ROS är ett produktnära system som stödjer planering och återrapportering i stålverket. Sandvik vill undersöka möjligheterna att modernisera användargränssnittet på detta system som idag är terminalbaserat till ett modernt grafiskt interface. Två metoder analyseras, den ena innebär att använda en kommersiell produkt för screen scraping och den andra metoden är Web Services Integration Toolkit som är freeware. Resultatet från analysen visar att Web Services Integration Toolkit klarar av att uppfylla de mål som är satta. En testkörning av Web Services Integration Toolkit görs också på ROS och resultat visar att metoden fungerar även fungerar i praktiken.

Este trabalho apresenta a modelagem matemática para um manipulador móvel composto por uma base móvel (o robô móvel Twil) e um manipulador (o manipulador WAM da Barrett). Os modelos cinemático e dinâmico para a base móvel, manipulador e manipulador móvel são apresentados. Como o manipulador móvel é um sistema não linear, uma estratégia de controle baseada em linearização por realimentação da dinâmica da plataforma seguida por uma transformação não suave para tratar a não holonomicidade do modelo cinemático é proposta. Então o método de backstepping é utilizado para obter as entradas do modelo dinâmico. Um controlador de torque calculado é proposto para o manipulador, Estas técnicas de controle são utilizadas simultaneamente para controlar o manipulador móvel. A implementação dos controladores propostos, na forma de plugins para o gerenciador de controladores é feita no ROS, assim os controladores são executados em tempo real. A maioria dos controladores existentes no ROS são do tipo SISO baseados em controle PID e independentes para cada junta, sendo que neste trabalho controladores MIMO não lineares são implementados. / This work presents a mathematical modelling for a mobile manipulator composed by a mobile base (the Twil mobile robot) and a manipulator (the Barrett WAM manipulator). The kinematic and dynamic models for the mobile base, the manipulator and the mobile manipulator are presented. As the the mobilie manipulator is a non-linear system, a control strategy based on feedback linearization of the platform dynamics followed by a non-smooth transform to handle the non-holonomicity of its kinematic model is proposed. Then, the backstepping method is used to obtain the inputs for the dynamic model. A computed torque controller is proposed for the manipulador. These control techniques are used simultaneously to control the mobile manipulator. The implementation of the proposed controllers is done in ROS as plugins for the controller manager so that the controllers run in real-time. Most controllers existing in ROS are independent joint SISO controllers based on the PID control law while in this work MIMO non-linear controllers are implemented.

Embora a cisplatina (cis-diaminocloroplatina II) seja um efetivo agente anticâncer, seu uso clínico é altamente limitado, predominantemente devido ao seu potencial nefrotóxico. Muitos estudos têm demonstrado que a cisplatina causa disfunção mitocondrial em células epiteliais renais e danos ao DNA nuclear devido à ação de espécies reativas de oxigênio tais como superóxido e radicais hidroxila. O aumento na produção destas espécies de oxigênio causa liberação de citocromo c no citosol, iniciando uma cascata de eventos que leva à morte celular por apoptose. A proteção seletiva da mitocôndria contra espécies reativas de oxigênio geradas pela cisplatina nos tecidos intactos tais como os rins, é fundamental na quimioterapia de pacientes com câncer. O presente estudo investigou os efeitos da cisplatina na bioenergética, no estado redox e no estresse oxidativo mitocondrial renal, bem como o potencial protetor da dimetiltiouréia (DMTU), um antioxidante seqüestrador de radicais hidroxila, com relação à toxicidade renal induzida pela cisplatina. Método: Ratos Wistar machos adultos pesando de 200 a 220 g foram divididos em quatro grupos de 8 animais cada. Ao primeiro grupo foi administrada cisplatina (10 mg/ kg) por via intra peritonial (i.p.). O segundo grupo recebeu somente injeções de DMTU (500 mg/kg, i.p., seguida de 2 injeções diárias de 125 mg/Kg, i.p). O terceiro grupo de animais foi tratado com DMTU (500 mg/kg, i.p.), imediatamente antes da injeção de cisplatina (10 mg/kg, i.p.), seguida de 2 injeções diárias de DMTU (125 mg/Kg, i.p.). O grupo controle recebeu somente solução salina (1ml/200g, i.p.). Os animais foram sacrificados 72 horas após a injeção de cisplatina (ou salina). Resultados: O tratamento com a cisplatina resultou em uma marcante diminuição da função renal demonstrada pela elevação dos níveis plasmáticos de uréia e de creatinina, concomitante a uma significativa alteração nos parâmetros relacionados à função Resumo ix mitocondrial (síntese de ATP, estado 3 da respiração, RCR, ADP/O, potencial de membrana e transporte de cálcio); ao estresse oxidativo mitocondrial (oxidação da cardiolipina, atividade da aconitase, lipoperoxidação, níveis de proteína carbonila e proteína sulfidrila); ao estado redox mitocondrial (oxidação do NAD(P)H, relação glutationa reduzida e glutationa oxidada) e à apoptose (atividade da caspase 3). O pré-tratamento dos animais com DMTU preveniu a falência renal aguda e as alterações dos parâmetros mitocondriais , sendo capaz de inibir a morte celular por apoptose. Conclusão: Os resultados demonstram o papel central da mitocôndria na falência renal aguda induzida pela cisplatina, bem como o efeito protetor do DMTU e sugerem que o desenvolvimento de potentes seqüestradores de radicais hidroxila, passíveis de uso clínico, poderia contribuir de forma marcante na prevenção dos danos renais resultantes da quimioterapia com este fármaco. / Although cis-diamminedichloroplatinum (II) (cisplatin) is an effective anticancer agent, its clinical use is highly limited predominantly due to its adverse effects on renal functions. Many studies have shown that cisplatin causes mitochondrial dysfunction and direct injury to nuclear DNA by generating reactive oxygen species such as superoxide and hydroxyl radicals. Overproduction of reactive oxygen species causes the release of cytochrome c into cytosol, thereby triggering the sequence of events leading to cell death via apoptosis. The selective protection of mitochondria against reactive oxygen species generated by cisplatin in intact tissues, such as kidney, is of critical importance in the chemotherapy of patients with cancer. The present study examined the effects of cisplatin on renal mitochondrial bioenergetics, redox state and oxidative stress as well as the protective potential of dimethylthiourea (DMTU), a hydroxyl radical scavenger, against the cisplatin-induced nephrotoxicity. Methods: Adult male Wistar rats weighing 200 to 220g were divided into 4 groups with 8 animals each.. The first group was given a single intraperitoneal (i.p.) injection of cisplatin (10 mg/kg). The second group was given only DMTU (500 mg/kg body weight, i.p, followed by intraperitoneal injections of 125 mg/Kg twice a day until sacrifice). A third group of animals was given DMTU (500 mg/kg body weight, i.p.), just before cisplatin injection (10 mg/kg body weight, i.p.), followed by intraperitoneal injections of DMTU (125 mg/Kg body weight) twice a day until sacrifice. The control group was treated only with saline solution (1ml/200g body weight, i.p.). Animals were sacrificed 72 hours after the treatment. Results: Cisplatin treated animals presented a marked impairment of the renal function evidenced by the elevation of plasmatic creatinine and urea levels simultaneously to a significant alteration of the parameters related to: (a) the mitochondrial function assessed by ATP synthesis, Summary xi state 3 respiration, RCR, ADP/O ratio, membrane potential, calcium uptake; (b) the mitochondrial oxidative stress assessed by cardiolipin oxidation, aconitase activity, lipid peroxidation, protein carbonyls and protein sulphydryl; (c) the mitochondrial redox state assessed by NADPH/NADP+ ratio, GSH/GSSG ratio and (d) apoptosis assessed by caspase-3 activity. DMTU substantially inhibited cisplatin-induced mitochondrial injury and cellular death by apoptosis, thereby suppressing the occurrence of acute renal failure. Conclusions: Results show the central role of the mitochondria in the cisplatin-induced renal acute failure, the protective potential of DMTU and suggest that the development of potent hydroxyl radical scavengers suitable for use in man could minimize the adverse effects of cisplatin in the kidney of patients under chemotherapy.

As condições divergentes do ambiente in vitro, como elevadas concentrações de sacarose, de reguladores de crescimento, de substâncias tóxicas, quando comparadas com o ambiente ex vitro, refletem-se em um desequilíbrio da relação entre compostos antioxidantes versus compostos oxidantes, resultando em elevada formação de espécies reativas de oxigênio, culminando no estabelecimento de um estresse oxidativo in vitro. No entanto, mesmo sendo capazes de conduzirem a morte celular, as espécies reativas de oxigênio atuam como importantes sinalizadoras do crescimento e desenvolvimento vegetal, por alterarem o padrão de expressão gênica, o metabolismo e a competência celular, sendo nesse aspecto considerado benéfico um nível moderado de estresse oxidativo para desencadear uma determinada rota morfogênica. Diante disso, o presente trabalho objetivou induzir o estresse oxidativo, suplementando o meio de cultura com reguladores de crescimento do grupo das citocininas e auxinas, com a finalidade de compreender a atuação deste evento nas respostas morfogênicas in vitro do pinhão manso (Jatropha curcas L.). Para tanto, utilizou-se sementes de pinhão manso de três procedências (CNPAE 101: Rio Verde, GO; CNPAE 115: Xambrê, PR e CNPAE 224: São Francisco do Glória, MG), as quais foram germinadas in vitro para a obtenção das plântulas e utilização do terço mediano do hipocótilo como explante nos experimentos de indução de estresse oxidativo in vitro. A análise morfofisiológica permitiu selecionar os tratamentos que induziram respostas organogênicas, que juntamente com o grupo controle, tiveram a quantificação da peroxidação lipídica, as atividades das enzimas antioxidantes catalase, superóxido dismutase e ascorbato peroxidase, determinadas, assim como o estabelecimento do perfil proteico de cada tratamento e a realização de análises histológicas e histoquímicas. Os resultados evidenciaram que as respostas morfogênicas foram dependentes do tipo e combinação de regulador de crescimento presente no meio de cultura; e ficou evidente pela quantificação da peroxidação lipídica e das atividades das enzimas antioxidantes, que a ausência de regulador de crescimento no meio de cultura foi o principal indutor do estresse oxidativo, permitindo constatar que quanto mais suave o estresse oxidativo, mais promissoras eram as respostas organogênicas constatadas nos explantes hipocotiledonares. Desta forma, o maior nível de estresse oxidativo constatado no grupo controle, relacionou-se negativamente com a resposta morfogênica obtida neste grupo, quando comparado aos demais tratamentos que apresentaram um nível de estresse oxidativo mais ameno e, consequentemente, uma resposta morfogênica mais promissora. O perfil proteico evidenciou o padrão existente de algumas bandas, independentemente da procedência considerada, confirmando a proximidade genética dos diferentes acessos de pinhão manso no Brasil. As análises histológicas demonstraram a ocorrência de organogênese indireta, com o desenvolvimento de calos organogênicos, ao passo que nas análises histoquímicas somente a presença de lipídios não foi detectada, enquanto proteínas totais, compostos fenólicos e amido foram constatados em pelo menos um dos três materiais analisados, para as três procedências de pinhão manso. Os resultados obtidos possibilitaram estabelecer uma relação entre o estresse oxidativo in vitro, a resposta morfogênica e o efeito dos reguladores de crescimento presentes no meio de cultura, além do potencial sucesso de produção de pinhão manso pela cultura de tecidos. / The environmental divergent conditions in vitro culture , such as high concentrations of saccharose , growth regulators, toxic substances, and others, when compared with the ex vitro conditions, reflected in an imbalance of antioxidants versus oxidant compounds relationship, resulting in an elevated formation of reactive oxygen species, which culminates in the establishment of an oxidative in vitro stress. However, even being able to conduce cell death, reactive oxygen species act as an important signaling of plant growth and development by altering the pattern of gene expression, cellular metabolism and cellular competence, being considerate beneficial in this context in which a moderate level of oxidative stress is required to trigger a morphogenetic route. Therefore, this study aimed to induce oxidative stress, supplementing the culture medium with growth regulators group of cytokines and auxin, with the purpose of understand the role of these event in vitro morphogenetic responses of physic nut (Jatropha curcas L.). Hence, were used physic nut´s seeds of three provenances (CNPAE 101: Rio Verde, GO; CNPAE 115: Xambrê, PR and CNPAE 224: São Francisco do Glória, MG ), which were in vitro germinated to obtain the seedlings and the middle third of hypocotyls that was used as explant in experiments to induction in vitro oxidative stress. The morphophysiological analysis allowed to select the treatments that induced the organogenic responses, which along with the control group, had the quantification of lipid peroxidation, activities of antioxidant enzymes catalase, superoxide dismutase and ascorbate peroxidase, determined as well as the establishment of the protein profile of each treatment and the realization of histological and histochemical analyses. The results showed that the morphogenic responses were dependent on the type and combination of growth regulators present in the culture medium; and with the lipid peroxidation quantification as well as antioxidant enzyme activities, it became evident that the oxidative stress was mainly caused by the absence of growth regulators in the culture medium, allowing noted that the softer oxidative stress, were the most promising responses organogenic found in hypocotyls. Thus, the higher level of oxidative stress observed in the control group correlated negatively with the morphogenic response obtained in this group when compared to the other treatments that showed a level of milder oxidative stress and, consequently, a more promising morphogenic response. The protein profile showed some band pattern, regardless of the provenances considered, confirming the low genetic distance between different accessions of Jatropha in Brazil. Histological analysis demonstrated the occurrence of indirect organogenesis, with the development of organogenic calli, whereas in histochemical analyzes only the presence of lipids was not detected while total proteins, phenolic compounds and starch were found in at least one of the three materials analyzed for the three provenances of physic nut. Taking together all the obtained data, it was possible to establish a relationship between oxidative stress, the morphogenic response in vitro and the effect of growth regulators in the culture medium as well as prove the potential success of the production of jatropha tissue culture.

Os genes relógio são responsáveis pelo ritmo circadiano e homeostase de diversos sistemas biológicos, incluindo o pâncreas endócrino. Nas células β são de grande importância para a regulação do metabolismo e da secreção de insulina (SI), e sua ausência pode levar ao desenvolvimento do diabetes. A NADPH oxidase (NOX) é um complexo enzimático responsável pela produção do ânion superóxido através da redução do oxigênio molecular. Em ilhotas pancreáticas, a NOX participa da regulação do metabolismo da glicose e da SI, através da modulação do estado redox intracelular. O objetivo do nosso estudo foi verificar se a desregulação dos genes relógio mediada pela ausência de Bmal1 seria capaz de modular a NOX e o estado redox nas células β pancreáticas, influenciando assim a SI. Observamos que a ausência de Bmal1 alterou a atividade e expressão da NOX, desregulando o estado redox intracelular. Essas alterações levaram à redução da viabilidade celular e mudanças na resposta à estimulação com glicose, resultando em uma deficiência na principal função da célula β a SI. / Clock genes are responsible for homeostasis and circadian rhythm in various biological systems, including endocrine pancreas. In β -cells, they are important for the regulation of metabolism and insulin secretion (IS), and its absence can lead to development of diabetes. NADPH oxidase (NOX) is an enzymatic complex responsible for production of superoxide anion by reducing molecular oxygen. In pancreatic islets, NOX regulates glucose metabolism and IS through modulation of the intracellular redox state. The aim of our study was to investigate whether dysregulation of clock genes mediated by Bmal1 suppression would be able to modulate NOX activity and redox state in pancreatic β cells, thus influencing the SI. In this work, the lack of Bmal1 altered the activity and expression of NOX, deregulating the intracellular redox state. These changes led to reduced cell viability and changes in cell response after stimulation with glucose, resulting in a deficiency in β cell main function, GSIS.

A luz solar apresenta ondas eletromagnéticas em ampla faixa espectral, incluindo as regiões do ultravioleta (UV-C, UV-B, UV-A), visível e infravermelho. Cada região interage com a pele de forma dependente da fotofísica e da fotoquímica dos seus respectivos compostos absorvedores. A luz UV-A causa a geração de espécies reativas de oxigênio e de nitrogênio (EROs e ERNs) através da fotossensibilização de moléculas endógenas (co-enzimas de flavina, porfirinas, melaninas). Quando fotossensibilizadores produzem quantidades de EROs e ERNs maiores do que a capacidade celular de supressão destas espécies, caracteriza-se um quadro de desbalanço redox, que causa lesão em biomoléculas como os ácidos nucleicos, lipídeos e as proteínas. Essas lesões podem levar à morte celular ou a outras transformações fenotípicas e genotípicas e também estimulam a liberação de citocinas pró-inflamatórias. Com a finalidade de melhor compreender a dinâmica dos mecanismos de resposta celular após exposição ao UV-A e ao visível, nós caracterizamos inicialmente as propriedades fotofísicas da melanina e detectamos a produção de oxigênio singlete (1O2) pela fotossensibilização no visível e a supressão desta espécie excitada pela reação do oxigênio singlete com a dupla ligação reativa dos grupos indóis presentes na melanina. Estes processos também foram observados no cabelo e levaram-nos a propor um modelo que explica o efeito da luz visível na estrutura e cor dos cabelos. Demonstramos também que a feomelanina produz mais (30%) 1O2 do que a eumelanina, que sofre maior modificação na sua estrutura por fotodegradação. O efeito destes processos na pele foi estudado a nível celular. Demonstramos que células epiteliais com maior teor de melanina apresentaram maior geração de 1O2 que causa lesão no DNA e morte necro-apoptótica após irradiação com luz visível. A foto-oxidação da melanina pela luz visível nos motivou a estudar um pigmento que fosse foto-protetor não somente contra luz UV-B mas também contra luz visível. A pigmentação com Acetil-Tirosina se mostrou atóxica e protetora contra luz UV-B e visível ao contrário do pigmento com tirosina, que se mostrou protetor do UV-B mas tóxico no visível. Este efeito foi relacionado com a localização celular do polímero e não com a estrutura do mesmo. A luz UV-A, por sua vez, promove o acúmulo de lipofuscina dentro dos vacúolos autofágicos de queratinócitos da pele e que também ativa a fototoxicidade pela luz visível. A lipofuscina dentro dos vacúolos autofágicos é foto-oxidada pela luz visível, causando lesão no DNA e morte celular programada tipo II. Doses UV-A que desencadeiam a liberação de citocinas também foram caracterizados. / Sunlight presents electromagnetic radiation over a wide spectral range, including the regions of ultraviolet (UV-C, UV-B, UV-A), visible and infrared. Each region interacts with skin dependending on the photophysics and photochemistry of the respective absorbing compounds. UV-A light causes the generation of reactive oxygen and nitrogen species (ROS and RNS) by photosensitization of endogenous molecules (flavin coenzymes, porphyrins, melanins). When photosensitizers produce amounts of ROS and RNS larger than the cell capacity to suppress these species, a set of redox imbalance, which damages biomolecules such as nucleic acids, lipids and proteins. This damage cause cell death and to other phenotypic and genotypic changes and also stimulates the release of proinflammatory cytokines. In order to better understand the dynamics of the mechanisms of cellular responses after exposure to UV-A and visible light, we initially characterized the photophysical properties of melanin and detected the production of singlet oxygen (1O2) by photosensitization in the visible, as well as the suppression of these excited species by reaction of singlet oxygen with the double bonds of the reactive groups presented in the melanin indols. These processes were also observed in hair and led us to propose a model that explains the effects of visible light on the structure and color of hair. We also demonstrated that pheomelanin produces more (30%) 1O2 than eumelanin, which undergoes a quick change on its structure by photodegradation. The effect of these processes in the skin was studied at the cellular level. We demonstrated that epithelial cells with larger melanin content have stronger generation of 1O2, which causes DNA damage and necro-apoptotic death after irradiation with visible light. The photo-oxidation of melanin by visible light has motivated us to study a pigment that was not only able to protect against UV-B but also against visible. Pigmentation with Acetyl-Tyrosine proved nontoxic and protective against UV-B and visible light instead of pigmentation with Tyrosine, which shielded against UV-B but showed toxicity in the visible. This effect was associated with the polymer, cell location and not with its structure. UV-A light, in turn, promotes the accumulation of lipofuscin, within autophagic vacuoles of keratinocytes also enabling phototoxicity in the visible light. The lipofuscin within the autophagic vacuoles is fotooxidized by visible light, causing DNA damage and programmed cell death type II. Linear dose of UV-A that trigger the release of cytokines were also characterized.

Introduction: As Information Technology (IT) becomes more and more advanced, the Enterprise System (ES) starts to attract researcher’s attention. While with the high rate of failure IT projects, it is important to evaluate the IT project properly. This paper conducts a case study in the Health Care area and chooses Jönköping County Council’s ROS system to be the target system. According to the established linkage between theory and real world organization, a practice of Enterprise System Evaluation is conducted by using an existing Uwizeyemungu et al.’s Enterprise System Effects Evaluation Model (ESEM). The research questions are as follows: What are the Enterprise Systems Effects which impact on business processes? To what extend do the ES effects impact on the business processes? Purpose: the study is an exploratory study that aims at identifying what are the ES Effects which impact on the business processes and assessing the importance and the actual degree of these effects. The answers of the first goal are explored by analyzing the documents and the record of interview, and the results are the basis of the second question. Method: This research has adopted a combined approach because of the nature of the research questions. Data has been collected through face-to-face interview, survey and the organizational documents. Secondary data are also be used for analyzing. Both qualitative and quantitative data are used for getting a reliable conclusion. Conclusions: The Enterprise System effects can be categorized into automaional effects, informational effects and transformational effects. The relationship between such effects and Performance indicators are very important. By determining the importance and impacts degree of such relationships, the evaluation results can be explicitly calculated and understood.

Autonomous system needs to do a great deal of reasoning during execution in order to provide timely reactions to changes in their environment. Data needed for this reasoning process is often provided through a number of sensors. One approach for this kind of reasoning is evaluation of temporal logical formulas through progression. To evaluate these formulas it is necessary to provide relevant data for each symbol in a formula. Mapping relevant data to symbols in a formula could be done manually, however as systems become more complex it is harder for a designer to explicitly state and maintain thismapping. Therefore, automatic support for mapping data from sensors to symbols would make system more flexible and easier to maintain. DyKnow is a knowledge processing middleware which provides the support for processing data on different levels of abstractions. The output from the processing components in DyKnow is in the form of streams of information. In the case of DyKnow, reasoning over incrementally available data is done by progressing metric temporal logical formulas. A logical formula contains a number of symbols whose values over time must be collected and synchronized in order to determine the truth value of the formula. Mapping symbols in formula to relevant streams is done manually in DyKnow. The purpose of this matching is for each variable to find one or more streams whose content matches the intended meaning of the variable. This thesis analyses and provides a solution to the process of semantic matching. The analysis is mostly focused on how the existing semantic technologies such as ontologies can be used in this process. The thesis also analyses how this process can be used for matching symbols in a formula to content of streams on distributed and heterogeneous platforms. Finally, the thesis presents an implementation in the Robot Operating System (ROS). The implementation is tested in two case studies which cover a scenario where there is only a single platform in a system and a scenario where there are multiple distributed heterogeneous platforms in a system. The conclusions are that the semantic matching represents an important step towards fully automatized semantic-based stream reasoning. Our solution also shows that semantic technologies are suitable for establishing machine-readable domain models. The use of these technologies made the semantic matching domain and platform independent as all domain and platform specific knowledge is specified in ontologies. Moreover, semantic technologies provide support for integration of data from heterogeneous sources which makes it possible for platforms to use streams from distributed sources.

Breast cancer is the most common cancer among Canadian women and 14-20% will develop lethal metastases within 5 years. A potential novel therapeutic target is Focal Adhesion Kinase (FAK), a cytoplasmic tyrosine kinase. FAK’s expression is inversely correlated with survival and is known to regulate cell migration, proliferation and invasion. While tyrosine kinase inhibitors are historically ineffective as single agents, they are commonly used as part of combination therapies. Therefore, given its central role in tumor cell biology and cell signaling, we hypothesized that inhibiting FAK in combination with pharmacological agents commonly used to treat metastatic breast cancer patients will result in enhanced anti-tumor activity. We combined a commercial FAK inhibitor (PF-562271) with a range of chemotherapeutic agents commonly used to treat metastatic breast cancer and searched for synergistic partners. Only DNA topoisomerase inhibitors showed potential to synergistically reduce cell viability when paired with low doses of the FAK inhibitor. However, the combination does not induce an increase in cell death or apoptosis. It was then discovered that both agents in isolation and in combination produce increased levels of ROS, a toxic metabolite. This, along with other more preliminary data, provides clues for a novel proposed mechanism of action for this interaction.

Mitochondria are essential for the viability of mammalian cells and provide a compartment for specific chemical reactions. Cellular respiration -- the main mitochondrial function -- is tightly connected with ROS production: the mitochondrial electron transport chain complexes I and III are the main ROS sources in mammalian cells. It has been reported that complex I and complex III activities are essential for cell cycle, apoptosis and stem cell differentiation (Spitkovsky et al., 2004; Varum et al., 2009; Lee et al., 2011; Ma et al., 2011; Tormos et al., 2012). In our work, we aimed to investigate the role of mitochondrial electron transport chain activity in the regulation of the differentiation potential and to unravel signaling pathways that could participate in this regulation. As a model, we used the P19 pluripotent stem cell line that can be easily differentiated into trophoblasts, expressing intermediate filaments cytokeratin 8/18, and neurons, which express cytoskeleton protein beta-III-tubulin. We first showed that both trophoblast and neural differentiation of P19 cells were accompanied by activation of cellular respiration. The analysis of respiratory chain complexes and supercomplexes, however, showed that undifferentiated P19 cells, as well as their differentiated derivatives did not differ in their respiratory machinery, including functional respirasomes. While undifferentiated cells did not use respiration as the main energy source, cellular respiration was activated during differentiation, indicating that oxidative metabolism was important for efficient differentiation. To investigate the potential role of mitochondrial electron transport chain activity we monitored the influence of a disrupted electron flow on the differentiation of P19 cells. We found that the activity of complex I and complex III influenced the differentiation potential of the pluripotent P19 cell line: the presence of complex I and complex III inhibitors rotenone, antimycin A, or myxothiazol increased the amount of cytokeratin 8/18+ cells during trophoblast differentiation, but almost completely prevented the formation of neuron-like beta-III-tubulin+ cells during neuron differentiation. Moreover, a low oxygen level (1 % O2 vs 21 % O2 in atmosphere) - the final electron acceptor - had the same effect on differentiation. These data suggest that mitochondrial electron transport chain activity contributes to the regulation of differentiation. The presence of complex I and complex III inhibitors, as well as oxygen scarcity, increase ROS production. We suggested that increased ROS level could explain the observed effects. By visualizing mitochondrial superoxide production with a specific dye – MitoSox - we confirmed that rotenone, antimycin A, myxothiazol, as well as low oxygen conditions, increased the superoxide level. These results suggest that the observed changes of the differentiation potential of P19 cells are associated with ROS production. To prove this idea, we differentiated P19 cells in presence of paraquat – a known ROS inducer. In line with our hypothesis paraquat promoted trophoblast differentiation. The received results suggest that the mitochondrial electron transport chain activity regulates differentiation through the ROS level. ROS are secondary messengers that participate in numerous processes including cell proliferation and differentiation. We aimed to predict the signal pathway that connects ROS level in stem cells and their differentiation potential. For this purpose, we performed a microarray analysis and compared the gene expression profiles of cells grown under hypoxia or in the presence of the complex III inhibitor myxothiazol with untreated control cells. The expression analysis revealed p53 as a transcriptional factor that impacts the differentiation potential in treated cells. p53 is a known redox-sensing molecule (Bigarella et al., 2014) that influences the differentiation potential through cell cycle control (Maimets et al., 2008). This observation is in line with our results and suggests that p53 may regulate the differentiation potential of P19 cells. We are planning to investigate the role of p53 signaling in the regulation of cell cycle and differentiation potential of P19 cell line.