Composition of fluid inclusions from the cave-in-rock bedded-replacement fluorite deposits in the Illinois-Kentucky district

Title from PDF of title page (University of Missouri--Columbia, viewed on May 23, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Martin AppoldIncludes bibliographical references."July 2011"The stable mid-continent platform of North America hosts some of the greatest known concentrations of Mississippi Valley-type (MVT) mineralization in the world. Most of the mineralization occurs between two major physiographic regions, the Ozark Plateau and the Interior Low Plateau. The Illinois-Kentucky district is one of three principal MVT districts in the Interior Low Plateau and is distinct from other North American mid-continent MVT deposits in that its ore mineral assemblage is dominated by fluorite instead of sulfide minerals or barite. However, like these other MVT deposits, the Illinois-Kentucky deposits were probably precipitated from northward flowing sedimentary brines set in motion by topographic gradients created by the Alleghanian-Ouachita orogeny during the Late Paleozoic. The primary objective of the current study was to quantify the chemical composition of the mineralizing fluids through in situ fluid inclusion analysis using microthermometry, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), and laser Raman spectroscopy in order to try to gain insights into the ore formation process. Results show that the fluids that formed the Illinois-Kentucky district are chemically distinct from the fluids that formed MVT deposits in the Ozark Plateau. These differences can be attributed to interaction of the mineralizing sedimentary brines with ultramafic, rift-related igneous rocks present in the Illinois-Kentucky district but not in any of the Ozark Plateau districts. Fluid inclusion homogenization temperature and salinity relationships suggest that MVT mineralization in the Illinois-Kentucky district was produced from a mixture of at least three brines, two of which had relatively high salinities and temperatures and the third of which was cooler and more dilute. Mixing among at least three fluids is supported by the elemental concentration data, which tend not to correlate with one another or with the microthermometry data, but rather plot as two-dimensional arrays. The compositions of the end member fluids could not be pinpointed from the available data, however it appears that at least one of the fluids had elevated concentrations of the ore metals, Pb, Zn, Cu, and Fe as high as on the order of 1000's of ppm

Potential Developmental and Reproductive Impacts of Triclocarban: A Scoping Review

Triclocarban (TCC) is an antimicrobial agent used in personal care products. Although frequently studied with another antimicrobial, triclosan, it is not as well researched, and there are very few reviews of the biological activity of TCC. TCC has been shown to be a possible endocrine disruptor, acting by enhancing the activity of endogenous hormones. TCC has been banned in the US for certain applications; however, many human populations, in and outside the US, exhibit exposure to TCC. Because of the concern of the health effects of TCC, we conducted a scoping review in order to map the current body of literature on the endocrine, reproductive, and developmental effects of TCC. The aim of this scoping review was to identify possible endpoints for future systematic review and to make recommendations for future research. A search of the literature until August 2017 yielded 32 relevant studies in humans, rodents, fish, invertebrates, and in vitro. Based on the robustness of the literature in all three evidence streams (human, animal, and in vitro), we identified three endpoints for possible systematic review: estrogenic activity, androgenic activity, and offspring growth. In this review, we describe the body of evidence and make recommendations for future research

Establishing Biomechanical Mechanisms in Mouse Models: Practical Guidelines for Systematically Evaluating Phenotypic Changes in the Diaphyses of Long Bones

Mice are widely used in studies of skeletal biology, and assessment of their bones by mechanical testing is a critical step when evaluating the functional effects of an experimental perturbation. For example, a gene knockout may target a pathway important in bone formation and result in a “low bone mass” phenotype. But how well does the skeleton bear functional loads; eg, how much do bones deform during loading and how resistant are bones to fracture? By systematic evaluation of bone morphological, densitometric, and mechanical properties, investigators can establish the “biomechanical mechanisms” whereby an experimental perturbation alters whole‐bone mechanical function. The goal of this review is to clarify these biomechanical mechanisms and to make recommendations for systematically evaluating phenotypic changes in mouse bones, with a focus on long‐bone diaphyses and cortical bone. Further, minimum reportable standards for testing conditions and outcome variables are suggested that will improve the comparison of data across studies. Basic biomechanical principles are reviewed, followed by a description of the cross‐sectional morphological properties that best inform the net cellular effects of a given experimental perturbation and are most relevant to biomechanical function. Although morphology is critical, whole‐bone mechanical properties can only be determined accurately by a mechanical test. The functional importance of stiffness, maximum load, postyield displacement, and work‐to‐fracture are reviewed. Because bone and body size are often strongly related, strategies to adjust whole‐bone properties for body mass are detailed. Finally, a comprehensive framework is presented using real data, and several examples from the literature are reviewed to illustrate how to synthesize morphological, tissue‐level, and whole‐bone mechanical properties of mouse long bones. © 2015 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111801/1/jbmr2539.pd

Impacts of food contact chemicals on human health: a consensus statement

Food Packaging Forum Foundation (FPF) and the Plastics Solution Fund (PSF

The contribution of the nursery school lunch to recommended nutrient allowances of twenty-one preschool children at the University of Arizona

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Gendered differences in academic emotions and their implications for student success in STEM

Abstract Background Understanding student anxiety is an important factor for broadening the gender diversity of STEM majors due to its disproportionate and negative influence on women. To investigate how student anxiety is related to other academic emotions I conducted open-ended interviews with 19 university students and analyzed the data using emergent grounded theory. Emergent grounded theory uses inductive and deductive reasoning to develop a model of cognition and human behavior. Results Data analysis led to the development of a detailed theoretical model outlining connections among student anxiety, positive and negative academic emotions, self-regulated learning, and performance. In addition, the data highlight important emotional differences between men and women that have the potential to influence retention in STEM. Specifically, the model elaborates on the concept of a self-deprecating cycle driven by negative academic emotions and suggests that women may be more likely to become trapped in this cycle. Conclusion The model incorporates students’ emotions as a powerful influence on performance and can be used to inform strategies aimed at changing how university students experience and deal with emotions such as student anxiety

Developmental programming by xenoestrogens

Title from PDF of title page (University of Missouri--Columbia, viewed on May 31, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Susan NagelVita.Includes bibliographical references.Ph. D. University of Missouri-Columbia 2011."December 2011"[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Xenoestrogens (XE) are chemicals in the environment that mimic the body's natural steroidal estrogens. Developmental exposure to XE may interfere with normal hormonal signaling and result in altered disease susceptibility in adulthood. I used mouse models to examine the effects on three disease endpoints of developmental exposure to three relevant XE: bisphenol A, a ubiquitous chemical found in many food packaging and plastic products; ethinyl estradiol, the primary component of most oral contraceptive pills; and diethylstilbestrol, a former pharmaceutical that has been linked to increased cancer incidence in women exposed in utero. Endometriosis is an estrogen-dependent, benign gynecological disease. First, using a model of surgically-induced endometriosis, I demonstrated that the altered gene expression profile in mice closely mirrors what is observed in women with the disease. I then used this model to explore the effects of developmental XE exposure on endometriosis. Developmental XE exposure was found to alter the expression of immunomodulatory genes. Second, I examined the effects of developmental XE exposure on adult femoral shape and strength. I found that developmental XE exposure increased femoral length and decreased femoral strength, causing bones to fracture more easily. Third, I found that developmental XE exposure increased mammary gland density and tended to increase intraductal hyperplasia. Importantly these effects were seen within the range of current human exposure. Overall my research demonstrates that developmental programming by XE is linked to increased disease susceptibility in adulthood; exposure to low-environmentally relevant levels of XE may increase the risk of endometriosis, bone fractures, and breast cancer

COMMUNITY SUPPORTED AGRICULTURE (CSA): A HYPOTHESIS TEST OF MEMBERSHIP ACTIVITIES AND UTILITY

This study examines whether membership activities of Community Supported Agriculture (CSA) farms can yield utility directly. Results based on survey data from Vermont suggest that time spent in picking up produce from a CSA farm and time spent in cleaning and putting away produce at home do yield utility directly and the direct utility from picking up is greater than that from cleaning and putting away