Корекція якості систем стабілізації

Considered the methods of determining the desired frequency characteristics of the stabilizationsystems of the inertial control objects while the synthesis of their corrective devicesРассмотрены способы определения желаемых частотных характеристик систем стабилизации инерционныхобъектов управления при синтезе их корректирующих устройствРозглянуто способи визначення бажаних частотних характеристик систем стабілізації інерційних об’єктів керування під час синтезу їх коригувальних пристрої

Dynamics of a tunable superfluid junction

We study the population dynamics of a Bose-Einstein condensate in a double-well potential throughout the crossover from Josephson dynamics to hydrodynamics. At barriers higher than the chemical potential, we observe slow oscillations well described by a Josephson model. In the limit of low barriers, the fundamental frequency agrees with a simple hydrodynamic model, but we also observe a second, higher frequency. A full numerical simulation of the Gross-Pitaevskii equation giving the frequencies and amplitudes of the observed modes between these two limits is compared to the data and is used to understand the origin of the higher mode. Implications for trapped matter-wave interferometers are discussed.Comment: 8 pages, 7 figures; v3: Journal reference added, minor changes to tex

Application des connaissances scientifiques en prévention du suicide : Vérification d’une stratégie fondée sur la communauté de pratique

Cet article a pour objectif de décrire une expérience pilote fondée sur les principes d’action des communautés de pratique (CoP), afin de rapprocher chercheurs et milieux de pratique en prévention du suicide et favoriser une meilleure utilisation des connaissances scientifiques. Des professionnels (n = 15) de différents organismes concernés par la prévention du suicide au Québec et disséminés sur tout le territoire (Centres de prévention du suicide, centres jeunesse, direction de santé publique, milieux hospitaliers), ainsi que des chercheurs (n = 4) et un animateur de la communauté ont participé à cette expérience innovante. La CoP a permis d’obtenir des effets sur la réceptivité envers les connaissances, l’accès aux ressources et aux connaissances et le développement de collaboration entre les membres. Des conditions préalables semblent cependant nécessaires à des collaborations accrues entre recherche et pratique, notamment un rapprochement sur le plan des valeurs et une relation fondée sur la confiance et le respect de l’autre et la capacité d’investir du temps dans le développement de relations de travail.The objective of this article is to describe a pilot experiment based on community of practice (CoP) action principles and aimed at bridging the gap between suicide prevention researchers and practitioners and encouraging better utilization of research knowledge. Participants in this innovative experiment included professionals (n = 15) from a variety of Quebec organizations concerned with suicide prevention located throughout the province (suicide prevention centers, youth centers, public health department, hospital settings), researchers (n = 4) and one community animator. The CoP made it possible to obtain effects on receptivity to knowledge, access to resources and knowledge, and the development of collaboration between members. However, it would appear that certain preconditions are necessary for increased collaboration between researchers and practitioners, notably the development of greater common ground in terms of values and a relationship based on trust and mutual respect and the ability to invest time in the development of work relations

Expanding the Reach of Extension Through Social Media

With increasing numbers of the public using social media applications, Extension professionals have the ability to apply these same tools to connect with their clients. This article demonstrates how a social media toolset can be employed by Extension professionals by identifying how Extension professionals are currently using social media, illustrating how social media can be integrated into outreach and measured, and describing opportunities and challenges for Extension professionals enhancing their work with social media. With this information, Extension professionals will be better prepared to expand their outreach efforts using social media

Caractérisation d'une insertion CG dans le gène du collagène VII chez un patient atteint d'épidermolyse bulleuse dystrophique récessive de Hallopeau-Siemens

L'épidermolyse bulleuse dystrophique récessive généralisée mutilante de Hallopeau-Siemens (EBDR-HS) est une génodermatose grave, caractérisée par une fragilité cutanéo-muqueuse extrême associée à une forte diminution, voire une absence des fibres d'ancrage essentiellement constituées de collagène VIL Une liaison génétique a été établie entre le gène du collagène VII et le phénotype de l'EBDR-HS. Au cours de ce travail, on a caractérisé, à l'aide des techniques de DGGE et de séquençage d'ADN, une insertion d'un doublet CG chez un patient atteint d'EBDRHS. Cette insertion conduit à un décalage du cadre de lecture et à la création d'un codon stop précoce prédisant la synthèse de collagène VII dépourvu de 76 % de la protéine totale. Ces résultats suggèrent fortement que cette mutation, identifiée dans le gène du collagène VII est responsable des anomalies des fibres d'ancrage chez le patient étudié. De plus ils sont très utiles au conseil génétique et au diagnostic prénatal

Liquid Crystal-Solid Interface Structure at the Antiferroelectric-Ferroelectric Phase Transition

Total Internal Reflection (TIR) is used to probe the molecular organization at the surface of a tilted chiral smectic liquid crystal at temperatures in the vicinity of the bulk antiferroelectric-ferroelectric phase transition. Data are interpreted using an exact analytical solution of a real model for ferroelectric order at the surface. In the mixture T3, ferroelectric surface order is expelled with the bulk ferroelectric-antiferroelectric transition. The conditions for ferroelectric order at the surface of an antiferroelectric bulk are presented

Diminution du taux d'ARNm du collagène VII chez des patients atteints d'une forme sévère d'épidermolyse bulleuse dystrophique

Les épidermolyses bulleuses dystrophiques récessives (EBDR) constituent un groupe de maladies héréditaires caractérisées par une fragilité cutanéo-muqueuse extrême associée à une anomalie des fibres d'ancrage essentiellement constituées de collagène VIL Dans les EBDR elles sont réduites voire complètement absentes. Récemment, une liaison génétique entre le phénotype des EBDR et le gène du collagène VII a été établie. Au cours de ce travail, on a étudié le taux des ARNm du collagène VII chez 7 patients atteints d'EBDR dont 6 sont atteints d'une forme sévère (EBDR mutilante de Rallopeau-Siemens). On a, ainsi, montré une forte diminution de ce taux chez 3 de ces derniers. Ces résultats suggèrent que, chez ces 3 patients, une mutation dans le gène du collagène VII peut être à l'origine d'une diminution du taux des ARN du collagène VII et, par conséquent, de la réduction ou l'absence des fibres d'ancrages responsable du phénotype de la maladie

Defect-induced perturbations of atomic monolayers on solid surfaces

We study long-range morphological changes in atomic monolayers on solid substrates induced by different types of defects; e.g., by monoatomic steps in the surface, or by the tip of an atomic force microscope (AFM), placed at some distance above the substrate. Representing the monolayer in terms of a suitably extended Frenkel-Kontorova-type model, we calculate the defect-induced density profiles for several possible geometries. In case of an AFM tip, we also determine the extra force exerted on the tip due to the tip-induced de-homogenization of the monolayer.Comment: 4 pages, 2 figure

Testing the skill of a species distribution model using a 21st century virtual ecosystem

Plankton communities play an important role in marine food webs, in biogeochemical cycling, and in Earth's climate; yet observations are sparse, and predictions of how they might respond to climate change vary. Correlative species distribution models (SDM's) have been applied to predicting biogeography based on relationships to observed environmental variables. To investigate sources of uncertainty, we use a correlative SDM to predict the plankton biogeography of a 21st century marine ecosystem model (Darwin). Darwin output is sampled to mimic historical ocean observations, and the SDM is trained using generalized additive models. We find that predictive skill varies across test cases, and between functional groups, with errors that are more attributable to spatiotemporal sampling bias than sample size. End-of-century predictions are poor, limited by changes in target-predictor relationships over time. Our findings illustrate the fundamental challenges faced by empirical models in using limited observational data to predict complex, dynamic systems

Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards.

The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost