74,166 research outputs found
Mobile Image Ratiometry for the Detection of Botrytis cinerea (Gray Mold)
Mobile Platform Informatics (MPI) and Smartphone Informatics (SPI) methods like Mobile Image Ratiometry (MIR) are potentially transformative point-of-use instantaneous analysis tools that are useful across a variety of industries. In agriculture, MIR-compatible immuno test strips allow early detection of a number of biotic stressors before devastating crop losses occur. Here we describe a low-cost and easy-to-use Smartphone and/or tablet-based protocol (Mobile Assay Inc., www.mobileassay.com) for the detection and on-sight instantaneous analysis of B. cinerea, a fungus that causes significant damage to a variety of plants and flowers. Early detection and tracking of the B. cinerea fungus before the visible gray mold appears has the potential to increase agricultural productivity especially in the developing world
Sex differences in the associations between birthweight and lipid levels in middle-age: findings from the 1958 British birth cohort
Objective
To examine sex differences in birthweight–lipid associations.
Methods and results
Using prospectively collected data on birthweight and non-fasting lipid levels at age 44–45 y from the 1958 British birth cohort (3603 men and 3583 women), sex differences in birthweight–lipid associations were examined.
There were inverse associations between birthweight and total and low-density-lipoprotein (LDL)-cholesterol among women (a 1 kg increase in birthweight was associated with a 0.13 mmol/L reduction in total cholesterol (p < 0.001) and a 0.07 mmol/L reduction in LDL-cholesterol (p = 0.02)) but no associations among men (p = 0.005 and p = 0.01, respectively, for birthweight × sex interactions). There was an inverse association between birthweight and triglycerides of a similar magnitude in both sexes (a 1 kg increase in birthweight was associated with a 7% reduction in triglyceride levels in sex-adjusted models (p < 0.001)). There was no association between birthweight and high-density-lipoprotein-cholesterol. Associations were largely unaltered after adjustment for covariates. Of birthweight, current height and BMI, the latter was the strongest predictor of lipid levels.
Conclusions
The finding of an inverse association between birthweight and triglycerides in both sexes and of inverse associations between birthweight and total and LDL-cholesterol only in women suggests that the mechanisms underlying the associations with birthweight may vary for different lipids
Knowledge transfer in a tourism destination: the effects of a network structure
Tourism destinations have a necessity to innovate to remain competitive in an
increasingly global environment. A pre-requisite for innovation is the
understanding of how destinations source, share and use knowledge. This
conceptual paper examines the nature of networks and how their analysis can
shed light upon the processes of knowledge sharing in destinations as they
strive to innovate. The paper conceptualizes destinations as networks of
connected organizations, both public and private, each of which can be
considered as a destination stakeholder. In network theory they represent the
nodes within the system. The paper shows how epidemic diffusion models can act
as an analogy for knowledge communication and transfer within a destination
network. These models can be combined with other approaches to network analysis
to shed light on how destination networks operate, and how they can be
optimized with policy intervention to deliver innovative and competitive
destinations. The paper closes with a practical tourism example taken from the
Italian destination of Elba. Using numerical simulations the case demonstrates
how the Elba network can be optimized. Overall this paper demonstrates the
considerable utility of network analysis for tourism in delivering destination
competitiveness.Comment: 15 pages, 2 figures, 2 tables. Forthcoming in: The Service Industries
Journal, vol. 30, n. 8, 2010. Special Issue on: Advances in service network
analysis v2: addeded and corrected reference
A Joint Framework for Analysis of Agri-Environmental Payment Programs
This paper presents an approach for simultaneously estimating farmers' decisions to accept incentive payments in return for adopting a bundle of environmentally benign management practices. Using the results of a multinomial probit analysis of surveys of over 1,000 farmers facing ten adoption decisions in an EQIP-type program, we show how the farmers' perceptions of the desirability of various bundles changes with the offer amounts and with which practices are offered in the program.incentive payments, EQIP, simulated multivariate normal, multinomial probit, simulated maximum likelihood estimation, best management practices, Environmental Economics and Policy,
Economic Aspects of Revenue-Based Commodity Support
Interest in revenue-based commodity support is evident in the Food, Conservation and Energy Act of 2008 (the 2008 Farm Bill), which gives eligible producers the option of participating in the Average Crop Revenue Election (ACRE) program in return for reductions and eliminations of payments under more traditional programs. This report examines how the uncertainty in U.S. domestic commodity support payments for corn may differ between traditional-style approaches (defined as price-based payments plus yield-based disaster payments) to support and two revenue-based support scenarios. Variability around the total expected annual payment was found to be lower under revenue-based support, as was the probability of high payments. These results suggest potential advantages to this type of support, both in terms of lower budgetary uncertainty for the Federal Government and in better ensuring that agricultural support outlays stay below a certain ceiling. In addition, the volatility of corn revenue was found to be lower in almost all corn producing counties under the revenue-based alternatives than under the traditional price-based approaches.Domestic commodity support, revenue-based support, marketing loan benefits, countercyclical payments, disaster assistance, Federal crop insurance, Agricultural and Food Policy, Crop Production/Industries, Demand and Price Analysis, Financial Economics,
Hybrid tractability of soft constraint problems
The constraint satisfaction problem (CSP) is a central generic problem in
computer science and artificial intelligence: it provides a common framework
for many theoretical problems as well as for many real-life applications. Soft
constraint problems are a generalisation of the CSP which allow the user to
model optimisation problems. Considerable effort has been made in identifying
properties which ensure tractability in such problems. In this work, we
initiate the study of hybrid tractability of soft constraint problems; that is,
properties which guarantee tractability of the given soft constraint problem,
but which do not depend only on the underlying structure of the instance (such
as being tree-structured) or only on the types of soft constraints in the
instance (such as submodularity). We present several novel hybrid classes of
soft constraint problems, which include a machine scheduling problem,
constraint problems of arbitrary arities with no overlapping nogoods, and the
SoftAllDiff constraint with arbitrary unary soft constraints. An important tool
in our investigation will be the notion of forbidden substructures.Comment: A full version of a CP'10 paper, 26 page
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