11,441 research outputs found
IMPACTS OF THE ADOPTION OF GENETICALLY ENGINEERED CROPS ON FARM FINANCIAL PERFORMANCE
The rapid adoption of genetically engineered (GE) crops by U.S. farmers suggests that these technologies have been perceived to improve farm financial performance. This study develops and applies an econometric model to data from corn and soybean producers in order to evaluate the financial impacts of the adoption of GE crops. Results indicate that the adoption of GE crops has had a limited impact on financial performance that varies by crop, type of technology, type of farm, and region of the nation. Factors other than the financial impacts appear to be important reasons for the rapid adoption of GE crops.Bt, corn, farm financial performance, genetically engineered crops, herbicide-tolerant, soybeans, technology adoption, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,
PRODUCTION AND FINANCIAL IMPACTS OF THE ADOPTION OF BOVINE SOMATOTROPIN ON U.S. DAIRY FARMS
Production and financial impacts of recombinant bovine somatotropin (rbST) adoption are assessed using a survey of U.S. dairy operations and a model that corrects for self-selection bias. A substantial increase in milk production per cow is associated with rbST adoption, but large estimated financial impacts are not statistically significant. Substantial variation in the net returns of rbST adopters may be related to the management-intensive nature of rbST.Livestock Production/Industries,
Pitot pressure in hypersonic flow with condensation.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76722/1/AIAA-6518-763.pd
Variation in compulsory psychiatric inpatient admission in England:a cross-sectional, multilevel analysis
Background: Rates of compulsory admission have increased in England in recent decades, and this trend is accelerating. Studying variation in rates between people and places can help identify modifiable causes. Objectives: To quantify and model variances in the rate of compulsory admission in England at different spatial levels and to assess the extent to which this was explained by characteristics of people and places. Design: Cross-sectional analysis using multilevel statistical modelling. Setting: England, including 98% of Census lower layer super output areas (LSOAs), 95% of primary care trusts (PCTs), 93% of general practices and all 69 NHS providers of specialist mental health services. Participants: 1,287,730 patients. Main outcome measure: The study outcome was compulsory admission, defined as time spent in an inpatient mental illness bed subject to the Mental Health Act (2007) in 2010/11. We excluded patients detained under sections applying to emergency assessment only (including those in places of safety), guardianship or supervision of community treatment. The control group comprised all other users of specialist mental health services during the same period. Data sources: The Mental Health Minimum Data Set (MHMDS). Data on explanatory variables, characterising each of the spatial levels in the data set, were obtained from a wide range of sources, and were linked using MHMDS identifiers. Results: A total of 3.5% of patients had at least one compulsory admission in 2010/11. Of (unexplained) variance in the null model, 84.5% occurred between individuals. Statistically significant variance occurred between LSOAs [6.7%, 95% confidence interval (CI) 6.2% to 7.2%] and provider trusts (6.9%, 95% CI 4.3% to 9.5%). Variances at these higher levels remained statistically significant even after adjusting for a large number of explanatory variables, which together explained only 10.2% of variance in the study outcome. The number of provider trusts whose observed rate of compulsory admission differed from the model average to a statistically significant extent fell from 45 in the null model to 20 in the fully adjusted model. We found statistically significant associations between compulsory admission and age, gender, ethnicity, local area deprivation and ethnic density. There was a small but statistically significant association between (higher) bed occupancy and compulsory admission, but this was subsequently confounded by other covariates. Adjusting for PCT investment in mental health services did not improve model fit in the fully adjusted models. Conclusions: This was the largest study of compulsory admissions in England. While 85% of the variance in this outcome occurred between individuals, statistically significant variance (around 7% each) occurred between places (LSOAs) and provider trusts. This higher-level variance in compulsory admission remained largely unchanged even after adjusting for a large number of explanatory variables. We were constrained by data available to us, and therefore our results must be interpreted with caution. We were also unable to consider many hypotheses suggested by the service users, carers and professionals who we consulted. There is an imperative to develop and evaluate interventions to reduce compulsory admission rates. This requires further research to extend our understanding of the reasons why these rates remain so high. Funding: The National Institute for Health Research Health Services and Delivery Research programme
GEO debris and interplanetary dust: fluxes and charging behavior
In September 1996, a dust/debris detector: GORID was launched into the
geostationary (GEO) region as a piggyback instrument on the Russian Express-2
telecommunications spacecraft. The instrument began its normal operation in
April 1997 and ended its mission in July 2002. The goal of this work was to use
GORID's particle data to identify and separate the space debris to
interplanetary dust particles (IDPs) in GEO, to more finely determine the
instrument's measurement characteristics and to derive impact fluxes. While the
physical characteristics of the GORID impacts alone are insufficient for a
reliable distinction between debris and interplanetary dust, the temporal
behavior of the impacts are strong enough indicators to separate the
populations based on clustering. Non-cluster events are predominantly
interplanetary, while cluster events are debris. The GORID mean flux
distributions (at mass thresholds which are impact speed dependent) for IDPs,
corrected for dead time, are 1.35x10^{-4} m^{-2} s^{-1} using a mean detection
rate: 0.54 d^{-1}, and for space debris are 6.1x10^{-4} m^{-2} s^{-1} using a
mean detection rate: 2.5 d^{-1}. Beta-meteoroids were not detected. Clusters
could be a closely-packed debris cloud or a particle breaking up due to
electrostatic fragmentation after high charging.Comment: * Comments: 6 pages, 4 postscript figures, in Dust in Planetary
Systems 2005, Krueger, H. and Graps, A. eds., ESA Publications, SP in press
(2006). For high resolution version, see:
http://www.mpi-hd.mpg.de/dustgroup/~graps/dips2005/GrapsetalDIPS2005.pd
The Free-movement pattern Y-maze:A cross-species measure of working memory and executive function
Numerous neurodegenerative and psychiatric disorders are associated with deficits in executive functions, such as working memory and cognitive flexibility. Progress in developing effective treatments for disorders may benefit from targeting these cognitive impairments, the success of which is predicated on the development of animal models with validated behavioural assays. Zebrafish offer a promising model for studying complex brain disorders, but tasks assessing executive function are lacking. The Free movement pattern (FMP) Ymaze combines aspects of the common Y-maze assay, which exploits the inherent motivation of an organism to explore an unknown environment, with analysis based on a series of sequential two-choice discriminations. We validate the task as a measure of working memory and executive function by comparing task performance parameters in adult zebrafish treated with a range of glutamatergic, cholinergic and dopaminergic drugs known to impair working memory and cognitive flexibility. We demonstrate the cross-species validity of the task by assessing performance parameters in adapted versions of the task for mice and Drosophila, and finally a virtual version in humans, and identify remarkable commonalities between vertebrate species’ navigation of the maze. Together, our results demonstrate that the FMP Y-maze is a sensitive assay for assessing working memory and cognitive flexibility across species from invertebrates to humans, providing a simple and widely applicable behavioural assay with exceptional translational relevance
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