Speech and music are two distinct activities, yet in songs they are joined. To understand this, two questions need to be answered. How are speech and music different? The differences between speech ...and music are crucial for the existence of songs. Because speech and music give primary importance to different phonetic qualities, they can co-exist within a single sound signal. This makes it possible for a single person to produce simultaneously speech and music: to sing. Speech and music also differ in how information is encoded within the sound signal. Speech encodes information very efficiently, while music is a better artistic medium, since it contains greater contrasts. Because the brain processes speech separately from music, a listener can enjoy both simultaneously--that is, the listener can enjoy a song. How are speech and music alike? Rhythmic information is decoded according to similar principles in both speech and music. As a result, there is no such thing as "speech-accentuation" versus "music-accentuation". There is only "accentuation". This means that the association of speech and music is rhythmically constrained. One constraint limits the association of boundaries, and the other constraint restricts the association of unaccented elements. These two constraints are asymmetric, placing constraints on the music (relative to the lyrics) rather than on the lyrics (relative to the music). Having gained an understanding of songs, it is now possible to ask: What can songs tell us about language? A study of misaccentuations in songs reveals that there is a gradient in the speech grid. Elements low on the grid are most important, so misaccentuations involving these elements are most strongly avoided. Misaccentuations involving elements higher on the grid are tolerated. A statistical analysis of misaccentuations reveals the number of gridmarks received by various syllables. That is, it reveals whether they receive one, two or at least three marks on a Selkirk (1984) type grid. This type of analysis, applied to English and French, clearly reveals the prosodic difference between the two languages: 'stress-timed' English shows strong contrasts on the gradient grid, while 'syllable-timed' French does not.
Une méta-analyse portant sur l'évaluation de l'effet de l'information détaillée sur l'anxiété des patients durant la période préopératoire a été réalisée à partir d'un ensemble final de six études. ...Les études ont été publiées entre janvier 1974 et février 1996. Les études ont été répertoriées à partir de Medline, du Cumulated Index Medicus, et également après vérification de la bibliographie d'articles pertinents. Dans ces publications, nous devions retrouver une évaluation de l'effet psychologique d'une information détaillée sur l'anxiété présenté lors de la période préopératoire. Cette information pouvait être réalisée par un personnel qualifié, un livret, une cassette audio ou une vidéocassette. Une évaluation qualitative des articles a été réalisée. Pour cela les articles devaient renfermer un groupe expérimental et un groupe témoin. Toutes les informations nécessaires à la réalisation de la méta-analyse, de même que l'évaluation de leur rigueur scientifique ont été colligés par une même personne. Des mesures ont été prises afin de contrôler la possibilité du biais de l'observateur. L'évaluation du protocole d'étude, de même que celle des analyses statistiques et la présentation des résultats ont été faites à partir de la grille de Chalmers traduite et adaptée à l'étude. Résumé abrégé par UMI
Oxazolidinones are a class of synthetic antimicrobial agents with potent activity against a wide range of multidrug-resistant Gram-positive pathogens including methicillin-resistant Staphylococcus ...aureus and vancomycin-resistant enterococci. Oxazolidinones exhibit their antibacterial effects by inhibiting protein synthesis acting on the ribosomal 50S subunit of the bacteria and thus preventing formation of a functional 70S initiation complex. Currently, two oxazolidinones have been approved by the US Food and Drug Administration: linezolid and more recently tedizolid. Other oxazolidinones are currently under investigation in clinical trials. These antimicrobial agents exhibit a favourable pharmacokinetic profile with an excellent bioavailability and a good tissue and organ penetration. In-vitro susceptibility studies have shown that oxazolidinones are bacteriostatic against enterococci and staphylococci, and bactericidal for the majority of strains of streptococci. In the context of emergence of resistance to glycopeptides, oxazolidinones have become an effective alternative to vancomycin treatment frequently associated with nephrotoxicity. However, oxazolidinones, and linezolid in particular, are associated with significant adverse events, myelosuppression representing the main unfavourable side effect. More recently, tedizolid has been shown to effectively treat acute bacterial skin and skin structure infections. This newer oxazolidinone offers the advantages of once-daily dosing and a better safety profile in healthy volunteer studies (fewer gastrointestinal and haematological side effects). The potential use of tedizolid for other infections that could require longer therapy warrants further studies for positioning this new oxazolidinone in the available antimicrobial armamentarium. Moreover, other oxazolidinones are currently under active investigation.
Individual reactions to traumatic stress vary dramatically, yet the biological basis of this variation remains poorly understood. Recent studies demonstrate the surprising plasticity of ...oligodendrocytes and myelin with stress and experience, providing a potential mechanism by which trauma induces aberrant structural and functional changes in the adult brain. In this study, we utilized a translational approach to test the hypothesis that gray matter oligodendrocytes contribute to traumatic-stress-induced behavioral variation in both rats and humans. We exposed adult, male rats to a single, severe stressor and used a multimodal approach to characterize avoidance, startle, and fear-learning behavior, as well as oligodendrocyte and myelin basic protein (MBP) content in multiple brain areas. We found that oligodendrocyte cell density and MBP were correlated with behavioral outcomes in a region-specific manner. Specifically, stress-induced avoidance positively correlated with hippocampal dentate gyrus oligodendrocytes and MBP. Viral overexpression of the oligodendrogenic factor Olig1 in the dentate gyrus was sufficient to induce an anxiety-like behavioral phenotype. In contrast, contextual fear learning positively correlated with MBP in the amygdala and spatial-processing regions of the hippocampus. In a group of trauma-exposed US veterans, T1-/T2-weighted magnetic resonance imaging estimates of hippocampal and amygdala myelin associated with symptom profiles in a region-specific manner that mirrored the findings in rats. These results demonstrate a species-independent relationship between region-specific, gray matter oligodendrocytes and differential behavioral phenotypes following traumatic stress exposure. This study suggests a novel mechanism for brain plasticity that underlies individual variance in sensitivity to traumatic stress.
The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, plant growth-promoting ...rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and development of root hairs. PGPR also modify root functioning, improve plant nutrition and influence the physiology of the whole plant. Recent results provided first clues as to how PGPR signals could trigger these plant responses. Whether local and/or systemic, the plant molecular pathways involved remain often unknown. From an ecological point of view, it emerged that PGPR form coherent functional groups, whose rhizosphere ecology is influenced by a myriad of abiotic and biotic factors in natural and agricultural soils, and these factors can in turn modulate PGPR effects on roots. In this paper, we address novel knowledge and gaps on PGPR modes of action and signals, and highlight recent progress on the links between plant morphological and physiological effects induced by PGPR. We also show the importance of taking into account the size, diversity, and gene expression patterns of PGPR assemblages in the rhizosphere to better understand their impact on plant growth and functioning. Integrating mechanistic and ecological knowledge on PGPR populations in soil will be a prerequisite to develop novel management strategies for sustainable agriculture.
The positive effects of root-colonizing bacteria cooperating with plants lead to improved growth and/or health of their eukaryotic hosts. Some of these Plant Growth-Promoting Rhizobacteria (PGPR) ...display several plant-beneficial properties, suggesting that the accumulation of the corresponding genes could have been selected in these bacteria. Here, this issue was targeted using 23 genes contributing directly or indirectly to established PGPR effects, based on genome sequence analysis of 304 contrasted Alpha- Beta- and Gammaproteobacteria. Most of the 23 genes studied were also found in non-PGPR Proteobacteria and none of them were common to all 25 PGPR genomes studied. However, ancestral character reconstruction indicated that gene transfers -predominantly ancient- resulted in characteristic gene combinations according to taxonomic subgroups of PGPR strains. This suggests that the PGPR-plant cooperation could have established separately in various taxa, yielding PGPR strains that use different gene assortments. The number of genes contributing to plant-beneficial functions increased along the continuum -animal pathogens, phytopathogens, saprophytes, endophytes/symbionts, PGPR- indicating that the accumulation of these genes (and possibly of different plant-beneficial traits) might be an intrinsic PGPR feature. This work uncovered preferential associations occurring between certain genes contributing to phytobeneficial traits and provides new insights into the emergence of PGPR bacteria.
Central venous catheterization (CVC) is a frequent procedure, practiced by intensivists, anesthesiologists and advanced practice nurses in intensive care units and operative rooms. To reduce ...CVC-associated morbidity, it is essential to strive for best practices, based on the latest evidence. This narrative review aims to synthesize current knowledge on evidence-based best practices for CVC that improve the use and feasibility of real-time ultrasound-guided insertion procedures. Optimization of the vein puncture technique and the development of new technologies are discussed to reinforce the use of the subclavian vein catheterization as first choice. The search for alternative site of insertions, without increasing infectious and thrombotic risks, deserves further research.
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