PESTICIDE PRODUCTIVITY: WHAT ARE THE TRENDS?

Obtaining estimates of pesticides productivity is an economic response to the growing public concern about the steady increase of pesticide use in the United States. This type of research indicates the cost of limiting pesticide use in terms of foregone output. Pervious empirical studies give a "snap-shot", or "average", look at pesticide productivity. This research effort employs a random coefficient model to determine the trend of the marginal value product of pesticides in agriculture in the United States. Results show a distinct downward trend in two states, Iowa and Texas. California, however, shows no evidence of a downward trend.Pesticide productivity, Marginal value product, Random coefficients, Crop Production/Industries, Productivity Analysis,

Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba(Fe_{1-x}Co_x)_2As_2 Single Crystals using Scanning Tunneling Spectroscopy

Scanning tunneling spectroscopic studies of $Ba(Fe_{1-x}Co_x)_2As_2$ (x = 0.06, 0.12) single crystals reveal direct evidence for predominantly two-gap superconductivity. These gaps decrease with increasing temperature and vanish above the superconducting transition $T_c$. The two-gap nature and the slightly doping- and energy-dependent quasiparticle scattering interferences near the wave-vectors $(\pm \pi, 0)$ and $(0, \pm \pi)$ are consistent with sign-changing $s$-wave superconductivity. The excess zero-bias conductance and the large gap-to-$T_c$ ratios suggest dominant unitary impurity scattering.Comment: 4 pages, 4 figures. Paper accepted for publication in Physical Review Letters. Contact author: Nai-Chang Yeh ([email protected]

Advances in fidelity measurement for mental health services research

The official published article is available online at http://doi.org/10.1176/appi.ps.201100430.OBJECTIVE: Mental health intervention research requires clear and accurate specification of treatment conditions in intervention studies. Measures are increasingly available for community-based interventions for persons with serious mental illnesses. Measures must go beyond structural features to assess critical processes in interventions. They must also balance effectiveness, adequate coverage of active treatment elements, with efficiency, the degree to which measures may be used cost-effectively. The context of their use is changing with the emergence of new frameworks for implementation research and quality improvement. METHODS: The focus, content, and results of preliminary studies of four recently developed fidelity measures are described. Measures respectively assess fidelity to case management, cognitive therapy for psychosis, illness management and recovery, and assertive community treatment. RESULTS: Fidelity measures described assess interventions in a range of treatment contexts from dyads to teams. Each measure focuses assessment resources on the elements critical to the respective intervention. Each has demonstrated coverage of its target intervention and satisfactory psychometric properties and is related to outcomes. Measures have been used for training, quality improvement, or certification. Current fidelity measures assess domains and have uses beyond their nominal position in implementation and quality frameworks. CONCLUSION: Process components in community-based interventions can be effectively assessed in fidelity measures. Omission of elements assessing potentially critical, active treatment components poses risk to both research and practice until there is evidence to demonstrate they are non-essential. Further development of fidelity measurement theory and approaches should articulate with development of theory and methods in implementation science

Sworn oath to not provide liquor to slaves; liquor license.

John F. Cutter attests to not provide or sell liquor to any slaves. Aiken, Barnwell District, South Carolina, 1859.https://digitalcommons.wofford.edu/littlejohnmss/1317/thumbnail.jp

Comparative studies of the scanning tunneling spectra in cuprate and iron-arsenide superconductors

We report scanning tunneling spectroscopic studies of cuprate and iron-arsenic superconductors, including YBa_2Cu_3O_{7-\delta} (Y-123, T_c = 93 K), Sr_{0.9}La_{0.1}CuO_2 (La-112, T_c = 43 K), and the "122" compounds Ba(Fe_{1-x}Co_x)_2As_2 (Co-122 with x = 0.06, 0.08, 0.12 for T_c = 14, 24, 20 K). For H > 0, pseudogap (\Delta_{PG}) features are revealed inside the vortices, with \Delta_{PG} = [(\Delta_{eff})^2+(\Delta_{SC})^2]^{1/2} > \Delta_{SC} in Y-123 and \Delta_{PG} < \Delta_{SC} in La-112, suggesting that the physical origin of \Delta_{PG} is a competing order coexisting with superconductivity. Additionally, Fourier transformation (FT) of the Y-123 spectra exhibits two types of spectral peaks, one type is associated with energy (\omega)-dependent quasiparticle interference (QPI) wave-vectors and the other consists of \omega-independent wave-vectors due to competing orders and (\pi,\pi) magnetic resonances. For the multi-band Co-122 compounds, two-gap superconductivity is found for all doping levels. Magnetic resonant modes that follow the temperature dependence of the superconducting gaps are also identified. These findings, together with the \omega- and x-dependent QPI spectra, are consistent with a sign-changing s-wave pairing symmetry in the Co-122 iron arsenides. Our comparative studies suggest that the commonalities among the cuprate and the ferrous superconductors include the proximity to competing orders, antiferromagnetic (AFM) spin fluctuations and magnetic resonances in the superconducting (SC) state, and the unconventional pairing symmetries with sign-changing order parameters on different parts of the Fermi surface.Comment: 6 pages, 3 figures. Submitted to Journal of Physics: Conference Proceedings for the 26th International Low-Temperature Conference (2011). Corresponding author: Nai-Chang Yeh ([email protected]