6,389 research outputs found
Sensitivity of Rural Housing Values to Aggregate Economic Policy
This paper has a two-fold contribution, 1) Examine the importance of aggregate economic policy on housing prices and rural housing prices, and 2) delineate factors resulting in divergent housing prices between urban and rural markets. Empirical application to US state level data from 1975-2006 indicates general economic variables are consistently influencing both urban and rural housing prices. While the farm economic variables do have differential influences on the housing and rural housing prices, their effects are transitory. Finally regional effects have greater impact on differential effects on urban rural housing price indexes than national farm programs.US state data, rural housing prices, 1975-2007., Community/Rural/Urban Development,
MEASURING SCOPE AND SCALE EFFICIENCY GAINS DUE TO SPECIALIZATION
Using the non-parametric linear programming approach, this study examines overall efficiency gains due to diversification between crop and livestock enterprises for a sample of Kansas farms. Overall efficiency gains were decomposed into scope efficiency gains and scale efficiency gains. Farms with both crops and livestock were found to be less efficient than farms with just crops or just livestock. Operator age, profit margin, and farm size were significantly related to overall efficiency.Farm Management,
Evidence on the need for an integrated approach to the management of diabetes:The diagnostic perspective if osteomyelitis is suspected
Study protocol: Delayed intervention randomised controlled trial within the Medical Research Council (MRC) Framework to assess the effectiveness of a new palliative care service
Background: Palliative care has been proposed to help meet the needs of patients who suffer
progressive non-cancer conditions but there have been few evaluations of service development
initiatives. We report here a novel protocol for the evaluation of a new palliative care service in
this context.
Methods/Design: Using the MRC Framework for the Evaluation of Complex Interventions we
modelled a new palliative care and neurology service for patients severely affected by Multiple
Sclerosis (MS). We conducted qualitative interviews with patients, families and staff, plus a
literature review to model and pilot the service. Then we designed a delayed intervention
randomised controlled trial to test its effectiveness as part of phase II of the MRC framework.
Inclusion criteria for the trial were patients identified by referring clinicians as having unresolved
symptoms or psychological concerns. Referrers were advised to use a score of greater than 8 on
the Expanded Disability Scale was a benchmark. Consenting patients newly referred to the new
service were randomised to either receive the palliative care service immediately (fast-track) or
after a 12-week wait (standard best practice). Face to face interviews were conducted at baseline
(before intervention), and at 4–6, 10–12 (before intervention for the standard-practice group), 16–
18 and 22–24 weeks with patients and their carers using standard questionnaires to assess
symptoms, palliative care outcomes, function, service use and open comments. Ethics committee
approval was granted separately for the qualitative phase and then for the trial.
Discussion: We publish the protocol trial here, to allow methods to be reviewed in advance of
publication of the results. The MRC Framework for the Evaluation of Complex Interventions was
helpful in both the design of the service, methods for evaluation in convincing staff and the ethics
committee to accept the trial. The research will provide valuable information on the effects of
palliative care among non-cancer patients and a method to evaluate palliative care in this context
The Thermodynamic Behavior Of Low-GWP Zeotropic Mixtures On Water-Source Heat Pump Equipment
Regulatory changes, aimed at mitigating climate change, are forcing air-conditioning and heat pump manufacturers to change refrigerants in their products, including all Water-Source Heat Pumps (WSHPs). These changes require substantive changes to WSHP equipment design in order to continue to deliver heat pumps that meet product specifications and energy efficiency regulations. Some of the proposed low-GWP refrigerants to replace R410A, such as R452B and R454A, are zeotropic mixtures of refrigerants. Zeotropes with a significant glide may be taken advantage of in the refrigerant-to-water heat exchanger in a WSHP to improve overall system efficiency. However, there is a potential to also reduce system efficiency if not designed appropriately. This work presents a four-component heat pump model which includes a moving boundary condenser model, lumped element evaporator model, and fixed efficiency compressor model. This model was validated against the data of a R410A water-to-water heat pump operated in heating mode with an average 9.7% MAE in prediction of COP. This model was exercised using R452B and R454A and discovered that the latter provided an opportunity to increase the system COP as a result of the increased enthalpy of vaporization of the fluid. Additionally, the moderate glide that these two refrigerants produce is not significant enough to warrant significant consideration for a water-to-water heat pump
The end of an era:The Population III to Population II transition and the near-infrared background
There are only a few ways to constrain the Era of Reionization and the
properties of high redshift (z>6) stars through observations. Here, we discuss
one of these observables - the spectrum of the Near Infrared Background - and
how it is potentially affected by the transition from Population III to
Population II stars. The stronger Lyman-alpha emission expected from massive
Population III stars could result in a 'bump' in the spectrum of the Near
Infrared Background (referred to in this work as the Lyman-alpha bump). The
strength and shape of this bump can reveal properties of Population III stars.
The Lyman-alpha bump is predicted to be higher if Population III stars are more
massive and present at lower redshifts. The shape of the bump is governed by
the star formation rate and the time it takes Population III stars to
transition to Population II stars. If Population III stars are indeed massive,
a bump is predicted as long as Population III stars exist at z < 15, even if
their star formation rate is as low as 10^-7 M_sun yr^-1 Mpc^-3. This means
that there may be some observational signature in the Near Infrared Background
of small pockets of metal-free gas forming Population III stars at z ~ 6, even
if they are quite rare.Comment: 8 pages, 5 figures, accepted to MNRAS. Clarifications were added and
typos were fixe
Hypotensive Activity of Moringa oleifera Lam (Moringaceae) Root Extracts and its Volatile Constituents
Purpose: To explore the hypotensive activity and chemical composition of Moringa oleifera Lam (Moringaceae) roots.Methods: The fresh roots of M. oleifera was cut into small pieces and successively extracted with petroleum ether (PE) and dichloromethane (DC). PE extract was further divided into MRP and MRP -1. DC extract showed a thick mass during evaporation which was separated as MRDC - IN. The mother liquor left was divided into MRDC and MRDC -1. All residues were analyzed by gas chromatographymass spectroscopy (GC-MS) using ZB-5 column. Identification of each extract and fraction was based on comparison of their retention indices (RI), by co-injecting authentic compounds, as well as by comparing literature data available in NIST Standard Reference Database. Hypotensive activity was determined on urethane-anesthetized normotensive Sprague Dawly rats.Results: Petroleum ether (MRP) and dichloromethane (MRDC) extracts of M. oleifera roots showed 50.06 ± 3.48 and 48.16 ± 1.79 % fall in mean arterial blood pressure (MABP), respectively, at a dose of 30 mg/kg (p < 0.01 and p < 0.05, respectively) compared with control. GC-MS analysis of MRP and MRDC extracts and fractions resulted in the identification of seventy four (74) compounds. Methyl hexadecanoate (7, 20.3 %) , stigmastan - 3, 5, diene (24, 19.32 %), methyl 14-hydroxy-5-tetradecenoate (9, 19.22 %), 1 , 11 diphenyl undecane (47, 18.78 %) and cyclopentanyl hexadecane (39, 14.44 %) were the major constituents among the various hydrocarbons, fatty acids, esters, alcohols, aldehydes, isothiocyanate, aromatics, steroids, terphenyl and sulphur-containing compounds. Conclusion: The findings reveal the hypotensive potential of M. oleifera roots and the presence of specific hydrocarbons, fatty acid esters, thioureides, steroids and isothiocyanates in active fractions. Further study is required to determine the suitability of the plant as an antihypertensive remedy.Keywords: Moringa oleifera, Methyl hexadecanoate, Methyl 14-hydroxy-5-tetradecenoate, Petroleum ether, Stigmastan - 3, 5, diene, Cyclopentanyl hexadecan
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Surface Water Hydrology of the Proposed Low-Level Radioactive Waste Isolation Site, Hudspeth County, Texas
This report describes the surface-water hydrology at the proposed low-level radioactive waste isolation site in Hudspeth County, Texas. The objective of these investigations was to evaluate the flooding potential at the site based on computer simulation of runoff from observed and hypothetical rain events. Analytic techniques and assumptions used in this study are based on recommendations of federal and state regulatory agencies regarding flood insurance and dam safety criteria. Published topographic maps, aerial photographs, and site surveys were used for delineating drainage basins and surface-water pathways on the study area. Surface-water runoff volumes were calculated for rain events monitored at the site during the study period. Hydrologic computer models were employed to determine correlation of rainfall to surface-water runoff. These computer models were calibrated using rainfall and stream-flow data measured at the site. Flood profiles were calculated for 100-yr and probable maximum rain events, which were estimated from historical data. The following conclusions regarding the flooding potential at the study area were drawn on the basis of these studies:
(1) Computer simulation indicates that floods resulting from hypothetical 100-yr and probable maximum precipitation events are contained within existing channels in the study area, leaving large interchannel areas unflooded. Some overland sheet flow is encountered over the flat area, but the velocities of flow are very small.
(2) Rainfall events recorded during the 1988-1989 period were short and localized. The response of runoff to rainfall is rapid and the duration of the peak water flow after rainfall is relatively short.
(3) Flow velocities range from 3 to 13 ft/sec (0.9 to 4 m/sec) in channels and are lower over flat areas. Maximum depth of flow due to a 100-yr flood in the better-defined channel on the central part of the study area is about 5 ft (1.5 m).Bureau of Economic Geolog
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