Improving temporal resolution of ultrafast electron diffraction by eliminating arrival time jitter induced by radiofrequency bunch compression cavities

The temporal resolution of sub-relativistic ultrafast electron diffraction (UED) is generally limited by radio frequency (RF) phase and amplitude jitter of the RF lenses that are used to compress the electron pulses. We theoretically show how to circumvent this limitation by using a combination of several RF compression cavities. We show that if powered by the same RF source and with a proper choice of RF field strengths, RF phases and distances between the cavities, the combined arrival time jitter due to RF phase jitter of the cavities is cancelled at the compression point. We also show that the effect of RF amplitude jitter on the temporal resolution is negligible when passing through the cavity at a RF phase optimal for (de)compression. This will allow improvement of the temporal resolution in UED experiments to well below 100 fs

Kwalitatieve evaluatie van 10 jaar zorgcoördinatie en case management in de Oost-Vlaamse drughulpverlening: een rondvraag bij hulpverleners en cliënten

Sinds 10 jaar wordt door de Provincie Oost-Vlaanderen – in samenwerking met het provinciaal overlegplatform geestelijke gezondheidszorg (PopovGGZ) en alle betrokken voorzieningen – geïnvesteerd in zorgvernieuwing, coördinatie en afstemming van de zorg in de drughulpverlening. Dit heeft naast heel wat ‘onzichtbare’ realisaties (bv. grotere bekendheid van het zorgaanbod, de intakeprocedure en werkwijze van andere voorzieningen, betere samenwerking tussen voorzieningen als gevolg van meer (informele) contactmomenten), ook tot een aantal duidelijk tastbare resultaten geleid. Het betreft onder meer de oprichting van een netwerkcomité middelenmisbruik, de aanstelling van een zorgcoördinator, de uitbouw van een case managementteam en de organisatie van een driewekelijks cliëntenoverleg. Met name deze laatste twee realisaties komen in voorliggend onderzoeksrapport uitgebreid aan bod. We doen dit in de eerste plaats door de direct betrokkenen (cliënten, hulpverleners en verantwoordelijken) zelf aan het woord te laten. De bevindingen van onze kwalitatieve evaluatie worden afzonderlijk besproken met betrekking tot het cliëntenoverleg en case management. Vooreerst worden beide werkvormen beschreven en worden enkele cijfergegevens meegegeven over de interventie in kwestie. Daarna volgt een beknopte bespreking van de gevolgde methodologie. Bij de rapportage van de onderzoeksresultaten wordt een onderscheid gemaakt tussen de bevindingen van hulpverleners over het cliëntenoverleg, de visie van cliënten over case management en het perspectief van case managers en projectverantwoordelijken over deze laatste interventie. We sluiten af met een aantal globale conclusies en aanbevelingen voor de toekomstige praktijk, die we terugbrachten tot tien concrete suggesties ter optimalisatie van het cliëntenoverleg en het case management. In tegenstelling tot eerdere publicaties beroepen we ons in dit onderzoeksrapport slechts in beperkte mate op de literatuur. In voorliggend rapport wilden we vooral het ‘insider’-perspectief laten primeren en voor meer theoretische beschouwingen verwijzen we dan ook naar eerdere publicaties (cf. Vanderplasschen, 2004)

International value chains : opportunities and challenges for small and developing countries

While internationalisation can improve firm performance, it is often only the most productive firms that are able to internationalise (Wagner, 2005, 2012; Melitz, 2003). Recent reductions in transportation costs and trade barriers alongside technological advances have fragmented production into intermediate tasks that can be executed in several countries, creating international value chains (IVCs). These IVCs can act as a stepping stone for less productive firms to tap into international markets, and benefit from learning-by-doing, without taking on all the tasks in the value chain, thereby lowering the entry requirements for internationalisation associated with exports (OECD, 2008). This article examines the opportunities and challenges of IVCs for SMEs in small and developing countries and, in a final section, applies some of these lessons to Scotland

Lipase activity in vesicular systems: Characterization of candida cylindracea lipase and its activity in polymerizable dialkylammonium surfactant vesicles

Lipase from Candida cylindracea (CCL) was incorporated into polymerizable positively charged dialkylammonium bromide surfactant vesicles. The enzyme was incorporated by the use of the dehydration-rehydration method or by incubation. In the latter case, trapping efficiencies of up to 100% could be obtained. Activities of free and vesicle-incorporated CCL were tested for three triglycerides: triacetin, tributyrin, and tricaprylin. Enzyme activity was lowest in homogeneous mixtures (triacetin and small concentrations of tributyrin) and highest in heterogeneous mixtures (tricaprylin and high concentrations of tributyrin). Entrapment in vesicular systems is advantageous, especially in homogeneous reaction mixtures and in the case of the production of insoluble fatty acid (caproate), because inhibition by the acid can be suppressed. The influence of several surface-active additives, including vesicles, on the activity of lipase in triglyceride assays was tested. Vesicles have a positive influence on the activity, whereas other positively charged additives act as inhibitors. In the case of tricaprylin assays, the positively charged additives increase the activity. Finally, tryptic digestion for free and incorporated CCL were compared. Free CCL is readily inactivated, whereas incorporated enzyme is protected from proteolytic degradation

Imaging surface plasmon resonance for multiplex microassay sensing of mycotoxins

A prototype imaging surface plasmon resonance-based multiplex microimmunoassay for mycotoxins is described. A microarray of mycotoxin–protein conjugates was fabricated using a continuous flow microspotter device. A competitive inhibition immunoassay format was developed for the simultaneous detection of deoxynivalenol (DON) and zearalenone (ZEN), using a single sensor chip. Initial in-house validation showed limits of detection of 21 and 17 ng/mL for DON and 16 and 10 ng/mL for ZEN in extracts, which corresponds to 84 and 68 µg/kg for DON and 64 and 40 µg/kg for ZEN in maize and wheat samples, respectively. Finally, the results were critically compared with data obtained from liquid chromatography-mass spectrometry confirmatory analysis method and found to be in good agreement. The described multiplex immunoassay for the rapid screening of several mycotoxins meets European Union regulatory limits and represents a robust platform for mycotoxin analysis in food and feed sample

Cell proliferation, cell shape, and microtubule and cellulose microfibril organization of tobacco BY-2 cells are not altered by exposure to near weightlessness in space

The microtubule cytoskeleton and the cell wall both play key roles in plant cell growth and division, determining the plant’s final stature. At near weightlessness, tubulin polymerizes into microtubules in vitro, but these microtubules do not self-organize in the ordered patterns observed at 1g. Likewise, at near weightlessness cortical microtubules in protoplasts have difficulty organizing into parallel arrays, which are required for proper plant cell elongation. However, intact plants do grow in space and therefore should have a normally functioning microtubule cytoskeleton. Since the main difference between protoplasts and plant cells in a tissue is the presence of a cell wall, we studied single, but walled, tobacco BY-2 suspension-cultured cells during an 8-day space-flight experiment on board of the Soyuz capsule and the International Space Station during the 12S mission (March–April 2006). We show that the cortical microtubule density, ordering and orientation in isolated walled plant cells are unaffected by near weightlessness, as are the orientation of the cellulose microfibrils, cell proliferation, and cell shape. Likely, tissue organization is not essential for the organization of these structures in space. When combined with the fact that many recovering protoplasts have an aberrant cortical microtubule cytoskeleton, the results suggest a role for the cell wall, or its production machinery, in structuring the microtubule cytoskeleto

Failure temperature of a System Comprising a Restrained Column Submitted to Fire

The problem of columns submitted to fire is discussed in the intoduction with an emphasis on the differences between the case of a column acting as a single element or being part of a frame. In the latter case, failure of the column does not necessarily lead to the failure of the structure. The basic principles of the arc-length technique are given, first for the way it is applied traditionally at room temperature, then for the way it can be applied to extend a numerical simulation beyond the moment of local failures in case of fire. The technique is then applied to the case of restrained columns and it is shown how it is possible to obtain a safe estimate of the critical temperature of the column leading to the failure of the structure, even if the degree of restraint apllied to the column is unknown

Präoperative Diagnostik des Pankreaskarzinoms

Das präoperative Staging des Pankreaskarzinoms ist wenig normiert und oft bezüglich der Resektabilität mäßig informativ. Ziel dieser Studie ist, aus der Vielzahl der Stagingmethoden die für die Operationsplanung aussagekräftigsten herauszufinden. Es wurden hierzu 28 Patienten mit Pankreas- und Papillenkarzinom mittels MRT, 55 mittels CT, 45 mittels IDUS und 47 mittels EUS, sowie 18 Patienten mit allen vier Methoden untersucht. Die Ergebnisse der Untersuchungen wurden mit der postoperativen Histologie und dem Operationsbefund nach der TNM-Klassifikation verglichen. Die Accuracy der Beurteilung der Irresektabilität konnte durch die Kombination von CT und IDUS bzw. MRT und IDUS im Vergleich zu den Einzeluntersuchungen deutlich gesteigert werden. Eine Kombination aller Untersuchungsmethoden erbrachte unwesentlich bessere Ergebnisse bei nahezu identischen 95 %-Konfidenzintervallen und erheblichen Mehrkosten und Mehraufwand. Die Kombination einer schnittbildgebenden mit einer invasiven Methode erbringt somit eine Verbesserung der Aussagekraft des präoperativen Stagings und sollte zur Standarddiagnostik werden

Septic Arthritis Caused by Legionella dumoffii in a Patient with Systemic Lupus Erythematosus-Like Disease

We describe a patient with systemic lupus erythematosus (SLE)-like disease on immunosuppressive treatment who developed septic arthritis of the knee involving Legionella dumoffii. Cultures initially remained negative. A broad-range 16S PCR using synovial fluid revealed L. dumoffii rRNA genes, a finding that was subsequently confirmed by positive Legionella culture results