University of Missouri

About: University of Missouri is a education organization based out in Columbia, Missouri, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 41427 authors who have published 83598 publications receiving 2911437 citations. The organization is also known as: Mizzou & Missouri-Columbia.

Faculty Members' Intentions to Leave: A National Study on Their Worklife and Satisfaction

Abstract: Despite the importance of faculty retention, there is little understanding of how demographic variables, professional and institutional worklife issues, and satisfaction interact to explain faculty intentions to leave at a national level. Using the National Study of Postsecondary Faculty (NSOPF:1999) database, this study proposes (a) to extend our previous conceptualization and understanding of those issues that comprise the dimensions of faculty worklife, satisfaction, and intentions to leave, (b) to examine relationships between these three dimensions, and (c) to determine the extent to which demographic variables and the quality of worklife have an impact on satisfaction, and faculty members' intentions to leave. Using structural equation modeling, the findings indicate that the perceptions faculty members have of their worklife have a direct and powerful impact on their satisfaction, and subsequently their intentions to leave. That is, a combination of worklife perceptions of faculty members' professional and institutional issues and satisfaction initiates individuals' behavioral intentions and the desire to leave for another position and/or career alternative.

Animal models of Duchenne muscular dystrophy: From basic mechanisms to gene therapy

Abstract: Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disorder. It is caused by loss-of-function mutations in the dystrophin gene. Currently, there is no cure. A highly promising therapeutic strategy is to replace or repair the defective dystrophin gene by gene therapy. Numerous animal models of DMD have been developed over the last 30 years, ranging from invertebrate to large mammalian models. mdx mice are the most commonly employed models in DMD research and have been used to lay the groundwork for DMD gene therapy. After ~30 years of development, the field has reached the stage at which the results in mdx mice can be validated and scaled-up in symptomatic large animals. The canine DMD (cDMD) model will be excellent for these studies. In this article, we review the animal models for DMD, the pros and cons of each model system, and the history and progress of preclinical DMD gene therapy research in the animal models. We also discuss the current and emerging challenges in this field and ways to address these challenges using animal models, in particular cDMD dogs.

Achieving Sustainable Gains in Happiness: Change Your Actions, not Your Circumstances*

Abstract: Although attaining happiness is a nearly universal goal, surprisingly little research has focused on how happiness can be increased and then sustained. Three studies test predictions of a model (Lyubomirsky et al., 2005) positing that sustainable happiness is possible through intentional activity changes, more so than through circumstantial changes. Study 1 shows that less hedonic adaptation is reported in response to activity changes than to circumstantial changes. Study 2 tests a dynamic process model, showing that while both positive activity changes and positive circumstantial changes predict rank-order increases in subjective well-being from Time 1 to Time 2, only activity changes predict maintained gains at Time 3. Study 3 replicates the Study 2 findings and extends them to psychological well-being (Ryff and Keyes, 1995). Implications for positive psychology and “the pursuit of happiness” are discussed.

Analysis of drainage-basin symmetry as a rapid technique to identify areas of possible Quaternary tilt-block tectonics: An example from the Mississippi Embayment

Abstract: There is a coincidence of seismicity and major river valleys in the southwestern Mississippi Embayment that suggests control of the drainage pattern by northwest-trending faults. Pleistocene river terraces reveal a strong southwestward preferred river migration in this region that may be a result of fault-block tilting. A rapid new technique of drainage-basin analysis is herein presented that quantifies transverse topographic basin symmetry. These data permit discrimination of random stream migrations and regionally preferred stream migrations and identify the direction of maximum migration. If bedrock dip can be shown to be a negligible influence on stream migration, then the direction of regionally preferred migration implies a period of ground tilting in that direction. Drainage-basin asymmetry vectors (bearing and degree of asymmetry) calculated from transverse topographic profiles of 271 4-km basin segments in the study area suggest preferred stream migration in response to west-southwest-ward ground tilting (bearing 259°). The eastward regional dip of bed-rock horizons only locally influences migration. River terrace distributions reveal a chronology of stream-migration episodes. Southwestward migration in the Ouachita, Saline, and Arkansas river basins occurred during early to middle Pleistocene time in the southwestern Mississippi Embayment. A Wisconsin/early Holocene southwestward migration episode is evidenced along southeast-flowing reaches of the Ouachita and Arkansas Rivers but not along the southeast-flowing reach of the intervening Saline River, suggesting that these rivers overlie separate northwest-trending tilt blocks. Although this technique does not provide direct evidence of ground tilting, it provides a quick-look method of identifying possible tilting elements in neotectonic regions using only topographic maps. This technique is of greatest utility where active faults are concealed or poorly exposed, such as in the Mississippi Embayment.

The role of surface charge on the uptake and biocompatibility of hydroxyapatite nanoparticles with osteoblast cells

Abstract: The objective of this study is to evaluate the effect of hydroxyapatite (HAP) nanoparticles with different surface charges on the cellular uptake behavior and in vitro cell viability and proliferation of MC3T3-E1 cell lines (osteoblast). The nanoparticles' surface charge was varied by surface modification with two carboxylic acids: 12-aminododecanoic acid (positive) and dodecanedioic acid (negative). The untreated HAP nanoparticles and dodecanoic acid modified HAP nanoparticles (neutral) were used as the control. X-ray diffraction (XRD) revealed that surface modifications by the three carboxylic acids did not change the crystal structure of HAP nanoparticles; Fourier transform infrared spectroscopy (FT-IR) confirmed the adsorption and binding of the carboxylic acids on the HAP nanoparticles' surfaces; and zeta potential measurement confirmed that the chemicals successfully modified the surface charge of HAP nanoparticles in water based solution. Transmission electron microscopy (TEM) images showed that positively charged, negatively charged and untreated HAP nanoparticles, with similar size and shape, all penetrated into the cells and cells had more uptake of HAP nanoparticles with positive charge compared to those with negative charge, which might be attributed to the attractive or repulsive interaction between the negatively charged cell membrane and positively/negatively charged HAP nanoparticles. The neutral HAP nanoparticles could not penetrate the cell membrane due to their larger size. MTT assay and LDH assay results indicated that as compared with the polystyrene control, greater cell viability and cell proliferation were measured on MC3T3-E1 cells treated with the three kinds of HAP nanoparticles (neutral, positive, and untreated), among which positively charged HAP nanoparticles showed the strongest improvement for cell viability and cell proliferation. In summary, the surface charge of HAP nanoparticles can be modified to influence the cellular uptake of HAP nanoparticles and the different uptake also influences the behavior of cells. These in vitro results may also provide useful information for investigations of HAP nanoparticle applications in gene delivery and intracellular drug delivery.