Economic and environmental nitrate leaching consequences of 4R nitrogen management practices including use of inhibitors for corn production in Ontario.

Nitrate (NO) leaching has negative human and environmental health consequences that can be attributed to and mitigated by agricultural decision making. The purpose of this study is to examine the economic and environmental nitrogen (N) leaching reduction from 4R (Right Rate, Right Source, Right Time, Right Placement) agricultural management practices, including application methods, timing and rates, and the use of nitrification and urease inhibitors, for Ontario corn production. This study employed an integrated biophysical and economic GIS-based simulation model considering corn yields, prices, and production costs, and environmental losses, under historical weather scenarios, with NO leaching constraints.

Modifying fertilizer rate and application method reduces environmental nitrogen losses and increases corn yield in Ontario.

Nitrogen (N) use in corn production is an important driver of nitrous oxide (NO) emissions and 4R (Right source, Right rate, Right time and Right place) fertilizer practices have been proposed to mitigate emissions. However, combined 4R practices have not been assessed for their potential to reduce NO emissions at the provincial-scale while also considering trade-offs with other N losses such as leaching or ammonia (NH) volatilization. The objectives of this study were to develop, validate, and apply a Denitrification-Decomposition model framework at 270 distinct soil-climate regions in Ontario to simulate corn yield and NO emissions across eleven fertilizer management scenarios during 1986-2015.

Simulating nitrogen management impacts on maize production in the U.S. Midwest.

Nutrient loss reduction strategies have recently been developed in the U.S. Midwest to decrease the environmental footprint associated with nitrogen (N) fertilizer use.

A Vision for Incorporating Environmental Effects into Nitrogen Management Decision Support Tools for U.S. Maize Production.

Meeting crop nitrogen (N) demand while minimizing N losses to the environment has proven difficult despite significant field research and modeling efforts. To improve N management, several real-time N management tools have been developed with a primary focus on enhancing crop production. However, no coordinated effort exists to simultaneously address sustainability concerns related to N losses at field- and regional-scales.

Identification of dipole disorder in low temperature solution processed oxides: its utility and suppression for transparent high performance solution-processed hybrid electronics.

The ability to deposit high-quality inorganic semiconductors and dielectrics from solution at low process temperatures (∼200 °C) has become a very important research focus. During the course of our investigation, we identify the presence of an induced dipole present in solid state solution processed inorganic oxide insulator layers processed at reduced temperature (200-350 °C) from either molecular precursors, or well-dispersed metal oxide nanoparticles. Chemical composition analysis coupled with electrical measurements shows that the dielectric instability occurs due to proton migration the Grotthuss mechanism inducing a long lived dipole disorder.

Electronic Structure of Low-Temperature Solution-Processed Amorphous Metal Oxide Semiconductors for Thin-Film Transistor Applications.

The electronic structure of low temperature, solution-processed indium-zinc oxide thin-film transistors is complex and remains insufficiently understood. As commonly observed, high device performance with mobility >1 cm V s is achievable after annealing in air above typically 250 °C but performance decreases rapidly when annealing temperatures ≤200 °C are used. Here, the electronic structure of low temperature, solution-processed oxide thin films as a function of annealing temperature and environment using a combination of X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and photothermal deflection spectroscopy is investigated.

Global patterns and controls of soil organic carbon dynamics as simulated by multiple terrestrial biosphere models: Current status and future directions.

Soil is the largest organic carbon (C) pool of terrestrial ecosystems, and C loss from soil accounts for a large proportion of land-atmosphere C exchange. Therefore, a small change in soil organic C (SOC) can affect atmospheric carbon dioxide (CO) concentration and climate change. In the past decades, a wide variety of studies have been conducted to quantify global SOC stocks and soil C exchange with the atmosphere through site measurements, inventories, and empirical/process-based modeling.

Complex spatiotemporal responses of global terrestrial primary production to climate change and increasing atmospheric CO2 in the 21st century.

Quantitative information on the response of global terrestrial net primary production (NPP) to climate change and increasing atmospheric CO2 is essential for climate change adaptation and mitigation in the 21st century. Using a process-based ecosystem model (the Dynamic Land Ecosystem Model, DLEM), we quantified the magnitude and spatiotemporal variations of contemporary (2000s) global NPP, and projected its potential responses to climate and CO2 changes in the 21st century under the Special Report on Emission Scenarios (SRES) A2 and B1 of Intergovernmental Panel on Climate Change (IPCC). We estimated a global terrestrial NPP of 54.

High Performance, Low Temperature Solution-Processed Barium and Strontium Doped Oxide Thin Film Transistors.

Amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor (TFT) applications, with indium gallium zinc oxide, InGaZnO (IGZO), being one of the most widely studied and best performing systems. Here, we investigate alkaline earth (barium or strontium) doped InBa(Sr)ZnO as alternative, semiconducting channel layers and compare their performance of the electrical stress stability with IGZO. In films fabricated by solution-processing from metal alkoxide precursors and annealed to 450 °C we achieve high field-effect electron mobility up to 26 cm V s.

Do nitrogen fertilizers stimulate or inhibit methane emissions from rice fields?

In rice cultivation, there are controversial reports on net impacts of nitrogen (N) fertilizers on methane (CH ) emissions. Nitrogen fertilizers increase crop growth as well as alter CH producing (Methanogens) and consuming (Methanotrophs) microbes, and thereby produce complex effects on CH emissions. Objectives of this study were to determine net impact of N fertilizers on CH emissions and to identify their underlying mechanisms in the rice soils.

Arsenic contamination in soil-water-plant (rice, Oryza sativa L.) continuum in central and sub-mountainous Punjab, India.

In the present study, Arsenic (As) concentrations in underground water, soil, and plants (rice) and their inter-relationships in central and sub-mountainous Punjab, India were studied. Approximately, 32% of the tubewell water samples had As concentrations greater than the maximum permissible limit (10 μg As L(-1)) set by the World Health Organization (WHO) whereas in hand pump waters, As concentrations were within the safe range (i.e.

Low-temperature, high-performance solution-processed metal oxide thin-film transistors formed by a ‘sol–gel on chip’ process.

At present there is no ‘ideal’ thin-film transistor technology for demanding display applications, such as organic light-emitting diode displays, that allows combining the low-temperature, solution-processability offered by organic semiconductors with the high level of performance achievable with microcrystalline silicon1. N-type amorphous mixed metal oxide semiconductors, such as ternary oxides Mx1My2Oz, where M1 and M2 are metals such as In, Ga, Sn, or Zn, have recently gained momentum because of their high carrier mobility and stability2, 3 and good optical transparency, but they are mostly deposited by sputtering. So far no route is available for forming high-performance mixed oxide materials from solution at low process temperatures <250 °C.

A new facile route for the preparation of single-source precursors for bulk, thin-film, and nanocrystallite I-III-VI semiconductors.

We report a new simplified synthetic procedure for commercial manufacture of ternary single-source precursors (SSPs). This new synthetic process has been successfully implemented to fabricate known SSPs on bulk scale and the first liquid SSPs to the semiconductors CuInSe(2) and AgIn(x)S(y). Single crystal X-ray determination reveals the first unsolvated ternary AgInS SSP.

Regulation of rat olfactory glutathione S-transferase expression. Investigation of sex differences, induction, and ontogenesis.

The glutathione S-transferases (GSTs) of rat olfactory epithelium have been characterised with regard to sex differences, induction, and developmental regulation, and compared to those of the liver. Olfactory cytosolic GST activity with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate was similar in both male and female animals, and there were no differences in subunit profile. Administration of trans-stilbene oxide and beta-naphthoflavone had no effect on olfactory GST activity with CDNB, although phenobarbitone treatment resulted in a small, but significant, increase in activity (130% compared to controls).

Olfactory toxicity of methyl iodide in the rat.

The monohalomethanes (methyl iodide, methyl bromide and methyl chloride) are widely used industrial methylating agents with pronounced acute and chronic toxicity in both experimental animals and man. Recently inhalation exposure of rats to methyl bromide has been shown to result in severe olfactory toxicity. This study examined the effects on the rat nasal cavity of inhalation of methyl iodide (100 ppm for 0.

Immunohistochemical localisation of six glutathione S-transferases within the nasal cavity of the rat.

Many xenobiotics induce lesions within the nasal cavity of experimental animals which are site specific. This site selectivity may be due to regional deposition within the nasal cavity and/or the localisation of biotransformation enzymes. We have developed methodology which allows immunohistochemical localisation of xenobiotic biotransformation enzymes in transverse sections of the rat nasal cavity identical to those normally taken for pathological examination.

The characterization of glutathione S-transferases from rat olfactory epithelium.

The glutathione S-transferases (GSTs) of rat olfactory epithelium have been characterized with regard to substrate specificity and subunit composition and compared to those of the liver. The presence of cytosolic GST activity in rat olfactory epithelium was confirmed and, using 1-chloro-2,4-dinitrobenzene as substrate, was found to be approximately one-third that of the liver. Olfactory microsomal GST activity was greater than that of liver microsomes and could be activated by treatment with the sulphydryl agent N-ethylmaleimide.