Browsing by Subject "stress"

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Active Stress Field in the Texas Panhandle
(1984) Budnik, Roy T.
The south-central and southwestern United States can be divided into three distinct provinces based on the present distribution of stress: (1) Midcontinent, (2) southern Great Plains, and (3) Basin and Range (fig. 1; Zoback and Zoback, 1980). The Midcontinent province, a tectonically stable region extending from the Appalachians to the Texas Panhandle, is undergoing compressive stress in a NE-SW direction. The Basin and Range province, which includes the area from the Rio Grande Rift in central New Mexico to California and Oregon, is defined by active extension in a WNW-ESE direction. The southern Great Plains province is characterized by NE-SW extension. The Palo Duro Basin lies near the boundary between the southern Great Plains and Midcontinent provinces (fig. 1). The present distribution of stress within the southern Great Plains province was defined by Zoback and Zoback (1980) on the basis of the NW-SE alignment of Late Cenozoic volcanic centers in northeastern New Mexico and fracture orientations in hydraulically fractured wells in the Permian Basin (fig. 2; Table 1). The orientation of stress in the southwestern part of the Midcontinent province is based on the hydraulic fracturing of a single well in the Anadarko Basin (fig. 2; Table 1). Zoback and Zoback (1980) could not define the location of the boundary between the southern Great Plains and the Midcontinent provinces because of a lack of data in the Texas Panhandle.
Constraint on Stress Tensor from Slip on a Single Fault Plane
(Institute for Geophysics, 1987-09-23) Celerier, Bernard
Given a fault plane and its slip vector, the stress tensor which caused the displacement is sought. Two constraints are considered: first, a geometrical constraint that the shear stress applied to the fault plane is parallel to the slip [Wallace, 1951; Bott, 1959]; second, a frictional constraint that the shear to normal stress ratio equals tan?0 [Coulomb, 1776]. This is done in two steps. In a first step, the stress tensors that satisfy the geometrical constraint are sought. For tensors belonging to the vectorial space of solutions, shear and normal stress magnitudes become a function of the principal stress orientation s1, s2, s3 and are mapped, extending a study by McKenzie [1969]. The relationship between Mohr's [1882] (?nt) plane and these maps is described. In a second step, it is investigated which among these tensors also satisfy the frictional constraint. Within this more restricted vectorial space, there is a relationship between principal stress magnitudes, represented ?= (?1-?2)/( ?1 – ?3) and s = (?1 – ?3)/ ?1, and the principal stress orientation s1, s2, s3. Both the range of s and the spatial distribution of s1, s2, s3 are more restricted than when the geometrical constraint alone is considered. As when the geometrical constraint is solely considered [McKenzie, 1969], the principal stress orientations s1, s2, s3 may lie significantly away from and up to right angle to the P, B, T axis. However, this can happen only in two cases: (1) either the effective stress difference, s, has reached a high value, which is unlikely to happen if enough pre-existing fractures are available to release the stress, or (2) ?2 becomes close to either ?1 or ?3 and therefore barely distinguishable from it; in that case the delocalisation of the principal stress orientations is best described by a tendency for s2 to exchange role with either s1 or s3. When the stress difference remains small and ?2 reasonably away from ?1 and ?3, sf, s2, s3 approach positions that we define as the Pf, B, Tf axis and that are obtained from the P, B, T axis by a rotation of angle ?0/2 around B and towards the slip vector. This explains why the P, B, T axis gives reasonable estimates of the principal stress orientations [Scheidegger, 1964] despite objections [McKenzie, 1969]. However, whenever the fault plane can be distinguished from the auxiliary plane, Pf, B, Tf should give a better estimate [Raleigh et al., 1972]. In an area where many fault planes are available and a uniform tensor is assumed, the scatter in the plane orientations contains information about both the relative position of ?2, represented by ?, and the relative stress difference, s: the higher s or the closer ? to either 0 or 1, the more scatter. This information could then be extracted by inverse methods. Because a friction law would constrain these inverse methods more tightly, it may show the necessity of non-uniform tensor to explain scattered fault planes.
A Conversation with Helen C. Spear: On Stress
(Hogg Foundation for Mental Health, 1981) Hogg Foundation for Mental Health
Discovery Of Ethanol-Responsive Small Rnas In Zymomonas Mobilis
(2014-07) Cho, Seung Hee; Lei, Roy; Henninger, Trey D.; Contreras, Lydia M.; Cho, Seung Hee; Lei, Roy; Henninger, Trey D.; Contreras, Lydia M.
Zymomonas mobilis is a bacterium that can produce ethanol by fermentation. Due to its unique metabolism and efficient ethanol production, Z. mobilis has attracted special interest for biofuel energy applications; an important area of study is the regulation of those specific metabolic pathways. Small RNAs (sRNAs) have been studied as molecules that function as transcriptional regulators in response to cellular stresses. While sRNAs have been discovered in various organisms by computational prediction and experimental approaches, their discovery in Z. mobilis has not yet been reported. In this study, we have applied transcriptome analysis and computational predictions to facilitate identification and validation of 15 novel sRNAs in Z. mobilis. We furthermore characterized their expression in the context of high and low levels of intracellular ethanol. Here, we report that 3 of the sRNAs (Zms2, Zms4, and Zms6) are differentially expressed under aerobic and anaerobic conditions, when low and high ethanol productions are observed, respectively. Importantly, when we tested the effect of ethanol stress on the expression of sRNAs in Z. mobilis, Zms2, Zms6, and Zms18 showed differential expression under 5% ethanol stress conditions. These data suggest that in this organism regulatory RNAs can be associated with metabolic functions involved in ethanol stress responses.
How Life Stressors Affect C-Reactive Protein and the Moderating Role of Education and Race/Ethnicity
(2018-04) Hamid, Hifza
How to Keep a Positive Mindset in the Face of Stress
(Burnt X Orange, 2019-03-21) Hyatt, Emily
Identification Of A Redox-Modulatory Interaction Between Uncoupling Protein 3 And Thioredoxin 2 In The Mitochondrial Intermembrane Space
(2011-11) Hirasaka, Katsuya; Lago, Cory U.; Kenaston, M. Alexander; Fathe, Kristin; Nowinski, Sara M.; Nikawa, Takeshi; Mills, Edward M.; Mills, Edward M.
Uncoupling protein 3 (UCP3) is a member of the mitochondrial solute carrier superfamily that is enriched in skeletal muscle and controls mitochondrial reactive oxygen species (ROS) production, but the mechanisms underlying this function are unclear. Aims: The goal of this work focused on the identification of mechanisms underlying UCP3 functions. Results: Here we report that the N-terminal, intermembrane space (IMS)-localized hydrophilic domain of mouse UCP3 interacts with the N-terminal mitochondrial targeting signal of thioredoxin 2 (Trx2), a mitochondrial thiol reductase. Cellular immunoprecipitation and in vitro pull-down assays show that the UCP3-Trx2 complex forms directly, and that the Trx2 N-terminus is both necessary and sufficient to confer UCP3 binding. Mutation studies show that neither a catalytically inactivated Trx2 mutant, nor a mutant Trx2 bearing the N-terminal targeting sequence of cytochrome c oxidase (COXMTS-Trx2) bind UCP3. Biochemical analyses using permeabilized mitochondria, and live cell experiments using bimolecular fluorescence complementation show that the UCP3-Trx2 complex forms specifically in the IMS. Finally, studies in C2C12 myocytes stably overexpressing UCP3 (2.5-fold) and subjected to Trx2 knockdown show that Trx2 is required for the UCP3-dependent mitigation of complex III-driven mitochondrial ROS generation. UCP3 expression was increased in mice fed a high fat diet, leading to increased localization of Trx2 to the IMS. UCP3 overexpression also increased expression of the glucose transporter GLUT4 in a Trx2-dependent fashion. Innovation: This is the first report of a mitochondrial protein-protein interaction with UCP3 and the first demonstration that UCP3 binds directly, and in cells and tissues with mitochondrial thioredoxin 2. Conclusion: These studies identify a novel UCP3-Trx2 complex, a novel submitochondrial localization of Trx2, and a mechanism underlying UCP3-regulated mitochondrial ROS production. Antioxid. Redox Signal. 15, 2645-2661.
Keeping Calm When You're on the Clock
(2018-10-31) Simon, Jeremy M.
Malleable Factors that Contribute to Teachers’ Stress, Burnout, Job Satisfaction, and Job Attrition in Special Education
(2020-10) Rodrigo, Saashya
The emotionally and physically taxing demands unique to the special education profession have been found to contribute to increased stress levels, thereby increasing the potential for teachers to experience burnout and job dissatisfaction. Namely, administrative tasks (increased paperwork and caseloads), lack of support and resources (inadequate teaching materials, lack of planning time, lack of administrative, parent, and peer teacher support), feelings of being under-prepared for the job, challenging behaviors exhibited by students, and inadequate reward for the efforts put in (low salary, lack of student progress), are a few factors that previous studies have linked to an increase in stress and burnout among special educators. Prolonged exposure to these factors may contribute towards teachers’ ultimate decision to leave the field of special education. Although previous systematic reviews have synthesized research on special education teacher attrition (Billinsley & Bettini, 2019; Billingsley, 2004; Brownell & Smith, 1992), and predictors of teacher stress and burnout (Brunsting et al., 2014; Fore et al., 2002; Wisniewski & Gargiulo, 1997), no systematic literature synthesis to date has specifically focused on malleable factors (i.e., factors that potentially can be changed or altered, unlike other variables such as teacher or student characteristics) and their relation to special educators’ stress, burnout, job satisfaction and job attrition. This literature synthesis aimed to address this research gap by systematically synthesizing existing studies that explored alterable factors such as work load, administrative support, self-efficacy, and job conflict and autonomy, and their correlation with teacher stress, job satisfaction, burnout, and attrition in special education.
Mindfulness and Early Childhood: A Developmental Neuroscience Perspective
(2021-05-11) Khanna, Prachi; Bryan, Amy; Schnyer, Rosa
Mindfulness-based interventions (MBIs) have become increasingly popular in K-12 settings, and many people have started exploring MBIs for use in early childhood settings—since brain development is so rapid during this developmental period. However, to date, there is no systematic review that explores existing research on MBIs in early childhood education. First, I provide an overview of brain development during early childhood, including the impact of environmental stressors. Next, I discuss mindfulness and related underlying brain processes. Finally, I summarize the literature on the use of MBIs in early childhood settings. Eleven studies are included in this review, and they are summarized around three outcome domains: self- regulation and executive functioning, academic performance, and socio-emotional well-being. Based on this small body of work, there appears to be strong evidence that MBIs are associated with the improvement of self-regulation and executive functioning in young children. There is modest evidence that MBIs impact socio-emotional well-being during early childhood, and there is limited evidence that MBIs improve the academic performance of young children. Characteristics of successful mindfulness interventions include common practices (e.g., movement activities, breathing exercises, mindfulness and the brain discussions, exercises pertaining to the five senses, and yoga), teacher facilitators, and long duration (twelve weeks or longer), with daily or near daily implementation.
Online Mindset Training Protects Adolescents from Unhealthy Responses to Stress
(University of Texas at Austin Population Research Center, 2022) Yeager, David S.; Bryan, Christopher J.; Gross, James J.; Murray, Jared S.; Krettek Cobb, Danielle; Santos, Pedro H.F.; Gravelding, Hannah; Johnson, Meghann; Jamieson, Jeremy P.
Relationship Between Radar Lineaments, Geologic Structure and in Situ Stress in East Texas
(1988) Baumgardner, Jr., Robert W.
Radar-based lineaments in East Texas and northwest Louisiana were studied to determine their relationship to surficial and subsurface geologic structure and to in situ stress. For all lineament data, two significant azimuths of vector sums were defined: 325° and 37°. The northwest trend has the same orientation as the mean direction of wellbore elongations in the Schuler Formation throughout the East Texas Basin. However, this trend is significantly different from the 344° orientation of wellbore elongation in the overlying Travis Peak Formation. These results suggest a complex relationship between subsurface stress and the northwest lineament trend. The northeast lineament trend does not coincide with the orientation of any known stress or regional structure and may be an artifact of radar illumination direction. Unlike a previous regional study based on smaller-scale Landsat data, no consistent correlation between surficial or subsurface structure and lineament density was discovered. However, high values of lineament density occur preferentially on outcrops of the Sparta and Leeches Formations. These results suggest that either most radar lineaments smaller than Landsat lineaments are manifestations of unmapped subregional or local structures or most radar lineaments are surficial phenomena, unrelated either to subsurface geologic structure or to stress.
Research + Pizza - Dr. Kimberly Burdine
(2016-09-08) Burdine, Kimberly
Diversity Coordinator Dr. Kimberly Burdine (Counseling & Mental Health Center) weaves research data and statistics into a discussion of coping skills and self-care for college students
TEM Measurements Of Grain Orientation In Nanoscale Cu Interconnects Using ACT
(2009-06) An, J. H.; Pickering, J.; Ganesh, K. J.; Ferreira, P. J.; An, J. H.; Pickering, J.; Ganesh, K. J.; Ferreira, P. J.
Transmission electron microscope (TEM) is used in conjunction with an Automated Crystallography for TEM (ACT) to index the crystal orientation of 180 nm wide Cu interconnects using the Nano Beam Diffraction (NBD) mode in the TEM. An FEM software, OOF2, was used to simulate the local quasi-hydrostatic stresses in the interconnect lines based on the local orientation data, and was compared results obtained from stress induced void (SIV) formation in 180nm Cu interconnects studied through in-situ TEM (Transmission Electron Microscope) heating. SIV were induced at temperatures of around 230 degrees C. Correlation between the stress simulations and the experimental results show that point of high local stresses and high stress gradients seem to influence the formation of the SIV in the Cu interconnect lines. A description of a new technique, called D-STEM that allows for obtaining diffraction patterns from crystals only a few nanometers in size is also given, that will allow for characterizing even smaller width Cu interconnects for future generation microelectronic devices.
The Theory Behind Camp Kesem: An In-Depth Look at How Summer Camp Programming Has Lasting Impacts on Children Affected by a Parent's Cancer
(2020-05) Iverson, Juliana
Camp Kesem is a national nonprofit dedicated to helping children through and beyond a parent's cancer. Children who have a parent with cancer face a multitude of difficulties and risks for adverse mental health affects. Four mediators were identified through previous research that are likely to help reduce the risks children with a parent with cancer face. Increases in self-esteem, coping skills, social support, and sense of community have all been linked to an increased likelihood of improving the mental health of individuals in stressful circumstances. There are established and researched intervention programs that are likely to increase these four mediators. The similarities of these researched intervention programs and Camp Kesem camp programming are explored to describe why Camp Kesem theoretically should increase these mediators in the children it serves. A survey for the counselors of Camp Kesem UT Austin was created to quanitatively and qualitatively assess if Camp Kesem does increase the four mediators of interest. Due to study limitations caused by COVID-19, the only mediator that could be unequivically show as probable as increasing was sense of community. Future research should be conducted in regard to the other three mediators and in the populations of the parents and campers that Camp Kesem serves.