Há muitas alterações nos sistemas fisiológicos de indivíduos com diabetes melittus em função dos constantes momentos de hiperglicemia, principalmente alterações relacionadas ao aumento dos riscos cardiovasculares. O objetivo desse estudo foi avaliar as respostas do controle glicêmico pelo monitor contínuo de glicose e da pressão arterial (PA), frequência cardíaca (FC) e sua variabilidade expressa pelos valores de RMSSD em diabéticos tipo II submetidos a testes de avaliação antes e após a realização de treinamento aeróbio e resistido. Participaram desse estudo 9 voluntários diabéticos tipo II do sexo masculino (45 a 65 anos) divididos em 3 grupos: DTA (n=7), diabéticos submetidos a seis semanas de treinamento aeróbio; DTR (n=5), diabéticos submetidos a treinamento resistido e GDC (n=5), diabéticos sem qualquer treinamento regular. Os voluntários realizaram testes laboratoriais, ergoespirometria e teste de fadiga em leg press antes e após o treinamento físico. Os resultados foram analisados estatisticamente pelo teste t de Student e pelo teste de Kruskal Wallis. Os voluntários tiveram a cinética da concentração de glicose mensurada pelo monitor contínuo e analisada qualitativamente antes, durante e após a realização da ergoespirometria e do teste de fadiga por 60 minutos. Como resultados o grupo DTA apresentou menores valores de concentração de glicose pela monitorização contínua e o grupo DTR a melhor resposta na cinética dessa curva, apresentando expressivo decaimento na mesma. Em relação à resposta pressórica, somente a PA diastólica (PAD) foi menor estatisticamente para o grupo DTA pós treinamento aeróbio no repouso. Não houve diferenças entre os valores pré e pós treinamentos em relação à FC e os voluntários do grupo DTA apresentaram maiores valores de RMSSD em repouso e o do grupo DTR incrementos desses valores na recuperação dos testes, mostrando maior ação parassimpática no controle autonômico cardíaco dos diabéticos submetidos a treinamentos. Os indivíduos do grupo GDC apresentaram decremento nesse valor, sugerindo piora no controle autonômico cardíaco. Como conclusão geral, este estudo sugere que indivíduos diabéticos tipo II que realizaram treinamento aeróbio e resistido apresentaram benefícios complementares no controle glicêmico registrado pelo monitor contínuo em repouso e no período de recuperação de exercício, respectivamente, adaptações que parecem estar associadas à melhora da ação parassimpática/vagal no controle autonômico cardíaco e, sugere, também, ser o treinamento físico aeróbio o que permite melhor organização hemodinâmica nas respostas de PAD. / There are many changes in physiological systems of people with diabetes melittus due to the constant moments of hyperglycemia, mainly related to increasing of cardiovascular risk. The aim of this study was evaluate the responses of glycemic control by continuos glucose monitoring and blood pressure (BP), heart rate (HR) and its variability expressed by the values of RMSSD in type II diabetics undergoing evaluation tests before and after performing aerobic and resistance training. Participants were 9 volunteers type II diabetic male (45-64 years) divided in 3 groups: DTA (n=7), diabetics undergoing six weeks of aerobic training; DTR (n=5), diabetics undergoing resistance training and GDC (n=5), diabetics without any regular training. The volunteers underwent laboratory tests, spirometry and fatigue tests on leg press before and after physical training. The results were statistically analyzed by Students t and Kruskal Wallis tests. The volunteers had the kinetics of glucose concentration measured by the continuos monitor and qualitatively analyzed before, during and after the spirometry and the fatigue tests for 60 minutes. As a result the DTA group had lower glucose concentration by continuos monitoring and DTR the best response in the kinetic curve, showing important decrease in it. In relation to the BP response, only diastolic BP (DBP) was statistically lower for the DTA group after aerobic training. There were no differences between pre and post training in HR and the DTA group showed higher RMSSD at rest and the DTR group showed increments of these values in the tests recovery showing higher parasympathetic action on cardiac autonomic control in diabetics patients with training. Individuals in the GDC group showed decrement this value, suggesting deterioration in cardiac autonomic control. As a general conclusion, this study suggests that type II diabetic individuals who performed aerobic and resistance training showed additional benefits in glycemic control by continuos monitor recorded at rest and during exercise recovery, respectively, adaptations that seem to be associated with improvement in parasympathetic action in cardiac autonomic control, and also suggests that aerobic exercise training has better organization hemodynamic in responses of DBP.

Submitted by Joana Azevedo (joanad@id.uff.br) on 2017-08-24T17:22:16Z No. of bitstreams: 1 Dissert Junio vasconcelos Soares.pdf: 1084625 bytes, checksum: 172ec4f2f7210e54f3768d817d768111 (MD5) / Approved for entry into archive by Biblioteca da Escola de Engenharia (bee@ndc.uff.br) on 2017-09-18T13:57:36Z (GMT) No. of bitstreams: 1 Dissert Junio vasconcelos Soares.pdf: 1084625 bytes, checksum: 172ec4f2f7210e54f3768d817d768111 (MD5) / Made available in DSpace on 2017-09-18T13:57:36Z (GMT). No. of bitstreams: 1 Dissert Junio vasconcelos Soares.pdf: 1084625 bytes, checksum: 172ec4f2f7210e54f3768d817d768111 (MD5) Previous issue date: 2017-03-27 / A presente pesquisa teve por objetivo identificar a visão de gestores de pessoal, gestores médicos e gestores enfermeiros sobre a maturidade da Gestão de RH e sobre o comprometimento organizacional dos funcionários dos hospitais da cidade de Muriaé (MG). Nesse sentido, buscou-se não apenas identificar a percepção dos gestores hospitalares em relação aos dois construtos, mas compreender, através dos elementos presentes em seus discursos, a relação entre a face de RH em que os hospitais se encontram e o tipo de comprometimento apregoado pela literatura. A investigação ocorreu por meio de um estudo qualitativo, em que se utilizou a estratégia de análise do conteúdo no tratamento do material. Os dados foram coletados em uma pesquisa de campo através de entrevistas com os referidos gestores utilizando-se um roteiro semiestruturado. Os resultados encontrados nesta pesquisa mostraram que, das quatro instituições hospitalares da cidade, uma tem sua maturidade de RH na face de execução; duas, na face de construção; e uma na face de realinhamento. No que diz respeito ao comprometimento de seus funcionários, uma instituição hospitalar apresentou a característica unidimensional do comprometimento instrumental, e as outras três apresentaram elementos multidimensionais do comprometimento, com características do comprometimento afetivo e do comprometimento instrumental. Os achados no campo serão de grande valia para as organizações, para o segmento hospitalar de modo geral e também para a academia. Inclusive sugere-se que o estudo seja replicado em outros segmentos organizacionais e outras regiões brasileiras. A título de conclusão, com base na análise do discurso dos gestores entrevistados, foram feitas inferências sobre a relação entre a face de RH em que os hospitais muriaeenses se encontram e o tipo de comprometimento apregoado pela literatura, e pôde-se perceber que todos os hospitais da cidade passam por um processo de organização do órgão responsável pela GP, estando num processo de amadurecimento dessa gestão, que pode, em médio prazo, aumentar o nível de comprometimento organizacional dos funcionários que atuam nessas instituições. / The present research had the objective of identifying the view of personnel managers, medical managers and nurses managers on the maturity of HR Management and on the commitment of hospital employees in the city of Muriaé - MG. It was sought not only to identify the perception of the hospital managers in relation to the two constructs, but to understand through the elements present in their speeches the relation between the face of HR in which the hospitals are and the type of commitment touched by literature. The research was carried out through a qualitative study that used the strategy of content analysis in the treatment of material that was collected through interviews with said managers using a semi-structured script in a field research. The results found in the present study showed that one of the four hospital institutions in the city has its HR maturity in the face of execution, two in the face of construction and one in the face of realignment; And with regard to the commitment of its employees, one hospital institution presented the one-dimensional characteristic of the instrumental commitment and the other three presented multidimensional elements of the commitment, with characteristics of the affective commitment and the instrumental commitment. The findings in the field will be of great value to the organizations, to the hospital segment in general and also to the academy, it is even suggested that the study be replicated in other organizational segments and other Brazilian regions. As a conclusion, inferences were drawn, based on the analysis of the interviewees' discourse, about the relationship between the HR face in which the hospitals in muriaeenses meet and the type of commitment touched by the literature, and it was possible to perceive that all Hospitals in the city are undergoing a process of organization of the body responsible for GP, being in a process of maturation of this management, which in the medium term can increase the level of organizational commitment of the employees who work in these institutions.

The aim of this thesis is to analyze and evaluate the current situation of the education system in the company BAEST Machinery Holding, Inc. Minor task is to map all steps of the education process in the concrete company with its strengths and weaknesses. To find out more about employee's satisfaction or dissatisfaction with corporate training was used a questionnaire survey that unfold skills development perception of course participants. The work is divided into theoretical and analytical part. The first mentioned contains human resources activities and stuff training described in detail steps together with methods and subjects. The theoretical block also contains results of the surveys carried out in the field of education in the ČR and abroad. The second part of this thesis is devoted to analyzing the education system in BAEST Machinery Holding, Inc. The introduction of the company is followed by the current situation of education in the firm. In detail are analyzed the steps of the systematic training cycle and published opinions of the employees in the form of survey results. In the conclusion are the proposals and recommendations to improve the educational activities of the company.

A represa Billings é o maior reservatório de água que abastece o estado de São Paulo. Está localizada na bacia do Alto Tietê na região metropolitana de São Paulo, em uma área de proteção ambiental. Contudo, desde o início da sua inundação, vem sofrendo sérias agressões ambientais. Entre elas, o fluxo de entrada de água do rio Pinheiros, usado para controle de enchentes na região metropolitana de São Paulo. A constante entrada de contaminantes na represa se torna preocupante, considerando que, no seu entorno, há diferentes tipos de assentamentos, entre os quais de famílias de pescadores, que usam estas águas sem tratamentos convencionais para consumo doméstico e pesca artesanal para subsistência. Portanto, este estudo teve como objetivo realizar uma avaliação temporal dos níveis de metais presentes na água e em tecidos dos peixes da represa, correlacionando estes valores com o fluxo de entrada de água do rio Pinheiros e do índice pluviométrico na região. Durante o período de um ano, cerca de 800 indivíduos, dentre as principais espécies de peixes consumidas na região Geophagus brasiliensis (acará), Hoplias malabaricus (traíra), Tilapia rendalli (tilápia) e Astyanax ssp (lambari), de sete pontos de pesca, foram coletadas e analisados. Amostras de águas foram coletadas em 13 pontos sugeridos pelos pescadores locais. Considerando cada espécie de peixe analisada, os níveis de metais estão na mesma ordem de magnitude, independentemente da região de captura. Os níveis de Cr, em cerca de 60% dos acarás, 98% dos lambaris, 67% dos traíras e 100% de tilápia não atenderam ao limite estabelecido pela ANVISA. Cu e Hg, em todas as amostras atenderam aos limites estabelecidos pela legislação nacional. A inserção das águas do rio Pinheiros claramente afeta a qualidade da água da represa. As regiões mais contaminadas são: Pedreira, Margem do Bororé, Alvarenga, Barragem Taquacetuba, Casa Caída e Ilha do Biguá. Observou-se também que 100% de amostras não atendem ao limite estabelecido pelo CONAMA; para Cu, Mn, Ni, cerca de 50% não cumprem o limite estipulado para Cd e 20% para Zn. Em linhas gerais, observou-se que esta inserção altera todo o regime natural da represa, mas que ainda assim é possível absorver a contaminação recebida. / The Billings Dam is the largest reservoir of water that supplies in the state of São Paulo. It is part of the Alto Tiete basin, which is located in the metropolitan region of São Paulo in an environmentally protected area. In spite of that, since the beginning of its flooding, several environmental aggressions were observed. Among them the inflow of water from Pinheiros river, used to control floods in the metropolitan region of Sao Paulo .The constant input of contaminants in the dam becomes worrisome, considering that, in its surroundings, there are different kinds of settlements, among them families of fishermen, who use these waters without conventional treatments for domestic consumption and artisanal fishing for livelihood. Therefore, this study aimed to carry out a temporal evaluation of metal levels present in dam\'s water and fish tissue, correlating these values with the water input flow of Pinheiros River and pluviometric index in the region. During a period of one year, circa of 800 individuals among the main consumed fish species in the region Geophagus brasiliensis (acará), Hoplias malabaricus (traíra), Tilapia rendalli (tilápia) e Astyanax ssp (lambari), from seven fishing places were collected and analysed. It was also collected water from thirteen places chosen by local fishermen. Considering each fish specimen analyzed, the levels of metals are in the same order of magnitude regardless of the region of capture. The levels of Cr in circa of 62% of acarás, 98% of lambaris, 67% of traíras and 100% of tilapia do not meet the limit stipulated by ANVISA. Cu and Hg, in all samples meet the limits set by national legislation. The Pinheiros river water clearly affects the quality of dam\'s water. The most contaminated regions were: Pedreira, Margem do Bororé, Alvarenga, Barragem Taquacetuba, Casa Caída and Ilha do Biguá. It was observed that 100% of samples do not meet the limits established for water quality by CONAMA for Cu, Mn and Ni, 50% do not meet the limit for Cd and 20% for Zn . In general, we can observe the entry of to the waters of Pinheiros River during operation of the flotation system and even during the flood control changes the whole natural scheme of the dam, although the dam still manages to absorb the contamination that is received.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-09-19T16:40:07Z No. of bitstreams: 1 2017 - Joice de Oliveira Epif?nio da Silva.pdf: 1763397 bytes, checksum: 44313e9004a2f56196454eef89822e7d (MD5) / Made available in DSpace on 2018-09-19T16:40:07Z (GMT). No. of bitstreams: 1 2017 - Joice de Oliveira Epif?nio da Silva.pdf: 1763397 bytes, checksum: 44313e9004a2f56196454eef89822e7d (MD5) Previous issue date: 2017-07-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Law No. 8213/91, known as the Quota Law was formulated as a tool to implement the National Policy on Employment Dues for Persons with Disabilities. This law today is one of the main means for the insertion of PCDs (Persons with Disabilities) into the labor market. However, the implementation of this law occurs in the face of some difficulties, such as accessibility, for example, in addition to prejudice regarding PCDs in the social environment, which ultimately interferes with its effectiveness. The purpose of this paper is to understand the meanings attributed to the Quota Law by HR Managers who act or have acted in organizations that apply the Quota Law. In order to achieve this goal, nine interviews were conducted, of which eight interviews were conducted with managers, some of whom were in full exercise until the date of the interview, and others who had recently left the organization in which they performed HR functions, and was also interviewed the coordinator of the State Nucleus for Assistance to the Disabled (NEAD). Besides the interviews, this work made use of the technique of observation and the analysis of the collected material occurred through the Nuclei of Meaning. The results show that the managers interviewed still perceive the Quota Law as a merely punitive Law, however, they understand the Quota Law also, as an important one, if not unique, tool for the insertion of PCDs into the labor market. With this, it can be said that the meanings that managers attribute to the Quota Law are loaded with prejudice and the way the Quota Law is signified by these managers reflects in the way they execute this Law, and it can be affirmed that the issue is cultural. / A lei n? 8213/91, conhecida como Lei de Cotas foi formulada como ferramenta para implementar a Pol?tica Nacional de Cotas Empregat?cias para Portadores de Defici?ncia. Esta lei hoje ? um dos principais meios para a inser??o das PCDs (Pessoas com Defici?ncia) no mercado de trabalho. Contudo, a implementa??o desta lei ocorre diante de algumas dificuldades, como a acessibilidade, por exemplo, al?m do preconceito no que tange ?s PCDs no meio social, o que acaba interferindo na efetividade da mesma. Este trabalho tem como objetivo, compreender os sentidos atribu?dos ? Lei de Cotas pelos Gestores de RH que atuam, ou atuaram, em organiza??es que se aplica a Lei de Cotas. Para atingir este objetivo foram realizadas nove entrevistas, sendo oito entrevistas realizadas com gestores, dos quais alguns estavam em pleno exerc?cio da fun??o at? a data da entrevista e outros que haviam sa?do recentemente da organiza??o em que exercia a fun??o de gestor de RH, e ainda, foi entrevistada a coordenadora do N?cleo Estadual de Atendimento ao Deficiente (NEAD). Al?m das entrevistas este trabalho fez uso da t?cnica de observa??o e a an?lise do material levantado ocorreu por meio dos N?cleos de Significa??o. Os resultados mostram que os gestores entrevistados ainda percebem a Lei de Cotas como uma Lei meramente punitiva, entretanto, entendem a Lei de Cotas tamb?m, como uma importante, sen?o ?nica, ferramenta para a inser??o das PCDs no mercado de trabalho. Com isso, pode-se afirmar que os sentidos que os gestores atribuem a Lei de Cotas s?o carregados de preconceito e a forma como a Lei de Cotas ? significada por esses gestores reflete na forma como executam essa Lei, e ainda, pode-se afirmar que a quest?o ? cultural

We present new radio/millimeter measurements of the hot magnetic star HR 5907 obtained with the VLA and ALMA interferometers. We find that HR 5907 is the most radio luminous early type star in the cm–mm band among those presently known. Its multi-wavelength radio light curves are strongly variable with an amplitude that increases with radio frequency. The radio emission can be explained by the populations of the non-thermal electrons accelerated in the current sheets on the outer border of the magnetosphere of this fast-rotating magnetic star. We classify HR 5907 as another member of the growing class of strongly magnetic fast-rotating hot stars where the gyro-synchrotron emission mechanism efficiently operates in their magnetospheres. The new radio observations of HR 5907 are combined with archival X-ray data to study the physical condition of its magnetosphere. The X-ray spectra of HR 5907 show tentative evidence for the presence of non-thermal spectral component. We suggest that non-thermal X-rays originate a stellar X-ray aurora due to streams of non-thermal electrons impacting on the stellar surface. Taking advantage of the relation between the spectral indices of the X-ray power-law spectrum and the non-thermal electron energy distributions, we perform 3-D modelling of the radio emission for HR 5907. The wavelength-dependent radio light curves probe magnetospheric layers at different heights above the stellar surface. A detailed comparison between simulated and observed radio light curves leads us to conclude that the stellar magnetic field of HR 5907 is likely non-dipolar, providing further indirect evidence of the complex magnetic field topology of HR 5907.

In this paper we investigate the multiwavelengths properties of the magnetic early B-type star HR7355. We present its radio light curves at several frequencies, taken with the Jansky Very Large Array, and X-ray spectra, taken with the XMM X-ray telescope. Modeling of the radio light curves for the Stokes I and V provides a quantitative analysis of the HR7355 magnetosphere. A comparison between HR7355 and a similar analysis for the Ap star CUVir, allows us to study how the different physical parameters of the two stars affect the structure of the respective magnetospheres where the non-thermal electrons originate. Our model includes a cold thermal plasma component that accumulates at high magnetic latitudes that influences the radio regime, but does not give rise to X-ray emission. Instead, the thermal X-ray emission arises from shocks generated by wind stream collisions close to the magnetic equatorial plane. The analysis of the X-ray spectrum of HR7355 also suggests the presence of a non-thermal radiation. Comparison between the spectral index of the power-law X-ray energy distribution with the non-thermal electron energy distribution indicates that the non-thermal X-ray component could be the auroral signature of the non-thermal electrons that impact the stellar surface, the same non-thermal electrons that are responsible for the observed radio emission. On the basis of our analysis, we suggest a novel model that simultaneously explains the X-ray and the radio features of HR7355 and is likely relevant for magnetospheres of other magnetic early type stars.

L'objet de ma thése est la conception rationnelle d'une bobine utilisable par une sonde de RMN pour des échantillons solides d'origine biologique, tels que les milieux membranaires ou les biopsies. L'étude de la distribution du champ électromagnétique créée pendant l'impulsion radiofréquence s'est avérée indispensable pour permettre d'une part une meilleure homogénéité du champ B1 et d'autre part une redistribution du champ électrique dans un plan normal à l'axe principal de la bobine. Auparavant, cette distribution de champ avait été considérée homogène au centre de l'échantillon, et seule la composante axiale était prise en compte. La démarche scientique suivie ici est originale en cela qu'elle se sert d'une résolution numérique des équations de Maxwell, et permet la mise en évidence des composantes radiales du champ B1 jusqu'alors ignorées. La première partie présente les caractéristiques instrumentales de la méthode HR-MAS. Il s'en suit une partie plus théorique sur les concepts d'électromagnétisme nécessaires pour aborder la cartographie de champ radiofréquence B1 dans une bobine. Ce travail utilise une résolution de l'équation maîtresse de l'évolution des spins (Liouville von Neumann) où l'Hamiltonien de champ B1 est construit en tenant compte de la forme particulière du champ magnétique dans une bobine hélicoïdale. Une étude de l'impact du champ électrique sur un échantillon aqueux dispersif est introduite dans la quatrième partie. Finalement une bobine innovante a été conçue, celle-ci permet d'éloigner le champ électrique du centre de l'échantillon, où le champ magnétique est dominant et homogène ses performances sont décrites à travers une série d'expériences sur les bicelles.

No description available.

Homologous recombination (HR) is a highly conserved cellular process involved in the maintenance of chromosomal integrity and generation of genetic diversity. Biochemical and genetic studies have suggested that HR is crucial for repair of damaged DNA arising from various endogenous or exogenous assaults on the genome of any organism. Further, HR is vital to repair fatal DNA damage during DNA replication. An instructive example of cross-talk between the processes of DNA recombination and replication can be construed in the processing of replication/recombination/repair intermediates. The impediment(s) to the progression of DNA replication fork is one of the underlying causes for increased genome instability and consequently this might compromise the survival of organism. Various processes manifest at stalled replication forks before they can be rendered competent for the replication-restart. One of the mechanisms of replication-restart involves replication fork reversal (RFR), which envisage unwinding of the blocked forks with simultaneous annealing of the parental and daughter strands o generate a Holliday junction intermediate adjacent to DNA double strand end. Genetic evidence shows that in E. coli dnaEts mutant, holD mutant and in helicase defective rep mutant, RFR is catalyzed by RuvAB complex. Classically, HJ intermediates are generated during the terminal stages of the HR pathway. In E. coli, branch migration and resolution of HJ intermediates is promoted by RuvA, RuvB and RuvC proteins, which participate at the late stages of HR. Structural, biochemical and mutational analysis suggest that E. coli RuvA binds Holliday junction DNA with high affinity and specificity. RuvB, a member of the AAA+ (ATPase associated with various cellular activities) family, is recruited to the RuvA-Holliday junction complex and functions as a motor protein. Together, RuvA and RuvB catalyze ATP dependent branch migration of HJ. The resolution of HJ is catalyzed by the RuvC endonuclease, which introduces coordinated cuts at two symmetrical sites across the junction. RuvAB complex, the Holliday junction branch migration apparatus, is ubiquitous in bacteria. Genetic, biochemical and structural studies have not only established the in vivo role of E. coli RuvAB, in context of HR pathway, but have also provided valuable insights into the mechanism of HJ processing by RuvAB complex. However, the paucity of extensive studies examining the biochemical properties of each member of the RuvABC protein complex restricts models in deciphering the functions of the individual components of this tripartite protein complex. Our current understanding of the biochemical function of E. coli RuvA is within the context of its interacting cellular partner, RuvB. Consequently, the inherent activities of RuvA in the context of DNA repair and HR are poorly understood. Moreover, it remains to be ascertained if RuvABC protein complex, its different sub-complexes, or the individual subunits can function differently in the processing of HJ intermediates generated during DNA repair and HR. The information from these studies would be helpful in understanding the mechanistic details of HR pathway in mycobacteria. Additionally, a number of important questions regarding the molecular basis of RuvAB catalyzed fork reversal remain unanswered. Therefore, exploration of biochemical details of the RuvAB mediated RFR would provide mechanistic insights into the dynamics of fork reversal process. Moreover, analysis of RuvAB catalyzed RFR might be helpful in validating the different assumptions of the RFR model that has been proposed on the basis of genetic analysis of certain E. coli replication mutants. Another interesting question that remains to be answered is, how under in vivo conditions, RuvABC protein complex or its individual subunits are regulated to function differently in the context of HR and DNA repair? Mycobacterium tuberculosis is an important intracellular pathogen which is likely to experience substantial DNA damage inside the host and thus may require an efficient DNA recombination and repair machinery for its survival. Our knowledge about the mechanistic aspects of genetic exchange in mycobacteria is rather limited. Therefore, understanding of the processes catalyzed by the components of HR pathway may help in molecular genetic analysis of mycobacteria. Sequence analysis of M. tuberculosis genome, followed by various comparative genomic studies, has revealed the presence of putative homologs of E. coli rec genes but it is not known whether these gene products are able to catalyze the reactions similar to their E. coli counterparts. In M. tuberculosis, the genes encoding for the enzymatic machinery required for branch migration and resolution of HJ intermediates are present. The ruvA, ruvB and ruvC genes form an operon, and are probably translationally coupled. Further, these ruv genes are DNA damage inducible. The transcript level of ruvC is regulated by both RecA dependent and independent mechanisms whereas ruvA and ruvB are induced only through RecA dependent SOS response. During M. tuberculosis infection of host cells, expression of ruvA and ruvB genes is upregulated. We therefore surmise that their gene product might be required for DNA replication, recombination or repair, and would be physiologically relevant under in vivo conditions. However, the details of reactions involved in the processing of HR intermediates and rescue of stalled replication forks in M. tuberculosis remains unknown. In the initial part of this study, we have investigated the function of M. tuberculosis RuvA protein using Holliday junctions containing either homologous or heterologous core. In the later part, we have explored the ability of M. tuberculosis RuvA and RuvB proteins to catalyze in vitro replication fork reversal. M. tuberculosis ruvA gene was isolated by PCR amplification and cloned in an expression vector to generate the pMTRA construct. Genetic complementation assays, using the pMTRA construct transformed into E. coli ΔruvA mutant, indicated that M. tuberculosis ruvA is functional in E. coli and suggested that it can substitute for E. coli RuvA in conferring resistance to MMS and survival following UV irradiation. Having established the functionality of M.tuberculosis ruvA, a method was developed for heterologous over-expression and purification of M. tuberculosis RuvA protein (MtRuvA). MtRuvA was purified to homogeneity and the identity of purified protein was verified using western blot analysis using the anti-MtRuvA antibodies. Purified MtRuvA was free of any contaminating endo- or exo-nuclease activity. Biochemical functions of MtRuvA were defined by performing detailed investigations of DNA-binding and Holliday junction processing activities. Substrate specificity of purified MtRuvA was examined,through DNA binding assays, by using oligonucleotide substrates mimicking differentintermediates involved in the pathway of recombinational DNA repair. Purified M. tuberculosis RuvA exhibited high affinity for HJ substrate but also formed stable complex with replication fork and flap substrate. DNase I footprinting of MtRuvA-homologous Holliday junction complex confirmed that MtRuvA bound at the junction center. The DNase I protection conferred by MtRuvA, on homologous HJ, was two-fold symmetric; the continuous footprint was 10 bp longon one pair of symmetrical arms and 7 bp on the opposite pair of arms. In parallel, DNase footprinting of MtRuvA-heterologous Holliday junction complex generated a footprint that encompassed 16 nucleotide residues on each strand of the Holliday junction. Different crystallographic studies have envisaged an important role for RuvA in base pair rearrangement atthe center of the junction. Also, in crystal structure of tetramer of EcRuvA-HJ complex twobases at the junction center were unpaired. To explore if RuvA binding leads to helical distortionof Holliday junction, MtRuvA-HJ complexes were subjected to chemical probing with KMnO4.In case of heterologous HJ, binding of MtRuvA resulted in appearance of sensitive T residues at the junction crossover. By contrast, binding of MtRuvA to homologous HJ rendered the T residues at the junction center and within the homologous core sensitive to oxidation by KMnO4.Taken together, these observations suggested that binding of MtRuvA distorts two base pairs at the junction crossover in heterologous HJ, whereas in case of homologous HJ base pairs distortion extends into the arms of the junction. These observations with KMnO4 probing were independently validated, in real time, by using sensitive to 2-aminopurine fluorescence spectroscopy measurements of MtRuvA-HJ complexes. To follow structural distortions upon interaction with MtRuvA, HJ variants carrying 2-AP substitution were generated for both homologous and heterologous HJ substrate. In each junction species, the 2-AP residue was uniquely present either at the junction center, adjacent to the center or away from the center. Incase of heterologous HJ, binding of MtRuvA resulted in increase of fluorescence emission of2-AP residues located at the junction crossover but not those of 2-AP residues that were present1-2 base pairs away from the junction center. Binding of MtRuvA to homologous HJ resulted in increase of fluorescence emission of 2-AP residues located at the junction crossover. Further, increase in fluorescence emission was also observed for 2-AP residues present within the homologous core or adjacent to the homologous core in a pair of symmetrically related arms. Thus, 2-AP fluorescence results suggested that binding of MtRuvA to homologous HJ causes base pair distortion within and adjacent to the homologous core whereas in case of heterologous HJ the base pair distortion is restricted to the junction center. Together, these results suggest thatMtRuvA causes two distinct types of base pair distortions between homologous and heterologous HJ substrates. To explore the relationship between binding of MtRuvA and alterations in global structure of the junction DNA, we employed the established technique of comparative gel electrophoresis. Analysis of data from comparative gel electrophoresis revealed that MtRuvA, upon binding to the Holliday junctions, converts the stacked-X structure of HJ to square-planar form and stabilizes the same for loading of RuvB rings and subsequent branch migration by RuvAB complex. Our results underline the possible existence of distinct pathways for RuvA function, which presumably depend on the structure and the nature of the DNA repair or HR intermediates. In summary, our results show that binding of MtRuvA to the HJ induced changes in the local conformation of junction, which might augment RuvB catalyzed branch migration. An unexpected finding is the observation that MtRuvA causes two distinct types of structural distortions, depending on whether the Holliday junction contains homologous or heterologous core. These observations support models wherein RuvA facilitates, in a manner independent of RuvB, base pair rearrangements at the crossover point of both homologous and heterologous Holliday junctions. Although the genetic basis of ruvA ruvB catalyzed RFR in E. coli has been understood in some detail but less is known about the genetic and molecular mechanism of fork reversal in mycobacteria or other organisms. Specifically, to examine if the E. coli paradigm can be generalized to other RuvAB orthologs, we explored the RFR activity of M. tuberculosis RuvAB using a series of oligonucleotides and plasmid-based substrates that mimic stalled replication fork intermediates. This approach might be useful in genetic analysis of factors involved in processing of stalled forks in M. tuberculosis wherein technical difficulties associated with the isolation and characterization of appropriate mutants have limited our understanding of DNA metabolism. Importantly, we have asked the questions as to how the structure at fork junction, extent of reversal and presence of sequence heterology might determine the outcome of RuvAB mediated RFR. The results from this study will be helpful in consolidating the proposed in vivo role for RuvAB complex in fork reversal. The open reading frame corresponding to M. tuberculosis ruvB gene was PCR amplified and cloned in an expression vector to generate the pMTRB construct. Genetic complementation assays were performed to assess the functionality of M. tuberculosis ruvB in E. coli ΔruvB mutant. The data from these assays suggested that M. tuberculosis ruvB is active in E. coli and it is able to make functional contacts with E. coli RuvA. Moreover, the efficient alleviation of MMS toxicity in E. coli ΔruvB mutant suggested that M. tuberculosis ruvB might have a role in relieving replication stress generated under specific in vivo conditions. For biochemical analysis, M. tuberculosis RuvB protein (MtRuvB) was over-expressed in a heterologous system and purified to homogeneity. The identity of purified MtRuvB was verified using western blot analysis using the anti-MtRuvB antibodies. Purified MtRuvB was free of any contaminating endo- or exo- nuclease activity. The DNA-binding properties of MtRuvB were analyzed, in conjunction with its cognate RuvA, by using different substrates that are most likely to occur as intermediates during the processes of DNA replication and/or recombination. MtRuvAB bound HJ, three-way junction and heterologous replication fork with high affinity but with relatively weaker affinity to flap and flayed duplex substrates. MtRuvB displayed very weak affinity for linear duplex and failed to bind linear single-stranded DNA. The high affinity of MtRuvB for HJ substrate, in presence of its cognate RuvA, is indicative of direct and functional interaction between RuvA and RuvB. To further test this idea, the catalytic activity of MtRuvB was assayed in the in vitro HJ branch migration assay. In this assay,MtRuvB, in association with its cognate RuvA, promoted efficient branch migration of homologous HJ over heterologous HJ. To decipher the role of MtRuvAB in processing of stalled replication fork we performed in vitro replication fork reversal (RFR) assay using both oligonucleotide and plasmid based model replication fork substrates. Initially, binding of MtRuvAB to different homologous fork (HomFork) substrates was analyzed using the electrophoretic mobility shift assays. MtRuvAB exhibited similar binding affinity towards different HomFork substrates bearing different spatial orientation of nascent leading and lagging strands. To gain insight into the role of MtRuvAB in processing of replication forks, in vitro RFR reactions were carried out using an array of synthetic homologous fork substrates. In all these reactions, MtRuvAB catalyzed efficient fork reversal leading to generation of both parental duplex and daughter duplex. In the kinetics of fork reversal reaction, for all the fork substrates,the accumulation of daughter duplex increased with time whereas the increase in parental or nascent strand DNA was negligible. Taken together, our results suggest that MtRuvAB can efficiently catalyze in vitro replication fork reversal reaction to generate a Holliday junction intermediate thus implicating that RuvAB mediated fork reversal involves concerted unwinding and annealing of nascent leading and lagging strands. Equally important, we demonstrate the reversal of forks carrying hemi-replicated DNA, thus indicating that MtRuvAB mediated fork reversal is independent of symmetry at the fork junction. For understanding the role of RuvAB mediated processing of stalled forks at chromosome level, the fork reversal assays were performed using plasmid derived model “RF” substrate. Fork reversal was monitored by restriction enzyme digestion mediated release of 5’ end labeled fragments of specific size from the fourth arm extruded at the branch point of fork junction. In these reactions MtRuvAB complex was proficient at generating the reversed arm de novo from the RF substrate. Further, MtRuvAB complex catalyzed extensive fork reversal as analyzed by release of linear duplex of2.9 kb from a JM substrate. Use of non hydrolysable analogs of ATP and analysis of restriction digestion mediated release of duplex fragments from the reversed arm suggested that MtRuvAB catalyzed RFR reaction is ATP hydrolysis dependent progressive and processive reaction. MtRuvAB complex catalyzed fork reversal on plasmid substrate that had been linearized thus indicating that MtRuvAB mediated RFR is uncoupled from DNA supercoils in the substrate. Notably, MtRuvAB promoted reversal of forks in a substrate containing short stretch of heterologous sequences, indicating that sequence heterology failed to impede fork reversal activity of MtRuvAB complex. These results are discussed in the context of recognition and processing of varied types of replication fork structures by RuvAB enzyme complex.