Modeling adoption of innovations in agriculture using discrete choice models

This paper is concerned with the development of varieties and fertilization techniques of greenhouse tomatoes, and their spatial diffusion in the northwestern region of the Negev in Israel. The main objective of the paper is to identify the factors affecting the farmers’ decision to adopt innovations and the factors inducing the process of knowledge-diffusion in the rural region. The approach adopted is the use of discrete choice models based on random utility theory. Results of the empirical analysis when applying the disaggregate Logit Model indicate that the regional, local and individual attributes have a significant bearing on the farmers’ decision-making process in regard to choosing among alternative tomato varieties and fertilization techniques. The findings indicate that the models constructed for this study may be used as a planning tool for the purpose of evaluating the effect of different factors on the spatial diffusion of innovations in rural regions. The results of the research could also assist decision-makers in formulating development policies for rural regions. Keywords: Spatial diffusion; discrete choice models; greenhouse tomatoes; nested logit

Welfare economic impacts of transportation improvements in a peripheral region

We set out to investigate whether transportation improvements can trigger welfare economic impacts in a peripheral region. The paper addresses this issue through the development of a general equilibrium labor market model with a transportation component. The model is implemented to a set of 101 core and peripheral cities in Israel. Numeric simulations are carried out to test the research hypotheses regarding positive relationship between improved accessibility and enhanced economic welfare. Economic welfare is measured in terms of efficiency and equity impacts. The results of the simulations show that transportation improvements in the form of auto travel time reductions may lead to substantial welfare benefits in the peripheral region considered in terms of increased output, productivity and wages

A color duplex-doppler ultrasonographic study of the hepatic neoplasic vascularization

A diferenciacao das lesoes hepaticas focais vem se constituindo num dos maiores desafios da ultra-sonografia diagnostica e dos outros metodos por imagem, dada a elevada frequencia em que ocorrem e a superposicao de suas caracteristicas morfologicas, o que dificulta sua distincao. A incorporacao do sistema Doppler-duplex colorido aos modernos equipamentos de ultrasonografia abriu um novo horizonte no arsenal diagnostico que visa aumentar a acuracia na caracterizacao dessas lesoes. Em nosso estudo, utilizando a ultrasonografia Doppler-duplex colorida, procuramos determinar criterios quantitativos (analise espectral) e qualitativos (Doppler colorido) para o diagnostico diferencial das principais lesoes hepaticas focais, confirmadas histologicamente. Foram avaliados 41 pacientes sendo 11 deles portadores de hepatocarcinomas, 22 de metastases de origens diversas e oito de hemangiomas hepaticos. A frequencia de pico sistolico medio de hepatocarcinomas (3,96 KHz) mostrou-se superior a de metastases (l,78 KHz) e hemangiomas (O,83 KHz) de forma estatisticamente significante. O indice de resistividade de Pourcelot medio de hepatocarcinomas (O,78) mostrou-se superior em relacao ao de hemangiomas hepaticos (O,55). O indice de pulsatilidade mostrou ser parametro sem valor estatistico para a diferenciacao das lesoes. Na analise qualitativa do padrao de vascularizacao, obsermos uma maior tendencia de os hepatocarcinomas em apresentar o padrao de rede vascular periferica, comparativamente as metastases e hemangiomas. Concluimos ser a frequencia de pico sistolico um parametro util de auxilio na diferenciacao dos tres tipos histologicos de lesoes focais. O indice de resistividade mostrou ser parametro util de auxilio na distincao entre hepatocarcinomas e hemangiomasBV UNIFESP: Teses e dissertaçõe

Equity Impacts of Transportation Improvements On Core and Peripheral Cities

The aim of this paper is to assess the short-term impact of transportation improvements on the reduction of socioeconomic disparities between core and peripheral cities. Data used in the analysis was extracted from the 1995 Israel Census. The methodology applied in the study was to estimate discrete choice models in an attempt to identify key variables affecting commuting decisions. Policy simulations are employed to illustrate the effect of diminishing spatial friction on wage convergence between poor southern towns and affluent core cities. The empirical evidence suggests that transportation improvements, especially in the form of introducing new rail links in underserved cities, could significantly contribute to the alleviation of spatial wage disparities between core and peripheral cities

Equity Impacts of Transportation Improvements On Core and Peripheral Cities

The aim of this paper is to assess the short-term impact of transportation improvements on the reduction of socio-economic disparities between core and peripheral cities. Data used in the analysis was extracted from the 1995 Israel Census. The methodology applied in the study was to estimate discrete choice models in an attempt to identify key variables affecting commuting decisions. Policy simulations are employed to illustrate the effect of diminishing spatial friction on wage convergence between poor southern towns and affluent core cities. The empirical evidence suggests that transportation improvements, especially in the form of introducing new rail links in underserved cities, could significantly contribute to the alleviation of spatial wage disparities between core and peripheral cities.transportation improvements; economic equity; wage disparities; discrete choice

Is liver perfusion CT reproducible? A study on intra-and interobserver agreement of normal hepatic haemodynamic parameters obtained with two different software packages

Objective: To evaluate the agreement between the measurements of perfusion CT parameters in normal livers by using two different software packages. Methods: This retrospective study was based on 78 liver perfusion CT examinations acquired for detecting suspected liver metastasis. Patients with any morphological or functional hepatic abnormalities were excluded. The final analysis included 37 patients (59.7 +/- 14.9 y). Two readers (1 and 2) independently measured perfusion parameters using different software packages from two major manufacturers (A and B). Arterial perfusion (AP) and portal perfusion (PP) were determined using the dual-input vascular one-compartmental model. Inter-reader agreement for each package and intrareader agreement between both packages were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. Results: Inter-reader agreement was substantial for AP using software A (ICC = 0.82) and B (ICC = 0.85-0.86), fair for PP using software A (ICC = 0.44) and fair to moderate for PP using software B (ICC = 0.56-0.77). Intrareader agreement between software A and B ranged from slight to moderate (ICC = 0.32-0.62) for readers 1 and 2 considering the AP parameters, and from fair to moderate (ICC = 0.40-0.69) for readers 1 and 2 considering the PP parameters. Conclusion: At best there was only moderate agreement between both software packages, resulting in some uncertainty and suboptimal reproducibility. Advances in knowledge: Software-dependent factors may contribute to variance in perfusion measurements, demanding further technical improvements. AP measurements seem to be the most reproducible parameter to be adopted when evaluating liver perfusion CT.Univ Fed Sao Paulo, Dept Imaging, Sao Paulo, BrazilGrp Fleury, Dept Radiol, Sao Paulo, BrazilHosp Beneficencia Portuguesa, Dept Imaging, Sao Paulo, BrazilUniv Hosp Pisa, Dept Diagnost & Intervent Radiol, Pisa, ItalyUniv Fed Sao Paulo, Dept Imaging, Sao Paulo, BrazilWeb of Scienc