4,720 research outputs found
Slippage Effects of the Conservation Reserve Program: New Evidence from Satellite Imagery
The Conservation Reserve Program (CRP) is the largest land retirement program ever operated in the US. Since its inception in 1985, many researchers have studied the impacts of this program; however, only a few have analyzed how the CRP affects surrounding nonâenrolled parcels. In this research I examine how the CRP may affect the conversion of nonâcropped land to agriculture, a phenomenon referred to as âslippageâ in the literature, and specifically addressed by Wu (2000) and Roberts and Bucholtz (2005). Building on these earlier studies, I empirically model slippage using data derived from satellite imagery that provides information on land cover changes between 1992 and 2001. The study area consists of 1,053 counties located in the Northern Plains, Corn Belt and Lake States regions. Results support the existence of slippage effects from the CRP, but they are more conservative than the ones found by Wu (2000). The evidence of slippage provided here is important information for planners, given that whether and how the CRP affects land use decisions in surrounding areas is key information for implementing conservation efforts more efficiently.CRP, Land use change, Satellite imagery, Slippage effect, Agricultural and Food Policy, Land Economics/Use, Q15, Q24,
Experiments on dynamic stiffness and damping of tapered bore seals
Stiffness and damping were measured in tapered bore ring seals with air as the sealed fluid. Excitation was provided by a known unbalance in the shaft which rotated in the test seals. Results were obtained for various seal supply pressures, clearances, unbalance amounts, and shaft speeds. Stiffness and damping varied little with unbalance level, indicating linearity of the seal. Greater variation was observed with speed and particularly supply pressure. A one-dimensional analysis predicted stiffness fairly well, but considerably overestimated damping
Magnetic bearings-state of the art
Magnetic bearings have existed for many years, at least in theory. Earnshaw's theorem, formulated in 1842, concerns stability of magnetic suspensions, and states that not all axes of a bearing can be stable without some means of active control. In Beam's widely referenced experiments, a tiny (1/64 in diameter) rotor was rotated to the astonishing speed of 800,000 rps while it was suspended in a magnetic field. Despite a long history, magnetic bearings have only begun to see practical application since about 1980. The development that finally made magnetic bearings practical was solid state electronics, enabling power supplies and controls to be reduced in size to where they are now comparable in volume to the bearings themselves. An attempt is made to document the current (1991) state of the art of magnetic bearings. The referenced papers are large drawn from two conferences publications published in 1988 and 1990 respectively
The limits of deontology in dental ethics education
Most current dental ethics curricula use a deontological approach to biomedical
and dental ethics that emphasizes adherence to duties and principles as properties
that determine whether an act is ethical. But the actual ethical orientation of students is
typically unknown. The purpose of the current study was to determine the ethical
orientation of dental students in resolving clinical ethical dilemmas. First-year students
from one school were invited to participate in an electronic survey that included eight
vignettes featuring ethical conflicts common to the health care setting. The
Multidimensional Ethics Scale was used to evaluate the studentsâ ethical judgments
of these conflicts. Students rated each vignette along 13 ethically relevant items using a
7-point scale. Nine of the thirteen items were analyzed because they represent the
dominant ethical theories, including deontology. One hundred sixteen dental students
successfully completed the survey. Of the analyzed items, those associated with
deontology had comparatively weak associations with whether students judged the
action to be ethical and whether students judged themselves likely to perform the
action. Whether an action was judged to be caring had the strongest association with
whether the action was judged to be ethical and whether students judged themselves
likely to perform the action. These results suggest that adherence to duties or principles
has weaker association with studentsâ ethical judgments and behavior compared to
caring, which was found to be more influential in their ethical judgments and behavior.
Current dental school curricula with a primary focus on deontology may n
Virtual reality urban modelling - an overview
This paper offers an overview of the increasing use of Virtual Reality (VR) technologies for the simulation of urban environments. It provides a summary of cities worldwide where three-dimensional computer modelling is being utilised to aid urban planning. The study considers the need for a digital representation of cities and raises issues pertaining to advantages, barriers and ownership. A case study of a pilot project on the visualisation of Newcastle upon Tyne is examined to show an approach adopted for the representation of this city in North East England. The process of this visualisation is summarised and future research is outlined in relation to this city model
Enzymatic transhalogenation of dendritic RGD peptide constructs with the fluorinase
We thank EPSRC and the Scottish Imaging Network (SINAPSE) for grants. DOâH thanks the Royal Society for a Wolfson Research Merit Award and ST is grateful to the John and Kathleen Watson Scholarship for financial support. We are grateful to Dr Catherine Botting and Dr Sally Shirran of the St Andrews Mass Spectrometry Service for MALDI-MS acquisitions. We also thank Dr Sally Pimlott of the University of Glasgow for the use of radiochemistry facilities. Open access via RSC Gold for Gold.Peer reviewedPublisher PD
Making up for lost time: Forging new connections between health and community development
New trends in the todayâs public health world are making an important case for bringing public health and community development efforts together. These include the changing nature of 21st century preventable disease, the increasing link between health disparities and place, and the early positive evidence from early adopters of combined health and development strategies. Read about specific examples of efforts from King County, Washington that are capitalizing on these changes and simultaneously advancing both health and community development.Community development ; Health
Angular Momentum on the Lattice: The Case of Non-Zero Linear Momentum
The irreducible representations (IRs) of the double cover of the Euclidean
group with parity in three dimensions are subduced to the corresponding cubic
space group. The reduction of these representations gives the mapping of
continuum angular momentum states to the lattice in the case of non-zero linear
momentum. The continuous states correspond to lattice states with the same
momentum and continuum rotational quantum numbers decompose into those of the
IRs of the little group of the momentum vector on the lattice. The inverse
mapping indicates degeneracies that will appear between levels of different
lattice IRs in the continuum limit, recovering the continuum angular momentum
multiplets. An example of this inverse mapping is given for the case of the
``moving'' isotropic harmonic oscillator.Comment: v3) Little groups for lattice momenta corrected. Includes corrections
from erratum submitted to Phys. Rev. D and a more consistent labeling scheme.
v2) Minor changes to little groups. (9 pages
Animal Efficiency in an Intensive Beef Production System
A stochastic input distance function is estimated to analyse the efficiency with which physical characteristics of individual lot-fed beef cattle in Australia are combined with conventional inputs to produce a final product possessing defined quality attributes. High mean technical efficiency estimates are reported for all animals and by breed. All partial output elasticities with respect to inputs are of expected sign. Of four outputs included in the analysis, carcass weight and moisture retention in meat after cooking have highly significant coefficients of expected sign, but two meat quality variables have coefficients of unexpected sign indicating that they decline as inputs increase. Some evidence is detected of scope economies between moisture retention in meat and the inverse of meat compression.efficiency, intensive agriculture, scope economies, Livestock Production/Industries, Q12, C51,
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