Efecto de materiales inertes de formulas bioinsecticidas en la proteccion de tuberculos almacenados contra las polillas de papa.

En las zonas productoras de papa (Solanum tuberosum Linneo) del Perú, dos especies de polilla de la papa están presentes: Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae) y Symmetrischema tangolias Gyen (Gelechiidae). Para contrarrestar sus efectos dañinos, los productores de papa espolvorean sus tubérculos almacenados con materiales inertes o fórmulas en talco a base del granulovirus que ataca a P. operculella (PoGV). El objetivo de esta investigación fue determinar el efecto protector de materiales inertes (talco, caolín, cal y arena), aplicados a tubérculos de papa, contra larvas de ambas especies y definir la dosis óptima de aplicación. Los tubérculos de papa (cv. “Peruanita”) impregnados con estos materiales a una dosis de 5 g/kg de papa (experimento 1) y diferentes dosis: 0,625; 1,25; 2,5; 5; 10 y 15 g/kg de papa (experimento 2) se inocularon por separado con larvas neonatales de ambas especies e incubaron a 25°C (P. operculella) y 20°C (S. tangolias). La comparación de potencias obtenidas por regresión Probit demostraron que el talco ejerce significativamente mayor actividad letal sobre ambas especies y que S. tangolias es más susceptible que P. operculella. Incrementos en la dosis de talco, caolín, y cal elevan los índices de mortalidad con pendientes paralelas entre si en ambas especies, sin embargo, aun con la máxima dosis aplicable de talco (15 g/kg) no se protegen por completo los tubérculos. Una dosis de talco de 5 g/kg de papa (equivalente a las aplicaciones con fórmula de PoGV en talco), produce mortalidades de 47% (P. operculella) y 66% (S. tangolias), pudiendo incrementarse a 6 g/kg de papa. Ambas resultan óptimas según los niveles de control esperados, sus costos y la actividad del patógeno en caso de fórmulas

Climate change and crop diversity: farmers’ perceptions and adaptation on the Bolivian Altiplano

Crop diversity is central to traditional risk management practices on the Andean Altiplano and may find renewed importance in adapting to climate change. This study explored the role of crop diversity in farmers’ adaptation actions in eight Aymara communities on the northern Bolivian Altiplano. Using a combination of quantitative and qualitative methods, including multifactor analysis and a community resilience self-assessment, we investigated how farmers’ use of diversity in adaptation is related to their perceptions of crop and variety tolerances and other environmental, social, and economic factors. Few crops and varieties were perceived as tolerant to increasingly intense and unpredictable drought, frost, hail, and pest and disease outbreaks. Some local crops and varieties were perceived as vulnerable to emerging conditions (e.g. oca, papalisa, isaño), whereas bitter potatoes and wild relatives of quinoa and cañahua were perceived as highly stress tolerant and provide food in harsh periods. A total 19% of households surveyed (N = 193) had introduced new crops or varieties—often disease resistant or early maturing—as an adaptive action. Introduction of commercial crops was a common adaptation action, reflecting farmers’ response to warming temperatures and changing economic opportunities, but greater sensitivity of the introduced crops may cause maladaptation. Despite intensification of cropping systems, households continue to maintain a median four potato varieties with different tolerance traits, yet this risk management practice was not perceived as adaptation. Strengthening resilience will require a combination of actions, including maintaining and expanding crop portfolios and restoring soil and ecosystem health, using both traditional and innovative approaches

CARACTERIZACIÓN MOLECULAR DE Azospirillum sp., Azotobacter sp. Y Pseudomonas sp. PROMOTORAS DEL CRECIMIENTO VEGETAL DE CULTIVOS DE Solanum tuberosum y Zea mays

Con el objetivo de generar un banco autóctono con bacterias promotoras del crecimiento vegetal (PGPR) y su posterior utilización como inoculantes del suelo que disminuyan la fertilización química, se tomaron muestras de raíces de cultivos de papa (Solanum tuberosum Var Canchan) y de maíz (Zea mayz Var Blanco mejorado) tratados con cinco tipos de abonamiento: estiércol de ovino, cuy y vacuno, fertilización química y sin fertilizante, de las cuales se aislaron cepas de bacterias nitrificantes correspondientes a los géneros Azospirillum, Azotobacter y Pseudomonas. Las bacterias fueron diferenciadas en base a su morfología, poder generador de auxinas, solubilización de fosfatos, reacción a la catalasa, oxidasa y similaridad genética previa amplificación de la región del mRNA 16S. Los resultados muestran una amplia base genética que necesita ser caracterizada e identificada exhaustivamente. La producción de AIA en Azospirillum llegó hasta niveles de 120 ppm; 118 ppm para el género Azotobacter y 115 ppm en Pseudomonas fluorescens. De cepas seleccionadas, el DNA fue secuenciado, comparado con la Base de Datos del GenBank  e identificadas hasta especie, tales como Azospirillum brasilense; Azotobacter vinelandii,  A. choccrococum, A. nigricans y A. salinestris. Las secuencias amplificadas con los primer universales 9-27F y 1542R para las cepas de Azospirillum, Azotobacter y Pseudomonas fluorescens utilizados para este estudio no están reportados en la base de datos del GenBank. Palabras clave: Bacterias promotoras del crecimiento vegetal (PGPR), Azospirillum sp, Azotobacter sp, Pseudomonas fluorescens, Acido Indol Acético, Solubilización de fosfatos.ABSTRACTWith the aim of generating a native bank with Promoting Grow Plant Rhizobacteria (PGPR) and their later use as inoculates of the soils that diminishes the chemical fertilization, samples were taken from roots of cultures of potato (Solanum tuberosum Var Canchan) and of maize (Zea mayz Var Improved white) dealt with five types of fertilization: ovine, bovine guinea and pig manure, chemical fertilization and without fertilizer, of which strains of nitrogen-fixing bacteria corresponding to the genera Azospirillum, Azotobacter and Pseudomonas were isolated. The bacteria were differentiated on the basis of their morphology, generating power of auxins, phosphate solubilization, reaction to the catalase, oxidasa and genetic similarity previous amplification of the region of rRNA 16S. The results show an ample genetic base that exhaustive need to be characterized and to be identified. The production of AIA in Azospirillum arrived until 120 levels of ppm; 118 ppm for the genera Azotobacter and 115 ppm in Pseudomonas fluorecens. Of selected strains, the DNA was sequenced, compared with Base of Data the GenBank and identified until species, such as Azospirillum brasilense; Azotobacter vinelandii, A. choccrococum, A. nigricans and A. salinestris. The sequences amplified with primer universal 9-27F and 1542R for the strains of Azospirillum, Azotobacter and Pseudomonas fluorescens used for this study are not reported in the data base of the GenBank.Key words: Promoting Grow Plant Rhizobacteria (PGPR), Azospirillum sp., Azotobacter sp., Pseudomonas fluorescens, Acetic Indol Acid, phosphate solubilization.

Niveles de hemoglobina de lactantes de 0 a 6 meses de edad hospitalizados en el Instituto Nacional de Salud del Niño, 2015

Introduction. In Peru, we have few studies related to anemia that covers the first year of life. There are aspects in the way of establishing the diagnoses, treatments and interventions at the population level, which require specialized approaches and approaches that help to improve this public health problem. Objective. To determine the hemoglobin levels of infants 0 to 6 months of age hospitalized in the medicine services of the Instituto Nacional del Niño in 2015. Methods. 80 medical records of hospitalized patients were reviewed. The infants whose cause of hospitalization was not related to comorbidities and who lived at sea level were identified. Results 55% of infants presented anemia. The main reason for hospitalization was bronchiolitis (36.3%) followed by pneumonia (20%). Conclusion. 55% of infants from 0 to 6 months hospitalized presented anemia in our investigation.Introducción. En el Perú, contamos con pocos estudios relacionados con anemia que abarque el primer año de vida. Existen aspectos en la forma de establecer los diagnósticos, tratamientos e intervenciones a nivel poblacional, que requieren planteamientos y enfoques especializados que ayuden a mejorar este problema de salud pública. Objetivo. Determinar los niveles de hemoglobina de lactantes de 0 a 6 meses de edad hospitalizados en los servicios de medicina del Instituto Nacional de Salud del Niño en el año 2015. Métodos. Se revisaron 80 historias clínicas de pacientes hospitalizados. Se identificó a los lactantes cuya causa de hospitalización no estuviera relacionada a comorbilidades y que vivieran a nivel del mar. Resultados. El 55% de lactantes presentó anemia. El principal motivo de hospitalización fue bronquiolitis (36,3%) seguida de neumonía (20%). Conclusión. El 55% de lactantes de 0 a 6 meses hospitalizados presentaró anemia en nuestra investigación

Assessment of SNPs for linkage mapping in Eucalyptus: construction of a consensus SNP/microsatellite map from two unrelated pedigrees

Financial support. Brazilian Ministry of Science and Technology (CNPq Grant 577047-2008-6), FAP-DF NEXTREE Grant 193.000.570/2009 and EMBRAPA Macroprogram 2 project grant 02.07.01.004

Synthesis and characterization of a-Fe2O3 nanoparticles showing potential applications for sensing quaternary ammonium vapor at room temperature

P-Type and n-Type metal oxide semiconductors are widely used in the manufacture of gas sensing materials, due to their excellent electronic, electrical and electrocatalytic properties. Hematite (?-Fe2O3) compound has been reported as a promising material for sensing broad types of gases, due to its affordability, good stability and semiconducting properties. In the present work, the efficient and easy-To-implement sol-gel method has been used to synthesize ?-Fe2O3 nanoparticles (NPs). The TGA-DSC characterizations of the precursor gel provided information about the phase transformation temperature and the mass percentage of the hematite NPs. X-ray diffraction, transmission electron microscopy and x-ray photoelectron spectroscopy data analyses indicated the formation of two iron oxide phases (hematite and magnetite) when the NPs are subjected to thermal treatment at 400 °C. Meanwhile, only the hematite phase was determined for thermal annealing above 500 °C up to 800 °C. Besides, the crystallite size shows an increasing trend with the thermal annealing and no defined morphology. A clear reduction of surface defects, associated with oxygen vacancies was also evidenced when the annealing temperature was increased, resulting in changes on the electrical properties of hematite NPs. Resistive gas-sensing tests were carried out using hematite NPs + glycerin paste, to detect quaternary ammonium compounds. Room-Temperature high sensitivity values (S r ?4) have been obtained during the detection of 1/41 mM quaternary ammonium compounds vapor. The dependence of the sensitivity on the particle size, the mass ratio of NPs with respect to the organic ligand, changes in the dielectric properties, and the electrical conduction mechanism of gas sensing was discussed

Ferromagnetic resonance for the quantification of superparamagnetic iron oxide nanoparticles in biological materials

The aim of the present work is the presentation of a quantification methodology for the control of the amount of superparamagnetic iron oxide nanoparticles (SPIONs) administered in biological materials by means of the ferromagnetic resonance technique (FMR) applied to studies both in vivo and in vitro. The in vivo study consisted in the analysis of the elimination and biodistribution kinetics of SPIONs after intravenous administration in Wistar rats. The results were corroborated by X-ray fluorescence. For the in vitro study, a quantitative analysis of the concentration of SPIONs bound to the specific AC133 monoclonal antibodies was carried out in order to detect the expression of the antigenic epitopes (CD133) in stem cells from human umbilical cord blood. In both studies FMR has proven to be an efficient technique for the SPIONs quantification per volume unit (in vivo) or per labeled cell (in vitro)

The Influence of Strata on the Nutrient Recycling within a Tropical Certified Organic Coffee Production System

In tropical Bolivia coffee plantations, the plant community can be separated into high (trees), middle (coffee), and low (weed) strata. Understanding the importance of each stratum is critical for improving the sustainability of the system. The objective of this study was to determine the importance of strata on nutrient recycling. Litter falls from the upper and middle strata were collected monthly using cone-shaped traps and divided by species into leaves, branches, flowers, and fruits. Dry biomass additions to the soil from high and middle strata totaled 12,655 kg (ha yr)−1 annually. About 76% of the biomass was provided by plants of the genus Inga (I. adenophylla and I. oerstediana). The middle stratum (Coffea arabica L.) provided 24% litterfall biomass. This stratum also produced 1,800 kg coffee bean per ha (12% moisture) which sold for $2.94 kg−1. In the lower stratum, Oxalis mollissima returned 36 kg N ha−1, while Solanum nodiflorum returned 49 kg K ha−1, and Urticasp. returned 18 kg Ca ha−1. The nutrients recycled through plants in three strata exceeded the amount of nutrients removed in green coffee beans