Matching form with content

Successful computer-supported distance education requires that its enabling technologies are accessible and usable anywhere. They should work seamlessly inside and outside the information superhighway, wherever the target learners are located, without obtruding on the learning activity. It has long been recognised that the usability of interactive computer systems is inversely related to the visibility of the implementing technologies. Reducing the visibility of technology is especially challenging in the area of online language learning systems, which require high levels of interactivity and communication along multiple dimensions such as speaking, listening, reading and writing. In this article, the authors review the concept of invisibility as it applies to the design of interactive technologies and appliances. They describe a specialised appliance matched to the requirements for distance second language learning, and report on a successful multi-phase evaluation process, including initial field testing at a Thai open university.

Matching form with content

Successful computer-supported distance education requires that its enabling technologies are accessible and usable anywhere. They should work seamlessly inside and outside the information superhighway, wherever the target learners are located, without obtruding on the learning activity. It has long been recognised that the usability of interactive computer systems is inversely related to the visibility of the implementing technologies. Reducing the visibility of technology is especially challenging in the area of online language learning systems, which require high levels of interactivity and communication along multiple dimensions such as speaking, listening, reading and writing. In this article, the authors review the concept of invisibility as it applies to the design of interactive technologies and appliances. They describe a specialised appliance matched to the requirements for distance second language learning, and report on a successful multi-phase evaluation process, including initial field testing at a Thai open university.

Heart failure gene therapy: the path to clinical practice

Gene therapy, aimed at the correction of key pathologies being out of reach for conventional drugs, bears the potential to alter the treatment of cardiovascular diseases radically and thereby of heart failure. Heart failure gene therapy refers to a therapeutic system of targeted drug delivery to the heart that uses formulations of DNA and RNA, whose products determine the therapeutic classification through their biological actions. Among resident cardiac cells, cardiomyocytes have been the therapeutic target of numerous attempts to regenerate systolic and diastolic performance, to reverse remodeling and restore electric stability and metabolism. Although the concept to intervene directly within the genetic and molecular foundation of cardiac cells is simple and elegant, the path to clinical reality has been arduous because of the challenge on delivery technologies and vectors, expression regulation, and complex mechanisms of action of therapeutic gene products. Nonetheless, since the first demonstration of in vivo gene transfer into myocardium, there have been a series of advancements that have driven the evolution of heart failure gene therapy from an experimental tool to the threshold of becoming a viable clinical option. The objective of this review is to discuss the current state of the art in the field and point out inevitable innovations on which the future evolution of heart failure gene therapy into an effective and safe clinical treatment relies.

Successful surgical resection in non-lesional operculo-insular epilepsy without intracranial monitoring

Pre-operative assessment and surgical management of patients with non-lesional extratemporal epilepsy remain challenging due to a lack of precise localisation of the epileptic zone. In most cases, invasive recording with depth or subdural electrodes is required. Here, we describe the case of 6.5-year-old girl who underwent comprehensive non-invasive phase I video-EEG investigation for drug-resistant epilepsy, including electric source and nuclear imaging. Left operculo-insular epilepsy was diagnosed. Post-operatively, she developed aphasia which resolved within one year, corroborating the notion of enhanced language plasticity in children. The patient remained seizure-free for more than three years.

Molecular mechanism by which the Escherichia coli nucleoid occlusion factor, SlmA, keeps cytokinesis in check

Cell division or cytokinesis is one of the most fundamental processes in biology and is essential for the propagation of all living species. In Escherichia coli, cell division occurs by ingrowth of the membrane envelope at the cell center and is orchestrated by the FtsZ protein. FtsZ self-assembles into linear protofilaments in a GTP dependent manner to form a cytoskeletal scaffold called the Z-ring. The Z-ring provides the framework for the assembly of the division apparatus and determines the site of cytokinesis. The total amount of FtsZ molecules in a cell significantly exceeds the concentration required for Z-ring formation. Hence, Z-ring formation must be highly regulated, both temporally and spatially. In particular, the assembly of Z-rings at the cell poles and over chromosomal DNA must be prevented. These inhibitory roles are played by two key regulatory systems called the Min and nucleoid occlusion (NO) systems. In E. coli, Min proteins oscillate from pole to pole; the net result of this oscillatory process is the formation of a zone of FtsZ inhibition at the cell poles. However, the replicated nucleoid DNA near the midcell must also be protected from bisection by the Z-ring which is ensured by NO. A protein called SlmA was shown to be the effector of NO in E. coli. SlmA was identified in a screen designed to isolate mutations that were lethal in the absence of Min, hence the name SlmA (synthetic lethal with a defective Min system). Furthers SlmA was shown to bind DNA and localize to the nucleoid fraction of the cell. Additionally, light scattering experiments suggested that SlmA interacts with FtsZ-GTP and alters its polymerization properties. Here we describe studies that reveal the molecular mechanism by which SlmA mediates NO in E. coli. Specifically, we determined the crystal structure of SlmA, identified its DNA binding site specificity, and mapped its binding sites on the E. coli chromosome by chromatin immuno-precipitation experiments. We went on to determine the SlmA-FtsZ structure by small angle X-ray scattering and examined the effect of SlmA-DNA on FtsZ polymerization by electron microscopy. Our combined data show how SlmA is able to disrupt Z-ring formation through its interaction with FtsZ in a specific temporal and spatial manner and hence prevent nucleoid guillotining during cell division.

Measuring the gravitational free-fall of antihydrogen

Antihydrogen holds the promise to test, for the first time, the universality of freefall with a system composed entirely of antiparticles. The AEgIS experiment at CERN’s antiproton decelerator aims to measure the gravitational interaction between matter and antimatter by measuring the deflection of a beam of antihydrogen in the Earths gravitational field (g). The principle of the experiment is as follows: cold antihydrogen atoms are synthesized in a Penning-Malberg trap and are Stark accelerated towards a moir´e deflectometer, the classical counterpart of an atom interferometer, and annihilate on a position sensitive detector. Crucial to the success of the experiment is the spatial precision of the position sensitive detector.We propose a novel free-fall detector based on a hybrid of two technologies: emulsion detectors, which have an intrinsic spatial resolution of 50 nm but no temporal information, and a silicon strip / scintillating fiber tracker to provide timing and positional information. In 2012 we tested emulsion films in vacuum with antiprotons from CERN’s antiproton decelerator. The annihilation vertices could be observed directly on the emulsion surface using the microscope facility available at the University of Bern. The annihilation vertices were successfully reconstructed with a resolution of 1–2 μmon the impact parameter. If such a precision can be realized in the final detector, Monte Carlo simulations suggest of order 500 antihydrogen annihilations will be sufficient to determine gwith a 1 % accuracy. This paper presents current research towards the development of this technology for use in the AEgIS apparatus and prospects for the realization of the final detector.

Ion channel macromolecular complexes in cardiomyocytes: roles in sudden cardiac death.

The movement of ions across specific channels embedded on the membrane of individual cardiomyocytes is crucial for the generation and propagation of the cardiac electric impulse. Emerging evidence over the past 20 years strongly suggests that the normal electric function of the heart is the result of dynamic interactions of membrane ion channels working in an orchestrated fashion as part of complex molecular networks. Such networks work together with exquisite temporal precision to generate each action potential and contraction. Macromolecular complexes play crucial roles in transcription, translation, oligomerization, trafficking, membrane retention, glycosylation, post-translational modification, turnover, function, and degradation of all cardiac ion channels known to date. In addition, the accurate timing of each cardiac beat and contraction demands, a comparable precision on the assembly and organizations of sodium, calcium, and potassium channel complexes within specific subcellular microdomains, where physical proximity allows for prompt and efficient interaction. This review article, part of the Compendium on Sudden Cardiac Death, discusses the major issues related to the role of ion channel macromolecular assemblies in normal cardiac electric function and the mechanisms of arrhythmias leading to sudden cardiac death. It provides an idea of how these issues are being addressed in the laboratory and in the clinic, which important questions remain unanswered, and what future research will be needed to improve knowledge and advance therapy.

AN INVESTIGATION OF VOLATILE ORGANIC AIR CONTAMINANTS IN THE INDOOR MANUFACTURED HOUSING ENVIRONMENT (TEXAS)

Manufactured housing has been found to have substantial levels of formaldehyde in the indoor air. Because mobile homes are more affordable than conventional housing, there has been a large increase in their use in the U.S. This increase in mobile home use has been substantial in the sunbelt regions such as Texas, where high temperatures and humidities may enhance out-gassing of formaldehyde and other volatile organic compounds from construction and furnishing materials and increase any potential health hazards.^ The influences of environmental, architectural and temporal factors on the presence of indoor formaldehyde and other organic compounds were investigated in conjunction with the Texas Indoor Air Quality Study of manufactured housing. A matched pair of mobile homes, one with electric heating and cooking utilities and the other with propane gas utilities, were used for a series of controlled experiments over a fourteen month period from October, 1982 through November, 1983.^ Over this fourteen month period formaldehyde levels decreased approximately 33%. Daily fluctuations of 20% to 40% were observed even with a constant indoor temperature. An increase in indoor temperature of 8(DEGREES)C doubled the measured formaldehyde concentration. Opening windows resulted in decreases of indoor formaldehyde levels of up to 50%. Studies of the impact of propane as a cooking source showed no increase in formaldehyde levels with stove use.^ The presence and concentration of selected volatile organic compounds is influenced greatest by occupancy. Occupants continually open and close windows and doors, vary the operation and settings (temperature) of air control systems, and vary in their selection of furnishings and use of consumer products, which may act as sources of indoor air contaminants. ^

Method of threshing grain

This invention relates generally to grain threshing apparatus and in particular to an improved method of an apparatus for threshing grain wherein an impeller is rotatable within a concave or tubular screen. An object of this invention is to provide an improved method and apparatus for threshing grain.

Proceedings of the Twenty-Sixth Annual Biochemical Engineering Symposium

This volume contains the Proceedings of the Twenty-Sixth Annual Biochemical Engineering Symposium held at Kansas State University on September 21, 1996. The program included 10 oral presentations and 14 posters. Some of the papers describe the progress of ongoing projects, and others contain the results of completed projects. Only brief summaries are given of some of the papers; many of the papers will be published in full elsewhere. A listing of those who attended is given below. ContentsForeign Protein Production from SV40 Early Promoter in Continuous Cultures of Recombinant CHO Cells - Gautam Banik, Paul Todd, and Dhinakar Kampala Enhanced Cell Recruitment Due to Cell-Cell Interactions - Brad Farlow and Matthias Nollert The Recirculation of Hybridoma Suspension Cultures: Effects on Cell Death, Metabolism and Mab Productivity - Peng Jin and Carole A. Heath The Importance of Enzyme Inactivation and Self-Recovery in Cometabolic Biodegradation of Chlorinated Solvents - Xi-Hui Zhang, Shanka Banerji, and Rakesh Bajpai Phytoremediation of VOC contaminated Groundwater using Poplar Trees - Melissa Miller, Jason Dana, L.C. Davis, Murlidharan Narayanan, and L.E. Erickson Biological Treatment of Off-Gases from Aluminum Can Production: Experimental Results and Mathematical Modeling - Adeyma Y. Arroyo, Julio Zimbron, and Kenneth F. Reardon Inertial Migration Based Separation of Chlorella Microalgae in Branched Tubes - N.M. Poflee, A.L. Rakow, D.S. Dandy, M.L. Chappell, and M.N. Pons Contribution of Electrochemical Charge to Protein Partitioning in Aqueous Two-Phase Systems - Weiyu Fan and Charles C. Glatz Biodegradation of Some Commercial Surfactants Used in Bioremediation - Jun Gu, G.W. Preckshot, S.K. Banerji, and Rakesh Bajpai Modeling the Role of Biomass in Heavy Metal Transport Ln Vadose Zone - K.V. Nedunuri, L.E. Erickson, and R.S. Govindaraju Multivariable Statistical Methods for Monitoring Process Quality: Application to Bioinsecticide Production by 73 89 Bacillus Thuringiensis - c. Puente and M.N. Karim The Use of Polymeric Flocculants in Bacterial Lysate Streams - H. Graham, A.S. Cibulskas and E.H. Dunlop Effect of Water Content on transport of Trichloroethylene in a Chamber with Alfalfa Plants - Muralidharan Narayanan, Jiang Hu, Lawrence C. Davis, and Larry E. Erickson Detection of Specific Microorganisms using the Arbitrary Primed PCR in the Bacterial Community of Vegetated Soil - X. Wu and L.C. Davis Flux Enhancement Using Backpulsing - V.T. Kuberkar and R.H. Davis Chromatographic Purification of Oligonucleotides: Comparison with Electrophoresis - Stephen P. Cape, Ching-Yuan Lee, Kevin Petrini, Sean Foree, Micheal G. Sportiello and Paul Todd Determining Singular Arc Control Policies for Bioreactor Systems Using a Modified Iterative Dynamic Programming Algorithm - Arun Tholudur and W. Fred Ramirez Pressure Effect on Subtilisins Measured via FTIR, EPR and Activity Assays, and Its Impact on Crystallizations - J.N. Webb, R.Y. Waghmare, M.G. Bindewald, T.W. Randolph, J.F. Carpenter, C.E. Glatz Intercellular Calcium Changes in Endothelial Cells Exposed to Flow - Laura Worthen and Matthias Nollert Application of Liquid-Liquid Extraction in Propionic Acid Fermentation - Zhong Gu, Bonita A. Glatz, and Charles E. Glatz Purification of Recombinant T4 Lysozyme from E. Coli: Ion-Exchange Chromatography - Weiyu Fan, Matt L. Thatcher, and Charles E. Glatz Recovery and Purification of Recombinant Beta-Glucuronidase from Transgenic Corn - Ann R. Kusnadi, Roque Evangelista, Zivko L. Nikolov, and John Howard Effects of Auxins and cytokinins on Formation of Catharanthus Roseus G. Don Multiple Shoots - Ying-Jin Yuan, Yu-Min Yang, Tsung-Ting Hu, and Jiang Hu Fate and Effect of Trichloroethylene as Nonaqueous Phase Liquid in Chambers with Alfalfa - Qizhi Zhang, Brent Goplen, Sara Vanderhoof, Lawrence c. Davis, and Larry E. Erickson Oxygen Transport and Mixing Considerations for Microcarrier Culture of Mammalian Cells in an Airlift Reactor - Sridhar Sunderam, Frederick R. Souder, and Marylee Southard Effects of Cyclic Shear Stress on Mammalian Cells under Laminar Flow Conditions: Apparatus and Methods - M.L. Rigney, M.H. Liew, and M.Z. Southard

La actividad hidrocarburífera en la Cuenca del Golfo San Jorge : El papel del empresariado regional

La política económica que se implementó en la década de 1990 tuvo como eje, entre las principales medidas, la apertura de la economía, la privatización de las empresas públicas, el desmantelamiento del aparato estatal y sus agentes reguladores, el ajuste fiscal y del gasto público tanto a nivel nacional, como provincial y municipal, la retirada del Estado Nacional como inversor y subsidiador de actividades económicas, la desregulación del mercado de trabajo y la concentración en grupos 'oligopólicos' de las principales actividades productivas, lo que produjo diferentes impactos en las distintas actividades económicas de la Región Patagónica, dependiendo de su inserción en el mercado interno y externo. En este trabajo se pretende, a partir de una descripción de la evolución de la actividad petrolera y de un estudio de caso, analizar los factores que viabilizan el desarrollo económico local y repensar el papel de los actores sociales en relación con el contexto y con las posibilidades de establecimiento de estrategias de innovación en las sociedades locales. En la primera parte del artículo se hace una caracterización socioeconómica de la región de la Cuenca del Golfo San Jorge. A continuación se observa la evolución de la actividad petrolera dentro de la cuenca, su papel en el mercado de trabajo y su requerimiento de mano de obra; se realiza una caracterización de los principales actores y de su relación con el desarrollo local. En la parte final del artículo se intenta mostrar los desafíos que enfrentan los actores públicos y privados vinculados con la actividad petrolera y su proyección en el corto y mediano plazo

Estado, cooperativismo eléctrico y electrificación rural. La experiencia cordobesa entre 1930 y 1980

Pese a que el movimiento cooperativo eléctrico de Córdoba es uno de los más importantes del país y en la actualidad mueve gran parte de la economía del interior provincial, su surgimiento y desarrollo es una cuestión que aún no ha sido suficientemente tratada por la historiografía local. De allí la decisión de abordar tal temática que en este artículo se analiza desde la perspectiva de las relaciones entre el desarrollo del cooperativismo eléctrico y la expansión de la intervención del Estado en el sector eléctrico, pero prestando especial atención a los avances de la electrificación en el sector rural. Ese análisis abarca un amplio periodo de medio siglo, entre la aparición de las primeras cooperativas eléctricas y el momento en que, desde el punto de vista eléctrico, la provincia mediterránea deja de constituir un sistema independiente y se incorpora al sistema interconectado nacional, y muestra el papel jugado por esas entidades en el proceso de electrificación del campo que es un capítulo importante en el desarrollo eléctrico argentino y en el que las cooperativas eléctricas fueron precursoras, mucho antes de que el tema preocupase a los poderes públicos y cuando la política de las empresas privadas, atenidas a la rentabilidad, no planificó ni un metro de línea rural. Las cooperativas, en cambio, demostraron ser capaces de hacer electrificación rural con eficiencia.

La Cooperativa de Luz y Fuerza de Río Tercero: una institución al servicio de su comunidad, 1933- 1953

En nuestro país, las cooperativas eléctricas surgieron a partir de la década de 1920 como reacción popular frente a las elevadas tarifas y al deficiente servicio proporcionado por las empresas de capital extranjero que tenían a su cargo la generación y la distribución de energía. La provincia de Córdoba no fue ajena a este fenómeno, en este artículo nos proponemos mostrar las circunstancias en que surgió la Cooperativa de Luz y Fuerza de Río Tercero en 1933, la que a diferencia de otras de la provincia de Córdoba no generaba la energía que distribuía sino que la compraba a la usina hidráulica del dique Río Tercero, y al mismo tiempo resaltar también su evolución y las repercusiones de su gestión durante las dos primeras décadas de vida en las que prestó el servicio de energía eléctrica y comenzó con las gestiones encaminadas a concretar la provisión de agua corriente a la población de Río Tercero, convirtiéndose en la Cooperativa de Luz y Fuerza y Agua Potable de Río Tercero Limitada inaugurando ese servicio en 1953.

Estado provincial y municipios bonaerenses, una relación conflictiva en los años del primer peronismo

Este trabajo tiene como objetivo analizar la relación que mantuvo el estado provincial con los municipios bonaerenses durante los años del primer peronismo, que presentó como rasgo particular un progresivo intervencionismo del gobierno provincial sobre las administraciones comunales. Esta tendencia colaboró en la formación de un modelo estadual centralizado que se caracterizó, entre otros aspectos, por limitar la autonomía de los gobiernos comunales. Asimismo esta modalidad fue acompañada por una creciente desvalorización del rol político de los intendentes, en beneficio de otras esferas del aparato estatal como del propio partido, y por su reconversión en simples funcionarios administrativos.

La actividad hidrocarburífera en la Cuenca del Golfo San Jorge : El papel del empresariado regional

La política económica que se implementó en la década de 1990 tuvo como eje, entre las principales medidas, la apertura de la economía, la privatización de las empresas públicas, el desmantelamiento del aparato estatal y sus agentes reguladores, el ajuste fiscal y del gasto público tanto a nivel nacional, como provincial y municipal, la retirada del Estado Nacional como inversor y subsidiador de actividades económicas, la desregulación del mercado de trabajo y la concentración en grupos 'oligopólicos' de las principales actividades productivas, lo que produjo diferentes impactos en las distintas actividades económicas de la Región Patagónica, dependiendo de su inserción en el mercado interno y externo. En este trabajo se pretende, a partir de una descripción de la evolución de la actividad petrolera y de un estudio de caso, analizar los factores que viabilizan el desarrollo económico local y repensar el papel de los actores sociales en relación con el contexto y con las posibilidades de establecimiento de estrategias de innovación en las sociedades locales. En la primera parte del artículo se hace una caracterización socioeconómica de la región de la Cuenca del Golfo San Jorge. A continuación se observa la evolución de la actividad petrolera dentro de la cuenca, su papel en el mercado de trabajo y su requerimiento de mano de obra; se realiza una caracterización de los principales actores y de su relación con el desarrollo local. En la parte final del artículo se intenta mostrar los desafíos que enfrentan los actores públicos y privados vinculados con la actividad petrolera y su proyección en el corto y mediano plazo