Have Biotech Seeds Increased Maize Yields?

Corn yield is determined by soils, weather, seed used and other technology choices. Global population and per capita income growth trends as well as demand from the energy sector have placed great stress on cropland use. Global cropland acres and/or yield per acre will need to increase. Whether new seed technologies have enhanced corn yield is a controversial issue. We study U.S. county corn yields 1964-2008, controlling for location effects, fertilization technologies and weather. We find evidence that trend yield growth has been fastest in the Central Corn Belt, genetic modification technologies have increased trend yield, and this increase has been largest in the Central Corn Belt.Biotechnology, Corn Yield, Trend, Regional Effects, Weather, Fertilization., Crop Production/Industries, Industrial Organization, Research and Development/Tech Change/Emerging Technologies, L65, Q16,

Bound and unbound nuclear systems at the drip lines: A one-dimensional model

22 págs.; 13 figs.; 1 tab.; 1 app.We construct a one-dimensional toy model to describe the main features of Borromean nuclei at the continuum threshold. The model consists of a core and two valence neutrons, unbound in the mean potential, that are bound by a residual point contact density-dependent interaction. Different discretization procedures are used (harmonic oscillator and transformed harmonic oscillator bases, or use of large rigid wall box). Resulting energies and wave functions, as well as inelastic transition intensities, are compared within the different discretization techniques, as well as with the exact results in the case of one particle and with the results of the di-neutron cluster model in the two particles case. Despite its simplicity, this model includes the main physical features of the structure of Borromean nuclei in an intuitive and computationally affordable framework, and will be extended to direct reaction calculations. © 2016 IOP Publishing Ltd Printed in the UKPart of this work was funded by MINECO grant FIS2014-53448-C2-2-P. LM thanks the University of Huelva, where part of this work was done with the finantial support of the Erasmus Placement program.Peer Reviewe

In Search of Differential Inhibitors of Aldose Reductase

Aldose reductase, classified within the aldo-keto reductase family as AKR1B1, is an NADPH dependent enzyme that catalyzes the reduction of hydrophilic as well as hydrophobic aldehydes. AKR1B1 is the first enzyme of the so-called polyol pathway that allows the conversion of glucose into sorbitol, which in turn is oxidized to fructose by sorbitol dehydrogenase. The activation of the polyol pathway in hyperglycemic conditions is generally accepted as the event that is responsible for a series of long-term complications of diabetes such as retinopathy, cataract, nephropathy and neuropathy. The role of AKR1B1 in the onset of diabetic complications has made this enzyme the target for the development of molecules capable of inhibiting its activity. Virtually all synthesized compounds have so far failed as drugs for the treatment of diabetic complications. This failure may be partly due to the ability of AKR1B1 to reduce alkenals and alkanals, produced in oxidative stress conditions, thus acting as a detoxifying agent. In recent years we have proposed an alternative approach to the inhibition of AKR1B1, suggesting the possibility of a differential inhibition of the enzyme through molecules able to preferentially inhibit the reduction of either hydrophilic or hydrophobic substrates. The rationale and examples of this new generation of aldose reductase differential inhibitors (ARDIs) are presented

Raw and extruded pea (Pisum sativum) and lupin (Lupinus albus var. Multitalia) seeds as protein sources in weaned piglets' diets: effect on growth rate and blood parameters

The 42 days trial was carried out using 140 piglets weaned at 28 days of age. The piglets were allocated according to weight and sex to the 5 dietary treatments with 7 replicates for each treatments (4 pens x 4 castrated males and 3 pens x 4 females). The piglets were fed according to the following experimental design: 1) control diet (CTR) with soybean meal (SBM) 44% c.p. as protein source; 2) CRT diets with 200 g/kg of raw pea (Pisum sativum) (RP); 3) CTR diet with 200 g/kg extruded pea (EP); 4) CRT diet with 170 g/kg raw lupin (Lupinus albusvar. Multitalia) (RL); 5) CTR diet with 170 g/kg of extruded lupin (EL). During the trial, animals were weighed at 0 - 21 and 42 days from the start of the trial. Feed intake was monitored and feed conversion ratio was calculated for the periods 0-21 d and 22-42 d. At the end of the trial, blood samples were taken for 14 animals for each dietary treatment (2 animals per replicate) and analysed for total protein, urea and liver activity (ALT, AST and ALP parameters). Average daily weight gain and feed intake did not differ according to dietary treatments whereas during the total experimental period (0-42 d), feed conversion ratio was higher for EP vsCTR diet (2.35 vs2.09, respectively; P <0.05). The growth rate for diets with extruded protein sources compared with diets containing the raw ingredients did not differ. Feed conversion ratio for the RP was numerically high- er than for the EP (2.35 vs2.16 and 2.76 vs2.32, respectively during 22-42 d and 0-42 d periods). Blood parameters did not show significant difference among dietary treatments except for higher total protein for CTR diet vsRL diet, EL and RP (67.3 vs62.2, 62.8 and 63.6 g/l, respectively; P<0.05) and urea that resulted the highest with CTR diet vsRL and RL (4.7 vs3.7 and 3.8 mmol/l respectively; P<0.05)

Weather-based models for predicting grape powdery mildew (Uncinula necator (Schwein) Burrill) epidemics

El oídio de la vid (Vitis vinifera L.), causado por Uncinula necator (Schwein) Burrill, es una enfermedad fúngica relevante en viñedos de la provincia de Mendoza, ocasionando pérdidas de producción y degradación de la calidad del fruto cosechado. Durante seis campañas agrícolas (2001/02; 2002/03; 2005/06; 2007/08; 2008/09; 2009/10), en un parral del cultivar susceptible Chenín (EEA INTA Mendoza, Luján de Cuyo), se observó la evolución de la incidencia del oídio en racimos (como tasa de incremento epidémica diaria), desde floración hasta envero. A partir de registros térmico-hídricos horarios (monitoreados con sensores ubicados en la parte superior del canopeo) se calcularon variables meteorológicas en los 15 días previos a cada observación del progreso de la epidemia. Con variables que integran efectos de la temperatura, humedad del aire y frecuencia de precipitaciones ligeras sobre el incremento de la enfermedad en función del tiempo, se ajustaron modelos de regresión logística para estimar las probabilidades de ocurrencia de tasas epidémicas categorizadas (severa, moderada y nula), logrando una precisión de predicción máxima de 92,5% (modelo bivariado, N=40). Las predicciones del modelo univariado (seleccionado por &quot;Stepwise&quot;; precisión de predicción: 87,5%) se validaron satisfactoriamente con la curva epidémica observada en 2000/2001. Los valores estimados por estos modelos podrían complementar a las observaciones epidémicas y emitir alarmas regionales que sustenten la toma de decisión de control químico.Powdery mildew, caused by Uncinula necator (Schwein) Burrill is one of the most damaging disease affecting grapevines (Vitis vinifera L.) in Mendoza and worldwide, reducing yield and fruit quality. Throughout six growing seasons (2001/02; 2002/03; 2005/06; 2007/08; 2008/09; 2009/10), powdery mildew incidence values (expressed as daily epidemic increment rates) were observed in clusters from flowering to onset of ripening (change of color of the grape berries), in a grapevine planted with the susceptible Chenin cultivar at the EEA INTA Mendoza (Luján de Cuyo). From hourly values of thermal-moisture elements recorded by upper canopy sensors, meteorological variables were calculated in the 15 previous days of each epidemic observation. Using variables which integrate the effects of air temperature and humidity and frequency of light precipitations over the epidemic progress, logistic models were adjusted for estimating the probability of occurrrence of severe, moderate and nil epidemic increment rates, reaching maximum prediction accuracy of 92.5% (two variable models, N=40). Predicted values by the univariate model (selected by Stepwise procedure; prediction accuracy: 87.5%) were validated with the epidemic curve observed during 2000/2001 growing season. These model predictions could complement epidemic observations, giving regional scale to warning systems for improving the decision making process regarding disease chemical control.Fil: Oriolani, Enrique J. A.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Moschini, Ricardo C.. Instituto de Clima y Agua. CIRN. INTA Castelar.Fil: Salas, Sergio. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Martinez, Malvina I.. Instituto de Clima y Agua. CIRN. INTA Castelar.Fil: Banchero, Santiago. Instituto de Clima y Agua. CIRN. INTA Castelar

Strength of Protection for Geographical Indications: Promotion Incentives and Welfare Effects

We address the question of how the strength of protection for geographical indications (GIs) affects the GI industry\u27s promotion incentives, equilibrium market outcomes, and the distribution of welfare. Geographical indication producers engage in informative advertising by associating their true quality premium (relative to a substitute product) with a specific label emphasizing the GI\u27s geographic origin. The extent to which the names/words of the GI label can be used and/or imitated by competing products—which depends on the strength of GI protection—determines how informative the GI promotion messages can be. Consumers’ heterogeneous preferences (vis-à-vis the GI quality premium) are modeled in a vertically differentiated framework. Both the GI industry and the substitute product industry are assumed to be competitive (with free entry). The model is calibrated and solved for alternative parameter values. Results show that producers of the GI and of the lower-quality substitute good have divergent interests: GI producers are better off with full protection, whereas the substitute good\u27s producers prefer intermediate levels of protection (but they never prefer zero protection because they benefit indirectly if the GI producers’ incentives to promote are preserved). For consumers and aggregate welfare, the preferred level of protection depends on the model\u27s parameters, with an intermediate level of protection being optimal in many circumstances

Economic Perspectives on GMO Market Segregation

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