Farm to School: A Market Analysis

This paper explores the potential for the National Farm to School Program to effectively engage with Georgia’s public schools in order to reduce local food insecurity and improve the quality of nutrition provided to students. A survey was conducted with the specific goals of assessing: first, the current and future impact Farm to School has and will potentially have on the Georgia economy through schools purchase of local foods; second, the potential market for farmers; third, school administrators willingness to buy local food by Georgia; forth, the level of infrastructure available within schools to prepare fresh, whole foods; and fifth, the perceived opportunities and challenges to buying and preparing local food. University of Georgia collaborated with the Georgia Department of Education and Georgia Organics to develop a survey that met the objectives as defined above. There were twenty-five questions total and most answers were formatted in a multiple-choice selection with an option to write any additional comments. The survey was distributed by the Department of Education to 158 public schools in Georgia, and collected, a total of 93 responses. From the data, it was concluded that the willingness to participate exists, as well as the tools necessary for participation. What appears to be missing is the infrastructure that would allow schools to purchase food easily and frequently. Most schools noted that they would be willing to interact with an online platform that would put them in contact with local growers and sellers.Farm to School, Georgia, Local foods, public schools, survey data for local buying, food security, Agricultural and Food Policy, Community/Rural/Urban Development, Food Consumption/Nutrition/Food Safety, Food Security and Poverty,

IPO Underpricing Firm Quality, and Subsequent Reissuance Activity

A signaling argument has recently been developed whereby IPO underpricing is a signal of future firm value. Only higher quality firms can be expected to recover the cost of this signal through subsequent offerings of seasoned equities. This study uses three proxies for firm quality and finds evidence of a positive relationship between these measures of firm quality and reissuance activity. Greater IPO underpricing is also found to be associated with greater levels of future equity selling and higher levels of earnings per share

Progress report on friction loss of slurries in straight tubes

This progress report summarizes the work to date on the experimental evaluation of the head loss of slurries flowing in horizontal and vertical tubes. The slurries used in the investigation were spherical glass beads and ion exchange resin particles suspended in water. The tube size used was approximately 0. 3-in. inside diameter. Concentrations from zero to approximately 50 percent by weight were used

Quantum Degenerate Exciton-Polaritons in Thermal Equilibrium

We study the momentum distribution and relaxation dynamics of semiconductor microcavity polaritons by angle-resolved and time-resolved spectroscopy. Above a critical pump level, the thermalization time of polaritons at positive detunings becomes shorter than their lifetime, and the polaritons form a quantum degenerate Bose-Einstein distribution in thermal equilibrium with the lattice.Comment: Updated with the published versio

Rapid deposition of oxidized biogenic compounds to a temperate forest

We report fluxes and dry deposition velocities for 16 atmospheric compounds above a southeastern United States forest, including: hydrogen peroxide (H_2O_2), nitric acid (HNO_3), hydrogen cyanide (HCN), hydroxymethyl hydroperoxide, peroxyacetic acid, organic hydroxy nitrates, and other multifunctional species derived from the oxidation of isoprene and monoterpenes. The data suggest that dry deposition is the dominant daytime sink for small, saturated oxygenates. Greater than 6 wt %C emitted as isoprene by the forest was returned by dry deposition of its oxidized products. Peroxides account for a large fraction of the oxidant flux, possibly eclipsing ozone in more pristine regions. The measured organic nitrates comprise a sizable portion (15%) of the oxidized nitrogen input into the canopy, with HNO_3 making up the balance. We observe that water-soluble compounds (e.g., strong acids and hydroperoxides) deposit with low surface resistance whereas compounds with moderate solubility (e.g., organic nitrates and hydroxycarbonyls) or poor solubility (e.g., HCN) exhibited reduced uptake at the surface of plants. To first order, the relative deposition velocities of water-soluble compounds are constrained by their molecular diffusivity. From resistance modeling, we infer a substantial emission flux of formic acid at the canopy level (∼1 nmol m^(−2)⋅s^(−1)). GEOS−Chem, a widely used atmospheric chemical transport model, currently underestimates dry deposition for most molecules studied in this work. Reconciling GEOS−Chem deposition velocities with observations resulted in up to a 45% decrease in the simulated surface concentration of trace gases

High-Sensitivity Serum Calcitonin Assays Applied to Screening for Thyroid C-Cell Disease in Multiple Endocrine Neoplasia Type 2A

Two serum calcitonin assays with sensitivities ≤ 10 pg/mL were compared to our standard radioimmunoassay (sensitivity 100 pg/mL) in multiple endocrine neoplasia type 2A (MEN 2A) screening. Values from the Nichols displacement radioimmunoassay averaged 38% higher than values from the CIS immunoradiometric assay; values from both were highly correlated, r = 0.845. In three individuals, both of the newer assays revealed abnormalities in pentagastrin tests three to four years before abnormalities were detected by the standard assay. Pentagastrin tests after total thyroidectomy were assayed by the newer methods in patients with medullary thyroid carcinoma (MTC) diagnosed at initial testing (group I); in patients with early MTC diagnosed by prospective screening (group ll); and in patients with pure C-cell hyperplasia detected by prospective screening (group III). At least 64% of group I, at least 25% of group II, but none of group III had detectable postoperative C-cell function. Conclusions: 1) The previous estimate of 12 years as median age of onset of C-cell disease in MEN 2A is probably three to four years too old. 2) Patients diagnosed with early MTC by screening had not necessarily skipped a preneoplastic phase of C-cell hyperplasia. At least some early disease was not detected by the standard assay. Higher sensitivity assays should improve screening for C-cell disease by earlier disease detection. 3) Biochemical cure by thyroidectomy after the development of MTC is not as frequent as previously thought, but the apparent cure rate of pure C-cell hyperplasia remains 100%

Why do models overestimate surface ozone in the Southeast United States

Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx  ≡  NO + NO2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC4RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25°  ×  0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NOx from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC4RS observations of NOx and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO2 columns. Our results indicate that NEI NOx emissions from mobile and industrial sources must be reduced by 30–60 %, dependent on the assumption of the contribution by soil NOx emissions. Upper-tropospheric NO2 from lightning makes a large contribution to satellite observations of tropospheric NO2 that must be accounted for when using these data to estimate surface NOx emissions. We find that only half of isoprene oxidation proceeds by the high-NOx pathway to produce ozone; this fraction is only moderately sensitive to changes in NOx emissions because isoprene and NOx emissions are spatially segregated. GEOS-Chem with reduced NOx emissions provides an unbiased simulation of ozone observations from the aircraft and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NOx oxidation products. However, the model is still biased high by 6 ± 14 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone decrease from 1.5 km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer

Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States

Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events

Observational Constraints on Glyoxal Production from Isoprene Oxidation and Its Contribution to Organic Aerosol over the Southeast United States

We use a 0-D photochemical box model and a 3-D global chemistry-climate model, combined with observations from the NOAA Southeast Nexus (SENEX) aircraft campaign, to understand the sources and sinks of glyoxal over the Southeast United States. Box model simulations suggest a large difference in glyoxal production among three isoprene oxidation mechanisms (AM3ST, AM3B, and Master Chemical Mechanism (MCM) v3.3.1). These mechanisms are then implemented into a 3-D global chemistry-climate model. Comparison with field observations shows that the average vertical profile of glyoxal is best reproduced by AM3ST with an effective reactive uptake coefficient gamma(sub glyx) of 2 x 10(exp -3) and AM3B without heterogeneous loss of glyoxal. The two mechanisms lead to 0-0.8micrograms m(exp -3) secondary organic aerosol (SOA) from glyoxal in the boundary layer of the Southeast U.S. in summer. We consider this to be the lower limit for the contribution of glyoxal to SOA, as other sources of glyoxal other than isoprene are not included in our model. In addition, we find that AM3B shows better agreement on both formaldehyde and the correlation between glyoxal and formaldehyde (RGF[GLYX]/[HCHO]), resulting from the suppression of delta-isoprene peroxy radicals (delta-ISOPO2). We also find that MCM v3.3.1 may underestimate glyoxal production from isoprene oxidation, in part due to an underestimated yield from the reaction of isoprene epoxydiol (IEPOX) peroxy radicals with HO2. Our work highlights that the gas-phase production of glyoxal represents a large uncertainty in quantifying its contribution to SOA