Terrestrial nematodes from the Galapagos Archipelago : 7. Description of Tylocephalus nimius sp. n. and new data on the morphology, development and behaviour of T. auriculatus (Bütschli, 1873) Anderson, 1966 (Leptolaimina : Plectidae)

Description est donnée de #Tylocephalus nimius sp. n., provenant des îles de Santa Cruz et Floreana, caractérisé par des "cornes" mesurant 12-14 micromètres et des expansions céphaliques dépassant considérablement les soies somatiques les plus antérieures. #T. auriculatus est redécrit sur des spécimens provenant d'échantillons de sol et d'un élevage dérivé sur plaque d'agar. Pendant la prise de nourriture de #T. auriculatus, la région labiale se balance dans le plan dorso-ventral dans un mouvement oscillant, continu et indépendant de la locomotion du corps. L'hypothèse est formulée que cette espèce et les autres #Wilsonematinae se sont spécialisés à balayer les bactéries collées aux surfaces planes des éléments microscopiques du sol. De plus, les observations morphologiques et ontogéniques suggèrent que cette espèce ne passe que par trois stades juvéniles, avec une métamorphose marquée de la région labiale pendant les première et deuxième mues. (Résumé d'auteur

Terrestrial nematodes of the Galapagos archipelago : 6. Punchaulus gemellensis, a new genus and species of Aphelenchina (Tylenchida)

#Punchaulus gemellensis$ n. gen., n. sp. provenant de Los Gemelos, Ile de Santa Cruz, Galapagos, Equateur, est décrit. Il est caractérisé par un corps court et trapu (L = 300-404 micromètres; a = 14-19), un pore excréteur large et localisé au niveau de la base du procorpus, un bulbe médian presque sphérique, un isthme non musculeux long de 19-22 micromètres, un système reproducteur femelle monodelphe sans sac postvulvaire, des spicules à rostre prononcé et à limbe ventral plus long que le limbe dorsal, une queue conique à terminus tronqué et finement fimbrié. (Résumé d'auteur

Quantum-state input-output relations for absorbing cavities

The quantized electromagnetic field inside and outside an absorbing high-$Q$ cavity is studied, with special emphasis on the absorption losses in the coupling mirror and their influence on the outgoing field. Generalized operator input-output relations are derived, which are used to calculate the Wigner function of the outgoing field. To illustrate the theory, the preparation of the outgoing field in a Schr\"{o}dinger cat-like state is discussed.Comment: 12 pages, 5 eps figure

Primary Cilia are Sensory Hubs for Nitric Oxide Signaling

Primary cilia are sensory organelles present on the surface of most polarized cells. Primary cilia have been demonstrated to play many sensory cell roles, including mechanosensory and chemosensory functions. We demonstrated previously that primary cilia of vascular endothelial cells will bend in response to fluid shear stress, which leads to the biochemical production and release of nitric oxide. This process is impaired in endothelial cells that lack primary cilia function or structure. In this chapter, we will provide an overview of ciliogenesis and the differences between primary cilia and multicilia, as well as an overview of our published work on primary cilia and nitric oxide, and a brief perspective on their implications in health and disease

How learning to abstract shapes neural sound representations

The transformation of acoustic signals into abstract perceptual representations is the essence of the efficient and goal-directed neural processing of sounds in complex natural environments. While the human and animal auditory system is perfectly equipped to process the spectrotemporal sound features, adequate sound identification and categorization require neural sound representations that are invariant to irrelevant stimulus parameters. Crucially, what is relevant and irrelevant is not necessarily intrinsic to the physical stimulus structure but needs to be learned over time, often through integration of information from other senses. This review discusses the main principles underlying categorical sound perception with a special focus on the role of learning and neural plasticity. We examine the role of different neural structures along the auditory processing pathway in the formation of abstract sound representations with respect to hierarchical as well as dynamic and distributed processing models. Whereas most fMRI studies on categorical sound processing employed speech sounds, the emphasis of the current review lies on the contribution of empirical studies using natural or artificial sounds that enable separating acoustic and perceptual processing levels and avoid interference with existing category representations. Finally, we discuss the opportunities of modern analyses techniques such as multivariate pattern analysis (MVPA) in studying categorical sound representations. With their increased sensitivity to distributed activation changes—even in absence of changes in overall signal level—these analyses techniques provide a promising tool to reveal the neural underpinnings of perceptually invariant sound representations

Terrestrial nematodes of the Galapagos archipelago : 3. Aenigmenchu floreanae gen. n., sp. n., a puzzling new secernentean (Diplogasterida : Tylopharyngidae ?)

Description est donnée d'#Aenigmenchus floreanae gen. n., sp. n., provenant de l'île de Floreana, Galapagos, Equateur. Il est apparemment proche de #Tylopharynx, mais en diffère par un "stylet" minuscule (2,5-3,5 um), un pharynx très mince, une branche génitale femelle postérieure rudimentaire et la présence de quatre papilles génitales seulement chez le mâle. La forme générale et les proportions du corps ressemblent à celles des Tylenchidae, tandis que les spicules rappellent ceux des Cephalobidae. L'ouverture de l'amphide consiste en un pore minuscule et le "stylet" est si petit que sa structure exacte demeure incertaine. (Résumé d'auteur

Three teratocephalid nematodes from Iran

Trois espèces de Tératocephalides, #Teratocephalus lirellus, #Euteratocephalus palustris et #Metateratocephalus crassidens ont été récoltées dans la rhizosphère de plantes sauvages et cultivées dans la Province d'Hamadan dans l'Ouest de l'Iran. Deux populations iraniennes de #T. lirellus sont comparées avec une population belge en culture. L'étude de ces espèces en microscopie photonique et électronique a produit de nouvelles informations intéressantes. Des photos en microscopie électronique à balayage de zones fracturées de la cuticule d'#E. palustris ont montré des structures intracuticulaires plus ou moins en forme de fleur, structures qui ressemblent à celles identifiées chez #Achromadora micoletzkyi et #A. semiarmata. #Euteratocephalus spiraloides est synonymisé avec #E. palustris$. Ces espèces sont identifiées pour la première fois en Iran. (Résumé d'auteur

Expression profiling of snoRNAs in normal hematopoiesis and AML

Key Points A subset of snoRNAs is expressed in a developmental- and lineage-specific manner during human hematopoiesis. Neither host gene expression nor alternative splicing accounted for the observed differential expression of snoRNAs in a subset of AML.</jats:p

Developmental refinement of cortical systems for speech and voice processing

Development typically leads to optimized and adaptive neural mechanisms for the processing of voice and speech. In this fMRI study we investigated how this adaptive processing reaches its mature efficiency by examining the effects of task, age and phonological skills on cortical responses to voice and speech in children (8-9years), adolescents (14-15years) and adults. Participants listened to vowels (/a/, /i/, /u/) spoken by different speakers (boy, girl, man) and performed delayed-match-to-sample tasks on vowel and speaker identity. Across age groups, similar behavioral accuracy and comparable sound evoked auditory cortical fMRI responses were observed. Analysis of task-related modulations indicated a developmental enhancement of responses in the (right) superior temporal cortex during the processing of speaker information. This effect was most evident through an analysis based on individually determined voice sensitive regions. Analysis of age effects indicated that the recruitment of regions in the temporal-parietal cortex and posterior cingulate/cingulate gyrus decreased with development. Beyond age-related changes, the strength of speech-evoked activity in left posterior and right middle superior temporal regions significantly scaled with individual differences in phonological skills. Together, these findings suggest a prolonged development of the cortical functional network for speech and voice processing. This development includes a progressive refinement of the neural mechanisms for the selection and analysis of auditory information relevant to the ongoing behavioral task