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Penetration and encapsulation of the larval endoparasitoid Exorista larvarum (Diptera: Tachinidae) in the factitious host Galleria mellonella (Lepidoptera: Pyralidae)
No full textThe tachinid fly Exorista larvarum (L.) (Diptera: Tachinidae) is a polyphagous
larval endoparasitoid that deposits its eggs on the host exoskeleton of lepidopteran
and tenthredinid larvae. The attachment of larval E. larvarum and the formation of the
respiratory funnel were studied during infestation in the last larval instar of the wax
moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae). The tachinid larvae burrow
through the host integument after hatching, using their robust cephalopharyngeal
skeleton, leaving a dark spot at the point of their penetration as a result of host
cuticle melanization. Endoparasitoid penetration induces the host cellular defence,
resulting in the formation of a haemocyte capsule consisting of multi-cellular sheaths.
This enveloping capsule later undergoes melanization, which is mostly obvious
towards the posterior part of the endoparasitoid. The endoparasitoid uses the
host encapsulation response to build a respiratory funnel from the modified host
integument, leading to the host surface. The encapsulated larva remains attached
to the respiratory funnel via an anal hook and cuticular spines until fully developed.
Additional immunohistochemical analyses were used to study host–parasitoid
interactions. Indirect immunofluorescence showed no labelling of potential tachinid
antigens and confirmed no effect on the surrounding host tissues. A simulated
parasitization with coated polybead microspheres revealed the mortal impact
of tachinid antigens to the host. Hosts injected with antigen-coated polybeads died as a consequence of an acute and extensive immunological response to
the tachinid antigens and not due to the trauma caused by foreign objects inside their
body.
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
Novel Discoveries in the Male Accessory Secretions of the Tsetse fly (A transcriptomic/proteomic analysis)
No full textTsetse flies are the sole vectors of the human and animal forms of African Trypanosomiasis, neglected diseases that affect the health and development of marginalized populations in sub-Saharan Africa. Vector population control is one of the primary methods to prevent trypanosomiasis transmission. However, little is known about the reproductive biology of tsetse flies. A particularly important aspect of tsetse reproductive biology, male seminal secretions, remains unstudied. Based upon the knowledge derived from other insects such as Drosophila and various mosquito species, the proteins contained within these secretions play an important roles in regulating sperm storage, sperm motility, sperm competition, female sexual receptivity, egg production, ovulation, reproductive tract morphology, feeding behavior and other aspects of fly biology. To establish a foothold on this aspect of tsetse reproductive biology, we undertook a project to sequence the transcriptome of the male accessory tissue in tsetse and to sequence the proteome of the male seminal secretions found within the female after mating.
Material for transcriptomic analysis was derived from dissected adult male reproductive tracts at different time points. Samples were collected from teneral, 3 day old (reproductively mature), and 6-8 hours post mating male flies. Male reproductive tracts were dissected into two fractions, testes and accessory glands. RNA isolated from these samples was used to construct 6 illumina libraries which were sequenced using paired end sequencing technology. To complement the transcriptomes, samples of male produced spermatophores were collected for proteomic analysis from the uterus of newly mated female flies. Protein samples were analyzed by LC-MS/MS. Male accessory and testes illumina sequencing data was analyzed to identify the most abundant transcripts within each library, compared between libraries to identify temporal and tissue specific differential expression patterns and compared with transcriptome data from adult female flies to identify male specific transcripts. The results of these analyses were then compared with the proteomic data to confirm transcriptomic predictions of secreted accessory proteins and identify additional unpredicted proteins.
Analysis of these data sets resulted in the identification of a novel set of male accessory genes/proteins. Our initial analysis has identified a total of 25 putative accessory gland proteins via cross referencing our tissue specific transcriptome and the spermatophore proteome. Of these proteins, only one of the predicted genes (a serine protease inhibitor from the BPTI/Kunitz family) is orthologus to an accessory protein identified within Drosophila. Many proteins identified are tsetse specific and novel. Three of these novel proteins are the most abundant proteins in the spermatophore. These three proteins form a novel tsetse specific gene family that appears to have arisen through tandem gene duplication events. Further functional analysis will be required to identify the role that these novel proteins play in tsetse reproductive physiology. However, while many of the proteins we have identified are not true orthologs to other characterized accessory proteins, their function appears to have remained orthologus to those of accessory proteins from other Dipteran species. These functions include serine protease inhibitors, odorant binding proteins, antioxidants, immune proteins, glycoproteins, endocuticle proteins and sperm binding proteins
Development of the larval parasitoid fly, Exorista larvarum (Diptera: Tachinidae) with emphasis in its movements and attachment strategy to the host tissue
No full textExorista larvarum (L.) is a polyphagous gregarious larval endoparasitoid of Lepidoptera. Female flies deposit macrotype eggs on the host surface. The newly-hatched larva penetrates the host integument, induces the formation of a primary integumental respiratory funnel and develops through three larval instars. Pupation generally occurs outside the host larval remains.
The morphology of larval E. larvarum was studied in its factitious host Galleria mellonella (L.) (Lepidoptera: Pyralidae). Last instar host larvae were exposed for parasitization to female flies and removed when the 3 - 5 eggs had been laid on their body. Parasitized larvae were dissected and fixed every day of the parasitoid development, which lasts 3 - 4 days from egg hatching to pupal stage at 26°C. Specimens were embedded in Histoplast II and sections 5 - 7 μm thick were stained with hematoxylin - eosin and Masson΄s trichrome stain. To obtain sections of better quality, the cryosection and rapid microscopic analysis were also used. Frozen sections were stained with azan or hematoxylin - eosin.
Here, we focus on the integument and related structures participating in the movements and attachment process of E. larvarum larva to the host tissue. The tachinid larva penetrates the host using the robust cephalopharyngeal skeleton that undergoes changes during larval development. Using mouthhooks, it feeds on host hemolymph and subsequently on fat body and other host tissues. During larval development the digestive tract gradually becomes more extensive and denotes a great increase in the third instar, which abandons the funnel and migrates in the host body cavity. The tracheal system with prominent respiratory plates is well developed in all larval instars. The larvae are equipped with a thick anal hook and numerous cuticular spines supporting the larva in their attachment to the respiratory funnel. The external morphology of E. larvarum larvae of all instars was studied by electron microscopy. The behaviour of E. larvarum larvae in the host tissues and the escape of the advanced-third instar larvae from the host carcass were documented in vivo using the light microscope
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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