Efecto de la ceniza volcánica sobre la supervivencia de ortópteros en la Patagonia

El objetivo de este trabajo fue evaluar la toxicidad de las cenizas volcánicas del volcán Puyehue-cordón Caulle en la supervivencia de dos especies de Orthoptera: la tucura Dichroplus vittigerum y la langosta verde Brugilis sp. Se utilizaron dos granulometrías de ceniza para evaluar el efecto de las erupciones volcánicas sobre estos insectos. El análisis químico de la ceniza de esta erupción demostró que estas fueron muy abrasivas y estuvieron predominantemente compuestas por fragmentos de sílice (SiO2) y alúmina (Al2O3), dos sustancias con propiedades insecticidas. En el norte de la Patagonia, ambas especies de ortópteros son polífagas, masticadoras de pastos y dicotiledóneas. Los datos de laboratorio mostraron que la exposición sostenida a la ceniza volcánica provocó mortalidad en adultos de ambas especies. La supervivencia de D. vittigerum disminuyó significativamente bajo las dos granulometrías. La supervivencia de Brugilis sp. se redujo significativamente ante la ceniza fina. Estos resultados sugieren que la erupción volcánica, con la consiguiente suspensión del material piroclástico en el aire, pudo haber impactado negativamente sobre las poblaciones de ortópteros mediante la mortalidad de adultos. La ceniza del complejo volcánico Puyehue-Caulle se podría comparar con la aplicación de un insecticida de amplio espectro no persistente, causando una reducción temporal en poblaciones de ortópteros.The aim of this work was to evaluate the ash toxicity from the Puyehue-Cordón Caulle volcanic complex on the survival of two Orthopteran species: the grasshoper Dichroplus vittigerum and the green locust Brugilis sp. Two grain size were used to evaluate the effect of volcanic eruption on these insects. Chemical analyses from this eruption proved that the ashes were very abrasive and predominantly composed of silica shards (SiO2) and aluminia (Al2O3), two substances with insecticidal properties. In northern Patagonia, both orthopteran species are polyphagous chewers on grasses and dicots. The laboratory data showed that sustained exposure to volcanic ash induced mortality in adult grasshoppers. Survival of D. vittigerum significantly decreased once exposed to the two ash granulometries. In turn, Brugilis sp. survival was significantly reduced when exposed to fine grain ashes. These results suggest that the onset of the volcanic eruption with the consequent suspension of the pyroclastic material in the air might negatively impacted these orthopteran due to the mortality of adults. The ash from the Puyehue-Cordón Caulle volcanic complex could be compared to the application of non-persistent and broad spectrum insecticide, causing a temporary reduction in orthopteran populations.Fil: Fernandez Arhex, Valeria Cristina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Amadio, María Emilia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Enriquez, Andrea Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Pietrantuono, Ana Laura. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Becker, Guillermo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; ArgentinaFil: Bruzzone, Octavio Augusto. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

UNR facilitates the interaction of MLE with the lncRNA roX2 during Drosophila dosage compensation

Dosage compensation is a regulatory process that balances the expression of X-chromosomal genes between males (XY) and females (XX). In Drosophila, this requires non-coding RNAs and RNA-binding proteins (RBPs) whose specific functions remain elusive. Here we show that the Drosophila RBP UNR promotes the targeting of the activating male-specific-lethal complex to the X-chromosome by facilitating the interaction of two crucial subunits: the RNA helicase MLE and the long non-coding RNA roX2

Chiral Ru/PNNP complexes in catalytic and stoichiometric electrophilic O- and F-atom transfer to 1,3-dicarbonyl compounds

The asymmetric hydroxylation and fluorination catalyst [Ru(OEt2)2(PNNP)]2+ (PNNP = chiral tetradentate ligand with a P2N2 donor set) reacts with 1,3-dicarbonyl compounds to give dicationic adducts and, upon deprotonation, the corresponding enolato complexes. The relevance of these species to catalytic O- and F-transfer is investigate

Endophytic fungi of the “vassourinha” (Baccharis dracunculifolia D. C., Asteraceae)

All plants host microorganisms, and many of these are endophytic, associating with the plants as mutualists and producing metabolites that make competition with pathogens possible. This reduces herbivory, the attack of insects and pathogens, and protects the plant, which favors its growth. In addition, protection and nutrients are provided to the microorganisms by the host. Studies on the potential of these microorganisms to be used by the pharmaceutical and biotechnological industries are important because they can lead to the discovery of new substances. The goal of this work was to isolate and identify the diversity of endophytic fungi found in Baccharis  dracunculifolia. We obtained 511 fungal isolates from 15 samples, separated them into 12 groups based on morphological characteristics and identified them to the genus level. The colonization rates varied from 78.76±18.45 to 100% (leaves), 77.34 to 96.56% (stems) and 65.71 to 76.34% (roots). Among the 12 groups, the following taxa were found: Penicilium sp. (19.96%), Aspergillus sp. (15.26%), Fusarium sp. (14.49%), Colletotrichum sp. (10.17%), Acremonium sp. (8.61%), Scopulariopsis sp. (5.88%), Nigrospora sp. (4.89%), Cylindrocladium sp. (4.10%), Glomerella sp. (4.10%), Chaetomium sp. (3.13%), Trichoderma sp. (2.35%) and Phomopsis sp. (1.77%) were found. Of the fungi isolated, 5.29% were not identified.(Fungos endofíticos da vassourinha (Baccharis dracunculifolia D. C., Asteraceae). Todas as plantas são hospedeiras de microrganismos, entre os quais muitos podem ser endofíticos, associando-se de forma mutualística, produzindo metabólitos que possibilitam a competição com patógenos, diminuindo a herbivoria, o ataque de insetos e patógenos, protegendo a planta e favorecendo seu crescimento, recebendo em contrapartida proteção e nutrientes do seu hospedeiro. Estudos sobre o potencial destes microrganismos para a área farmacêutica e biotecnológica apresentam-se relevantes, devido à descoberta de novas substâncias para uso humano. Este trabalho teve como objetivo isolar e identificar a diversidade de fungos endofíticos da B. dracunculifolia. Foram obtidos 511 isolados de fungos das quinze amostras avaliadas e agrupados pelas características morfológicas em 12 grupos que foram identificados até o nível de gênero. As taxas de colonização variaram de 78,76±18,45 a 100% (folha), de 77,34 a 96,56% (caule) e de 65,71 a 76,34% (raízes) das plantas. Observou-se também que entre os 12 grupos isolados e identificados encontram-se os gêneros Penicilium sp. (19,96%), Aspergillus sp. (15,26%), Fusarium sp. (14,49%), Colletotrichum sp. (10,17%), Acremonium sp. (8,61%), Scopulariopsis sp. (5,88%), Nigrospora sp. (4,89%), Cylindrocladium sp. (4,10%), Glomerella sp. (4,10%), Chaetomium sp. (3,13%), Trichoderma sp. (2,35%) e Phomopsis sp. (1,77%). 5,29 % dos fungos isolados não foram identificados

Correction for fast pseudo-diffusive fluid motion contaminations in diffusion tensor imaging

In this prospective study, we quantified the fast pseudo-diffusion contamination by blood perfusion or cerebrospinal fluid (CSF) intravoxel incoherent movements on the measurement of the diffusion tensor metrics in healthy brain tissue. Diffusion-weighted imaging (TR/TE = 4100 ms/90 ms; b-values: 0, 5, 10, 20, 35, 55, 80, 110, 150, 200, 300, 500, 750, 1000, 1300 s/mm2, 20 diffusion-encoding directions) was performed on a cohort of five healthy volunteers at 3 Tesla. The projections of the diffusion tensor along each diffusion-encoding direction were computed using a two b-value approach (2b), by fitting the signal to a monoexponential curve (mono), and by correcting for fast pseudo-diffusion compartments using the biexponential intravoxel incoherent motion model (IVIM) (bi). Fractional Anisotropy (FA) and Mean Diffusivity (MD) of the diffusion tensor were quantified in regions of interest drawn over white matter areas, gray matter areas, and the ventricles. A significant dependence of the MD from the evaluation method was found in all selected regions. A lower MD was computed when accounting for the fast-diffusion compartments. A larger dependence was found in the nucleus caudatus (bi: median 0.86 10-3 mm2/s, Δ2b: -11.2%, Δmono: -14.4%; p = 0.007), in the anterior horn (bi: median 2.04 10-3 mm2/s, Δ2b: -9.4%, Δmono: -11.5%, p = 0.007) and in the posterior horn of the lateral ventricles (bi: median 2.47 10-3 mm2/s, Δ2b: -5.5%, Δmono: -11.7%; p = 0.007). Also for the FA, the signal modeling affected the computation of the anisotropy metrics. The deviation depended on the evaluated region with significant differences mainly in the nucleus caudatus (bi: median 0.15, Δ2b: +39.3%, Δmono: +14.7%; p = 0.022) and putamen (bi: median 0.19, Δ2b: +3.1%, Δmono: +17.3%; p = 0.015). Fast pseudo-diffusive regimes locally affect diffusion tensor imaging (DTI) metrics in the brain. Here, we propose the use of an IVIM-based method for correction of signal contaminations through CSF or perfusion

FREQUÊNCIA DE USO DE ÍTEM E INTELIGIBILIDADE DO INGLÊS COMO LÍNGUA FRANCA

A expressão latina que tem sido usada e considerada como a melhor para nomear o inglês do novo milênio é “inglês como língua franca”, ELF, cujo objetivo principal é ser mutuamente inteligível entre seus falantes de diferentes nacionalidades. Este artigo apresenta resultados de estudos de percepção de inteligibilidade, em que falantes de inglês de quatro diferentes nacionalidades - alemães, americanos, chineses e japoneses - produziram os estímulos que foram percebidos por brasileiros, falantes de português e que também falam inglês. Concluiu-se que, para os ouvintes brasileiros, a inteligibilidade de alemães, americanos e chineses foi acima de 75% e é independente de sua língua materna, e o grupo de japoneses apresentou os índices mais baixos. Aspectos relacionados à frequência de uso de item, cuja análise foi feita à luz da Fonologia de Uso e da Teoria dos Exemplares, pareceram ter tido um papel determinante na inteligibilidade: palavras pouco frequentes foram também pouco inteligíveis

O Laptop Educacional na Escola: uma reflexão sobre inclusão digital

Este trabalho consiste em uma reflexão teórica, abordando questões sobre a Educação no contexto das tecnologias digitais e da inclusão digital. Parte-se de um pressuposto teórico que vincula a inclusão digital ao exercício da cidadania no contexto digital, argumentando-se que a promoção desse tipo de ação necessita ultrapassar o âmbito do acesso à tecnologia digital, em busca do desenvolvimento de uma concepção de uso caracterizada pela criticidade, pela reflexão e pelo redimensionamento das práticas frente às realidades da cultura digital. As reflexões tomam por base dois modelos de ações que visam a incluir a escola na cultura digital: o modelo um computador para muitos e o modelo um computador para um (1:1). Em consonância com a base teórica considerada, ponderamos que o segundo modelo referido, presente no programa “Um Computador por Aluno” (UCA), tende a representar maiores possibilidades de inclusão digital. Sustentamos esse argumento postulando que o UCA ultrapassa a disponibilização da tecnologia digital, abarcando a esfera da promoção de concepções críticas e reflexivas de uso, por intermédio da formação de professores e gestores envolvidos

New data on Amynodontidae (Mammalia, Perissodactyla) from Eastern Europe: Phylogenetic and palaeobiogeographic implications around the Eocene-Oligocene transition

Amynodontidae is a family of Rhinocerotoidea (Mammalia, Perissodactyla) known from the late Early Eocene to the latest Oligocene, in North America and Eurasia. European Amynodontidae are very rare, and all remains belong almost exclusively to a single post—Grande Coupure genus from the Oligocene, Cadurcotherium. The “Grande Coupure” defines an extinctions and dispersal-generated originations event in Europe that is nearly contemporaneous with the Eocene-Oligocene transition. Perissodactyls are one of the major groups affected by this event: Palaeotheriidae went almost extinct during this crisis, whereas Rhinocerotidae appeared for the first time in Europe. Study of fossiliferous Eastern-European localities from this age is crucial for the understanding of this crisis. We report here three new localities of Amynodontidae in Eastern Europe. Two of them are dated from the Eocene (Morlaca, Romania; Dorog, Hungary), whereas the other is either Late Eocene or Early Oligocene (Dobârca, Romania). The skull from this latter locality belongs unexpectedly to the same individual as a previously described mandible attributed to “Cadurcodon” zimborensis. As a result, this specimen can be allocated to its proper locality, Dobârca, and is assigned to a new genus, Sellamynodon gen. nov. It is characterised by an extraordinary growth of the nuchal crest, a unique character among amynodontids. Along with this remarkable material from Dobârca, two specimens from another Romanian locality, Morlaca, have been recently discovered and are dated from the Late Eocene. They belong, as well as new material from Dorog (Middle Eocene, Hungary), to the genus Amynodontopsis, also found in North America. The new Hungarian material represents the earliest occurrence of Amynodontidae in Europe. New phylogenetic hypotheses of Rhinocerotoidea are proposed, including the new material presented here, and show that Amynodontidae may be closer to the polyphyletic family ʽHyracodontidaeʼ than to Rhinocerotidae. Amynodontidae, with their deep preorbital fossa and extremely reduced premolars, display in fact a very derived condition, compared to rhinocerotids