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

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 logi

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

Interobserver agreement on non-contrast computed tomography interpretation for diagnosis of urolithiasis in patients with acute flank pain

OBJECTIVE: To evaluate the interobserver agreement on non-contrast computed tomography interpretation by a group of experienced abdominal radiologists, for the study of urolithiasis in patients presenting acute flank pain. MATERIALS AND METHODS: Prospective study of 52 patients submitted to non-contrast enhanced helical computed tomography. The images were subsequently analyzed by three independent observers, with the interobserver agreement assessed by means of the kappa (kappa) statistical method. The following parameters were analyzed: a) presence, localization and measurement of ureteral calculi; b) intrarenal calyceal system dilatation; c) perirenal fat heterogeneity; d) ureteral dilatation; e) ureteral wall edema (halo sign). RESULTS: Ureteral calculi were found in 40 of 52 patients (77%). The interobserver agreement was almost perfect as regards identification of ureteral calculi (kappa = 0.89) and ureteral dilatation (kappa = 0.87), substantial for calyceal system dilatation (kappa = 0.77), and moderate for perirenal fat heterogeneity (kappa = 0.55) and ureteral wall edema (kappa = 0.56). CONCLUSION: Non-contrast-enhanced abdominal computed tomography presents high reproducibility in the evaluation of urolithiasis and secondary signs of the calyceal system obstruction.OBJETIVO: Avaliar a reprodutibilidade da tomografia computadorizada sem contraste na avaliação da litíase ureteral e os sinais secundários de obstrução do sistema coletor em pacientes com cólica renal aguda. MATERIAIS E MÉTODOS: Estudo prospectivo de 52 pacientes com diagnóstico clínico de cólica renal aguda submetidos a exame de tomografia computadorizada de abdome sem contraste. Os exames foram realizados com técnica helicoidal e posteriormente analisados por três observadores independentes, com a concordância interobservador avaliada pelo método estatístico kappa (kapa). Foram analisados os parâmetros: a) presença, localização e mensuração dos cálculos ureterais; b) dilatação do sistema coletor intra-renal; c) heterogeneidade da gordura perirrenal; d) dilatação ureteral; e) edema da parede ureteral (sinal do halo). RESULTADOS: Foram encontrados 40 cálculos ureterais na tomografia computadorizada (77%). A concordância interobservador para a identificação do cálculo ureteral e da dilatação ureteral foi quase perfeita (kapa = 0,89 e kapa = 0,87, respectivamente), substancial para dilatação do sistema coletor intra-renal (kapa = 0,77) e moderada para heterogeneidade da gordura perirrenal e para edema da parede ureteral (kapa = 0,55 e kapa = 0,56, respectivamente). CONCLUSÃO: A tomografia computadorizada de abdome sem contraste apresenta elevada reprodutibilidade na avaliação da litíase ureteral e dos sinais secundários de obstrução do sistema coletor.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Diagnóstico por ImagemColégio Brasileiro de Radiologia e Diagnóstico por ImagemUNIFESP, EPM, Depto. de Diagnóstico por ImagemSciEL

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

Glucose absorption by the interposed colon segment after extensive intestinal resection

One of the proposed surgical treatments of Short Bowel Syndrome is the interposition of a distal colon segment between two portions of the remnant small intestine. This method proved to reverse the nutritional disorders caused by this morbid entity. Surgical technique consisted in an 80 % small bowel resection and the interposition of a 3 cm segment of distal colon between the remaining jejunum and ileum. After 70 days, the animals were reoperated and the interposed and the distal colon were isolated and tied. By using the method of rapid and successive absorptions of a glucose solution through the intestinal lumen, the relations between the absorption curves of the interposed and the normal colon could be dran. Results show that the interposed colon segment absorbs more glucose (mean = 1.43 +/- 1.16 mg/dl) than the distal colon (mean = 0.37 +/- 0.29 mg/dl) and that its absorption pattern is similar to the small bowel rather than the colon. These results allow the use of this method for further studies in which the interposed colon adaptation is studied with other nutrients and/or under specific conditions.ESCOLA PAULISTA MED SCH,POSTGRAD COURSE SURG TECH & EXPTL SURG,RUA BOTUCATU 720,VILA CLEMENTINO,BR-04023 SAO PAULO,BRAZILESCOLA PAULISTA MED SCH,POSTGRAD COURSE SURG TECH & EXPTL SURG,RUA BOTUCATU 720,VILA CLEMENTINO,BR-04023 SAO PAULO,BRAZILWeb of Scienc