Bibliographies thématiques / Protozoa

Sommaire

Articles de revues
Thèses
Livres
Chapitres de livres
Actes de conférences
Rapports d'organisations

Littérature scientifique sur le sujet « Protozoa »

Auteur : Grafiati

Publié le 4 juin 2021

Mis à jour le 1 août 2024

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Protozoa ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Protozoa"

Ohene-Adjei, Samuel, Ronald M. Teather, Michael Ivan et Robert J. Forster. « Postinoculation Protozoan Establishment and Association Patterns of Methanogenic Archaea in the Ovine Rumen ». Applied and Environmental Microbiology 73, n^o 14 (18 mai 2007) : 4609–18. http://dx.doi.org/10.1128/aem.02687-06.

Texte intégral

Résumé :

ABSTRACT Association patterns between archaea and rumen protozoa were evaluated by analyzing archaeal 16S rRNA gene clone libraries from ovine rumen inoculated with different protozoa. Five protozoan inoculation treatments, fauna free (negative control), holotrich and cellulolytic protozoa, Isotricha and Dasytricha spp., Entodinium spp., and total fauna (type A) were tested. We used denaturing gradient gel electrophoresis, quantitative PCR, and phylogenetic analysis to evaluate the impact of the protozoan inoculants on the respective archaeal communities. Protozoan 18S ribosomal DNA clone libraries were also evaluated to monitor the protozoal population that was established by the inoculation. Phylogenetic analysis suggested that archaeal clones associated with the fauna-free, the Entodinium, and the type A inoculations clustered primarily with uncultured phylotypes. Polyplastron multivesiculatum was the predominant protozoan strain established by the holotrich and cellulolytic protozoan treatment, and this resulted predominantly in archaeal clones affiliated with uncultured and cultured methanogenic phylotypes (Methanosphaera stadtmanae, Methanobrevibacter ruminantium, and Methanobacterium bryantii). Furthermore, the Isotricha and Dasytricha inoculation treatment resulted primarily in archaeal clones affiliated with Methanobrevibacter smithii. This report provides the first assessment of the influence of protozoa on archaea within the rumen microbial community and provides evidence to suggest that different archaeal phylotypes associate with specific groups of protozoa. The observed patterns may be linked to the evolution of commensal and symbiotic relationships between archaea and protozoa in the ovine rumen environment. This report further underscores the prevalence and potential importance of a rather large group of uncultivated archaea in the ovine rumen, probably unrelated to known methanogens and undocumented in the bovine rumen.

Styles APA, Harvard, Vancouver, ISO, etc.

Ffoulkes, D., et R. A. Leng. « Dynamics of protozoa in the rumen of cattle ». British Journal of Nutrition 59, n^o 3 (mai 1988) : 429–36. http://dx.doi.org/10.1079/bjn19880051.

Texte intégral

Résumé :

1. The dynamics of protozoa were studied in two groups of rumen-fistulated cattle fed on a basal diet of molassesad lib., with oaten chaff given at 6 or 18 g/kg live weight. This diet resulted in different mixtures of protozoal species in the populations in the rumen.2. The rumen protozoa were studied by intrarumen injections of protozoa labelled in vitro with [14CH3]choline. An indication of protozoal death and fermentation of protozoal cell residues was obtained by measuring14C loss via the methane pool.3. After a single injection of labelled protozoa, the decline in the specific radioactivity (μCi/g nitrogen) of the protozoal pool in the rumen indicated that first-order kinetic processes applied. Conversely the specific radioactivity of protozoa, incubated in rumen fluid, remained constant indicating no growth in vitro, presumably owing to a rapid exhaustion of essential nutrients.4. The protozoal populations in the rumen of cattle fed on the diet with the low level of oaten chaff were mainly small ciliates; but on the higher level of chaff in the diet, the large ciliates were a higher proportion of the total protozoal population present.5. The mean pool size of protozoa in the rumen was significantly larger and the protozoal half-life tended to be longer for cattle fed on the higher level of chaff in the diet. The apparent production rate of protozoa in cattle fed on each diet was not significantly different and there were no differences in the production rate of methane. The percentage losses of label from protozoa in the rumen via the methane pool were not significantly different on the two diets and indicated that 74% of the protozoa that were apparently irreversibly lost from the rumen could be accounted for by death and lysis in the rumen and therefore only 26% of protozoa apparently entered the lower digestive tract.

Styles APA, Harvard, Vancouver, ISO, etc.

Murphy, Brian G., Daniel Bradway, Timothy Walsh, George E. Sanders et Kevin Snekvik. « Gastric Cryptosporidiosis in Freshwater Angelfish (Pterophyllum Scalare) ». Journal of Veterinary Diagnostic Investigation 21, n^o 5 (septembre 2009) : 722–27. http://dx.doi.org/10.1177/104063870902100523.

Texte intégral

Résumé :

A freshwater angelfish ( Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

Styles APA, Harvard, Vancouver, ISO, etc.

Bird, Simon H., R. S. Hegarty et R. Woodgate. « Modes of transmission of rumen protozoa between mature sheep ». Animal Production Science 50, n^o 6 (2010) : 414. http://dx.doi.org/10.1071/an09216.

Texte intégral

Résumé :

Three experiments were conducted to evaluate routes by which viable rumen ciliate-protozoa may be transferred between mature sheep. Feed, water and faecal material were tested as possible vectors for protozoal transfer in addition to direct animal to animal contact. In Experiment 1, protozoa-free sheep were either offered or orally dosed with protozoa-contaminated material or allowed contact with faunated animals. The treated sheep were then monitored over a 4-week period for the appearance of protozoa in the rumen. Protozoa were successfully transferred to protozoa-free animals via contaminated water but no transfer occurred via feed or faeces or by direct animal to animal contact. In Experiment 2, the drinking water of penned faunated sheep was found to become contaminated with protozoa within 4–6 h of being placed in the pen. In Experiment 3, nine protozoa-free sheep were grazed in a paddock with a flock of 75 faunated ewes for periods of 1–3 weeks, and protozoa became established in one protozoa-free sheep. The results of these studies suggest that the most likely mode of transfer of protozoal cells from one sheep to another is via water, rather than by rumen fluid contaminating feed, or from faeces of faunated sheep. Further tests are required to demonstrate protozoal transmission via water occur under a range of conditions and inoculum levels.

Styles APA, Harvard, Vancouver, ISO, etc.

Bardi, Edoardo, Emilio Noviello et Lada Hofmannová. « Protozoa and protozoal infections in chelonians ». Journal of Exotic Pet Medicine 31 (octobre 2019) : 5–12. http://dx.doi.org/10.1053/j.jepm.2019.06.006.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rychert, Krzysztof, et Thomas Neu. « Protozoan impact on bacterial biofilm formation ». Biological Letters 47, n^o 1 (1 janvier 2010) : 3–10. http://dx.doi.org/10.2478/v10120-009-0017-x.

Texte intégral

Résumé :

Protozoan impact on bacterial biofilm formationConfocal laser scanning microscopy in combination with digital image analysis was used to assess the impact of protozoa on bacterial colonisation of surfaces. Bacterial biofilms were developed from activated sludge in microscope flow cells and were exposed to the grazing pressure of protozoa. The protozoan community from healthy activated sludge and a culture of flagellateBodo saltanswere used as grazers. Experiments comprised 48-h incubations in 3 treatment variants: bacteria with protozoa, bacteria with protozoa added after some time and bacteria without protozoa. When necessary, the elimination of protozoa from the inoculum was carried out with cycloheximide and NiSO4. Experiments demonstrated that protozoa from healthy activated sludge initially disturbed the biofilm development but later they could stimulate its growth. Similar results could be established in the experiment withBodo saltans(inoculum: 1000 cells/ml), however differences were not statistically significant. The finding that protozoa support biofilm development during specific stages may be relevant for biofilm studies with mixed environmental biofilm communities.

Styles APA, Harvard, Vancouver, ISO, etc.

Huws, S. A., M. R. F. Lee, A. H. Kingston-Smith, E. J. Kim, M. B. Scott, J. K. S. Tweed et N. D. Scollan. « Ruminal protozoal contribution to the duodenal flow of fatty acids following feeding of steers on forages differing in chloroplast content ». British Journal of Nutrition 108, n^o 12 (1 mars 2012) : 2207–14. http://dx.doi.org/10.1017/s0007114512000335.

Texte intégral

Résumé :

Ruminant products are criticised for their SFA content relative to PUFA, although n-6:n-3 PUFA is desirable for human health ( < 4). Rumen protozoa are rich in unsaturated fatty acids due to engulfment of PUFA-rich chloroplasts. Increasing the chloroplast content of rumen protozoa offers a potentially novel approach to enhance PUFA flow to the duodenum and subsequent incorporation into meat and milk. We evaluated protozoal contribution to duodenal n-3 PUFA flow due to intracellular chloroplast content. A total of six Holstein × Friesian steers were fed, in a two-period changeover design, either straw:concentrate (S:C, 60:40; DM basis; S:C, low chloroplast) or fresh perennial ryegrass (PRG; high chloroplast). Following 12 d adaptation to diet, ruminal protozoal and whole duodenal samples were obtained. N and fatty acid content of whole duodenum and rumen protozoal samples were assessed and protozoal 18S rDNA quantitative PCR performed, enabling calculation of protozoal N flow. The ratio of individual fatty acids:N in rumen protozoal samples was calculated to obtain protozoal fatty acid flows. Based on total fatty acid flow, contribution (%) of protozoa to individual fatty acid flows was calculated. Protozoal fatty acid data and microscopical observations revealed that protozoa were enriched with 18 : 3n-3 following PRG feeding, compared with the S:C diet, due to increased intracellular chloroplast content. However, duodenal protozoal 18S rDNA concentration post PRG feeding was low, indicating rumen retention of the protozoa. Nutrition influences the 18 : 3n-3 content of protozoa; the challenge is to increase protozoal flow to the small intestine, while maintaining sustainable rumen densities.

Styles APA, Harvard, Vancouver, ISO, etc.

Ndiaye, Mouhamadou, Khadim Diongue, Mame Cheikh Seck, Mamadou Alpha Diallo, Ekoué Kouevidjin, Aida Sadikh Badiane et Daouda Ndiaye. « Retrospective Assessment of The Intestinal Protozoan Distribution in Patients Admitted to The Hospital Aristide Le Dantec in Dakar, Senegal, from 2011 to 2020 ». Parasitologia 3, n^o 1 (23 décembre 2022) : 1–12. http://dx.doi.org/10.3390/parasitologia3010001.

Texte intégral

Résumé :

Infectious parasites, especially the intestinal protozoan parasites, continue to be a major public health problem in Africa, where many of the same factors contribute to the transmission of these parasites. This study was conducted to investigate the parasites causing intestinal protozoal infections diagnosed in Aristide Le Dantec hospital (Senegal). Direct examination and the Ritchie technique were used. Among the 3407 stool samples studied, 645 demonstrated the presence of intestinal protozoa in single parasitism, biparasitism, or polyparasitism, representing a prevalence of 18.93%. Out of a total of 645 protozoa, 579 (16.99%) were identified in monoparasitism in the following order: Entamoeba coli (6.87%) and Blastocystis hominis (5.69%) for low pathogenic species, and Entamoeba histolytica/dispar (2.31%) and Giardia intestinalis (1.32%) for pathogenic species. The rates of biparasitism and polyparasitism were 1.88% and 0.06%, respectively. The highest rate of parasites was 24.83% between the ages of 0–15 years. A logistical regression model indicated that intestinal protozoan infections were not associated with age groups. There was an association between age groups and Giardia intestinalis and Blastocystis hominis (p < 0.05). These results demonstrated the frequency of intestinal protozoa in Senegal. There is a need to implement treatment, prevention, and control measures to limit the circulation of these protozoan infections.

Styles APA, Harvard, Vancouver, ISO, etc.

Brinch, Ulla C., Flemming Ekelund et Carsten S. Jacobsen. « Method for Spiking Soil Samples with Organic Compounds ». Applied and Environmental Microbiology 68, n^o 4 (avril 2002) : 1808–16. http://dx.doi.org/10.1128/aem.68.4.1808-1816.2002.

Texte intégral

Résumé :

ABSTRACT We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either the whole soil sample or 25% of the soil volume, which was subsequently mixed with 75% untreated soil. For dichloromethane, we included a third protocol, which involved application to 80% of the soil volume with or without phenanthrene and introduction of Pseudomonas fluorescens VKI171 SJ132 genetically tagged with luxAB::Tn5. For both solvents, application to the whole sample resulted in severe side effects on both indigenous protozoa and bacteria. Application of dichloromethane to the whole soil volume immediately reduced the number of protozoa to below the detection limit. In one of the soils, the protozoan population was able to recover to the initial level within 2 weeks, in terms of numbers of protozoa; protozoan diversity, however, remained low. In soil spiked with dichloromethane with or without phenanthrene, the introduced P. fluorescens VKI171 SJ132 was able to grow to a density 1,000-fold higher than in control soil, probably due mainly to release of predation from indigenous protozoa. In order to minimize solvent effects on indigenous soil microorganisms when spiking native soil samples with compounds having a low water solubility, we propose a common protocol in which the contaminant dissolved in acetone is added to 25% of the soil sample, followed by evaporation of the solvent and mixing with the remaining 75% of the soil sample.

Styles APA, Harvard, Vancouver, ISO, etc.

Hastutiek, Poedji, Wiwik Misaco Yuniarti, Mufasirin Djaeri, Nunuk Dyah Retno Lastuti, Endang Suprihati et Lucia Tri Suwanti. « Prevalence and diversity of gastrointestinal protozoa in Madura cattle at Bangkalan Regency, East Java, Indonesia ». Veterinary World 12, n^o 2 (février 2019) : 198–204. http://dx.doi.org/10.14202/vetworld.2019.198-204.

Texte intégral

Résumé :

Aim: This study aimed to describe the gastrointestinal protozoa in Madura cattle at Bangkalan Regency, East Java, Indonesia. Materials and Methods: A total of 500 samples of Madura cattle feces were collected from 10 districts at Bangkalan Regency. Those ten districts represent the lowland and upland areas, and each district was represented by one village. The collected feces were examined using native, sedimentation, and floating methods. The species identification was determined by their morphology. Results: There were 357 (71.4%) samples positively infected with protozoan. The highest rate of sample with protozoan infection was at Kamal District (88.23%), and Bangkalan District (52.83%) was the lowest one. There were six species of protozoa that infected gastrointestinal tract; those are Eimeria spp., Balantidium spp., Isospora spp., Blastocystis spp., Entamoeba spp., and Cryptosporidium spp. The highest number of protozoa found in this research was Eimeria (53.42%) followed by Blastocystis (14.43%). In this study, we found that 295 samples (58.76%) infected by one kind of protozoa, 53 samples (10.56%) infected by two kinds of protozoa, and 11 samples (2.19%) infected by three kinds of protozoa. In addition, there were 65.54% of bulls infected with protozoa, considerably lower than cows (72.97%). Cattle aged 6 months-2 years old (73.39%) and >2 years old (71.25%) are known more prone to protozoan infections than cattle aged <6 months (66.15%). Conclusion: The present study revealed that protozoan infection of cattle is common in Bangkalan Regency. Studies focused on determining that the prevalence of protozoan, risk factors for the parasitism, and the geographic distribution are needed and will be effective guide for prevention and control measures.

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "Protozoa"

Menon, Kathleen I. « Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation ». Thesis, Menon, Kathleen I. (2002) Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation. PhD thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/201/.

Texte intégral

Résumé :

The purpose of the present study was to evaluate the potential usefulness of tubulin inhibitors when complexed with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) against a range of protozoan parasites. This approach involved investigations into the complexation of these drugs with HP-beta-CD, and subsequent investigations of these drugs and their complexes in regard to cytotoxicity, pharmacokinetics, in vitro efficacy against Giardia, Cryptosporidium and rodent malaria (Plasmodium chabaudi), and their in vivo efficacy against Giardia and malaria. Albendazole (ABZ) is a benzimidazole carbamate with a broad anti-parasite spectrum, while the dinitroanilines trifluralin (TF) and oryzalin (OZ) have recently been found to exhibit activity against certain parasites. All three compounds are microtubule antagonists in either nematodes or weeds and have poor aqueous solubility, with the solubility of ABZ and OZ dependent on pH. Cyclodextrins (CD) have a hydrophobic cavity that allows them to form inclusion complexes with hydrophobic drugs, resulting in increased drug aqueous solubility, and often, improved drug dissolution and bioavailability. Thus the complexation of these drugs with HP-beta-CD was investigated. All three compounds exhibited type AL phase solubility diagrams with HP-beta-CD complexation, with additional increases in ABZ and OZ solubility achieved through the manipulation of temperature and pH. OZ displayed a stronger interaction with HP-beta-CD when ionised over its neutral form. However, insufficient concentrations of the TF/HP-beta-CD complex were achieved for drug efficacy studies. The cytotoxicity of the drugs and their complexes was assessed using the assay kit Cytotox 96 with human carcinoma cells. This is a colourimetric assay that measures lactate dehydrogenase release as a consequence of compromised cellular and membrane integrity. Both ABZ and OZ are cytotoxic to rapidly proliferating and differentiating cells but are not cytotoxic to cells in the stationary phase. Complexation did not affect drug cytotoxicity. In pharmacokinetic studies, complexation improved ABZ (and metabolites) bioavailability, but had no significant affect on OZ bioavailability. In vitro drug assessment studies found ABZ to be highly effective against Giardia, and effectiveagainst Cryptosporidium and malaria. OZ on the other hand exhibited no activity against Giardia, but was effective against Cryptosporidium and malaria. Complexation did not improve the antiprotozoal efficacy of either ABZ or OZ. In particular, excess HP-beta-CD decreased the antigiardial effects of ABZ, possibly due to competitive complex formation. In addition, complexation did not improve the antiprotozoal effects of ABZ in vivo. However, the cytotoxic effect of the ABZ/HP-beta-CD complex was more evident in the treatment of malaria in vivo, resulting in increased anaemia and suppression in weight gain, due to the improved bioavailability of ABZ and metabolites. HP-beta-CD alone was found to be cytotoxic at greater than 2.5%, and inhibited Giardia both in vitro and in vivo at greater than 1% and 2% respectively. This was attributed to membrane disruption caused by the dissolution and removal of membrane components. In comparison, malaria grew better in the presence of HP-beta-CD in vitro, with no detrimental effect observed at up to 8% HP-beta-CD. This was attributed to either the increased solubilization of a necessary media component, or the complexation and removal of an inhibitory compound from the cultivation medium. Therefore HP-beta-CD complexation did not improve the antiprotozoal activity of the tubulin antagonists ABZ and OZ. However, the results of the pharmacokinetic studies suggest that anthelmintic activity of ABZ, particularly against systemic infections, may be improved with oral administration of the ABZ/HP-beta-CD complex. In addition, the antiparasitic activity of HP-beta-CD alone may be promising, especially against intestinal infections. Finally, the improved in vitro cultivation of P. chabaudi in the presence of HP-beta-CD presents a promising approach to its potential long term cultivation.

Styles APA, Harvard, Vancouver, ISO, etc.

Menon, Kathleen I. « Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation ». Access via Murdoch University Digital Theses Project, 2002. http://wwwlib.murdoch.edu.au/adt/admin/view/adt-MU20040820.133836.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Schwarz, Mathieu Vincent Julian. « Ciliaten (Protozoa, Ciliophora) des Reisfeldbodens ». [S.l. : s.n.], 2003. http://archiv.ub.uni-marburg.de/diss/z2003/0626/.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Wagener, Stefan. « Untersuchungen zur Ökophysiologie anaerober Protozoen / ». Konstanz : Hartung-Gorre, 1989. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=003306450&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Texte intégral

Résumé :

Thesis (doctoral)--Universität Konstanz, 1989.
Appended are reprints of two articles, in English, "Electromigration, a tool for studies on anaerobic ciliates," by Stefan Wagener, Claudius K. Stumm, and Godfried D. Vogels, and "Monoxenic culture of the anaerobic ciliate Trimyema compressum Lackey," by S. Wagener and N. Pfennig. Includes bibliographical references.

Styles APA, Harvard, Vancouver, ISO, etc.

Mardare, Cornelia. « Interactions of Mycobacterium bovis with protozoa and the occurrence of Mycobacterium bovis in environmental protozoa ». Thesis, University of Surrey, 2010. http://epubs.surrey.ac.uk/844633/.

Texte intégral

Résumé :

Bovine tuberculosis is in the UK a persistent disease, affecting cattle and badgers. The latter is suspected to be a reservoir for Mycobacterium bovis but the transmission between badgers and cattle remains unclear. Mycobacteria have been shown to survive ingestion by protozoa and some even multiplied inside amoebas. The aim of this study was to investigate some interactions of Acanthamoeba castellanii and Tetrahymena pyriformis with M bovis. Firstly, the long term survival of the bacilli in protozoa was monitored. Secondly, it was investigated whether bacilli internalized in protozoa cysts are protected from hypochlorous acid and desiccation. Thirdly, the identification of M bovis in environmental protozoa isolated from badger latrines was attempted. The long term incubation of M. bovis with A. castellanii showed that the amoebas had a negative effect on the survival of virulent M. bovis. M. bovis was not detectable after 6 months of coincubation but remained viable at high concentrations in the control experiments. This effect however, could not be seen in T. pyriformis. Cysts of A. castellanii did not protect M bovis from hypochlorous acid and desiccation. Results indicate that M. bovis was more susceptible to hypochlorous acid after the encystment in comparison with the controls. These findings suggest that A. castellanii contributes to the decrease of M. bovis and therefore, it can be suggested that protozoa might have a negative impact on the survival M. bovis in the environment. In one of the samples taken from Woodchester Park, acid fast rods could be identified. Acid fast microorganisms were also identified in trophozoites of protozoa. This indicates that trophozoites of enviromnental protozoa might be carrier of mycobacteria and possibly M. bovis. An infection with bacilli-containing trophozoites might therefore be a potential route of transmission between the enviromnent and animals.

Styles APA, Harvard, Vancouver, ISO, etc.

Moreno, Ana Maria Biotechnology &amp Biomolecular Sciences Faculty of Science UNSW. « Understanding bacteria-protozoa interactions : from grazing resistance mechanisms to carbon flow in bacteria-protozoa food webs ». Publisher:University of New South Wales. Biotechnology & ; Biomolecular Sciences, 2008. http://handle.unsw.edu.au/1959.4/41446.

Texte intégral

Résumé :

Bacteria-protozoa interactions are one of the oldest between prokaryotic and eukaryotic organisms. As such, their study offers a unique opportunity to understand the different relationships that have evolved between them, including pathogenesis, and how their interaction can affect some important processes, such as wastewater treatment. In the first part of the work described here, the grazing defence mechanisms employed by Pseudomonas aeruginosa against the surface grazer, Acanthamoeba castellanii, were investigated. P. aeruginosa cells from early logarithmic growth and stationary phase were found to use different defence strategies. The type-III secretion system (T3SS) was found to be responsible for cytotoxicity of early logarithmic growth cells against A. castellanii. Of the three exotoxins produced by P. aeruginosa PA99, the phospholipase ExoU was found to make the greatest contribution to bacterial toxicity against the amoebae. Interestingly, a PA99null mutant that does not produce any known exotoxins but synthesises a secretion apparatus, was also found to be toxic to the amoeba, suggesting that the T3SS was being used to translocate other unknown toxins. Quorum sensing regulated virulence factor production was found to be involved in the grazing defence response of stationary phase P. aeruginosa cells. A. castellanii was found to be most susceptible to hydrogen cyanide and elastase produced during late logarithmic and stationary phase. In the second part, a stable isotope probing method was developed to investigate carbon flow through bacteria-protozoa food webs in activated sludge. The method was subsequently used to track carbon from bicarbonate and acetate through bacteria-orotozoa food webs under ammonia oxidising and nitrate reducing conditions. It was found that the Peritrich ciliate Campanella umbellaria, dominated the acquisition of carbon from bacteria with access to CO2 under ammonia oxidising conditions. Thus it appears that some of these bacteria must live in the plankton, as C. umbellaria is a filter feeder. No specific protozoan groups were found to dominate carbon acquisition from bacteria with access to acetate, under nitrate reducing conditions, probably due to label dilution. Overall the results presented here showed how bacteria-protozoa interactions have shaped infectious processes in higher eukaryotes, and the dynamics of carbon flow in activated sludge.

Styles APA, Harvard, Vancouver, ISO, etc.

O'Donoghue, Peter John. « Characterization of parasitic protozoa in Australia / ». [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe.pdf.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Hillman, K. « Studies on metabolism in rumen protozoa ». Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378375.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Glücksman, Edvard. « Taxonomy, biodiversity, and ecology of Apusozoa (Protozoa) ». Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:b96f9e28-e7ea-494a-9dad-bcb844e28c53.

Texte intégral

Résumé :

Apusozoa (Protozoa) is a phylum of heterotrophic gliding zooflagellates of unknown taxonomic affiliation, commonly observed in environmental samples. Almost nothing was previously known about the diversity and ecology of apusozoan species though, as bacterivores, they are probably important functional constituents within microbial assemblages. We explored apusozoan morphological and genetic diversity, ecology, and related methodological questions. By culturing environmental material from a range of habitats, we isolated and maintained monocultures of both previously described apusozoan orders, Apusomonadida (apusomonads) and Planomonadida (planomonads). For planomonads, we present a revised taxonomy based on morphology, ultrastructure, and 18S rDNA genetic differences. We describe nine new species and new genera Nutomonas and Fabomonas, and demonstrate ITS2 rDNA secondary structure analysis for species delineation. During our culturing effort, we also isolated two genotypes of a previously unknown flagellate group, shown here to belong to a novel third apusozoan order, Mantamonadida. We designed molecular probes specific to all three orders and applied them to environmental DNA, detecting novel 18S and ITS1 rDNA lineages in a range of habitats. We mined publically available metagenomic and metatranscriptomic sequence databases using 18S rDNA of described species as seeds, identifying hundreds of sequences with affinities to all three orders. Phylogenies featuring newly retrieved lineages with previously described species suggest that direct sequencing of transcriptomic material is more effective than amplification-dependent methods at detecting rare cells in mixed microbial assemblages. Finally, to test potential future applications of our newly isolated strains, we ran microcosm experiments examining the effect of protozoan (Cercozoa) grazing on the structure of bacterial assemblages, demonstrating that closely related and morphologically similar species can have different impacts on their prey base. Taken together, by combining traditional culturing and modern molecular methods, this thesis drastically improves our understanding of apusozoan diversity and sets the scene for future work using next-generation sequencing and ecologically driven functional experiments.

Styles APA, Harvard, Vancouver, ISO, etc.

Broomhead, Yvette. « The effects of enteric protozoa in turkeys / ». Free to MU Campus, others may purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1421120.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Livres sur le sujet "Protozoa"

Bhatia, B. B. Protozoa and protozoan diseases of domestic livestock. New Delhi : Directorate of Information and Publications of Agriculture, Indian Council of Agricultural Research, 2001.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

F, Smith Deborah, et Parsons Marilyn, dir. Molecular biology of parasitic protozoa. Oxford : IRL Press at Oxford University Press, 1996.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kreier, J. P., et J. R. Baker. Parasitic Protozoa. Dordrecht : Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-011-6847-2.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

1926-, Kreier Julius P., dir. Parasitic protozoa. 2^e éd. San Diego : Academic Press, 1993.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

P, Kreier Julius, et Baker John R, dir. Parasitic protozoa. 2^e éd. San Diego : Academic Press, 1991.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

F, Darbyshire J., dir. Soil protozoa. Wallingford, UK : CAB International, 1994.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

R, Baker John, dir. Parasitic protozoa. Boston : Allen & Unwin, 1987.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

1926-, Kreier Julius P., dir. Parasitic protozoa. 2^e éd. San Diego : Academic Press, 1993.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

1919-, Salfelder Karlhanns, et Sauerteig Eberhard, dir. Protozoan infections in man : Color atlas. Stuttgart : Schwer Verlag, 1988.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

1919-, Salfelder Karlhanns, et Sauerteig Eberhard, dir. Protozoan infections in man : Colour atlas. Stuttgart : Schwer, 1988.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Chapitres de livres sur le sujet "Protozoa"

Cole, Theodor C. H. « I. Protozoa – Protozoen – Protozoans ». Dans Wörterbuch der Wirbellosen / Dictionary of Invertebrates, 1–2. Berlin, Heidelberg : Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-52869-3_1.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lamorte, Dani. « Protozoa ». Dans Microbium, 113–28. Earth, Milky Way : punctum books, 2023. http://dx.doi.org/10.53288/0396.1.09.

Texte intégral

Résumé :

It could be in your eye or on a gallery floor. It seems like it’s under the microscope, but maybe it’s all in your head. The protozoa isn’t lurking exactly, but it’s a trick to find. This entry follows the slippery protozoa as it moves in animal bodies, along the edges of a painting, down the side of a sculpture. Georges Bataille’s writing on “formless” meets Lynda Benglis’ floor-pour paintings and Anne Truitt’s columns, leading us to ask: What other dreams will we find if we let protozoan indeterminacy undo us a little, loosen the knot of our being?

Styles APA, Harvard, Vancouver, ISO, etc.

Grossman, Marc E., Lindy P. Fox, Carrie Kovarik et Misha Rosenbach. « Protozoa ». Dans Cutaneous Manifestations of Infection in the Immunocompromised Host, 191–205. New York, NY : Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-1578-8_9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Brack, Manfred. « Protozoa ». Dans Agents Transmissible from Simians to Man, 288–332. Berlin, Heidelberg : Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71911-0_6.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Despommier, Dickson D., et John W. Karapelou. « Protozoa ». Dans Parasite Life Cycles, 1–39. New York, NY : Springer New York, 1987. http://dx.doi.org/10.1007/978-1-4612-3722-8_1.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Javor, Barbara. « Protozoa ». Dans Brock/Springer Series in Contemporary Bioscience, 159–62. Berlin, Heidelberg : Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-74370-2_11.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Ingham, Elaine R. « Protozoa ». Dans SSSA Book Series, 491–515. Madison, WI, USA : Soil Science Society of America, 2018. http://dx.doi.org/10.2136/sssabookser5.2.c23.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Milgroom, Michael G. « Protozoa ». Dans Biology of Infectious Disease, 71–87. Cham : Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-38941-2_6.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Gooch, Jan W. « Protozoa ». Dans Encyclopedic Dictionary of Polymers, 918. New York, NY : Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_14604.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Clauss, Wolfgang, et Cornelia Clauss. « Protozoa ». Dans Taschenatlas Zoologie, 198–205. Berlin, Heidelberg : Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-61593-5_21.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Protozoa"

Zhao, Hongzhou, Arrvindh Shriraman, Snehasish Kumar et Sandhya Dwarkadas. « Protozoa ». Dans the 40th Annual International Symposium. New York, New York, USA : ACM Press, 2013. http://dx.doi.org/10.1145/2485922.2485969.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

McCaffrey, James D. « Simulated protozoa optimization ». Dans 2012 IEEE 13th International Conference on Information Reuse & Integration (IRI). IEEE, 2012. http://dx.doi.org/10.1109/iri.2012.6303008.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Safiullin, R. T. « EPIZOOTIC SITUATION ON CONTAMINATION OF ENVIRONMENTAL OBJECTS WITH INFECTIVE ELEMENTS IN PIG FARMING ENTERPRISES ». Dans THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.344-350.

Texte intégral

Résumé :

The study of the epizootic situation on contamination of environmental objects with infective elements in pig farming enterprises of the Moscow and Kaluga Regions showed their contamination with parasitic protozoa oocysts and cysts and nematode eggs and larvae, which was influenced by the infection of livestock with such parasites, and quality of veterinary and sanitary, and therapeutic and preventive measures. According to the contamination degree with infective elements of parasitic protozoa and nematodes, the external environment objects in sow houses and nursing piglet sites were milking bail floors and passages, as well as feeders. The milking bail walls were least contaminated with parasitic protozoa oocysts and cysts and helminth eggs and larvae. In the studied commercial pig farming enterprises, the epizootic process for parasitic protozoa: cryptosporidia, isospores, Eimeria and Balantidium, was constantly active due to the presence of all epizootic process components: the source of invasion was infected animals; vectors were environmental objects contaminated with infective elements and susceptible animals, especially piglets.

Styles APA, Harvard, Vancouver, ISO, etc.

Pho, Khoa, Muhamad Kama Mohammed Amin et Atsuo Yoshitaka. « Segmentation-Driven RetinaNet for Protozoa Detection ». Dans 2018 IEEE International Symposium on Multimedia (ISM). IEEE, 2018. http://dx.doi.org/10.1109/ism.2018.00062.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Safiullin, R. T., S. K. Shibitov et R. R. Safiullin. « EPIZOOTIC SITUATION ON THE CONTAMINATION OF ENVIRONMENTAL OBJECTS WITH INVASIVE ELEMENTS ON THE CATTLE FARM OF THE MOSCOW REGION ». Dans THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.420-425.

Texte intégral

Résumé :

The study of the epizootic situation on the contamination of environmental objects with invasive elements on the livestock farm of the Moscow Region showed its contamination with parasitic protozoa oocysts and cysts, and helminth eggs and larvae which was directly affected by infection of the livestock with the above parasites and the quality of therapeutic and prophylactic and veterinary and sanitary measures. The objects of the external environment most contaminated with invasive elements of parasitic protozoa and helminths were the floor of stalls and passages in the premises for keeping animals. The stall walls and animal feeders were less contaminated with parasitic protozoa oocysts and cysts or helminth eggs or larvae. It should be noted that, the epizootic process for parasitic protozoa: Buxtonella, Cryptosporidium, Eimeria and Strongylata of the digestive tract, was permanent on the examined livestock farm of the Moscow Region, since all of its components were in place: the source of invasion was infected animals; transmission factors were environmental objects contaminated with invasive elements and susceptible animals, especially young animals. An analysis was performed of the plan of preventive antiepizootic measures of this farm in relation to parasitic diseases in terms of diagnostic tests for parasitosis, and therapeutic-and-prophylactic and veterinary-sanitary treatments.

Styles APA, Harvard, Vancouver, ISO, etc.

Itoh, A. « Motion control of protozoa for bio MEMS ». Dans 1999 IEEE/ASME International Conference on Advanced Intelligent Mechatronics. IEEE, 1999. http://dx.doi.org/10.1109/aim.1999.803138.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Itoh, A. « Motion control of protozoa for bio mems ». Dans 1999 IEEE/ASME International Conference on Advanced Intelligent Mechatronics. IEEE, 1999. http://dx.doi.org/10.1109/aim.1999.803267.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kuznetsova, E. Ch. « CLINICAL CASE OF EMERIOSIS IN A PIG ». Dans DIGEST OF ARTICLES ALL-RUSSIAN (NATIONAL) SCIENTIFIC AND PRACTICAL CONFERENCE "CURRENT ISSUES OF VETERINARY MEDICINE : EDUCATION, SCIENCE, PRACTICE", DEDICATED TO THE 190TH ANNIVERSARY FROM THE BIRTH OF A.P. Stepanova. Publishing house of RGAU - MSHA, 2021. http://dx.doi.org/10.26897/978-5-9675-1853-9-2021-43.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

« Metagenomic search for the protozoa in atherosclerotic plaques ». Dans SYSTEMS BIOLOGY AND BIOINFORMATICS. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 2019. http://dx.doi.org/10.18699/sbb-2019-45.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Mann Kyoon Shin. « Phylogenetic reconstruction of hypotrichous ciliates (protozoa, ciliophora, hypotrichida) ». Dans Proceedings. The 9th Russian-Korean International Symposium on Science and Technology. KORUS 2005. IEEE, 2005. http://dx.doi.org/10.1109/korus.2005.1507693.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Protozoa"

McElwain, Terry F., Eugene Pipano, Guy H. Palmer, Varda Shkap, Stephn A. Hines et Wendy C. Brown. Protection of Cattle against Babesiosis : Immunization against Babesia bovis with an Optimized RAP-1/Apical Complex Construct. United States Department of Agriculture, septembre 1999. http://dx.doi.org/10.32747/1999.7573063.bard.

Texte intégral

Résumé :

Previous research and current efforts at control of babesiosis fall short of meeting the needs of countries where the disease is endemic, such as Israel, as well as the needs of exporting countries and countries bordering on endemic areas, such as the U.S. Our long-term goal is to develop improved methods of immunization against bovine babesiosis based on an understanding of the molecular mechanisms of immune protection and parasite targets of a protective immune response. In our previous BARD project, we established the basis for focusing on rhoptry antigens as components of a subunit vaccine against bovine babesiosis, and for additional research to better characterize rhoptry associated protein-1 (RAP-1) as a target of protective immunity. In this continuation BARD project, our objectives were to [1] optimize the immune response against RAP-1, and [2] identify additional rhoptry candidate vaccine antigens. The entire locus encoding B. bovis RAP-1 was sequenced, and the rap-1 open reading frame compared among several strains. Unlike B. bigemina, in which multiple gene copies with variant domains encode RAP-1, the B. bovis RAP-1 locus contains only two identical genes which are conserved among strains. Through testing of multiple truncated constructs of rRAP-1, one or more immunodominant T cell epitopes were mapped to the amino terminal half of RAP-1. At least one linear and one conformational B cell epitope have been demonstrated in the same amino terminal construct, which in B. bigemina RAP-1 also contains an epitope recognized by neutralizing antibody. The amine terminal half of the molecule represents the most highly conserved part of the gene family and contains motifs conserved broadly among the apicomplexa. In contrast, the carboxy terminal half of B. bovis RAP-1 is less well conserved and contains multiple repeats encoding a linear B cell epitope potentially capable of inducing an ineffective, T cell independent, type 2 immune response. Therefore, we are testing an amino terminal fragment of RAP-1 (RAP-1N) in an immunization trial in cattle. Cattle have beer immunized with RAP-1N or control antigen, and IL-12 with Ribi adjuvant. Evaluation of the immune response is ongoing, and challenge with virulent B. bovis will occur in the near future. While no new rhoptry antigens were identified, our studies did identify and characterize a new spherical body antigen (SBP3), and several heat shock proteins (HSP's). The SBP3 and HSP21 antigens stimulate T cells from immune cattle and are considered new vaccine candidates worthy of further testing. Overall, we conclude that a single RAP-1 vaccine construct representing the conserved amino terminal region of the molecule should be sufficient for immunization against all strains of B. bovis. While results of the ongoing immunization trial will direct our next research steps, results at this time are consistent with our long term goal of designing a subunit vaccine which contains only the epitopes relevant to induction of protective immunity. Parallel studies are defining the mechanisms of protective immunity. Apicomplexan protozoa, including babesiosis and malaria, cause persistent diseases for which control is inadequate. The apical organelles are defining features of these complex protozoa, and have been conserved through the evolutionary process, Past and current BARD projects on babesiosis have established the validity and potential of exploiting these conserved organelles in developing improved control methods applicable to all apicomplexan diseases.

Styles APA, Harvard, Vancouver, ISO, etc.

Gillor, Osnat, Stefan Wuertz, Karen Shapiro, Nirit Bernstein, Woutrina Miller, Patricia Conrad et Moshe Herzberg. Science-Based Monitoring for Produce Safety : Comparing Indicators and Pathogens in Water, Soil, and Crops. United States Department of Agriculture, mai 2013. http://dx.doi.org/10.32747/2013.7613884.bard.

Texte intégral

Résumé :

Using treated wastewater (TWW) for crop irrigation represents an important opportunity for ensuring adequate food production in light of growing freshwater scarcity worldwide. However, the environmentally sustainable approach of using TWW for irrigation can lead to contamination of produce with fecal pathogens that may remain in treated water. The overall goal of this research was to evaluate the correlation between the presence of fecal indicator bacteria (FIB) and that of a suite of human pathogens in TWW, the irrigated soil, and crops. Field experiments were conducted to compare secondary and tertiary TWW with dechlorinated tap water for irrigation of tomatoes, a typical commercial crop, in Israel, a semi-arid country. Human pathogens including bacteria (Salmonella), protozoa (Cryptosporidiumand Giardia), and viruses (Adenovirus [AV Types A, B, C & 40/41] and Enterovirus [EV71 subtypes]) were monitored in two field trials using a combination of microscopic, cultivation-based, and molecular (qPCR) techniques. Results from the field trials indicate that microbial contamination on the surface of tomatoes did not appear to be associated with the source of irrigated waters; FIB contamination was not statistically different on tomatoes irrigated with TWW as compared to tomatoes irrigated with potable water. In fact, Indicator bacteria testing did not predict the presence of pathogens in any of the matrices tested. High concentrations of FIB were detected in water and on tomato surfaces from all irrigation treatment schemes, while pathogen contamination on tomato surfaces (Cryptosporidiumand Salmonella) was only detected on crops irrigated with TWW. These results suggest that regular monitoring for pathogens should take place to accurately detect presence of harmful microorganisms that could threaten consumer safety. A notable result from our study is that the large numbers of FIB in the water did not appear to lead to FIB accumulation in the soil. With the exception of two samples, E. coli that was present at 10³ to 10⁴ cells/100 mL in the water, was not detected in the soil. Other bacterial targets associated with the enteric environment (e. g., Proteusspp.) as well as protozoal pathogens were detected in the TWW, but not in the soil. These findings suggest that significant microbial transfer to the soil from TWW did not occur in this study. The pattern of FIB contamination on the surfaces of tomatoes was the same for all treatment types, and showed a temporal effect with more contamination detected as the duration of the field trial increased. An important observation revealed that water quality dramatically deteriorated between the time of its release from the wastewater treatment plant and the time it was utilized for irrigation, highlighting the importance of performing water quality testing throughout the growing season at the cultivation site.

Styles APA, Harvard, Vancouver, ISO, etc.

Allende López, Marcos, et Adrián Pareja. Open configuration options GAS Distribution Protocol for Permissioned-Public Ethereum-Based Blockchain Networks. Sous la direction de Alejandro Pardo et Mariana Gutierrez. Inter-American Development Bank, mai 2022. http://dx.doi.org/10.18235/0004243.

Texte intégral

Résumé :

This paper presents a protocol to manage decentralized access and use of Permissioned Public Blockchain Networks using Ethereum technology as the underlying protocol. It proposes a solution to avoid DDOS and enforce accountability while eliminating transaction fees. The protocol has been tested and implemented in the LACChain Blockchain Networks.

Styles APA, Harvard, Vancouver, ISO, etc.

Browdy, Craig, et Esther Lubzens. Cryopreservation of Penaeid Shrimp Embryos : Development of a Germplasm Cryo-Bank for Preservation of High Health and Genetically Improved Stocks. United States Department of Agriculture, août 2002. http://dx.doi.org/10.32747/2002.7695849.bard.

Texte intégral

Résumé :

The objectives of the project were to develop a successful protocol for cryopreservation of penaeid germ plasm in order to preserve a pathogen-free broodstock nucleus for commercial exploitation of marine shrimp in aquaculture. The critical parameters to be characterized in the project were: 1. Determination of chill sensitivity and chill tolerant embryonic stages, including a full description and time course study of embryonic developmental stages. 2. Development of protocols for loading and removal of cryoprotectant agents (CPAs) from embryos; determination of optimal concentrations and duration of loading. 3. Characterization of the toxicity of the selected CP As and 4. Establishing optimal cooling and thawing procedures. Studies were performed on two penaeid species: Litopenaeus vannamei (in the USA) and P. semisulcatus (in Israel). The effect of incubation temperature on embryonic development rate and hatching success was studied in L. vannamei, showing that spawns maybe maintained at temperatures ranging from 24°C to 30°C, without compromising hatchability. Embryonic development extends from 12 hr to 19 hr at 30°C and 24°C, respectively. Studies showed that advanced embryonic developmental stages were chill tolerant in the two studied species, but P. semisulcatus could better endure lower temperatures than L. vannamei. A large number of experiments were performed to determine the optimal CP As, their concentration and duration of loading. Permeating (e.g. glycerol, methanol, DMSO, 1,2- propanediol, ethylene glycol, glucose) and non-permeating CPAs (sucrose, PVP, polyethylene glycol) were tested and several combinations of permeating and non-permeating CP As, on fertilized eggs (embryos), nauplii and protozoeae. In general, nauplii tolerated higher CPA concentrations than eggs and nauplii were also more permeable to radiolabeled methanol. Chlorine treatment intended to remove the chitinous envelop from eggs, did not increase dramatically the permeation of radiolabled methanol into eggs. Cooling eggs, nauplii or protozoeae to cryogenic temperatures, by either vitrification or slow cooling protocols, did not result in full survival of thawed samples, despite exhaustive attempts testing various protocols and CP As. Results seemed more encouraging in freezing of nauplii in comparison to eggs or protozoeae. Successful preliminary results in cryopreservation of spermatozoa of P. vannamei, will facilitate preservation of genetic specific to some extent.

Styles APA, Harvard, Vancouver, ISO, etc.

Kowalski, Angel. PR-186-163606-R01 Establishing the Potential Severity of Various Cathodic Protection Shielding Parameters. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), novembre 2018. http://dx.doi.org/10.55274/r0011534.

Texte intégral

Résumé :

A semi-quantitative scoring protocol was developed to identify pipeline systems with the highest relative susceptibility to coating CP shielding. The scoring protocol takes into consideration the type of coatings, surface preparation, types of soils, weather conditions and pipeline characteristics. The protocol was tested over pipeline cases provided by pipeline operators. The users are encouraged to use the scoring protocol to screen, prioritize pipeline systems susceptible to coating CP shielding, and collect critical data in order to improve the performance of the tool with the goal to minimize the impact of this threat on the integrity of their pipelines. Guidelines have been provided to help the users of the protocol improve the monitoring, inspection and mitigation of external metal loss due to coating CP shielding.

Styles APA, Harvard, Vancouver, ISO, etc.

Beavers et Johnson. L51871 SCC Field Data Collection. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), janvier 2000. http://dx.doi.org/10.55274/r0011178.

Texte intégral

Résumé :

The original objectives of PRCI project PR 186-9506 were: (1) to establish a standard protocol for the collection of field data on SCC, (2) to instruct field engineers and technicians from the pipeline companies to insure that the protocol is used properly, and (3) to establish and maintain a data base for the compilation and analysis of the field data. The program was divided into three Tasks: Task 1 - Protocol Development, Task 2 - Protocol Training, and Task 3 - Data Base Development and Management. In the final scope of work, the PRCI Committee canceled Task 3 of the project.

Styles APA, Harvard, Vancouver, ISO, etc.

Hanson et McNealy. PR-366-083506-R01 Guidelines for In Situ Characterization of Cracks. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), décembre 2010. http://dx.doi.org/10.55274/r0010736.

Texte intégral

Résumé :

The purpose of this project was to establish a practical metallographic protocol to distinguish between high pH SCC and near-neutral pH SCC in the ditch. The protocol addresses how to distinguish the crack propagation modes. In addition, the protocol addresses procedures for preparation of sample location areas for analysis through the use of mechanical, electrical, and chemical means considering the quality of results, ease of use, portability, and reliability.

Styles APA, Harvard, Vancouver, ISO, etc.

Eiber et Leis. L51864 Protocol to Prioritize Sites for High-pH Stress Corrosion Cracking on Gas Pipelines. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), septembre 1998. http://dx.doi.org/10.55274/r0011209.

Texte intégral

Résumé :

This program developed a stress-corrosion cracking (SCC) protocol for use in assessing the likelihood of the conditions necessary for high pH SCC on individual pipeline segments and an SCC integrity management plan to assist operators in selecting appropriate remedial actions depending on whether SCC is located and the potential consequences. This protocol was developed as a conservative guideline based on existing knowledge at the time of development. This high pH SCC protocol was validated using data from 15 SCC service incidents collected during the conduct of this program and three test cases on pipelines without SCC available from another SCC protocol. An SCC Likelihood Index was developed that provides index values from 40 to 140.

Styles APA, Harvard, Vancouver, ISO, etc.

Rose, Sara, Laura Baumann, Patrick Emblidge, Jeffrey Lonneker, Nadja Schmidt, Thomas Rodhouse et Beth Ward. Protocol implementation plan for national parks in the Pacific Northwest, North American Bat Monitoring Program for surveying summertime bat occurrence with stationary deployments of echolocation recording devices : Version 1.0. National Park Service, 2024. http://dx.doi.org/10.36967/2301735.

Texte intégral

Résumé :

he Northwestern Hub for Bat Population Research and Monitoring (NW Bat Hub), as part of the North American Bat Monitoring Program (NABat), developed a regional protocol (Rodriguez et al. 2019) to guide multi-agency collaborative implementation of summertime acoustic surveys to track the status and trends of bat populations. See Loeb et al. (2015) and Reichert et al. (2021) for a description of the full NABat plan including winter bat colony counting. The protocol provides guidance specifically for parks in the National Park Service (NPS) North Coast Cascades, Upper Columbia Basin, and Klamath Networks. This protocol implementation plan (PIP) outlines how the protocol will be implemented by NW Bat Hub and National Park staff within this three-network/three-state (Washington, Oregon, Idaho) region. Specific topics for NPS implementation of the protocol that require additional details beyond those outlined by Rodriguez et al. (2019) are the specific NPS requirements for data management, analysis, reporting, and a budget for NPS to contribute to long-term sustainability of the NW Bat Hub and protocol implementation. Surveys will be conducted on and adjacent to NPS lands collaboratively by NPS and NW Bat Hub staff. Roles and responsibilities for protocol implementation with be established prior to each field season depending on staff capacities and interests. This PIP is versionable and it will be updated periodically alongside updates to the protocol itself, and as other operational changes are made. The PIP serves to document why and how NPS will engage as an NABat partner in the Pacific Northwest and with the national NABat program led by US Geological Survey Fort Collins Science Center (USGS-FORT), the role of summertime acoustic monitoring as a way for NPS to meet its vital signs monitoring goals for bats (Garrett et al. 2007), the stewardship of acoustic data by NW Bat Hub and USGS-FORT on behalf of NPS, and the Hub?s role as a source of coordinated conservation expertise for NPS and other regional collaborators. This PIP contains a detailed overview of how the protocol will be used in National Park units in the Pacific Northwest. It is intended for use by NPS and NW Bat Hub coordinators and team leaders, program administrators, field crew leads, and data analysts who need to be conversant in the details of the program. Standard operating procedures that detail the operational-level information can be located in the protocol narrative by Rodriguez et al. (2019).

Styles APA, Harvard, Vancouver, ISO, etc.

Cheriton, D. R. VMTP : Versatile Message Transaction Protocol : Protocol specification. RFC Editor, février 1988. http://dx.doi.org/10.17487/rfc1045.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!