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Cassava-Mealybug interactions

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ISBN: 9782709922814 Year: DOI: 10.4000/books.irdeditions.9865 Language: English
Publisher: IRD Éditions
Subject: Science (General)
Added to DOAB on : 2017-07-04 12:05:58
License: OpenEdition Licence for Books

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Most basic information on plant-mealybug interactions during the last decade has come from research on the cassava Manihot esculenta Crantz (Euphorbiaceae) system with two mealybug species, namely Phenacoccus manihoti Matile-Ferrero and Phenacoccus herreni Cox and Williams (Sternorrhyncha: Pseudococcidae). Both these insects cause severe damage to cassava in Africa and South America, respectively. This book reviews these interactions (plant selection by the insects, nutritional requirements, influence of the climate, intrinsic and extrinsic plant-defence mechanisms). It should be useful for entomologists, crop scientists, agronomists and ecologists as well as for teachers and students.

Language Parasites: Of Phorontology

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ISBN: 9780998531861 Year: Pages: 136 DOI: 10.21983/P3.0169.1.00 Language: English
Publisher: punctum books
Subject: Science (General)
Added to DOAB on : 2019-06-12 09:24:33
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Who speaks when you speak? Who writes when you write? Is it “you”—is it the “I” that you think you are? Or are we the chance inheritors of an invasive, exterior parasite—a parasite that calls itself “Being” or “Language?” If our sense of self is best defined on the basis of an exterior, parasitical force that enters us from the outside, then the “self” is no longer a centralized or agential “inside,” but rather becomes reconfigured as the result of an “outside” that parasitizes the “inside”-as-host. Rough versions of this model can be found in several traditions of continental philosophy: in Lacan, Derrida, Serres, Kristeva, Foucault, Baudrillard, to name a few. However, the full implications of this ontological model have yet to be addressed: what are its consequences for a theory of subjects, objects, and the agencies that intersect with them? How does this framework alter our understandings of the human and the non-human, the vital and the material? An off-kilter point of view is required to consider this historical and philosophical situation. Language Parasites argues that the best way to conceive of the “self” or “subject” as something linguistically and ontologically constituted by an aggressive and parasitical outside is by asking the following question: “what is the being of a parasite?” In addressing this challenge, Braune combines speculative philosophy with ’Pataphysics (the absurdist science, invented by Alfred Jarry, that theorizes a physics beyond both the para and the meta, resulting in the pata). These theoretical collisions betray a variety of swerves that extend to the social (as a parasite semiotics), the cultural (as the invasive force of memes), the aesthetic (as the transition of postmodernism to postmortemism), the linguistic (as found in Saussure’s paranoid researches into the paragram), the poetic (as seen in Christopher Dewdney’s journey into “Parasite Maintenance” and Christian Bök’s attempts to embed a poem in a bacterium), and the literary (as para-cited in Henry Miller’s experience of housing a parasite named “Conrad Moricand”). The “voice” of the parasite can be found in what Saussure calls the “paragram”—the uncanny messages that lurk hidden underneath the written word. And what does the parasite say? Or, does its speech reject human ears?

Drug Development for Parasite-Induced Diarrheal Diseases

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889452484 Year: Pages: 177 DOI: 10.3389/978-2-88945-248-4 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Microbiology
Added to DOAB on : 2018-02-27 16:16:44
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One of the top four contributors to the global burden of disease is diarrheal infections. Intestinal parasites are major causes of morbidity and mortality associated with diarrheal diseases in both the developed and developing world. Amebiasis is responsible for 50 million cases of invasive disease and 70,000 deaths annually in the world. Giardiasis has an estimated worldwide prevalence of 280 million cases annually. In developed countries, Giardia lamblia infects about 2% of adults and 6-8% of children. The prevalence of G. lamblia infection is generally higher in developing countries, ranging from 3% to 90%. Furthermore, giardial infections contribute substantially to the 2.5 million annual deaths from diarrheal disease. In Asia, Africa, and Latin America, about 500,000 new giardiasis cases are reported each year. Cryptosporidium accounts for 20% and 9% of diarrheal episodes in children in developing and developed countries, respectively. Infection with Cryptosporidium can be chronic and especially debilitating in immunosuppressed individuals and malnourished children. A recent study to measure disease burden, based on disability-adjusted life years (DALYs), found that cryptosporidiosis and amebiasis produce about 10.6 million DALYs. This exceeds the DALYs of any helminth infection currently being targeted by the World Health Organization for preventive chemotherapy. Because of its link with poverty, Giardia and Cryptosporidium were included in the WHO Neglected Diseases Initiative in 2004. E. histolytica, G. lamblia, and C. parvum have been listed by the National Institutes of Health (NIH) as category B priority biodefense pathogens due to low infectious dose and potential for dissemination through compromised food and water supplies in the United States. Despite the prevalence of amebiasis, giardiasis, and cryptosporidiosis there are no vaccines or prophylactic drugs. The first-line drugs for invasive amebiasis and giardiasis chemotherapy are nitroimidazoles, with the prototype, metronidazole, being the most common drug used worldwide. Metronidazole has been shown to be both mutagenic in a microbiological system and carcinogenic to rodents, and frequently causes gastrointestinal side effects. In spite of the efficacy of nitroimidazole drugs, treatment failures in giardiasis occur in up to 20% of cases. Clinical resistance of G. lamblia to metronidazole is proven and cross resistance is a concern with all commonly used antigiardial drugs. Nitazoxanide, the only FDA-approved drug for the treatment of cryptosporidiosis, is effective in the treatment of immunocompetent patients and partially effective for immunosuppressed patients. Therefore, it is critical to search for more effective drugs to treat amebiasis, giardiasis, and cryptosporidiosis. This Research Topic for Frontiers in Microbiology will explore the recent progress in drug development for parasitic diarrheal diseases. This includes an understanding of drug resistance mechanisms. We would also welcome submissions on the drug development for other diarrheal parasites. We hope that this research topic will include a comprehensive survey of various attempts by the parasitology research community to create effective drugs for these diseases.

Parasites et parasitoses des poissons

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ISBN: 9782759222230 Year: DOI: 10.35690/978-2-7592-2223-0 Language: French
Publisher: éditions Quae
Subject: Agriculture (General)
Added to DOAB on : 2019-11-10 11:21:03
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This richly-illustrated work offers a representative panorama of parasitic agents encountered in fish. Based on the new phylogenetic classification concepts, it emphasises the biological properties, epidemiology and clinical effects of groups of organisms in question, in the light of cognitive advances made possible by the new biology tools. It is intended for a wide audience, from the world of aquaculture to animal health and teaching as well as to researchers.

Interaction of Trypanosoma cruzi with Host Cells

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193370 Year: Pages: 97 DOI: 10.3389/978-2-88919-337-0 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology --- Science (General) --- Microbiology
Added to DOAB on : 2013-09-03 13:00:53
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Trypanosoma cruzi is a pathogenic protozoan of the Trypanosomatidade Family, which is the etiological agent of Chagas’ disease. Chagas’ disease stands out for being endemic among countries in Latin America, affecting about 15 million people. Recently, Chagas has become remarkable in European countries as well due to cases of transmission via infected blood transfusion. An important factor that has exacerbated the epidemiological picture in Brazil, Colombia and Venezuela is infection after the oral intake of contaminated foods such as sugar cane, açai and bacaba juices. Trypanosoma cruzi is an intracellular protozoan that exhibits a complex life cycle, involving multiple developmental stages found in both vertebrate and invertebrate hosts. In vertebrate hosts, the trypomastigote form invades a large variety of nucleated cells using multiple mechanisms. The invasion process involves several steps: (a) attraction of the protozoan to interact with the host cell surface; (b) parasite-host cell recognition; (c) adhesion of the parasite to the host cell surface; (d) cell signalling events that culminate in the internalization of the parasite through endocytic processes; (e) biogenesis of a large vacuole where the parasite is initially located, and is also known as parasitophorous vacuole (PV); (f) participation of endocytic pathway components in the internalization process; (g) participation of cytoskeleton components in the internalization process; (h) transformation of the trypomastigote into the amastigote form within the PV; (i) lysis of the membrane of the PV; (j) multiplication of amastigotes within the host cell in direct contact with cell structures and organelles; (k) transformation of amastigotes into trypomastigotes, and (l) rupture of the host cell releasing trypomastigotes into the extracellular space. The kinetics of the interaction process and even the fate of the parasite within the cell vary according to the nature of the host cell and its state of immunological activation.

Roles and mechanisms of parasitism in aquatic microbial communities

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195886 Year: Pages: 153 DOI: 10.3389/978-2-88919-588-6 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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Next Generation Sequencing technologies are increasingly revealing that microbial taxa likely to be parasites or symbionts are probably much more prevalent and diverse than previously thought. Every well studied free-living species has parasites; parasites themselves can be parasitized. As a rule of thumb, there is an estimated 4 parasitic species for any given host, and the better a host is studied the more parasites are known to infect it. Therefore, parasites and other symbionts should represent a very large number of species and may far outnumber those with 'free-living' lifestyles. Paradoxically, free-living hosts, which form the bulk of our knowledge of biology, may be a minority! Microbial parasites typically are characterized by their small size, short generation time, and high rates of reproduction, with simple life cycle occurring generally within a single host. They are diverse and ubiquitous in the environment, comprising viruses, prokaryotes and eukaryotes. This Frontiers Research Topic sought to provide a broad overview but concise, comprehensive, well referenced and up-to-date state of the art for everyone involved with microbial parasites in aquatic microbial ecology.

Parasite Infections: From Experimental Models to Natural Systems

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889454853 Year: Pages: 294 DOI: 10.3389/978-2-88945-485-3 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Internal medicine
Added to DOAB on : 2019-01-23 14:53:42
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Eukaryotic parasites (including parasitic protozoans, worms and arthropods) are more complex and heterogeneous organisms than pathogenic bacteria and viruses. This notion implies different evolutionary strategies of host exploitation. Typically, parasites establish long-term infections and induce relatively little mortality, as they often limit pathological changes by modulating host cells and downregulating adverse immune responses. Their pattern of distribution tends to be endemic rather than epidemic. Despite these seemingly benign traits, parasites usually cause substantial chronic morbidity, thus constituting an enormous socioeconomic burden in humans, particularly in resource poor countries, and in livestock worldwide. Parasite-induced fitness costs are an evolutionary force that can shape populations and contribute to species diversity. Therefore, a thorough understanding of parasites and parasitic diseases requires detailed knowledge of the respective biochemical, molecular and immunological aspects as well as of population genetics, epidemiology and ecology. This Research Topic (RT) bridges disciplines to connect molecular, immunological and wildlife aspects of parasitic infections. The RT puts emphases on four groups of parasites: Plasmodium, Toxoplasma, Giardia and intestinal helminths. Co-infections are also covered by the RT as they represent the most common form of parasite infections in wildlife and domestic animal populations. Within the four types of parasites the following topics are addressed: (1) Experimental models: hypothesis testing, translation and limits. (2) Critical appraisal of experimental models. (3) Natural systems: Technological advances for investigations in natural parasite-host systems and studies in natural systems. (4) The urgent need for better models and methods in natural parasite systems. Hence, the RT covers and illustrate by the means of four main parasitic infections the parasite-host system at the molecular, cellular and organismic level.

Evolution, Composition and Regulation of Supernumerary B Chromosomes

Authors: --- --- ---
ISBN: 9783038977865 / 9783038977872 Year: Pages: 254 DOI: 10.3390/books978-3-03897-787-2 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology
Added to DOAB on : 2019-08-28 11:21:28
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Supernumerary B chromosomes (Bs) are dispensable genetic elements found in thousands of species of plants and animals, and some fungi. Since their discovery more than a century ago, they have been a source of puzzlement, as they only occur in some members of a population and are absent from others. When they do occur, they are often harmful, and in the absence of “selfishness”, based on mechanisms of mitotic and meiotic drive, there appears to be no obvious reason for their existence. Cytogeneticists have long wrestled with questions about the biological existence of these enigmatic elements, including their lack of any adaptive properties, apparent absence of functional genes, their origin, sequence organization, and co-evolution as nuclear parasites. Emerging new technologies are now enabling researchers to step up a gear, to look enthusiastically beyond the previous limits of the horizon, and to uncover the secrets of these “silent” chromosomes. This book provides a comprehensive guide to theoretical advancements in the field of B chromosome research in both animal and plant systems.

Keywords

repetitive elements --- RNA-Seq --- genomics --- evolution --- cytogenetics --- supernumerary elements --- extra chromosomes --- B chromosomes --- transmission --- drive --- host/parasite interaction --- supernumerary chromosomes --- karyotype evolution --- genome instability --- supernumerary chromosomes --- heterochromatin --- parent-of-origin effects --- paternal X chromosome --- maternal X chromosome --- controlling element --- teleost --- population analysis --- whole genome resequencing --- DNA copy number variation --- ribosomal DNA --- B chromosomes --- FISH (fluorescence in situ hybridisation) --- GISH (genomic in situ hybridisation) --- Prospero autumnale complex --- supernumerary chromosomal segments (SCS) evolution --- tandem repeats --- Drosophila --- supernumerary --- satellite DNA --- sSMC --- B chromosomes --- dot-like (micro) Bs --- karyotypic characteristics --- ?s --- B morphotypes --- Apodemus peninsulae --- maize B chromosome --- centromere --- inactivation --- reactivation --- de novo centromere formation --- epigenetics --- supernumerary chromosomes --- additional chromosomes --- chromosome polymorphism --- evolution --- B chromosomes --- karyotypes --- genome evolution --- interphase nucleus --- mammals --- genes --- repetitive DNA --- transcription of heterochromatin --- B chromosomes --- grasshoppers --- DNA composition --- repeat clusters --- euchromatin degradation --- microdissected DNA probes --- B chromosome --- satellite DNA --- mobile element --- organelle DNA --- chromosome evolution --- fluorescent in situ hybridization --- Orthoptera --- satellite DNA --- supernumerary chromosome --- RepeatExplorer --- supernumerary chromosomes --- B chromosomes --- next-generation sequencing --- coverage ratio analysis --- n/a --- B chromosome --- transmission --- origin --- drive --- n/a

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