Louisiana State University

    Integrin bi-directional signaling across the plasma membrane

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    Integrins are heterodimeric cell adhesion molecules that are important in many biological functions, such as cell migration, proliferation, differentiation, and survival. They can transmit bi-directional signals across the plasma membrane. Inside-out activating signal from some cell surface receptors bound with soluble agonists triggers integrins conformational change leading to high affinity for extracellular ligands. Then binding of ligands to integrins results in outside-in signaling, leading to formation of focal adhesion complex at the integrin cytoplasmic tail and activation of downstream signal pathways. This bi-directional signaling is essential for rapid response of cell to surrounding environmental changes. During this process, the conformational change of integrin extracellular and transmembrane/cytoplasmic domains is particularly important. In this review, we will summarize recent progress in both inside-out and outside-in signaling with specific focus on the mechanism how integrins transmit bi-directional signals through transmembrane/cytoplasmic domains. © 2012 Wiley Periodicals, Inc

    Developmental Math Education: The Bermuda Triangle of Student Success--Many Enter, but Few Succeed.

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    This study employed a quantitative design to evaluate the effectiveness of developmental math and the predictors of student success in developmental math for a period of three years. Four of the study’s original eight predictors of student success were statistically significant. However, a model was created using multinomial regression. The model was created using data from the fall 2013 semester and was tested using data from the fall 2014 semester. The effectiveness of developmental math in predicting a student’s success in the first college-level math course was tested using a multinomial regression. Although no statistical significance was found, the study did show that students who completed developmental math prior to enrolling in a college-level math course were more likely to earn passing grades. Implications for community college policy, practice, and future research are presented

    Regarding Suicide: A Textually Informed Rhetorical and Psychoanalytic Construct of the State of Disconstituency, Disconstitutive Rhetoric, and the Disconstituent as Related to the Constitutive Rhetorical Structure of the Vanishing Subject

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    Suicide contagion is a real phenomenon. The stigmatization of suicide attempters, completers, survivors of suicide loss, and the idea of suicide itself is at least partly to blame for these outbreaks. Regarding suicide as an analyst, journalist, witness, responder, or bereaved family member or friend can be a devastating form of metaphorical and literal looking. Through a psychoanalytic understanding of constitutive rhetoric, this dissertation offers a textualized way of considering the difficult process of giving individuals who have completed suicide one’s regard. Beyond just suicide, this rhetoric of regard presents the disconstituent as the lost persona that withdraws from identification practices. In so doing, this work offers a methodology which articulates the painting technique known as the “vanishing point” through the Lacanian subject positions of the Imaginary, Symbolic, and Real. This dissertation argues that identification can be understood as a demand for a false confession of a subject that does not really exist through Kenneth Burke’s notion of “the negative” and “self-abnegation.” The disconstituent is the persona lost to and by the subjective practices of identification. Disconstitutive rhetoric is the false confession and interrogation that creates the state of disconstituency which resides within the regarded disconstituent. This dissertation concludes by arguing for an ambivalent regard which mirrors the disconstituent withdrawal while still allowing for the one regarding to feel for the regarded

    Mothers Grimm and Other House Held Tales

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    Mothers Grimm and Other House Held Tales is a body of work that uses fairy tale archetypes and narrative traditions to comment upon tensions and conflicts in sexual self-understanding. This is achieved through a reflection on attitudes that women adopt regarding their own sexuality. Such a reflection is instigated through a presentation of prominent cultural archetypes that exist, no longer as received ideas, but as a bold and entertaining expression of how sex can change our attitude towards those ideas that we often take for granted. Through an assemblage of objects and video, this body of work evokes a domestic setting through the re-creation of the household environment. The viewer is drawn in by fun looking characterizations that, upon first glance, arouses a sense of archetypal nostalgia. However, a closer investigation reveals sardonic humor and associative metaphors that refer to sexual themes, some situated in dark places

    Factors influencing the spatial distribution of natural resource-based industries: the softwood lumber industry in the United States South

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    Expanding on the Theory of Location, New Economic Geography, and Porter\u27s Theory of Clusters this dissertation attempts to identify key factors influencing the location of firms in a resource-based industry. The softwood lumber industry in the United States is used as a case study to test several hypotheses concerning these theories. Two U.S. regions, the West and the South, were selected for analysis because they account for over 70 percent of U.S lumber manufacturing capacity. A multi-disciplinary research approach involved three-stages. First, self-reported preferences were analyzed using common factor and conjoint analyses for preferences for location attributes. Surveys were sent to all sawmill managers in the U.S. West and South regions. Respondents were identified through the Random Lengths\u27 Big Book (2006), the industry\u27s most comprehensive database. Survey procedures followed Dillman\u27s (2000) Tailored Design Method. Conjoint analysis provided information on the relative importance of selected site attributes using several econometric models to estimate coefficients, significance and marginal effects of site attributes. Second, a model for industry location behavior in the U.S. South was developed using a spatial econometric model. An exploratory analysis identified deviations from complete spatial randomness as first-hand evidence of clustering. The presence of sawmill enterprises was used as the dependent variable, aggregated at the county level. Spatial autoregressive and correlated error econometric models were used to correct for spatial correlation. The final model was used to identify counties where softwood lumber industry development could occur in the future with a high probability of success. Third, two cross-sections of data were analyzed using point density tools to explore spatial concentration in the softwood lumber industry over time. There is evidence of consolidation in the industry as the number of firms has declined while capacity has increased over time. The findings are congruent with spatial predictions drawn by Location Theory, New Economic Geography and to some extent the Theory of Clusters. Research methods used in this study have the ability to capture decision-makers preferences and to operationalize major theories of location, economic geography and cluster development. Results can provide industry and economic development professionals with a new decision-making tool

    Characterization of porcine adipose tissue-derived stem cells

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    Nuclear transfer (NT) results in low success rates and research has reported problems with the welfare of cloned animals produced. Evidence suggests the use of a less differentiated donor cell, such as a stem cell, may lead to an increase in the efficiency of the NT procedure. Stem cell characteristics must be clearly defined in order to isolate, identify and optimally culture potential donor cells. Stem cell characteristics such as self-renewal and differentiation have not been identified in stem cells from porcine adipose tissue, an easily attainable tissue resource. The phenotypic profile of cell surface proteins and chromosomal stability of porcine adipose tissue-derived stem cells (pASCs) through in vitro culture have not been described. Also, research has not identified epigenetic modifications in adult somatic mesenchymal stem cells (MSCs) from porcine adipose tissue. The objective of Project 1 was to develop a protocol for the isolation and culture of pASCs and to determine stem cell-like characteristics. The objective of Project 2 was to characterize the surface protein phenotype of undifferentiated porcine ASCs and to determine the chromosomal stability through in vitro culture. The objective of Project 3 was to analyze pASCs and compare them to fetal porcine fibroblasts (FPF) for gene expression profiles of chromatin remodeling proteins, global methylation and acetylation patterns and methylated lysine residues within promoter regions of developmentally important transcription factors. Improved culture conditions and defined cellular characteristics of these pASCs have been identified. pASCs can self-renew and differentiate into multiple tissue lineages. Porcine ASCs do not express the stem cell surface markers analyzed at similar levels compared with those of human ASCs reported in the literature. Also, in vitro-cultured porcine ASCs used as donor cells for NT should be chosen from early population doublings (PDs) due to increased levels of aneuploidy at later PDs. Further characterization of porcine ASCs in this manner could assist the isolation and purification of a population of MSCs from the easily obtainable tissue of adipose that can later be tested as donor cells in nuclear transfer

    The use of classroom demonstrations to improve high school students\u27 ability to understand concepts in chemistry

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    This study was completed to determine if implementing demonstrations in specific chapters of a high school chemistry classroom would enhance students understanding of the topics the demonstrations represented. The study consisted of five sections of college preparatory high school chemistry. The sections were made up of both male and female students. The sections were randomly broken up into two groups. Each group acted as the experimental and control at different points in the study. Four chapters were used in the study. Each group represented the control group in two chapters and the experimental group in two chapters, flip flopping with each chapter tested. Both groups were given a pre-test at the start of the chapter to assess prior knowledge. The experimental group was provided with classroom demonstrations throughout the chapter along with a standard lecture on the topics tested in the pre-test. The control group was given a standard lecture but was not shown any demonstrations throughout the chapter. Both groups were given a post-test to evaluate understanding gained at the end of the chapter. No significant differences were observed between the control and experimental groups when comparing raw test scores. However, a consistent trend was observed suggesting that the demonstrations presented to the experimental group did have a positive effect on student understanding with those students obtaining higher learning gains than those without the demonstrations. In comparison of normalized learning gains between the control and experimental groups, a trend of increased normalized learning gain for the experimental groups was observed including statistical significance in two of the chapters tested. The data collected was also broken down by gender with-in each chapter. No statistical significance was found in the raw scores or normalized learning gain based on gender

    Developmental responses to abiotic conditions during aquatic and air incubatoin of the Gulf killifish (Fundulus grandis): subtitle

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    The Gulf killifish (Fundulus grandis) is a topminnow native to the tidal marshes of the Gulf of Mexico. The species is prized by anglers as effective bait for catching popular sportfish and is of interest to aquaculturists and bait dealers due to its hardy nature. Limited seasonal availability and aquaculture of this species due to low fecundity and larval cannibalism of fry has led to increased incentive to improve cultural techniques. The purpose of this study is to determine the influences of temperature, salinity, and air incubation on embryogenesis of the Gulf killifish. Temperature was found to have a negative relationship with time to hatch and size at hatch when F. grandis eggs were incubated in 10 and 20 g/L saline treatments. Temperature did not significantly affect percent hatch at 10 g/L, but percent hatch displayed a positive relationship with temperature at 20 g/L. When incubated in 0.4, 7, 15, and 30 g/L salinity treatments, a negative relationship between salinity and rate of embryogenesis was detected. While larvae incubated in these salinities hatched at about the same size, reduced hatching percentages were reported in the 0.4 and 30 g/L treatments. A positive relationship between the rate of embryogenesis and temperature was observed in air incubated embryos. After reaching a stage of development when embryos are documented to hatch, temperature was observed to have a negative relationship with the extent of time hatch could be delayed. The results of this study can be used to improve culture practices for Gulf killifish. Larval size at hatch, percent hatch, and time to hatch can now be predicted across a range of temperatures and salinities. Warmer temperatures can be used to accelerate embryogenesis of air incubated embryos while colder temperatures can be used to extend the period of time hatch can be delayed

    Physical activity and health-related quality of life among elementary students: an integrated perspective

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    School physical education (PE) not only offers and promotes health-related physical activity, but also encompasses the promotion and development of perceptions of mental health (USDHHS, 2010). It has been suggested that health-related quality of life (HRQOL) can predict future health, monitor children’s psychosocial health, and identify those most at risk or in need of support at an early stage. Assessing physical activity (PA) and health-related quality of life have become major issues in pediatric public health and also serve as a major goal of Health people 2020 (USDHHS, 2010). Research including assessment of theory-based mediators of health-related outcomes is needed (Ryan, Patrick, Deci, & Williams, 2008). Grounded in the expectancy-value (Eccles., 1983) and achievement goal (Ames, 1992a, 1992b) frameworks, the primary purpose of this study was to examine the relationships among the perceptions of motivational climate in PE, expectancy-value beliefs, intention to participate in PE, HRQOL, and PA among elementary children. A secondary purpose was to examine gender and racial differences in students’ motivation in physical education, intention, HRQOL and PA. Participants were 336 elementary school physical education students from three schools in the southeast US. They completed surveys and wore pedometers during three days of physical education classes. The findings support the assertion that children with higher expectancy beliefs were more likely to be physically active and report higher HRQOL than those with low levels of expectancy beliefs. Perception of a mastery motivational climate together with positive expectancy beliefs could be an advantage for physical and psychosocial health among children in this study, whereas perception of a performance motivational climate was associated with less physical activity (i.e. lower steps/min) during PE even if students view PE as important, interesting and useful. There were gender and race differences on children’s motivation, HRQOL and PA during PE, which suggests that interventions aimed at preventing physical inactivity and developing optimal mental health should be tailored to individual needs in light of those differences. This research may provide useful information on the translation of theory to practice designed to influence children’s health perceptions and behaviors

    Spectral analysis of stop consonants in individuals with dysarthria secondary to stroke

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    Dysarthria refers to a group of neurogenic speech disorders which result in abnormal strength, speed, range, steadiness, tone, or accuracy of movements required for speech production. Although speech deficits of dysarthria are heterogeneous according to lesion sites and/or etiologies such as stroke, traumatic brain injury, cerebral palsy, Parkinson’s disease (PD), “imprecise consonants” has been known as one of the most prominent and frequently occurring features of dysarthria, which subsequently contributes to decreased speech intelligibility. The present study points out the paucity of acoustic data on consonants produced by speakers with dysarthria, especially by spectral analysis, and reports four spectral moment analysis results on word initial stop consonants in six individuals with dysarthria and six age and gender matched healthy individuals. Each participant was asked to say a series of single words with a carrier phrase and a set of sentences. The initial 40ms of each single word was analyzed using TF32 to find the spectral moment values. Results suggest that the first spectral moment (M1) was the most useful in differentiating between the genders, healthy vs. dysarthria, and place of articulation, which is consistent with previous studies. This moment revealed that individuals with dysarthria have higher values compared to healthy individuals, which indicates that this speaker group tends to have a more anterior constriction for stop production. Along with this fronting pattern, the M1 ratios between adjacent stops were reduced for the speakers with dysarthria, which indicates reduced acoustic contrast for stop production. However, no correlation was found between the perceptual speech intelligibility estimates and the spectral characteristics
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