10,047 research outputs found
Information flow through a model of the C. elegans klinotaxis circuit
Understanding how information about external stimuli is transformed into
behavior is one of the central goals of neuroscience. Here we characterize the
information flow through a complete sensorimotor circuit: from stimulus, to
sensory neurons, to interneurons, to motor neurons, to muscles, to motion.
Specifically, we apply a recently developed framework for quantifying
information flow to a previously published ensemble of models of salt
klinotaxis in the nematode worm C. elegans. The models are grounded in the
neuroanatomy and currently known neurophysiology of the worm. The unknown model
parameters were optimized to reproduce the worm's behavior. Information flow
analysis reveals several key principles underlying how the models operate: (1)
Interneuron class AIY is responsible for integrating information about positive
and negative changes in concentration, and exhibits a strong left/right
information asymmetry. (2) Gap junctions play a crucial role in the transfer of
information responsible for the information symmetry observed in interneuron
class AIZ. (3) Neck motor neuron class SMB implements an information gating
mechanism that underlies the circuit's state-dependent response. (4) The neck
carries non-uniform distribution about changes in concentration. Thus, not all
directions of movement are equally informative. Each of these findings
corresponds to an experimental prediction that could be tested in the worm to
greatly refine our understanding of the neural circuit underlying klinotaxis.
Information flow analysis also allows us to explore how information flow
relates to underlying electrophysiology. Despite large variations in the neural
parameters of individual circuits, the overall information flow architecture
circuit is remarkably consistent across the ensemble, suggesting that
information flow analysis captures general principles of operation for the
klinotaxis circuit
Complications aprÚs hystérectomie pour cancers gynécologiques : Laparoscopie vs Laparotomie.
Objectif : Comparer les hystérectomies réalisées par laparoscopie à celles
accomplies par laparotomie pour des pathologies gynécologiques malignes.
Méthode : Etude basée sur 169 hystérectomies effectuées pour cancer de l'endomÚtre, du col ou de l'ovaire, pratiquées dans le service de gynécologie de la Maternité du CHUV de janvier 2002 à décembre 2009 sur des femmes ùgées de 28 à 91 ans. Le but est de comparer deux différentes voies d'abord chirurgicales qui sont la laparotomie et la laparoscopie en terme de durée d'hospitalisation, d'indications, de complications per et post opératoires mineures et majeures et de nécessité de reprise ou d'une ré-hospitalisation.
Résultats: Cette étude compte 169 patientes, dont 126 hystérectomies réalisées par laparotomie et 43 accomplies par laparoscopie. Les deux groupes sont similaires en terme d'ùge (ùge moyen : 63ans), d'indice de masse corporelle (26 vs 25) et de parité (1.5 enfants). Le temps opératoire est semblable entre les deux groupes (211 vs 219 minutes). Des hémorragies (pertes sanguines de plus de 1000ml) surviennent dans 24.6% des hystérectomies par laparotomie et dans 11.63% des hystérectomies par laparoscopie. Il existe une différence statistiquement significative entre la nécessité d'une transfusion peropératoire et les deux différentes voie d'abord (p=0.045). Une transfusion peropératoire a été nécessaire dans 13.22% des laparotomies contre seulement 2.33% des laparoscopies. La durée d'hospitalisation est significativement plus longue pour les patientes ayant subi une hystérectomie par laparotomie (12 vs 6 jours; p<0.001). Les complications peropératoires et postopératoires mineures dépendent de maniÚre significative de la voie d'abord (p=0.01 ; p= 0.025). On observe des complications peropératoires dans 31.75% des laparotomies et dans 11.63% des laparoscopies. Les complications postopératoires mineures sont observées dans 28.57% des laparotomies et dans 11.63% des laparoscopies. Dans 7.14% des laparotomies on observe une complications postopératoire majeure et aucune de sont apparues lors d'hystérectomie par laparoscopie. La nécessité de reprise, de ré-opération ou de ré-hospitalisation n'est statistiquement pas différente entre la laparoscopie et la laparotomie.
Conclusion : On observe un avantage significatif en faveur de l'hystérectomie par laparoscopie avec une réduction de la durée d'hospitalisation, ainsi que des complications peropératoires et postopératoires mineures et majeures, moins importantes
Names of fungal species with the same epithet applied to different morphs: how to treat them
The abolition of the separate naming of different morphs of the same fungal species in 2011 will inevitably result in many name changes in some genera. The working practices commended here are intended to minimize one category of these changes, that which can arise as a consequence of an author using the epithet of an asexual morph when describing the sexual morph of the same species. We consider that name proposed for the sexual morph in such cases should be treated as a formal error for a new combination and not as a new species, and so be corrected. This is interpreted as applying even where the author indicated that a new species was being described and designated a type. We argue that those formalities were a result of the requirements of the rules then in force, as the author recognized that a morph of a named species was being described, and not a new hitherto unnamed species was being reported - but was barred from making a new combination so used the same epithet for the new morph name instead. Where a type with the sexual morph was designated for the sexual morph, under this interpretation that no longer has nomenclatural status, the type being that of the basionym. The material for the sexual morph indicated as a type, would be available for designation as an epitype, though a modern sequenced sample with both sexual and asexual morphs would be more informative as an epitype in many cases. A proposal to regularize the working practice commended here, and also the converse situation where the sexual morph typified name is the earlier, will be made to the 2017 Shenzhen Congress
The Constitution of Japan, at the Founding and 50 Years Later
This is a revised version of a paper presented by Professor Beer at a combined meeting of the New Zealand Institute of Public Law and of the New Zealand Association for Comparative Law in the Faculty of Law, Victoria University of Wellington, New Zealand in August 1996. The author explores constitutional issues in Japan after WWII. As the world's prime example of successful synthesis of radically different traditions of law and constitution, the author concludes that Japan deserves global respect and more study in the emerging multi-cultural age
Multinational lessons from local and regional economic development agencies
This paper discusses the commonalities and differences in local and regional economic development (LRED) across England, Northern Ireland, Australia and the US. The focus is on four themes: the institutional characteristics of the respondents; governance, partners and partnerships; the objectives, regional capacity building and business service activities of responding agencies; and the self-assessment of effectiveness by LRED organisations. Our analysis is based on a survey of LRED agencies in the above-noted countries using a common questionnaire that was slightly adapted for each study area. Using logistic regression, we identify the practices and strategies of local and regional economic development agencies that are associated with higher levels of effectiveness. When all participating nationsâ LRED organisations are jointly evaluated, several practices emerge as being positively related to agency performance including being actively involved in industrial estates, labour training and recruitment, marketing the agencyâs region to international markets, and promoting industry clusters. Also showing as being positively related to performance are variables identifying whether or not the agency subsidized relocation costs for new businesses, helps local companies access venture capital, engages in education and training programs targeted at youths, and enhances networking opportunities for local business people. Interestingly, we found statistically significant negative relationships between agency effectiveness and engaging in tourism promotion activities, training minority groups, and conducting target industry studies, though this may reflect a correlation between certain activities and problematic economic environments. Though our research methodology of relying on self-assessed performance measures does not allow us to draw sweeping conclusions, we are confident that these findings provide a beginning for identifying a set of best practices that are appropriate for LRED organisations in a multinational setting.
Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy
We studied the interaction between phototrophic and chemolithoautotrophic sulphide-oxidizing microorganisms in natural microbial mats forming in sulphidic streams. The structure of these mats varied between two end-members: one characterized by a layer dominated by large sulphur-oxidizing bacteria (SOB; mostly Beggiatoa-like) on top of a cyanobacterial layer (B/C mats) and the other with an inverted structure (C/B mats). C/B mats formed where the availability of oxygen from the water column was limited (<5 mu M). Aerobic chemolithotrophic activity of the SOB depended entirely on oxygen produced locally by cyanobacteria during high light conditions. In contrast, B/C mats formed at locations where oxygen in the water column was comparatively abundant (445 mu M) and continuously present. Here SOB were independent of the photosynthetic activity of cyanobacteria and outcompeted the cyanobacteria in the uppermost layer of the mat where energy sources for both functional groups were concentrated. Outcompetition of photosynthetic microbes in the presence of light was facilitated by the decoupling of aerobic chemolithotrophy and oxygenic phototrophy. Remarkably, the B/C mats conserved much less energy than the C/B mats, although similar amounts of light and chemical energy were available. Thus ecosystems do not necessarily develop towards optimal energy usage. Our data suggest that, when two independent sources of energy are available, the structure and activity of microbial communities is primarily determined by the continuous rather than the intermittent energy source, even if the time-integrated energy flux of the intermittent energy source is greater
Continuous twin screw granulation of controlled release formulations with various HPMC grades
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