90 research outputs found
Recent Structural Change in the U.S. Farm Sector: A Household Income Equivalency Perspective
Structural change in the U.S. farm sector remains a source of continuing national interest. This interest has been heightened recently by concern over vertical integration and the passage of a new farm bill. Structural change is commonly examined in terms of the scale of the farm, such as the dollar value of sales or the number of acres farmed. However, to many farmers and non-farmers, structural change is not about physical or financial scale, but about the ability of the farm to provide an acceptable standard of living relative to other Americans. In this article, we use a household income equivalency perspective to examine recent changes in farm structure. The picture which emerges differs from the conventionally accepted story in several respects
UPDATING CORN PROGRAM PAYMENT YIELDS: ARE FARM OPERATORS DIFFERENTIALLY AFFECTED?
Crop yields which determine farm income deficiency payments have been frozen at 1981-1985 levels since 1986. Data from a longitudinal survey of Ohio farm operators are analyzed to evaluate whether updating payment yields will differentially affect farm operators. Results of the analysis imply that farm operators who operate larger farms, live in counties with higher yields, and have higher fertilizer and pesticide expenses per acre of corn will benefit more. In addition, low (high) existing payment yields are understated (overstated) relative to updated payment yields.Agricultural Finance,
Unexpected Economic Loss from Yield Variation and Federal Crop Insurance
Multiple Peril Crop Insurance (MPCl) and GroupRisk Plan (GRP) use yield (i.e., physical) loss to determine who collects. However, insurance is bought to protect against economic loss resulting from physical loss. This study analyzes unexpected economic loss resulting from yield variation. It also compares unexpected economic loss with simulated MPCI and GRP collections for a sample of Ohio farm operators, Analysis reveals: (I) GRP's payout structure is further removed from unexpected economic loss than MPCrs, (2) MPCI collections exceed the associated unexpected economic loss in a free market, and (3) MPCI collections more closely match unexpected loss when farm programs exist
Wnt and Hedgehog Are Critical Mediators of Cigarette Smoke-Induced Lung Cancer
BACKGROUND: Lung cancer is the leading cause of cancer death in the world, and greater than 90% of lung cancers are cigarette smoke-related. Current treatment options are inadequate, because the molecular basis of cigarette-induced lung cancer is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that human primary or immortalized bronchial epithelial cells exposed to cigarette smoke for eight days in culture rapidly proliferate, show anchorage-independent growth, and form tumors in nude mice. Using this model of the early stages of smoke-induced tumorigenesis, we examined the molecular changes leading to lung cancer. We observed that the embryonic signaling pathways mediated by Hedgehog and Wnt are activated by smoke. Pharmacological inhibition of these pathways blocked the transformed phenotype. CONCLUSIONS/SIGNIFICANCE: These experiments provide a model in which the early stages of smoke-induced tumorigenesis can be elicited, and should permit us to identify molecular changes driving this process. Results obtained so far indicate that smoke-induced lung tumors are driven by activation of two embryonic regulatory pathways, Hedgehog (Hh) and Wnt. Based on the current and emerging availability of drugs to inhibit Hh and Wnt signaling, it is possible that an understanding of the role of Hh and Wnt in lung cancer pathogenesis will lead to the development of new therapies
Recommended from our members
A proposed framework for the systematic review and integrated assessment (SYRINA) of endocrine disrupting chemicals
Background - The issue of endocrine disrupting chemicals (EDCs) is receiving wide attention from both the scientific and regulatory communities. Recent analyses of the EDC literature have been criticized for failing to use transparent and objective approaches to draw conclusions about the strength of evidence linking EDC exposures to adverse health or environmental outcomes. Systematic review methodologies are ideal for addressing this issue as they provide transparent and consistent approaches to study selection and evaluation. Objective methods are needed for integrating the multiple streams of evidence (epidemiology, wildlife, laboratory animal, in vitro, and in silico data) that are relevant in assessing EDCs.
Methods - We have developed a framework for the systematic review and integrated assessment (SYRINA) of EDC studies. The framework was designed for use with the International Program on Chemical Safety (IPCS) and World Health Organization (WHO) definition of an EDC, which requires appraisal of evidence regarding 1) association between exposure and an adverse effect, 2) association between exposure and endocrine disrupting activity, and 3) a plausible link between the adverse effect and the endocrine disrupting activity.
Results - Building from existing methodologies for evaluating and synthesizing evidence, the SYRINA framework includes seven steps: 1) Formulate the problem; 2) Develop the review protocol; 3) Identify relevant evidence; 4) Evaluate evidence from individual studies; 5) Summarize and evaluate each stream of evidence; 6) Integrate evidence across all streams; 7) Draw conclusions, make recommendations, and evaluate uncertainties. The proposed method is tailored to the IPCS/WHO definition of an EDC but offers flexibility for use in the context of other definitions of EDCs.
Conclusions - When using the SYRINA framework, the overall objective is to provide the evidence base needed to support decision making, including any action to avoid/minimise potential adverse effects of exposures. This framework allows for the evaluation and synthesis of evidence from multiple evidence streams. Finally, a decision regarding regulatory action is not only dependent on the strength of evidence, but also the consequences of action/inaction, e.g. limited or weak evidence may be sufficient to justify action if consequences are serious or irreversible.The workshops that supported the writing of this manuscript were funded by the Swedish Foundation for Strategic Environmental Research “Mistra”. LNV was funded by Award Number K22ES025811 from the National Institute of Environmental Health Sciences of the National Institutes of Health. TJW was funded by The Clarence Heller Foundation (A123547), the Passport Foundation, the Forsythia Foundation, the National Institute of Environmental Health Sciences (grants ES018135 and ESO22841), and U.S. EPA STAR grants (RD83467801 and RD83543301). JT was funded by the Academy of Finland and Sigrid Juselius. UH was funded by the Danish EPA. KAK was funded by the Canada Research Chairs program grant number 950–230607
- …