Une bibliothèque numérique à l’épreuve de la déficience : études de cas

Cet article porte sur les usages possibles d’une bibliothèque numérique par des personnes présentant différentes déficiences (de nature visuelle ou motrice). Ce thème est encore insuffisamment exploré en particulier selon une approche de l’activité située des personnes dans leurs contextes singuliers. La méthode choisie est celle de l’étude de cas : les cas sont développés comme de petites histoires, non exemptes de complications, et croisés avec des fragments de récits issus de nombreux exemples. L'analyse permet peu à peu d’extraire des phénomènes prenant un statut plus générique à même d’apporter des éléments pour l’évolution du livre numérique ; ceci, tant par l’identification des obstacles dans l’usage de ressources externes que par le repérage des ressources internes développées par les sujets. Une des pistes qui ressort est l’importance de développer des systèmes techniques ouverts, capables d’accueillir la diversité des situations et des déficiences, en vue d’une conception plus orientée vers l’usage. La conclusion, qui prend une distance théorique, porte sur le pouvoir d’agir et les ressources mises en œuvre par les lecteurs pour tenter de le restaurer.This article discusses the possible uses of a digital library by people with various kinds of disability, such as visual or motor disabilities. The subject has not yet been sufficiently explored, especially using a situated action model that takes account of the specific circumstances of each person. We have approached the subject through a series of case studies. The cases are related using a short story format, without avoiding complications, and cross-referenced with fragments of accounts taken from numerous examples. This analysis allows the gradual extraction of phenomena of a more general nature which provide insights for the design of digital books, helping both to identify obstacles in the incorporation of external resources and to pinpoint internal resources developed by the persons. One idea that emerges is the importance of developing open technical systems capable of accommodating various situations and disabilities so that a more user-friendly approach to design can be taken. The conclusion, made from a more theoretical viewpoint, looks at the concept of “empowerment” (pouvoir d’agir) and the resources employed by readers in an attempt to regain it

Characterization of sediment subject or not to anthropogenic activities (Golfo Nuevo, Patagonia Argentina)

Contaminantes orgánicos como el tributilestaño (TBT) son particularmente tóxicos para la fauna marina. El objetivo de este trabajo fue caracterizar un sitio contaminado crónicamente (Muelle Luis Piedrabuena-MLP) y otro sin signos de impacto antrópico (Cerro Avanzado-CA) previo al desarrollo de un experimento para evaluar la respuesta de la comunidad macrobentónica al TBT. Para ello, se colectaron muestras de sedimento (n=3) con un corer (diámetro: 11 cm, altura: 15 cm) y se realizó la determinación de parámetros “in situ”. Los resultados indicaron mayores porcentajes de humedad y materia orgánica en MLP cerca de la superficie (46,7±4,1% y 2,8±0,2% versus 27,0±1,0% y 1,2±0,3% en profundidad, respectivamente), mientras que en CA la distribución de estos parámetros fue homogénea (28,5±1,2% y 1,5±0,1%, respectivamente). Con respecto a los análisis biológicos, la clase Polychaeta fue la más abundante en ambos sitios mientras que Anfípoda y Bivalvia predominaron en MLP y CA, respectivamente.Centro de Investigaciones Geológica

Characterization of sediment subject or not to anthropogenic activities (Golfo Nuevo, Patagonia Argentina)

Contaminantes orgánicos como el tributilestaño (TBT) son particularmente tóxicos para la fauna marina. El objetivo de este trabajo fue caracterizar un sitio contaminado crónicamente (Muelle Luis Piedrabuena-MLP) y otro sin signos de impacto antrópico (Cerro Avanzado-CA) previo al desarrollo de un experimento para evaluar la respuesta de la comunidad macrobentónica al TBT. Para ello, se colectaron muestras de sedimento (n=3) con un corer (diámetro: 11 cm, altura: 15 cm) y se realizó la determinación de parámetros “in situ”. Los resultados indicaron mayores porcentajes de humedad y materia orgánica en MLP cerca de la superficie (46,7±4,1% y 2,8±0,2% versus 27,0±1,0% y 1,2±0,3% en profundidad, respectivamente), mientras que en CA la distribución de estos parámetros fue homogénea (28,5±1,2% y 1,5±0,1%, respectivamente). Con respecto a los análisis biológicos, la clase Polychaeta fue la más abundante en ambos sitios mientras que Anfípoda y Bivalvia predominaron en MLP y CA, respectivamente.Centro de Investigaciones Geológica

Cardiac protein kinases: the cardiomyocyte kinome and differential kinase expression in human failing hearts

Aims. Protein kinases are potential therapeutic targets for heart failure, but most studies of cardiac protein kinases derive from other systems, an approach that fails to account for specific kinases expressed in the heart and the contractile cardiomyocytes. We aimed to define the cardiomyocyte kinome (i.e. the protein kinases expressed in cardiomyocytes) and identify kinases with altered expression in human failing hearts. Methods and Results. Expression profiling (Affymetrix microarrays) detected >400 protein kinase mRNAs in rat neonatal ventricular myocytes (NVMs) and/or adult ventricular myocytes (AVMs), 32 and 93 of which were significantly upregulated or downregulated (>2-fold), respectively, in AVMs. Data for AGC family members were validated by qPCR. Proteomics analysis identified >180 cardiomyocyte protein kinases, with high relative expression of mitogen-activated protein kinase cascades and other known cardiomyocyte kinases (e.g. CAMKs, cAMP-dependent protein kinase). Other kinases are poorly-investigated (e.g. Slk, Stk24, Oxsr1). Expression of Akt1/2/3, BRaf, ERK1/2, Map2k1, Map3k8, Map4k4, MST1/3, p38-MAPK, PKCδ, Pkn2, Ripk1/2, Tnni3k and Zak was confirmed by immunoblotting. Relative to total protein, Map3k8 and Tnni3k were upregulated in AVMs vs NVMs. Microarray data for human hearts demonstrated variation in kinome expression that may influence responses to kinase inhibitor therapies. Furthermore, some kinases were upregulated (e.g. NRK, JAK2, STK38L) or downregulated (e.g. MAP2K1, IRAK1, STK40) in human failing hearts. Conclusions. This characterization of the spectrum of kinases expressed in cardiomyocytes and the heart (cardiomyocyte and cardiac kinomes) identified novel kinases, some of which are differentially expressed in failing human hearts and could serve as potential therapeutic targets

Fate of petroleum hydrocarbons in bioturbated pristine sediments from Caleta Valdés (Patagonia Argentina): An ex situ bioassay

Petroleum can pollute pristine shorelines as a consequence of accidental spills or chronic leaks. In this study, the fate of petroleum hydrocarbons in soft pristine sediment of Caleta Valdés (Argentina) subject toex situsimulated oil pollution was assessed. Sedimentary columns were exposed to medium and high concentrations of Escalante Crude Oil (ECO) and incubated in the laboratory during 30 days. Levels of aliphatic hydrocarbons at different depths of the sedimentary column were determined by gas chromatography. Oil penetration was limited to the first three centimetres in both treatments, and under this depth, hydrocarbons were clearly biogenic (terrestrial plants) as in the whole sedimentary column of the control assay. Bioturbation by macrobenthic infauna was strongly impacted by oil pollution which resulted in reduced sediment oxygenation and low burial of petroleum hydrocarbons. This may partly explain the limited hydrocarbon biodegradation observed, as indicated by the relatively high values of the ratios nC17/pristane,nC18/phytane, and total resolved aliphatic hydrocarbons/ unresolved complex mixture. Correspondingly, at the end of the experiment the most probable number of hydrocarbon-degrading bacteria reached ~ 10^3 MPN g−1 dry weight. These values were lower than those found in chronically polluted coastal sediments, reflecting a low activity level of the oil-degrading community. The results highlight the low attenuation capacities of Caleta Valdés pristine sediments to recover its original characteristics in a short time period if an oil spill occurs. In this work, we present a novel and integrative tool to evaluate the fate of petroleum hydrocarbons and their potential damage on pristine sediments

Titin visualization in real time reveals an unexpected level of mobility within and between sarcomeres

Contrary to prior models in which titin serves as a stable scaffold in sarcomeres, sarcomeric and soluble titin exchange dynamically in myofibers when calcium levels are low