Os artrópodes constituem o grupo mais diverso do Reino Animal, apresentando uma distribuição muito ampla nos ecossistemas e habitats. O fato de esses animais terem mudado muito pouco durante sua evolução e estarem bem adaptados aos ambientes inóspitos e com uma alta presença de microorganismos patogênicos, torna interessante a realização de estudos sobre o seu sistema imunológico. Parte importante deste sistema são os peptídeos antimicrobianos, que controlam a invasão dos diferentes patógenos. Estas moléculas não só podem fornecer informação sobre o sistema imune e o funcionamento deste, como também pode ajudar a buscar alternativas nas lutas contra as doenças infecciosas. Sendo assim, se torna interessante a purificação e a caracterização dos peptídeos antimicrobianos presentes nesses animais como também o conhecimento do funcionamento de seu sistema imune. Neste trabalho foram utilizadas duas espécies da ordem quilópoda: Scolopendra viridicornis e Otostigmus cavalcanti como modelo experimental. Foi avaliada a presença de moléculas bioativas na hemolinfa (plasma e hemócitos) e no extrato total do corpo, bem como a produção destas moléculas após o animal receber um estímulo ou injúria. Foi observada a presença de diferentes frações com atividade antimicrobiana na hemolinfa (plasma e hemócitos) e no extrato total de animais desafiados e não desafiados em Otostigmus cavalcanti, apresentando um aumento na atividade antimicrobiana nos animais do grupo estimulado. O que pode significar que algumas das moléculas antimicrobianas estão presentes constitutivamente no animal enquanto outras precisam de um estímulo para ser expressas. No plasma de S. viridicornis foram observadas diferentes frações com atividade antimicrobiana, observando-se atividade contra a bactéria Gram-negativa E coli e contra a levedura C. albicans. No entanto, nos hemocitos, diferentes frações apresentaram atividade somente contra a bactéria Gram-positiva M. luteus. Na porção hidrofóbica do extrato total do corpo de S. viridicornis também foram observadas diferentes frações com atividade antimicrobiana. No material eluído em 5% de ACN, por análise de ESI-MS de uma fração com atividade contra M. luteus foram observadas duas moléculas com massa molecular baixa (848,49 e 861,94 Da). Ainda no extrato total da fração hidrofóbica foram observadas duas moléculas que se apresentaram puras. A primeira destas mostrou uma massa molecular de 1,7 kDa mas ainda não foi caracterizada. Enquanto a segunda evidenciou um peptídeo de 925,4658 Da e cuja estrutura primaria apresentou um composto de 8 resíduos de aminoácidos (RYPAVGYT). Esta molécula foi nomeada Lacraina. Entretanto na porção hidrofílica do extrato total de S. viridicornis e de Otostigmus cavalcanti foram observadas frações de baixa massa molecular com atividade antiparasítica contra Leishmania amazonensis e Trypanosoma brucei e antibacteriana contra E. coli e M. luteus. Também nesta fração foi observada uma molécula semelhante à Gomesina um peptídeo antimicrobiano da aranha caranguejeira Acanthoscurria gomesiana. A análise e caracterização desta molécula ainda esta em progresso. / Arthropods constitute the most diverse group in the Animal Kingdom, representing a very wide distribution in different ecosystems and habitats. The fact that these animals have changed very little during their evolution and that theyre well adapted to harsh environments with a high presence of pathogenic microorganisms, makes it interesting to conduct studies on their immune system. An important part of these systems are antimicrobial peptides that control the invasion of various pathogens. These molecules not only provide us with information on their immune system and its functioning, but can also help us find alternatives in the struggle against infectious diseases. Therefore, the purification and characterization of antimicrobial peptides present in these animals becomes important, as well as gaining knowledge on how their immune systems work. In this work two specimens of the Chilopoda order, Scolopendra viridicornis and Otostigmus cavalcanti, were used as an experimental model for the characterization of bioactive molecules present in the hemolymph and total body extract as well as the production of these molecules after stimulating or injuring the animal. The presence of different fractions with antimicrobial activity in the hemolymph (plasma and hemocytes) and the total body extract of defied and not defied animals in Otostigmus cavalcanti was observed. Presenting an increase in the antimicrobial activity in the stimulated group of animals, this could mean that some of the antimicrobial molecules are constitutively present in the animal, while others need to be induced to be expressed. In the plasma of S. viridicornis different fractions with antimicrobial activity and with activity against the Gram-negative bacteria E coli and against the C. albicans yeast were observed. Notwithstanding, in the hemocytes, there are different fractions that presented activity only against the Gram-positive M. luteus bacteria. In the hydrophobic portion of the total extract of the S. viridicorniss body, different fractions with anti-microbial activity were also observed. In the 5% ACN eluted material, by an ESI-MS analysis of a fraction with activity against M. luteus two molecules with low molecular mass (848.49 and 861.94 Da) were present and two pure molecules were observed in the total extract of the hydrophobic fraction. The first one presented a molecular mass of 1.7 kDa that remains to be characterized. The second one was a 925.4658 Da peptide, whose primary structure presented a compound of 8 amino acid residues (RYPAVGYT). This molecule was named Lacrain. However, in the hydrophilic portion of the total extract of S. viridicornis and O. cavalcanti low molecular mass fractions with antiparasitic activity against Leishmania amazonensis and Trypanosoma brucei as well as antibacterial activity against E. coli and M. luteus were observed. Also in this fraction a molecule similar to Gomesin, an antimicrobial peptide from the spider Acanthoscurria gomesiana. was present. The analysis and characterization of this molecule is still in progress.

Em artrópodes o sistema imune inato contribui para a adaptação de animais como os escorpiões à diferentes ambientes. Esse sistema é composto por mecanismos capazes de agir contra injúrias e a ação de microrganismos e entre esses mecanismos estão os peptídeos antimicrobianos (PAMs). O objetivo deste trabalho foi identificar PAMs presentes na hemolinfa de Tityus serrulatus. Para isso sua hemolinfa foi extraída e separados os hemócitos e plasma, em seguida fracionamos em 3 concentrações de acetonitrila em TFA 0,05% (05, 40 e 80%). Estas frações foram submetidas a uma cromatografia liquida de alta eficiência (CLAE) e os picos foram avaliados quanto a sua ação antimicrobiana e hemolítica. Foram identificadas 16 frações que apresentam atividade antimicrobiana. Uma das frações com atividade antimicrobiana, presente nos hemócitos apresentou similaridade com defensina descrita em carrapatos da espécie Ixodes scapularis. Essa fração possui aproximadamente 3486 Da, não apresenta atividade hemolítica e foi denominada como Serrulina. / In arthropods, its innate immune system contributes to the adaptation of animals like scorpions to different environments. This system consists of mechanisms that act avoiding injuries and against the action of microorganisms, among these mechanisms are antimicrobial peptides (AMPs). The aim of this study was to identify AMPs, present in the hemolymph of Tityus serrulatus. The hemolymph was extracted and then we separated hemocyte and plasma. The samples were fractionated in different concentrations of acetonitrile in TFA 0.05% (05, 40 and 80%). These fractions were subjected to high-performance liquid chromatography (HPLC) and the peaks obtained were evaluated for its antimicrobial and hemolytic action. We found sixteen fractions with antimicrobial activity. One of the fractions with antimicrobial activity, present in hemocytes, is similar with a defensin described in ticks, Ixodes scapularis. This fraction has about 3486 Da, has no hemolytic activity and was named as Serrulina.

Made available in DSpace on 2016-01-26T18:55:32Z (GMT). No. of bitstreams: 1 Cyntia Monteiro dos Santos.pdf: 278759 bytes, checksum: 7115571db1dd5d0d8d3833f1fb35c6f4 (MD5) Previous issue date: 2011-10-20 / The green tea derived from Camellia sinensis is considered a healthy drink, because it is associated with many benefits for the health, including the cancer prevention, cardiovascular disease and osteoporosis. The catechins are found abundantly in the green tea and they possess antioxidative, antibacterial and antitumoral activity, however there are not studies demonstrating if the chronic consumption of green tea could interfere in the reproduction and in biochemistry and hematological exams. Thus, the aim of this work is to verify the green tea influence in the weight, in the ovulation rate, in the blood count and in the blood biochemistry of superovulated rats. For that, the rats were divided in two groups, control and treated with green tea (n=30). The experiment had lost for three months, in the end of which 10 animals of each group were superovulated and sacrificed, after that, animals and the ovaries were weighted, corpora lutea were counted and the laboratorial exams of animals blood were realized. The chosen statistical analysis was the unpaired t test with Welch s correction and the moments in each group were analyzed by variance analysis with Tukey test, the differences were considered when p<0.05. The chronic consumption of green tea for three months avoid the increase of weight in animals with higher consumption and did not interfere with ovulation rate, but increased immune cells and lipid profile of the blood, and reduced serum creatinine in superovulated Wistar rats. / O chá verde oriundo da planta Camellia sinensis é considerado uma bebida saudável, pois está associado a vários benefícios para a saúde, incluindo a prevenção de câncer, doença cardiovascular e osteoporose. As catequinas encontradas em abundância no chá verde possuem ação antioxidativa e bactericida e também atividade anti-tumoral, porém não há estudos demonstrando se o consumo prolongado do chá verde pode interferir no corpo lúteo e nos parâmetros bioquímicos e hematológicos. Portanto, este trabalho teve como objetivo avaliar o peso corporal, o número de corpos lúteos, o hemograma e a bioquímica sérica de ratas Wistar superovuladas, sob ingestão prolongada de chá verde. Para tanto, as ratas foram divididas em dois grupos, controle e tratado com ingestão de chá verde (n=30). O experimento teve duração de três meses e ao final de cada mês, 10 ratas de cada grupo foram superovuladas e sacrificadas, foi realizada, então, a pesagem dos animais e dos ovários, a contagem dos corpos lúteos e a colheita de sangue para os exames laboratoriais. A análise estatística realizada entre os grupos foi o teste t não-pareado com correção de Welch e entre os momentos dentro de cada grupo empregou-se a análise de variância com contrastes pelo método de Tukey, diferenças foram consideradas quando p<0,05. O consumo prolongado do chá verde por três meses não aumenta o peso dos animais mesmo com maior consumo de ração, também não interfere na resposta ovulatória, porém, aumenta as células de defesa, diminui a creatinina sérica e aumenta o perfil lipídico do sangue em ratas Wistar superovuladas.

Made available in DSpace on 2016-07-18T17:53:09Z (GMT). No. of bitstreams: 1 Cyntia Monteiro dos Santos.pdf: 278759 bytes, checksum: 7115571db1dd5d0d8d3833f1fb35c6f4 (MD5) Previous issue date: 2011-10-20 / The green tea derived from Camellia sinensis is considered a healthy drink, because it is associated with many benefits for the health, including the cancer prevention, cardiovascular disease and osteoporosis. The catechins are found abundantly in the green tea and they possess antioxidative, antibacterial and antitumoral activity, however there are not studies demonstrating if the chronic consumption of green tea could interfere in the reproduction and in biochemistry and hematological exams. Thus, the aim of this work is to verify the green tea influence in the weight, in the ovulation rate, in the blood count and in the blood biochemistry of superovulated rats. For that, the rats were divided in two groups, control and treated with green tea (n=30). The experiment had lost for three months, in the end of which 10 animals of each group were superovulated and sacrificed, after that, animals and the ovaries were weighted, corpora lutea were counted and the laboratorial exams of animals blood were realized. The chosen statistical analysis was the unpaired t test with Welch s correction and the moments in each group were analyzed by variance analysis with Tukey test, the differences were considered when p<0.05. The chronic consumption of green tea for three months avoid the increase of weight in animals with higher consumption and did not interfere with ovulation rate, but increased immune cells and lipid profile of the blood, and reduced serum creatinine in superovulated Wistar rats. / O chá verde oriundo da planta Camellia sinensis é considerado uma bebida saudável, pois está associado a vários benefícios para a saúde, incluindo a prevenção de câncer, doença cardiovascular e osteoporose. As catequinas encontradas em abundância no chá verde possuem ação antioxidativa e bactericida e também atividade anti-tumoral, porém não há estudos demonstrando se o consumo prolongado do chá verde pode interferir no corpo lúteo e nos parâmetros bioquímicos e hematológicos. Portanto, este trabalho teve como objetivo avaliar o peso corporal, o número de corpos lúteos, o hemograma e a bioquímica sérica de ratas Wistar superovuladas, sob ingestão prolongada de chá verde. Para tanto, as ratas foram divididas em dois grupos, controle e tratado com ingestão de chá verde (n=30). O experimento teve duração de três meses e ao final de cada mês, 10 ratas de cada grupo foram superovuladas e sacrificadas, foi realizada, então, a pesagem dos animais e dos ovários, a contagem dos corpos lúteos e a colheita de sangue para os exames laboratoriais. A análise estatística realizada entre os grupos foi o teste t não-pareado com correção de Welch e entre os momentos dentro de cada grupo empregou-se a análise de variância com contrastes pelo método de Tukey, diferenças foram consideradas quando p<0,05. O consumo prolongado do chá verde por três meses não aumenta o peso dos animais mesmo com maior consumo de ração, também não interfere na resposta ovulatória, porém, aumenta as células de defesa, diminui a creatinina sérica e aumenta o perfil lipídico do sangue em ratas Wistar superovuladas.

Adult immunizations effectively reduce morbidity, mortality, and transmission rates of multiple diseases; however, outpatient providers often a struggle to convince patients to accept vaccinations. This project’s aim is to address vaccination rates in our adult population, focusing first on the influenza vaccine in year one (2016), and then on pneumococcal vaccine in year two (2017), by 1) using a strong quality improvement strategy (known as a Champion Team) and 2) implementing a clinic program consisting of provider training, improved documentation, and informative posters targeted at patients. A quality improvement strategy known as a “Champion Team” provided a strong mechanism through which we developed and implemented the interventions across both years. Specifically, the Champion Team consisted of key stakeholders (nurses, residents, physician faculty, and informatics expert) who identified, developed, and evaluated the program. Programming included an annual health care professional training session for each vaccine (early fall of 2016 and 2017 for flu, spring 2017 for pneumococcal), improved documentation strategies and nursing uptake, and informative posters in the clinic. We assayed data from our patient electronic health record to evaluate: the percentage of our patient population for whom an immunization was documented relative to the number of unique patients seen in our clinic during that time frame. This approach in year one showed a marked increase in influenza vaccination rates in our clinic. During the 2014/2015 and 2015/2016 flu seasons our clinic vaccination rates were 39.98% and 42.05% respectively. After implementation of our champion team and clinic wide program to increase rates in 2016 our vaccination rates for the 2016/2017 flu seasons was 50.88%. Pneumonia data for a full year are under analyses and will be included in this presentation. We anticipate a similar increase in rates for our pneumococcal vaccinations. Our Champion Team and clinic wide program were perceived as relatively low-effort interventions yet appeared to increase vaccinations over the course of this study. The replication of these findings across pneumonia data (pending) and, in future work, with the herpes zoster vaccine (planned for Year 3), will increase our confidence that increases in rates were attributable to these very accessible interventions.

This report describes the case of a 56-year-old man who presented with blurry vision, increased intraocular pressure, and conjunctival injection after posterior chamber intraocular lens implantation. Initially post-operative endophalmitis and foreign body inflammation were considered as differential diagnoses, but after further examination pan-uveitis was diagnosed. Uveitis is an ocular finding that may indicate several diseases, one of which is Behçet’s Disease. During the interview, the patient mentioned a history of apthous ulcers and genital ulcers which then lead to the clinical diagnosis of Behçet’s Disease. This report emphasizes that Behçet’s Disease is rare in Caucasians. Therefore, is frequently misdiagnosed in North America due to variable presentations and by not exploring the option when analyzing differential diagnoses. Early diagnosis and intervention will prevent the development of blindness and fatality due to complications of the disease.

Myeloid-derived suppressor cells (MDSC) expand during sepsis, suppress both innate and adaptive immunity, and promote chronic immunosuppression, which characterizes the late/chronic phase of sepsis. We previously reported that the transcription factors Stat3 and C/EBPb synergize to induces the expression of microRNA (miR)-21 and miR-181b to promote MDSC expansion in a mouse model of polymicrobial sepsis that progresses from an early/acute proinflammatory phase to a late/chronic immunosuppressive stage. We also showed that Gr1+CD11b+ cells, the precursors of MDSCs, from mice genetically deficient in the inflammatory protein S100A9 lack miR-21 or miR-181b in late sepsis, and are not immunosuppressive. In the present study, we show that S100A9 induces miR-21 and miR-181b during the late sepsis phase. We find that S100A9 associates with and stabilizes the Stat3-C/EBPb protein complex that activates the miRNA promoters. Reconstituting Gr1+CD11b+ cells from the S100A9 knockout mice with late sepsis with S100A9 protein restores the Stat3-C/EBPb protein complex and miRNA expressions, and switches the Gr1+CD11b+ cells into the immunosuppressive, MDSC phenotype. Importantly, we find that this process requires IL-10 mediated signaling, which induces S100A9 translocation from the cytosol to the nucleus. These results demonstrate that S100A9 promotes MDSC expansion and immunosuppression in late/chronic sepsis by inducing the expression of miR-21 and miR-181b.

Philosophiae Doctor - PhD / Cancer is a complex disease that involves a sequence of gene-environment interactions in a progressive process that cannot occur without dysfunction in multiple systems. From a mathematical point of view, the sequence of gene-environment interactions often leads to mathematical models which are hard to solve analytically. Therefore, this thesis focuses on the design and implementation of reliable numerical methods for nonlinear, first order delay differential equations, second order non-linear time-dependent parabolic partial (integro) differential problems and optimal control problems arising in cancer modeling. The development of cancer modeling is necessitated by the lack of reliable numerical methods, to solve the models arising in the dynamics of this dreadful disease. Our focus is on chemotherapy, biological stoichometry, double infections, micro-environment, vascular and angiogenic signalling dynamics. Therefore, because the existing standard numerical methods fail to capture the solution due to the behaviors of the underlying dynamics. Analysis of the qualitative features of the models with mathematical tools gives clear qualitative descriptions of the dynamics of models which gives a deeper insight of the problems. Hence, enabling us to derive robust numerical methods to solve such models. / 2021-04-30

Aunque el uso de altos niveles de fuentes de proteína vegetal en piensos para doradas de engorde se ha alcanzado con éxito en cuanto al crecimiento, estas dietas todavía están asociadas a efectos negativos en la eficiencia nutricional y en la capacidad inmunitaria. El intestino es el órgano donde se produce la primera interacción entre el pez, los nutrientes y las bacterias del medio, y desarrolla un papel crucial en la digestión de los nutrientes y la respuesta infamatoria e inmune. Esta tesis doctoral se centra en el impacto de distintas dietas con altos niveles de proteína vegetal, y especialmente, en la evaluación del estatus intestinal de las doradas de engorde alimentadas con altos niveles de sustitución de la harina de pescado durante un periodo largo de tiempo. Los cambios observados en el intestino se caracterizaron mediante el uso de distintas estrategias, como el análisis de la digestibilidad y la retención de amino ácidos, de la excreción de amonio, de la actividad de enzimas digestivos, de los cambios histológico o de la expresión de genes relacionados con la función y el mantenimiento de la arquitectura intestinal, así como técnicas ómicas para el análisis del proteoma y de la microbiota intestinal. Se ensayaron distintos niveles de sustitución de harina de pescado, pero el impacto de las dietas con una sustitución completa, bien complementada con subproductos de origen marino o suplementada con aminoácidos libres sintéticos, recibió mayor atención. La sustitución completa de la harina de pescado provocó una reducción, aunque ligera, del crecimiento y de la eficiencia digestiva y nutritiva de la dorada de engorde, aunque el impacto sobre el crecimiento era mayor cuando los peces eran alimentados desde la época de juveniles con estas dietas. La digestibilidad y el nivel de síntesis de proteína se vio alterada, aunque no se observaron diferencias significativas en la actividad enzimática digestiva. No obstante, el impacto de las fuentes vegetales cuando no había fuentes de proteína marina en la dieta era especialmente crítico para la supervivencia de los peces. En el intestino de estos peces solo se observaron diferencias menores relacionadas con la inflamación a nivel histológico, pero también se observó una disminución en la expresión génica de genes involucrados en la inflamación y la respuesta inmune. El análisis de la microbiota intestinal reveló cambios significativos en la composición de su composición, especialmente en el intestino posterior, sugiriendo una posible falta de capacidad de regular la respuesta inmune y de modular la colonización de bacterias patógenas tras un largo periodo de alimentación con esta dieta. Por otro lado, el análisis del proteoma de la mucosa intestinal también mostró un claro impacto sobre distintos procesos biológicos relacionados con el mantenimiento del homeostasis intestinal y de la integridad epitelial. Por el contrario, no se observó un impacto de la sustitución de la harina de pescado a nivel de expresión génica o del proteoma cuando se incorporaba a la dieta una fuente de proteína marina complementaria, aunque sí que se observaron algunos signos menores de inflamación. Por último, se desarrolló un sistema ex vivo para estudiar la respuesta inflamatoria e inmune de la mucosa intestinal a la presencia de distintas bacterias, y se realizó un ensayo preliminar en dorada para evaluar el efecto de la dieta sobre esta respuesta. En resumen, en este trabajo se ha realizado una evaluación extensa y detallada de los efectos a nivel intestinal de la inclusión de altos niveles de proteína vegetal en la dieta para doradas de engorde. Los resultados indican que las alteraciones en la capacidad inmune, la homeostasis y la microbiota intestinal aparecían solo cuando la proteína procedía exclusivamente de fuentes vegetales, y podrían explicar la mayor mortalidad registrada con esta dieta. / Malgrat que la utilització d'alts nivells de proteïna vegetal en pinsos per a dorades en la fase d'engreixament s'ha aconseguit amb èxit en quan al creixement, aquestes dietes encara s'associen amb freqüència amb efectes negatius en l'eficiència nutricional i la capacitat immunitària. L'intestí és l'òrgan on es produeix la primera interacció entre el peix, els nutrients de la dieta i les bactèries de l'ambient, i juga un paper fonamental en la digestió dels nutrients i en la resposta inflamatòria i immune. Aquesta tesi doctoral es centra en l'impacte de diferents dietes experimentals amb un alt nivell de proteïna vegetal, i especialment, en l'avaluació de l'estat de l'intestí de les dorades d'engreixament alimentades durant un llarg període amb alts nivells de substitució de farina de peix. Els distints canvis observats a nivell intestinal es van descriure mitjançant l'ús de distintes estratègies, com l'anàlisi de la digestibilitat i la retenció dels aminoàcids, de l'excreció d'amoni i de l'activitat enzimàtica, dels canvis histològic o de l'expressió de gens relacionats amb la funció i el manteniment de l'estructura intestinal, així com tècniques òmiques per a l'anàlisi del proteoma i de la microbiota intestinal. Es van assatjar diferents nivells de substitució de farina de peix, però l'impacte de les dietes amb substitució completa, bé complementada amb subproductes d'origen marí o suplementada amb aminoàcids lliures sintètics, va rebre major atenció. La substitució completa de la farina de peix va tenir un efecte lleugerament negatiu sobre el creixement i l'eficiència digestiva i nutritiva de la dorada d'engreixament, encara que l'impacte era major quan els peixos eren alimentats des de la fase de juvenils amb aquesta dieta. La digestibilitat i el nivell de síntesis de proteïna es va veure alterada, encara que no s'observaren diferències significatives en l'activitat dels enzims digestius. No obstant, l'impacte de les fonts vegetals quan s'eliminaven per complet les fonts de proteïna marina de la dieta era especialment crític en la supervivència dels peixos. En l'intestí d'aquests peixos sols s'observaren xicotets indicis d'inflamació a nivell histològic, però també es va observar una disminució l'expressió de gens involucrats amb el procés inflamatori i la resposta immune. L'estudi de la microbiota intestinal va revelar canvis significatius en la composició, especialment a l'intestí posterior, suggerint una possible falta de capacitat de regular la resposta immunitària i de modular la colonització per part de patògens després d'un llarg període d'alimentació amb aquesta dieta. D'altra banda, l'anàlisi del proteoma de la mucosa intestinal també va mostrar un impacte clar sobre diferents processos biològics relacionats amb el manteniment de l'homeòstasi intestinal i de la integritat de l'epiteli. Per contra, no es van observar un impacte de la substitució de la farina de peix a nivell d'expressió gènica o proteoma quan s'incloïa a la dieta una font complementària de proteïna d'origen marí, encara que sí que s'observaven alguns signes d'inflamació. Per últim, es va desenvolupar un sistema ex vivo per avaluar la resposta inflamatòria i immune de la mucosa intestinal davant la presència de diferents bactèries, i es va realitzar un assaig preliminar per determinar l'efecte de la dieta sobre aquesta resposta. En resum, en aquest treball s'ha realitzat una avaluació extensa i detallada dels efectes a nivell intestinal de la inclusió d'alts nivells de fonts de proteïna vegetal a les dieta per a les dorades d'engreixament. Els resultats indiquen que les alteracions en la capacitat immunitària, l'homeòstasi i la microbiota intestinal eren observades solament quan la proteïna era exclusivament obtinguda de fonts vegetals, i podrien explicar la major mortalitat observada amb aquesta dieta. / Although the inclusion of plant protein sources at high levels in aquafeeds for on-growing gilthead seabream has been successfully achieved on gilthead seabream in terms of growth, these diets are still associated to detrimental effects in feed efficiency and immune capacity. The intestine is the organ where takes place the first interaction of the host with dietary antigen or environmental bacteria, and plays a major role in the digestion of nutrients and the inflammatory and the immune response. The present PhD thesis focus on the impact of classical formulated high plant protein diets on fish performance, but especially, on evaluation of the intestinal status in on-growing fish long-term fed with high levels of fishmeal replacement. Changes at intestinal level were characterized by using different approaches, including protein and amino acid digestibility and retention and ammonia excretion, digestive enzyme activity, histology, expression of genes related with inflammation, immunity, structure and digestion, but also using whole tissue-level techniques for the analysis of the impact on proteome and gut microbiota. Different levels of fishmeal replacement were assayed, although the impact of diets with total replacement, complemented by inclusion of alternative marine by-products or supplemented by free amino acids, received greater attention. Total fish replacement produced a negative but minor impact on the growth and nutritive and digestive performance of on-growing gilthead seabream. Nevertheless, when fish were fed from juvenile stage with plant protein based diets, a higher negative impact in growth terms was noticed. Digestibility and metabolic use of amino acids was altered, but no differences were observed in the digestive enzyme activities. Nonetheless, feeding fish with total dietary fishmeal replacement by plant protein without any marine protein source was especially critical for survival rate. In these fish, gut histological assessment only revealed minor alterations related with an inflammatory response, but gene expression assay showed a down-regulation of several genes involved in the inflammatory and immune response. Moreover, a drastic change in the microbiota composition was observed, especially at the hindgut, revealing a possible lack of capacity to regulate a defensive response and to face with pathogen colonisation after a long-term coupling with these diet. Likewise, gut mucosa proteome analysis also suggests an impact on biological processes related with the maintenance of gut homeostasis and the epithelial integrity. In contrast, total fishmeal replacement did not induce alterations at transcript or proteomic level when diet was complemented with marine ingredients, although some minor inflammatory signs were reported. On the other hand, an ex vivo system to study the inflammatory and immune response of the gut mucosa to the presence of different bacteria was developed, and a preliminary assay evaluating the impact of the diet on this response was performed. To sum up, present works represents a wide assessment at intestinal level of the effects of including plant protein sources at high levels in aqua feeds for on-growing gilthead seabream. Results indicate that alterations in the immune capacity, the gut homeostasis and the microbiota were observed when protein was exclusively provided by plant sources, and could explain the higher mortality reported with this diet. / Estruch Cucarella, G. (2018). ASSESSMENT OF THE LONG-TERM IMPACT OF HIGH PLANT PROTEIN DIETS ON THE INTESTINAL STATUS OF THE ON-GROWING GILTHEAD SEA BREAM (Sparus aurata, L.) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/113063 / TESIS

This dissertation explores a new challenge to digital systems posed by the adaptation of mobile devices and proposes a countermeasure to secure systems against threats to this new digital ecosystem. The study provides the reader with background on the topics of spam, Botnets and machine learning before tackling the issue of mobile spam. The study presents the reader with a three tier model that uses machine learning techniques to combat spamming mobile Botnets. The three tier model is then developed into a prototype and demonstrated to the reader using test scenarios. Finally, this dissertation critically discusses the advantages of having using the three tier model to combat spamming Botnets. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Computer Science / unrestricted