11,881 research outputs found
THE DISTRIBUTIONAL EFFECTS OF LAND CONTROLS IN AGRICULTURE
The paper introduces a framework for analyzing the impacts of land control programs on agricultural production under heterogenous land qualities, heterogenous production technologies and imperfect capital markets. It shows that the introduction of diversion programs tends to benefit land owners while harming operators. Moreover, it tends to increase the separation of land ownership and operation and increase concentration among operators. Diversion programs tend to raise land prices lass than proportional to the increases in rental rates. They encourage the adoption of yield increasing technologies, and may also encourage adoption of cost reducing technologies when credit is a binding constraint. Participation in voluntary government programs tends to be greater in regions with higher costs, less efficient marginal technology and less efficient marginal land.Land Economics/Use,
Transient complete heart block following catheter ablation of a left lateral accessory pathway.
A 16-year-old female with symptomatic Wolff-Parkinson-White (WPW) syndrome underwent catheter ablation of a left-sided lateral accessory pathway. The accessory pathway was eliminated with the first ablation lesion; however, the patient immediately developed complete heart block (CHB). At first, complete heart block was thought to be due to ablation of left atrial extension of the AV node, and pacemaker therapy was considered. However, careful ECG analysis revealed that the development of CHB was in fact due to bump injury to the AV node during transseptal catheterization. Conservative management allowed resolution of AV nodal conduction without need for a permanent pacemaker
Compensation and Political Feasibility: Facilitating Welfare Improving Policies
There is a broad consensus among economists, policymakers, and informed citizens that free-market economics do not preclude many inefficiencies in resource allocation. There are many circumstances where policy interventions have the potential to achieve a Pareto improvement in the sense of making some people better off without making others worse off. The challenge to any particular market-oriented society is to design those mechanisms, organizations and institutions that identify the limitations of free-markets and result in those reforms that seek Pareto-improved outcomes
Evaluating the climate effects of mid-1800s deforestation in New England, USA, using a Weather, Research, and Forecasting (WRF) Model Multi-Physics Ensemble
The New England region of the northeastern United States has a land use history characterized by forest clearing for agriculture and other uses during European colonization and subsequent reforestation following widespread farm abandonment. Despite these broad changes, the potential influence on local and regional climate has received relatively little attention. This study investigated wintertime (December through March) climate impacts of reforestation in New England using a high-resolution (4 km) multiphysics ensemble of the Weather Research and Forecasting Model. In general, the conversion from mid-1800s cropland/grassland to forest led to warming, but results were sensitive to physics parameterizations. The 2-m maximum temperature (T2max) was most sensitive to choice of land surface model, 2-m minimum temperature (T2min) was sensitive to radiation scheme, and all ensemble members simulated precipitation poorly. Reforestation experiments suggest that conversion of mid-1800s cropland/grassland to present-day forest warmed T2max +0.5 to +3 K, with weaker warming during a warm, dry winter compared to a cold, snowy winter. Warmer T2max over forests was primarily the result of increased absorbed shortwave radiation and increased sensible heat flux compared to cropland/grassland. At night, T2min warmed +0.2 to +1.5 K where deciduous broadleaf forest replaced cropland/grassland, a result of decreased ground heat flux. By contrast, T2min of evergreen needleleaf forest cooled –0.5 to –2.1 K, primarily owing to increased ground heat flux and decreased sensible heat flux
A Framework for Analyzing Specific Agricultural Policy Reform
The agricultural sectors of the United States and other developed countries have been subjected to a myriad of policies and regulations that have contributed to unsatisfactory production patterns and resource allocations both within and between countries. Furthermore, such policies have imposed heavy financial burdens on governments that have transferred substantial resources to support the farm sector. The General Agreement on Tariffs and Trade (GATT) strives to improve the efficiency of agricultural trade and production patterns globally. It is proposed that GATT will reduce the set of permissible agricultural policy instruments, thereby eliminating some policy options that have contributed to several of the undesired consequences of the past. Used correctly, the feasible set of policies is believed to allow for a gradual down scaling of agriculture\u27s excess supply and to make the sector more flexible and progressive. Ultimately, once the restricted set of policies is introduced, it is expected that a sustainable growth path will be achieved
An X-ray measurement of Titan's atmospheric extent from its transit of the Crab Nebula
Saturn's largest satellite, Titan, transited the Crab Nebula on 5 January
2003. We observed this astronomical event with the {\it Chandra} X-ray
Observatory. An ``occultation shadow'' has clearly been detected and is found
to be larger than the diameter of Titan's solid surface. The difference gives a
thickness for Titan's atmosphere of 880 60 km. This is the first
measurement of Titan's atmospheric extent at X-ray wavelengths. The value
measured is consistent with or slightly larger than those estimated from
earlier Voyager observations at other wavelengths. We discuss the possibility
of temporal variations in the thickness of Titan's atmosphere.Comment: 14 pages, 5 figures, AASTeX preprint. Accepted for publication in the
Astrophysical Journa
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