264 research outputs found
Regional Agricultural Policy Design on the Basis of a Detailed Linear Economic and Agrotechnical Model
The use of a large-scale LP agricultural model for supporting the policy design process is presented. The model determines the agricultural crop and livestock specialization in a detailed, disaggregated form, i.e. distributed over subregions, properties, sail qualities, technologies, etc. and basic financial and material flaws, all in given natural conditions, e.g. sail qualities, and available resources, e.g. manpower, machinery, capital, etc. The policy is meant in terms of imposed price structure and resource distribution. The use of information obtainable from both primal and dual solution is shown. The results of implementation for a region in Poland are presented
An in vivo root hair assay for determining rates of apoptotic-like programmed cell death in plants
In Arabidopsis thaliana we demonstrate that dying root hairs provide an easy and rapid in vivo model for the morphological identification of apoptotic-like programmed cell death (AL-PCD) in plants. The model described here is transferable between species, can be used to investigate rates of AL-PCD in response to various treatments and to identify modulation of AL-PCD rates in mutant/transgenic plant lines facilitating rapid screening of mutant populations in order to identify genes involved in AL-PCD regulation
Light Influences How the Fungal Toxin Deoxynivalenol Affects Plant Cell Death and Defense Responses
The Fusarium mycotoxin deoxynivalenol (DON) can cause cell death in wheat (Triticum aestivum), but can also reduce the level of cell death caused by heat shock in Arabidopsis (Arabidopsis thaliana) cell cultures. We show that 10 ÎŒg mLâ1 DON does not cause cell death in Arabidopsis cell cultures, and its ability to retard heat-induced cell death is light dependent. Under dark conditions, it actually promoted heat-induced cell death. Wheat cultivars differ in their ability to resist this toxin, and we investigated if the ability of wheat to mount defense responses was light dependent. We found no evidence that light affected the transcription of defense genes in DON-treated roots of seedlings of two wheat cultivars, namely cultivar CM82036 that is resistant to DON-induced bleaching of spikelet tissue and cultivar Remus that is not. However, DON treatment of roots led to genotype-dependent and light-enhanced defense transcript accumulation in coleoptiles. Wheat transcripts encoding a phenylalanine ammonia lyase (PAL) gene (previously associated with Fusarium resistance), non-expressor of pathogenesis-related genes-1 (NPR1) and a class III plant peroxidase (POX) were DON-upregulated in coleoptiles of wheat cultivar CM82036 but not of cultivar Remus, and DON-upregulation of these transcripts in cultivar CM82036 was light enhanced. Light and genotype-dependent differences in the DON/DON derivative content of coleoptiles were also observed. These results, coupled with previous findings regarding the effect of DON on plants, show that light either directly or indirectly influences the plant defense responses to DON
A General Regional Agricultural Model (GRAM) Applied to a Region in Poland
The General Regional Agricultural Model (GRAM) described in this report is the product of a case study of regional development in the Upper Notec region of Poland carried out collaboratively by IIASA and the Systems Research Institute in Warsaw, Poland. The purpose of this work was twofold: to assist Polish authorities in planning the development of agriculture in the region, and to create a universal methodology in the form of a model applicable to similar problems and settings in other countries. Thus, the methodological characteristics presented in this report are based on testing and implementing the model in the concrete situation of the Upper Notec region of Poland.
GRAM was developed using the so-called "bottom-up" approach, which consists of orienting the model toward technological interdependencies at the level of the agricultural areas in the region, and including a set of variables and parameters that enable this "bottom" model to be linked with those for other aspects of the regional economy.
The model deals with the following elements: a set of crops, a number of rotation groups; types of agricultural animals, types of livestock products, and feed components in forage; three types of market and three types of land ownership; different crop growing and livestock breeding technologies; and different soil qualities and types of fertilizers according to the contents of the elements. The model incorporates space and can give solutions for a number of regions. Technically GRAM is a large linear programming model with static relations.
The purpose of the model is to derive a detailed specification for a production structure combined with a direct utilization of its products that is optimal for a predefined objective. The model can also be used to indicate essential bottlenecks, resource distribution inconsistencies, and so on. It allows the formulations of multi-objective optimization problems to consider conflicts between different groups of producers. It is solved under constraints in labor, machinery, fertilizers and water availability at annual and two peak levels.
Two types of objective functions are used: monetary (linked with cost-benefit analysis) and physical. Among specific objective for which the model has been solved there are: total net return or net production value from agricultural activities within the region; balance of regional agricultural production in monetary terms; regional agricultural production in terms of nutrition units; regional trade balances in livestock products in monetary terms and nutrition units; and export production in monetary terms. In cooperation with other elements of the regional model system, two types of information are exchanged: dual prices and volume of output
An approach to automatic learning assessment based on the computational theory of perceptions
E-learning systems output a huge quantity of data on a learning process. However, it takes a lot of specialist
human resources to manually process these data and generate an assessment report. Additionally, for formative assessment, the report should state the attainment level of the learning goals defined by the instructor. This paper describes the use of the granular linguistic model of a phenomenon (GLMP) to model the assessment of the learning process and implement the automated generation of an assessment report. GLMP is based on fuzzy logic and the computational theory of perceptions. This technique is useful for implementing complex assessment criteria using inference systems based on linguistic rules. Apart from
the grade, the model also generates a detailed natural language progress report on the achieved proficiency level, based exclusively on the objective data gathered from correct and incorrect responses. This is illustrated by applying the model to the assessment of Dijkstraâs algorithm learning using a visual simulation-based graph algorithm learning environment, called GRAPH
Logarithmic aggregation operators and distance measures
The Hamming distance is a wellâknown measure that is designed to provide insights into the similarity between two strings of information. In this study, we use the Hamming distance, the optimal deviation model, and the generalized ordered weighted logarithmic averaging (GOWLA) operator to develop the ordered weighted logarithmic averaging distance (OWLAD) operator and the generalized ordered weighted logarithmic averaging distance (GOWLAD) operator. The main advantage of these operators is the possibility of modeling a wider range of complex representations of problems under the assumption of an ideal possibility. We study the main properties, alternative formulations, and families of the proposed operators. We analyze multiple classical measures to characterize the weighting vector and propose alternatives to deal with the logarithmic properties of the operators. Furthermore, we present generalizations of the operators, which are obtained by studying their weighting vectors and the lambda parameter. Finally, an illustrative example regarding innovation project management measurement is proposed, in which a multiâexpert analysis and several of the newly introduced operators are utilized
A new measure of volatility using induced heavy moving averages
The volatility is a dispersion technique widely used in statistics and economics. This paper presents a new way to calculate volatility by using different extensions of the ordered weighted average (OWA) operator. This approach is called the induced heavy ordered weighted moving average (IHOWMA) volatility. The main advantage of this operator is that the classical volatility formula only takes into account the standard deviation and the average, while with this formulation it is possible to aggregate information according to the decision maker knowledge, expectations and attitude about the future. Some particular cases are also presented when the aggregation information process is applied only on the standard deviation or on the average. An example in three different exchange rates for 2016 are presented, these are for: USD/MXN, EUR/MXN and EUR/USD
Growing old, yet staying young: The role of telomeres in bats' exceptional longevity
Understanding aging is a grand challenge in biology. Exceptionally long-lived animals have mechanisms that underpin extreme longevity. Telomeres are protective nucleotide repeats on chromosome tips that shorten with cell division, potentially limiting life span. Bats are the longest-lived mammals for their size, but it is unknown whether their telomeres shorten. Using >60 years of cumulative mark-recapture field data, we show that telomeres shorten with age inRhinolophus ferrumequinumandMiniopterus schreibersii, but not in the bat genus with greatest longevity,Myotis. As in humans, telomerase is not expressed inMyotis myotisblood or fibroblasts. Selection tests on telomere maintenance genes show thatATMandSETX, which repair and prevent DNA damage, potentially mediate telomere dynamics inMyotisbats. Twenty-one telomere maintenance genes are differentially expressed inMyotis, of which 14 are enriched for DNA repair, and 5 for alternative telomere-lengthening mechanisms. We demonstrate how telomeres, telomerase, and DNA repair genes have contributed to the evolution of exceptional longevity inMyotisbats, advancing our understanding of healthy aging
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