Characterization of industrial TNT in ammunition shells: An in-depth study of artificial aging effects using Fourier-Transform infrared spectroscopy and gas chromatography-mass spectrometry.

In this study, we comprehensively investigated the degradation of industrial trinitrotoluene (TNT), focusing on the effects of aging and direct contact with steel surfaces, mirroring real-world usage conditions. While practical knowledge exists regarding this degradation, the existing literature lacks in-depth insights into the underlying processes. To address this gap, we conducted experiments using small steel samples, representative of military ammunition casings, which were coated with TNT and subjected to 30 days of heating at 75 °C under vacuum conditions. A subset of these samples was coated with a protective red alkyd paint. After the aging process, the TNT was carefully removed from the metal surfaces and subjected to a comprehensive analysis encompassing scanning electron microscopy, Fourier-transform infrared spectroscopy, and gas chromatography-mass spectrometry. Our results reveal a remarkable preservation of the chemical integrity of industrial TNT, even in the presence of thermal stress and direct steel contact. Although superficial changes were observed in the TNT's appearance, all analytical data consistently demonstrated the maintenance of its chemical composition. Notably, the sole change in composition was attributed to the presence of degradation products associated with the alkyd paint coating, rather than intrinsic TNT degradation. These findings underscore the negligible impact of degradation processes on TNT in scenarios involving the solid-phase thermal stress of TNT in direct contact with metal, significantly enhancing our understanding of TNT safety when packaged within steel artifacts-a common context in military ammunition.

Chemical analysis of marine microdebris pollution in macroalgae from the coastal areas of Argentina.

Marine microdebris (MDs, <5 mm) and mesodebris (MesDs, 5-25 mm), consist of various components, including microplastics (MPs), antifouling or anticorrosive paint particles (APPs), and metallic particles (Mmps), among others. The accumulation of these anthropogenic particles in macroalgae could have significant implications within coastal ecosystems because of the role of macroalgae as primary producers and their subsequent transfer within the trophic chain. Therefore, the objectives of this study were to determine the abundance of MDs and MesDs pollution in different species of macroalgae (P. morrowii, C. rubrum, Ulva spp., and B. minima) and in surface waters from the Southwest Atlantic coast of Argentina to evaluate the ecological damage. MDs and MesDs were chemically characterized using µ-FTIR and SEM/EDX to identify, and assess their environmental impact based on their composition and degree of pollution by MPs, calculating the Polymer Hazard Index (PHI). The prevalence of MDs was higher in foliose species, followed by filamentous and tubular ones, ranging from 0 to 1.22 items/g w.w. for MPs and 0 to 0.85 items/g w.w. for APPs. It was found that macroalgae accumulate a higher proportion of high-density polymers like PAN and PES, as well as APPs based on alkyd, PMMA, and PE resins, whereas a predominance of CE was observed in surrounding waters. Potentially toxic elements, such as Cr, Cu, and Ti, were detected in APPs and MPs, along with the presence of epiplastic communities on the surface of APPs. According to PHI, the presence of high hazard score polymers, such as PAN and PA, increased the overall risk of MP pollution in macroalgae compared to surrounding waters. This study provided a baseline for MDs and MesDs abundance in macroalgae as well as understanding the environmental impact of this debris and their bioaccumulation in the primary link of the coastal trophic chain.

Spontaneous Pneumomediastinum in a 15-Year-Old Adolescent After Unintended Overexposure to Paint Diluent (Thinner) Fumes: First Reported Case.

Spontaneous pneumomediastinum (SPM) is the presence of air in the mediastinal interstices in the absence of any surgical or medical procedure, chest trauma, or mechanical ventilation. SPM can occur during vigorous Valsalva maneuvers, such as weight lifting, coughing fits, hyperemesis gravidarum, and so on, or during inhalation of illicit substances or toxic agents, as a result of an abrupt increase in pressure in the tracheal tree. Preexisting underlying lung disease may be a contributing factor. In the present case, we report for the first time an SPM due to accidental overexposure to paint thinner in a 15-year-old male from a low-income rural family. He was offered a job painting the inside of a house, which he accepted to earn some money for the family household. However, due to his inexperience, he overdosed on a can of paint with thinner. About 2 h after starting work, he began to feel increasingly severe chest pain and had to be rushed to the local level one basic hospital by his parents. Physical examination revealed subcutaneous emphysema over the supraclavicular area and crackles in the precordial area. Chest radiographs showed a pneumomediastinum. In retrospect, the patient denied coughing or sneezing attacks after exposure. He was transferred to a regional tertiary hospital for further diagnostic evaluation to rule out airway/esophageal perforation. Chest computed tomography confirmed underlying SPM and subcutaneous emphysema. The oesophagogram and bronchoscopy were unremarkable. SPM, possibly secondary to overexposure to thinner vapors, a hydrocarbon-based compound, was the final diagnosis. The patient was discharged asymptomatic on day 5.

Plastic and paint debris in marine protected areas of Peru.

Contamination with anthropogenic debris, such as plastic and paint particles, has been widely investigated in the global marine environment. However, there is a lack of information regarding their presence in marine protected areas (MPAs). In the present study, the abundance, distribution, and chemical characteristics of microplastics (MPs; <5 mm), mesoplastics (MePs; 5-25 mm), and paint particles were investigated in multiple environmental compartments of two MPAs from Peru. The characteristics of MPs across surface water, bottom sediments, and fish guts were similar, primarily dominated by blue fibers. On the other hand, MePs and large MPs (1-5 mm) were similar across sandy beaches. Several particles were composite materials consisting of multiple layers confirmed as alkyd resins by Fourier-transformed infrared spectroscopy, which were typical indicators of marine coatings. The microstructure of paint particles showed differentiated topography across layers, as well as different elemental compositions. Some layers displayed amorphous structures with Ba-, Cr-, and Ti-based additives. However, the leaching and impact of potentially toxic additives in paint particles require further investigation. The accumulation of multiple types of plastic and paint debris in MPAs could pose a threat to conservation goals. The current study contributed to the knowledge regarding anthropogenic debris contamination in MPAs and further elucidated the physical and chemical properties of paint particles in marine environments. While paint particles may look similar to MPs and MePs, more attention should be given to these contaminants in places where intense maritime activity takes place.

Super-Resolved FRET Imaging by Confocal Fluorescence-Lifetime Single-Molecule Localization Microscopy.

Fluorescence Resonance Energy Transfer (FRET)-based approaches are unique tools for sensing the immediate surroundings and interactions of (bio)molecules. FRET imaging and Fluorescence Lifetime Imaging Microscopy (FLIM) enable the visualization of the spatial distribution of molecular interactions and functional states. However, conventional FLIM and FRET imaging provide average information over an ensemble of molecules within a diffraction-limited volume, which limits the spatial information, accuracy, and dynamic range of the observed signals. Here, an approach to obtain super-resolved FRET imaging based on single-molecule localization microscopy using an early prototype of a commercial time-resolved confocal microscope is demonstrated. DNA Points Accumulation for Imaging in Nanoscale Topography with fluorogenic probes provides a suitable combination of background reduction and binding kinetics compatible with the scanning speed of usual confocal microscopes. A single laser is used to excite the donor, a broad detection band is employed to retrieve both donor and acceptor emission, and FRET events are detected from lifetime information.

Conductive carbon paint: An efficient way to electrodeposit metallic nanowires by using porous membranes.

The present work demonstrates that conductive carbon paint, used for sample preparation in electron microscopy, can be a more straightforward and as-effective substitute for the metallic layer deposition usually used for the electrodeposition of metallic nanowires within porous membranes. AFM images demonstrated the good surface quality of the carbon layer. Raman spectroscopy confirmed the high crystallinity of carbon and high density of π-electrons. The electrical conductivity of the carbon layer was estimated using the linear sweep voltammetry technique. This new cathode was employed to grow continuous (Ni) and composition-modulated (Ni/Cu) nanowires within alumina templates, starting from aqueous solutions of Ni2+ and Cu2+ mixed salts. The obtention of metallic copper and nickel, and their separation can be readily observed by scanning electron microscopy and elemental mapping by EDS.

ZnO recovered from spent alkaline batteries as antimicrobial additive for waterborne paints.

Biocides are employed to prevent biodeterioration in waterborne paints. In the present study, we used zinc oxide nanoparticles (obtained from spent alkaline batteries) as biocide for indoor waterborne paint at 1.5% of the total solid content in paint. Two different zinc oxides synthesized from spent alkaline batteries, which showed photocatalyst activity, were employed as an antimicrobial agents. After leaching the anode of alkaline batteries, zinc was precipitated from the leachate liquor by introducing oxalic acid (O-ZnO) or sodium carbonate (C-ZnO). The antimicrobial properties of the prepared oxides were tested against Staphylococcus aureus (bacteria), Chaetomium globosum, and Aspergillus fumigatus (fungi) using agar well diffusion method. C-ZnO inhibited the growth of all the strains studied and presented enhanced activity than O-ZnO. The better performance as antimicrobial agent of C-ZnO compared to O-ZnO was attributed to its lower crystallite size, higher amount of oxygen monovacancies, and to its lower band gap energy. The oxide with the best performance in antimicrobial activity, C-ZnO, was employed for the formulation of waterborne acrylic paints. It was observed that 1.5% C-ZnO improved the antifungal properties and antibacterial properties compared to the control sample.

Tracking synthetic microdebris contamination in a highly urbanized estuary through crabs as sentinel species: An ecological trait-based approach.

Synthetic microdebris (particles of <5 mm) are a worldwide concern because they can affect the community structure of the aquatic ecosystems, organisms, and even food webs. For the biomonitoring of synthetic microdebris (especially microplastics, MPs), mainly benthic invertebrates are used, but crabs have been less studied in the literature. We studied the synthetic microdebris contamination in water, sediments, and three representative intertidal crabs (Neohelice granulata, Cyrtograpsus angulatus and Leptuca uruguayensis) with different lifestyles from the Bahía Blanca estuary, Argentina. The results obtained show the presence of cotton-polyamide (PA), polyethylene (PE), and polyethylene terephthalate (PET) in surface waters. In sediments, we identified cellulose modified (CE), polyester (PES), polyethylene (PE), and alkyd resin, while in crabs, cotton-PA and CE were the predominant ones. The MPs abundance ranged from 8 to 68 items L-1 in surface water, from 971 to 2840 items Kg-1 in sediments, and from 0 to 2.58 items g-1 ww for the three species of crabs. Besides, paint sheets ranged from 0 to 17 in the total samples, with Cr, Mo, Ti, Pb, Cu, Al, S, Ba and Fe on their surface. There were significant differences between the microdebris abundances in the abiotic matrices but not among crabs species. The ecological traits of the different crabs helped to understand the accumulation of synthetic microdebris, an important characteristic when determining the choice of a good biomonitor.

Daltonismo racional / Rational Daltonism / Daltonismo Racional

Con la técnica de aerografía sobre madera, se crea la obra "Daltonismo Racional", composición planteada en orden cartesiano, iniciando en el plano izquierdo superior con el panel rojo de línea totalmente quebrada, en constante zigzag, seguido a la derecha por el panel verde con gráfico de cigarrillo humeante; luego, en el sector izquierdo debajo del panel rojo encontramos el panel verde con la botella de licor y, finalmente, en la zona derecha inferior hallamos el panel con el gráfico del monitor rojo y línea blanca horizontal. Respecto a sus dimensiones, corresponde a un políptico conformado por cuatro módulos cuadrados, de 36 cm x 36 cm x 7 cm de profundidad. Entre los módulos hay un espacio de 20 cm, lo cual permite la formación de una cruz, por los dos espacios cruzados perpendicularmente. La obra tiene un carácter contestatario, frente a la manera como se pretende financiar la salud pública, debido a que los impuestos generados por la venta y consumo de alcohol y cigarrillos, se destinan para la salud, lo que nos lleva a una paradoja: ¿es razonable pensar que a través del detrimento de la salud de las personas que consumen licores y cigarrillos, se intente solucionar los problemas de salud?, ¿no es acaso la prevención y el no consumo de estas sustancias, lo que nos permite cultivar un mejor estado de salud?

With the technique of airbrushing on wood, the work "Rational Daltonism" is created. This is laid out in Cartesian order, starting on the upper left plane with the red panel with a totally broken line, in constant zigzag, followed to the right by the green panel with a graphic of a smoking cigarette; then, in the left sector below the red panel we find the green panel with the liquor bottle and, finally, in the lower right area we find the panel with the red monitor graphic and horizontal white line. Regarding its dimensions, it corresponds to a polyptych made up of four square modules, 36 cm x 36 cm x 7 cm deep. Between the modules there is a space of 20 cm, which allows the formation of a cross, by the two spaces crossed perpendicularly. The work has an anti-establishment character, as opposed to the way in which public health is intended to be financed, because the taxes generated by the sale and consumption of alcohol and cigarettes are destined for health, which leads us to a paradox: Is it reasonable to think that there is an attempt to solve health problems through the health detriment of the people who consume liquor and cigarettes? Is not prevention and not consuming these substances what allows us to cultivate a better health condition?

Com a técnica de aerografia sobre madeira, é criada a obra Daltonismo Racional. Esta está disposta em ordem cartesiana, iniciando no plano superior esquerdo com o painel vermelho com uma linha totalmente quebrada, em constante ziguezague, seguido à direita pelo painel verde com o gráfico de um cigarro fumando; em seguida, no setor esquerdo abaixo do painel vermelho encontramos o painel verde com a garrafa de licor e, finalmente, na área inferior direita encontramos o painel com o gráfico do monitor vermelho e linha branca horizontal. Quanto às suas dimensões, corresponde a um políptico composto por quatro módulos quadrados, com 36 cm x 36 cm x 7 cm de profundidade. Entre os módulos existe um espaço de 20 cm, que permite a formação de uma cruz, pelos dois espaços cruzados perpendicularmente. La obra tiene un carácter contestatario, frente a la manera como se pretende financiar la salud pública, debido a que los impuestos generados por la venta y consumo de alcohol y cigarrillos, se destinan para la salud, lo que nos lleva a una paradoja: es razonable pensar que a través del detrimento de la salud de las personas que consumen licores y cigarrillos, se intente solucionar los problemas de salud?, no es acaso la prevención y el no consumo de estas sustancias, lo que nos permite cultivar un mejor Estado de saúde?

NMR and other molecular and elemental spectroscopies for the characterization of samples from an outdoor mural painting by Siqueiros.

This study presents the use of high resolution Nuclear Magnetic Resonance (NMR) as an outstanding tool for identifying with accuracy the structure of the polymers used as binders and the additives used as plasticizers in samples from a mural painted by David Alfaro Siqueiros between 1964 and 1972, an important period in which his artistic production has not been previously studied. Additionally, the presence of some organic pigments was detected. The mural Trazos de composición piramidal currently located outside of Siqueiros' studio La Tallera, in Cuernavaca Morelos (Mexico) was an artistic experiment done by Siqueiros to test outdoor painting. Eight micro-samples of paint were thoroughly analyzed by Optical Microscopy (OM), Scanning Electron Microscopy - Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fiber Optics Reflectance Spectra (FORS), Transmission Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance mode (FTIR-ATR) and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS). Through these studies, contrasted with an historical investigation, we demonstrate that the samples present a multi-layered and complex painting system because Siqueiros made at least two versions of the painting. The multi-layered structure and the variable composition of each layer challenged the application of several analytical methodologies traditionally used for cultural heritage materials. In one sample, each layer was separated and they were studied in detail by FTIR-ATR, Py-GC/MS and NMR. This study revealed the presence of two main binders: acrylics in the first layers and nitrocellulose in the last one, also some phthalates and fatty acids were detected as additives. Inorganic pigments and fillers were identified as titanium dioxide and iron red oxide as well as diatoms and carbonates. The main contribution of this study, where NMR spectroscopy was applied for the first time in modern mural painting analysis, is the characterization of the materials used by Siqueiros during the last years of his artistic production.

Mexican paradise under threat: The impact of antifouling biocides along the Yucatán Peninsula.

Levels of booster biocides (Irgarol, diuron, chlorothalonil, dichlofluanid and DCOIT), organotins (TBT, DBT, MBT, TPhT, DPhT and MPhT) and antifouling paint particles (APPs) were assessed in sediments of sites under the influence of maritime activities along the coastal zone of the Yucatán Peninsula, Mexico. Imposex incidence and organotin levels were also evaluated in seven caenogastropod species. The incidence of imposex was detected in five species from sites nearby fishing harbors and marinas, including the first reports to Gemophos tinctus and Melongena bispinosa. Butyltins levels were higher than phenyltins in gastropod tissues, sediments, and APPs. Regarding booster biocides, chlorothalonil was the most frequently detected compound and DCOIT was the most abundant biocide in sediments. DCOIT levels were registered in APPs from fishing harbors and marina areas. In addition, the highest levels of TBT, Irgarol, diuron and DCOIT exceeded the threshold limits set by international sediment quality guidelines, indicating that toxic effects could be expected in some of the studied areas, thus being a potential threat to marine life. Based on such outputs, Mexico urgently needs to adopt restrictive actions aiming at conserving the rich biological heritage of the Yucatán Peninsula.

Discrimination of white automotive paint samples using ATR-FTIR and PLS-DA for forensic purposes.

The consequences of a hit-and-run car crash are significant and may include serious injuries to the victims, health system overload and even victim's death. The vehicle and driver identification are often challenging for local law enforcement. The aim of this study was to develop a methodology to discriminate between automotive paint samples according to the make of the vehicle and its color shade. 143 white samples (collected at traffic accident scenes) were analyzed in situ by Fourier transform infrared spectroscopy with attenuated total reflectance (ATR-FTIR) and coupled microscopy. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed for data analysis. The samples were split into three groups: calibration set, validation set and external test set. The figures of merit were calculated to assess the quality of the model. Sensitivity, specificity, and efficiency rates were, respectively, 98,9%, 98.4% and 98.6%, for the calibration set. For the validation group, the classification accuracy was 100%. Correct classification rates for the internal validation set and external test set were 100% and 79.1% respectively. The technique is clean, fast, relatively low-cost, and non-destructive. Damaged regions of the samples were avoided by using the attached microscope. Limiting the age of the samples to a maximum of 10 years was enough to avoid misclassifications due to the natural degradation and weathering of the sample. Since the external test group is formed by underrepresented classes, its correct classification rate (79.1%) can be potentially improved at any time, by including and analyzing more samples.

Errata de: La trama de la enseñanza. Notas para pensar las secuencias desde algunas relaciones con ejercicios de pintura: el caso dela gimnasia escolar / Errata de: A trama do ensino. Notas para pensar as sequências a partir de algumas relações com exercícios de pintura: o caso da ginástica escolar / Erratum to: The fabric of teaching. Notes to think about the sequences as from some relationship with painting exercises: the case of school gymnastics

El presente artículo se elabora en el marco del trabajo del grupo de investigación Docencia, Escuela. Arte y Educación del Cuerpo (DESAREC), del Instituto Superior de Educación Física (ISEF), de la Universidad de la República (Udelar) Uruguay. Objetivo:Elaborar la revisión de un artículo publicado en 2006 en la revista IsefDigital,que se ocupó de problematizar la selección y secuenciación de contenidos en educación física. Resultados y discusión:En esta ocasión se incorporan nuevos elementos que ponen en diálogo asuntos propios sobre el ejercicio de pensar las secuenciaciones didácticas y algunos estudios y ejercicios de pintura que, desde los entre-lugares con el arte, entendemos que pueden aportar a la hora de pensar la docencia y la enseñanza desde otra perspectiva de exploración posible. A partir de estas relaciones, se presenta un ejercicio de secuenciación para el caso de la gimnasia escolar, intentando de esta manera, despejar algunos problemas que tiene el campo en general, tanto en su conceptualización como en su enseñanza. Consideraciones finales: De esta manera se esboza una perspectiva posible de conceptualización sobre la escuela como forma y, por tanto, sobre una mirada del oficio docente que se configura en ella y con ella, y que implica un cierto tipo de relación estudiosa y atenta con nuestra materia de enseñanza, que en esta caso se trata de la gimnasia escolar.

Este artigo é elaborado no âmbito do grupo de pesquisa Ensino, Escola, Arte e Educação do Corpo (DESAREC) do Instituto Superior de Educação Física (ISEF) da Universidade da República (Udelar), Uruguai. Objetivo:Revisão de um artigo publicado em 2006 na revista Isefdigital, que tratava do problema da seleção e sequenciamento de conteúdos na educação física. Resultados e discussão:Nesta ocasião, são incorporados novos elementos que trazem em diálogo questões próprias ao desenho de sequências de ensino com alguns estudos e exercícios de pintura que, a partir dos entre-lugares com a arte, entendemos que podem contribuir para pensar a docência e o ensino desde outra perspectiva de exploração possível. A partir dessas relações, apresenta-se um exercício de sequenciamento para o caso da ginástica escolar, tentando assim esclarecer alguns problemas que a área apresenta em geral, tanto em sua conceituação quanto em seu ensino. Considerações finais: Dessa forma delineia-se uma perspectiva conceitual da escola como forma pedagógica e, portanto, sobre uma visão particular da profissão docente que se configura nela e com ela, o que implica certotipo de relação estudiosa e atenta com a nossa matéria de ensino.

This article has been prepared within the framework of the Teaching, School, Art and Education of the Body (DESAREC) research group of the Higher Institute of Physical Education (ISEF) of the University of the Republic (Udelar),Uruguay. Objetive:To elaborate a revision of an article published in 2006 in the IsefDigitalmagazine, which dealt with problematizing the selection and sequencing of content in physical education. Discussion and results:On this occasion, new elements are incorporated that put in dialogue issues related to the design of teaching sequences with some studies and painting exercises that, from the between-places with art, we understand they can contribute to consider teaching and education from another possible perspective of exploration. Based on these relationships, a sequencing exercise is presented for the case of school gymnastics, thus trying to clear up some problems that the field has in general, both in its conceptualization and in its teaching.FinalConsiderations:Following that, a conceptual perspective of school as a pedagogical form is outlined and therefore, on a particular view of the teaching profession that is configured in and with it, implying a certain type of studious and attentive relationship with our teaching subject.

La trama de la enseñanza. Notas para pensar las secuencias desde algunas relaciones con ejercicios de pintura: el caso dela gimnasia escolar / A trama do ensino. Notas para pensar as sequências a partir de algumas relações com exercícios de pintura: o caso da ginástica escolar / The fabric of teaching. Notes to think about the sequences as from some relationship with painting exercises: the case of school gymnastics

El presente artículo se elabora en el marco del trabajo del grupo de investigación Docencia, Escuela. Arte y Educación del Cuerpo (DESAREC), del Instituto Superior de Educación Física (ISEF), de la Universidad de la República (Udelar) Uruguay. Objetivo:Elaborar la revisión de un artículo publicado en 2006 en la revista IsefDigital,que se ocupó de problematizar la selección y secuenciación de contenidos en educación física. Resultados y discusión:En esta ocasión se incorporan nuevos elementos que ponen en diálogo asuntos propios sobre el ejercicio de pensar las secuenciaciones didácticas y algunos estudios y ejercicios de pintura que, desde los entre-lugares con el arte, entendemos que pueden aportar a la hora de pensar la docencia y la enseñanza desde otra perspectiva de exploración posible. A partir de estas relaciones, se presenta un ejercicio de secuenciación para el caso de la gimnasia escolar, intentando de esta manera, despejar algunos problemas que tiene el campo en general, tanto en su conceptualización como en su enseñanza. Consideraciones finales: De esta manera se esboza una perspectiva posible de conceptualización sobre la escuela como forma y, por tanto, sobre una mirada del oficio docente que se configura en ella y con ella, y que implica un cierto tipo de relación estudiosa y atenta con nuestra materia de enseñanza, que en esta caso se trata de la gimnasia escolar

Este artigo é elaborado no âmbito do grupo de pesquisa Ensino, Escola, Arte e Educação do Corpo (DESAREC) do Instituto Superior de Educação Física (ISEF) da Universidade da República (Udelar), Uruguai. Objetivo:Revisão de um artigo publicado em 2006 na revista Isefdigital, que tratava do problema da seleção e sequenciamento de conteúdos na educação física. Resultados e discussão:Nesta ocasião, são incorporados novos elementos que trazem em diálogo questões próprias ao desenho de sequências de ensino com alguns estudos e exercícios de pintura que, a partir dos entre-lugares com a arte, entendemos que podem contribuir para pensar a docência e o ensino desde outra perspectiva de exploração possível. A partir dessas relações, apresenta-se um exercício de sequenciamento para o caso da ginástica escolar, tentando assim esclarecer alguns problemas que a área apresenta em geral, tanto em sua conceituação quanto em seu ensino. Considerações finais: Dessa forma delineia-se uma perspectiva conceitual da escola como forma pedagógica e, portanto, sobre uma visão particular da profissão docente que se configura nela e com ela, o que implica certotipo de relação estudiosa e atenta com a nossa matéria de ensino.

This article has been prepared within the framework of the Teaching, School, Art and Education of the Body (DESAREC) research group of the Higher Institute of Physical Education (ISEF) of the University of the Republic (Udelar),Uruguay. Objetive:To elaborate a revision of an article published in 2006 in the IsefDigitalmagazine, which dealt with problematizing the selection and sequencing of content in physical education. Discussion and results:On this occasion, new elements are incorporated that put in dialogue issues related to the design of teaching sequences with some studies and painting exercises that, from the between-places with art, we understand they can contribute to consider teaching and education from another possible perspective of exploration. Based on these relationships, a sequencing exercise is presented for the case of school gymnastics, thus trying to clear up some problems that the field has in general, both in its conceptualization and in its teaching.FinalConsiderations:Following that, a conceptual perspective of school as a pedagogical form is outlined and therefore, on a particular view of the teaching profession that is configured in and with it, implying a certain type of studious and attentive relationship with our teaching subject.

El Dr. Salman visitando a su familia / Dr Salman visiting his family

Cuando el Dr. Salman me envió algunas fotos de referencia, instantáneamente supe que tenía que elegir la foto en la que se basa esta pintura; aunque era una escena compleja con varias figuras, la narrativa que presentaba era muy poderosa y emotiva. Quería evitar el sentimentalismo, y creo que la atrevida técnica del empaste que usé, con pintura al óleo espesa y un pincel grande, ayudó con esto. Se trataba principalmente de transmitir emociones crudas de una manera expresiva, sin incluir muchos detalles. Además, convertirla en una imagen fácilmente legible solo con pinceladas sueltas, sin delinear todo, fue un verdadero desafío. Espero haberlo logrado.

When Dr Salman sent me some reference photos, I instantly knew I had to choose the photo this painting is based on - although it was a complex scene with several figures, the narrative it presented was very powerful and emotional. I wanted to avoid sentimentality, and I think that the bold impasto technique I used, with thick oil paint and a large brush, helped with this. It was mostly about conveying raw emotion in an expressive way, without including lots of detail. Also making it an easily readable image just using loose brushstrokes, without delineating everything was a real challenge. I hope I succeeded. 1. Nick Richards is a London based portrait and plein air painter. He accepts portrait commissions from life or from photos. Nick paints landscapes & cityscapes directly from life in oils, on location in front of the subject as he loves the challenge of trying to capture the weather, the light and the essence of a place. Nick has exhibited with the Royal Institute of Oil Painters for the last two years, has appeared on Sky Portrait Artist of the Year & is shortlisted for the Sequested Prize.

Quando o Dr. Salman me enviou algumas fotos de referência, eu soube imediatamente que tinha que escolher a foto na qual esta pintura se baseia - embora fosse uma cena complexa com várias figuras, a narrativa que ela apresentava era muito poderosa e emocionante. Queria evitar o sentimentalismo e acho que a ousada técnica de impasto que usei, com tinta a óleo grossa e um pincel grande, ajudou nisso. Tratava-se principalmente de transmitir emoção crua de uma forma expressiva, sem incluir muitos detalhes. Também torná-la uma imagem facilmente legível apenas com pinceladas soltas, sem delinear tudo foi um verdadeiro desafio. Espero ter conseguido.

Environmentally Friendly, High-Performance Fire Retardant Made from Cellulose and Graphite.

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

Effects of substances released from a coal tar-based coating used to protect harbor structures on oysters.

Products coal tar-based are largely used as concrete structures as protective coatings but some questions about leaching and potential toxic effects remain unclear. A laboratory experiment exposing oysters to miniaturized concrete pillars painted with Lackpoxi N1761 over time was performed and trace elements and 17 PAH were monitored in seawater exposure media, and oyster tissues. The original paint composition was also analyzed, and high concentrations of trace elements and PAH were detected. Sharp increases in PAH concentrations were observed after 6-96 h in exposure media and oyster tissues, suggesting that these compounds were leached from the painted structures. In parallel, the integrity of the hemocytes lysosomal membranes of exposed organisms has been damaged. Based on the response of this biomarker, the use of Lackpoxi N1761 is potentially harmful to the environment and it is required that coal tar-based paints be evaluated according to the environmental risk assessment protocols.

Legacy and emerging antifouling biocide residues in a tropical estuarine system (Espirito Santo state, SE, Brazil).

The contamination by antifouling biocide residues (booster biocides - diuron, Irgarol, chlorothalonil, dichlofluanid and DCOIT; butyltin compounds-BTs (TBT, DBT and MBT); and antifouling paint particles-APPs) was appraised in sediments of Vitoria Estuarine System (VES). Even at its historical lower (ΣBTs ≤113 ng Sn g-1 dry wt), the current environmental levels of BTs in areas with a predominance of boatyards still pose a risk to the local biota and human population. DCOIT, among booster biocides, was the most frequently detected, especially in boatyards (≤40 ng g-1 dry wt) and Vitoria Port (64 ng g-1 dry wt), while APPs were also detected mainly in sediments of boatyards (≤5,969 µg g-1 dry wt). Since levels of diuron and DCOIT in APPs were as high as 1,670,000 and 899,000 ng g-1 dry wt, respectively, they are acting as secondary sources of these antifouling biocides. Therefore, VES is threatened by antifouling biocide residues due to the multiple diffuse sources of contamination, showing the need for more efforts on public policies (including temporal trend monitoring studies).

Labile metal assessment in water by diffusive gradients in thin films in shipyards on the Brazilian subtropical coast.

Shipyards impact on estuarine environments because of the use of antifouling paints and petroleum products, which release trace metals that may remain in their bioavailable or labile form. Regardless of its importance, the relation between continuous input of trace metals (hotspot area) and their availability in the water column has been scarcely studied. This study evaluated seasonal variations in the concentrations of labile fractions of metals in shipyards located in estuarine areas on the Brazilian subtropical coast. These fractions were determined by the Diffuse Gradients in Thin Films (DGT) technique. Maximum labile fraction concentrations of Cr (0.3 µg L-1), Ni (2.2 µg L-1) and V (2.0 µg L-1) are directly related to (i) their specific source: antifouling paints (for Cr), metal and steel alloys (for Cr and Ni) and petroleum products (for V), besides (ii) periods of intensive traffic and vessel repair. Additionally, variations in labile fractions of Ni and V in the Patos Lagoon estuary were influenced by salinity, which is known to affect metal desorption from surface sediments in resuspension events. Even though Cr is affected by the same processes, it is available as Cr(III) and does not represent any ecological risk in the study areas. Although the areas under study are affected by variations in physical and chemical conditions, shipyards were effectively hotspots of trace metals in their labile fraction in various estuarine systems in southeastern and southern Brazil. Thus, they represent areas where Ecological Risk Assessment, mainly of V, should be carried out.

Are antifouling residues a matter of concern in the largest South American port?

In the present study, levels of booster biocides (diuron, Irgarol, chlorothalonil, dichlofluanid and DCOIT), butyltin compounds (TBT, DBT and MBT) and antifouling paint particles (APPs) were assessed in sediments of areas under the influence of the largest Latin American port, marinas, boat traffic and ship/boat maintenance facilities located within Santos-São Vicente Estuarine System (SSES). Contamination profile was directly related to local maritime activities, where sediments from the main navigation channel (MNC) presented low levels of antifouling residues while adjacent areas (AA), characterized by the presence of boats and boatyards, showed higher contamination considering all analyzed residues. Moreover, areas under the influence of fishing boats/yards presented relevant levels of butyltins (ΣBTs > 300 ng g-1) and APPs (>100 µg g-1), while marinas dominated by recreational boats showed higher booster biocides occurrence. Sites located nearby shipyards in the MNC and boatyards in the AA presented expressive amounts of APPs (>200 µg g-1). These APPs represent an important long-term source of biocides to the SSES. Thus, the profile of maritime activities in association to local oceanographic conditions drive the spatial distribution of antifouling residues within SESS, which in some case presented levels above sediment guidelines for TBT, DCOIT and diuron.