Search results for "crossing"
showing 10 items of 167 documents
Crossing a Multi-Lane Street: Irrelevant Cars Increase Unsafe Behavior
2011
Before crossing a road or an intersection, road users have to determine among the surrounding traffic whether or not they have enough time to safely complete their maneuver. Temporal judgments have been investigated for single cars approaching an intersection, however, close to nothing is known about how street-crossing decisions are being made when several vehicles are simultaneously approaching in two adjacent lanes. We conducted a simulator experiment in which observers indicated whether or not they had enough time to complete safe street crossing. Traffic gaps were presented either with a single or two oncoming cars on different lanes, in such a way that in all cases, only the shortest …
Journeys from quantum optics to quantum technology
2017
Sir Peter Knight is a pioneer in quantum optics which has now grown to an important branch of modern physics to study the foundations and applications of quantum physics. He is leading an effort to develop new technologies from quantum mechanics. In this collection of essays, we recall the time we were working with him as a postdoc or a PhD student and look at how the time with him has influenced our research.
Multipactor prediction with multi-carrier signals: Experimental results and discussions on the 20-gap-crossing rule
2014
This work analyzes the 20-gap crossing rule from a theoretical point of view. It has been found that, depending on some signal parameters, the 20-gap-crossing rule yields predictions laying between two limit cases: It may be either excessively conservative or closer to breakdown value with little (or nonexistent) margin. Such limit cases have been experimentally assessed with two test campaigns in C and Ku-bands. © 2014 European Association on Antennas and Propagation.
Grid synchronization of DC energy storage using Voltage Source Inverter with ZCD and PLL techniques
2015
To increase the penetration of renewable energy sources, a proper energy storage is required. In this context, there is a growing concern about the use of energy storage for overcoming the intermittency of renewable energy sources as well as in demand side management. In order to accomplish grid synchronization of energy storage, proper power conditioning devices are required. This paper analyses single phase grid synchronization of DC energy storage using MATLAB Simulink ® environment. The considered power conditioning device is a Voltage Source Inverter (VSI), which is controlled using two methods called (i) traditional Zero Crossing Detection (ZCD) technique and (ii) the phase detector b…
Effects of population outcrossing on rotifer fitness
2010
Abstract Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alterna…
Replication of linkage of familial hypobetalipoproteinemia to chromosome 3p in six kindreds
2002
Familial hypobetalipoproteinemia (FHBL) is a genetically heterogeneous condition characterized by very low apolipoprotein B (apoB) concentrations in plasma and/or low levels of LDL-cholesterol (LDL-C) with a propensity to developing fatty liver. In a minority of cases, truncation-specifying mutations of the apoB gene (APOB) are etiologic, but the genetic basis of most cases is unknown. We previously reported linkage of FHBL to a 10 cM region on 3p21.1-22 in one kindred. The objectives of the current study were to identify other FHBL families with linkage to 3p and to narrow the FHBL susceptibility region on 3p. Six additional FHBL kindreds unlinked to the APOB region on chromosome 2 were ge…
Recolonization after habitat restoration leads to decreased genetic variation in populations of a terrestrial orchid
2012
Colonization is crucial to habitat restoration projects that rely on the spontaneous regeneration of the original vegetation. However, as a previously declining plant species spreads again, the likelihood of founder effects increases through recurrent population founding and associated serial bottlenecks. We related Amplified Fragment Length Polymorphism markers genetic variation and fitness to colonization history for all extant populations of the outcrossing terrestrial orchid Dactylorhiza incarnata in an isolated coastal dune complex. Around 1970, D. incarnata suffered a severe bottleneck yet ultimately persisted and gradually spread throughout the spatially segregated dune slacks, aided…
Infectious transfer of a fertility factor inStreptomyces coelicolor
1973
SUMMARYInitial Fertility (IF) strains ofStreptomyces coelicolorare able to convert recipient strains (UF) to the IF condition by contact, without concomitant transfer of chromosomal markers. The conversion is prevented by the presence of acridine orange in the medium of the mixed culture. Acridine orange is also moderately effective in inducing the formation of UF variants from IF-treated strains. No effect of the drug is observed on UF variant formation from Normal Fertility (NF) strains nor on the behaviour of the fertility factor in NF × UF mixed cultures. The hypothesis is put forward that the fertility factor works as an episome inS. coelicolor, fixed to the chromosome in the NF strain…
RAPD variation within and among natural populations of outcrossing willow-leaved foxglove (Digitalis obscura L.)
1999
Random amplified polymorphic DNA (RAPD) markers were used to assess levels and patterns of genetic diversity in Digitalis obscura L. (Scrophulariaceae), an outcrossing cardenolide-producing medicinal plant species. A total of 50 plants from six natural populations on the Iberian Peninsula were analysed by six arbitrarily chosen decamer primers resulting in 96 highly reproducible RAPD bands. To avoid bias in parameter estimation, analyses of population genetic structure were restricted to bands (35 of 96) whose observed frequencies were less than 1–3/n in each population. The analysis of molecular variance (AMOVA) with distances among individuals corrected for the dominant nature of RAPDs (g…
Subrepeats result from regional DNA sequence conservation in tandem repeats in Chironomus telomeres
1990
Repeat units, widespread in eukaryotic genomes, are often partially or entirely built up of subrepeats. Homogenization between whole repeat units arranged in tandem usually can best be understood as a result of unequal crossing over. Such a mechanism is less plausible for maintaining similarities between subrepeats within a repeat unit when present in a regular array. In Chironomus telomeres, large blocks of tandemly repeated approximately 350 base-pair units contain two or three pairs of subrepeats with high mutual identities, embedded in linker DNA, non-repetitive within the repeat unit. Measurements of evolutionary base changes in two closely related species, Chironomus tentans and Chiro…