1,721,051 research outputs found
The control of Nezara viridula L. with introduced egg parasitoids in Australia. A review of a ‘landmark’ example of classical biological control
No full textThe history of Nezara viridula egg parasitoid introductions into Australia is critically reviewed. Using largely unpublished file material information is presented on the source of parasitoids, specific identification of parasitoids, numbers of parasitoids reared and released, and establishment and effects in the field. At least four species of egg parasitoids, in three genera, have been introduced and liberated into Australia since biological control efforts were first begun in 1933. There are records of 11 introductions involving Trissolcus basalis (Wollaston) (Egypt 1933; West Indies 1952-53; South Africa 1980; Brazil 1980; U.S.A. 1979-8 l), Trissolcus mitsukurii (Ashmead) (Japan l962), Ooencyrtus submetallicus (Howard) (West Indies 1952-53), and Telenomus chloropus (Thomson) (Japan 1962; Japan via U.S.A. 1980). Doubt is cast on the specific status of introductions from Italy (1956) and Pakistan (1 961), which are recorded in the literature as T, basalis. Evidence is presented that there is currently not enough information available to determine the specific classifications of these importations. Three programs in which Australian field populations of Trissolcus were bred and released elsewhere in Australia are also recorded. Post-release evaluation of introduced N. viridula egg parasitoids in Australia is reviewed. It is proposed that there is only circumstantial evidence to support the claim that N. viridula is under ‘good’ biological control by T. basalis in Australia. Areas of investigation that are of the most significance to current workers in N. viridula biological control are highlighted in the discussion
Taeniogonalos raymenti Carmean and Kimsey (Hymenoptera: Trigonalidae) reared as a hyperparasite of Sturmia convergens (Weidemann) (Diptera: Tachinidae), a primary parasite of Danaus plexippus (L.) (Lepidoptera: Nymphalidae)
No full textTaeniogonalos raymenti is confirmed as a hyperparasitoid of the tachinid Sturmia convergens which parasitises larval Danaus plexippus. Trigonalids are indirect parasitoids and in this case we have direct evidence that wasp eggs must have been laid on the caterpillar's host plant, Asclepias fruticosa, before the secondary host, but not necessarily before the primary tachinid host, was present. Levels of hyperparasitism during our sampling period were very low at less than two percent
Five commercial citrus rate poorly as hosts of the polyphagous fruit flyBactrocera tryoni(Froggatt) (Diptera: Tephritidae) in laboratory studies
No full textQueensland fruit fly, Bactrocera tryoni (Froggatt), is a polyphagous pest, and many citrus types are included among its hosts. While quantification of citrus host use by B. tryoni is lacking, citrus is generally considered a ‘low pressure’ crop. This paper investigates B. tryoni female oviposition preference and offspring performance in five citrus types; Murcott mandarin (Citrus reticulata), Navel orange and Valencia orange (Citrus sinensis), Eureka lemon (Citrus limon) and yellow grapefruit (Citrus paradisi). Oviposition preference was investigated in laboratory-based choice and no-choice experiments, while immature survival and offspring performance were investigated by infesting fruits in the laboratory and evaluating pupal recovery, pupal emergence and F1 fecundity. Fruit size, Brix level and peel toughness were also measured for correlation with host use. Bactrocera tryoni demonstrated an oviposition preference hierarchy among the citrus fruits tested; Murcott and grapefruit were most preferred for oviposition and lemon the least, while preference for Navel and Valencia was intermediate. Peel toughness was negatively correlated with B. tryoni oviposition preference, while no significant correlations were detected between oviposition and Brix level or fruit size. Immature survival in the tested fruit was very low. Murcott was the best host (21% pupal recovery), while all other citrus types that showed pupal recovery of 6% or lower and no pupae were recovered from Valencia orange. In pupae recovered from Navel orange and lemon, adult eclosion was greatly reduced, while in grapefruit and lemon, no eggs were recovered from F1 adults. Based on these laboratory results, many commercial citrus varieties appear to be poor hosts for B. tryoni and may pose a low post-harvest and quarantine risk. These findings need to be confirmed in the field, as they impact on both pre-harvest and post-harvest countermeasures
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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Methylphenidate effects in attention deficit/hyperactivity disorder: electrodermal and ERP measures during a continuous performance task
No full textRationale: Previous research investigating the effects of stimulants, such as methylphenidate (MPH), on children with attention deficit/hyperactivity disorder (AD/HD) has rarely included autonomic measures of arousal.Objective: Our aim was to clarify the effects of MPH on central and autonomic measures in AD/HD children during a continuous performance task (CPT) using a naturalistic open-label study.Method: Thirty-six boys (18 AD/HD and 18 control) participated in a CPT over two trial periods, allowing a more valid estimate of the effects of medication, rather than assuming that retesting per se has no substantial impact. MPH was administered to the AD/HD group 1 h prior to the second trial. Errors and reaction time (RT) were recorded as measures of performance, electrodermal activity as an autonomic nervous system measure and event-related potentials (ERPs) as an index of central nervous system activity.Results: AD/HD children made more errors than controls in the first session, but no group differences were found after medication. No significant differences were observed for RT. Skin conductance level was found to be lower in AD/HD children than controls, but this difference was also ameliorated after medication. Conversely, mean skin conductance response to target stimuli was found not to differ between groups during the initial test phase but became significantly different in phase 2. ERP data showed topographic differences between groups in N1, P2, N2 and P3 at the initial test phase, which were reduced at the second test.Conclusion: Stimulant medication ameliorated some of the dysfunctions in AD/HD children, which are reflected in behavioural and ERP measures. These results, in combination with general differences in electrodermal activity, support a hypoarousal model of AD/HD, which can explain the action of MPH in these children
The effect of methylphenidate on response inhibition and the event-related potential of children with Attention Deficit/Hyperactivity Disorder
No full textChildren with Attention Deficit/Hyperactivity Disorder (AD/HD) appear to be deficient in inhibitory processes, as reflected in behavioural and electrophysiological measures. This study examined the effect of methylphenidate (MPH) on response inhibition in children with AD/HD. Event-related potentials (ERPs) and skin conductance level (SCL) were recorded from 18 boys with AD/HD and 18 controls while they performed a cued Go/Nogo task with 70% Go probability. All participants performed the task twice, with an hour interval between test sessions. At the beginning of this interval children with AD/HD took their normal morning dose of MPH. The AD/HD group showed lower SCL than controls pre-medication, a difference not found subsequent to the administration of MPH. While the AD/HD group made more overall errors (omission + commission) pre-medication, and continued to make more omission errors than controls post-medication, the groups became comparable on the number of commission errors, suggesting MPH ameliorates deficits in response inhibition. Children with AD/HD displayed enhanced N1 and P2 amplitudes, and reduced N2 amplitudes relative to controls. These differences were not significant post-medication, at least partly attributable to the action of MPH. This study is unusual in the concurrent examination of electrodermal and electrophysiological measures of medication effects in children with AD/HD, with the retesting of both the AD/HD and control groups allowing a more valid estimate of the effects of medication, rather than assuming that retesting does not have a substantial impact
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
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