Plastic and evolved morphological responses of the hind limb skeleton to mechanical loading in mice

2018 ◽  
Author(s):  
◽  
Amanda Smolinsky
Keyword(s):  
Phenotypic Plasticity ◽  
Mechanical Loading ◽  
Hind Limb ◽  
Cross Sectional ◽  
Skeletal Morphology ◽  
University Of Missouri ◽  
Voluntary Running ◽  
Mechanisms Of Adaptation ◽  
The University ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Skeletal morphology is determined by a combination of genetic background and phenotypic plasticity induced by mechanical loading. The changes in limb bone morphology associated with locomotor activity through ontogeny and over evolutionary time can provide insight into the mechanisms of adaptation in locomotor systems. Here, a mouse model is used to explore the effects of mechanical loading and locomotor selection on skeletal morphology and phenotypic plasticity. The source of loading (muscular, ground reaction, or combined forces) was found to differentially affect the pattern and rate of mineral apposition at the mid-diaphysis of the femur, and the femoral cross-sectional morphology produced by running locomotion appears to be most influenced by muscular forces. Loading environment also differentially altered the gross shapes of the hind limb bones, and a blending of the influence of ground reaction and muscular forces was observed in the bones of running mice. Finally, artificial selection for increased voluntary running distance resulted in evolved changes in skeletal morphology and the plastic response of bone to mechanical loading. The results suggest regional sensitivity of skeleton to morphological change and inform our understanding of the plastic and evolutionary lability of the skeleton.

A lacanian reply to Marx : the necessity of topology in the formation of the social

2019 ◽  
Author(s):  
◽  
Lawrence Loiseau
Keyword(s):  
The Other ◽  
University Of Missouri ◽  
Other Hand ◽  
The Social ◽  
Social Link ◽  
True Source ◽  
The Subject ◽  
The One ◽  
The University ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] This study addresses Lacan's comments on Marx. While much has been done towards reading Marx with psychoanalysis generally, little had has been done to unpack the meaning and extent of Lacan's own statements on Marx. For example, while Lacanian Marxists like Slavoj Zizek have wielded Lacan to great effect in a critique of post-structuralism, they have neglected the full meaning and complexity of Lacan's own stance. What is argued thereby is that Zizek not only omits the discrete knowledge within Lacan's commentary, but misses what I describe as a Lacan's theory of the social. On the one hand, it is commonly known in Lacanian thought that discourse is responsible for making the subject. On the other hand, what is less known is that Lacan defined discourse as that which makes a social link which, in contrast with Marxist thought, introduces a certain affect and materialism premised on discourse itself, commonly known, but also for providing the underlying strata of topology (namely, paradox) requisite for making any social link between subjects. Although less commonly known, we can nevertheless gain new insight into Marx. On the one hand, Lacan concedes Marx's underlying structuralism. On the other hand, Marx fails to see the true source of discourse's origins, the real itself, and consequently fails to see the true efficacy of discourse. He fails to see how discourse, although negative, stands as entirely positive and material in its distinctive effects. Discourse negotiates subjects and their inimitable objects of desire in this singularity itself. This is where true production lies; it is that which precedes any social or economic theory, which are otherwise premised on reality. Lacan rejects reality.

We have a duty to eradicate HIV in the community, in the world' : successful PrEP use among black men who have sex with men

2020 ◽  
Author(s):  
◽  
Laura Remy
Keyword(s):  
Black Men ◽  
The United States ◽  
University Of Missouri ◽  
Individual Interviews ◽  
Biomedical Prevention ◽  
Sex With Men ◽  
One Year ◽  
Exposure Prophylaxis ◽  
The University ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Black men who have sex with men (BMSM) have a 50% lifetime risk of HIV infection. The HIV epidemic continues to be a perplexing health issue, despite the availability of a highly effective biomedical prevention strategy. Pre-exposure prophylaxis (PrEP) uptake is suboptimal among BMSM: a priority population that accounts for over one fourth of all new HIV diagnoses in the United States. Most research endeavors have focused on identifying barriers to PrEP with less emphasis on facilitators of PrEP uptake. This qualitative study was undertaken to gain a better understanding about the factors that motivate BMSM to seek PrEP and the strategies that resulted in successful uptake. In-depth individual interviews were conducted with Midwestern BMSM (n=12) who were successfully taking PrEP for over one year. The men were sophisticated, privately insured healthcare consumers and yet, the overarching theme that emerged from the data was that obtaining PrEP was a "long, hard road". Facilitators to PrEP access included having an important person, insight into the roles of stigma, sexual partner mistrust, and the desire to be a part of something bigger than oneself. Also prevalent in the data were descriptions about barriers to PrEP access. Men in this study felt strongly that HIV prevention is everyone's responsibility. Findings have important implications for research and clinical practice. Strategies that can decrease healthcare system barriers and help simplify the process to access PrEP are greatly needed.

Metadrama in the chorus : the first choral ode of Seneca's Oedipus

2016 ◽  
Author(s):  
◽  
Maria Silvia Sarais
Keyword(s):  
Literary Criticism ◽  
Main Topic ◽  
Apparent Discrepancy ◽  
University Of Missouri ◽  
Level Of Significance ◽  
The University ◽  
Verbal Analysis ◽  
Artistic Skill ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The main topic of this dissertation is the first choral ode of Seneca's Oedipus. Seneca's handling of the choral parts has often suffered from negative criticism, mainly due to the fact that often, at first glance, the interventions of the chorus seem to not be an integral part of the play. For this reason, Seneca's choral odes have often been considered a mere display of the poets' rhetorical abilities, frequently dismissed as lyrical evasions, and occasionally even charged with being at odds with the context in which they are inserted. These types of assessments have been conducive to negative evaluations of Seneca's handling of the chorus, and of his dramatic competence, and have often been used to support the argument that Seneca's tragedies were not intended to be staged. My analysis shows that Seneca's variation of the poetic sources is never meaningless for the dramatic context, and argues that the chorus is an integral part of the play, one that is essential to fully understand and appreciate Seneca's dramatic art. By combining an intertextual approach and verbal analysis, I show that omissions, additions, and variations lead the audience to see the first ode as a symbolic account of Oedipus' destiny, one that prefigures the ways in which the tragic narrative is about to develop, and that prepares the audience to recognize the ways in which Seneca's poetic rewriting of Oedipus' myth is going to be original. The ode, in fact, displays the presence of a language that is highly ambiguous and multireferential, and that draws on the technical language of literary criticism and of programmatic statements of poetics. This language permits the audience to detect a meta-dramatic level of communication in the ode, one where Oedipus is characterized as a surrogate of the tragic poet. The final chapter provides evidence of the fact that all of the remaining odes display the same polysemous language that continues to sustain a meta-dramatic level of significance. My study shows that a recognition of metadrama in the odes is important in several ways. It increases the tragic irony. It complicates traditional notions of tragic fate, thereby providing an explanation for the apparent discrepancy between Seneca the Philosopher and Seneca the Tragedian that does not see the tragedies as the result of Seneca's retraction of his Stoic ideas. It offers an insight into Seneca's tragic poetics, while pointing to a possible reconciliation between Callimachean artistic skill and Bacchic inspiration. Finally, it points to a particular type of expected audience, one that is rational, literarily well-educated, and hence able to recognize all of the subtleties of the poets' sophisticated poetic enterprise.

Rats selectively-bred for low and high voluntary running: co-selected traits and the effects of voluntary running on the dentate gyrus transcriptome

2014 ◽  
Author(s):  
◽  
Jacob Daniel Brown
Keyword(s):  
Physical Activity ◽  
Locomotor Activity ◽  
Dentate Gyrus ◽  
Selective Breeding ◽  
Drugs Of Abuse ◽  
Wheel Running ◽  
University Of Missouri ◽  
Voluntary Running ◽  
The University ◽  
Physical Activity Motivation

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The Booth lab at the University of Missouri has selectively-bred Wistar rats for low (LVR) and high (HVR) voluntary running behavior as a model for examining the genetic and physiological origins of physical activity motivation. The major advantage of selective breeding over non-natural methods of genetic engineering is the perpetuation of naturally-existing, polygenic milieus that dictate complex behaviors or phenotypes (e.g. motivation to be physically active, etiology of obesity). Since most genes and physiological systems are pleiotropic and function as modular networks, a "by-product" of selective breeding is the co-selection of traits sharing some common genetic origins with the selected trait. Overall, the major emphasis of my dissertation was two-fold: (1) the elucidation of behavioral traits co-selected with low and high physical activity motivational behavior and (2) the effect of voluntary running in a mildly stressful environment on the dentate gyrus transcriptome of rats selectively bred for low voluntary running. Emphasis 1 (Chapters 2 and 3) was approached by measuring the performance of LVR and HVR rats in behavioral tests classically designed to measure non-wheel running locomotor activity behavior (i.e. open field test), sensitivity to drugs of abuse (i.e. cocaine-induced locomotor activity), anxiety-like behavior (i.e. elevated plus maze), depressive-like behavior (i.e. forced swim test), and nociception (i.e. thermal and mechanical stimulus). Emphasis 2 was approached by using RNA sequencing (RNA-seq) to map the transcriptome of the dentate gyrus after exposing sedentary and wheel running LVR and WT rats to 5 weeks of chronic mild stress (CMS). The results from Chapters 2 and 3 demonstrate that LVR and HVR rats have co-selected other behaviors, which suggest that they may be a valuable model for an array of research disciplines including: (1) the investigation of the genetic basis for physical activity motivation, (2) hyperactivity, (3) sensitivity to drugs of abuse (e.g. addiction), (4) emotional/stress disorders (e.g. anxiety and depression), and (5) nociception as well as the interactions between these complex phenotypes. The results from Chapter 4 provide transcriptomic evidence that low amounts of voluntary running performed by female LVR rats in a CMS environment are sufficient for eliciting robust changes in dentate gyrus transcriptome that included gene expression signatures associated with elevated synaptic plasticity, improved memory function, and increased blood vessel development.

scholarly journals Synergist ablation induces rapid tendon growth through the synthesis of a neotendon matrix

2014 ◽  
Vol 117 (11) ◽  
pp. 1287-1291 ◽  
Author(s):  
Jonathan P. Gumucio ◽  
Anthony C. Phan ◽  
David G. Ruehlmann ◽  
Andrew C. Noah ◽  
Christopher L. Mendias
Keyword(s):  
Mechanical Loading ◽  
Type I Collagen ◽  
Fluorescent Microscopy ◽  
Type I ◽  
Fibroblast Cells ◽  
Cellular Mechanisms ◽  
Fast Green ◽  
Cross Sectional ◽  
Plantaris Tendon ◽  
Insight Into

Mechanical loading can increase tendon cross-sectional area (CSA), but the mechanisms by which this occurs are largely unknown. To gain a greater understanding of the cellular mechanisms of adult tendon growth in response to mechanical loading, we used a synergist ablation model whereby a tenectomy of the Achilles tendon was performed to induce growth of the synergist plantaris tendon. We hypothesized that after synergist ablation progenitor cells in the epitenon would proliferate and increase the size of the existing tendon matrix. Adult male mice were subjected to a bilateral Achilles tenectomy, and plantaris tendons were isolated from mice at 0, 2, 7, 14, and 28 days after surgery. Tendons were sectioned stained with either fast green and hematoxylin, prepared for fluorescent microscopy, or prepared for gene expression of scleraxis and type I collagen. After overload, there was a dramatic increase in total CSA of tendons, whereas the size of the original tendon matrix was not changed. Growth primarily occurred through the formation of a neotendon matrix between the original tendon and the epitenon, and contained cells that were proliferative and scleraxis positive. Additionally, an initial expansion of fibroblast cells occurred before the synthesis of new extracellular matrix. Fibroblasts in the original tendon did not re-enter the cell cycle. The results from this study provide new insight into the mechanisms of tendon growth, indicate tendon consists mostly of postmitotic cells, and that growth of tendon primarily occurs from the most superficial layers outward.

Autophagy and ubiquitin-proteasome system during post-fertilization sperm mitophagy

2016 ◽  
Author(s):  
◽  
Won-Hee Song
Keyword(s):  
Membrane Proteins ◽  
Mitochondrial Membrane ◽  
Ubiquitin Proteasome System ◽  
Major Protein ◽  
University Of Missouri ◽  
Mammalian Sperm ◽  
Ubiquitin Binding ◽  
Ubiquitin Proteasome ◽  
The University ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Maternal inheritance of mitochondria and mitochondrial DNA (mtDNA) is a universal principle in developmental biology. Mammalian sperm-borne mitochondria are selectively degraded inside the fertilized oocyte. Our early observations established that post-fertilization degradation of sperm mitochondria is mediated by ubiquitin-proteasome system (UPS), the major protein-turnover pathway that degrades proteins one molecule at a time. Others' recent studies suggested that a whole organelle sperm mitochondrion is degraded by autophagic pathway, which is referred to as sperm mitophagy. Based on this understanding, the first objective of this dissertation was to identify UPS determinants present in porcine sperm mitochondria. The second objective was to characterize the UPS-controlled porcine ooplasmic autophagy receptors that may regulate sperm mitophagy after fertilization. The interaction between UPS and autophagic pathway was revealed during post-fertilization sperm mitophagy. It was determined that the ooplasmic, ubiquitin-binding autophagy receptor SQSTM1 binds to ubiquitinated mitochondrial membrane proteins, targeting whole mitochondria towards autophagosome. Concurrently, protein dislocase VCP extracts ubiquitinated mitochondrial membrane proteins and transport them to proteasome. Collectively, these studies offer insight into the mechanisms guiding sperm mitochondrion recognition and disposal after fertilization, which assure normal preimplantation development and prevent a potentially detrimental effect of heteroplasmy.

Methamphetamine-induced hyperactivity and reinforcement learning in rats selectively bred for high and low voluntary running

2015 ◽  
Author(s):  
◽  
Andrew S. Sage
Keyword(s):  
Wheel Running ◽  
Food Pellet ◽  
Preliminary Investigation ◽  
Voluntary Exercise ◽  
University Of Missouri ◽  
Voluntary Running ◽  
Lever Pressing ◽  
Necessary And Sufficient ◽  
The University

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The goal of the present research was to assess two lines of Wistar rats selectively bred for high (HVR) and low (LVR) voluntary wheel running, in comparison to a line of control (WT) rats. As previous research has outlined the benefits of voluntary exercise on substance abuse, this study investigated the role of possible genetic differences between rat lines on sensitivity to methamphetamine (Experiment 1), motivation to work for and self-administer methamphetamine (Experiment 2a), and learning to press a lever for a food reward (Experiment 2b). Experiment 1 investigated sensitivity to methamphetamine in HVR, LVR, and WT rats by comparing locomotor behavior after methamphetamine administration. Experiment 1 found that both HVR and LVR rats were less sensitive to the locomotor activating properties of methamphetamine compared to WT rats. Experiment 2a and 2b investigated learning to press a lever for a food pellet or an infusion of methamphetamine in HVR, LVR, and WT rats. Experiment 2a found that both HVR and LVR rats were less sensitive to the reinforcing properties of methamphetamine compared to WT rats, evidenced by their reduced lever pressing behavior. Experiment 2b found that HVR rats pressed a lever less for a food pellet compared to both LVR and WT rats, suggesting that HVR rats alone may value a food pellet as a behavioral reinforcer less than the other two rat lines. The results of this preliminary investigation suggest that exercise may be both necessary and sufficient to produce effects on drug use behaviors. One's (genetic) predisposition to engage in exercise may be independent of one's ability to benefit from exercise.

No crown without the cross : the formation, existence, and disappearance of the Catholic Stage Guild of Ireland

2015 ◽  
Author(s):  
◽  
Lauren Alexandra Iben Cahill
Keyword(s):  
Twentieth Century ◽  
Research Question ◽  
Historical Context ◽  
Irish Nationalism ◽  
Irish Theatre ◽  
University Of Missouri ◽  
The Status ◽  
Irish Catholics ◽  
The University ◽  
Insight Into

[ACCCSS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] In December 1948, an article by Seamus Brady in The Manitoba Ensign claimed, "[The Catholic Stage Guild of Ireland] has branches in every city in Ireland, as well as in Britain, America and Australia." Its presence, according to Brady's article, was overwhelming. And yet by the 1970s, the Guild mysteriously seemed to disappear altogether from Irish society. This popularity and disappearance formulated my dissertation's primary research question: how did the life of the Catholic Stage Guild of Ireland (its birth, success, and disappearance) reflect twentieth century Irish Catholicism and its relationship with the nation? This question encouraged numerous subsidiary questions including: how was the Guild as popular as Brady claims? And if it indeed was as Brady claims, then why did it extinguish? This dissertation seeks to uncover whether the Catholic Stage Guild of Ireland's seemingly short, but powerful years emulating the status and movements of Irish Catholicism in the twentieth century The Catholic Stage Guild of Ireland dramatically depicted the heartaches and successes of the Irish Catholics. Created by firm Catholics during a time in which the religion was celebrated, then altered, then slandered, the Catholic Stage Guild offers insight into individual attitudes concerning the state of the country and its primary religion. A study of the Catholic Stage Guild (which until now has not been conducted) will not only examine the history and purpose of this group of Catholic artists, but also falls in the foreground against the backdrop of twentieth century Ireland and provides insight into the movements of Irish Catholicism and nationalism during this time. Ultimately, this dissertation provides a historical context for Catholics to understand the relationship between Irish Catholicism, Irish nationalism and Irish theatre in the twentieth century, as well as provides non-Catholics with a sense of the importance of a Catholic Stage Guild in a time consumed by religious conflict.

Simulation aided analysis of polyurethane reaction systems

2015 ◽  
Author(s):  
◽  
Rima Ghoreishi
Keyword(s):  
Experimental Data ◽  
Foam Height ◽  
Polymerization Process ◽  
Gel Point ◽  
University Of Missouri ◽  
Reaction Systems ◽  
Reaction Proceeds ◽  
The University ◽  
Kinetics Of ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Numerous reactions take place within a polyurethane polymerization process. Homogeneous and catalytic reactions occur at the same time and intermediate compounds are formed. As the reaction proceeds, long chains of polymer are formed which drastically affect the kinetics of the reaction. Temperature and viscosity profiles of the reacting mixture are two strong indicators of the extent of reaction and the way the reactions are carried out. Therefore, simulating polyurethane gel and foam systems helps interpret temperature and viscosity profiles and gain insight into the kinetics of the system. Using MATLAB program, a model was introduced which simultaneously solves over 80 ordinary differential equations and provide temperature and viscosity profiles as well as concentration profiles, degrees of polymerization, gel point and foam height for individual formulations. Experimental data was used to validate the code showing the model is fundamentally correct. Simulation results showed good fits to the experimental data providing reaction kinetics of the system. The model was modified to simulate reaction systems with minimal change in kinetic parameters. The model successfully simulates polyurethane polymerization process for both bio-based and petroleum-based polyols. A different version of the code also simulates the formation of bio-based polyols from epoxidized soybean oil.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

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