Mitochondrial Association of a Plus End–Directed Microtubule Motor Expressed during Mitosis in Drosophila

The kinesin superfamily is a large group of proteins (kinesin-like proteins [KLPs]) that share sequence similarity with the microtubule (MT) motor kinesin. Several members of this superfamily have been implicated in various stages of mitosis and meiosis. Here we report our studies on KLP67A of Drosophila. DNA sequence analysis of KLP67A predicts an MT motor protein with an amino-terminal motor domain. To prove this directly, KLP67A expressed in Escherichia coli was shown in an in vitro motility assay to move MTs in the plus direction. We also report expression analyses at both the mRNA and protein level, which implicate KLP67A in the localization of mitochondria in undifferentiated cell types. In situ hybridization studies of the KLP67A mRNA during embryogenesis and larval central nervous system development indicate a proliferation-specific expression pattern. Furthermore, when affinity-purified anti-KLP67A antisera are used to stain blastoderm embryos, mitochondria in the region of the spindle asters are labeled. These data suggest that KLP67A is a mitotic motor of Drosophila that may have the unique role of positioning mitochondria near the spindle

Laccase immobilization on enzymatically functionalized polyamide 6,6 fibres

Polyamide matrices, such as membranes, gels and non-wovens, have been applied as supports for enzyme immobilization, although in literature the enzyme immobilization on woven nylon matrices is rarely reported. In this work, a protocol for a Trametes hirsuta laccase immobilization using woven polyamide 6,6 (nylon) was developed. A 24 full factorial design was used to study the influence of pH, spacer (1,6-hexanediamine), enzyme and crosslinker concentration on the efficiency of immobilization. The factors enzyme dosage and spacer seem to have played a critical role in the immobilization of laccase onto nylon support. Under optimized working conditions (29 U mL−1 of laccase, 10% of glutaraldehyde, pH = 5.5, with the presence of the spacer), the half-life time attained was about 78 h (18% higher than that of free enzyme), the protein retention was 30% and the immobilization yield was 2%. The immobilized laccase has potential for application in the continuous decolourization of textile effluents, where it can be applied into a membrane reactor

Abundance analysis of planet-hosting and debris-disk stars

Abstract: We present an analysis of element abundances in planet-hosting and debrisdisk stars based on high-resolution spectra obtained with the FEROS echelle spectrograph and the 2.2-m ESO telescope at La Silla. Atmospheric parameters and abundance patterns for the stars are determined. A comparison of the abundances is made between planethosting stars, debris-disk stars, and field starshttp://astars2013.inasan.ru/proceedings/publishedVersionFil: Carolina Andrea Chavero. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Astronomía (incluye Astrofísica y Ciencias del Espacio

Abundance Pattern Analysis of Planet-hosting and Debris-disk Stars

Abstract: About 16 % of the main-sequence solar-like stars are surrounded by dusty debris disks (DD). These disks are the detritus of small bodies collisions and their presence is a very strong signpost of planet formation. One of the most interesting characteristics of stars hosting a giant planet is a direct relationship between metallicity and probability of planet formation, which was found to increase with stellar metallicity Gonzalez (1997). Instead, the small planets would form around host stars (HS) with a wide range of metallicities (Buchhave et al. 2012). On the other hand the presence of debris disks is uncorrelated with metallicity (Chavero et al. 2006, Greaves et al. 2006, Maldonado et al. 2012).http://www.aspbooks.org/a/volumes/article_details/?paper_id=36464Fil: Chavero, Carolina Andrea. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Chavero, Carolina Andrea. Conicet. Argentina.Astronomía (incluye Astrofísica y Ciencias del Espacio

Salvia elegans: uma fonte natural de compostos antioxidantes

A espécie Salvia elegans é um arbusto que pertence ao género Salvia, família das Lamiaceae. Várias espécies do mesmo género têm vindo a ser cultivadas para uso na culinária e em medicina tradicional [1]. Devido ao seu cheiro característico, a S. elegans é vulgarmente conhecida por salva ananás e utilizada como condimento ou aromatizante em alimentos. No México esta espécie é popularmente conhecida como “mirto” e tem sido usada na medicina tradicional para tratar afeções do sistema nervoso central [2, 3]. Apesar disso, as suas propriedades biológicas não estão ainda estudadas. Neste trabalho pretende-se clarificar a capacidade antioxidante da espécie S. elegans, bem como proceder à identificação dos seus principais constituintes fenólicos, uma vez que vulgarmente estes compostos se encontram associados a esta propriedade [4]. Para tal, as partes aéreas da planta S. elegans foram extraídas com água quente [5] e o teor de compostos fenólicos totais no extrato foi determinado por uma adaptação do método colorimétrico de Folin-Ciocalteu [6]. A identificação dos compostos fenólicos foi efetuada por análise de cromatografia líquida de alta resolução (HPLC-DAD), acoplada à técnica de espectrometria de massa com ionização por electrospray (ESI-MSn), em modo negativo. Ainda, a capacidade antioxidante do extrato aquoso de S. elegans foi testada através dos testes de captação de radicais livres DPPH•, e do teste do poder redutor. De acordo com o método de Folin-Ciocalteu, os compostos fenólicos no extrato aquoso de S. elegans totalizam 201±46 μg EAG/ mg de extrato. O extrato é particularmente rico em ácido rosmarínico e contém ainda quantidades moderadas de outros derivados do ácido cafeico. Para além disto, o extrato de S. elegans possui uma boa capacidade antioxidante demonstrada pelos métodos de DPPH• e poder redutor. Os resultados obtidos neste estudo permitem sugerir que S. elegans possui grande potencial para ser aplicada como agente antioxidante. Futuramente, pretende-se esclarecer a contribuição individual dos principais constituintes fenólicos do extrato de S. elegans na atividade antioxidante do mesmo

Thin-layer nanofiltration membranes using engineered biopolymers for seawater desalination pre-treatment processes

Nowadays water demand already exceeds supply and water scarcity is a global problem. So it is necessary to develop novel technologies to be able to use poorer quality source waters for drinking water production. Once considered as an expensive, ultimate solution for water supply, desalination is becoming affordable. The two most commonly used seawater desalination methods are Multi-stage Flash Distillation (MSF) and Seawater Reverse Osmosis (SWRO). SWRO is less energy demanding compared to MSF, which makes it economically attractive. However there is no backpulsing of the expensive and delicate reverse osmosis (RO) membranes with air or water, so they are susceptible to fouling, causing the loss of their performance. Therefore cleaning the feed water to the highest level possible by nanofiltration, before it reaches the RO membranes would highly increase the efficiency of the process. Nanofiltration (NF) as a feed pre-treatment step is a pressure driven membrane separation process that takes place on a selective layer formed by a semipermeable membrane with properties between RO and ultrafiltration. The objective of this project is the developement of highly efficient thin-film composite (TFC) membranes for SWRO pre-treatment processes based on low-fouling cyanobacterial extracellular polymeric substances (EPS). TFC membranes combine high flux and mechanical strenght, and they are expected to be the key components of any water purification technology in the future. Cyanobacterial EPS are complex heteropolysaccharides with putative antimicrobial and antiviral properties and a particular affinity to bind metal ions [1,2].Within this work, the unicellular N2-fixing marine cyanobacterium Cyanothece sp. CCY 0110 was chosen for RPS production, since it is among the most efficient released polysaccharide (RPS) producers and the polymer has been previously extensively characterised [3]. RPS was produced by growing Cyanothece CCY 0110 in 10L bioreactors, in conditions previously defined and the polymer was isolated following the standard methodology [3]. A polyvinyl alcohol (PVA) / cyanobacterial EPS blend nanofibrous membranes were fabricated by electrospinning using polyvinylidene fluoride (PVDF) as a basal membrane, in order to obtain thin-layer composite nanofiltration membranes. The production of the nanofibers using EPS and PVA as plasticizer in different ratios was produced in a NF-103 MECC Nanon electrospinning equipment with an applied electric field between 15 and 25 kV and a flow of 0,2 mL/h. Morphological, mechanical, chemical and thermal characterization of the electrospun fibers deposited on the basal membranes, were evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), dynamical and mechanical analysis (DMA), thermogravimetry (TGA) and differential scanning calorimetry (DSC). The AFM and SEM results show the presence of fibers with dimensions between 54 and 121 nm with low bead formation. In the EDS analysis presence of sulfur elements was observed confirming the inclusion of EPS in the nanofibers. The morphology and diameter of the nanofibers were mainly affected by the concentration of the blend solution and the weight ratio of the blend, respectively. The best PVA/EPS nanofibers were achieved in a ratio of 12 % PVA and 0.4 % EPS. The solution conductivity was ranging 1500 to 3500 μS/cm with a viscosity of about 100 to 500 cP. The DMA results confirmed the miscibility of PVA/EPS blends. The elastic modulus of the nanocomposite mats increased significantly as a consequence of the reinforcing effect of EPS. Thermal and mechanical analysis demonstrated that there were strong intermolecular hydrogen bonds between the molecules EPS-PVA in the blends. The heat-treated electrospun blended membranes showed better tensile mechanical properties when compared with PVA alone, and resisted more against disintegration. A lab-scale nanofiltration was performed in a bench stainless steel Sterlitech tangential flow stirred cell (200 mL) connected to an air pressure system that allow pressure driven filtration up to 10 BAR. Bactericidal activity and biofilm formation were tested using Escherichia coli and Sthaphylococcus aureus as pathogenic microorganisms

TiO2 nanostructured films for electrochromic paper based-devices

(H2020-NMP-2015, grant 685758-21D H2020 ERC AdG 787410)Electrochromic titanium dioxide (TiO2) nanostructured films were grown on gold coated papers using a microwave-assisted hydrothermal method at low temperature (80 °C). Uniform nanostructured films fully covered the paper substrate, while maintaining its flexibility. Three acids, i.e., acetic, hydrochloric and nitric acids, were tested during syntheses, which determined the final structure of the produced films, and consequently their electrochromic behavior. The structural characteristics of nanostructured films were correlated with electrochemical response and reflectance modulation when immersed in 1 M LiClO4-PC (lithium perchlorate with propylene carbonate) electrolyte, nevertheless the material synthesized with nitric acid resulted in highly porous anatase films with enhanced electrochromic performance. The TiO2 films revealed a notable contrast behavior, reaching for the nitric-based film optical modulations of 57%, 9% and 22% between colored and bleached states, at 250, 550 and 850 nm, respectively in reflectance mode. High cycling stability was also obtained performing up to 1500 cycles without significant loss of the electrochromic behavior for the nitric acid material. The approach developed in this work proves the high stability and durability of such devices, together with the use of paper as substrate that aggregates the environmentally friendly, lightweight, flexibility and recyclability characters of the substrate to the microwave synthesis features, i.e., simplicity, celerity and enhanced efficiency/cost balance.publishersversionpublishe

Building Better Scientists through Cross-Disciplinary Collaboration in Synthetic Biology: A Report from the Genome Consortium for Active Teaching Workshop 2010

A common problem faced by primarily undergraduate institutions is the lack of funding and material support needed to adequately expose students to modern biology, including synthetic biology. To help alleviate this problem, the Genome Consortium for Active Teaching (GCAT) was founded in 2000 by Malcolm Campbell at Davidson College to bring genomics into the undergraduate curriculum. GCAT’s first tangible activity was to serve as a central clearinghouse both for the purchase and reading of DNA microarrays and for information on how to execute genomics experiments at undergraduate institutions. In response to the evolution of molecular biology in the last decade, Campbell, along with Davidson colleague Laurie Heyer and collaborators Todd Eckdahl and Jeff Poet of Missouri Western State University, organized a Howard Hughes Medical Institute (HHMI)-sponsored GCAT workshop at Davidson in July of 2010. This workshop explored how faculty from multiple disciplines could work together to bring synthetic biology to the undergraduate classroom and laboratory

Building Better Scientists through Cross-Disciplinary Collaboration in Synthetic Biology: A Report from the Genome Consortium for Active Teaching Workshop 2010

A common problem faced by primarily undergraduate institutions is the lack of funding and material support needed to adequately expose students to modern biology, including synthetic biology. To help alleviate this problem, the Genome Consortium for Active Teaching (GCAT) was founded in 2000 by Malcolm Campbell at Davidson College to bring genomics into the undergraduate curriculum. GCAT’s first tangible activity was to serve as a central clearinghouse both for the purchase and reading of DNA microarrays and for information on how to execute genomics experiments at undergraduate institutions. In response to the evolution of molecular biology in the last decade, Campbell, along with Davidson colleague Laurie Heyer and collaborators Todd Eckdahl and Jeff Poet of Missouri Western State University, organized a Howard Hughes Medical Institute (HHMI)-sponsored GCAT workshop at Davidson in July of 2010. This workshop explored how faculty from multiple disciplines could work together to bring synthetic biology to the undergraduate classroom and laboratory