Inhibition of catalase activity as an early response of Arabidopsis thaliana cultured cells to the phytotoxin fusicoccin

In Arabidopsis thaliana cells, fusicoccin (FC) treatment induced an early and marked increase in the extracellular H(2)O(2) level. It also increased the huge hypo-osmotic stress-induced oxidative wave and, in addition, prevented the H(2)O(2) peak drop. These effects were apparently not linked to changes in either cytoplasmic pH or cytoplasmic free calcium concentration, since they occurred independently of the activity state of the plasma membrane (PM) H(+)-ATPase and neither influx nor efflux of (45)Ca(2+) was modified by FC. In the presence of diphenylene iodonium (DPI), inhibiting the PM NADPH oxidase presumably responsible for reactive oxygen species (ROS) production, no apoplastic H(2)O(2) development was detected either with or without FC. However, no increase in DPI-sensitive ferricyanide reduction, but rather a gradual decrease, occurred with FC. These results suggested that the H(2)O(2) increase observed with FC was not due to a overproduction of ROS but, more probably, to a reduced capability of FC-treated cells to degrade the H(2)O(2) formed. This view, at first supported by the finding that FC-treated cells failed to break down exogenously supplied H(2)O(2), was clearly confirmed by a series of measurements on exogenous catalase activity, tested in cell-free media of FC-treated samples. This assay, in fact, allowed ascertainment and partial characterization of an as yet unidentified factor increasingly accumulating in the incubation medium of FC-treated cells, behaving as a non-competitive catalase inhibitor and able to reduce markedly the cell's capability for H(2)O(2) scavenging

A representação da performance em estudos etnomusicológicos

Back in the 1970s a number of ethnomusicologists started to elaborate a theoretical reflection on performance as a central issue in the study of music making. This forced them to develop other ways of visualizing music for their analytical purposes. This article deals with how performance has been represented in ethnomusicological studies. I shall discuss how the graphic rendition of a sound recording is simply the mirror of what a scholar perceives, or the consequence of his/her will to emphasise a specific aspect, mediated through the possibilities offered by (and the limits of) the Western semiographic system. After presenting a series of examples on how various scholars chose to graphically visualize musical performance, this paper shows how the contemplation of the strategies used to visualize performance in ethnomusicological studies can be a fruitful way of reflecting upon various topics, namely 1) the impassable limits of score transcription for understanding music as a performative phenomenon; 2) the analysis of the graphic solutions adopted by the ethnomusicologist as a way to better understand their idea of what the performance is; 3) the role played by technology in promoting new analytical approaches and methodologies; 4) analysis in ethnomusicology as an “artisanal process”.A partir de los años setenta algunos etnomusicólogos comenzaron a elaborar una serie de reflexiones teóricas sobre la performance como elemento central para el estudio del music making, lo cual ha conducido a la necesidad de elaborar modalidades alternativas de visualización de la música con finalidad analítica. Este artículo trata sobre cómo se ha representado la performance en los estudios etnomusicológicos. Discutiré si la representación gráfica de una grabación sonora es simplemente el espejo de lo que percibe el estudioso o la consecuencia de su voluntad de enfatizar un aspecto específico, mediada (y limitada) por las posibilidades ofrecidas por el sistema semiográfico occidental. Tras considerar una serie de ejemplos sobre cómo los estudiosos han decidido representar gráficamente la performance musical, este artículo intenta demostrar que el análisis de las estrategias de visualización de la performance en los estudios etnomusicológicos puede ser considerado como un modo útil para reflexionar sobre algunos aspectos, tales como: 1) los límites infranqueables de las transcripciones en pentagrama para entender la música como fenómeno performativo; 2) el análisis de las soluciones gráficas adoptadas por el etnomusicólogo como una estrategia para dar a entender mejor su idea sobre lo que es la performance; 3) el papel que juega la tecnología en la promoción de nuevos enfoques analíticos y metodologías; 4) el análisis en etnomusicología como un “proceso artesanal”A partir dos anos 70 do século XX, alguns etnomusicólogos começaram a elaborar uma série de reflexões teóricas sobre a performance como elemento central para o estudo do music making, as quais conduziram à necessidade de desenvolver outras formas de visualização da música que possam auxiliar os seus objetivos analíticos. Este artigo mostra como se tem representado a performance em estudos etnomusicológicos. Discutirei se a representação gráfica de uma gravação sonora é simplesmente um espelho do entendimento do pesquisador ou a consequência da sua vontade de enfatizar um aspeto específico, mediada (e limitada) pelas possibilidades que oferecem o sistema semiográfico ocidental. Após apresentar uma série de exemplos que mostram como vários académicos decidiram representar graficamente a performance musical, este artigo pretende mostrar que a análise de estratégias de representação da performance em estudos etnomusicológicos pode ser considerada um meio útil para refletir sobre aspetos, tais como: 1) os limites intransponíveis das transcrições em pentagrama para entender a música como fenómeno performativo; 2) a análise das soluções gráficas adotadas pelo etnomusicólogos como uma estratégia para dar a entender melhor a sua ideia sobre o que é a performance; 3) o papel que desempenha a tecnologia na promoção de novos enfoques analíticos e metodologias e; 4) a análise em etnomusicologia como um “processo artesanal”

Аудио-визуелно у јавној етномузикологији и образовању: једно искуство са Сардиније

In recent decades, audiovisual media has been increasingly used in ethnomusicological research. If we consider how scholars use them, four main areas of application can be identified: 1) data analysis, 2) documentary films, 3) public ethnomusicology, 4) educational use. This article presents some audiovisual products on traditional instrumental and vocal music as well as improvised sung poetry in Sardinia (Italy) on which I have worked over the last few years - including the visual representation of musical and poetic forms, and also audiovisual products for exhibitions, museums and multimedia encyclopaedias. My aim is to discuss the role played by ethnomusicologist in conceiving new strategies for the visual representation of the music of oral tradition in different productive contexts and audiovisual outputs

Cultivation of hydrocarbon-tolerant microalgae in flowback wastewaters produced during hydrofracking of impermeable rocks

Huge amounts of Wastewaters (WWs) are produced yearly by the hydrofracking of impermeable rock formations for the extraction of oil or natural gas. Flowback Wastewaters (FWs) are characterized by high contents of inorganic contaminants and hydrocarbons thus representing a relevant threat for the environment. In this work three hydrocarbon-tolerant microalgae have been cultivated in flowback water generated during hydraulic fracturing to investigate their growth kinetics. All three strains could grow in FWs irrespective of the presence of oil hydrocarbons. Biomass productivity varied significantly among the strains. Ochromonas danica achieved a specific growth rate equal to 0.386 day-1 during the exponential phase and a maximum biomass productivity equal to 39 mg L-1 day-1 after 11 days of batch cultivation. Scenedesmus dimorphus was capable to grow in the FWs by achieving a biomass concentration equal to 0.5 g L-1 after about 25 days of cultivation. On the contrary, Prototheca zopfii was strongly affected by the contaminants of FWs. Ultimately, this study demonstrated that specific strains of microalgae could thrive in FWs and thus represent suitable candidates to future research activity aimed to verify the possibility to bio-remediate these harmful WWs

Analysis of the growth of microalgae in batch and semi-batch photobioreactors

Global warming induced by increasing concentrations of greenhouse gases in the atmosphere has become today an important environmental concern. A worldwide problem has become the depletion of petrochemical fuels and the continuous rise in oil prize that call us to make a global effort in order to find alternative energetic sources. A gradual replacement of fossil fuels by renewable energy sources (i.e. biofuels) is needed. In this scenario the use of microalgae can be seen as a possible solution to the problem of global warming since this group of fast-growing unicellular organisms shows several advantages (widespread availability, absent competition with agricultural land, utilization of cheap and abundant nutrient sources, high oil and biomass yields, high quality of the byproducts, generation of biomass for biofuel production with concomitant CO2 sequestration and suitability for wastewater treatments and other industrial plants) which make them one of the most promising and attractive renewable sources for a fully sustainable and lowcarbon economy portfolio. Despite this growing interest, the current microalgae-based technology is still not widespread since it is affected by technical and economic constraints that hinder its full scale-up. Therefore, great R&D efforts are currently undertaken to produce biodiesel at competitive costs and with the required quality starting from microalgae feedstock. In particular given the potential benefits of microalgae, their cultivation should be studied and optimized to make them competitive as fuel producing systems in the global market. Coherently to the scenario above reported, this work is focused on the investigation of two microalgae strains, Nannochloris eucaryotum and Chorella vulgaris. In particular, growth kinetics of these strains are investigated by taking into consideration the effect of medium composition and gas concentration using batch and fed-batch photobioreactors. The aim of this characterization is thus to gain useful information for the cultivation of microalgae in order to optimize the viable production of biofuels and high value-added products at the industrial scale by means of a process which uses flue gases as CO2

Microalgae Growth in Physically Pre-Treated Wastewater Generated During Hydraulic Fracturing

Hydraulic fracturing technique frequently used during gas and oil production generates large amounts of wastewaters (WWs). High cost of the conventional techniques used to treat such waters adversely affect their economic feasibility. Hence, novel technologies that will facilitate remediation and subsequent re-use of these WWs are welcomed. In this study, growth profile of four Oklahoma native microalgae (Geitlerinema carotinosum, Komvophoron sp., Pseudanabaena sp., Picochlorum oklahomensis) cultivated in physically pre-treated flowback and produced water generated during hydraulic fracturing were characterized. A mechanical step based on oil removal by an oil skimmer was introduced during pre-treatment. The experimental results demonstrated that all four strains could grow in pre-treated flowback and produced water. Biomass productivity varied significantly with the microalgae strain and type of the WW used in the growth experiments. The best performing strain, cyanobacterium Komvophoron sp., was able to grow with a specific growth rate ranging from 0.03 to 0.18 day-1 depending on the type of WW. The process was capable of removing ammonium and phosphorus with efficiencies up to 99 and 63%, respectively

Target cell-specific plasticity rules of NMDA receptor-mediated synaptic transmission in the hippocampus

Long-term potentiation and depression of NMDA receptor-mediated synaptic transmission (NMDAR LTP/LTD) can significantly impact synapse function and information transfer in several brain areas. However, the mechanisms that determine the direction of NMDAR plasticity are poorly understood. Here, using physiologically relevant patterns of presynaptic and postsynaptic burst activities, whole-cell patch clamp recordings, 2-photon laser calcium imaging in acute rat hippocampal slices and immunoelectron microscopy, we tested whether distinct calcium dynamics and group I metabotropic glutamate receptor (I-mGluR) subtypes control the sign of NMDAR plasticity. We found that postsynaptic calcium transients (CaTs) in response to hippocampal MF stimulation were significantly larger during the induction of NMDAR-LTP compared to NMDAR-LTD at the MF-to-CA3 pyramidal cell (MF-CA3) synapse. This difference was abolished by pharmacological blockade of mGluR5 and was significantly reduced by depletion of intracellular calcium stores, whereas blocking mGluR1 had no effect on these CaTs. In addition, we discovered that MF to hilar mossy cell (MF-MC) synapses, which share several structural and functional commonalities with MF-CA3 synapses, also undergoes NMDAR plasticity. To our surprise, however, we found that the postsynaptic distribution of I-mGluR subtypes at these two synapses differ, and the same induction protocol that induces NMDAR-LTD at MF-CA3 synapses, only triggered NMDAR-LTP at MF-MC synapses, despite a comparable calcium dynamics. Thus, postsynaptic calcium dynamics alone cannot predict the sign of NMDAR plasticity, indicating that both postsynaptic calcium rise and the relative contribution of I-mGluR subtypes likely determine the learning rules of NMDAR plasticity.This research was supported by the National Institutes of Health (NIH), R01-NS113600, R01-MH125772, R01-MH116673, and R01-MH081935 to PC, and by The Basque Government (IT1620-22), Red de Investigación en Atención Primaria de Adicciones (RIAPAd), Instituto de Salud Carlos III (RD21/0009/0006), and Ministry of Science and Innovation (PID2019-107548RB-I00) to PG

Combining biotechnology with circular bioeconomy: from poultry, swine, cattle, brewery, dairy and urban wastewaters to biohydrogen

ABSTRACT: The ability of microalgae to grow in nutrient-rich environments and to accumulate nutrients from wastewaters (WW) makes them attractive for the sustainable and low-cost treatment of WW. The valuable biomass produced can be further used for the generation of bioenergy, animal feed, fertilizers, and biopolymers, among others. In this study, Scenedesmus obliquus was able to remove nutrients from different wastewaters (poultry, swine and cattle breeding, brewery and dairy industries, and urban) with removal ranges of 95-100% for nitrogen, 63-99% for phosphorus and 48-70% for chemical oxygen demand. The biomass productivity using wastewaters was higher (except for poultry) than in synthetic medium (Bristol), the highest value being obtained in brewery wastewater (1025 mg/(L.day) of freeze-dried biomass). The produced biomass contained 31-53% of proteins, 12-36% of sugars and 8-23% of lipids, regardless of the type of wastewater. The potential of the produced Scenedesmus obliquus biomass for the generation of BioH(2) through batch dark fermentation processes with Enterobacter aerogenes was evaluated. The obtained yields ranged, in mL H-2/g Volatile Solids (VS), from 50.1 for biomass from anaerobically digested cattle WW to 390 for swine WW, whereas the yield with biomass cultivated in Bristol medium was 57.6 mL H-2/gvs.info:eu-repo/semantics/publishedVersio

Ntonobe: musica liturgica tra i fang della Guinea Equatoriale

Ntonobe è la musica eseguita dai complessi vocali e strumentali che animano la liturgia della Chiesa cattolica in Guinea Equatoriale, piccolo paese dell’Africa centro-occidentale. Presenti nella maggior parte delle parrocchie, queste formazioni musicali intonano canti nella lingua dei fang, il principale gruppo etnico del Paese. La loro è una musica di grande impatto anche sul piano visivo, con il coro che canta e danza al ritmo coinvolgente di xilofoni e tamburi. Lo ntonobe è l’esito dell’incontro, avvenuto in questa porzione di Africa, tra diverse culture musicali: da un lato quella dei fang, documentata fin dalla metà del XIX secolo, e dall’altro quella della tradizione eurocolta, portata dai missionari cattolici che evangelizzarono l’area. Nato nell’ambito del progetto di ricerca e documentazione «Musica e devozione popolare tra Sardegna e Guinea Equatoriale», promosso dalla Pontificia Facoltà Teologica della Sardegna e realizzato in collaborazione con l’Università degli Studi di Cagliari, in questo libro la ricerca etnomusicologica incontra la riflessione teologica e la storia della Chiesa per delineare un primo quadro su questa affascinante pratica musicale. Il volume raccoglie i contributi di Ignazio Macchiarella, S. E. Mons. Juan Matogo Oyana, P. Roberto Caria, P. Simon Pedro Ela Ncogo Abang e Marco Lutzu, curatore del volume. Impreziosisce il volume il ricco reportage fotografico realizzato da Roberto Murgia