Coalescence of the sites of cowpea mosaic virus RNA replication into a cytopathic structure

Cowpea mosaic virus (CPMV) replication induces an extensive proliferation of endoplasmic reticulum (ER) membranes, leading to the formation of small membranous vesicles where viral RNA replication takes place. Using fluorescent in situ hybridization, we found that early in the infection of cowpea protoplasts, CPMV plus-strand RNA accumulates at numerous distinct subcellular sites distributed randomly throughout the cytoplasm which rapidly coalesce into a large body located in the center of the cell, often near the nucleus. The combined use of immunostaining and a green fluorescent protein ER marker revealed that during the course of an infection, CPMV RNA colocalizes with the 110-kDa viral polymerase and other replication proteins and is always found in close association with proliferated ER membranes, indicating that these sites correspond to the membranous site of viral replication. Experiments with the cytoskeleton inhibitors oryzalin and latrunculin B point to a role of actin and not tubulin in establishing the large central structure. The induction of ER membrane proliferations in CPMV-infected protoplasts did not coincide with increased levels of BiP mRNA, indicating that the unfolded-protein response is not involved in this proces

Three Essays in Labor Economics

There are three chapters in this dissertation, each of which consists of a journal-length article. They are on the following subjects. The first chapter uses ordinances in San Francisco and Washington, D.C. to measure the effects of mandated paid sick leave on employment and wages. Using the Quarterly Census of Employment and Wages, an employment increase is observed in San Francisco and Washington, D.C. relative to places without an ordinance. This evidence suggests that sick leave mandates correct a market failure of under-provision of benefits. The second chapter uses a novel measure of distance based on the O*Net Content Model to show that information revealed by the spouses\u27 occupations predicts divorce. Spouses that are closer in terms of their occupations\u27 requisite knowledge are more likely to divorce, supporting the hypothesis that gains from specialization in a household renders a marriage more durable. Dissimilar spouses in terms of their occupations\u27 activities are more likely to divorce, suggesting that each spouse brings an inclination toward certain activities to the marriage that reflects compatible preferences for joint consumption of household public goods. The third chapter measures intertemporal earnings correlation across occupations in the U.S. using the Current Population Survey, 1971-2012. Then predictors of occupational earnings correlation are identified from among measures of occupational dissimilarity based on the O*Net database. Its findings consist of several surprisingly positive and U-shaped relationships between distance measures and measures of earnings correlation, as well as distance measures with negative estimated effects on earnings correlation

Dissimilar occupations and marital stability

We show that information revealed by the occupation choices of spouses predicts marital dissolution. Using a novel measure of occupational distance constructed from the O*Net Content Model, we find that spouses more closely matched in terms of their occupations' requisite knowledge are more likely to divorce. This supports the hypothesis that gains from division of labor within a household can render a marriage more durable. On the other hand, spouses that are dissimilar in terms of their occupations' activities are more likely to divorce. This suggests that each spouse brings an inclination toward certain activities to the marriage that reflects compatible preferences for joint consumption of household public goods

Neuromuscular control of Lokomat guided gait:evaluation of training parameters

De Lokomat is een looprobot die is ontwikkeld voor het revalideren van lopen. Deze robot combineert een exoskelet, dat de bewegingen van de benen robotisch kan ondersteunen, met een systeem voor gewichtsondersteuning en een loopband. Het effectief en efficiënt inzetten van Lokomat therapie vereist kennis over de neuromusculaire controle van Lokomat ondersteund lopen. Daarnaast is kennis nodig over de mate waarin de drie trainingsparameters (bewegingsondersteuning, gewichtsondersteuning en loopbandsnelheid) in staat zijn om de neuromusculaire controle van lopen te beïnvloeden. Dit wordt in huidig proefschrift onderzocht bij zowel gezonde deelnemers als patiënten die een beroerte hebben gehad. De resultaten laten zien dat Lokomat ondersteund lopen wordt gekenmerkt door vaste stappatronen en lage spieractiviteit van beenspieren, in zowel gezonde lopers als patiënten die een beroerte hebben gehad. Dit zou de effectiviteit van Lokomat therapie mogelijk kunnen verminderen, aangezien actieve bijdrage en variabele patronen belangrijke componenten van motorisch leren zijn. Daarnaast beïnvloedt het exoskelet van de Lokomat het looppatroon ook als het geen bewegingsondersteuning geeft. Hiermee moet rekening gehouden worden als de bewegingsondersteuning verlaagd wordt tijdens therapie. Met betrekking tot het variëren van de trainingsparameters, is met name het verhogen van de snelheid effectief in het verhogen van spieractiviteit. Een zo hoog mogelijke snelheid tijdens Lokomat therapie wordt dan ook geadviseerd. Over het algemeen bieden de resultaten van dit proefschrift waardevolle informatie over de implicatie van Lokomat therapie in de revalidatie. Verder onderzoek en ontwikkeling van robotica moet echter worden gestimuleerd om de toepassing van looprobots in de revalidatie te verbeteren