How distorting are direct payments?

Agricultural and Food Policy,

Preparation, regioselective chemistry, and electronic properties of perfluoroalkylfullerenes

2013 Fall.Includes bibliographical references.A systematic study of how various reaction parameters affect the product distribution of gas-solid reactions was carried out in a new reactor of local design. These reactions involve the trifluoromethylation of C60, C70, and the endohedral metallofullerenes Sc3N@C80 and Y3N@C80; and in particular, the reactions were optimized to favor C60(CF3)2 and C60(CF3)4. A new solution phase homogeneous perfluoroalkylation method was used to prepare a series of 1,7-C60(RF)2 compounds with different RF chain lengths and branching patterns. A range of analytical methods including 19F NMR and UV-vis spectroscopy, APCI mass spectrometry, and X-ray crystallography were used to structurally characterize the compounds. Cyclic voltammetry, DFT E(LUMO) calculations, and gas phase electron affinity (EA) measurements were used to determine the substituent effect of the RF groups. The results conclusively showed that the solution phase E1/2, calculated E(LUMO), and EA values-- that are typically assumed to be correlated for a series of electron acceptors-- are not always correlated. Several highly efficient and selective methods were developed for the further functionalization of selected trifluoromethyl fullerenes (TMFs). These new functionalized TMFs were structurally characterized using the aforementioned analytical techniques and the X-ray crystal structures of five new derivatized TMFs were determined. Analysis of the how these newly derivatized TMFs pack in a crystalline solid revealed fullerene density values that were in general twice that of reported fullerenes that pack in the same motifs. These derivatized TMFs also exhibited extended networks of short C···C distances between fullerene cages of adjacent molecules that has been correlated to increased free charge carrier motilities in organic photovoltaic device active layers. The solution phase E1/2 values of the most commonly used fullerene derivatives in OPV devices were measured under carefully controlled conditions and revealed that poor reporting of electrochemical conditions, mistakes interpreting electrochemical data, and fullerene impurities have combined to cause significant confusion about the reported electrochemical values in the literature. A preliminary study of 32 OPV devices fabricated with active layers containing perfluoroalkylfullerenes (PFAFs) indicated that (i) PFAFs can function as suitable electron acceptors in OPVs, and (ii) that a more detailed study examining the complex electronic interplay between the fullerene electron acceptor and polymer donor is warranted

Growth rate and resource imbalance interactively control biomass stoichiometry and elemental quotas of aquatic bacteria

The effects of resource stoichiometry and growth rate on the elemental composition of biomass have been examined in a wide variety of organisms, but the interaction among these effects is often overlooked. To determine how growth rate and resource imbalance affect bacterial carbon (C): nitrogen (N): phosphorus (P) stoichiometry and elemental content, we cultured two strains of aquatic heterotrophic bacteria in chemostats at a range of dilution rates and P supply levels (C:P of 100:1 to 10,000:1). When growing below 50% of their maximum growth rate, P availability and dilution rate had strong interactive effects on biomass C:N:P, elemental quotas, cell size, respiration rate, and growth efficiency. In contrast, at faster growth rates, biomass stoichiometry was strongly homeostatic in both strains (C:N:P of 70:13:1 and 73:14:1) and elemental quotas of C, N, and P were tightly coupled (but not constant). Respiration and cell size increased with both growth rate and P limitation, and P limitation induced C accumulation and excess respiration. These results show that bacterial biomass stoichiometry is relatively constrained when all resources are abundant and growth rates are high, but at low growth rates resource imbalance is relatively more important than growth rate in controlling bacterial biomass composition.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136292/1/ecy1705_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136292/2/ecy1705.pd

Distributional Impact of U.S. Farm Commodity Programs: Accounting for Alternative Farm Household Typologies

Agricultural households adjust to policy changes through market mechanisms by altering: their production mix, labor input, and on- and off-farm investments. Because of the significant heterogeneity among farms in the US agricultural sector, various types of farm households respond to the same policy change in significantly different ways. The parameters used to classify farm households into different typologies may also play a significant role in the interpretation of observed effects of policy changes. This paper, using a highly disaggregated U.S. Computable General Equilibrium (CGE) model, analyzes the distributional impacts of policy changes involving price-contingent government payments on alternative U.S. farm household typologies. We find that farm households do vary their responses to an elimination of price-contingent support based on location, production specialty, and farm categorization.Agricultural and Food Policy,

Decoupled Programs, Payment Incidence, and Factor Markets: Evidence from Market Experiments

We use laboratory market experiments to assess the impact of asymmetric knowledge of a per-unit subsidy and the effect of a decoupled annual income subsidy on factor market outcomes. Results indicate that when the subsidy is tied to the factor as a per-unit subsidy, regardless of full or asymmetric knowledge for market participants, subsidized factor buyers distribute nearly 22 percent of the subsidy to factor sellers. When the subsidy is fully decoupled from the factor, as is the case with the annual payment, payment incidence is mitigated and prices are not statistically different from the no-policy treatment.laboratory market experiments, agricultural subsidies, subsidy incidence, land market, ex ante policy analysis, Agricultural and Food Policy, Institutional and Behavioral Economics, Q18, D03, C92,

Results of long-term, seasonal sampling for Penaeus postlarvae at Breach Inlet, South Carolina

Recruitment of postlarvae of commercially important penaeid shrimp has been studied in several areas in the southeastern United States, e.g. on the Atlantic coast and the Gulf of Mexico. Findings from these studies indicate that postlarvae are generally concentrated near oceanic inlets, different species are abundant at different times of the year, ingress through inlets into estuarine nursery areas is often influenced by factors such as tide and time of day, and correlations between number of postlarvae and subsequent commercial landings is often poor. In South Carolina most published studies have examined postlarval recruitment over a one- to two-year period. Long-term sampling was conducted by Lunz at several coastal sites in South Carolina in an effort to predict subsequent commercial harvest. As an extension of this work, long-term, seasonal sampling was conducted at a single site near Charleston, South Carolina, to determine relative abundance and timing of recruitment of Penaeus postlarvae. This study is part of a continuing effort to relate postlarval abundance to subsequent landings and to evaluate spawning success of parental stocks