AN ANALYSIS OF A UNITED STATES-CANADA-MEXICO FREE TRADE AGREEMENT

This is one of two papers commissioned by the International Agricultural Trade Research Consortium on various aspects related to the agricultural sector of a prospective North American Free Trade Agreement. The companion paper to this one has been prepared by a working group chaired by Richard Barichello, University of British Columbia. To minimize duplication with the Barichello paper this paper has given greater attention to the role of Mexico, currency exchange rates, and explicit modeling of the trade relationship.International Relations/Trade,

Water partitioning and respiration activity of dormant grape buds

Dormancy of 'Pinot Noir' grapevines was characterized. Primary buds required ca 300 cumulative chilling hours (CCH) to initiate the transition from endodormancy to ecodormancy, which occurred in mid November. Additional chilling, up to 1000 CCH, improved budbreak. Changes in bud water content were estimated by gravimetric and spectroscopic methods. Total, intra-, and extracellular water were measured gravimetrically. The total water and the intracellular fraction increased during the ecodormant period. A method to evaluate bud water status by proton-nuclear magnetic resonance was developed. Grape buds present anisotropic behavior. Using this method, water content was partitioned into free and bound fractions. Free water was always larger than bound water. Furthermore, bound water reached its peak in January when ecodormant plants were exposed to colder temperatures. These results support former evidence that bound water is composed of one population with restricted mobility, and another in a transient state. Respiration pattern of overwintering buds was investigated using differential scanning calorimetry. Endodormant buds decreased their respiration. In February, an increase in respiration, typical of the period preceding budbreak, was observed in ecodormant buds. Ecodormant and breaking buds were classified into four developmental stages. Those stages were: ecodormant, initial swelling, fully swollen, and broken buds. Isothermal experiments at 25°C were done to evaluate metabolic heat rate, CO₂ evolution rate, and metabolic efficiency. Also, buds were scanned from 1 to 60°C (7°C/hr) to estimate activation energy and Q₁₀ values. Metabolic heat rates were 5, 17, 28, and 29 μW/mg dw, respectively, for the four bud developmental stages listed above. In the same order, CO₂ evolution increased from 2 to 3, 6, and 7 /μW/mg dw. The efficiency of metabolism, however, decreased during the initial swelling stage. High apparent activation energy values for ecodormant and initial swelling buds showed that metabolism at those stages is slow, mostly because it is energetically expensive. As the buds developed, activation energy decreased, indicating a more favorable condition from a thermodynamic standpoint. Q₁₀ values demonstrated that grapevines are highly responsive to temperature. Water content and respiration activity are useful indicators of metabolic activity

Freeze Damage of Pinot noir (Vitis vinifera L.) as Affected by Bud Development, INA Bacteria, and a Bacterial Inhibitor

Spring freeze decreased the yield of field grown grapevines by 70%. The spring bud development of Pinot noir was characterized into seven stages after the initial budbreak, 96% of the buds attained full development in 44 days. Controlled freezing tests were used to determine bud hardiness. The T50 values (temperature when 50% of buds are damaged) for quiescent, swollen, bud urst, first, second, and third flat leaf bud stages were -14, -3, -2.2, -2, -1.7, and 1.1oC, respectively. The water content increased from 57 to 84% frorn the quiescent to the swollen bud stage, thereafter little change occurred. A high correlation was found between hardiness, water content, and stage of bud development. Genotype and culture age affected the ice nucleation activity of three Pseudomonas syringae strains (P. syringae is common bacteria found on grapevines). The cells attained stationary phase of growth after 60 hr. in culture. The INA (ice nucleation activity) of PssB15 occurred in the range of -2 to-4oC throughout the 7 days of evaluation. Pss2-3RNH INA was prevalent in 3-day-old cultures only. Pss2-3 was a poor ice nucleator. The INA of bacterial suspensions was directly proportional to concentrations ranging from 109 to 102 cells/ ml, which nucleated ice from -2.5 to -15.1oC. INA-bacteria at 108cells/ml incited freeze injury to grape leaf tissue specifically from -2 to -4oC. Frost Gard, a commercial chemical promoted as a freeze protectant, did not show antifreeze action (in water solutions) at concentrations of 0, 0.12, 0.25, 0.50, and 1%. At these concentrations, the water solutions froze at -11.6, -12.0, -11.8, -11.7, and -12.5oC, respectively, suggesting that the water ice nucleation temperature depended on the amount of impurities in the solutions. Frost Gard at 0.25, 0.50, and 1% had a strong bactericide effect on a bacterial suspension of 8 X 109 cells/ml. The same concentrations also lowered the nucleation temperature to -4.5, -6.9, and -5.2oC compared to the control suspension at -2.5oC. It was concluded that Frost Gard binds with the active site of nucleation since it strongly interacted with an inorganic ice nucleator. Frost Gard at 0.25% applied to grape leaf disks reduced the damaged area by 7% only at -2oC. Phytotoxicity due to Frost Gard was observed at rates above .25%. Grape cuttings were used to test the capacity of an antibiotic resistant strain of Pseudomonas syringaeto Page 1 of 2Grape Research Reports, 1988: Freeze Damage of Pinot noir translocate through the vascular tissue. The cuttings were placed in bacterial suspensions of ca. 102, 104, and 106 cells/ml for 24, 36, and 48 hr. Bacterial populations recovered were inversely proportional to the length of the cutting section regardless of the time of exposure to the inoculum. It was determined that the liquids moved faster through the vascular tissue than the bacteria

Adsorption of Toxic Metal Ions From Solution by Inactivated Cells of Larrea Tridentata Creosote Bush

Larrea tridentata (creosote bush) is a plant that grows abundantly in the desert environment. This desert plant has been found naturally growing in heavy-metal contaminated soils. Previous experiments showed that the inactivated biomass of creosote bush was able to adsorb Cu(II) ions from aqueous solutions. The copper-binding capacity of the bush biomass that grows in heavy-metal uncontaminated soils was higher than the biomass that grows in heavy-metal contaminated soils. Experiments were performed to determine the ability of creosote bush biomass (grown in heavy metal uncontaminated soils) to adsorb Pb(II), Cd(II), Zn(II), Cr(III), Cr(VI), and Ni(II) ions from aqueous solutions. Batch pH profile experiments for these metal ions showed that the metal ion binding was different for every metal tested but increased as the pH was raised from 2.0 to 6.0. The metal ion uptake by the roots, stems, and leaves was quite fast. Binding capacity experiments showed a more significant binding capacity for lead(II) and chromium(III) ions and in general, the leaves bound more metal ions than the stems and roots. A great portion of the metal ions adsorbed by the creosote’s roots, stems, and leaves was desorbed by treatment with 0.1 M HCl (up to 99% in some cases). Biomass of creosote bush may prove to be useful to remove and recover metal ions from contaminated waters

Bacanora and Sotol: So Far, So Close

El propósito de este trabajo es familiarizar al lector con algunos aspectos relacionados, no sólo con dos bebidas alcohólicas de profundo arraigo en la cultura rural del México norteño, sino también con Agave angustifolia, conocido en Sonora como “agave (o mezcal) bacanora”; y un grupo de especies del género Dasylirion, conocido en México como “sotoles”, y “desert spoon” o ¨cuchara del desierto¨ en los Estados Unidos de América. Ambas comparten múltiples características morfológicas, fisiológicas y ecológicas que les permiten vivir en ambientes áridos. De igual forma, también intenta señalar aspectos únicos de las dos denominaciones de origen que protegen la elaboración de esas bebidas y que han surgido en los albores de este siglo, así como a las normas que rigen su elaboración

HRTEM characterization of gold nanoparticles produced by wheat biomass

In this study, the bio-reduction of Au(III) to Au(0) by wheat biomass and the subsequent production of gold nanoparticles of various shapes and sizes is presented. The dry biomass was ground and sieved in order to assure a uniform particle size and having more area of biomass exposed to the gold. Wheat biomass was exposed to a 0.3mM potassium tetrachloroaurate solution at pH values of 2, 3, 4, 5, and 6 for three and a half hours at room temperature. After that time, the biomass pellets were analyzed using a high resolution transmission electron microscope, JEOL-4000 EX, in order to characterize the gold nanoparticles. The results showed that wheat biomass produced nanostructures of the following morphologies: Fcc tetrahedral (T), decahedral (Dh), hexagonal (He), icosahedral multitwinned (I), irregular shape (Irr), and rod shape nanoparticles. The highest percent of the nanoparticles formed had a particle size ranging from 10-30 nm.Fil: Armendáriz, V.. University of Texas at El Paso; Estados UnidosFil: José Yacamán, Miguel. University of Texas at Austin; Estados UnidosFil: Duarte Moller, A.. University of Texas at El Paso; Estados Unidos. Centro de Investigación en Materiales Avanzados; MéxicoFil: Peralta Videa, J. R.. University of Texas at El Paso; Estados UnidosFil: Troiani, Horacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. University of Texas at Austin; Estados UnidosFil: Herrera, I.. University of Texas at El Paso; Estados UnidosFil: Gardea Torres, J. L.. University of Texas at El Paso; Estados Unido

Illness trajectory from prodromal symptoms to incident bipolar disorder and schizophrenia

Background: The concept of prodrome is highly variable but, when applied retrospectively in cohorts who progress to meet diagnostic criteria for bipolar disorder (BD) and schizophrenia (SZ), it can contribute to clarify early origins and trajectory of the illness. In the context of race and ethnicity, studies with population-based and registry-based cohorts, such as the Rochester Epidemiology Project (REP), can potentially identify, through retrospective assessment of the prodromes of BD and SZ, differences while addressing the heterogeneous nature of the illness. Objective: We aim to describe and compare the illness trajectories of individuals with BD or SZ prior to the incident case. Additionally, we assessed for differences in access to healthcare in racially diverse patients and within those with schizophrenia, we sought to analyze differences in prodrome duration based on place of birth (U.S. born vs. foreign born). Methods: Using a records-linkage system from Minnesota, we searched for subjects born after 1985 that had been diagnosed with BD or SZ. Cases were ascertained for diagnosis and identification of the first episode of mania or psychosis. Using the medical records we extracted data from their medical history prior to their first episode. Results: We identified 205 cases with the first episode of psychosis or mania (SZ = 131; BD = 74). The mean age of onset for BD was 21.34 years and 20.45 years for SZ. We did not find a difference between the mean duration of the trajectory of mental health problems to a first episode. Both disorders were preceded by high healthcare utilization and had similar rates of psychiatric diagnoses, substance use, and prescriptions of psychiatric medications. SZ was more common in Non-white patients and in immigrants and BD had a higher rate of depressive disorder and adjustment disorders. Conclusions: Results from this study provide critical information on social and clinical features that precede a first manic or psychotic episode that may help early illness detection, identification of individuals at high risk of BD and SZ and address health disparities

Proximal chemical analysis and secondary metabolites in Washingtonia robusta fruit (Arecaceae): relevance for the feeding of wildlife and human

Background: Washingtonia robusta fruits are a staple for birds, small and medium-size mammals, and humans. However, quantitative data of their nutritional contribution has remained unknown. This is the first report on the phytochemical components found in fruit pulp and seeds. Questions: Does pulp compounds favor its consumption and contribute with nutrients for wildlife and humans? Do seed contents favor ecological interactions for germination and plantlet development? Species study: Washingtonia robusta H. Wendl. Study site and dates: Sierra El Aguaje, Sonora, Mexico, February - April 2016 Methods: Chemical and secondary metabolite analyses were carried out from extracts via phytochemical coloring tests and ultra-resolution liquid chromatography. Antioxidant activity was analyzed by DPPH. Results: Washingtonia robusta seeds contain 73 % sugars, 7.4 % protein, 8.4 % humidity, 4.3 % ashes, 8.7 % fat and 0.2 % calcium, while cyanogenic glycosides content was 0.8 mu g/g. Pulp has 71 % sugars, 10.8 % protein, 1.6 % humidity, 5.5 % ashes, 9.4 % fat and 1.5 % calcium, and cyanogenic glycosides reached 0.2 mu g/g. Alkaloids, tannins, saponins, phenols, and flavonoids were more abundant in seeds than in pulp. The DPPH assay expressed in Trolox equivalents indicated antioxidant capacity. Conclusions: Washingtonia robusta pulp is an important source of sugars and natural antioxidants for wildlife and human consumption. Occurrence of secondary metabolites prevents pathogens in seeds, also they could be beneficial for germination and initial plantlet development.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]