Academic literature on the topic 'Ciliats'
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Journal articles on the topic "Ciliats"
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IGLESIAS, R., A. PARAMÁ, M. F. ÁLVAREZ, J. LEIRO, F. M. UBEIRA, and M. L. SANMARTÍN. "Philasterides dicentrarchi (Ciliophora: Scuticociliatida) expresses surface immobilization antigens that probably induce protective immune responses in turbot." Parasitology 126, no. 2 (February 2003): 125–34. http://dx.doi.org/10.1017/s0031182002002688.
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Philasterides dicentrarchi is a histophagous ciliate causing systemic scuticociliatosis in cultured turbot. This study demonstrates that turbot which survive this disease have serum antibodies that recognize ciliary antigens of this ciliate in ELISA and immobilize/agglutinate the ciliate in vitro. Mouse sera raised against ciliary antigens and integral membrane proteins are likewise capable of immobilizing/agglutinating the ciliates, indicating that P. dicentrarchi, like other ciliates, expresses surface immobilization antigens. Furthermore, the antigen agglutinating reaction induces the parasite to shed its surface antigens rapidly, replacing them with others with different specific serology. This antigen shedding and variation response is similar to that detected in other protozoan parasites. Immunization of turbot with ciliate lysate plus adjuvant or with formalin-fixed ciliates induced synthesis of agglutinating antibodies and conferred a degree of protection against challenge infection, suggesting that the response to surface antigens may play an important role in defence against this pathogen, SDS–PAGE and immunoblotting studies indicated the existence of a predominant polypeptide of about 38 kDa in the ciliary antigen and membrane protein fractions, and this may be the principal surface antigen of P. dicentrarchi.
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Ohmura, Takuya, Yukinori Nishigami, Atsushi Taniguchi, Shigenori Nonaka, Junichi Manabe, Takuji Ishikawa, and Masatoshi Ichikawa. "Simple mechanosense and response of cilia motion reveal the intrinsic habits of ciliates." Proceedings of the National Academy of Sciences 115, no. 13 (March 12, 2018): 3231–36. http://dx.doi.org/10.1073/pnas.1718294115.
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An important habit of ciliates, namely, their behavioral preference for walls, is revealed through experiments and hydrodynamic simulations. A simple mechanical response of individual ciliary beating (i.e., the beating is stalled by the cilium contacting a wall) can solely determine the sliding motion of the ciliate along the wall and result in a wall-preferring behavior. Considering ciliate ethology, this mechanosensing system is likely an advantage in the single cell’s ability to locate nutrition. In other words, ciliates can skillfully use both the sliding motion to feed on a surface and the traveling motion in bulk water to locate new surfaces according to the single “swimming” mission.
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Ishikawa, Takuji, Tomoyuki Tanaka, Yohsuke Imai, Toshihiro Omori, and Daiki Matsunaga. "Deformation of a micro-torque swimmer." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2185 (January 2016): 20150604. http://dx.doi.org/10.1098/rspa.2015.0604.
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The membrane tension of some kinds of ciliates has been suggested to regulate upward and downward swimming velocities under gravity. Despite its biological importance, deformation and membrane tension of a ciliate have not been clarified fully. In this study, we numerically investigated the deformation of a ciliate swimming freely in a fluid otherwise at rest. The cell body was modelled as a capsule with a hyperelastic membrane enclosing a Newtonian fluid. Thrust forces due to the ciliary beat were modelled as torques distributed above the cell body. The effects of membrane elasticity, the aspect ratio of the cell's reference shape, and the density difference between the cell and the surrounding fluid were investigated. The results showed that the cell deformed like a heart shape, when the capillary number was sufficiently large. Under the influence of gravity, the membrane tension at the anterior end decreased in the upward swimming while it increased in the downward swimming. Moreover, gravity-induced deformation caused the cells to move gravitationally downwards or upwards, which resulted in a positive or negative geotaxis-like behaviour with a physical origin. These results are important in understanding the physiology of a ciliate's biological responses to mechanical stimuli.
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Wan, Kirsty Y., Sylvia K. Hürlimann, Aidan M. Fenix, Rebecca M. McGillivary, Tatyana Makushok, Evan Burns, Janet Y. Sheung, and Wallace F. Marshall. "Reorganization of complex ciliary flows around regenerating Stentor coeruleus." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1792 (December 30, 2019): 20190167. http://dx.doi.org/10.1098/rstb.2019.0167.
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The phenomenon of ciliary coordination has garnered increasing attention in recent decades and multiple theories have been proposed to explain its occurrence in different biological systems. While hydrodynamic interactions are thought to dictate the large-scale coordinated activity of epithelial cilia for fluid transport, it is rather basal coupling that accounts for synchronous swimming gaits in model microeukaryotes such as Chlamydomonas. Unicellular ciliates present a fascinating yet understudied context in which coordination is found to persist in ciliary arrays positioned across millimetre scales on the same cell. Here, we focus on the ciliate Stentor coeruleus , chosen for its large size, complex ciliary organization, and capacity for cellular regeneration. These large protists exhibit ciliary differentiation between cortical rows of short body cilia used for swimming, and an anterior ring of longer, fused cilia called the membranellar band (MB). The oral cilia in the MB beat metachronously to produce strong feeding currents. Remarkably, upon injury, the MB can be shed and regenerated de novo. Here, we follow and track this developmental sequence in its entirety to elucidate the emergence of coordinated ciliary beating: from band formation, elongation, curling and final migration towards the cell anterior. We reveal a complex interplay between hydrodynamics and ciliary restructuring in Stentor , and highlight for the first time the importance of a ring-like topology for achieving long-range metachronism in ciliated structures. This article is part of the Theo Murphy meeting issue ‘Unity and diversity of cilia in locomotion and transport’.
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ELLOUMI, J., Z. DRIRA, A. HAMZA, and H. AYADI. "Space-time variation of ciliates related to environmental factors in 15 nearshore stations of the Gulf of Gabes." Mediterranean Marine Science 16, no. 1 (July 22, 2014): 162. http://dx.doi.org/10.12681/mms.792.
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Diversity and structure of ciliate communities in the Gulf of Gabes (Tunisia) were investigated based on a survey of 15 nearshore stations along 237 Km, by monthly sampling over a 1-year. Ciliated protozoa were identified to genus and/or species level and enumerated. Statistic tools were used to explain the ciliates assemblage. High ciliates species richness from 133 taxa was recorded, including new records of 76 species. This study showed a longitudinal distribution of ciliate communities, which are organized in northern stations (from Tabia to Harbor of Gabes) and southern stations (from Zarrat to Jabiat Haj Ali). The number of taxa increased significantly in northern stations but decreased in the southern. This distribution was mainly influenced by the salinity and phytoplankton abundance. Ciliate taxa were grouped into fives size-classes: 15-30 µm, 30-50 µm, 50-100 µm, 100-200 µm and >200 µm. In terms of abundance, most abundant size groups were small ciliates (15-30 μm) accounted from 15 to 79 %, while the greatest biomass contribution came from the 50-100 μm size classes. We thus conclude high diversity of ciliates communities that showed a geographical distribution influenced by abiotic and biotic factors along the coast of Gulf of Gabes.
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Decamp, O., A. Warren, and R. Sanchez. "The Role of Ciliated Protozoa in Subsurface Flow Wetlands and their Potential as Bioindicators." Water Science and Technology 40, no. 3 (August 1, 1999): 91–98. http://dx.doi.org/10.2166/wst.1999.0143.
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The role of ciliated protozoa in the root zone method of wastewater treatment was assessed by analyzing ciliate community structure in four experimental subsurface flow wetlands (planted or unplanted in either soil or gravel) and estimating Escherichia coli removal due to ciliate predation. A total of 22 different ciliate taxa were isolated from the four reed beds. The first third of each bed contained a higher abundance and diversity than the final third of the bed. There was a qualitative correlation between physicochemical conditions and ciliate community structure: microaerophilic species dominated the organic-rich and oxygen-poor environment of the unplanted soil bed; aerobic and facultative bacterivorous species dominated the better oxygenated gravel beds; a combination of these two communities was found in the planted soil bed. The average grazing rates of ciliates was around 5 times higher in the planted gravel bed (49 bacteria/ciliate/hour) than in the unplanted soil bed (9.5 bacteria/ciliate/hour). Taking into account the retention time and ciliate abundance, it was calculated that ciliates, by their predatory activities, are capable of removing up to 2.35 × 105 and 0.45 × 105E. coli in the first third of the planted gravel bed and unplanted soil bed, respectively. These results are discussed in relation to variation in E. coli removal kinetics. The potential for using ciliate communities as indicators of conditions within constructed wetlands is also assessed.
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Mutazono, Masatoshi, Tomoko Noto, and Kazufumi Mochizuki. "Diversification of small RNA amplification mechanisms for targeting transposon-related sequences in ciliates." Proceedings of the National Academy of Sciences 116, no. 29 (July 1, 2019): 14639–44. http://dx.doi.org/10.1073/pnas.1903491116.
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The silencing of repetitive transposable elements (TEs) is ensured by signal amplification of the initial small RNA trigger, which occurs at distinct steps of TE silencing in different eukaryotes. How such a variety of secondary small RNA biogenesis mechanisms has evolved has not been thoroughly elucidated. Ciliated protozoa perform small RNA-directed programmed DNA elimination of thousands of TE-related internal eliminated sequences (IESs) in the newly developed somatic nucleus. In the ciliate Paramecium, secondary small RNAs are produced after the excision of IESs. In this study, we show that in another ciliate, Tetrahymena, secondary small RNAs accumulate at least a few hours before their derived IESs are excised. We also demonstrate that DNA excision is dispensable for their biogenesis in this ciliate. Therefore, unlike in Paramecium, small RNA amplification occurs before IES excision in Tetrahymena. This study reveals the remarkable diversity of secondary small RNA biogenesis mechanisms, even among ciliates with similar DNA elimination processes, and thus raises the possibility that the evolution of TE-targeting small RNA amplification can be traced by investigating the DNA elimination mechanisms of ciliates.
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Ito, Hiroaki, Toshihiro Omori, and Takuji Ishikawa. "Swimming mediated by ciliary beating: comparison with a squirmer model." Journal of Fluid Mechanics 874 (July 12, 2019): 774–96. http://dx.doi.org/10.1017/jfm.2019.490.
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The squirmer model of Lighthill and Blake has been widely used to analyse swimming ciliates. However, real ciliates are covered by hair-like organelles, called cilia; the differences between the squirmer model and real ciliates remain unclear. Here, we developed a ciliate model incorporating the distinct ciliary apparatus, and analysed motion using a boundary element–slender-body coupling method. This methodology allows us to accurately calculate hydrodynamic interactions between cilia and the cell body under free-swimming conditions. Results showed that an antiplectic metachronal wave was optimal in the swimming speed with various cell-body aspect ratios, which is consistent with former theoretical studies. Exploiting oblique wave propagation, we reproduced a helical trajectory, like Paramecium, although the cell body was spherical. We confirmed that the swimming velocity of model ciliates was well represented by the squirmer model. However, squirmer modelling outside the envelope failed to estimate the energy costs of swimming; over 90 % of energy was dissipated inside the ciliary envelope. The optimal swimming efficiency was given by the antiplectic wave; the value was 6.7 times larger than in-phase beating. Our findings provide a fundamental basis for modelling swimming micro-organisms.
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Jiang, Yong, Wei Zhang, Mingzhuang Zhu, Khaled A. S. Al-Rasheid, and Henglong Xu. "Are non-loricate ciliates a primary contributor to ecological pattern of planktonic ciliate communities? A case study in Jiaozhou Bay, northern China." Journal of the Marine Biological Association of the United Kingdom 92, no. 6 (March 28, 2012): 1301–8. http://dx.doi.org/10.1017/s0025315412000276.
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The contribution of non-loricate ciliate assemblage to the ecological pattern of a ciliated protozoan community was studied based on a 1-year (June 2007–May 2008) dataset collected from Jiaozhou Bay, northern China. Samples were collected biweekly from five sampling sites. Results showed that: (1) the non-loricate ciliate assemblages were the primary components and significantly correlated with the total ciliate communities in terms of species number, abundance and biomass; (2) the ecological pattern of non-loricate ciliate assemblages was significantly related to that of both total ciliate communities and variations in environmental variables; and (3) spatio-temporal variations in biodiversity (richness, diversity and evenness of species) indices of non-loricate ciliate assemblages were significantly correlated with those of total ciliate communities and the environmental conditions, especially nutrients nitrate nitrogen, nitrite nitrogen and soluble reactive phosphorous. These results suggest that the non-loricate ciliates are a primary contributor to the ecological pattern of total ciliate communities and might be used as a potential bioindicator for bioassessment in marine ecosystems.
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GÜRELLİ, GÖZDE, and ASEM RAMADAN AMAR MOHAMED. "Ciliated Protozoan Fauna in the Forestomach of Dromedary Camels (Camelus dromedarius) in Libya." Zootaxa 4434, no. 3 (June 18, 2018): 429. http://dx.doi.org/10.11646/zootaxa.4434.3.2.
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Species composition and distribution of ciliated protozoa obtained from the forestomach of 20 dromedary camels living in Zawiya, Libya were examined. Nineteen species and 10 morphotypes belonging to eight genera were identified. The mean number of ciliates was 54.2 ± 32.9 × 104 cells ml−1 in the forestomach contents, and the mean number of ciliate species per host was 6.5 ± 2.9. Entodinium and Epidinium were the main genera, as these ciliates were found consistently at higher proportions than those of the other genera. In contrast, Ophryoscolex and Polyplastron were only observed at low frequencies. Diplodinium rangiferi, Entodinium ellipsoideum, E. simulans, and Polyplastron multivesiculatum were new endosymbionts recorded from camels.
Dissertations / Theses on the topic "Ciliats"
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Salvadó, i. Cabré Humbert. "Estudi dels protozous ciliats en plantes de tractament biològic de les aigües residuals." Doctoral thesis, Universitat de Barcelona, 1990. http://hdl.handle.net/10803/821.
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La present memòria té com a principals objectius investigar sobre la relació dels diferents protozous ciliats vers els paràmetres d'enginyeria que s'utilitzen per al cootrol dels reactors biològics de fangs actius de les estacions depuradores d'aigües residuals, així com poder utilitzar els resultats obtinguts per al millorament del funcionament i control de les plantes depuradores d'aigües residuals. Per altra banda i per a comprendre els factors limitants dels reactors biològics s'estudien diversos tòxics, concretament s'efectua l'estudi en bioassatjos i s'han escollit dos metalls pesants (el Zinc i el Plom) i el Fenol. Posteriorment s'efectua l'estudi del Zinc en Planta Pilot. Alhora s'analitza també un control de les concentracions de metall en una planta pilot experimental i en una planta urbana. L'estudi es basa en els resultats de les anàlisis biològiques, físiques i químiques obtingudes en una planta pilot i en tres plantes depuradores urbanes durant un any.L'estudi dels microorganismes i específicament dels ciliats ens aporta informació en dos camps el de la sistemàtica, i ecologia de les espècies del sistema que constitueix els fangs actius i en el funcionament biològic de les plantes de fangs actius. L'estudi de les metodologies emprades en aquest camp ens ha portat a aprofundir-les per treure'n més informació. Hem elaborat noves metodologies i hem efectuat modificacions a d'altres ja existents. Destaquem els principals resultats i cooclusions obtinguts;
1) Es determinen faunísticameot 33 espècies de ciliats. El nombre d'espècies fixades al substrat és superior a les altres formes i cal destacar l'Ordre Peritrichida. En nombre d'individus els ordres Peritrichida i Hypotrichida són els més abundants i en algun cas l'abundàocia de l'ordre Scuticociliatid correspon a elevats creixements de Uronema marinum.
2) Es desenvolupa una equació matemàtica per tal de poder quantificar fàcilment els difernts tipus d'organismes filamentosos en viu i en fresc. Després de la realització de nombroses observacions s'ha arribat a la conclusió que existeix una relació molt estreta entre la longitud d'un segment i el nombre d'interseccions que s'obté creuant aquest segment amb una mostra de línies a l'atzar i independentment de la forma d'aquestes línies o filaments. S'obté que el nombre d'interseccions obtingudes és directament proporcional a la longitud total dels filaments d'una mostra.
3) Es desenvolupa un nou model d'enginyeria per tal de valorar l'edat dels fangs. L'estudi del citat model amb dades reals demostra la seva utilitat obtenint interessants resultats sobre la dinàmica de poblacions mentre augmenta l'edat dels fangs. S'obté que per sobre de 12 dies d'edat de fangs no hi ha augment de la concentració de ciliats.
En l'estudi de la relació entre els paràmetres físico-químics i les concentracions de protozous ciliats, el paràmetre que dóna un coeficient de correlació més elevat a nivell multivariant (múltiples espècies) i univariant (una sola espècie) és l'edat de fangs obtinguda a partir del model proposat.
4) S'estudia la variació de la velocitat de divisió cel.lular, el resultat del qual enfront a la concentració d'individus ens dóna un nou valor de judici, tant o més important per valorar la relació de les espècies amb un detenninat paràmetre i per poder trobar el rang òptim de desenvolupament de cada espècie. Es determina per a cada espècie estudiada la variació de la velocitat de divisió segons els següents paràmetres físico-químics: Oxigen dissolt, edat de fangs (a partir del model proposat), càrrega màssica i DBO, de decantador primari i secundari.
5) L'estudi de l'afinitat de les espècies de ciliats ens permet concloure que la interdependència que existeix respecte entre les espècies es efímera i canvia d'una estació a un altre. Per tant, les associacions trobades varien principalment segons els valors dels paràmetres físico-químics.
6) S'observa que existeix una relació inversament proporcional entre la diversitat específica dels ciliats i la càrrega màssica. Essent així els ciliats indicadors no tan sols de la qualitat de l'aigua tractada sinó de la qualitat de l'aigua que entra en el procés.
7) En l'estudi de la toxicitat del Zn s'observa que la seva disponibilitat pot variar al llarg del tractament. En l'efluent es produeix una redissolució del Zn, atribuïble molt probablement a la disminució de la matèria orgànica. La seva toxicitat indueix l'encistament d' Opercularia minima. Respecte el Pb s'observa que en les aigües residuas utilitzades precipita tot, i a 550 mg/l. màxima concentració testejada no es produeixen efectes tòxics.
8) La concentració d'oxígen dissolt és un dels principals factors que limiten la velocitat de creixement cel.lular dels ciliats, essent el gènere Vorticella el que necessita una concentració més elevada d'oxigen dissolt per sobre de 3 ppm per assolir una velocitat de divisió més elevada.
9) L'augment de la concentració de ciliats significa una reducció de la DBO, de l'efluent, si bé per disminuir-la per sota dels 15 ppm, ha d'augmentar molt el quocient (concentració de ciliats/càrrega màssica) respecte la DB05 de l'efluent, la corba que s'obté té una forma semblant a una exponencial inversa.
10) Es proposen unes taules estadístiques per relacionar els diferents organismes i els paràmetres d'enginyeria. La utilització de les quals optimitza el diagnòstic. Aquestes taules estadístiques es basen amb les dades obtingudes i s'obté per a cada concentració d'individus d'una espècie determinada un valor mitjà de cada paràmetre físico-químic estudiat. Per a cada valor mitjà també s'obté la seva variança, de forma que alhora de pronosticar un paràmetre físico-químic s'efectua la mitjana ponderada respecte la variança.
This thesis aims to study the relationship between protozoan ciliates and the engineering
parameters that are used in activated sludge wastewater treatment plants. The results may be used to improve the functioning and control of such plants. Furthermore, in order to understand the limiting factors in biological reactors, various toxics are studied: zinc, lead and phenol. The study is based on the results of biological, chemical and physical analyses obtained in a pilot plant and in three urban sewage treatment plants over one year. Methodological studies in this field have not only provided more information but have also helped in the modification and development of existing methods.
1) A mathematical equation bas been developed which will easily aid the counting the different kinds of filamentous organisms "in vivo".
2) A new engineering model bas been developed which will determine the MCRT. The study of this model with real data demonstrated its utility, since interesting results were obtained on the of population dynamics as the MCRT varies.
3) We study variation in the cell growth rate, whose results constitute new values for characterization of the process.
4) We determine the existence of an inverse proportional relationship between ciliate specific diversity and organic loading rate.
5) It was observed that availability of zinc could vary during the treatment. Its toxicity induced encystement of "Opercularia minima". In sewage water lead salts were rapidly precipitated, and when the maximum concentration tested reached 500 mg/l no toxic effects were observed.
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Arias, Bulbena Anna. "Diel feeding rhythms in marine protistan grazers." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/672410.
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Protistan grazers are a key component of marine planktonic food webs. These marine protists are the major grazers of pelagic primary production in the oceans and, therefore, they display a crucial role in marine biogeochemical cycles as pivotal intermediaries of the energy and mass flux from primary producers to higher trophic levels. Notwithstanding their relevant role in the global pelagic system, some key aspects related to their trophic behaviour remain still poorly understood. Among these features, diel feeding rhythms are of relevant importance as they represent the coupling between the cycles of primary production and the feeding cycles of their predators and, consequently, they strongly condition the carbon flux mediated by marine protistan grazers and the dynamics of planktonic food webs.
This Ph.D. Thesis aims to deepen our knowledge of the diel feeding rhythms in marine protistan grazers, exploring their occurrence and the mechanisms that generate and modulate this rhythmic behaviour. Accordingly, we first investigated the existence of diel feeding rhythms in diverse species of heterotrophic and mixotrophic protistan grazers (the dinoflagellates Gyrodinium dominans, Oxyrrhis marina and Karlodinium armiger, and the ciliates Strombidium arenicola and Mesodinium rubrum). Then, we evaluated how intrinsic characteristics of the prey (Rhodomonas salina), including the growth phase and the diel variations on its stoichiometric composition, as well as own characteristics of the grazers, such as their previous feeding history and the timing for cell division, may be causal factors or perhaps regulate the diel feeding activity of marine protists. We also assessed the effect of extrinsic factors, such as the prey concentration, the light and the risk of predation, on the feeding rhythm of marine protists. Finally, we conducted field experimentation to study the diel feeding rhythms of protistan grazers in a natural ecosystem, the Gullmar Fjord (Sweden).
As major conclusions of the present Ph.D. Thesis, we found that there might not exist a unique underlying mechanism causing the different patterns of diel feeding rhythms we observed in marine protistan grazers. Instead, it appears that marine protists species might have developed feeding rhythms largely conditioned by their physiological and behavioural characteristics, as well as by the ecological conditions from their original habitat, which might determine the factors by which it is modulated.Los ramoneadores protistas son un componente clave de las redes tróficas planctónicas marinas. Estos protistas marinos son los principales consumidores de producción primaria pelágica en los océanos y presentan, por lo tanto, un papel crucial en los ciclos biogeoquímicos marinos como intermediarios fundamentales de los flujos de energía y masa desde los productores primarios hacia niveles tróficos superiores. A pesar de su relevante papel en el sistema pelágico global, algunos aspectos clave relacionados con su comportamiento trófico son todavía poco conocidos. Entre estas características, los ritmos diarios de alimentación son de gran importancia, ya que representan el acoplamiento entre los ciclos de producción primaria y los ciclos de alimentación de sus depredadores y, en consecuencia, condicionan en gran medida el flujo de carbono mediado por los ramoneadores protistas marinos y la dinámica de las redes alimentarias planctónicas. Esta Tesis Doctoral tiene como objetivo profundizar en nuestro conocimiento de los ritmos de alimentación en los ramoneadores protistas marinos, estudiando su ocurrencia y los mecanismos que generan y modulan este comportamiento rítmico. Por ello, primeramente investigamos la presencia de ritmos diarios de alimentación en diversas especies de ramoneadores protistas heterotróficos y mixótrofos (los dinoflagelados Gyrodinium dominans, Oxyrrhis marina y Karlodinium armiger, y los ciliados Strombidium arenicola y Mesodinium rubrum). Luego, evaluamos como características intrínsecas de la presa (Rhodomonas salina), como son su fase de crecimiento y las variaciones diarias en su composición estequiométrica, así como también características propias de los ramoneadores, tales como su historia de alimentación previa y el momento de división celular, pueden ser factores causantes o bien reguladores de los ritmos diarios de alimentación en los protistas marinos. También investigamos el efecto de factores extrínsecos, como son la concentración de presas, la luz y el riesgo de depredación, sobre la actividad de alimentación rítmica de los protistas marinos. Finalmente, realizamos un estudio de campo sobre los ritmos de alimentación diarios de los ramoneadores protistas en un ecosistema natural, el Fiordo de Gullmar (Suecia). Como conclusiones principales de la presente Tesis Doctoral, encontramos que quizás no exista un mecanismo causal único que explique los diferentes patrones de ritmos diarios de alimentación en los ramoneadores protistas marinos. Nuestro estudio parece indicar que las especies de protistas marinos desarrollan ritmos diarios de alimentación condicionados, en gran medida, por sus características fisiológicas y de comportamiento, además de por las particularidades ecológicas de su hábitat de origen, las cuales determinarían los factores por los que este patrón de actividad puede ser modulado.
Els pastors protistes són un component clau de les xarxes alimentàries planctòniques marines. Aquests protistes marins constitueix el principal consumidor de la producció primària pelàgica en els oceans i presenta, per tant, un paper crucial en els cicles biogeoquímics marins com intermediaris fonamentals en els fluxos d’energia i de massa des dels productors primaris cap a nivells tròfics superiors. Tot i el seu rol rellevant en el sistema pelàgic global, alguns aspectes clau relacionats amb el seu comportament tròfic són encara poc coneguts. Entre aquestes característiques, els ritmes diaris d’alimentació són de gran importància, ja que representen l’acoblament entre els cicles de producció primària i els cicles d’alimentació dels seus depredadors i, en conseqüència, condicionen en gran manera el flux de carboni mediat pels pastors protistes marins i la dinàmica de la xarxa alimentaria planctònica. Aquesta Tesi Doctoral té com a objectiu aprofundir en el nostre coneixement sobre els ritmes d’alimentació diaris en els pastors protistes marins, estudiant la seva presencia i els mecanismes que generen i modulen aquest comportament rítmic. Així doncs, primerament vam investigar l’existència de ritmes diaris d’alimentació en diverses espècies de pastors protistes heterotròfics i mixòtrofs (els dinoflagel·lats Gyrodinium dominans, Oxyrrhis marina, i Karlodinium armiger, i els ciliats Strombidium arenicola i Mesodinium rubrum). Llavors, vam avaluar com característiques intrínseques de la presa (Rhodomonas salina), com són la fase de creixement i les variacions diàries en la seva composició estequiomètrica, així com també característiques pròpies dels pastors, com la seva història d’alimentació prèvia i el moment de divisió cel·lular, poden ser factors causants o bé reguladors dels ritmes diaris d’alimentació dels protistes marins. També vam avaluar l’efecte de factors extrínsecs, com són la concentració de presa, la llum i el risc de depredació, en l’activitat d’alimentació rítmica dels protistes marins. Finalment, vam portar a terme un estudi de camp per explorar els ritmes d’alimentació dels pastors protistes en un ecosistema natural (el Fiord de Gullmar, Suècia). Com a conclusions principals de la present Tesi Doctoral, vam trobar que potser no existeix un mecanisme causant únic dels ritmes diaris d’alimentació en pastors protistes marins. El nostre estudi sembla indicar que les espècies de protistes marins desenvolupen ritmes d’alimentació condicionats, en gran manera, per les seves característiques fisiològiques i de comportament, així com també de les particularitats ecològiques del seu hàbitat d’origen, les quals determinarien els factors pels quals el ritme és modulat.
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Rovira, Amigo Sandra. "Estudio de la función de los cilios mediante imagen digital de alta velocidad. comparación con la ultraestructura ciliar en la discinesia ciliar primaria." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/671307.
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Introducció
La discinèsia ciliar primària (DCP) és una malaltia minoritària (1:15.000 nounats) caracteritzada per una alteració a l'estructura i funció ciliar que impedeix el correcte aclariment de les secrecions respiratòries. Les seves manifestacions clíniques inclouen tos productiva, rinitis crònica, otitis de repetició, bronquitis recurrents, bronquièctasis, infertilitat masculina, subfertilitat femenina i situs inversus (50%) o heterotaxia (6-12%). El diagnòstic es basava inicialment en la detecció de les alteracions estructurals mitjançant la microscòpia electrònica. S'han desenvolupat nous mètodes diagnòstics que contribueixen a facilitar el seu diagnòstic, tot i que aquest segueix sent difícil de realitzar.
Objectius
Valorar la utilitat diagnòstica de l'estudi de motilitat ciliar comparat amb l'estudi de la ultraestructura ciliar amb microscòpia electrònica. Establir valors de normalitat de l'estudi de motilitat ciliar. Descriure les característiques d'un grup de pacients afectes de discinèsia ciliar primària. Valorar la utilitat de les proves de despistatge d'aquesta malaltia: qüestionari de símptomes PICADAR i òxid nítric nasal en aquest grup de pacients i en una mostra ampliada.
Mètodes
Selecció d'una mostra de població normal per establir valors de referència de l'estudi de motilitat ciliar.
Realització de l'estudi de motilitat ciliar en una mostra de pacients amb sospita de discinèsia ciliar estudiats prèviament mitjançant microscòpia electrònica i comparació de les dues tècniques.
Valorar la utilitat com a proves de cribratge del qüestionari de símptomes PICADAR i de l'òxid nítric nasal en aquesta mostra de pacients i en una mostra ampliada
Resultats
Els valors de normalitat de l'estudi de motilitat ciliar van ser: freqüència de batec 9,94 Hz (8,56-11,32), índex de discinèsia 12,10% (2,54-21,66) i índex d'immobilitat 0,13% (0-1,51).
Les característiques clíniques més importants que van definir al grup de pacients amb discinèsia ciliar primària van ser: patir distrès respiratori neonatal i presentar tos i rinorrea des del primer dia de vida. La majoria dels pacients amb situs inversus estaven en aquest grup. També presentaven més freqüència de tos contínua productiva, rinorrea persistent, major percentatge de sordesa i de sensació d'oïdes tapades que la resta dels grups.
En el grup de pacients estudiats amb microscòpia electrònica la seva sensibilitat i especificitat va ser del 90,9%, i 48,3% i la de l'estudi de motilitat ciliar del 100% i 80%. En aquest grup, la sensibilitat i especificitat del qüestionari PICADAR va ser del 90,9%, i 86,7% (amb un punt de tall > 4 punts), i la de l'òxid nítric nasal del 80% i 100% (amb un punt de tall 220 ppb o 72,5 nL/min).
A la mostra ampliada de pacients, la sensibilitat i especificitat de l'estudi de motilitat ciliar va ser del 100% i 82,8%, la del qüestionari PICADAR del 92,9% i el 71,7% (amb un punt de tall > 3 punts) i la de la mesura de l'òxid nítric nasal del 91,9% i el 97,5% (amb un punt de tall 248 ppb o 87,9 nL/min).
Conclusions
L'estudi de la motilitat ciliar (freqüència i patró de batec) mitjançant videomicroscòpia òptica va tenir una millor sensibilitat i sobretot una millor especificitat que l'estudi de la ultraestructura amb microscòpia electrònica per al diagnòstic de discinèsia ciliar primària. L'escala predictiva PICADAR i la determinació d'òxid nítric nasal són bones proves de cribratge de la discinèsia ciliar primària, la qual cosa s'ha confirmat tant en la mostra inicial com en la mostra ampliada de pacients.Introducción La discinesia ciliar primaria (DCP) es una enfermedad rara (1:15.000 recién nacidos) caracterizada por una alteración en la estructura y función ciliar que impide el correcto aclaramiento de las secreciones respiratorias. Sus manifestaciones clínicas incluyen tos productiva, rinitis crónica, otitis de repetición, bronquitis recurrentes, bronquiectasias, infertilidad masculina, subfertilidad femenina y situs inversus (50%) o heterotaxia (6-12%). El diagnóstico se basaba inicialmente en la detección de las alteraciones estructurales mediante la microscopía electrónica. Se han desarrollado nuevos métodos diagnósticos que contribuyen a facilitar su diagnóstico, aunque éste sigue siendo difícil de realizar. Objetivos Valorar la utilidad diagnóstica del estudio de motilidad ciliar comparado con el estudio de la ultraestructura ciliar con microscopía electrónica. Establecer valores de normalidad del estudio de motilidad ciliar. Describir las características de un grupo de pacientes afectos de discinesia ciliar primaria. Valorar la utilidad de las pruebas de despistaje de esta enfermedad: cuestionario de síntomas PICADAR y óxido nítrico nasal en este grupo de pacientes y en una muestra ampliada. Métodos Selección de una muestra de población normal para establecer valores de referencia del estudio de motilidad ciliar. Realización del estudio de motilidad ciliar en una muestra de pacientes con sospecha de discinesia ciliar estudiados previamente mediante microscopía electrónica y comparación de ambas técnicas. Valorar la utilidad como pruebas de despistaje del cuestionario de síntomas PICADAR y del óxido nítrico nasal en esta muestra de pacientes y en una muestra ampliada. Resultados Los valores de normalidad del estudio de motilidad ciliar fueron: frecuencia del batido 9,94 Hz (8,56-11,32), índice de discinesia 12,10% (2,54-21,66) e índice de inmovilidad 0,13% (0-1,51). Las características clínicas más importantes que definieron al grupo de pacientes con discinesia ciliar primaria fueron: padecer distrés respiratorio neonatal y presentar tos y rinorrea desde el primer día de vida. La mayoría de los pacientes con situs inversus estaban en este grupo. También presentaban más frecuencia de tos continua productiva, rinorrea persistente, mayor porcentaje de sordera y de sensación de oídos tapados que el resto de los grupos. En el grupo de pacientes estudiados con microscopía electrónica su sensibilidad y especificidad fue del 90,9% y 48,3% y la del estudio de motilidad ciliar del 100% y 80%. En este grupo, la sensibilidad y especificidad del cuestionario PICADAR fue del 90,9% y 86,7% (con un punto de corte > 4 puntos), y la del óxido nítrico nasal del 80% y 100% (con un punto de corte en 220 ppb o 72,5 nL/min). En la muestra ampliada de pacientes, la sensibilidad y especificidad del estudio de motilidad ciliar fue del 100% y 82,8%, la del cuestionario PICADAR del 92,9% y 71,7% (con un punto de corte > 3 puntos) y la de la medida del óxido nítrico nasal del 91,9% y 97,5% (con un punto de corte en 248 ppb o 87,9 nL/min). Conclusiones El estudio de la motilidad ciliar (frecuencia y patrón de batido) mediante videomicroscopía óptica tuvo una mejor sensibilidad y sobretodo una mejor especificidad que el estudio de la ultraestructura con microscopía electrónica para el diagnóstico de discinesia ciliar primaria. La escala predictiva PICADAR y la determinación de óxido nítrico nasal son buenas pruebas de despistaje de la discinesia ciliar primaria, lo que se ha confirmado tanto en la muestra inicial como en la muestra ampliada de pacientes.
Introduction Primary ciliary dyskinesia (PCD) is a rare disease (1:15,000 newborns) characterized by an alteration in the ciliary structure and function that prevents the correct clearance of respiratory secretions. Its clinical manifestations include productive cough, chronic rhinitis, recurrent otitis, recurrent bronchitis, bronchiectasis, male infertility, female subfertility, and situs inversus (50%) or heterotaxia (6-12%). Some years ago, the diagnosis was based on the structural alterations detected by electron microscopy. New diagnostic methods have been developed to contribute its diagnosis, although it remains difficult to perform. Objectives To assess the diagnostic utility of the ciliary motility study compared with the study of the ciliary ultrastructure by electron microscopy. Establish normality values of the ciliary motility study. Describe the characteristics of a group of patients with primary ciliary dyskinesia. To assess the usefulness of screening tests for this disease: the PICADAR symptom questionnaire and nasal nitric oxide in this group of patients and in an extended sample. Methods Selection of a healthy population sample to establish reference values for the ciliary motility study. Ciliary motility study was performed in a sample of patients with suspected ciliary dyskinesia previously studied by electron microscopy and comparison of both techniques. To assess the usefulness of the PICADAR symptom questionnaire and nasal nitric oxide as screening tests in this sample of patients and in an extended sample. Results The normal values of the ciliary motility study were beat frequency 9.94 Hz (8.56-11.32), dyskinesia index 12.10% (2.54-21.66) and immotility index 0,13% (0-1.51). The most important clinical characteristics that defined the group of patients with primary ciliary dyskinesia were neonatal respiratory distress and presenting cough and rhinorrhea from the first day of life. Most of the patients with situs inversus were in this group. They also had a higher frequency of continuous productive cough, persistent rhinorrhea, a higher percentage of deafness and a sensation of blocked ears than the rest of the groups. In the group of patients studied by electron microscopy, its sensitivity and specificity were 90.9% and 48.3% and for the ciliary motility study was 100% and 80%. In this group, the sensitivity and specificity of the PICADAR questionnaire was 90.9% and 86.7% (with a cut-off point > 4 points), and for the nasal nitric oxide was 80% and 100% (with a point of cut-off at 220 ppb or 72.5 nL/min). For the expanded sample of patients, the sensitivity and specificity of the ciliary motility study was 100% and 82.8%, for the PICADAR questionnaire 92.9% and 71.7% (with a cut-off point > 3 points) and for the nasal nitric oxide measurement 91.9% and 97.5% (with a cut-off point of 248 ppb or 87.9 nL/min). Conclusions The study of ciliary motility (frequency and beat pattern) performed by high-speed videomicroscopy had better sensitivity and a better specificity than the study of the ultrastructure performed by electron microscopy for the diagnosis of primary ciliary dyskinesia. The PICADAR predictive questionnaire and the nasal nitric oxide determination are good screening tests for primary ciliary dyskinesia, which has been confirmed both in the initial sample and in the expanded sample of patients.
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Overgaard, Christian Edmund Yeaman Charles. "Deciliation dramatically alters epithelial function." [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/416.
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Xu, Qiang, and 徐强. "Modeling the deformation of primary cilium." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47250008.
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In this thesis we developed a new mechanics model of the primary cilium and analyzed its bending behavior. The primary cilium that extends from the cell surface can detect the mechanical signals of the surrounding environment. Moreover, through its deflection and bending angle, the primary cilium can communicate with the cell regarding the extracellular. Scientists have shown that dysfunction of primary cilia can lead to many diseases as cilia are believed to play an important role in transmitting signals in cells.
A good model of primary cilium can aid in the understanding of the mechanism of its bending movement. Furthermore, a good model is important for determining how the primary cilium contributes to convert mechanical signals into biochemical ones. Previous models have ignored the basal body and transition fiber that are located at the base of the primary cilium.
However, it is clear that the elastic basal body and transition fibers should have a significant effect on the deformation of the whole structure. Aiming to address this issue, we established a model with a rotational spring representing the confinement induced by the basal body and transition fibers. Specially, we developed two governing equations for two different conditions, namely uniformly distributed load and spatially varying load. In addition, this model is valid for situations where the deflection is large.
To obtain the results the shooting and Newton-Raphson methods are used to solve the governing equations numerically. Then, we compared the numerical results with experimental data to test the validity of the model.
Comparison between our model predictions and experimental data showed that the governing equation for spatially varying load described the bending behavior of the primary cilium very well under various realistic conditions, including cases where the flow field is not uniform both spatially and temporally fluid flow with variable velocity.published_or_final_version
Mechanical Engineering
Master
Master of Philosophy
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COSTA, Alejandro Esteweson Santos Faustino da. "Estrutura da comunidade dos tintinnida (Ciliophora: Choreotrichia) em duas áreas recifais (Tamandaré – PE e Abrolhos – BA) do Nordeste do Brasil." Universidade Federal de Pernambuco, 2014. https://repositorio.ufpe.br/handle/123456789/18919.
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A presente dissertação de mestrado é composta por três capítulos, cada um constituindo um artigo a ser submetido para publicação. O primeiro deles consiste de uma revisão do conhecimento que se tem a respeito dos ciliados tintinídeos de águas nordestinas brasileiras. Para isso se consultou trabalhos publicados ao longo das quatro ultimas décadas, e que possuíam alguma relação com os tintinídeos, mesmo não tendo esses ciliados como principal objeto de estudo. Assim foram levantadas todas as espécies de tintinídeos que já possuem registro de ocorrência publicado para a região Nordeste do Brasil. Além das fontes bibliográficas utilizadas, também foram realizadas análises de amostras coletadas em algumas regiões costeiras dos Estados da Paraíba, Pernambuco e Bahia, aumentando a lista de espécies registradas para a região. A partir da consulta dos trabalhos publicados, um total de 91 espécies de tintinídeos foi registrado em águas nordestinas do Brasil. Com a análise das amostras esse número aumentou para 111 espécies, pertencentes a 32 gêneros e 16 famílias. Neste primeiro capítulo é apresentada uma lista das espécies registradas, identificando as regiões nas quais elas ocorrem e os trabalhos utilizados como fonte bibliográfica. O segundo capítulo consiste de um trabalho desenvolvido a fim de se estudar a estrutura da comunidade dos tintinídeos em três áreas recifais na região de Abrolhos, no Estado da Bahia. Em cada área foram delimitados dois pontos de coleta, um sobre os recifes e outro a 1 km de distancia dos recifes. As coletas foram realizadas a cada 6 horas, ao longo de um período de 24 horas, totalizando 8 amostras por área e 3 dias de amostragens (um para cada área). Os tintinídeos foram coletados através de arrastos subsuperficiais de rede de plâncton (20 m de abertura de malha, 30 cm de diâmetro de boca e 2 m de comprimento). Três hipóteses foram testadas: i) a estrutura da comunidade dos tintinídeos varia entre os períodos diurno/noturno; ii) a estrutura da comunidade dos tintinídeos varia em uma escala espacial curta (diferentes pontos em uma mesma área recifal); e iii) a estrutura varia em uma escala espacial de grande extensão (entre as diferentes áreas recifais amostradas). Um total de 24 espécies foi encontrado, sendo todas de distribuição nerítica, típica de águas quentes e cosmopolitas. Apenas a hipótese relacionada com a variabilidade em uma maior escala espacial não foi rejeitada. Existem diferenças significativas entre essas áreas (ANOVA p = 0,017). A existência de duas comunidades distintas de tintinídeos ficou bem evidenciada através de análises de agrupamentos realizadas com amostras e espécies. Existe uma comunidade típica das áreas mais próximas à costa, composta basicamente por espécies de lorica aglutinante e de distribuição nerítica, e outra típica das áreas mais “oceânicas”, formadas basicamente por espécies de lorica hialina e de distribuição cosmopolita e de águas quentes. O grande fator influenciando a comunidade dos tintinídeos na região de Abrolhos é a distância em relação à costa. No terceiro capítulo se estudou a estrutura da comunidade dos tintinídeos na região de Tamandaré, no Estado de Pernambuco. As coletas foram realizadas em uma estação, a cada maré vazante, ao longo de um período de 26 dias. Dados de temperatura, salinidade, teor de clorofila-a e quantidade de material particulado em suspensão foram coletados. Os tintinídeos foram coletados através de arrastos horizontais subsuperficiais de rede de plâncton (20 m de malha). Com o desenvolvimento do estudo tentou se responder as seguintes perguntas: i) existe variação na comunidade dos tintinídeos em um curto intervalo de tempo (período diurno/noturno) na região de Tamandaré? ii) existe algum tipo de influência do ciclo lunar sobre a comunidade dos tintinídeos nessa região? iii) qual fator hidrológico possui mais influência sobre a comunidade desses ciliados? Um total de 20 espécies de tintinídeos foi identificado, sendo a maioria de distribuição nerítica e do gênero Tintinnopsis. A estrutura da comunidade dos tintinídeos não variou em uma escala de tempo curta. Foram detectadas diferenças significativas entre as amostras das diferentes fases do ciclo lunar (Kruskal-Wallis p = 0,005), com as espécies respondendo de diferentes formas. Tintinnopsis nana, T. schotti e T.nucula apresentaram as variações mais pronunciadas. O material particulado em suspensão foi o parâmetro hidrológico de maior influência sobre a comunidade dos tintinídeos, tendo sido encontrada correlação negativa. Por outro lado, foi encontrada correlação positiva entre o material particulado em suspensão e o teor de clorofila-a presente na água. Contudo, o aumento da clorofila-a está associado a uma resposta de organismos fitoplanctônicos a maior atenuação da luz na água e não a um aumento na produtividade. Dessa forma, existe aumento no teor de clorofila, sem que haja aumento na disponibilidade de alimento para os tintinídeos, podendo chegar a haver diminuição nessa disponibilidade, o que levaria a redução da comunidade desses ciliados.
The following master thesis is composed of three chapters; each one of them is a complete scientific paper which is going to be submitted for publication. The first one consists of a review of the knowledge related to the tintinnid ciliates in Brazilian northeastern waters. We consulted not only papers directly focused on the tintinnid ciliates, but also papers related to the microzooplankton, but that mentioned the tintinnids in the results. These papers were published during the last four decades. We assembled all the tintinnid species that had been registered in these papers, as well as worked with samples collected in some coastal regions in the State of Paraíba and Pernambuco, in addition to samples collected in the region of Abrolhos, in the State of Bahia. Through the published papers, we found a total of 91 registered tintinnid species in the northeastern region of Brazil. With the analysis of the samples, this number was raised to 111 species, belonging to 32 genera and 16 families. In this first chapter we present a list of the registered species, providing also the regions where they were found and the papers used as the bibliographical source. The second paper consists of a work developed in order to study the tintinnid community structure in the Abrolhos region, in the State of Bahia. Three reef areas in the Abrolhos region were sampled. In each area, we delimited two sampling points; one located directly above the coral reefs, and the other nearly 1 km away from the reefs. The samplings were performed in each 6 hours, during 24 hours, totalizing 8 samples per area, and three days of field work (one for each area). The tintinnids were collected through subsurface hauls of a plankton net (20 m mesh-size, 30 cm of mouth diameter, and two meters of length). Three hypotheses related to possible variations in the community structure of these ciliates were tested: i) the tintinnid community structure varies in a short temporal scale (between diurnal and nocturnal periods); ii) the community structure varies in a short spatial scale (between different points within a same area); and iii) the community structure varies in a broad spatial scale (between different sampled areas). A total of 24 species was found. All the species was of neritic, warm-water and cosmopolitan distribution. Only the hypothesis related to the variation in a broader spatial scale was not rejected. There are significant differences between the three studied areas (ANOVA p = 0,017). A continent-ocean gradient was highlighted by the clustering of the samples and species. There is a community typical of the areas closer to the coast, which is composed mainly by neritic species of agglutinated loricae, and other community typical of the “more oceanic” areas, which is composed mainly by warm-water and cosmopolitan species of hyaline loricae. The main factor influencing the tintinnid community in the Abrolhos region is the distance from the coast. In the third chapter we studied the tintinnid community structure in the Tamandaré region, Pernambuco State. The samplings were performed each 12 hours in a fixed point during 26 days. Temperature, salinity, chlorophyll-a content and the quantity of particulate material in suspension were evaluated. The tintinnids were collected through horizontal subsurface plankton net (20 m mesh width) hauls. We tried to answer the following questions in the present study: i) Is there any degree of variation in the tintinnid community in a temporal short scale (diurnal and nocturnal periods) in the region of Tamandaré? ii) Does the lunar cycle influence the tintinnid community in some way in this region? iii) Which is the main hydrologic parameter influencing the tintinnid community structure in the Tamandaré region? A total of 20 tintinnid species was identified. Most of them are of neritic distribution, and belongs to the genus Tintinnopsis. No variation in the tintinnid community under a temporal short scale was detected. We found significant differences in the tintinnid community structure in relation to different stages of the lunar cycle (Kruskal-Wallis p = 0,005). The species present different patterns of variation following the lunar cycle. Tintinnopsis nana, T. schotti and T. nucula displayed the most noticeable variations. We found a negative correlation between the tintinnid and the particulate material in suspension; it was the hydrologic parameter with the strongest effect on the tintinnid community. We also found a positive correlation between the particulate material in suspension and the chlorophyll-a content in the water. The increase in the chlorophyll-a content is associated with a response of the phytoplanktonic organisms to the increased light attenuation, and is not related with an increase in production. There is then an increase in chlorophyll-a content, without any increase in the food availability for the tintinnids; a reduction in the food availability is also possible, what could lead to the biomass reduction of the tintinnid community.
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Teixeira, Priscila da Fonseca. "Fitoplâncton e protozooplâncton em viveiros de cultivo de camarão." reponame:Repositório Institucional da FURG, 2011. http://repositorio.furg.br/handle/1/4271.
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Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-16T03:06:44Z No. of bitstreams: 1 Priscila da Fonseca Teixeira.pdf: 335923 bytes, checksum: 69841da63959745c00a7a0e8b7859194 (MD5)
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Na aqüicultura, o sistema sem trocas de água é eficiente e sustentável, permite manejar o balanço entre carbono e nitrogênio, e o desenvolvimento de microorganismos que contribuem na boa qualidade da água, alimentação e sobrevivência do organismo alvo do cultivo. No presente estudo, a composição e densidade de fitoplâncton e protozooplâncton em conjunto com variáveis físico-químicas foram avaliados em viveiros de cultivo de camarão Litopenaeus vannamei (Boone) em sistema sem troca de água em dois tratamentos, com e sem a adição de melaço como fertilizante de carbono. As amostras de água foram coletadas por um período de 70 dias (janeiro a abril de 2009) e os tratamentos apresentaram diferença significativa para o teor dos nutrientes fosfato, silicato e clorofila <20 μm. A clorofila foi dominada pela fração <20μm (>80%) nos dois tratamentos e alcançou os maiores valores (~400 μg L-1) no final do experimento. No viveiro com melaço houve um maior crescimento de cianobactérias filamentosas (Pseudoanabaena spp. e Spirulina sp.), de diatomáceas especialmente Pleurosigma sp. e de ciliados, além da presença de Oxyrrhis marina Dujardin e de Anabaena sp.. No viveiro sem melaço os flagelados e dinoflagelados, especialmente Protoperidinium sp. e outros da ordem Peridiniales foram mais freqüentes e abundantes. Em ambos os tratamentos foi observada uma alta densidade de cianobactérias cocóides e de dinoflagelados (Gymnodiniales e Gyrodinium sp.). Apesar de não terem sido encontradas diferenças estatísticas entre os tratamentos, ficaram claras tendências distintas de composição e densidade do fitoplâncton e protozooplâncton entre os viveiros, indicando a influência da adição de melaço.
In aquaculture the zero water exchange system is efficient, sustainable, and allows the management to balance the carbon and nitrogen compounds through the development of microorganisms contributing to good water quality, feeding and survival of the target organism. In this study, the composition and density phytoplankton and protozooplâncton together with physical and chemical variables were evaluated in shrimp ponds (Litopenaeus vannamei Boone) without water exchange in two treatments with and without the addition of molasses as carbon fertilizer. Water samples were collected during 70 days (January- April 2009). The treatments differed significantly in dissolved inorganic phosphate, silicate and chlorophyll <20 μm. Chlorophyll, dominated by the fraction <20 μm (> 80%), reached the highest values (~400 μg L-1) at the end of the experiment in both treatments. In the pond with molasses, the filamentous cyanobacteria (Pseudoanabaena spp., Spirulina sp.), the diatom Pleurosigma sp. and ciliates reached highest density and the dinoflagellate Oxyrrhis marina Dujardin and the cyanobacteria Anabaena sp. were present. In the pond without molasses, flagellates, and dinoflagellates Protoperidinium sp. and other Peridiniales were more frequent and abundant. In both treatments coccoid cyanobacteria and dinoflagellates (Gyrodinium sp. and other Gymnodiniales) were abundant. Although the differences were not statistically significant, the composition and abundance of phytoplankton and protozooplankton differed over time in both treatments, indicating the influence of the molasses addition.
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Paschoal, Ilma Aparecida 1956. "Ultraestrutura ciliar a microscopia eletronica de transmissão : comparação da prevalencia de anomalias ciliares entre pacientes portadores da sindrome da discinesia ciliar e individuos normais." [s.n.], 1988. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313770.
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Orientador : Albina Messias AltamaniTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: A sindrome da discinesia ciliar é uma das hipóteses diagnósticas que devem ser consideradas em indivíduos com sintomatologia cronica pulmonar e de vias aéreas superiores...Observação: O resumo, na integra, podera ser visualizado no texto completo da tese digital
Abstract: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Doutor em Medicina
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Norton, Michael M. "Modeling problems in mucus viscoelasticity and mucociliary clearance /." Online version of thesis, 2009. http://hdl.handle.net/1850/10822.
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Wan, Yixin. "Modulation and synchronization of eukaryotic flagella." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708434.
Full textBooks on the topic "Ciliats"
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International, Wendlandian Symposium :. Five Decades of Basic Research on Cilia/Flagella and Ciliates/Flagellates (2012 Lüchow Lower Saxony Germany). Cilia and flagella, ciliates and flagellates: Ultrastructure and cell biology, function and systematics, symbiosis and biodiversity. Stuttgart: Schweizerbart Science Publishers, 2014.
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Witzany, Guenther, and Mariusz Nowacki, eds. Biocommunication of Ciliates. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32211-7.
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Demir, Necla. Gadidae: Ciliata Couch, 1832. Copenhagen: International Council for the Exploration of the Sea, 1986.
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Carey, Philip G. Marine interstitial ciliates: An illustrated key. London: Chapman & Hall, 1992.
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Pattern formation: Ciliate studies and models. New York: Oxford University Press, 1989.
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Lynn, Denis H., ed. The Ciliated Protozoa. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-1-4020-8239-9.
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Satir, Peter, and Søren Tvorup Christensen, eds. Cilia. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3789-9.
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Foissner, Wilhelm. Identification and ecology of limnetic plankton ciliates. Munich: Informationberichte des Bayerischen Landesamtes furInstitut für Wasserwirtschaft, 1999.
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Dolan, John R., David J. S. Montagnes, Sabine Agatha, D. Wayne Coats, and Diane K. Stoecker, eds. The Biology and Ecology of Tintinnid Ciliates. Chichester, UK: John Wiley & Sons, Ltd, 2012. http://dx.doi.org/10.1002/9781118358092.
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Melkonian, Michael, Robert A. Andersen, and Eberhard Schnepf. The Cytoskeleton of Flagellate and Ciliate Protists. Vienna: Springer Vienna, 1991. http://dx.doi.org/10.1007/978-3-7091-6714-4.
Full textBook chapters on the topic "Ciliats"
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Satir, Peter, and Birgit H. Satir. "Intracytoplasmic Signaling from Cilia in Ciliates." In Biocommunication of Ciliates, 51–63. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32211-7_4.
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Jorissen, Mark, and Martine Jaspers. "Cilia, Ciliary Movement, and Mucociliary Transport." In Nasal Physiology and Pathophysiology of Nasal Disorders, 15–25. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37250-6_2.
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Mahmud, Rohela, Yvonne Ai Lian Lim, and Amirah Amir. "Ciliate." In Medical Parasitology, 75–78. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-68795-7_9.
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Gooch, Jan W. "Ciliate." In Encyclopedic Dictionary of Polymers, 882. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_13399.
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Ehrenfeucht, Andrzej, Tero Harju, Ion Petre, David M. Prescott, and Grzegorz Rozenberg. "Ciliates." In Natural Computing Series, 23–35. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-06371-2_2.
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Piekarski, Gerhard. "Ciliates." In Medical Parasitology, 111–15. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-72948-5_5.
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Frankel, Joseph. "Pattern Formation in Ciliary Organelle Systems of Ciliated Protozoa." In Ciba Foundation Symposium 29 - Cell Patterning, 25–49. Chichester, UK: John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470720110.ch3.
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Kreier, J. P., and J. R. Baker. "Symbiotic ciliates." In Parasitic Protozoa, 215–23. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-011-6847-2_10.
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Luporini, P., C. Miceli, C. Ortenzi, and A. Vallesi. "Ciliate Pheromones." In Signaling Mechanisms in Protozoa and Invertebrates, 80–104. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-80106-8_5.
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Pavelka, Margit, and Jürgen Roth. "Ciliary Pathology: Immotile Cilia Syndrome and Kartagener Syndrome." In Functional Ultrastructure, 246–47. Vienna: Springer Vienna, 2010. http://dx.doi.org/10.1007/978-3-211-99390-3_127.
Full textConference papers on the topic "Ciliats"
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Ueno, Hironori, Takuji Ishikawa, Khanh Huy Bui, Kohsuke Gonda, Takashi Ishikawa, and Takami Yamaguchi. "Analysis of Ciliary Motion and the Axonemal Structure in the Mouse Respiratory Cilia." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80232.
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Mucociliary clearance on the surface of the tracheal lumen is an important component of lung defense against dust mites and viruses. However, the axonemal structure that achieves effective ciliary motion and the mechanisms by which discretely distributed ciliary cells generate directional flow are unknown. In this study, we examined individual ciliary motion with 7–9-nm spatial precision by labeling the ciliary tip with quantum dots, and detected an asymmetric beating pattern. Cryo-electron tomography revealed that the densities of two inner dynein arms were missing from at least two doublet microtubules in the axonemal structure. Although the flow directions generated by individual ciliated cells were unsteady and diverse, the time- and space-averaged velocity field was found to be directional. These results indicate that the asymmetric ciliary motion is driven by the asymmetric axonemal structure, and it generates overall directional flow from the lungs to the oropharynx on sparsely distributed ciliated cells.
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Chen, Duanduan, Kyosuke Shinohara, Jun Ren, and Hiroshi Hamada. "The Protein-Driven Ciliary Motility in Embryonic Nodes: A Computational Model of Ciliary Ultrastructure." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62460.
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The movement of embryonic cilia presents a crucial function in specifying left-right axis for vertebrates. Those mono-cilia are primary (9+0) cilia, whose characteristic architecture is based on a cylindrical arrangement of 9 microtubule doublets. Dynein motors located between adjacent doublets convert the chemical energy of ATP hydrolysis into mechanical work that induces doublet sliding. Passive components, such as the mediated cytoplasm, the ciliary membrane, and other possibly-existent structures constraint the ciliary motion and maintain the cilia structural integrity, thus resulting in the axonemal bending. Dynein motors located along microtubule doublets in a motile nodal cilium activate in a sequential manner. However, due to inherent difficulties, the dynein activation patterns in moving cilia can hardly be directly observed. The exact mechanism that controls ciliary motion is still unrevealed. In this work, we present a protein-structure model reconstructed from transmission electron microscopy image set of a wide-type embryonic cilium to study the dynein-dependent ciliary motility. This model includes time accurate three-dimensional solid mechanics analysis of the sliding between adjacent microtubule doublets and their induced ciliary bending. As a conceptual test, the mathematical model provides a platform to investigate various assumptions of dynein activity, which facilitates us to evaluate their rationality and to propose the most possible dynein activation pattern. The proposed protein-trigger pattern can reproduce the rotation-like ciliary motion as observed by experiments. Further application of this approach to mutant cilia with ultrastructural modifications also shows consistency to experimental observations. This computational model based on solid mechanics analysis may improve our understandings regarding the protein-beating problems of cilia, and may guide and inspire further experimental investigations on this topic.
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Salman, Huseyin Enes, Natalie Jurisch Yaksi, and Huseyin Cagatay Yalcin. "Computational Modeling of Motile Cilia Generated Cerebral Flow Dynamics in Zebrafish Embryo." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0128.
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Background: Motile cilia are hair-like microscopic structures, which move the fluids along the epithelial surfaces. Cilia cover a wide range of regions in the nervous system, such as the nasal cavity, spinal cord central canal, and brain ventricles. Motile cilia-driven cerebrospinal fluid (CSF) flow in the brain ventricles has an important role in the brain development. Embryos lacking motile cilia develop neurological defects due to altered CSF flow. Aim: To investigate the effect of motile-cilia motion on the altered CSF flow, and to understand the role of CSF flow in the brain development and physiology. Methods: The dynamics of motile-cilia driven flow is analyzed employing computational fluid dynamics (CFD) modeling. A 2D model is generated using the time-lapse microscopic movies showing movements of a fluorescently labeled motile-cilia in a zebrafish embryo (48-hour post-fertilization). The effects on the generated flow are elucidated by investigating the cilia beating angle, multiple cilia formations, and the phase difference between different ciliary beats. Results: Ciliary beating generated a directional flow in the form of a circulating vortex. The angle of ciliary beating significantly affected the flow velocity. As the angle between the wall and cilia decreases, the flow becomes more efficient by achieving higher velocities. Multiple cilia formations increased the flow velocity but the significance of multiple cilia is not as critical as the beating angle. Interestingly, phase difference between the multiple cilia beats increased the directional flow velocity. Conclusion: Motile-cilia generated flow dynamics are investigated, and it is concluded that out-of-phase multiple ciliary beating is the optimum form of beating in order to generate a directional flow.
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Alexeev, Alexander, Rajat Ghosh, Gavin A. Buxton, O. Berk Usta, and Anna C. Balazs. "Using Actuated Cilia to Regulate Motion of Microscopic Particles." In ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13227.
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Marine animals use microscopic elastic filaments, or cilia, to capture food particles that are suspended in the surrounding solution [1, 2]. In the respiratory tract, active cilial layers facilitate the transport of particulates such as dust or mucous. These motile cilia experience the surrounding fluid as a highly viscous, low Reynolds number environment, where the effects of inertia are negligible [2]. Nevertheless, by oscillating in a periodic, time-irreversible manner, the elastic cilia can generate net currents within the fluid and thereby, effectively transport and direct microscopic particles. The behavior of these biological cilia provides a useful design concept for creating microfluidic devices where actuated “synthetic cilia” would regulate the movement of micrometer-sized particles, such as biological cells and polymeric microcapsules.
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Xu, Gang, Kate S. Wilson, Ruth J. Okamoto, Jin-Yu Shao, Susan K. Dutcher, and Philip V. Bayly. "The Apparent Flexural Rigidity of the Flagellar Axoneme Depends on Resistance to Inter-Doublet Sliding." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80220.
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Cilia are thin subcellular organelles that bend actively to propel fluid. The ciliary cytoskeleton (the axoneme) consists of nine outer microtubule doublets surrounding a central pair of singlet microtubules. Large bending deformations of the axoneme involve relative sliding of the outer doublets, driven by the motor protein dynein. Ciliary structure and function have been studied extensively, but details of the mechanics and coordination of the axoneme remain unclear. In particular, dynein activity must be switched on and off at specific times and locations to produce an oscillatory, propulsive beat. Leading hypotheses assert that mechanical feedback plays a role in the control of dynein activity, but these ideas remain speculative.
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Moran, Emma C., Pedro M. Baptista, Kenichiro Nishii, David Wasnick, Shay Soker, and Jessica L. Sparks. "Expression of Primary Cilia on Liver Stem and Progenitor Cells: Potential Role for Mechanosensing in Liver Development." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14122.
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The primary cilium is a non-motile organelle that projects out from the plasma membrane of many cell types in the body. It consists of an axoneme with microtubules arranged in a 9+0 arrangement that extends from the mother centriole contained within the basal body. Once thought to be a non-essential organelle, it is now known that primary cilia have an important role in embryonic and post-natal development, as well as maintenance of adult tissues. Mutations affecting primary ciliary development result in a class of serious diseases known as ciliopathies [1, 2]. Recent research suggests that the primary cilia/ centrosomes might play a role in embryonic stem cell differentiation through cell cycle regulation and their association with the Hedgehog signaling pathway [3, 4].
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Reula, Ana, Amparo Escribano, Silvia Castillo, Sara Pastor, Silvia Vicente, Armengot Miguel, Francisco Jose Dasi Fernandez, and Irene Garcia. "Oxidative stress in ciliated nasal epithelial cells from patients with primary ciliary dyskinesia." In ERS International Congress 2016 abstracts. European Respiratory Society, 2016. http://dx.doi.org/10.1183/13993003.congress-2016.pa1224.
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Fadaee-Shohada, Mina J., Robert Hirst, Peter W. Andrew, and Christopher O'Callaghan. "The Effect Of Streptococcus Pneumoniae On Ciliated Respiratory Cells In Patients With Primary Ciliary Dyskinesia." In American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a5655.
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Kuznetsov, A. V., D. G. Blinov, A. A. Avramenko, I. V. Shevchuk, A. I. Tyrinov, and I. A. Kuznetsov. "Modeling Leftward Flow in the Embryonic Node." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62503.
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The establishment of the left-right asymmetry during the development of vertebrates is a fascinating phenomenon that is still not fully understood. Extensive research suggests that in mice a small triangular cavity, called the ventral node, is responsible for breaking the left-right symmetry. A mouse node is ∼ 50 microns across and ∼10 microns deep. The surface of the nodal pit is covered by 200–300 monocilia whose rotation is responsible for the leftward flow in the node. We developed a simplified method of modeling the extraembryonic fluid flow and morphogen transport in a nodal cavity. We simplified the problem as flow in a 2D cavity; the effect of rotating cilia was modeled by specifying a constant vorticity at the edge of the ciliated layer. We also developed approximate solutions for morphogen transport in the nodal pit. The solutions were obtained utilizing the proper generalized decomposition method. We compared our approximate solutions with the results of numerical simulation of flow caused by the rotation of 81 cilia, and obtained reasonable agreement in most of the flow domain. We discuss locations where agreement is less accurate. The obtained semi-analytical solutions enable a quick analysis of flow and morphogen distribution in a nodal pit.
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Lucas, Jane S., Elizabeth C. Adam, Patricia Goggin, Claire L. Jackson, N. Powles-Glover, J. Humphreys, M. Fray, M. Cheeseman, Dominic P. Norris, and Peter M. Lackie. "Static Respiratory Cilia With Normal Ultrastructure In Inversus Viscerum (iv) Mouse- A Potential Model Of Primary Ciliary Dyskinesia?" In American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a6724.
Full textReports on the topic "Ciliats"
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Song, Pill-Soon. Photo-Signal Transduction in Motile Ciliate Blepharisma. Fort Belvoir, VA: Defense Technical Information Center, March 1995. http://dx.doi.org/10.21236/ada295889.
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Morris, Kristen. Cilia. Ames: Iowa State University, Digital Repository, February 2013. http://dx.doi.org/10.31274/itaa_proceedings-180814-585.
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Giráldez, Fernando. El oído: de las células ciliadas al éxtasis. Sociedad Española de Bioquímica y Biología Molecular (SEBBM), August 2016. http://dx.doi.org/10.18567/sebbmdiv_anc.2016.08.1.
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Serra, Rosa, and Andra Frost. Primary Cilia in Breast Cancer Progression. Fort Belvoir, VA: Defense Technical Information Center, June 2010. http://dx.doi.org/10.21236/ada601708.
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Anholt, Robert H., R. W. Farmer, and Christa A. Karavanich. Excitation by Odorants of Olfactory Receptor Cells: Molecular Interaction at the Ciliary Membrane. Fort Belvoir, VA: Defense Technical Information Center, January 1989. http://dx.doi.org/10.21236/ada214088.
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Mochan, Daria. Evaluation of a Rapid-screening Toxicity Test Using the Ciliate, Colpoda inflata (Stokes): Sensitivity and Bioavailability to Model Compounds. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.7041.
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