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Dynamic Phases (dynamic + phase)
Selected AbstractsStart-Up Transient in a Hall ThrusterCONTRIBUTIONS TO PLASMA PHYSICS, Issue 10 2006F. Taccogna Abstract For the first time a two dimensional axisymmetric fully kinetic Particle-in-Cell/Monte Carlo Collision (PICMCC) model is used to describe the start-up transient of the acceleration channel in a Hall thruster. The Poisson equation and a secondary electron emission model are invoked for the description of the plasma dynamic phase. Numerical results have been used to see the formation and evolution of the discharge inside the channel. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Towards a material ethnography of linguistic landscape: Multilingualism, mobility and space in a South African township1JOURNAL OF SOCIOLINGUISTICS, Issue 3 2009Christopher Stroud The study of multilingual landscapes promises to introduce a new perspective into theories and policies of multilingualism, and to provide essential data for a politics of language. However, the theorization of space and language underlying the notion of linguistic landscape is not able to capture the manifold complexities of (transnational) multilingual mobility that is characteristic of many late-modern multilingual societies. Basing our argument on signage data from a contemporary South Africa in a dynamic phase of social transformation, we argue that more refined notions of space coupled to a material ethnography of multilingualism could provide a theoretically more relevant and methodologically refocused notion of (multilingual) linguistic landscape. Specifically, we take an approach to landscapes as semiotic moments in the social circulation of discourses (in multiple languages), and view signs as re-semiotized, socially invested distributions of multilingual resources, the material, symbolic and interactional artifacts of a sociolinguistics of mobility. [source] Differentiation between completely hyalinized uterine leiomyomas and ordinary leiomyomas: Three-phase dynamic magnetic resonance imaging (MRI) vs. diffusion-weighted MRI with very small b-factorsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2004Ken Shimada MD Abstract Purpose To assess the possibility of differentiating between completely hyalinized leiomyomas and ordinary leiomyomas by using diffusion-weighted (DW) magnetic resonance imaging (MRI) (DWI) employing very small b-factors (b = 1.51 and 55.3 seconds/mm2) in comparison with three-phase dynamic MRI. Materials and Methods The subjects were 25 patients with 52 histopathologically confirmed uterine leiomyomas. All leiomyomas were divided into two histopathologic subtypes (5 completely hyalinized leiomyomas and 47 ordinary leiomyomas). For each leiomyoma, the enhancement index (EI) at three-phase dynamic MRI and apparent diffusion coefficient (ADC) were obtained and then compared. Results The EIs at second and third dynamic phases clearly differentiated the two types of leiomyomas without overlap of values. ADCs also clearly differentiated the two types of leiomyomas without overlap of values. Moreover, there were significant positive correlations between ADCs and EIs at all dynamic phases (r = 0.41,0.50, P < 0.01). Conclusion Not only three-phase dynamic MRI but also DWI with very small b-factors could be useful for differentiating completely hyalinized leiomyomas from ordinary leiomyomas. J. Magn. Reson. Imaging 2004;20:97,104. © 2004 Wiley-Liss, Inc. [source] Modulation of microtubule dynamics by the microtubule-associated protein 1aJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2009Elliott M. Faller Abstract Structural microtubule-associated proteins (MAPs) interact with microtubules to regulate the various dynamic stages of microtubules. The purpose of this study was to measure the impact of myc-tagged MAP1a fragments on microtubule dynamic phases in vivo. Cells from an epithelial kidney cell line (LLCPK1) that had been permanently transfected with human green fluorescent protein (GFP)-,-tubulin were transiently transfected with myc-tagged MAP1a fragments. Cells expressing MAP1a fragments were used to make direct observations of microtubule dynamics in living cells using fluorescence microscopy. All truncated MAP1a heavy chain fragments that contained the microtubule-binding domain were shown to associate with microtubules. Truncated fragments containing different regions of the projection domain of MAP1a demonstrated variations in their impact on microtubule dynamic events by promoting growth or inhibition of shortening phases. In contrast to MAP1a, MAP2c bundled microtubules and resulted in a complete arrest of microtubule motility. Results from the present study suggest that MAP1a promotes slow, stable growth of microtubules. This type of growth may be important in the maintenance and restructuring of adult neurons. © 2008 Wiley-Liss, Inc. [source] Changes in peak systolic velocity induced by chronic therapy with phosphodiesterase type-5 inhibitorANDROLOGIA, Issue 3 2006M. C. Sighinolfi Summary The aim of this study was to assess the influence of chronic therapy with phosphodiesterase type-5 inhibitor on penile haemodynamics at colour Doppler ultrasound. Thirty patients affected by erectile dysfunction (ED) of different aetiology tested with the International Index of Erectile Function (IIEF-5) were evaluated with penile colour Doppler ultrasound during basic and dynamic phases (10 ,g PGE1) before and after chronic self-administration of sildenafil citrate (dosage: 100 mg as required, two to three times a week) for a period of 5,20 months (mean: 12.3). Treatment was interrupted 14,21 days before the second ultrasound evaluation. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) were recorded by means of colour Doppler; cut off values were 25 and 5 cm s,1 respectively. Data were compared by nonparametric tests. Twenty-two of the 30 patients showed normal pre-treatment PSV, while eight of 30 had an insufficient arterial flow. Mean pre-treatment EDV was 4.7 ± 0.5. After chronic therapy with sildenafil, a global improvement of 10.5% on PSV was seen (P < 0.001), without any statistical difference between patients with normal pre-treatment peak and those with a borderline one. No statistically significant changes were found for EDV (P = 0.98). It is concluded that chronic therapy with phosphodiesterase-5 inhibitor results in a significant improvement in PSV values, probably due to a penile chronic vasoactive enhancement. [source] | ||||||||||