946 resultados para Formação Içá


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The 'human topoisomerase I (htopoI) damage response' was reported to be triggered by various kinds of DNA lesions. Also, a high and persistent level of htopoI cleavage complexes correlated with apoptosis. In the present study, we demonstrate that DNA damage-independent induction of cell death using colcemid and tumor necrosis factor is also accompanied by a strong htopoI response that correlates with the onset of apoptotic hallmarks. Consequently, these results suggest that htopoI cleavage complex formation may be caused by signaling pathways independent of the kind of cellular stress. Thus, protein interactions or signaling cascades induced by DNA damage or cellular stress might lead to the formation of stabilized cleavage complexes rather than the DNA lesion itself. Finally, we show that p53 not only plays a key role in the regulation of the htopoI response to UV-C irradiation but also to treatment with colcemid.

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This paper presents a higher-order beam-column formulation that can capture the geometrically non-linear behaviour of steel framed structures which contain a multiplicity of slender members. Despite advances in computational frame software, analyses of large frames can still be problematic from a numerical standpoint and so the intent of the paper is to fulfil a need for versatile, reliable and efficient non-linear analysis of general steel framed structures with very many members. Following a comprehensive review of numerical frame analysis techniques, a fourth-order element is derived and implemented in an updated Lagrangian formulation, and it is able to predict flexural buckling, snap-through buckling and large displacement post-buckling behaviour of typical structures whose responses have been reported by independent researchers. The solutions are shown to be efficacious in terms of a balance of accuracy and computational expediency. The higher-order element forms a basis for augmenting the geometrically non-linear approach with material non-linearity through the refined plastic hinge methodology described in the companion paper.

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Previous studies have shown that human topoisomerase I cleavage complexes form as a response to various DNA damages in vivo, the so called human topoisomerase I “damage response”. It was suggested that this damage response may play a role in DNA repair as well as in apoptosis, but only very few investigations have been done and the significance of the damage response still remains unclear. Here we demonstrate that human topoisomerase I cleavage complexes induced by high doses of UV irradiation are highly stable for up to 48 h. Furthermore, we show that human topoisomerase I cleavage complexes correlate with apoptosis. However, at low UV doses the cleavage complex level was very low and the complexes were repaired. Surprisingly, we found that high levels of stable cleavage complexes were not only found in UV-irradiated cells but also in untreated cells that underwent apoptosis. A possible role of human topoisomerase I in apoptosis is discussed.

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Aim: To examine if fasting affects serum bilirubin levels in clinical healthy males and females. Methods: We utilised retrospective data from phase 1 clinical trials where blood was collected in either a fed or fasting state at screening and pre-dosing time points and analysed for total bilirubin levels as per standard clinical procedures. Participants were clinically healthy males (n = 105) or females (n = 30) aged 18 to 48 inclusive who participated in a phase 1 clinical trial in 2012 or 2013. Results: We found a statistically significant increase in total serum bilirubin levels in fasting males as compared to non-fasting males. The fasting time correlated positively with increased bilirubin levels. The age of the healthy males did not correlate with their fasting bilirubin level. We found no correlation between fasting and bilirubin levels in clinically normal females. Conclusions: The recruitment and screening of volunteers for a clinical trial is a time-consuming and expensive process. This study clearly demonstrates that testing for serum bilirubin should be conducted on non-fasting male subjects. If fasting is required, then participants should not be excluded from a trial based on an elevated serum bilirubin that is deemed non-clinically significant.

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År 2012 är distribution av litteratur via internet inte längre en framtidsvision, utan ett etablerat format vid sidan av traditionella format som exempelvis pocketboken, den inbundna boken och ljudboken (AAP 2011; Amazon 2011; PaidContent 2011). Men den digitala tekniken etablerar inte enbart ett nytt format, utan förändrar också grundförutsättningarna för litterära konstformer och marknader. Detta kapitel behandlar en betydelsefull aspekt av denna förändring, nämligen hur den digitala tekniken påverkar relationen mellan läsare och författare och ökar läsarens inflytande över den kreativa processen. I den digitala tidsåldern är det möjligt att skapa berättelser online i en interaktiv process som involverar både läsare och författare. Kapitlet presenterar modeller för hur sådan “samproducerad e-litteratur” förändrar marknaden för litteratur och hur den påverkar den traditionella litteraturen.

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Governments are challenged by the need to ensure that ageing populations stay active and engaged as they age. Therefore, it is critical to investigate the role of mobility in older people's engagement in out-of-home activities, and to identify the experiences they have within their communities. This research investigates the use of transportation by older people and its implications for their out-of-home activities within suburban environments. The qualitative, mixed-method approach employs data collection methods which include a daily travel diary (including a questionnaire), Global Positioning System (GPS) tracking and semi-structured interviews with older people living in suburban environments in Brisbane, Australia. Results show that older people are mobile throughout the city, and their car provides them with that opportunity to access desired destinations. This ability to drive allows older people to live independently and to assist others who do not drive, particularly where transport alternatives are not as accessible. The ability to transport goods and other people is a significant advantage of the private car over other transport options. People with no access to private transportation who live in low-density environments are disadvantaged when it comes to participation within the community. Further research is needed to better understand the relationship between transportation and participation within the community environment, to assist policy makers and city and transportation planners to develop strategies for age-friendly environments within the community.

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Located at the intersection of two vulnerable groups in the contemporary labour market, young people who migrate as refugees during adolescence face a unique constellation of opportunities and challenges that shape their employment trajectories. Yet the tendency for research to focus on the early years of refugee settlement means that we have an inadequate understanding the factors that mediate their employment decisions, experiences and outcomes. Based on interviews with 51 young people, this article explores how aspirations, responsibilities, family, education and networks are understood to influence the employment trajectories of adolescent refugee migrants. While this article draws attention to the complex and dynamic range of challenges and constraints that these young people negotiate in the pursuit of satisfying and sustainable employment, what also emerges is an optimistic and determined cohort who, even as they at times unsuccessfully prepare for and navigate the labour market, maintain high hopes for a better life.

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The scientific job market has evolved to a truly globalized market. This is epitomized not only by the English language being the de facto scientific language but also by the increasing share of native language journals that are being offered in multiple languages or have or will fully converted to English (such as, for example, the BISE journal in 2015). Similarly, a plethora of exchange programs exists that allow students and academic staff to visit other institutions and exchange knowledge, ideas, and learning opportunities. While student migration across scientific institutions is an established phenomenon (Gribble, 2008) with ample structures, policies, and schemes such as ERASMUS1 in place, academic staff migration between countries is still a challenge, even if exchange programs exist (Enders, 1998). One reason may be that different career paths, varying teaching loads and different evaluation schemes for what constitutes scientific excellence are notable. This also influences the decision of where to start and continue an academic career. While the university systems themselves have been examined previously (Galliers and Whitley, 2007; Lyytinen et al., 2007) and while there is knowledge about career requirements in different university systems (Dennis et al., 2006; Dean et al., 2011; Loos et al., 2013; Recker, 2013), we still do not know much about individual and contextual decisions of academics that either consider or execute a migration between university systems.

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In this chapter, we discuss four related areas of cryptology, namely, authentication, hashing, message authentication codes (MACs), and digital signatures. These topics represent active and growing research topics in cryptology. Space limitations allow us to concentrate only on the essential aspects of each topic. The bibliography is intended to supplement our survey. We have selected those items which providean overview of the current state of knowledge in the above areas. Authentication deals with the problem of providing assurance to a receiver that a communicated message originates from a particular transmitter, and that the received message has the same content as the transmitted message. A typical authentication scenario occurs in computer networks, where the identity of two communicating entities is established by means of authentication. Hashing is concerned with the problem of providing a relatively short digest–fingerprint of a much longer message or electronic document. A hashing function must satisfy (at least) the critical requirement that the fingerprints of two distinct messages are distinct. Hashing functions have numerous applications in cryptology. They are often used as primitives to construct other cryptographic functions. MACs are symmetric key primitives that provide message integrity against active spoofing by appending a cryptographic checksum to a message that is verifiable only by the intended recipient of the message. Message authentication is one of the most important ways of ensuring the integrity of information that is transferred by electronic means. Digital signatures provide electronic equivalents of handwritten signatures. They preserve the essential features of handwritten signatures and can be used to sign electronic documents. Digital signatures can potentially be used in legal contexts.

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Background. Volitional risky driving behaviours such as drink- and drug-driving (i.e. substance-impaired driving) and speeding contribute to the overrepresentation of young novice drivers in road crash fatalities, and crash risk is greatest during the first year of independent driving in particular. Aims. To explore the: 1) self-reported compliance of drivers with road rules regarding substance-impaired driving and other risky driving behaviours (e.g., speeding, driving while tired), one year after progression from a Learner to a Provisional (intermediate) licence; and 2) interrelationships between substance-impaired driving and other risky driving behaviours (e.g., crashes, offences, and Police avoidance). Methods. Drivers (n = 1,076; 319 males) aged 18-20 years were surveyed regarding their sociodemographics (age, gender) and self-reported driving behaviours including crashes, offences, Police avoidance, and driving intentions. Results. A relatively small proportion of participants reported driving after taking drugs (6.3% of males, 1.3% of females) and drinking alcohol (18.5% of males, 11.8% of females). In comparison, a considerable proportion of participants reported at least occasionally exceeding speed limits (86.7% of novices), and risky behaviours like driving when tired (83.6% of novices). Substance-impaired driving was associated with avoiding Police, speeding, risky driving intentions, and self-reported crashes and offences. Forty-three percent of respondents who drove after taking drugs also reported alcohol-impaired driving. Discussion and Conclusions. Behaviours of concern include drink driving, speeding, novice driving errors such as misjudging the speed of oncoming vehicles, violations of graduated driver licensing passenger restrictions, driving tired, driving faster if in a bad mood, and active punishment avoidance. Given the interrelationships between the risky driving behaviours, a deeper understanding of influential factors is required to inform targeted and general countermeasure implementation and evaluation during this critical driving period. Notwithstanding this, a combination of enforcement, education, and engineering efforts appear necessary to improve the road safety of the young novice driver, and for the drink-driving young novice driver in particular.

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The design activities of the development of the SCRAMSPACE I scramjet-powered free-flight experiment are described in this paper. The objectives of this flight are first described together with the definition of the primary, secondary and tertiary experiments. The Scramjet configuration studied is first discussed together with the rocket motor system selected for this flight. The different flight sequences are then explained, highlighting the SCRAMSPACE I free-flyer separation and re-orientation procedures. A design trade-off study is then described considering vehicle stability, packaging, thermo-structural analysis and trajectory, discussing the alignment of the predicted performance with the mission scientific requirements. The global system architecture and instrumentation of the vehicle are then explained. The conclusions of this design phase are that a vehicle design has been produced which is able to meet the mission scientific goals and the procurement & construction of the vehicle are ongoing.

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The current research extends our knowledge of the main effects of attitude, subjective norm, and perceived control over the individual’s technology adoption. We propose a critical buffering role of social influence on the collectivistic culture in the relationship between attitude, perceived behavioral control, and Information Technology (IT) adoption. Adoption behavior was studied among 132 college students being introduced to a new virtual learning system. While past research mainly treated these three variables as being in parallel relationships, we found a moderating role for subjective norm on technology attitude and perceived control on adoption intent. Implications and limitations for understating the role of social influence in the collectivistic society are discussed.

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Objectives: Concentrations of troponin measured with high sensitivity troponin assays are raised in a number of emergency department (ED) patients; however many are not diagnosed with acute myocardial infarction (AMI). Clinical comparisons between the early use (2 h after presentation) of high sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) assays for the diagnosis of AMI have not been reported. Design and methods: Early (0 h and 2 h) hs-cTnT and hs-cTnI assay results in 1571 ED patients with potential acute coronary syndrome (ACS) without ST elevation on electrocardiograph (ECG) were evaluated. The primary outcome was diagnosis of index MI adjudicated by cardiologists using the local cTnI assay results taken ≥6 h after presentation, ECGs and clinical information. Stored samples were later analysed with hs-cTnT and hs-cTnI assays. Results: The ROC analysis for AMI (204 patients; 13.0%) for hs-cTnT and hs-cTnI after 2 h was 0.95 (95% CI: 0.94–0.97) and 0.98 (95% CI: 0.97–0.99) respectively. The sensitivity, specificity, PLR, and NLR of hs-cTnT and hs-cTnI for AMI after 2 h were 94.1% (95% CI: 90.0–96.6) and 95.6% (95% CI: 91.8–97.7), 79.0% (95% CI: 76.8–81.1) and 92.5% (95% CI: 90.9–93.7), 4.48 (95% CI: 4.02–5.00) and 12.86 (95% CI: 10.51–15.31), and 0.07 (95% CI: 0.04–0.13) and 0.05 (95% CI:0.03–0.09) respectively. Conclusions: Exclusion of AMI 2 h after presentation in emergency patients with possible ACS can be achieved using hs-cTnT or hs-cTnI assays. Significant differences in specificity of these assays are relevant and if using the hs-cTnT assay, further clinical assessment in a larger proportion of patients would be required.

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Trichoderma reesei Rut-C30 is used widely as an expression host for various gene products. We have explored cellular effects caused by the expression of a mutant form of cellobiohydrolase I (CBHI), the major secreted protein of T. reesei using biochemical and transcriptomic analyses and confocal laser scanning microscopy. The mutated CBHI was tagged fluorescently with Venus to establish the subcellular location of the fusion protein and its potential association with the proteasome, an organelle assigned for the disposal of misfolded proteins. Expression of the mutant CBHI in the high protein-secreting host Rut-C30 caused physiological changes in the fungal hyphae, affected protein secretion and elicited ER stress. A massive upregulation of UPR- and ERAD-related genes sec61, der1, uba1, bip1, pdi1, prp1, cxl1 and lhs1 was observed by qRT-PCR in the CBHIΔ4-Venus strain with four mutations introduced in the DNA encoding the core domain of CBHI. Further stress was applied to this strain by inhibiting function of the proteasome with MG132 (N-benzoylcarbonyl(Cbz)-Leu-Leu-leucinal). The effect of MG132 was found to be specific to the proteasome-associated genes. There are no earlier reports on the effect of proteasome inhibition on protein quality control in filamentous fungi. Confocal fluorescence microscopy studies suggested that the mutant CBHI accumulated in the ER and colocalized with the fungal proteasome. These results provide an indication that there is a limit to how far T. reesei Rut-C30, already under secretion stress, can be pressed to produce higher protein yields.