1,722,617 research outputs found
Isolation and characterization of a novel lectin gene, Allium triquetrum agglutin, conferring insecticidal properties against Myzus persicae
No full textMyzus persicae, more commonly known as green peach aphid, is an important
pest in agriculture. Each year it causes great losses to agricultural and horticultural plants.
It feeds on sap in the phloem, the main transportation route for plant nutrients. It also
transmits more than 100 plant viruses, and as there are still no agrichemicals specifically
against viruses, farmers often spray large amounts of pesticides to protect their crops.
A group of widely-distributed plant proteins, termed lectins, have been recently
studied because of their insecticidal properties against aphids. Snowdrop lectin, Galanthus
nivalis agglutinin (GNA) was the first isolated monocot mannose-binding lectin,
conferring properties of resistance to sap-sucking or homopteran pests.
The aim of the project described in this thesis was to identify and express a novel
lectin in Arabidopsis thaliana and to assess the performance of the green peach aphid,
Myzus persicae, on both transgenic and wild type plants. A gene encoding a novel
mannose-binding lectin was cloned from Allium triquetrum (wild garlic). The full-length
cDNA of Allium triquetrum agglutinin (ATA) was 719 bp and contained a 522 bp open
reading frame encoding a 173 amino acid polypepetide. Homology analysis showed that
ATA has high similarity with other mannose-binding lectins and includes three putative
mannose-binding subdomains, which suggests that ATA may also confer resistance against
aphids. The pGreen 0029 vector and the 35S CaMV cassette were ligated to produce the
expression construct.
An expression vector was engineered using the pGreen vector together with
CaMV 35S promoter and the novel ATA gene was inserted. Transgenic Arabidopsis
thaliana plants were subsequently generated using the Agrobacterium-mediated floral dip
method. Six homozygous ATA-transformed lines and one empty vector-transformed
control line were obtained using kanamycin selection. Several key growth parameters of
the transgenic plants were assessed to demonstrate that expressing ATA causes few
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phenotypic changes to the host plant. The transgenic plants were subsequently used for
aphid bioassays, including choice and non-choice behaviour tests, Mean Relative Growth
Rate test, fecundity test, and survival test. The aphid bioassays revealed that (1) ATA does
not change the behaviour of aphids to choose a host; (2) Adults are more sensitive to ATA
than nymphs; (3) ATA has significant detrimental effects on aphid fecundity.
The results described in the thesis show that the production of Allium triquetrum
agglutinin in Arabidopsis confers partial resistance to the aphids, Myzus persicae. It is
likely that this lectin in related Brassicaceae plants could be used, perhaps in conjunction
with other pest-control measures in agriculture.
Key words: Allium triquetrum agglutinin, aphid bioassay, Arabidopsis thaliana, choice
test, fecundity test, lectin, non-choice test, mean relative growth rate, Myzus persicae,
pleiotropic effects, resistance against aphids, survival test
Migrant Students’ Social Integration Data
No full textOur study aimed to investigate how group permeability and parental involvement affect the relationship between perceived personal discrimination and social integration. A total of 755 migrant students at three schools in mainland China were included in the study. The results indicated that perceived personal discrimination negatively predicted group permeability, whereas group permeability had a positive effect on social integration. Group permeability partially mediated the relationship between perceived personal discrimination and social integration. In addition, parental involvement played a significant moderating role between perceived personal discrimination and group permeability and mitigated the negative effect of perceived personal discrimination on group permeability. These findings suggest that we could reduce migrant students’ perceived personal discrimination by improving their group permeability and parental involvement, thereby increasing their social integration
The impact of cross-cultural training for expatriates in a Chinese firm
No full textPurpose: the purpose of this paper is to explore the significance of cross‐cultural training and career attitudes for expatriation career move in the context of China, whether cross‐cultural training is perceived necessary, and the consequence of providing such cross‐cultural training.Design/methodology/approach: data were collected from 82 expatriates from a Chinese firm, some of whom were expatriated to a foreign country and others who were expatriated from foreign countries to China.Findings: expatriates adjusted well, and having a protean career attitude was a decisive factor. While the impact of cross‐cultural training prior to departure was not statistically significant, it was well received and considered important.Research limitations/implications: limitation is the limited sample size. Implications are presented for conducting cross‐cultural training.Practical implications: developing cross‐cultural training programs could add value to the firm and its people.Originality/value: using a particular Chinese firm the paper highlights the value and necessity of cross‐cultural training for successful expatriation
Phase-field modeling and simulation of desiccation-induced cracking
No full textWe developed a phase-field approach to model desiccation-induced fracture in porous media. The
model describes the coupling of deformation, fluid flow and fracture in partially saturated materials.
Different coupling options are discussed and compared, and physically motivated improvements
with respect to previous models are introduced. The discretization setting hinges upon a stabilized
low-order finite element to maximize efficiency within a three-dimensional implementation. We
also discuss the comparison of numerical results to predictions of semi-analytical approaches and to
experimental results
Isolable zwitterionic pyridinio-semiquinone ?-radicals: mild and efficient single-step access to stable radicals
No full textA rational design based on the proton-coupled electron transfer (PCET) concept allows us to structurally characterize for the first time isolable, air- and moisture-stable semiquinone radicals in a zwitterionic neutral form. The presence of an alkoxy and the bulky pyridinio substituents causes only a minor perturbation of either the redox potentials or the spectral UV-vis characteristics of the semiquinone core but significantly stabilizes the new radicals
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
sj-xlsx-1-pim-10.1177_14750902221110933 – Research Data for Numerical investigation of sloshing pressure distribution in a rectangular tank
No full textResearch Data, sj-xlsx-1-pim-10.1177_14750902221110933 for Numerical investigation of sloshing pressure distribution in a rectangular tank by Chenyi Wang, Changfang Zou, Jiayan Zhu, Jingchun Tang and Quanming Miao in Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment</p
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