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

Tree species and moisture effects on soil sources of N2O: Quantifying contributions from nitrification and denitrification with O-18 isotopes

Nitrous oxide (N2O) is an important greenhouse gas and participates in the destruction of stratospheric ozone. Soil bacteria produce N2O through denitrification and nitrification, but these processes differ radically in substrate requirements and responses to the environment. Understanding the controls over N2O efflux from soils, and how N2O emissions may change with climate warming and altered precipitation, require quantifying the relative contributions from these groups of soil bacteria to the total N2O flux. Here we used ammonium nitrate (NH4NO3, including substrates for both processes) in which the nitrate has been enriched in the stable isotope of oxygen, O-18, to partition microbial sources of N2O, arguing that a molecule of N2O carrying the O-18 labeled will have been produced by denitrification. We compared the influences of six common tree species on the relative contributions of nitrification and denitrification to N2O flux from soils, using soils from the Siberian afforestation experiment. We also altered soil water content, to test whether denitrification becomes a dominant source of N2O when soil water content increases. Tree species altered the proportion of nitrifier and denitrifier-derived N2O. Wetter soils produced more N2O from denitrification, though the magnitude of this effect varied among tree species. This indicates that the roles of denitrification and nitrification vary with tree species, and, that tree species influence soil responses to increased water content