305,725 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Structure elucidation of some insect pheromones : a contribution to the development of selective pest control agents
No full textThe use of pheromones is one of the methods currently being investigated intensively as an alternative method of insect control. The various ways in which pheromones might be used in insect control programmes are briefly discussed in Chapter 1.Chapter 2 gives a detailed description of the isolation and identification of the sex pheromone of the American cockroach, Periplaneta americana. The various techniques that have been used for the structure elucidation are described.The sex pheromone of P. americana contains two major components (periplanone-A and periplanone-B), as well as minute amounts of another four.Periplanone-B could be identified as (1 Z, 5 E)-1,10(14)-diepoxy- 4(15), 5-germacradiene-9-one. Periplanone-A proved to be very unstable, isomerizing to a biologically inactive compound. The instability of the compound rendered a complete structure elucidation impossible.The four minor compounds could not be collected in sufficient amounts to carry out a complete structure elucidation.Of the compounds reported to mimic the natural pheromone, only germacrene-D was found to do so. However, its threshold is very much higher than that of the natural pheromone. The same holds for the other reported mimics, even they do elicit electroantennogram responses. Regardless of concentration, none of the mimics elicit responses as marked as the natural pheromone.Apart from causing sexual excitation, periplanone-B also can attract males of P. americana.The isolation, identification and field evaluation of the sex pheromone of the leafroller moth, Archips podana, is described in Chapter 3. The pheromone consists of a mixture of equal amounts of cis -11-tetradecenyl acetate and trans -11-tetradecenyl acetate. Although the individual compounds are not attractive in field experiments, a 1:1 mixture of the two is capable of attracting many males of this species.Investigation of the sex pheromone of the false codling moth, Cryptophlebia leucotreta (Chapters 4 and 5) revealed that the pheromone is a mixture of equal amounts of cis -8-dodecenyl acetate and trans -8-dodecenyl acetate. This finding contradicts other reports which state that the pheromone of this insect is trans -7-dodecenyl acetate. Mixtures of cis -8- and trans -8-dodecenyl acetate in various ratios proved to be very attractive to males of this species.In Chapter 6 the isolation, identification and field evaluation of the sex pheromone of the potato tuberworm moth, Phthorimaea operculella, is described. The sex pheromone of this moth is a mixture of about equal amounts of trans -4, cis -7-tridecadienyl acetate and trans -4, cis -7, cis -10-tridecatrienyl acetate. These findings were confirmed by synthesis and by trapping experiments in the field
BIOCHEMICAL AND MOLECULAR MONITORING OF INSECTICIDE RESISTANCE IN CODLING MOTH POPULATIONS COLLECTED IN EMILA-ROMAGNA (ITALY) ORCHARDS.
No full textThe codling moth, Cydia pomonella is a major pest in most pome fruit orchards worldwide. Recently, under the selective pressure caused by an increasing number of chemical treatments the codling moth has progressively developed a reduced insecticide susceptibility primarily to organophosphates (acetylcholinesterase inhibitors), and to insect growth regulators (chitin synthesis inhibitors). Small-scale field trials along with bioassays and biochemical or molecular tests are often exploit to reveal the selection of resistance mechanisms in field, such as target site insensibility and enhanced detoxifying activities. In this vein direct AChE-1 gene sequencing and biochemical analysis (EST, GST and MFO activities) were performed in codling moth populations collected in several Emilia Romagna orchards having pest control difficulties. In all analysed populations, the reduced susceptibility to insecticide treatments seems mainly associated to an increased MFO activity while GST and EST detoxifying pathways are more rarely involved. Moreover electrophoretic profiles, show that EST isoforms may be detected in some OP resistant population. These differences may also occur in GST and MFO families, for which there are no currently available rapid qualitative test. It must be stressed that none of the examined populations possess target-site mutations within AChE-1 sequence. The prevalent metabolic profile emerging from our analyses results in agreement with that found in other European codling moth populations with a reduced susceptibility to pesticide treatments based on alternate use of organophosphates and IGR. Trials were carried out to evaluate the correlations between the laboratory results and the field responses of two codling moth populations
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Codling moth (Lepid.: Tortricidae): Disruption of sexual communication with an antipheromone [(E,E)-8,1O-dodecadien-1-O1 acetate]
Get PDFWhen broadcast applications of [E, E]-8,10-dodecadien-1l-ol acetate an antipheromone of the codling moth, <i>Cydia pomonella</i> (L.), were made to apple or pear orchards, the catch of male codling moths was reduced in traps baited with either synthetic sex pheromone or virgin females. When the antipheromone, at a rate of 11.25g AI/0.4 ha was applied broadcast to pear trees using a ground dispenser, male response to pheromone- or female-baited traps was completely inhibited for 9 days with no significant reduction thereafter. Based on these and earlier results, it is concluded that (E,E)-8,10-dodecadien-1l-o1 acetate inhibits male codling moth response, whether the sources are placed in close proximity to the attractive agent or distributed in a broadcast application. These results contradict previous arguments that antipheromones as a group may not be effective in the field when used to permeate large volumes of air
Use of Ethyl (E,Z)-2,4-decadienoate in Codling Moth Management: Stimulation of Oviposition
Get PDFThe effect of the pear volatile, ethyl (E,Z)-2,4-decadienoate (Et-E,Z-DD), on oviposition by codling moth, Cydia pomonella (L.), was evaluated in a series of choice and nochoice laboratory experiments and in subsequent field tests conducted in apple and walnut. Gray halobutyl elastomer septa loaded with 1.0 and 100.0 μg Et-E,Z-DD significantly increased the numbers of eggs laid by a laboratory population in 96 h no-choice assays by 2-fold. In addition, the number of eggs laid near the Et-E,Z-DD versus a solvent blank dispenser was significantly higher in choice bioassays across a similar range of septa loadings. Oviposition rates by a field-collected post-diapause strain of codling moth were significantly increased by the addition of a 1.0-μg septa versus a solvent blank dispenser in a no-choice bioassay. Field trials were conducted in apple and walnut to develop an artificial egg trap baited with Et-E,Z-DD to monitor codling moth oviposition. Septa loaded with 0.1 to 10.0 mg did not significantly increase oviposition versus solvent blank dispensers on a Mylar plastic collar trap or on the adjacent leaves and fruit in apple. Significantly more eggs were laid on the fruit and foliage than on the plastic collar. No eggs were deposited on non-bearing apple shoots baited with 0.1 – 40.0 mg Et-E,Z-DD septa. Similarly, no eggs were deposited on cylindrical wax paper-covered plastic traps baited with 10.0 μg to 1.0 mg Et-E,Z-DD septa in walnut orchards. The potential of Et-E,Z-DD to monitor codling moth’s oviposition in the field, stimulate oviposition by field-collected strains under laboratory conditions, and to improve pest control by disrupting host location are discussed
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
Get PDFThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Persistence of a commercial codling moth granulovirus product on apple fruit and foliage
Get PDFCodling moth, Cydia pomonella (L.), larval bioassays were carried out on apples and leaves collected from trees treated with the commercially available codling moth granulovirus, Virosoft CP4®, to estimate the persistence of the product over time. The virus had a significant effect on survival of laboratory derived codling moth larvae placed on apples collected up to five and eight days post-treatment. Larvae died with virus symptoms after feeding on treated foliage and the leaf bioassay was easier to count than the apple bioassay. A combination assay, exposing larvae to leaf discs and fruit may more accurately account for potential exposure of wild neonate codling moth to virus in treated orchards. The addition of fish, soybean or mineral oils to Virosoft CP4® treatments did not significantly increase the efficacy or persistence of the viral insecticide on apples in this study
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Female codling moth, Cydia pomonella (Lepidoptera: tortricidae), antennal responses to serial dilutions of apple volatile chemicals
Get PDFVolatile chemicals from apples collected during each of the two codling moth, Cydia pomonella, flights in central Washington were analyzed using gas chromatography coupled with electroantennal detection (GC-EAD) using serially diluted samples. More concentrated immature apple volatile chemical collections elicited significantly more antennal responses than less concentrated volatile chemical collections. Antennal responses of wild codling moths were compared to laboratory-reared moths at one concentration with no significant difference found. Four immature apple volatile chemicals elicited an antennal response at the lowest concentration and three of these were identified. These chemicals are: (Z)-3-hexenol, (d)-linalool, and (E,E)-[alpha]-farnesene. The fourth chemical eluted with the solvent peak during analysis preventing structural determination and indicating low boiling point and low molecular weight. These chemicals are of interest for understanding how codling moths use kairomones to find and select host for oviposition and, ultimately, developing attractants for female codling moths
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