567 research outputs found
All-Carbon Conductors for Electronic and Electrical Wiring Applications
Electrical conductors based on carbons have recently attracted a growing interest due to the prospect of replacing metals. Electrical conductors without metals could represent not only an alternative for traditional wiring, but also a step forward in the progress and advancing of technology. This result can be achieved by combining high electrical conductivity with other properties, that are dexterity, light weight, environmental stability, high strength and flexibility. As the best mechanical properties, high electrical/thermal conductivity of the assembled fibers are all generally associated with low concentration of defects in the fiber backbone and in the individual carbon âbuilding blocksâ, a special attention is paid to an empirical relationship between morphology/structure/composition and the electrical properties. In this review, starting from the beginning, from the late 19th century, when the carbon filaments became the lights for urban streets, some of the recent developments in the field of âall-carbonâ electrical conductors are discussed. Such conductors can be obtained by assembling nanoscale carbons (i.e., carbon nanotubes, graphene) into macroscopic fibers, yarns and ropes (hereafter fibers). In this perspective, the role played by the chemistry in particular by means of the molecularlevel control and doping, is emphasized. This contribution elucidates most recent results in the field, and envisages new potential applications
Auxin Response Factor 2 (ARF2), ARF3, and ARF4 Mediate Both Lateral Root and Nitrogen Fixing Nodule Development in Medicago truncatula
Auxin Response Factors (ARFs) constitute a large family of transcription factors that mediate auxin-regulated developmental programs in plants. ARF2, ARF3, and ARF4 are post-transcriptionally regulated by the microRNA390 (miR390)/trans-acting small interference RNA 3 (TAS3) module through the action of TAS3-derived trans-acting small interfering RNAs (ta-siRNA). We have previously reported that constitutive activation of the miR390/TAS3 pathway promotes elongation of lateral roots but impairs nodule organogenesis and infection by rhizobia during the nitrogen-fixing symbiosis established between Medicago truncatula and its partner Sinorhizobium meliloti. However, the involvement of the targets of the miR390/TAS3 pathway, i.e., MtARF2, MtARF3, MtARF4a, and MtARF4b, in root development and establishment of the nitrogen-fixing symbiosis remained unexplored. Here, promoter:reporter fusions showed that expression of both MtARF3 and MtARF4a was associated with lateral root development; however, only the MtARF4a promoter was active in developing nodules. In addition, up-regulation of MtARF2, MtARF3, and MtARF4a/b in response to rhizobia depends on Nod Factor perception. We provide evidence that simultaneous knockdown of MtARF2, MtARF3, MtARF4a, and MtARF4b or mutation in MtARF4a impaired nodule formation, and reduced initiation and progression of infection events. Silencing of MtARF2, MtARF3, MtARF4a, and MtARF4b altered mRNA levels of the early nodulation gene nodulation signaling pathway 2 (MtNSP2). In addition, roots with reduced levels of MtARF2, MtARF3, MtARF4a, and MtARF4b, as well as arf4a mutant plants exhibited altered root architecture, causing a reduction in primary and lateral root length, but increasing lateral root density. Taken together, our results suggest that these ARF members are common key players of the morphogenetic programs that control root development and the formation of nitrogen-fixing nodules.Fil: Kirolinko, Cristina Alejandra. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Hobecker, Karen Vanesa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Wen, Jiangqi. Noble Research Institute LLC; Estados UnidosFil: Mysore, Kirankumar S.. Noble Research Institute LLC; Estados UnidosFil: Niebel, Andreas. Centre National de la Recherche Scientifique; Francia. Instituto National de Recherches Agronomiques; Francia. UniversitĂ© de Toulouse; FranciaFil: Blanco, Flavio Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Zanetti, MarĂa Eugenia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; Argentin
The MicroRNA390/TAS3 Pathway Mediates Symbiotic Nodulation and Lateral Root Growth
Legume roots form two types of postembryonic organs, lateral roots and symbiotic nodules. Nodule formation is the result of the interaction of legumes with rhizobia and requires the mitotic activation and differentiation of root cells as well as an independent, but coordinated, program that allows infection by rhizobia. MicroRNA390 (miR390) is an evolutionarily conserved microRNA that targets the Trans-Acting Short Interference RNA3 (TAS3) transcript. Cleavage of TAS3 by ARGONAUTE7 results in the production of trans-acting small interference RNAs, which target mRNAs encoding AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4. Here, we show that activation of the miR390/TAS3 regulatory module by overexpression of miR390 in Medicago truncatula promotes lateral root growth but prevents nodule organogenesis, rhizobial infection, and the induction of two key nodulation genes, Nodulation Signaling Pathway1 (NSP1) and NSP2. Accordingly, inactivation of the miR390/TAS3 module, either by expression of a miR390 target mimicry construct or mutations in ARGONAUTE7, enhances nodulation and rhizobial infection, alters the spatial distribution of the nodules, and increases the percentage of nodules with multiple meristems. Our results revealed a key role of the miR390/TAS3 pathway in legumes as a modulator of lateral root organs, playing opposite roles in lateral root and nodule development.Facultad de Ciencias Exacta
INICIAĂĂO AO BADMINTON - UMA PROPOSTA ATRAVĂS DO PIBID
A prĂĄtica do badminton no ensino fundamental Ă© muito importante para odesenvolvimento motor de nossas crianças. O objetivo desta atividade foi proporcionaratividades que envolvessem os fundamentos bĂĄsicas do badminton, desenvolvendo osaspectos motores, cognitivo, afetivos e sociais de alunos de uma Escola Municipal de SĂŁoMiguel do Oeste/SC. Esta atividade foi realizada com 80 alunos, de 8 a 11 anos de idade,do 4Âș e 5Âș anos matutino e vespertino, sĂ©ries iniciais do ensino fundamental. Utilizou-seda abordagem desenvolvimentista e da abordagem construtivista. Com a falta demateriais para todas as crianças, adaptou-se as raquetes de badminton, trocando asmesmas por raquetes de tĂȘnis de mesa, aprimorando assim as noçÔes espaciais ecoordenativas dos educandos. ApĂłs as aulas ministradas foi possĂvel perceber o avançodos alunos em relação Ă s tĂ©cnicas desenvolvidas, habilidades e capacidades como forçados membros superiores, coordenação motora, agilidade, velocidade de reação e noçãoespacial. ConcluĂmos que a prĂĄtica dos fundamentos bĂĄsicos das modalidades esportivasĂ© fundamental para o ensino fundamental, principalmente nas sĂ©ries iniciais, pois Ă©atravĂ©s do movimento que nossos alunos desenvolveram as habilidades motorasbĂĄsicas, fundamentais para o processo de ensino e aprendizagem. O badminton auxiliouno desenvolvimento motor, alĂ©m de contribuir de forma significativa em relação aosaspectos cognitivos, afetivos e sociais, que a modalidade possibilita. Salienta-se que asaulas com o conteĂșdo de badminton foram realizadas via PIBID. O programa possibilitaque o acadĂȘmico vivencie a realidade escolar atravĂ©s de projetos de iniciação a docĂȘncia,pois, a partir dele Ă© possĂvel fazer a aproximação teĂłrica do campo empĂrico
Reprogramming of root cells during nitrogen-fixing symbiosis involves dynamic polysome association of coding and noncoding RNAs
Translational control is a widespread mechanism that allows the cell to rapidly modulate gene expression in order to provide flexibility and adaptability to eukaryotic organisms. We applied translating ribosome affinity purification combined with RNA sequencing to characterize translational regulation of mRNAs at early stages of the nitrogen-fixing symbiosis established between Medicago truncatula and Sinorhizobium meliloti. Our analysis revealed a poor correlation between transcriptional and translational changes and identified hundreds of regulated protein-coding and long noncoding RNAs (lncRNAs), some of which are regulated in specific cell types. We demonstrated that a short variant of the lncRNA Trans-acting small interference RNA3 (TAS3) increased its association to the translational machinery in response to rhizobia. Functional analysis revealed that this short variant of TAS3 might act as a target mimic that captures microRNA390, contributing to reduce trans acting small interference Auxin Response Factor production and modulating nodule formation and rhizobial infection. The analysis of alternative transcript variants identified a translationally upregulated mRNA encoding subunit 3 of the SUPERKILLER complex (SKI3), which participates in mRNA decay. Knockdown of SKI3 decreased nodule initiation and development, as well as the survival of bacteria within nodules. Our results highlight the importance of translational control and mRNA decay pathways for the successful establishment of the nitrogen-fixing symbiosis.Fil: Traubenik, Laura Soledad. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Reynoso, Mauricio Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Hobecker, Karen Vanesa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Lancia, Marcos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Hummel, Maureen. University of California; Estados UnidosFil: Rosen, Benjamin. J. Craig Venter Institute; Estados UnidosFil: Town, Christopher. J. Craig Venter Institute; Estados UnidosFil: Bailey Serres, Julia. University of California; Estados UnidosFil: Blanco, Flavio Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; ArgentinaFil: Zanetti, MarĂa Eugenia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; Argentin
The MicroRNA390/TAS3 Pathway Mediates Symbiotic Nodulation and Lateral Root Growth
Legume roots form two types of postembryonic organs, lateral roots and symbiotic nodules. Nodule formation is the result of the interaction of legumes with rhizobia and requires the mitotic activation and differentiation of root cells as well as an independent, but coordinated, program that allows infection by rhizobia. MicroRNA390 (miR390) is an evolutionarily conserved microRNA that targets the Trans-Acting Short Interference RNA3 (TAS3) transcript. Cleavage of TAS3 by ARGONAUTE7 results in the production of trans-acting small interference RNAs, which target mRNAs encoding AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4. Here, we show that activation of the miR390/TAS3 regulatory module by overexpression of miR390 in Medicago truncatula promotes lateral root growth but prevents nodule organogenesis, rhizobial infection, and the induction of two key nodulation genes, Nodulation Signaling Pathway1 (NSP1) and NSP2. Accordingly, inactivation of the miR390/TAS3 module, either by expression of a miR390 target mimicry construct or mutations in ARGONAUTE7, enhances nodulation and rhizobial infection, alters the spatial distribution of the nodules, and increases the percentage of nodules with multiple meristems. Our results revealed a key role of the miR390/TAS3 pathway in legumes as a modulator of lateral root organs, playing opposite roles in lateral root and nodule development.Facultad de Ciencias Exacta
Construção e validação de modelos de regressĂŁo a partir de espectros NIR para predição da composição da cana-de-açĂșcar, farelo de soja e fubĂĄ de milho
Objetivou-se desenvolver e avaliar modelos de regressĂŁo para a predição da composição quĂmica da cana-de-açĂșcar, farelo de soja e fubĂĄ de milho por NIR portĂĄtil aliado a tĂ©cnicas quimiomĂ©tricas. Foram utilizadas 95 amostras de cana-de-açĂșcar, 92 amostras de farelo de soja e 120 amostras de fubĂĄ de milho. ApĂłs a moagem das amostras, foi realizada aquisição dos espectros de cada amostra. Os valores referĂȘncia foram obtidos atravĂ©s de anĂĄlises quĂmicas convencionais. Para construção dos modelos, foi utilizada a regressĂŁo por quadrados mĂnimos parciais e a validação cruzada leave one out. Os modelos com menor raiz quadrada do erro quadrĂĄtico mĂ©dio da validação cruzada foram submetidos a validação externa. Para avaliar a qualidade de ajuste dos modelos, os valores preditos foram comparados com os valores obtidos pelos mĂ©todos laboratoriais convencionais. Os modelos construĂdos estimaram corretamente todos os constituintes avaliados para a cana-de-açĂșcar, farelo de soja e fubĂĄ de milho (P â„ 0,056). Os modelos construĂdos para predição dos teores de amostra seca em estufa a 55°C (ASA) e a 105°C (ASE), matĂ©ria seca total (MS), matĂ©ria orgĂąnica (MO), fibra insolĂșvel em detergente neutro (FDN), FDN corrigida para cinzas e proteĂna (FDNcp), proteĂna insolĂșvel em detergente neutro (PIDN), fibra insolĂșvel em detergente ĂĄcido (FDA), proteĂna bruta (PB), carboidratos nĂŁo fibrosos (CNF) e nutrientes digestĂveis totais (NDT) da cana-de-açĂșcar; ASE, MO, FDN, FDA, FDN indigestĂvel (FDNi), PB, NDT e amido de farelo de soja; e ASE, PB do fubĂĄ de milho apresentaram elevada acurĂĄcia e precisĂŁo (R2 â„ 0,50 e CCC â„ 0,60). Contudo os modelos construĂdos para predição dos teores de cinzas insolĂșveis em detergente neutro (CIDN) da cana-de-açĂșcar; extrato etĂ©reo (EE) e CIDN do farelo de soja; e FDN, FDNi, CIDN, CNF e EE do fubĂĄ de milho foram acurados, porĂ©m pouco precisos (R2 â„ -0,04 e CCC â„ 0,03). Conclui-se que os modelos de regressĂŁo por NIR portĂĄtil estimaram acuradamente e, portanto, sĂŁo recomendados para estimar a composição quĂmica da cana-de-açĂșcar, farelo de soja e fubĂĄ de milho
CRISPR interference to evaluate modifiers of C9ORF72-mediated toxicity in FTD
Treatments for neurodegenerative disease, including Frontotemporal dementia (FTD) and Amyotrophic lateral sclerosis (ALS), remain rather limited, underscoring the need for greater mechanistic insight and disease-relevant models. Our ability to develop novel disease models of genetic risk factors, disease modifiers, and other FTD/ALS-relevant targets is impeded by the significant amount of time and capital required to develop conventional knockout and transgenic mice. To overcome these limitations, we have generated a novel CRISPRi interference (CRISPRi) knockin mouse. CRISPRi uses a catalytically dead form of Cas9, fused to a transcriptional repressor to knockdown protein expression, following the introduction of single guide RNA against the gene of interest. To validate the utility of this model we have selected the TAR DNA binding protein (TDP-43) splicing target, stathmin-2 (STMN2). STMN2 RNA is downregulated in FTD/ALS due to loss of TDP-43 activity and STMN2 loss is suggested to play a role in ALS pathogenesis. The involvement of STMN2 loss of function in FTD has yet to be determined. We find that STMN2 protein levels in familial FTD cases are significantly reduced compared to controls, supporting that STMN2 depletion may be involved in the pathogenesis of FTD. Here, we provide proof-of-concept that we can simultaneously knock down Stmn2 and express the expanded repeat in the Chromosome 9 open reading frame 72 (C9ORF72) gene, successfully replicating features of C9-associated pathology. Of interest, depletion of Stmn2 had no effect on expression or deposition of dipeptide repeat proteins (DPRs), but significantly decreased the number of phosphorylated Tdp-43 (pTdp-43) inclusions. We submit that our novel CRISPRi mouse provides a versatile and rapid method to silence gene expression in vivo and propose this model will be useful to understand gene function in isolation or in the context of other neurodegenerative disease models
Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at âs = 13 TeV
Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (dÌ t) and chromomagnetic (ÎŒÌ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fbâ1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ÂŻ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ÂŻ final states. The values found for the parameters are AFB(1)=0.048â0.087+0.095(stat)â0.029+0.020(syst),ÎŒÌt=â0.024â0.009+0.013(stat)â0.011+0.016(syst), and a limit is placed on the magnitude of | dÌ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.
Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions
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