an understanding of these characteristics. Mechanical characterization allows for the evaluation of key characteristics, including stress distributions, representing the spatial variation of internal stresses under applied loading, and pop-in events, which correspond to abrupt displacements associated with the onset of dislocation nucleation and slip. These features are essential for understanding the anisotropic (direction-dependent) response of the material to external forces and environmental conditions. Additionally, the use of GaN in harsh environments, such as those exposed to radiation, can lead to degradation, which may affect its structural integrity and functionality. Through the examination of load-displacement responses acquired using a spherical indenter, the mechanical characteristics of gallium nitride wafers with c-plane (0001) and m-plane (10-10) orientations are examined in this work. A useful method for assessing important mechanical traits like hardness, elastic modulus, and plastic deformation behavior is spherical indentation, which offers a more even stress distribution than sharp indenters. By utilizing this technique, the research aims to enhance the understanding of orientation-dependent mechanical behavior, emphasizing the variations in elastic and plastic responses that are essential for maximizing performance in a range of applications, particularly those where directional properties are significant
Transnational Teachers On Both Sides Of The U.S.-Mexico Border: Exploring Their Identities And Conocimiento. A Phenomenological Study With A Comparative Stance
No full textThe transnationalism phenomenon is at the core of an increasingly globalized world. This phenomenological study with a comparative stance explores the lived experiences and perspectives of teachers with a transnational migration background with regards to how they [re]construct their identities and conocimiento. It compares and contrasts the histories and insights from participants in the borderlands with those from the heart of Mexico. Specifically, this study contributes to the under-explored body of literature which has taken a comparative stance in looking at transnationalism in education on both sides of the U.S.-Mexico border. Data derived from migration memory maps and in-depth, phenomenological interviews with a total of 10 participants (five participants in each of the two settings). Data analysis was guided by a three-pronged framework: transnationalism theory, theory of conocimiento, and identity theory, through both inductive and deductive data coding. Findings denote the different stages of conocimiento that the participants experienced, as well as borderlands epistemologies and imagined transnationalism
Terrane Accretion In The Trollheimen And Dovrefjell Regions Of The Scandinavian Caledonides, Norway
No full textFollowing closure of the Iapetus Ocean, the paleocontinents of Laurentia and Baltica collided to form the Caledonian Orogeny. During this closure and subsequent collision, island arc terranes and microcontinents were accreted and subducted underneath the Norwegian continental margin. These terranes are preserved in central Norway, specifically in the Dovrefjell and Trollheimen mountain ranges. The order in which these terranes accreted to the continent and when this occurred is not well understood. To determine this stacking order, I will be using P-T path modeling, U-Pb zircon dating, and structural position. Knowing the degree, progression, and geologic age of metamorphism, and tectonostratigraphic position will reveal how the units were assembled
Studies to Delineate the Structure and Function of the Human Ventricular Myocardium in Subjects with Type-II Diabetic Cardiomyopathy
No full textHeart failure, an abnormal heartbeat, and sudden death are all possible outcomes of preexisting or underlying cardiac disease. Heart disease is highly correlated with diabetes, causing heart pain and shortness of breath. In patients without other cardiac conditions, diabetic cardiomyopathy is a process that affects the myocardium over a long period of time. This disease has a complicated pathophysiology that can be broken down into processes that lead to diastolic and/or systolic dysfunction. However, the pathophysiological differences between normal, diabetic, and diseased cardiac tissues have not been thoroughly studied. Therefore, in this research, we directed our efforts to perform a pilot characterization to distinguish between Type II diabetic and non-diabetic human ventricular myocardium structure and physiology. Two distinct human samples were used in the research: Tissue samples from adult ventricular myocardium from (1) diabetic and (2) nondiabetic donors. These samples were subjected to the following analysis, including (i) surface and micro-structural analysis; (ii) mechanical characterization; and (iii) gene expression studies. The surface and structural details of the tissues were examined with scanning electron microscopy (SEM) imaging. However, soft tissue analysis remains a challenge because of its limited contrast nature, which makes it difficult to distinguish structures in the soft tissue, such as the heart muscle. The primary techniques were pivotal to our study, there are some parallel methods adopted to strengthen our existing methods. HIM [Helium Ion Microscopy], Light sheet microscopy with Lectin 488 and propidium Iodide and fast green staining, and Micro CT with Lugol\u27s agent. The mechanical properties of the tissue samples were studied by rheological analysis. Following (ribonucleic acid) RNA extraction, the samples were subjected to RNA sequencing to determine gene expression in both samples. The results of this fundamental study demonstrated that cardiac tissue structure and function could be clearly distinguished between diabetic and non-diabetic ventricular myocardium. Outcomes will drive the creation of an engineered diabetic human tissue on a chip model for drug studies and other mechanistic investigations
Associations Between Mental Health Outcomes And Discrimination And Victimization Among Adult LGBTQ+ Community Members Or Guardians Of LGBTQ+ Children, 2023-2024
No full textBACKGROUND: LGBTQ youth face unique challenges and experiences that can significantly impact their mental well-being. Discrimination, stigma, prejudice, and struggle for self-acceptance contribute to increased rates of mental health issues within this population. Almost one in 8 people, or 970 million individuals worldwide, were living with a mental disorder. PURPOSE: Assess the relationship between discrimination and victimization and mental health outcomes among sexual and gender minorities (SGMs) in the Paso del Norte Region. METHODS: Data was collected through a cross-sectional needs assessment survey among adult LGBTQ+ community members or parents/guardians of LGBTQ+ children/youth living in New Mexico or Texas in 2023-2024. Descriptive statistics and bivariate associations between mental health outcomes with discrimination and victimization were determined using appropriate statistical methods using SPSS Version 29.0. Adjusted analyses were controlled for Mexican/Mexican-American/Chicano ethnicity, White/Caucasian race, and living in a Texas border county. RESULTS: Median age was 38.0 years old, 65.0% identified as Hispanic, the majority were assigned female at birth (64.6%), and half (50%) identified as women. The most prevalent sexual orientation was queer (45%), followed by gay (31.3%). The Patient Health Questionnaire (PHQ-4) indicated that 32.5% of participants had depression and 40.0% had anxiety in the past two weeks. After adjustment, median (Q1, Q3) scores for mean discrimination (0.4 (0, 1.2)) and total discrimination (1 (0, 4)) were both scores were higher for those with depression (p-value\u3c0.001 and p-value=0.0031), respectively) while statistically significantly lower (p-value=0.027) and not significant (p-value=0.118) for those with anxiety, respectively. After adjustment, median scores for mean victimization (0 (0, 5)) and total score (0 (1, 0)) indicated low levels of victimization; those with depression had higher scores (p-value=0.095 and p-value=0.301, respectively) anxiety (p-value=0.175 and p-value=0.345, respectively) but not statistically significant. CONCLUSION: Discrimination scores were higher for those experiencing depression and anxiety; however, victimization scores were similar
The role of ecological nostalgia and prostalgia in pro-environmental intentions
No full textClimate change will have catastrophic impacts on humans and the natural environment. However, despite abundant evidence suggesting climate change is happening, climate change mitigation remains a highly polarizing issue in the U.S. Addressing this challenge requires social science research to tailor climate change information to resonate with both liberals and conservatives. Certain concepts, such as nostalgia and prostalgia - a sentimental longing for the past and future - have yet to be explored in the context of pro-environmental behaviors within liberal and conservative samples. Specifically, the longing or sentimental attachment to a past or future natural environment (i.e., ecological nostalgia and prostalgia) has yet to be studied. Thus, the proposed research investigates the significance of ecological nostalgia and prostalgia with eco-friendly intentions through two studies. Study 1 (N = 203) examined the relationship between nostalgia, prostalgia, and eco-friendly behaviors by examining measures association among these variables. Study 2 (N = 148) experimentally investigated the extent to which eco-nostalgia and eco-prostalgia message frames influence environmentally friendly intentions across a more politically conservative sample utilizing infographics. In Study 1, prostalgia and response self-efficacy were associated with multiple eco-friendly behavior indices. Study 2 showed no significant differences between the types of infographics received. Vignette clarity, feeling prostalgic, and response self-efficacy were positively associated with eco-friendly behavior measures. Findings from studies 1 and 2 suggest that response self-efficacy and ecological prostalgia might play an important role in environmentally friendly intentions in more conservative individuals. Future studies should examine the role of response self-efficacy and ecological prostalgia message framing
The Bullied Prairie Vole: Modeling Depression And Anxiety Through Social Defeat Stress
No full textStress-induced illnesses, such as major depression and anxiety, are significant global causes of disability. This highlights the need for reliable animal models that accurately mimic social stress-induced maladaptations, thus, allowing the experimental study of the etiology of such disorders. Prairie voles (Microtus ochrogaster), known for their human-like bi-parental behavior and monogamous partner preferences, are a relevant model for the study of stress-induced psychopathologies. For this reason, in this dissertation, I examined whether exposing voles to the social defeat stress (SDS) paradigm, an experimental approach that captures bullying behavior, would result in both depression and anxiety-related profiles. To do this, experimental voles were exposed to 10-minute agonistic interactions with a paired male aggressor over 10 consecutive days, as it is conventionally done in laboratory mice. Control animals were housed under similar conditions but did not experience stress. To evaluate the effects of SDS on depression-related behavior, I adopted (1) the social interaction test, (2) sucrose preference, and (3) Morris water maze tests, which are validated approaches to assess depressive-relevant phenotypes (i.e., social withdrawal, anhedonia, and spatial memory impairment, respectively). Additionally, I evaluated responses to open-space exploratory behavior on the (4) light/dark box and (5) elevated plus-maze tests, since they are commonly adopted to study anxiety-related behavior across rodent species. I found that SDS decreased body weight, sociability, sucrose preference (anhedonia), exploratory behavior, and impaired spatial memory performance. No changes in general locomotor activity were noted between the experimental groups. Collectively, the findings of this dissertation support the notion that the SDS model, in male prairie voles, is a valuable tool for studying stress-induced phenotypes that resemble human-like depression and anxiety-relevant profiles