130,828 research outputs found
Aphids: Biology, Ecology, and Management
No full textPast studies have identified 18 species of aphids attacking tomato in open-field agriculture and greenhouses. However an in-depth review of the literature reveals only two species, Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer), as frequent and common aphid pests of tomato throughout the world. In this chapter, we review the identification, general biology, distribution, host range, and seasonal occurrence of these two aphids and discuss how they damage plants. We present research that has attempted to develop sampling strategies and devise economic thresholds. Furthermore, we review the history and current status of strategies used to manage M. euphorbiae and M. persicae. These strategies are presented under the broad headings of chemical control, biological control, host-plant resistance, cultural control, and others. With the wealth of information contained in this chapter, the reader will gain valuable insight into where we have been, and where we are likely to proceed in dealing with aphids on tomato
D. Perring & S. Roskamps, Early Development of Roman London West of the Walbrook
No full textVerhaeghe Frans. D. Perring & S. Roskamps, Early Development of Roman London West of the Walbrook. In: L'antiquité classique, Tome 62, 1993. pp. 598-599
3-Dimensional simulation of multistage depressed collectors on microcomputers.
No full textA three-dimensional (3-D) package for simulation of asymmetric and crossed-field multistage depressed collectors for microwave tubes has been developed. This package is based upon the 3-D finite-difference code KOBRA3-INP. The main features of the package are a user-friendly input interface, postprocessors for collector analysis and calculation of secondary electron trajectories, and versatile output graphics. Both PC and. mainframe versions of the package have been developed. The results of simple benchmark tests and those of simulation and analysis of asymmetric and crossed-field collectors including the effects of secondary electrons are presented. It is found that the asymmetric hyperbolic electric field collector shows very low backstreaming. It is shown that the representation of trajectories in energy space gives a better insight into the behavior of individual trajectories than plotting in coordinate-space. The package will be useful for designing novel types of depressed collector
The making of Britain’s first urban landscapes: the case of late Iron Age and Roman Essex
No full textThis paper presents preliminary research into the social and economic impact of early urban settlement in Britain, focusing on the case-study area of Late Iron Age to Roman Essex. Through fresh analysis of ceramic assemblages from Colchester and Heybridge, we describe hitherto unrecognised socio-cultural groupings and identities through subtle differences in the deposition of pottery in the generations before and after conquest. The concluding discussion concentrates on problems that we still have to address in describing the economic basis of early urban society in Britain
'Gnosticism' in fourth century Britain: the Frampton mosaics reconsidered
No full textRecent years have seen a renewed interest in the significance of the mosaic designs employed in Roman houses. Studies have concentrated on establishing the mythological sources of the images chosen, and on describing the social and architectural contexts within which such art was used. It has long been noted that some of the subjects preferred in fourth-century Britain suggest allegorical references to the hereafter, although it has also been observed that the ‘search for profound and coherent allegories may exaggerate the significance which the wealthy British patrons imparted to the floors of the great halls or dining-rooms of their villas’. Ling, in particular, has cautioned against reading exaggerated meanings into ambivalent images that may simply have been chosen to vaunt erudite taste
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Fashions of Yesteryear
No full textNewspaper Article - 'Fashions of Yesteryear'. Edmonton, AB. 1959Alberta Women's Institutes; AWI CollectionFASHIONS OF YESTERYEAR: Women brought
along an amazing variety of costumes for party
light at the Jubilee convention of Alberta's Women's
istitutes in Edmonton. Here all dressed up are:
Iss D. Perring, Edmonton ( wearing her great-''
it's wedding dress); Mrs. C. A. Quail, Round )
WI; Mrs. C. L. Alexander, Cayley; Mrs. W. R.
Ford, Coutts ( AWI president)
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