695 research outputs found
Measuring the diversity of the human microbiota with targeted next-generation sequencing
No full textThe human microbiota is a complex ecological community of commensal, symbiotic and pathogenic microorganisms harboured by the human body. Next-generation sequencing (NGS) technologies, in particular targeted amplicon sequencing of the 16S ribosomal RNA gene (16S-seq), are enabling the identification and quantification of human-resident microorganisms at unprecedented resolution, providing novel insights into the role of the microbiota in health and disease. Once microbial abundances are quantified through NGS data analysis, diversity indices provide valuable mathematical tools to describe the ecological complexity of a single sample or to detect species differences between samples. However, diversity is not a determined physical quantity for which a consensus definition and unit of measure have been established, and several diversity indices are currently available. Furthermore, they were originally developed for macroecology and their robustness to the possible bias introduced by sequencing has not been characterized so far. To assist the reader with the selection and interpretation of diversity measures, we review a panel of broadly used indices, describing their mathematical formulations, purposes and properties, and characterize their behaviour and criticalities in dependence of the data features using simulated data as ground truth. In addition, we make available an R package, DiversitySeq, which implements in a unified framework the full panel of diversity indices and a simulator of 16S-seq data, and thus represents a valuable resource for the analysis of diversity from NGS count data and for the benchmarking of computational methods for 16S-seq
White matter and task-switching in young adults: A Diffusion Tensor Imaging study
No full textThe capacity to flexibly switch between different task rules has been previously associated with distributed fronto-parietal networks, predominantly in the left hemisphere for phasic switching sub-processes, and in the right hemisphere for more tonic aspects of task-switching, such as rule maintenance and management. It is thus likely that the white matter (WM) connectivity between these regions is critical in sustaining the flexibility required by task-switching. This study examined the relationship between WM microstructure in young adults and task-switching performance in different paradigms: classical shape-color, spatial and grammatical tasks. The main results showed an association between WM integrity in anterior portions of the corpus callosum (genu and body) and a sustained measure of task-switching performance. In particular, a higher fractional anisotropy and a lower radial diffusivity in these WM regions were associated with smaller mixing costs both in the spatial task-switching paradigm and in the shape-color one, as confirmed by a conjunction analysis. No association was found with behavioral measures obtained in the grammatical task-switching paradigm. The switch costs, a measure of phasic switching processes, were not correlated with WM microstructure in any task. This study shows that a more efficient inter-hemispheric connectivity within the frontal lobes favors sustained task-switching processes, especially with task contexts embedding non-verbal components
The neural substrate of spatial memory stabilization depends on the distribution of the training sessions
No full textDistributed training is known to lead to more robust memory formation as compared to training experiences with short intervals. Although this phenomenon, termed distributed practice effect, ubiquitous over a wide variety of tasks and organisms, has long been known by psychologists, its neurobiological underpinning is still poorly understood. Using the striatum as a model system here we tested the hypothesis that the ability of distributed training to optimize memory might depend upon the recruitment of different neural substrates compared to those engaged by massed training. First, by contrasting the medial and the lateral domains of the dorsal striatum after massed and distributed training we demonstrated that neuronal activity, as assessed using c-Fos expression, is differentially affected by the training protocol in the two striatal subregions. Next, by blocking the AMPA receptors before recall we provide evidence to support a selective role of the medial and the lateral striatum in the storage of information acquired respectively by massed and distributed training. Finally, we found that optogenetic stimulation of the dorsolateral striatum during massed training enables the formation of an enduring memory similarly to what is observed with distributed learning. Overall, these findings identify a possible mechanism for the distributed practice effect, a still poorly understood aspect of learning
“but I am also influenced by no such thing”-The Radical Pietist and Theological Author Johanna Eleonora Petersen
No full textJohanna Eleonora von und zu Merlau, verheiratete Petersen, von jeher tief gläubig, veränderte die religiöse Welt des 17. Jahrhunderts. Sie bekannte sich zur Bewegung des Pietismus und vertrat radikale Ansichten, nicht nur im privaten Kreis, sondern als anerkannte und heftig kritisierte theologische Autorin. Ihrem Werk ist eine Studie gewidmet, in der neue Forschungsergebnisse vorgestellt und Leben und Werk dieser bedeutenden Autorin in zeitgenössische Diskurse eingebunden werden.The deeply devout Johanna Eleonora Petersen, whose maiden name was „von und zu Merlau,” changed the religious world of the seventeenth century. She avowed herself to Pietism and held radical views, not only in private but also as an acknowledged and sharply criticized theological author. This study attends to her work. It presents new research results and weaves the life and work of this important author into contemporary discourses
La notion de défectuosité du produit dans les jurisprudences des pays européens
No full textThis work analyses the notion of defective product originally developed by US Courts, then ambiguously defined by the European directive n. 374 of 1985 and differently interpreted and applied by the respective domestic Courts. In particular, some European jurisdictions apply the risk / utility test introduced by the US Courts for design defects cases, although this test is not mentioned by the European Directive. The author, having highlighted the inconsistences of the risk / utility test, proposes an alternative model of classification of defective products according to the elements actually used by judges in order to allocate the liability, as emerging from the text of their decisions. This classification leads to held the manufacturer strictly liable not only for manufacturing defects, but also for those design defects which he was aware of (as in some cases of defective vaccine).Cette étude examine la notion de défectuosité du produit initialement élaborée par les Cours américaines, définie de manière ambigüe par le législateur européen avec la directive n° 374 de 1985, puis différemment interprétée et appliquée par les Cours respectives des pays membres. Notamment certains systèmes juridiques européens appliquent le risk/ utility test élaboré par les Cours américaines pour les cas de défaut de conception du produit, bien que ce test ne soit pas mentionné par la directive européenne. L’auteur, après avoir mis en évidence les incongruences du risk/ utility test, propose un modèle alternatif de classification des cas de produits défectueux sur la base des critères d’imputation de la responsabilité qui sont concrètement utilisés par les juges et tels qu’imagés dans les textes de leurs décisions. Cette reconstruction amène à imputer au fabricant une responsabilité objective non seulement pour les cas de défaut de production, mais aussi pour les cas de défaut de conception dont il était averti (tel que certain cas de vaccin défectueux).Rajneri Karageorgevitch Eleonora. La notion de défectuosité du produit dans les jurisprudences des pays européens. In: Revue internationale de droit comparé. Vol. 67 N°1,2015. pp. 185-205
TO THE JUBILEE OF PROFESSOR STEPANOVA ELEONORA FEDOROVNA
No full textThe article is devoted to the anniversary of Professor Eleonora Fedorovna Stepanova – a bright representative of the Russian intelligentsia: a talented lecturer, an inventor, an author of numerous books, an internationally recognized scholar
Author response
No full textHebb's idea of a cell assembly as the fundamental unit of neural information processing has dominated neuroscience like no other theoretical concept within the past 60 years. A range of different physiological phenomena, from precisely synchronized spiking to broadly simultaneous rate increases, has been subsumed under this term. Yet progress in this area is hampered by the lack of statistical tools that would enable to extract assemblies with arbitrary constellations of time lags, and at multiple temporal scales, partly due to the severe computational burden. Here we present such a unifying methodological and conceptual framework which detects assembly structure at many different time scales, levels of precision, and with arbitrary internal organization. Applying this methodology to multiple single unit recordings from various cortical areas, we find that there is no universal cortical coding scheme, but that assembly structure and precision significantly depends on the brain area recorded and ongoing task demands
Rescate y conservación del Acervo Histórico del Palacio de Minería: Informe de las labores de conservación preventiva e intervenciones menores en material Bibliohemerográfico y actividades en apoyo al Acervo Histórico : octubre 2011 - febrero 2012
No full textEl presente informe tiene como finalidad dar constancia de los trabajos realizados en el Acervo Histórico del Palacio de Minería, por los restauradores Roderick Palacios, Isabel Ritter y Eleonora Cruz, pasantes de la Licenciatura en Restauración de Bienes Culturales como prestación de su servicio social.</p
Tra quadro e cornice
No full textThe author presents a reconstruction of the experience she had in Pontedera when she saw some performances of the Workcenter of Jerzy Grotowski and Thomas Richards and took part to some works of the group. The text is composed by two parts: a descriptive and a theoretical one. In the first part, that she called “paintings”, the author tries to present his memory of what she saw and of what happened. Two plays are described, namely L’heure fugitive and The Underground, from the Focused Research Team in Art as a Vehicle, directed by Thomas Richards. After that, there is a description of open rehearsal of Thomas Richards’ group, in which the actors did singing exercises. The last activity was instead a singing session with Mario Biagini and his team, where the author and her colleagues participated actively. In the theoretical part, the author exposes her reflections concerning performances and other experiences, by focusing in particular on their meaning as well as on their major points of interest
Tra quadro e cornice. Resoconto di un viaggio a Vallicelle
No full textThe author presents a reconstruction of the experience she had in Pontedera when she saw some performances of the Workcenter of Jerzy Grotowski and Thomas Richards and took part to some works of the group. The text is composed by two parts: a descriptive and a theoretical one. In the first part, that she called “paintings”, the author tries to present his memory of what she saw and of what happened. Two plays are described, namely L’heure fugitive and The Underground, from the Focused Research Team in Art as a Vehicle, directed by Thomas Richards. After that, there is a description of open rehearsal of Thomas Richards’ group, in which the actors did singing exercises. The last activity was instead a singing session with Mario Biagini and his team, where the author and her colleagues participated actively. In the theoretical part, the author exposes her reflections concerning performances and other experiences, by focusing in particular on their meaning as well as on their major points of interest
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