Ultrastructural Alterations in Lepocinclis acus (Euglenophyta) Induced by Medium with High Organic Matter Content

Ultrastructural changes induced by exposure to excess of organic matter were studied in Lepocinclis acus (ex Euglena acus). The cells isolated from the Matanza River, Buenos Aires, Argentina, were grown in soil water medium (SWM). When transferred to medium enriched with Bacteriological Peptone OXOID®, marked body deformation and a significant shortening and widening of the cells was observed. These changes were unexpected in a species with quite rigid cells, a condition previously shown in studies of the pellicle fine structure. Transmission electron microscopy observations suggest that cellular deformation might be facilitated by an increase in strip number, whereas in the original strips normal ultrastructure was maintained. An increase in number and volume of paramylon grains and vacuoles, as well as the presence of membrane whorls in vacuoles was observed. The fine structure of organisms grown in medium with and without organic matter enrichment was compared, and the systematic and ecological importance of morphological changes triggered by cell deformation was discussed.Fil: Conforti, Visitacion Teresa D.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Ruiz, Laura Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leonardi, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

Axonopathy in Huntington's disease.

Personality changes, psychiatric disturbances and cognitive abnormalities frequently characterise the prodromal phase in Huntington's disease (HD), a devastating monogenic neurodegenerative disorder manifesting with abnormal motor movements and early death. Selective loss of medium-sized spiny striatal neurons has been related to the onset of motor symptoms but it does not completely explain the psychiatric and cognitive changes that often precede motor abnormalities. Here we review the evidence of synaptic and axonal dysfunction and neurite dystrophy preceding neuronal loss in HD patients and models. We discuss possible mechanisms leading to dysfunction of the axonal and synaptic compartments and identify potential novel targets for effective therapeutic intervention

Adaptation to G93A superoxide dismutase 1 in a motor neuron cell line model of amyotrophic lateral sclerosis. The role of glutathione

Motor neuron degeneration in amyotrophic lateral sclerosis involves oxidative damage. Glutathione (GSH) is critical as an antioxidant and a redox modulator. We used a motor neuronal cell line (NSC-34) to investigate whether wild-type and familial amyotrophic lateral sclerosis-linked G93A mutant Cu,Zn superoxide dismutase (wt ⁄G93ASOD1) modified the GSH pool and glutamate cysteine ligase (GCL), the rate-limiting enzyme for GSH synthesis. We studied the effect of various G93ASOD1 levels and exposure times. Mutant Cu,Zn superoxide dismutase induced an adaptive process involving the upregulation of GSH synthesis, even at very low expression levels. However, cells with a high level of G93ASOD1 cultured for 10 weeks showed GSH depletion and a decrease in expression of the modulatory subunit of GCL. These cells also had lower levels of GSH and GCL activity was not induced after treatment with the pro-oxidant tertbutylhydroquinone. Cells with a low level of G93ASOD1 maintained higher GSH levels and GCL activity, showing that the exposure time and the level of the mutant protein modulate GSH synthesis. We conclude that failure of the regulation of the GSH pathway caused by G93ASOD1 may contribute to motor neuron vulnerability and we identify this pathway as a target for therapeutic intervention

Panel M.T.C. Experimentación sobre un sistema constructivo para viviendas rurales en Boyacá, Colombia

Este artículo enseña el proceso de investigación y realización del “Panel M.T.C.” como técnica constructiva para viviendas en zonas rurales de Boyacá (Colombia). La edificación de viviendas en este contexto es algo delicado ya que se trata de zonas alejadas y caracterizadas por una gran pobreza. Actualmente se ha perdido el uso de las técnicas constructivas tradicionales, adoptando soluciones “modernas” inadecuadas al contexto y costosas (materiales convencionales). La  propuesta del Panel M.T.C. se fundamenta en la reinterpretación del bahareque[1] y permite usar recursos locales (madera, tierra cruda, caña brava) y conocimientos ancestrales relacionados al contexto rural boyacense. El proyecto se articuló en dos fases, una de estudio del contexto socio-cultural y otra de investigación sobre las técnicas constructivas. Por ello se organizó en Ráquira (Boyacá) un taller con artesanos y algunas entrevistas a los habitantes. De tal manera se desarrolló un panel, cuya modularidad permite la parcial prefabricación y su conclusión a través de procesos de autoconstrucción. La solución permite desarrollar viviendas sostenibles de un piso, respondiendo a las necesidades ambientales, a la población y en acuerdo con el contexto geográfico y cultural. Sin embargo este proyecto abre un camino para profundizar en contextos y situaciones análogas.   [1] Bahareque: sistema de construcción típico de la tradición arquitectónica rural colombiana. Está hecho por una estructura en madera o caña y relleno de barro (Minke, 2010)

Membraneless flow battery leveraging flow-through heterogeneous porous media for improved power density and reduced crossover

We propose and demonstrate a novel flow battery architecture that replaces traditional ion-exchange membranes with less expensive heterogeneous flow-through porous media. Compared to previous membraneless systems, our prototype exhibits significantly improved power density (0.925 W cm[superscript -2]), maximum current density (3 A cm[suprescript -2]), and reactant crossover, shown by the proposed experimentally-validated crossover model

Microfluidic Platforms for Evaluation of Nanobiomaterials: a Review

L

Microfluidic Platforms for Evaluation of Nanobiomaterials: A Review

Biomaterials, especially those based on nanomaterials, have emerged as critical tools in biomedical applications. The applications encompass a wide range such as implantable devices, tissue regeneration, drug delivery, diagnostic systems, and molecular printing. The type of materials used also covers a wide range: metals (permanent and degradable), polymers (permanent and degradable), carbon nanotubes, and lipid nanoparticles. This paper explores the use of microfluidic platforms as a high-throughput research tool for the evaluation of nanobiomaterials. Typical screening of such materials involves cell/tissue cultures to determine attributes such as cell adhesion, proliferation, differentiation, as well as biocompatibility. In addition to this, other areas such as drug delivery and toxicity can also be evaluated via microfluidics. Traditional approach for screening of such materials is very time-consuming, and a lot of animals should be sacrificed since it involves one material and a single composition or concentration for a single test. The microfluidics approach has the advantage of using multiple types of drugs and their concentration gradients to simultaneously study the effect on the nanobiomaterial and its interaction with cell/tissue. In addition to this, microfluidics provides a unique environment to study the effect of cell-to-extracellular interaction and cell-to-cell communication in the presence of the nanobiomaterials

Novedades jurisprudenciales en materia ambiental

Ningun