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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Datorträning i läsflyt och stavning : analys och utvärdering av fixerad och resultatstyrd flash-cardexponering

Johansson, Maj-Gun January 2010 (has links)
During the last decade new attention has been paid to reading fluency. One reason might be that training studies often have failed to provide growth in reading rate in spite of the fact that the accuracy problem was remediated. Recent research has also indicated that, in languages with a consistent mapping between graphemes and phonemes, automatization of decoding processes are more difficult to reach than aquiring accurate decoding skills. Several studies have found that computer-based flashcard training seems to be a productive way to develop reading fluency. The aims of this thesis are partly to replicate some of the previous studies with time pressured exposure and partly to examine whether the condition with time pressure is more effective than the flashcard condition with fixed exposure duration. In the time pressure condition, the exposure duration was varied as a function of accuracy. This thesis reports one main study and two case studies. The participants in the main study were 17 males and 11 females between the ages of 11 and 17. All of them were poor readers, scoring below the 11th percentile on standardized reading test for their age group. The two participants of the first case study were the poorest readers of all. Their decoding strategies differed greatly. The younger of them, a slow reader in the fourth grade, can be seen as “a speller” with most impairment in the orthographic processing and the older, a quick reader in the fifth grade, can be seen as “a guesser” with most impairment in the phonological processing. The four participants in the second case study were moderately poor readers between the ages of 12 and 14. Each participant practiced the two different conditions of the computer-based flashcard training with spelling response in sessions about twenty minutes long twice to three times a week during three to four months. Teacher-controlled tuition was only given in some pre-sessions. According to the online results, all participants in both of the exposure conditions were capable of keeping the accuracy at a high level, i.e. fluent reading was expected to be developed. A battery of silent and oral reading tests and spelling-to-dictation tests was used in pre-, middle- and posttest. Both accuracy and rate were measured in reading. Except for “the speller” in the first case study, significant improvements were found on all tests for both conditions. The best progress was during the first training period independent of condition. Positive effects were found for both trained and untrained material and for words and pseudo-words. The reading progress has in general been better than the average student usually develops during the same time. The students reported the time pressured condition as being more effective and motivating but no significant difference was found between the two conditions in the pre- to posttests.
2

Studies of urban air quality using electrochemical based sensor instruments

Popoola, Olalekan Abdul Muiz January 2012 (has links)
Poor air quality has been projected to be the world’s top cause of environmental premature mortality by 2050 surpassing poor sanitation and dirty water (IGBP / IGAC press release, 2012 ). One of the major challenges of air quality management is how to adequately quantify both the spatial and temporal variations of pollutants for the purpose of implementing necessary mitigation measures. The work described in this thesis aims to address this problem using novel electrochemical based air quality (AQ) sensors. These instruments are shown to provide cost effective, portable, reliable, indicative measurements for urban air quality assessment as well as for personal exposure studies. Three principal pollutants CO, NO and NO2 are simultaneously measured in each unit of the AQ instrument including temperature / RH measurements as well as GPS (for time and position) and GPRS for data transmission. Laboratory studies showed that the electrochemical sensor nodes can be highly sensitive, showing linear response during calibration tests at ppb level (0-160 ppb). The instrumental detection limits were found to be < 4 ppb (CO and NO) and < 1 ppb for NO2 with fast response time equivalent to t90 < 20 s. Several field studies were carried out involving deployment of both the mobile and static electrochemical sensor nodes. Results from some short-term studies in four different cities including Cambridge (UK), London (UK), Valencia (Spain) and Lagos (Nigeria) are presented. The measurements in these cities represent snapshot of the pollution levels, the stark contrast between the pollution level especially CO (mean mixing ratio of 16 ppm over 3 hrs) in Lagos and the other three cities is a reflection of the poor air quality in that part of the world. Results from long-term AQ monitoring using network of 46 static AQ sensors were used to characterise pollution in different environments ranging from urban to semi-urban and rural locations. By coupling meteorological information (wind measurements) with pollution data, pollution sources, and phenomena like the street canyon effect can be studied. Results from the long-term study also revealed that siting of the current fixed monitoring stations can fail to represent the actual air quality distribution and may therefore be unrepresentative. This work has shown the capability of electrochemical based AQ sensors in complementing the existing fixed site monitors thus demonstrating an emerging measurement paradigm for air quality monitoring and regulation, source attribution and human exposure studies.
3

Vliv doby působení druhého jazyka na chápání vztažných vět u dětí školního věku / Effect of time of exposure to L2 on the comprehension of relative clauses in primary school children

Brabcová, Alžběta January 2018 (has links)
This study investigates the impact of second language age of onset on the development of syntactic competence in bilinguals. Forty-five bilingual children were tested using a picture- matching task with relative clauses. In this paradigm, children are aurally presented with relative clauses of various kinds and are asked to match what they hear with the appropriate picture (out of four choices) on the screen. More specifically, our experiment compared the comprehension of subject- vs. object-extracted center-embedded relative clauses and contained sentences with noun phrases (NPs) that did or did not match in number (both NPs singular or plural = match, one NP singular, one NP plural = mismatch). We compared the performance of a group of Simultaneous bilinguals (two languages since birth), Early sequential bilinguals (first exposure to L2 - English between the ages of 1 to 4) and Late sequential bilinguals (first exposure to L2 -English after the age of 4 but latest at the age of 6 - primary school). The mean age of the participants at the time of testing was approx. 10 years of age. The results show that there is a varied pattern in the comprehension strategies used among the three bilingual groups. The group of Simultaneous bilinguals showed more reliance on the syntactic information contained in...
4

Control of enteric parasitic diseases of farmed gilthead sea bream: New insights into Enteromyxum leei (Myxozoa) and Enterospora nucleophila (Microsporidia) infections

Picard Sánchez, María Amparo 30 May 2021 (has links)
Tesis por compendio / [ES] La producción en acuicultura se ha visto menguada por aparición de enfermedades en los sistemas de cría de peces. En concreto, en la dorada (Sparus aurata), hay dos parásitos destacados: Enteromyxum leei (Myxozoa) y Enterospora nucleophila (Microsporidia). Hasta la fecha, para ninguno de los dos se ha establecido un cultivo in vitro, y solo para E. leei se ha conseguido establecer un modelo de mantenimiento de la infección in vivo. La presente tesis pretende incrementar el conocimiento sobre estos parásitos y sus relaciones con el hospedador, sentando las bases para generar soluciones que puedan ser aplicadas en la acuicultura. El objetivo con E. leei fue estudiar la inmunidad adquirida inducida en la dorada y la posibilidad de generar herramientas de diagnóstico y vacunas frente a esta enfermedad. Para ello, primero se demostró la resistencia del pez al parásito tras una segunda exposición, la cual duró hasta 16 meses. Además, la resistencia parece estar correlacionada con altos niveles de inmunoglobulina (Ig) M específica en sangre, y una alta expresión de Igs, incluso antes de la re-exposición al parásito. El siguiente paso fue afinar el protocolo de infección con E. leei. Los resultados mostraron que una semana es suficiente para transmitir la infección de E. leei por efluente, independientemente de la temperatura. Tras la demostración de la respuesta adaptativa eficaz frente a E. leei, y al disponer de un modelo de infección refinado, se realizó un ensayo de inmunización pasiva. Aquí, los resultados mostraron que los anticuerpos especi'ficos efectivamente consigue ralentizar la invasión del intestino por el parásito y disminuir los síntomas de la enfermedad. Paralelamente, el resultado del análisis del repertorio de las regiones variables de la IgM e IgT del intestino peces resistentes mostró la inducción de una respuesta policlonal en las ce'lulas B. En base a estos resultados, se realizó una búsqueda de antígenos de E. leei que pudieran ser utilizados como candidatos para la producción de vacunas (análisis proteómico) o herramientas de diagnóstico (análisis in silico). Para ello, se ensambló un transcriptoma de novo utilizando una muestra mixta de intestino de dorada y parásito. Los resultados dieron lugar a 7 y 12 candidatos en la búsqueda in silico y proteómica, respectivamente. En los estudios de E. nucleophila, debido a que fue descrita muy recientemente, el punto de partida fue más básico. Las muestras de este parásito solo se pueden obtener de brotes naturales en piscifactorias. Por ello, primero se realizó un estudio de caracterización de la patología de la infección a partir de peces infectados naturalmente. En etapas tempranas de la infección, el parásito se localiza principalmente en el intestino, pero meses después, la prevalencia en intestino baja e incrementa en los órganos hematopoyéticos y el esto'mago. Los signos clínicos de la infección consistieron en una reducción significativa del crecimiento, emaciación, y palidez de las paredes intestinales. A nivel celular, en los casos ma's graves se observó hipercelularidad en el epitelio intestinal y proliferación de ce'lulas rodlet, un elevado número de linfocitos en la base del epitelio e infiltración de granulocitos acidófilos en el epitelio intestinal. Finalmente se probaron varias formas de transmisión horizontal de E. nucleophila (cohabitación, efluente, intubación oral y anal) con para desarrollar un modelo de mantenimiento in vivo. Se consiguió la transmisión el parásito por todas las vías, pero con una disminución de prevalencia a lo largo del tiempo. Variables como la temperatura, la dosis, y el estado de los peces donantes parecen ser más determinantes que la ruta seleccionada para la transmisión. Entre las rutas probadas, la intubación anal parece ser la más prometedora, pero ninguna de ellas fue capaz de reproducir los signos clínicos observados en las infecciones naturales. / [CA] La producció en aqüicultura s'ha vist minvada per aparició de malalties en els sistemes de cria de peixos. En concret, en l'orada (Sparus aurata), hi ha dos paràsits destacats: Enteromyxum leei (Myxozoa) i Enterospora nucleophila (Microsporidia). Fins avui, per a cap dels dos s'ha establert un cultiu in vitro, i només per a E. leei s'ha aconseguit establir un model de manteniment de la infecció in vivo. La present tesi pretén incrementar el coneixement sobre aquests paràsits i les seves relacions amb l'hoste, establint les bases per a generar solucions que puguin ser aplicades en l'aqüicultura. L'objectiu amb E. leei va ser estudiar la immunitat adquirida induïda en l'orada i la possibilitat de generar eines de diagnòstic i vacunes enfront d'aquesta malaltia. Per a això, primer es va demostrar la resistència del peix al paràsit després d'una segona exposició, la qual va durar fins a 16 mesos. A més, la resistència sembla estar correlacionada amb alts nivells d'immunoglobulina (Ig) M específica en sang, i una alta expressió de Igs, fins i tot abans de la re-exposició al paràsit. El següent pas va ser afinar el protocol d'infecció amb E. leei. Els resultats van mostrar que una setmana és suficient per a transmetre la infecció de E. leei per efluent, independentment de la temperatura. Després de la demostració de la resposta adaptativa eficaç enfront de E. leei, i en disposar d'un model d'infecció refinat, es va realitzar un assaig d'immunització passiva. Aquí, els resultats van mostrar que els anticossos específics efectivament aconsegueix alentir la invasió de l'intestí pel paràsit i disminuir els símptomes de la malaltia. Paral·lelament, el resultat de l'anàlisi del repertori de les regions variables de la IgM i IgT de l'intestí peixos resistents va mostrar la inducció d'una resposta policlonal en les cèl·lules B. Sobre la base d'aquests resultats, es va realitzar una cerca d'antígens de E. leei que poguessin ser utilitzats com a candidats per a la producció de vacunes (anàlisis proteómico) o eines de diagnòstic (anàlisi in silico). Per a això, es va assemblar un transcriptoma de novo utilitzant una mostra mixta d'intestí d'orada i paràsit. Els resultats van donar lloc a 7 i 12 candidats en la cerca in silico i proteòmica, respectivament. En els estudis de E. nucleophila, pel fet que va ser descrita molt recentment, el punt de partida va ser més bàsic. Les mostres d'aquest paràsit només es poden obtenir de brots naturals en piscifactorias. Per això, primer es va realitzar un estudi de caracterització de la patologia de la infecció a partir de peixos infectats naturalment. En etapes primerenques de la infecció, el paràsit es localitza principalment en l'intestí, però mesos després, la prevalença en intestí baixa i incrementa en els òrgans hematopoètics i l'estómac. Els signes clínics de la infecció van consistir en una reducció significativa del creixement, emaciació, i pal·lidesa de les parets intestinals. A nivell cel·lular, en els casos més greus es va observar hipercelularidad en l'epiteli intestinal i proliferació de cèl·lules rodlet, un elevat nombre de limfòcits en la base de l'epiteli i infiltració de granulòcits acidòfils en l'epiteli intestinal. Finalment es van provar diverses formes de transmissió horitzontal de E. nucleophila (cohabitació, efluent, intubació oral i anal) amb per a desenvolupar un model de manteniment in vivo. Es va aconseguir la transmissió el paràsit per totes les vies, però amb una disminució de prevalença al llarg del temps. Variables com la temperatura, la dosi, i l'estat dels peixos donants semblen ser més determinants que la ruta seleccionada per a la transmissió. Entre les rutes provades, la intubació anal sembla ser la més prometedora, però cap d'elles va ser capaç de reproduir els signes clínics observats en les infeccions naturals. / [EN] Aquaculture production is hampered by the emergence of parasite diseases in fish farming systems. Among them, in Sparus aurata, there are two important enteric parasites described: Enteromyxum leei (Myxozoa) Enterospora nucleophila (Microsporidia). To date, no in vitro culture has been established for either parasite, and only for E. leei was it possible to establish a model for maintaining the infection in vivo. The aim of this thesis is to gain new knowledge about these parasites and their relationship with the host, also the basic foundations for generating solutions that can be applied in aquaculture. The general objective for E. leei was to study the acquired immunity induced in gilthead bream and the possibility of generating diagnostic tools and vaccines against this disease. To this end, resistance against the parasite was assessed with a second exposure against the parasite, which showed a resistance for at least 16 months. Besides resistance seemed to be correlated with high levels of specific immunoglobulin (Ig) M in blood, and a high expression of Igs, in particular, the soluble forms, even before re-exposure to the parasite. The next step was refining the protocol for effluent infection with E. leei by studying infection at different exposure time points, temperatures and population densities. The results showed that one week of exposure is sufficient to spread E. leei infection by effluent, regardless of temperature. After demonstrating the resistance against E. leei, and with a refined infection model, a passive immunization assay was performed. The results showed that the serum with specific antibodies effectively slows down the invasion of the gut by the parasite and reduces the symptoms of the disease. At the same time, the analysis of the repertoire of the variable regions of intestinal IgM and IgT showed an induction of a polyclonal response in B cells. On the basis of these results, a research was carried out for E. leei antigens that could have use as candidates for the production of vaccines (proteomic study) or diagnostic tools (in silico study) using the parasite transcriptomic data. To do this, a de novo transcriptome was assembled using a mixed sample of gilthead sea bream and parasite, with a posterior filtrate of the sequences. The In silico and proteomic analysis search resulted in 7 and 12 transcripts, respectively, which are being used for diagnostic and vaccine production. The starting point was more basic in E. nucleophila studies, since this is a recently described disease. The samples of this parasite can only be obtained from natural outbreaks in fish farms. Therefore, first study was carried out to characterize the pathology of the infection of naturally infected fish. In the early stages of the infection, the parasite is mainly located in the intestine, but months later, the prevalence is lower in the intestine and increases in the hematopoietic organs and the stomach. Clinical signs of infection were significant reduction in growth, wasting, and intestinal walls paleness. At the cellular level, in the most severe cases hypercellularity in the intestinal epithelium, proliferation of rodlet cells, high number of lymphocytes at the base of the epithelium and infiltration of acidophilic granulocytes in the intestinal epithelium were observed. Finally, horizontal transmission of E. nucleophila was tried using different transmission methods: cohabitation, effluent, and oral and anal intubation. Transmission of the parasite was achieved with all routes, but there was a decrease in prevalence over time in all cases except for the anal route. Variables such as temperature, dose, and the status of the donor fish appear to be more important than the selected route. Among the routes tested, anal intubation seemed to be the most promising, as it was sustained over a longer period of time, but none of them was able to reproduce the same clinical signs of infection observed in natural infections. / The authors kindly acknowledge the collaboration of anonymous fish farming companies allowing access to the animals during the disease outbreaks. We thank J. Monfort and L. Rodríguez (IATS-CSIC) for the technical assistance on histological processing.This work has been carried out with financial support from the European Union and the Spanish Ministry of Economy and Competitiveness (MINECO) under grant projects ParaFishControl (H2020-634429) and AGL2013-R-48560-C2-2-R, respectively. APS was contracted under ParaFishControl project. Primer sequences and access to the gilthead sea bream transcriptomic database were kindly provided by Prof. J. Pérez-Sánchez of the IATS- Nutrigenomics group. The authors thank I. Vicente for fish maintenance and technical assistance during samplings. The authors thank P. Boudinot (INRAE) for his help in designing and interpreting the immunoglobulin repertoire study and results, J. Pérez-Sánchez (IATS-CSIC) for providing access to the gilthead sea bream genome sequences to perform the repertoire analysis.This work was funded by the European Research Council (ERC Consolidator Grant 2016 725061 TEMUBLYM). / Picard Sánchez, MA. (2021). Control of enteric parasitic diseases of farmed gilthead sea bream: New insights into Enteromyxum leei (Myxozoa) and Enterospora nucleophila (Microsporidia) infections [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/167035 / TESIS / Compendio

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