Proximate controls on semiarid soil greenhouse gas fluxes across 3 million years of soil development

Soils are important sources and sinks of three greenhouse gases (GHGs): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, it is unknown whether semiarid landscapes are important contributors to global fluxes of these gases, partly because our mechanistic understanding of soil GHG fluxes is largely derived from more humid ecosystems. We designed this study with the objective of identifying the important soil physical and biogeochemical controls on soil GHG fluxes in semiarid soils by observing seasonal changes in soil GHG fluxes across a three million year substrate age gradient in northern Arizona. We also manipulated soil nitrogen (N) and phosphorus availability with 7 years of fertilization and used regression tree analysis to identify drivers of unfertilized and fertilized soil GHG fluxes. Similar to humid ecosystems, soil N2O flux was correlated with changes in N and water availability and soil CO2 efflux was correlated with changes in water availability and temperature. Soil CH4 uptake was greatest in relatively colder and wetter soils. While fertilization had few direct effects on soil CH4 flux, soil nitrate was an important predictor of soil CH4 uptake in unfertilized soils and soil ammonium was an important predictor of soil CH4 uptake in fertilized soil. Like in humid ecosystems, N gas loss via nitrification or denitrification appears to increase with increases in N and water availability during ecosystem development. Our results suggest that, with some exceptions, the drivers of soil GHG fluxes in semiarid ecosystems are often similar to those observed in more humid ecosystems

A-Void-Able Consequences: Void Sales & Subsequent Purchasers Under Arkansas’s Statutory Foreclosure Act

This Comment explores Arkansas’s Statutory Foreclosure Act and addresses the question of whether there can be a “subsequent purchaser for value” when a foreclosure sale is void from the outset. After a review of the Act itself, distinction between void and voidable foreclosures of property, findings of other state courts, and proper application of the Act, the author urges the Arkansas Supreme Court to make a formal declaration finding that purchasers of property foreclosed upon in a void sale are not “subsequent purchasers for value” under the meaning of the statute

The Rearview Mirror and Windshield: Utilizing the Intersection of Nostalgia and Neophila to Target Today\u27s Consumers

In a technologically-advanced, rapidly-changing business world, successful marketing practice is becoming more and more elusive to the competing corporations. Two popular tactics—nostalgia and neophilia—have been shown to both dazzle and destroy, depending upon their use. These concepts have been utilized by a variety of brands—some of the world’s largest beverage companies, the most popular application of 2016 and air fresheners, to name a few—and have resulted in heavy profits and losses for the companies. Nostalgia and neophilia in marketing must first be analyzed as individual concepts, each with their own merits and disadvantages, and then viewed as an intersection where one cannot be successful without a touch of the other. As this is analyzed, patterns begin to emerge as to that brand/product which is successful in the pursuit of these marketing ploys and that which essentially falls flat. These patterns can create a “formula,” if you will, for ideal marketing where nostalgia and neophilia meet. To best understand these concepts individually and this combination, it is perhaps best to view them through the lens of an age demographic that is currently mounting in size and purchasing power. This age demographic is Generation Y (popularly known as the “millennials”) who have their own particular affinity for nostalgia, neophilia and everything in between

A positive relationship between the abundance of ammonia oxidizing archaea and natural abundance δ15N of ecosystems

We present a significant relationship between the natural abundance isotopic composition of ecosystem pools and the abundance of a microbial gene. Natural abundance 15N of soils and soil DNA were analysed and compared with archaeal ammonia oxidizer abundance along an elevation gradient in northern Arizona and along a substrate age gradient in Hawai'i. There was a significant positive correlation between the abundance of archaeal amoA genes and natural abundance δ15N of total soil or DNA suggesting that ammonia oxidizing archaea play an important role in ecosystem N release. © 2013 Elsevier Ltd

Texas v. Cobb: A Narrow Road Ahead for the Sixth Amendment Right to Counsel

Raymond Cobb stabbed sixteen-month-old Kori Rae Owings\u27s mother in the stomach while he was attempting to steal the stereo from their home. He then took the mother\u27s body into the woods behind the house

Stable Carbon Isotope Fractionation in Chlorinated Ethene Degradation by Bacteria Expressing Three Toluene Oxygenases

One difficulty in using bioremediation at a contaminated site is demonstrating that biodegradation is actually occurring in situ. The stable isotope composition of contaminants may help with this, since they can serve as an indicator of biological activity. To use this approach it is necessary to establish how a particular biodegradation pathway affects the isotopic composition of a contaminant. This study examined bacterial strains expressing three aerobic enzymes for their effect on the 13C/12C ratio when degrading both trichloroethene (TCE) and cis-1,2-dichloroethene (c-DCE): toluene 3-monoxygenase, toluene 4-monooxygenase, and toluene 2,3-dioxygenase. We found no significant differences in fractionation among the three enzymes for either compound. Aerobic degradation of c-DCE occurred with low fractionation producing δ13C enrichment factors of −0.9 ± 0.5 to −1.2 ± 0.5, in contrast to reported anaerobic degradation δ13C enrichment factors of −14.1 to −20.4‰. Aerobic degradation of TCE resulted in δ13C enrichment factors of −11.6 ± 4.1 to −14.7 ± 3.0‰ which overlap reported δ13C enrichment factors for anaerobic TCE degradation of −2.5 to −13.8‰. The data from this study suggest that stable isotopes could serve as a diagnostic for detecting aerobic biodegradation of TCE by toluene oxygenases at contaminated sites