878 research outputs found

    Driven diffusive systems with mutually interactive Langmuir kinetics

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    We investigate the simple one-dimensional driven model, the totally asymmetric exclusion process, coupled to mutually interactive Langmuir kinetics. This model is motivated by recent studies on clustering of motor proteins on microtubules. In the proposed model, the attachment and detachment rates of a particle are modified depending upon the occupancy of neighbouring sites. We first obtain continuum mean-field equations and in certain limiting cases obtain analytic solutions. We show how mutual interactions increase (decrease) the effects of boundaries on the phase behavior of the model. We perform Monte Carlo simulations and demonstrate that our analytical approximations are in good agreement with the numerics over a wide range of model parameters. We present phase diagrams over a selective range of parameters.Comment: 9 pages, 8 Figure

    High quality ultrafast transmission electron microscopy using resonant microwave cavities

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    Ultrashort, low-emittance electron pulses can be created at a high repetition rate by using a TM110_{110} deflection cavity to sweep a continuous beam across an aperture. These pulses can be used for time-resolved electron microscopy with atomic spatial and temporal resolution at relatively large average currents. In order to demonstrate this, a cavity has been inserted in a transmission electron microscope, and picosecond pulses have been created. No significant increase of either emittance or energy spread has been measured for these pulses. At a peak current of 814±2814\pm2 pA, the root-mean-square transverse normalized emittance of the electron pulses is εn,x=(2.7±0.1)⋅10−12\varepsilon_{n,x}=(2.7\pm0.1)\cdot 10^{-12} m rad in the direction parallel to the streak of the cavity, and εn,y=(2.5±0.1)⋅10−12\varepsilon_{n,y}=(2.5\pm0.1)\cdot 10^{-12} m rad in the perpendicular direction for pulses with a pulse length of 1.1-1.3 ps. Under the same conditions, the emittance of the continuous beam is εn,x=εn,y=(2.5±0.1)⋅10−12\varepsilon_{n,x}=\varepsilon_{n,y}=(2.5\pm0.1)\cdot 10^{-12} m rad. Furthermore, for both the pulsed and the continuous beam a full width at half maximum energy spread of 0.95±0.050.95\pm0.05 eV has been measured

    Raccolta dati su alcuni nuovi materiali di impiego nel settore elettrico e elettronico

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    Questa tesi ha come scopo quello di fare una rassegna dei materiali di recente sviluppo nel settore elettrico ed elettronico, descrivendone le proprietà, lo sviluppo storico, le applicazioni attuali e anche quelle possibili in futuro che attualmente sono solo in fase di sperimentazione. Limitandosi all’illustrazione delle caratteristiche e dei campi di applicazione dei vari materiali, senza entrare nel dettaglio dei metodi costruttivi né sulle tecniche di ricerca attuali, questa tesi vuole descrivere la situazione dello stato attuale dei materiali elettromagnetici e dei loro differenti utilizzi

    (Re)connect social and environmental responsibility to learners’ living environments: Curriculum challenges and possible solutions for teaching-learning in Life Orientation

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    An analysis of the National Curriculum Statement indicates a strong focus on the promotion of knowledge in local context, whilst being sensitive to global imperatives. This implies that learning experiences must reflect local realities first; a call which compels teachers to adapt their teaching with the purpose to make learning relevant and meaningful for the learner. It is therefore an appropriate time to ask the key question: Do Life Orientation teachers (re)connect their teaching-learning on social and environmental responsibility with learners’ living environments to adhere to curriculum requirements of relevance and meaningfulness? The qualitative data obtained from 13 structured classroom observations, with specific reference to the topic social and environmental responsibility, revealed that Life Orientation teachers experienced challenges. Based on these qualitative findings the researchers propose place-based education as an appropriate teaching-learning strategy to (re)connect social and environmental responsibility with the learner’s living environment

    Distribution of cystic fibrosis patients not eligible to studied CFTR modulators in Europe

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    Studied Cystic Fibrosis (CF) modulators have been announced to cover 90% of all CF patients. A genotype-agnostic novel therapy for CF is under development, which will focus on people with CFwho have mutations that are not eligible for the approved small molecule modulators and triple combination therapies. The data in the European Cystic Fibrosis Society Patient Registry (ECFSPR) are used to provide a quantitative overview of eligible patients. Patients who are alive and seen during the 2017, or alive and not seenwere considered (excluding France who delivered the data directly to the sponsor). Not considered were patients F508del homozygotes eligible for elexacaftor/tezacaftor/ivacaftor, tezacaftor/ivacaftor, lumacaftor/ivacaftor, or heterozygotes eligible for elexacaftor/tezacaftor/ivacaftor. Neither were patients with at least one of the following mutations: E56 K, P67L, R74W, D110E, D110H, R117C, E193 K, L206W, R347H, R352Q, A455E, D579G, 711 +3A->G, E831X, S945L, S977F, F1052 V, K1060 T, A1067 T, R1070W, F1074L, D1152H, D1270N, 2789+5G->A, 3272-26A->G, 3849+10kbC->T (eligible for tezacaftor/ivacaftor, ivacaftor) and R117H, G178R, S549N, S549R, G551D, G551S, G1069R, R1070Q, G1244E, S1251N, S1255P, G1349D (eligible for ivacaftor). From the 41,264 patients registered in the ECFSPR for the 2017, 4,798 patients (12%) carry a genotype that is not eligible to the currentlyapproved modulators or the triple combo. The percentage of non-eligible patients varies from 2,3% in Ireland to 71,9% in Armenia. 2,954 of these patients are 11 years or older, 1,561 have a FEV1% of predicted value between 40% and 90%. In Europe approximately 88% of the patients will be eligible for the currently approved modulators or triple combo, in some countries this percentage is below 50%. With the ECFSPR data, a realistic and useful overviewcould be created to support the design of a study for patients that are not eligible to the currently available modulator and triple combination therapies

    The European Cystic Fibrosis Society Patient Registry (ECFSPR) data validation programme: accuracy and consistency of data

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    Background: The ECFSPR database for 2016 contains data of 44,719 patients from 31 countries. Data of high quality is essential for use in annual reports and epidemiological research. Methods: A validation programme was introduced to quantify consistency and accuracy of data-input at source level, with on-site visits to countries entering data directly in the ECFSTracker software. Data fields to verify: demographic, diagnostic and transplantation, anthropometric and best lung function measurement, bacterial infections, medications and complications. Accuracy was defined as the proportion of values entered in ECFSTracker matching the medical record, and definitions used by the ECFSPR (consistency) for randomly selected cases. Results: Ten out of 41 centres (24%) in 4 countries (Austria, Portugal, Slovakia, Switzerland), reporting 6550% of all patients in their countries, were selected. Demographic, diagnostic and transplant data were checked for 489 patients (21%*), clinical data for 463 patients (20%*) (2016 data). Data on birth, gender, and transplantation exceeded 98.8% accuracy. Anomalies on reported mutations was 0.9%; reliable source data based on genetic reports, were available in 3 out of 4 countries in 95,9%- 91,9% of all patients, 55,5% in one country. Antropometry (92,2%), lung function (86,4%), inhaled antibiotics (96.1%), DNase (89.1%), pancreatic enzyme use (97.6%) were accurate and consistent with the ECFSPR definitions, so were chronic Pseudomonas (95.0%), Burkholderia infection (97.0%), and hemoptysis (94.6%). Liver disease was reported inconsistently due to different interpretation of the definition and resulted in an accuracy of 86.8%. Conclusions: The ECFSPR dataset is highly accurate for most data verified at source level. To further optimize we recommend centres to use a reliable source for genetic information, adhere to the definition of best lung function, and the ECFSPR to redefine liver disease. *of the total patients in these countries

    Theory and particle tracking simulations of a resonant radiofrequency deflection cavity in TM110_{110} mode for ultrafast electron microscopy

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    We present a theoretical description of resonant radiofrequency (RF) deflecting cavities in TM110_{110} mode as dynamic optical elements for ultrafast electron microscopy. We first derive the optical transfer matrix of an ideal pillbox cavity and use a Courant-Snyder formalism to calculate the 6D phase space propagation of a Gaussian electron distribution through the cavity. We derive closed, analytic expressions for the increase in transverse emittance and energy spread of the electron distribution. We demonstrate that for the special case of a beam focused in the center of the cavity, the low emittance and low energy spread of a high quality beam can be maintained, which allows high-repetition rate, ultrafast electron microscopy with 100 fs temporal resolution combined with the atomic resolution of a high-end TEM. This is confirmed by charged particle tracking simulations using a realistic cavity geometry, including fringe fields at the cavity entrance and exit apertures
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