Sustainable management in pecan cultivation in Argentina

243-248Pecan nut "Carya illinoinensis" is native from central and western U.S.A. and arrived in Argentina in the nineteenth century. The difference with other nuts is that it presents an 80 percent oil composition, with polyunsaturated fatty acids omega 3 and 6 that help to reduce cholesterol and also prevent the risk of cardiovascular disease. It contains an antioxidant: vitamin E, and has a high content of fibre that helps to prevent colon cancer. Reduces bad cholesterol, helps keep blood pressure low and is recommended especially for patients with cancer and cardiac problems. A pecan sustainable farming system intends to be productive but at the same time, to preserve enviromental quality, favouring the use of biological practices over chemical inputs. Surface application of compost to pecan trees, is a common practice in organic orcharding. The objectives of the work were to compare compost and vermicompost with liquid fertilizer and a control without fertilization in a completely random block design with four replications, in a one-year crop with a planting frame of 8m x 8m. The application of organic amendments produced statistically significant changes in soil properties with reference to inorganic fertilizer, especially in the total carbon, microbial biomass carbon and phosphorus. Compost and vermicompost treatments produced statistically significant increases in factors related to production as tree height and diameter

La Ética Pública como Deber de Priorizar Las Razones Públicas: Una Solución A La Corrupción Por Vía Democrática

A partir del estudio del caso argentino, argumentamos que la noción de la ética pública predominante se centra en la corrupción, entendida como enriquecimiento de la persona que ejerce la función pública. Frente a esta noción limitada de la ética pública, proponemos entenderla como el deber de ejercer la función estatal conforme a razones públicas. De esta noción más amplia, derivamos tres propuestas para asegurar una función pública ética. Por un lado, una regulación abarcadora y precisa de los conflictos de intereses en el ejercicio de la función pública. Por otro lado, la implementación de mecanismos de participación social en la configuración y control de las decisiones públicas. Por último, nuestro proyecto exige una autoridad de aplicación independiente, autónoma y autárquica

Fertilización de base en un cultivo inicial de pecan con dos marcos de plantación de alta densidad

91-97The fruit of the pecan tree, Carya illinoensis Koch, is considered a very healthy food. In Argentina, pecan cultivation has been expanding rapidly but very little research has been conducted on pecan fertilization and planting systems. The objectives of this study were to characterize some physical-chemical and chemical properties in a pecan crop, and compare different basal fertilization (FB) treatments under two high density plantation frames (MP). Plantation was conducted in Villanueva (Buenos Aires province), on a Tapthoargic Hapludoll, with 10 x 10 m frames (real part: MR) and 8 x 8 m frames (staggered: TR). The experimental design was a split plot with four replications. The main plots were the two frames and the subplots were the different fertilization treatments: Compost (C), Phosphorus (P), slow release Nitrogen (N), and an unfertilized control (T). The determinations to assess the growth of pecan plants were: plant height and stem diameter. With regard to soil fertility, phosphorus fertilization and the addition of compost significatively increased the levels of Bray-P. The organic fertilizer treatment (compost) showed a significant increase in the height of the pecan plantation under the 8 x 8 m frame, which was not apparent in any case for the stem diameter, with a MP x FB significant interaction (P = 0.01) for height variation in the first year. The plantation frame with or without basal fertilization had no effect on pecan volume during the study period

Public health and heavy metals in urban and periurban horticulture

148-154The health effects of heavy metals can be complex and severe. Exposure to heavy metals has been linked with developmental retardation, various cancers, kidney damage, and even death in some instances of exposure to very high concentrations. Soils in urban and suburban areas are transformed by human activities, they are characterized by a strong spatial heterogeneity resulting from the various inputs of exogenous materials and the mixing of original soil material, and they often hold pollutants that may be a threat to human health. The objective of this work is to present a study of heavy metals occurrence in 33 urban and periurban soils dedicated to horticulture in Buenos Aires (Argentina). Total heavy metal content in soils (cadmium, chromium, copper, nickel, lead and zinc) was evaluated using Sequential Plasma Emission Spectrometer (ICP-ES). Data were analyzed using multivariate analysis showing a primary separation in two groups: eight sites with high contents of one or more of the analized heavy metals and the second group with lower levels of heavy metals. Maximum values of Cd, Pb, Zn and Cu in horticultural soils resulted problematic with reference to public health

The Elusive Third Subunit IIa of the Bacterial B-Type Oxidases: The Enzyme from the Hyperthermophile Aquifex aeolicus

The reduction of molecular oxygen to water is catalyzed by complicated membrane-bound metallo-enzymes containing variable numbers of subunits, called cytochrome c oxidases or quinol oxidases. We previously described the cytochrome c oxidase II from the hyperthermophilic bacterium Aquifex aeolicus as a ba3-type two-subunit (subunits I and II) enzyme and showed that it is included in a supercomplex involved in the sulfide-oxygen respiration pathway. It belongs to the B-family of the heme-copper oxidases, enzymes that are far less studied than the ones from family A. Here, we describe the presence in this enzyme of an additional transmembrane helix “subunit IIa”, which is composed of 41 amino acid residues with a measured molecular mass of 5105 Da. Moreover, we show that subunit II, as expected, is in fact longer than the originally annotated protein (from the genome) and contains a transmembrane domain. Using Aquifex aeolicus genomic sequence analyses, N-terminal sequencing, peptide mass fingerprinting and mass spectrometry analysis on entire subunits, we conclude that the B-type enzyme from this bacterium is a three-subunit complex. It is composed of subunit I (encoded by coxA2) of 59000 Da, subunit II (encoded by coxB2) of 16700 Da and subunit IIa which contain 12, 1 and 1 transmembrane helices respectively. A structural model indicates that the structural organization of the complex strongly resembles that of the ba3 cytochrome c oxidase from the bacterium Thermus thermophilus, the IIa helical subunit being structurally the lacking N-terminal transmembrane helix of subunit II present in the A-type oxidases. Analysis of the genomic context of genes encoding oxidases indicates that this third subunit is present in many of the bacterial oxidases from B-family, enzymes that have been described as two-subunit complexes

Il cuore freddo di Bologna. Appunti per una storia delle ghiacciaie bolognesi

"Il cuore freddo di Bologna", progetto che si occupa del censimento, dell'analisi e della valorizzazione, anche attraverso progetti di recupero e riuso, delle architetture destinate alla produzione, al deposito e alla vendita del ghiaccio a Bologna e provincia