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Emmitsburg, MD, United States

Mount St. Mary's University, also known as The Mount, is a private, liberal arts, Catholic university in the Catoctin Mountains near historic Emmitsburg, Maryland Wikipedia.


Simmons J.A.,Mount St. Marys University
Environmental Toxicology and Chemistry | Year: 2012

In many freshwater systems around the world, the concentrations of major ions (Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, CO32-, and SO42-) are exhibiting increasing trends, approaching the concentrations historically found mainly in estuaries. The objectives of the present study were to determine at what concentrations these salts are toxic to an aquatic plant and a green alga, to investigate two potential mechanisms of toxicity, and to determine the usefulness of conductivity as an indicator of salt toxicity. In a series of laboratory trials, Lemna minor and Pseudokirchneriella subcapitata were exposed to a range of concentrations of five different salts. Conductivity levels that caused 10 or 50% reductions in growth-related traits (EC10 and EC50, respectively) were determined, using conductivity of the test solutions as the independent variable. The EC10 values ranged from 0.44 to 2.67mS/cm for P. subcapitata and from 1.3 to >19mS/cm for L. minor. The EC50 values ranged from 1.7 to 5.8mS/cm for P. subcapitata and from 4.2 to >27mS/cm for L. minor. For both species the EC values varied dramatically among the salts. Pseudokirchneriella subcapitata was most sensitive to KCl and NaCl, whereas L. minor was most sensitive to Na2SO4. The mechanism of toxicity does not appear to be related to production of reactive oxygen species, nor to reduction in chlorophyll concentrations. Because toxicity was strongly influenced by salt composition, regulation and management of specific ions may be preferable to conductivity. © 2012 SETAC. Source


Schwenkler J.,Mount St. Marys University
i-Perception | Year: 2012

How do we recognize identities between seen shapes and felt ones? Is this due to associative learning, or intrinsic connections these sensory modalities? We can address this question by testing the capacities of newly sighted subjects to match seen and felt shapes, but only if the subjects can see the objects well enough to form adequate visual representations of their shapes. In light of this, a recent study by R. Held and colleagues fails to demonstrate that their newly sighted subjects' inability to match seen and felt shape was due to a lack of intermodal connections rather than a purely visual deficit, as the subjects may not have been able visually to represent 3D shape in the perspective-invariant manner required for intermodal matching. However, the study could be modified in any of several ways to help avoid this problem. © 2012 J Schwenkler. Source


Hung-Low F.,Texas Tech University | Bradley C.A.,Texas Tech University | Bradley C.A.,Mount St. Marys University
Inorganic Chemistry | Year: 2013

Alkali metal reduction of (η5-C9H 5-1,3-(SiMe3)2)2Co (1) in tetrahydrofuran (THF) permits isolation of the unusual and reactive 20 electron Co(I) anion [Na(THF)6][(η5-C9H 5-1,3-(SiMe3)2)2Co] (2). Crystallographic characterization of both 1 and 2 provide support for the one electron reduction from Co(II) to Co(I). Reactivity studies of 2 are further consistent with a Co(I) equivalent, based on both one electron chemical oxidation to reform 1 and reaction with a variety of σ and π donors. Upon addition of pyridines or vinyltrimethylsilane to 2, known dimer [(C 9H5-1,3-(SiMe3)2)2Co 2] (3) is formed, likely through 16 electron (η5- C9H5-1,3-(SiMe3)2)Co(L) intermediates. Ethylene addition to 2 establishes an equilibrium between (η5-C9H5-1,3-(SiMe3) 2)Co(η2-H2C-CH2)2 (8) and 2, suggestive of reversible ligand ejection from 2. Crossover experiments between a related metal indenide salt and 2 confirm ligand extrusion from the anion, even in the absence of strong supporting donors. Reaction of 2 with PMe3 results in formation of 3, (η5-C 9H5-1,3-(SiMe3)2)Co(PMe 3)2 (13), and a paramagnetic species, with the product ratios being highly dependent on the conditions of synthesis. Collectively, 2 demonstrates an alternative entry point into the chemistry of 14 electron Co(I) equivalents when compared to typical ligand loss from neutral 18 electron cyclopentadienyl cobalt bis(ligand) complexes, perhaps permitting generation of low electron count species more effective for small molecule activation. © 2013 American Chemical Society. Source


Turner M.,Yale University | Turner M.,Mount St. Marys University | Turner M.,U.S. Army | Jiao A.,Yale University | Slack F.J.,Yale University
Cell Cycle | Year: 2014

The conserved lin-4 microRNA (miRNA) regulates the proper timing of stem cell fate decisions in C. elegans by regulating stemness genes such as lin-14 and lin-28.1-3 While lin-4 is upregulated toward the end of the first larval stage and functions as an essential developmental timing "switch", little is known about how lin-4 expression is regulated.4 Here we show that in C. elegans hypodermal seam cells, transcription of lin-4 is positively regulated by lin-4 itself. In these cells, lin-4 activates its own transcription through a conserved lin-4-complementary element (LCE) in its promoter. We further show that lin-4 is required to recruit RNA polymerase II to its own promoter, and that lin-4 overexpression is sufficient for autoactivation. Finally, we show that a protein complex specifically binds the LCE in vitro, and that mutations that abolish this binding also reduce the in vivo expression of a plin-4: GFP reporter. Thus, we describe the first in vivo evidence of RNA activation (RNAa) by an endogenous miRNA, and provide new insights into an elegant autoregulatory mechanism that ensures the proper timing of stem cell fate decisions in development. © 2014 Landes Bioscience. Source


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: CHEMICAL INSTRUMENTATION | Award Amount: 183.25K | Year: 2013

With this award from the Major Research Instrumentation Program that is co-funded by the Chemistry Research Instrumentation and Facilities (CRIF) Program, Professor Christopher Bradley from Mount St Marys University and colleagues Daesung Chong (Ball State University), Tomothy Brunker (Towson University), Peter Craig (McDaniel College) and Timothy Funk (Gettysburg College) will acquire a single crystal X-ray diffractometer for use by a consortium of primarily undergraduate institutions that include Mount St Marys University, Ball State University, Towson University, McDaniel College, Gettysburg College and Loyola University Maryland. The award is aimed at enhancing research and education at all levels, especially in areas such as (a) arene effects on cobalt catalysts for activated alkane dehydrogenation; (b) redox-induced linkage isomerism in chiral ruthenium sulfoxide complexes; (c) investigation of the stabilization of boron-containing cations by azametallocenes; (d) studies of model enzyme complexes; (e) coordination chemistry studies; (f) development of transition metal catalysts for organic transformations; (g) synthesis, reactivity, and crystallographic characterization of transition metal carbonyl complexes containing oxygen-donating ligands; and (h) catalysts for proton reduction.

An X-ray diffractometer allows accurate and precise measurements of the full three-dimensional structure of a molecule, including bond distances and angles, and provides accurate information about the spatial arrangement of a molecule relative to neighboring molecules. The studies described here will impact a number of areas, including organic and inorganic chemistry, materials chemistry and biochemistry. This instrument will be an integral part of teaching as well as research and research training not only at Mount St Marys University but also at the neighboring institutions included in the consortium.

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