Advances in samarium-neodymium geochronology: applications to early earth garnet, hydrothermal carbonate, and high temperature metamorphic systems

This study utilizes recent advances in the analysis of neodymium (Nd) and samarium (Sm) by thermal ionization mass spectrometry (TIMS) to constrain timescales of heating and fluid flow within the lithosphere. Garnet grows during metamorphism and can be linked to its pressure and temperature of growth, while carbonate mineralization ages can be linked to hydrothermal fluid flow. The ability to date these common minerals makes it possible to unravel the timing and duration of tectonometamorphic processes. Garnet from the Eoarchean Nuvvuagittuq Supracrustal Belt (NSB) in Québec, Canada yields an age of 2574.66 ± 0.72 Ma. This is the most precise Neoarchean age reported for this terrane and was achieved through a modified partial dissolution procedure designed to remove the effects of much older (up to 3.8 Ga) inherited mineral growth. An accurate age for the most recent metamorphic garnet in the NSB is critical, as the (controversial) Hadean Nd model age calculations for this terrane depend on the time at which the 147Sm/144Nd systematics were last altered. Carbonate mineralization ages are explored for a diverse group of thirty samples using a novel sequential acid extraction procedure. Through this procedure it is possible to constrain carbonate mineralization in a variety of geologic settings (metamorphic fluid flow, hydrothermal and ore-forming systems) to ± 20 Myr. Zoned and bulk garnet geochronology at ten sites within a unusually localized area (~5 km2) of high temperature granulite-facies metamorphism in Bristol, New Hampshire reveals multiple brief (<1 Myr) periods of garnet growth focused between 393 and 386 Ma, at peak temperatures of 730-850°C. Comparison with garnet growth ages and temperatures , in central Massachusetts (364 Ma at 950°C) and Connecticut (341 Ma at 1000°C) reveal a regional trend of pulsed high temperature garnet growth spanning ~60 Myr from north to south, the same time span bracketed by associated igneous rocks dated via zircon geochronology. Ultrahigh metamorphic temperatures were achieved during the Acadian Orogeny in New England in localized, short pulses, likely related to igneous heating and/or associated fluid flow above and beyond the regional heating due to tectonic overthickening

Amity or annihilation, how teachers can promote world unity through intercultural education.

Thesis (M.A.)--Boston Universit

Quantifying the Dynamics of Bacterial Secondary Metabolites by Spectral Multiphoton Microscopy

Phenazines, a group of fluorescent small molecules produced by the bacterium Pseudomonas aeruginosa, play a role in maintaining cellular redox homeostasis. Phenazines have been challenging to study in vivo due to their redox activity, presence both intra- and extracellularly, and their diverse chemical properties. Here, we describe a noninvasive in vivo optical technique to monitor phenazine concentrations within bacterial cells using time-lapsed spectral multiphoton fluorescence microscopy. This technique enables simultaneous monitoring of multiple weakly fluorescent molecules (phenazines, siderophores, NAD(P)H) expressed by bacteria in culture. This work provides the first in vivo measurements of reduced phenazine concentration as well as the first description of the temporal dynamics of the phenazine-NAD(P)H redox system in Pseudomonas aeruginosa, illuminating an unanticipated role for 1-hydroxyphenazine. Similar approaches could be used to study the abundance and redox dynamics of a wide range of small molecules within bacteria, both as single cells and in communities

Systematic assessment of HER2/neu in gynecologic neoplasms, an institutional experience.

BackgroundHER2/neu overexpression and/or amplification has been widely studied in a number of solid tumors, primarily in the breast. In gynecologic neoplasms, determination of HER2/neu status has not been well studied as a predictive biomarker in anti-HER2/neu treatment.MethodsWe systematically evaluated the HER2/neu reactions by immunohistochemistry and fluorescent in situ hybridization in malignant gynecologic neoplasms as experienced in our institution.ResultsThe HER2/neu overexpression or amplification occurred in 8 % of the cancers of the gynecological organs in our series. Majority of the HER2/neu overexpression and/or amplification occurred in clear cell (27 %) and serous (11 %) carcinomas. HER2/neu positivity was also seen in undifferentiated as well as in mixed clear cell and serous carcinomas. Discordant IHC and FISH results (positive by FISH but not IHC) was seen in 2 cases. Majority of the HER2/neu overexpression and/or amplification occurs in the endometrium rather than the ovary. Heterogeneity of the HER2/neu by IHC staining was in &lt; 2 % of the tumors in our series.ConclusionsWe recommend the HER2/neu studies on Müllerian carcinomas of clear cell, serous, and undifferentiated types, particularly when they arise in the endometrium. Since there are some discordant IHC/FISH results, we also propose performing the HER2/neu testing by FISH when the IHC score is less than 3 + 

Speak as I say: an examination of legal standards applied to compelled speech in public high schools

First Amendment protections against the government compulsion of student speech in public high schools have been addressed by the U.S. Supreme Court on two occasions and by lower courts in seventeen additional cases. This thesis examines those nineteen cases to determine what level of First Amendment protection courts previously have recognized to protect against different types of compelled student speech. From this analysis of the cases, four categories of compelled student speech were identified - compelled recitations, compelled speech for mandatory education efforts, compelled speech as a form of punishment, and compelled speech that is both part of mandatory education efforts and a form of punishment. Utilizing these categories, a framework for courts to use in the future is proposed; this framework ensures that courts recognize the proper level of First Amendment protection against compelled student speech while also safeguarding the schools' ability to carry out their educational mission

Global Use of the Practice Environment Scale of the Nursing Work Index

Although the Practice Environment Scale of the Nursing Work Index has been endorsed as a gauge of the quality of the nursing practice environment by several organizations in the United States promoting healthcare quality, there is no literature describing its use in different practice settings and countries

The Complete Genome Sequence of Proteus mirabilis Strain BB2000 Reveals Differences from the P. mirabilis Reference Strain

We announce the complete genome sequence for Proteus mirabilis strain BB2000, a model system for self recognition. This opportunistic pathogen contains a single, circular chromosome (3,846,754 bp). Comparisons between this genome and that of strain HI4320 reveal genetic variations corresponding to previously unknown physiological and self-recognition differences.Molecular and Cellular Biolog

CYFC Monthly, January 2015

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu