7,669 research outputs found

    Tobacco Farmer Interest and Success in Income Diversification

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    As farm income from tobacco production has declined in recent years, there has been increasing interest in identifying alternative sources of income for tobacco farmers in the southern United States The recent termination of the tobacco quota program has accelerated the exit of tobacco farmers and has heightened concern regarding the availability of substitutes for tobacco production. In this study, we examine factors influencing tobacco farmers’ attempts to identify profitable alternatives to tobacco, their off-farm employment behavior, and changes in acres of tobacco cultivated using survey data collected from a panel of North Carolina tobacco farmers combined with market datadiversification, farm programs, farmer survey, quota buyout, tobacco, Crop Production/Industries, Farm Management, Financial Economics, C33, Q12, Q18,

    Tobacco Farmer Interest and Success in Diversification

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    As U.S. farm income from tobacco production has declined in recent years, there has been increased interest in developing alternative sources of farm revenue to replace lost tobacco income, particularly in tobacco-dependent communities of the southeastern United States. The recent end of the tobacco quota program is expected to accelerate the exit of tobacco farmers and has heightened concern regarding the availability of profitable substitutes for tobacco. In this study, we examine the impact of farm, household, and market characteristics on tobacco farmer interest and success in on-farm and off-farm income diversification. Using survey data collected from a panel of North Carolina tobacco farmers in 1997, 1999, 2001, and 2004 combined with market data collected from secondary sources, we evaluate the influence of farmer preferences, resource endowments, market incentives, risk, and biophysical factors on tobacco farmers' attitudes regarding diversification into non-tobacco products, the extent to which they reallocated resources towards non-tobacco products, and their success in identifying profitable alternatives to tobacco production. Our research contributes empirical findings to the public dialogue concerning the ability of tobacco farmers and tobacco-dependent communities to adjust to structural changes taking place in the tobacco market.Tobacco, farm diversification, household model, quota buyout., Farm Management,

    The Impact of a Community Awareness Strategy on Caregiver Treatment Seeking Behaviour and Use of Artemether-Lumefantrine for Febrile Children in Rural Kenya.

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    BACKGROUND: Access to prompt and effective treatment is the cornerstone for malaria control. Population Services International in collaboration with the Ministry of Health launched a malaria behaviour change communication intervention in Nyanza province, Kenya. The initiative aimed to improve: symptom recognition and prompt access to government health facilities for febrile children; effective treatment with the recommended first-line drug artemether-lumefantrine (AL) in public health facilities and adherence to the AL regimen. METHODS: Pre- and post-intervention cross-sectional household surveys were used to evaluate the impact of the intervention on prompt and correct use of AL for febrile children below five years of age. The primary outcome was the proportion of children below five years of age with fever in the last 14 days accessing AL within 48 hours of fever onset. RESULTS: There was an increase from 62.8% pre-intervention to 79.4% post-intervention (95% CI: 11.1, 22.1) in caregivers who reported seeking formal treatment promptly (on the same day, or next day) for their febrile children. However, there was a decrease in the use of government health facilities in the post-intervention period. There was a small increase in the proportion of children accessing AL within 48 hours of fever onset [18.4% vs 23.5% (0.1-10.0)]. CONCLUSION: The findings of this evaluation demonstrate that interventions that target only one sector may have a limited impact on improvements in prompt and effective treatment where multiple sources of treatments are sought for febrile illness. Additionally, the context in which an intervention is implemented is likely to influence the process and outcomes

    Dust and the spectral energy distribution of the OH/IR star OH 127.8+0.0: Evidence for circumstellar metallic iron

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    We present a fit to the spectral energy distribution of OH 127.8+0.0, a typical asymptotic giant branch star with an optically thick circumstellar dust shell. The fit to the dust spectrum is achieved using non-spherical grains consisting of metallic iron, amorphous and crystalline silicates and water ice. Previous similar attempts have not resulted in a satisfactory fit to the observed spectral energy distributions, mainly because of an apparent lack of opacity in the 3--8 micron region of the spectrum. Non-spherical metallic iron grains provide an identification for the missing source of opacity in the near-infrared. Using the derived dust composition, we have calculated spectra for a range of mass-loss rates in order to perform a consistency check by comparison with other evolved stars. The L-[12 micron] colours of these models correctly predict the mass-loss rate of a sample of AGB stars, strengthening our conclusion that the metallic iron grains dominate the near-infrared flux. We discuss a formation mechanism for non-spherical metallic iron grains.Comment: 10 pages, 6 figures, accepted for publication by A&

    Normal levels of p27Xic1 are necessary for somite segmentation and determining pronephric organ size

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    The Xenopus laevis cyclin dependent kinase inhibitor p27Xic1 has been shown to be involved in exit from the cell cycle and differentiation of cells into a quiescent state in the nervous system, muscle tissue, heart and retina. We show that p27Xic1 is expressed in the developing kidney in the nephrostomal regions. Using over-expression and morpholino oligonucleotide (MO) knock-down approaches we show normal levels of p27Xic1 regulate pronephros organ size by regulating cell cycle exit. Knock-down of p27Xic1 expression using a MO prevented myogenesis, as previously reported; an effect that subsequently inhibits pronephrogenesis. Furthermore, we show that normal levels of p27Xic1 are required for somite segmentation also through its cell cycle control function. Finally, we provide evidence to suggest correct paraxial mesoderm segmentation is not necessary for pronephric induction in the intermediate mesoderm. These results indicate novel developmental roles for p27Xic1, and reveal its differentiation function is not universally utilised in all developing tissues

    Optical spectrum of proflavine and its ions

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    Motivated by possible astrophysical and biological applications we calculate visible and near UV spectral lines of proflavine (C13H11N3, 3,6-diaminoacridine) in vacuum, as well as its anion, cation, and dication. The pseudopotential density functional and time-dependent density functional methods are used. We find a good agreement in spectral line positions calculated by two real-time propagation methods and the Lanczos chain method. Spectra of proflavine and its ions show characteristic UV lines which are good candidates for a detection of these molecules in interstellar space and various biological processes

    The global dust SED: Tracing the nature and evolution of dust with DustEM

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    The Planck and Herschel missions are currently measuring the farIR-mm emission of dust, which combined with existing IR data, will for the first time provide the full SED of the galactic ISM dust emission with an unprecedented sensitivity and angular resolution. It will allow a systematic study of the dust evolution processes that affect the SED. Here we present a versatile numerical tool, DustEM, that predicts the emission and extinction of dust given their size distribution and their optical and thermal properties. In order to model dust evolution, DustEM has been designed to deal with a variety of grain types, structures and size distributions and to be able to easily include new dust physics. We use DustEM to model the dust SED and extinction in the diffuse interstellar medium at high-galactic latitude (DHGL), a natural reference SED. We present a coherent set of observations for the DHGL SED. The dust components in our DHGL model are (i) PAHs, (ii) amorphous carbon and (iii) amorphous silicates. We use amorphous carbon dust, rather than graphite, because it better explains the observed high abundances of gas-phase carbon in shocked regions of the interstellar medium. Using the DustEM model, we illustrate how, in the optically thin limit, the IRAS/Planck HFI (and likewise Spitzer/Herschel for smaller spatial scales) photometric band ratios of the dust SED can disentangle the influence of the exciting radiation field intensity and constrain the abundance of small grains relative to the larger grains. We also discuss the contributions of the different grain populations to the IRAS, Planck and Herschel channels. Such information is required to enable a study of the evolution of dust as well as to systematically extract the dust thermal emission from CMB data and to analyze the emission in the Planck polarized channels. The DustEM code described in this paper is publically available.Comment: accepted for publication in A&

    High-Efficiency Resonant RF Spin Rotator with Broad Phase Space Acceptance for Pulsed Polarized Cold Neutron Beams

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    We have developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to RF neutron spin flippers based on adiabatic fast passage. The spin rotator does not change the kinetic energy of the neutrons and leaves the neutron beam phase space unchanged to high precision. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically-polarized 3He neutron spin filters. The efficiency of the spin rotator was measured to be 98.0+/-0.8% on resonance for neutron energies from 3.3 to 18.4 meV over the full phase space of the beam. As an example of the application of this device to an experiment we describe the integration of the RF spin rotator into an apparatus to search for the small parity-violating asymmetry A_gamma in polarized cold neutron capture on para-hydrogen by the NPDGamma collaboration at LANSCE

    Neutron cross sections for He-3 at epithermal energies

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    High accuracy, absolute measurements of the neutron total cross section for He-3 are reported for incident neutron energies 0.1-400 eV. The measurements were performed at the LANSCE short-pulse neutron spallation source. Using the previously determined cross section for neutron elastic scattering, 3.367+/-0.019 b, we extract a new value for the energy dependence of the He-3(n,p)He-3 reaction cross section, sigma(np)=(849.77+/-0.14+/-1.02)E-1/2-(1.253+/-0.00+/-(+0.008)(-0.049))b, where the neutron energy is expressed in eV. The first uncertainty is statistical, the second systematic
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