988 resultados para RNA structure logo
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Dissertation presented to obtain the Ph.D degree in Biochemistry, Structural Biochemistry
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Increasingly stringed regulations for diesel engine emissions have a significant impact on the required efficiency of DOC. Lowered DOC oxidation efficiency due to thermal aging effects influences the efficiency of the exhaust aftertreatment systems downstream of the DOC. In this work carried out in the Jean Le Rond d’Alembert Institute the effect of hydrothermal aging on the reactivity and structure of a commercial DOC was investigated. The characterization of the catalytic performance was carried out on a synthetic gas bench using carrots catalyst under conditions close to the realistic conditions i.e. using a synthetic gas mixture, representative of the exhaust gases from diesel engines. Different structural characterization techniques were performed: textural and morphological proprieties were analyzed by BET and TEM, the characterization of the presented crystallographic phases was performed by DRX and the determination of the number of reducible species was possible by TPR. TEM results shown, an increase of the metal particle size with the aging caused by the agglomeration of metal particles, revealing the presence of metal sintering. DRX results also suggest the presence of support sintering. Furthermore, DRX and BET results unexpectedly reveal that the most drastic aging conditions used actually activated the catalyst surface. As expected, the aging affected negatively the catalyst performance on the oxidation of methane and CO, however an improvement of the NO oxidation performance with the aging was observed. Nevertheless, for the aging conditions used, catalytic activity results show that the influence of aging in DOC performance was not significant, and therefore, more drastic aging conditions must be used.
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With the recent advances in technology and miniaturization of devices such as GPS or IMU, Unmanned Aerial Vehicles became a feasible platform for a Remote Sensing applications. The use of UAVs compared to the conventional aerial platforms provides a set of advantages such as higher spatial resolution of the derived products. UAV - based imagery obtained by a user grade cameras introduces a set of problems which have to be solved, e. g. rotational or angular differences or unknown or insufficiently precise IO and EO camera parameters. In this work, UAV - based imagery of RGB and CIR type was processed using two different workflows based on PhotoScan and VisualSfM software solutions resulting in the DSM and orthophoto products. Feature detection and matching parameters influence on the result quality as well as a processing time was examined and the optimal parameter setup was presented. Products of the both workflows were compared in terms of a quality and a spatial accuracy. Both workflows were compared by presenting the processing times and quality of the results. Finally, the obtained products were used in order to demonstrate vegetation classification. Contribution of the IHS transformations was examined with respect to the classification accuracy.
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Grapevine (Vitis vinifera) is one of most agro-economically important fruit crops worldwide, with a special relevance in Portugal where over 300 varieties are used for wine production. Due to global warming, temperature stress is currently a serious issue affecting crop production especially in temperate climates. Mobile genetic elements such as retrotransposons have been shown to be involved in environmental stress induced genetic and epigenetic modifications. In this study, sequences related to Grapevine Retrotransposon 1 (Gret1) were utilized to determine heat induced genomic and transcriptomic modifications in Touriga Nacional, a traditional Portuguese grapevine variety. For this purpose, growing canes were treated to 42 oC for four hours and leaf genomic DNA and RNA was utilized for various techniques to observe possible genomic alterations and variation in transcription levels of coding and non-coding sequences between non-treated plants and treated plants immediately after heat stress (HS-0 h) or after a 24 hour recovery period (HS-24 h). Heat stress was found to induce a significant decrease in Gret1 related sequences in HS-24 h leaves, indicating an effect of heat stress on genomic structure. In order to identify putative heat induced DNA modifications, genome wide approaches such as Amplified Fragment Length Polymorphism were utilized. This resulted in the identification of a polymorphic DNA fragment in HS-0 h and HS-24 h leaves whose sequence mapped to a genomic region flanking a house keeping gene (NADH) that is represented in multiple copies in the Vitis vinifera genome. Heat stress was also found to affect the transcript levels of various non-coding and gene coding sequences. Accordingly, quantitative real time PCR results established that Gret1 related sequences are up regulated immediately after heat stress whereas the level of transcript of genes involved in identification and repair of double strand breaks are significantly down regulated in HS-0 h plants. Taken together, the results of this work demonstrated heat stress affects both genomic integrity and transcription levels.
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INTRODUCTION: Occupational HIV infection among healthcare workers is an important issue in exposures involving blood and body fluids. There are few data in the literature regarding the potential and the duration of infectivity of HIV type 1 (HIV-1) in contaminated material under adverse conditions. METHODS: We quantified HIV-1 viral RNA in 25×8mm calibre hollow-bore needles, after punctures, in 25 HIV-1-infected patients selected during the sample collection. All of the patients selected were between the ages of 18 and 55. Five samples were collected from 16 patients: one sample for the immediate quantification of HIV-1 RNA in the plasma and blood samples from the interior of 4 needles to be analyzed at 0h, 6h, 24h, and 72h after collection. In nine patients, another test was carried out in the blood from one additional needle, in which HIV-1 RNA was assessed 168h after blood collection. The method used to assess HIV-1 RNA was nucleic acid sequence-based amplification. RESULTS: Up to 7 days after collection, HIV-1 RNA was detected in all of the needles. The viral RNA remained stable up to 168h, and there were no statistically significant differences among the needle samples. CONCLUSIONS: Although the infectivity of the viral material in the needles is unknown, the data indicate the need to re-evaluate the practices in cases of occupational accidents in which the source is not identified.
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Currently, Portugal assumes itself as a democratic rule of substantive law State, sustained by a legal system seeking the right balance between the guarantee of fundamental rights and freedoms constitutional foreseen in Portugal’s Fundamental Law and criminal persecution. The architecture of the penal code lies with, roughly speaking, a accusatory basic structure, “deliberately attached to one of the most remarkable achievements of the civilizational democratic progress, and by obedience to the constitutional commandment”, in balance with the official investigation principle, valid both for the purpose of prosecution and trial. Regarding the principle of non self-incrimination - nemo tenetur se ipsum accusare, briefly defined as the defendant’s right of not being obliged to contribute to the self-incrimination, it should be stressed that there isn’t an explicit consecration in the Portuguese Constitution, being commonly accepted in an implicit constitutional prediction and deriving from other constitutional rights and principles, first and foremost, the meaning and scope of the concept of democratic rule of Law State, embedded in the Fundamental Law, and in the guidelines of the constitutional principles of human person dignity, freedom of action and the presumption of innocence. In any case, about the (in) applicability of the principle of the prohibition of self-incrimination to the Criminal Police Bodies in the trial hearing in Court, and sharing an idea of Guedes Valente, the truth is that the exercise of criminal action must tread a transparent path and non-compliant with methods to obtain evidence that violate the law, the public order or in violation of democratic principles and loyalty (Guedes Valente, 2013, p. 484). Within the framework of the penal process relating to the trial, which is assumed as the true phase of the process, the witness represents a relevant figure for the administration of criminal justice, for the testimonial proof is, in the idea of Othmar Jauernig, the worst proof of evidence, but also being the most frequent (Jauernig, 1998, p. 289). As coadjutant of the Public Prosecutor and, in specific cases, the investigating judge, the Criminal Police Bodies are invested with high responsibility, being "the arms and eyes of Judicial Authorities in pursuing the criminal investigation..." which has as ultimate goal the fulfillment of the Law pursuing the defense of society" (Guedes Valente, 2013, p. 485). It is in this context and as a witness that, throughout operational career, the Criminal Police Bodies are required to be at the trial hearing and clarify the Court with its view about the facts relating to occurrences of criminal context, thus contributing very significantly and, in some cases, decisively for the proper administration of the portuguese criminal justice. With regards to the intervention of Criminal Police Bodies in the trial hearing in Court, it’s important that they pay attention to a set of standards concerning the preparation of the testimony, the very provision of the testimony and, also, to its conclusion. Be emphasized that these guidelines may become crucial for the quality of the police testimony at the trial hearing, thus leading to an improvement of the enforcement of justice system. In this vein, while preparing the testimony, the Criminal Police Bodies must present itself in court with proper clothing, to read before and carefully the case files, to debate the facts being judged with other Criminal Police Bodies and prepare potential questions. Later, while giving his testimony during the trial, the Criminal Police Bodies must, summing up, to take the oath in a convincing manner, to feel comfortable, to start well by convincingly answering the first question, keep an attitude of serenity, to adopt an attitude of collaboration, to avoid the reading of documents, to demonstrate deference and seriousness before the judicial operators, to use simple and objective language, to adopt a fluent speech, to use nonverbal language correctly, to avoid spontaneity responding only to what is asked, to report only the truth, to avoid hesitations and contradictions, to be impartial and to maintain eye contact with the judge. Finally, at the conclusion of the testimony, the Criminal Police Bodies should rise in a smooth manner, avoiding to show relief, resentment or satisfaction, leaving a credible and professional image and, without much formality, requesting the judge permission to leave the courtroom. As final note, it’s important to stress that "The intervention of the Police Criminal Bodies in the trial hearing in Court” encloses itself on a theme of crucial importance not only for members of the Police and Security Forces, who must welcome this subject with the utmost seriousness and professionalism, but also for the proper administration of the criminal justice system in Portugal.
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A Work Project, presented as part of the requirements for the Award of a Master’s Double Degree in Finance from Maastricht University and NOVA – School of Business and Economics
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Bradykinin is a peptide of the kinin group, involved in a number of receptor-mediated physiological actions, including inflammation and vasodilation, as well as neuromodulation, neuroprotection and promotion of neurogenesis. Bradykinin is the main ligand of the B2 receptor- the main kinin receptor- which is involved in the cardiac and renal protective effects of kinins in diseases. Antibodies have been considered for a long time as promising therapeutic agents in various fields, especially cancer-related ones. Aptamers, on the other hand, have proven to be an excellent alterative, since they have similar properties to those of monoclonal antibodies, such a high-specificity of recognition and high-affinity binding. Plus, they are developed using in vitro selection procedures and can be reproduced by enzymatic reactions. SELEX is a powerful tool for the development of both DNA and RNA aptamers. The main goal of this project was to design a method to select aptamers against bradykinin using capillary electrophoresis alongside the SELEX technique. The selection was done by comparing the aptamers’ (ssDNA-target complex) electrophoretic mobility with that of the ssDNA and the target, which allowed us to define an appropriate collection window that took into consideration the analytes’ detection time, thus enabling the collection of the desired oligonucleotides. After two selection rounds, the collected pool was sequenced, the affinity was measured and the aptamers’ secondary structure was predicted. We concluded that with only two selection cycles, the original DNA library’s bulk affinity grew around 0.4%. The structural characterization of the aptamers, performed with the aid of the Mfold software, revealed that there are many repetitive motifs amongst them, indicating that the selection process was successful. We have obtained 16 sequences of candidate aptamers as bradykinin ligands of similar sequences and secondary structures whose biological activity should be analyzed after synthesis; mainly in regard to their role as bradykinin inhibitors.
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Introduction: Hepatitis C virus (HCV) infection is diagnosed by the presence of antibodies and is supplemented by confirmatory testing methods, such as recombinant immunoblot assay (RIBA) and HCV-RNA detection. This study aimed to evaluate the efficacy of RIBA testing to diagnose HCV infection in blood donors positive for anti-HCV antibodies. Methods: A total of 102 subjects positive for anti-HCV determined by enzyme-linked immunosorbent assay (ELISA) at the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) were later assessed with new samples using the Abbott Architect anti-HCV test (Abbott Diagnostics, Wiesbaden, Germany), the RIBA III test (Chiron RIBA HCV 3.0 SIA, Chiron Corp., Emeryville, CA, USA), the polymerase chain reaction (PCR; COBAS® AMPLICOR HCV Roche Diagnostics Corp., Indianapolis, IN, USA) and line probe assay (LiPA - Siemens, Tarrytown, NY, USA) genotyping for HCV diagnosis. Results: Of these new samples, 38.2% (39/102) were positive, 57.8% (59/102) were negative and 3.9% (4/102) were indeterminate for anti-HCV; HCV-RNA was detected in 22.5% (23/102) of the samples. RIBA results were positive in 58.1% (25/43), negative in 9.3% (4/43) and indeterminate in 32.6% (14/43) of the samples. The prevailing genotypes were 1 (78.3%, 18/23), 3 (17.4%, 4/23) and 2 (4.3%, 1/23). All 14 samples with indeterminate RIBA results had undetectable viral loads (detection limit ≤50 IU/mL). Of these samples, 71.4% (10/14) were reevaluated six months later. Eighty percent (8/10) of these samples remained indeterminate by RIBA, and 20% (2/10) were negative. Conclusions: In this study, individuals with indeterminate RIBA results had no detectable HCV-RNA.
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The main objective of this thesis was the development of polymeric structures from the dissolution of FucoPol, a bacterial exopolysaccharide (EPS), in a biocompatible ionic liquid, choline acetate. The FucoPol was produced by the bacteria Enterobacter A47 using glycerol as carbon source at controlled temperature and pH (30ºC and 7, respectively). At the end of 3 days it was produced 7 g/L of FucoPol. The net yield of Fucopol in glycerol (YP/S) was 0.22 g/g and the maximum productivity 2.37 g/L.d This polymer was characterized about its composition in sugars and acyl groups (by High-Performance Liquid Chromatography - HPLC), containing fucose (35 % mol), galactose (21 % mol), glucose (29 % mol), rhamnose (3% mol) and glucuronic acid (12% mol) as well as acetate (14.28 % mol), pyruvate (2.15 % mol) and succinate (1.80 % mol). Its content of water and ash was 15% p/p and 2% p/p, respectively, and the chemical bonds (determined by Infrared Spectroscopy - FT-IR) are consistent to the literature reports. However, due to limitations in Differential Scanning Calorimetry (DSC) equipment it was not possible to determine the glass transition temperature. In turn, the ionic liquid showed the typical behavior of a Newtonian fluid, glass transition temperature (determined by DSC) -98.03ºC and density 1.1031 g/cm3. The study of chemical bonds by FT-IR showed that amount of water (8.80%) influenced the visualization of the bands predicted to in view of their chemical structure. After the dissolution of the FucoPol in the ionic liquid at different temperatures (50, 60, 80 and 100 ° C) it was promoted the removal of this by the phase inversion method using deionized water as a solvent, followed by drying in an oven at 70 ° C. The mixtures before and after the phase inversion method were characterized through the studies mentioned above. In order to explore possible application field’s biocompatibility assays and collage on balsa wood tests were performed. It was found that the process of washing with water by the phase inversion method was not totally effective in removing the biocompatible ionic liquid, since all FucoPol – IL mixtures still contained ionic liquid in their composition as can be seen by the DSC results and FT-IR. In addition, washing the mixtures with water significantly altered the composition of FucoPol. However, these mixtures, that developed a viscous behavior typical of a non-Newtonian fluid (shear-thinning), have the potential to be applied in the biomedical field as well as biological glues.
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Management
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O objectivo desta dissertação é identificar a estrutura da percepção tal como ela é desenhada por Hiérocles nos <,(#= >1!(?$%&'(). Para alcançar este objectivo focar-me-ei na análise que o filósofo estóico leva a cabo em torno da percepção. O foco começa por incindir sobre a distinção entre percepção de si e percepção do exterior, com todas as suas subtilezas. Tal análise implicará então a consideração da importância da não-indiferença nessa estrutura de percepção. O objectivo é compreender como a percepção é sempre relacional e interessada. . Centrar-me-ei então na noção de !"#$%&'(), tentanto explorar a complexidade e multiplicidade do fenómeno em causa. Será também estabalecida a relação com o fragmento de Estobeu (6.671), que é, a par da obra, a fonte mais importante do pensamento de Hiérocles. Através desta relação introduzir-se-á a estrutura circular e concêntrica de uma percepção relacional e interessada. Toda esta dissertação será levada a cabo focando-se principalmente nos textos do próprio Hiérocles.
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In 2007, the UK government commissioned the Energy Demand Research Project to conduct a large scale experiment of smart metering technologies to test the impacts from many different forms of feedback to residential consumers. A full evaluation of the results was completed in 2011. In Portugal, EDP is also conducting smart meter trials in a project called InovCity in the city of Évora whose results will be evaluated during 2012. In this work, the case of Great Britain is studied as a reference on how an evaluation of trial results should be conducted. I also discuss potential limitations of the experiments, implications for national roll-out decisions, and finally draw some lessons that can be applied to the Portuguese case.
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Large chromosomal rearrangements are common in natural populations and thought to be involved in speciation events. In this project, we used experimental evolution to determine how the speed of evolution and the type of accumulated mutations depend on the ancestral chromosomal structure and genotype. We utilized two Wild Type strains and a set of genetically engineered Schizosaccharomyces pombe strains, different solely in the presence of a certain type of chromosomal variant (inversions or translocations), along with respective controls. Previous research has shown that these chromosomal variants have different fitness levels in several environments, probably due to changes in the gene expression along the genome. These strains were propagated in the laboratory at very low population sizes, in which we expect natural selection to be less efficient at purging deleterious mutations. We then measured these strains’ changes in fitness throughout this accumulation of deleterious mutations, comparing the evolutionary trajectories in the different rearrangements to understand if the chromosomal structure affected the speed of evolution. We also tested these mutations for possible epistatic effects and estimated their parameters: the number of arising deleterious mutations per generation (Ud) and each one’s mean effect (sd).