Manipulation of salicylate content in Arabidopsis thaliana by the expression of an engineered bacterial salicylate synthase.

Salicylic acid (SA) plays a central role as a signalling molecule involved in plant defense against microbial attack. Genetic manipulation of SA biosynthesis may therefore help to generate plants that are more disease-resistant. By fusing the two bacterial genes pchA and pchB from Pseudomonas aeruginosa, which encode isochorismate synthase and isochorismate pyruvate-lyase, respectively, we have engineered a novel hybrid enzyme with salicylate synthase (SAS) activity. The pchB-A fusion was expressed in Arabidopsis thaliana under the control of the constitutive cauliflower mosaic virus (CaMV) 35S promoter, with targeting of the gene product either to the cytosol (c-SAS plants) or to the chloroplast (p-SAS plants). In p-SAS plants, the amount of free and conjugated SA was increased more than 20-fold above wild type (WT) level, indicating that SAS is functional in Arabidopsis. P-SAS plants showed a strongly dwarfed phenotype and produced very few seeds. Dwarfism could be caused by the high SA levels per se or, perhaps more likely, by a depletion of the chorismate or isochorismate pools of the chloroplast. Targeting of SAS to the cytosol caused a slight increase in free SA and a significant threefold increase in conjugated SA, probably reflecting limited chorismate availability in this compartment. Although this modest increase in total SA content did not strongly induce the resistance marker PR-1, it resulted nevertheless in enhanced disease resistance towards a virulent isolate of Peronospora parasitica. Increased resistance of c-SAS lines was paralleled with reduced seed production. Taken together, these results illustrate that SAS is a potent tool for the manipulation of SA levels in plants.

Environmental and genetic variation of isoflavone content of soybean seeds grown in Brazil

The objective of this work was to evaluate isoflavone concentrations in seeds of different Brazilian soybean cultivars grown in a range of locations and environmental conditions in Brazil. Seeds of 233 cultivars grown in Ponta Grossa, PR, Brazil, during the 2001/2002 soybean season, and of 22 cultivars sown in different locations of Brazilian Northeast, Southeast on South regions were analyzed for total isoflavones, including daidzin, glycitin, genistin and acetylgenistin. The total isoflavones ranged from 12 mg 100 g-1 (cv. Embrapa 48) to 461 mg 100 g-1 (cv. CS 305) among the 233 cultivars grown in Ponta Grossa, and the differences among them are due to genetic effects since all cultivars were grown and collected at the same locatation and year. This is an indication of the possibility of breeding for isoflavone content. Differences in isoflavone content observed in the cultivars grown in different locations permit the selection of locations for optimum isoflavone content (low or high), depending on the uses of soybean. In the Northeast region (5-8°S), higher concentrations of total isoflavones were observed at São Raimundo das Mangabeiras (232 mg 100 g-1) and Tasso Fragoso (284 mg 100 g-1) municipalities, and in the South (23-30°S), isoflavones were higher in Guarapuava, Canoinhas, Vacaria and Campos Novos municipalities, ranging from 130 to 409 mg 100 g-1.

On the diurnal soil water content dynamics during evaporation using dielectric methods

The water content dynamics in the upper soil surface during evaporation is a key element in land-atmosphere exchanges. Previous experimental studies have suggested that the soil water content increases at the depth of 5 to 15 cm below the soil surface during evapo- ration, while the layer in the immediate vicinity of the soil surface is drying. In this study, the dynamics of water content profiles exposed to solar radiative forcing was monitored at a high temporal resolution using dielectric methods both in the presence and absence of evaporation. A 4-d comparison of reported moisture content in coarse sand in covered and uncovered buckets using a commercial dielectric-based probe (70 MHz ECH2O-5TE, Decagon Devices, Pullman, WA) and the standard 1-GHz time domain reflectometry method. Both sensors reported a positive correlation between temperature and water content in the 5- to 10-cm depth, most pronounced in the morning during heating and in the afternoon during cooling. Such positive correlation might have a physical origin induced by evaporation at the surface and redistribution due to liquid water fluxes resulting from the temperature- gradient dynamics within the sand profile at those depths. Our experimental data suggest that the combined effect of surface evaporation and temperature-gradient dynamics should be considered to analyze experimental soil water profiles. Additional effects related to the frequency of operation and to protocols for temperature compensation of the dielectric sensors may also affect the probes' response during large temperature changes.

Genetic control of potassium content of common bean seeds

The objective of this work was to investigate possible maternal effects on potassium content of common bean seeds, as well as to estimate the heritability and selection gains in early hybrid generations for this character and to evaluate the efficiency of genetic selection to improve the nutritional quality of common bean (Phaseolus vulgaris). Crosses with four cultivars from the Mesoamerican gene pool yielded the reciprocal F1 and F2 generations and the backcrossed populations (BCP1 and BCP2). The potassium content of the progenies was measured via nitric‑perchloric digestion and flame photometry. The potassium content in the tested progenies varied from 6.0 to 14.9 g kg-1 dry matter, and no significant maternal effect was observed. The narrow-sense heritability ranged from low (33.26%) to intermediate (43.05%). Partial dominance was observed for low potassium content in the seeds. No increase in potassium content was obtained through selection. Breeding common bean plants for increasing potassium content in seeds may be difficult because the local environment strongly influences the character.

Variability of ricin content in mature seeds of castor bean

The objective of this work was to evaluate ricin concentration in castor bean seeds (Ricinus communis) of 20 accessions from the Banco de Germoplasma de Mamoneira of the Embrapa Algodão, Campina Grande, PB, Brazil, using the Enzyme Linked Immunosorbent Assay. Significant differences were observed among accessions. BRA 3271 had the highest ricin concentration in seeds (32.18 ng µg-1), and BRS Paraguaçu had the lowest (3.53 ng µg-1). There is the possibility of selecting genotypes with different ricin concentrations, which can be used according on the interest of the breeding programs.

The Relationship of Aggregate Durability to Trace Element Content, Interim Report, HR-266, 1984

This report is a brief overview of the recent Iowa Department of Transportation research in the area of durability of Portland cement, concrete under the direction of Wendeli Dubberke. Present plans are to publish a more detailed report on low Portland cement concrete- durability research in January, 1985.

Improving breast cancer education: the case of an evolving multidisciplinary module for undergraduate medical students (lausanne medical school, 1993-2008).

Breast cancer is a public health issue in numerous countries. Multidisciplinary collaboration is required for patient care, research, and also education of future physicians. This paper uses Kern's framework for curriculum design to demonstrate how a breast diseases module for undergraduate medical students created in 1993 evolved over 15 years. The main outcomes of program refinements were better integrated course content, the development of electronic course documents, and implementation of computer-aided small group learning. A main future challenge is to further develop efficient instructional strategies in line with well-defined learning needs for undergraduate students.

How to redesign a virtual library website: a case study

This abstract presents how we redesigned, with user-centred design methods, the way we organize and present the content on the UOC Virtual Library website. The content is now offered in a way that is more intuitive, usable and easy to understand, based on criteria of customization, transparency and proximity.The techniques used to achieve these objectives included benchmarking, interviews and focus groups during the user requirement capture phase and user tests to assess the process and results.

Storage protein profile and amino acid content in wild rice Oryza glumaepatula

- The objective of this work was to determine the total protein profile and the contents of the four major protein fractions (albumin, globulin, prolamin and glutelin) and of the amino acids in the endosperm of the rice wild species Oryza glumaepatula. The experiment was performed with 29 accessions of this species, collected from 13 Brazilian locations, and two commercial cultivars. Protein samples were prepared using dried, polished, and ground grains to obtain homogeneous, dry flour used in the preparation of extracts. Oryza glumaepatula accessions were identified with the highest levels of total protein, albumin and glutelin protein fractions, and amino acids (with the exception of tryptophan) in comparison to the two analized rice cultivars. The albumin and glutelin profiles in SDS-Page were distinct between rice cultivars and O. glumaepatula. This wild species has the potential to increase the nutritional quality of rice storage protein through interspecific crosses.

La Gestión de la Información Personal en usuarios intensivos de las TIC

Se presenta un modelo de análisis del comportamiento informacional global de un colectivo de individuos (estudiantes de la Universitat Oberta de Catalunya) que tienen una percepción positiva sobre el uso de las tecnologías de la información y la comunicación y que realizan un uso intensivo de las mismas.A partir de una aproximación cualitativa, mediante 24 entrevistas y un posterior análisis del contenido, se identifican cuatro perfiles distintos de gestión de la información personal (reactivo, pasivo, exhaustivo y proactivo) en base a diez variables subyacentes (acceso, gestión y usos de la información, competenciasinformacionales, perfil cognitivo, actitud, percepción de las TIC, ámbito académico, profesional y de la vida diaria) y se ponen derelieve las diferencias de comportamiento informacional dependiendo del ámbito en el que se encuentren. La identificación de los perfiles es un estadio básico del diseño centrado en los usuarios que facilita la realización de intervenciones específicas para cada tipo de usuario, respetando requerimientos de herramientasy procesos para que puedan desarrollar su comportamiento informacional de forma eficiente y eficaz.

Improving Searching and Browsing Capabilities of Learning Object Repositories

Learning object repositories are a basic piece of virtual learning environments used for content management. Nevertheless, learning objects have special characteristics that make traditional solutions for content management ine ective. In particular, browsing and searching for learning objects cannot be based on the typical authoritative meta-data used for describing content, such as author, title or publicationdate, among others. We propose to build a social layer on top of a learning object repository, providing nal users with additional services fordescribing, rating and curating learning objects from a teaching perspective. All these interactions among users, services and resources can be captured and further analyzed, so both browsing and searching can be personalized according to user pro le and the educational context, helping users to nd the most valuable resources for their learning process. In this paper we propose to use reputation schemes and collaborative filtering techniques for improving the user interface of a DSpace based learning object repository.

Gestió dels recursos docents en el marc de l'EEES

L'Espai Europeu d'Educació Superior comporta un canvi de paradigma molt important, com ésl'adopció d'un procés d'aprenentatge basat en l'adquisició i desenvolupament de competències mitjançant activitats, relegant els continguts a un segon terme. El propi concepte d'activitat inclou i combina elements molt diversos que involucren recursos docents de tota mena, tot abastant un ventall més ampli del que s'entén estrictament per contingut en el sentit tradicional. És necessari, doncs, plantejar-se una gestió dels recursos docents orientada a facilitar la creació d'itineraris formatius que permetin als estudiants assolir les competències desitjades, així com complementar la seva formació. En lloc de proporcionar els continguts directament als estudiants, l'objectiu és aconseguir un procés d'aprenentatge centrat en l'usuari mitjançant la formació que els permeti ser autònoms en la localització, l'ús i fins i tot la generació de continguts necessaris en cada activitat.

OpenApp: experiencias y herramientas docentes y de gestión en abierto

La Universitat Oberta de Catalunya (UOC) es una universidad en línea que realiza un uso intensivo de las tecnologías de la información y la comunicación para proporcionar una educación y aprendizaje a lo largo de la vida. Des de sus inicios la universidad ha desarrollado y testeado metodologías y tecnologías con el objetivo de proporcionar soluciones a los retos de aprendizaje y docentes ofrecidos por la comunidad de estudiantes, académicos y personal de gestión.Fundamentado en este saber hacer, nace la plataforma OpenApps con la finalidad principal de poner a disposición de la comunidad la experiencia acumulada en la UOC durante más de 15 años en docencia, aprendizaje y gestión para que pueda ser aplicado, adaptado o evolucionado por terceros. En este artículo se presentan las características esenciales para que una innovación pueda formar parte de esta plataforma institucional, las especificaciones y usuarios de la plataforma, la finalidad del servicio y las futuras líneas de trabajo.