Arkansas Corn and Grain Sorghum Performance Tests 2003

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas Division of Agriculture. The tests provide information to companies marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers

Arkansas Soybean Performance Tests 2002

Soybean cultivar performance tests are conducted each year in Arkansas by the University of Arkansas Division of Agriculture. The tests provide information to companies developing cultivars and/or marketing seed within the State, and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for soybean producers. The 2002 soybean cultivar performance tests were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Cotton Branch Station (CBS) near Marianna, the Rice Research and Extension Center (RREC) near Stuttgart, the Southeast Research and Extension Center - Rohwer Division (SEREC-RD) near Rohwer, the Burton Brothers Farm (BBF) in LaFayette County, and the Vegetable Substation (VSS) near Kibler. A test location map can be found inside the back cover

Arkansas Soybean Performance Tests 2003

Soybean cultivar performance tests are conducted each year in Arkansas by the University of Arkansas Division of Agriculture. The tests provide information to companies developing cultivars and/or marketing seed within the State and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for soybean producers

Arkansas Corn and Grain Sorghum Performance Tests 2002

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2002 corn performance tests contained 59 entries and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Cotton Branch Station (CBS) near Marianna, the Bell Farming Company (BFC) near Des Arc, the Southeast Research and Extension Center - Rohwer Division (SEREC-RD) near Rohwer, and the John Williams Farm (JWF) in Lafayette County. The 2002 grain sorghum performance tests contained 34 entries and were conducted at the NEREC at Keiser, the CBS near Marianna, the Pine Tree Experiment Station (PTS) near Pine Tree, the SEREC-RD near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. Test location maps for grain sorghum and corn can be found inside the back cover

Arkansas Corn and Grain Sorghum Performance Tests 2002

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers

Regulatory and metabolic rewiring during laboratory evolution of ethanol tolerance in E. coli

We have designed an experimental/computational framework for studying complex phenotypes in bacteria.Our framework relies on whole-genome fitness profiling coupled with a module-level analysis to discover pathways that directly affect fitness.As a proof-of-principle, we studied ethanol tolerance in Escherichia coli and we identified key pathways that contribute to this phenotype.We then validated our findings through genetic manipulations, gene-expression profiling, metabolite-level measurements, and stable-isotope labeling

Stability assessment of organic sulfur and organosulfate compounds in filter samples for quantification by Fourier- transform infrared spectroscopy

Organic sulfur and sulfate compounds, which are tracers for sources and atmospheric processes, are not currently measured in national monitoring networks such as the Interagency Monitoring of Protected Visual Environments (IMPROVE). The goal of this paper is to begin to assess the stability of organic sulfur and sulfate-containing compounds on polytetrafluoroethylene (PTFE) filters and the suitability of Fourier-transform infrared (FT-IR) spectroscopy to measure these compounds. Stability assessment is needed because PTFE samples collected by IMPROVE are typically stored 6–9 months prior to analysis. For this study, two organosulfur compounds, methanesulfonic acid (MSA) and hydroxymethanesulfonate ion (HMS), and two organosulfate compounds, methyl sulfate (MS) and 2-methyltetrol sulfate (2-MTS), are collected individually on PTFE filters. Gravimetric mass measurements are used to assess mass stability over time. FT-IR spectra are evaluated to assess the capability of measuring the compound from PTFE filters by assessing the compound stability or chemical changes over time. Ion chromatography (IC) and inductively coupled plasma optical emission spectroscopy (ICP-OES) are used as additional tools to assess stability or chemical changes over time. MS has the highest potential to be measured by FT-IR in IMPROVE samples. For MS, a simple organosulfate, the mass changes are within measurement uncertainty and FT-IR spectra indicate no compositional change over a 4-month period, suggesting that MS can be measured using FT-IR. IC and ICP-OES support the conclusion that MS is stable on the filter. However, for 2-MTS, the other organosulfate measured in this study, spectral changes after a month on the filter suggest that it decomposes into other organosulfates or an inorganic sulfate. MSA in IMPROVE samples can be measured, but only as a lower bound, due to volatility off the filter as indicated by FT-IR and gravimetry. FT-IR and IC both show that MSA does not chemically change over the course of the study. Measurements by all methods indicate that HMS is unstable on the PTFE filter, and IC and FT-IR indicate that it likely converts to inorganic sulfate. Future work includes the evaluation of these compounds in an ambient aerosol sample matrix to determine any differences in stability, identifying interference that could limit quantification, and developing calibrations to measure the compounds or functional groups in ambient samples.</p