48 resultados para liga NiZn
Resumo:
Steel is an alloy EUROFER promising for use in nuclear reactors, or in applications where the material is subjected to temperatures up to 550 ° C due to their lower creep resistance under. One way to increase this property, so that the steel work at higher temperatures it is necessary to prevent sliding of its grain boundaries. Factors that influence this slip contours are the morphology of the grains, the angle and speed of the grain boundaries. This speed can be decreased in the presence of a dispersed phase in the material, provided it is fine and homogeneously distributed. In this context, this paper presents the development of a new material metal matrix composite (MMC) which has as starting materials as stainless steel EUROFER 97, and two different kinds of tantalum carbide - TaC, one with average crystallite sizes 13.78 nm synthesized in UFRN and another with 40.66 nm supplied by Aldrich. In order to improve the mechanical properties of metal matrix was added by powder metallurgy, nano-sized particles of the two types of TaC. This paper discusses the effect of dispersion of carbides in the microstructure of sintered parts. Pure steel powders with the addition of 3% TaC UFRN and 3% TaC commercial respectively, were ground in grinding times following: a) 5 hours in the planetary mill for all post b) 8 hours of grinding in the mill Planetary only for steel TaC powders of commercial and c) 24 hours in the conventional ball mill mixing the pure steel milled for 5 hours in the planetary mill with 3% TaC commercial. Each of the resulting particulate samples were cold compacted under a uniaxial pressure of 600MPa, on a cylindrical matrix of 5 mm diameter. Subsequently, the compressed were sintered in a vacuum furnace at temperatures of 1150 to 1250 ° C with an increment of 20 ° C and 10 ° C per minute and maintained at these isotherms for 30, 60 and 120 minutes and cooled to room temperature. The distribution, size and dispersion of steel and composite particles were determined by x-ray diffraction, scanning electron microscopy followed by chemical analysis (EDS). The structures of the sintered bodies were observed by optical microscopy and scanning electron accompanied by EDS beyond the x-ray diffraction. Initial studies sintering the obtained steel EUROFER 97 a positive reply in relation to improvement of the mechanical properties independent of the processing, because it is obtained with sintered microhardness values close to and even greater than 100% of the value obtained for the HV 333.2 pure steel as received in the form of a bar
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Metal-Ceramic (M/C) Zirconia-stainless steel interfaces have been processed through brazing techniques due to the excellent combination of properties such as high temperature stability, high corrosion resistance and good mechanical properties. However, some M/C interfaces show some defects, like porosity and cracks results in the degradation of the interfaces, leading even to its total rupture. Most of time, those defects are associated with an improper brazing parameters selection to the M/C system. In this work, ZrO2 Y-TZP and ZrO2 Mg - PSZ were joint with the stainless steel grade 304 by brazing using a eutectic silver-copper (Ag28Cu) interlayer alloy with different thermal cycles. Ceramic surfaces were previous mechanically metallized with titanium to improve adhesion of the system. The effect of temperature on the M/C interface was studied. SEM-EDS and 3 point flexural bend test were performed to evaluate morphology, chemical composition and mechanical resistance of the M/C interfaces. Lower thermal cycle temperatures produced better results of mechanical resistance, and more regular/ homogeneous reaction layers between braze alloy and metal-ceramic surfaces. Also was proved the AgCu braze alloy activation in situ by titanium
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The resistance of aluminum and their alloys, to the corrosion phenomenon, in aqueous solutions, is a result of the oxide layer formed. However, the corrosion process in the aluminum alloy is associated with the presence a second phase of particles or the presence of chloride ions which promote the disruption of the oxide layer located producing the corrosion process. On the other hand, the term water produced is used to describe the water after the separation of the oil and gas in API separators. The volumes of produced water arrive around 5 more times to the volume of oil produced. The greatest feature of the water is the presence of numerous pollutants. Due to the increased volume of waste around the world in the current decade, the outcome and the effect of the discharge of produced water on the environment has recently become an important issue of environmental concern where numerous treatments are aimed at reducing these contaminants before disposal. Then, this study aims to investigate the electrochemical corrosion behavior of aluminum alloy 6060 in presence of water produced and the influence of organic components as well as chloride ions, by using the electrochemical techniques of linear polarization. The modification of the passive layer and the likely breakpoints were observed by atomic force microscopy (AFM). In the pit formation potential around -0.4 to -0.8 V/EAg/AgCl was observed that the diffusion of chloride ions occurs via the layer formed with the probable formation of pits. Whereas, at temperatures above 65 °C, it was observed that the range of potential for thepit formation was -0.4 to -0.5 V/EAg/AgCl. In all reactions, the concentration of Al(OH)3 in the form of a gel was observed
Resumo:
Riboflavin is a vitamin very important in aerobic organisms, as a precursor of many coenzymes involved in the electron transporter chain. However, after photosensitization of riboflavin with UV or visible light, it generates reactive oxygen species (ROS), which can oxidize the DNA. The repair of oxidative lesions on DNA occurs through the base excision repair pathway (BER), where APE1 endonuclease plays a central role. On the other hand, the nucleotide excision repair pathway (NER) repairs helix-distorting lesions. Recently, it was described the participation of NERproteins in the repair of oxidative damage and in stimulation of repair function fromAPE1. The aim of this research was to evaluate the cytotoxic effects of photosensitized riboflavin (RF*) in cells proficient and deficient in NER, correlating with APE1 expression. For this propose, the cells were treated with RF* and it was performed the cell viability assay, extraction of whole proteins, cells fractionation, immunoblotting, indirect immunofluorescence and analysis of polymorphisms of BER gens. The results evidenced that cells deficient in XPA and CSB proteins were more sensitive to RF*. However, XPC-deficient cells presented similar resistance to MRC5- SV cells, which is proficient in NER. These results indicate that XPA and CSB proteins have an important role on repair of oxidative lesions induced by RF*. Additionally, it was evidenced that single nucleotide polymorphisms (SNPs) in BER enzymes may influence in sensitivity of NER-deficient cell lines. Concerning the APE1 expression, the results showed that expression of this protein after treatment with RF* only changed in XPC-deficient cells. Though, it was observed that APE1 is recruited and is bound to chromatin in MRC5-SV and XPA cells after treatment with RF*. The results also showed the induction of DNA damage after treatment with RF*, through the analysis of-H2AX, since the treatment promoted an increase of endogenous levels of this phosphorylated protein, which acts signaling double strand-break on DNA. On the other hand, in XPC-deficient cells, regardless of resistance of RF*, the endogenous levels of APE1 are extremely reduced when compared with other cell lines and APE1 is not bound to chromatin after treatment with RF*. These results conclude that RF* was able to induce cell death in NERdeficient cells, where XPA and CSB cells were more sensitive when compared with MRC5-SV and XPC-deficient cells. This last result is potentially very interesting, since XPC-deficient cell line presents low levels of APE1. Additionally, the results evidenced that APE1 protein can be involved in the repair of oxidative damage induced by RF*, because APE1 is recruited and bound strongly to chromatin after treatment.
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A esplenectomia é indicada em doenças hematológicas, hiperesplenismo grave, traumas e tem sido causa de importantes alterações metabólicas e imunológicas. O objetivo do presente trabalho é avaliar se a retirada do baço altera a biodistribuição do radiofármaco DMSA Tc99m em ratos Wistar e se há correlação com possíveis alterações da função renal. Foram usados dois grupos: esplenectomia (n=6) e controle (n=6) animais não operados. Após 15 dias, foi administrado 0,1 ml de DMSA-Tc99m via plexo orbital (0,66 MBq). Trinta minutos depois, foram retiradas amostras do rim, coração, pulmão, tireóide, estômago, bexiga, fêmur, sangue. Após pesadas as amostras, foi determinado o percentual de radioatividade/g (% ATI/g) em cada uma delas, com o Wizard Gama Counter Perkin-Elmer . Dosadas uréia e creatinina sérica, hematócrito, plaquetas e leucócitos. Estatística pelo teste t, com significância 0,05. Foi observada redução significante no %ATI/g no rim e sangue (p<0,05) dos animais esplenectomizados, aumento significante (p<0,05) da uréia (88,8±18,6mg/dL) e creatinina (0,56±0,08), comparado aos controles (51,5±1,6 e 0,37±0,02mg/dL, respectivamente) assim como leucocitose, aumento de plaquetas e redução de hematócrito. Em conclusão, a esplenectomia provocou comprometimento da função renal, repercutindo na alteração da captação de DMSA 99mTc pelo rim de ratos. Uma parceria entre a Unidade de Medicina Nuclear da Liga Norteriograndense Contra o Câncer e o Núcleo de Cirurgia Experimental da Universidade Federal do Rio Grande doNorte tornou possível a realização deste trabalho, que contou com a participação de profissionais de diferentes áreas como: Biologia, Biomedicina, Medicina Nuclear, Cirurgia Geral, Bioquímica e Estatística, atestando dessa forma o caráter multidisciplinar do trabalho
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Fucana é um termo que define uma família de hetero e homopolissacarídeos que contem L-fucose em sua estrutura. Neste trabalho uma hererofucan F 2,0v da alga Dictyota menstrualis foi avaliada como agente antinociceptivo e antiinflamatório. A fucana F 2,0v inibiu a migração de leucócitos em até 100% (20.0 mg/kg) para a cavidade peritoneal após estimulo químico, porém, não alterou a expressão das interleucinas IL-1β, IL-6 e de TNF-α. Com relação a sensação dolorosa a F 2,0v (20.0 mg/kg) possui atividade antinociceptiva periférica com potência semelhante à dipirona. Por outro lado não apresentou efeito no teste da placa quente. Análises de microscopia confocal e citometria de fluxo mostram que a F 2,0v se liga a superfície dos leucócitos. O conjunto de resultados apresentados pela fucana F 2,0v sugerem que o mecanismo de ação está relacionado com sua capacidade de inibir a migração de leucócitos para o local da injúria tecidual. Em resumo os dados mostram que F 2,0v apresenta grande potencial como composto antinociceptivo e antiinflamatório. Estudos futuros serão realizados para caracterizar melhor o mecanismo de ação da F 2,0v
Resumo:
The biliopancretic diversion with duodenal switch is one of the mixing techniques used in the treatment of morbid obesity. The duodenal switch reduces the stomach capacity and leaves only 50-100 cm of small intestine for nutrition and absorption. The surgery produces hormonal, structural and biochemical changes, which can influence on the result of scintigraphic examinations in operated patients. With the objective of evaluate the postoperative biodistribution of sodium pertechnetate (Na99mTcO4) in brain, thyroid, heart, lung, liver, spleen, kidney, stomach, duodenum, pancreas, small intestine, bladder, muscle and bone of Wistar rats. The rats were randomly allocated into 3 groups of 7 rats each: the duodenal switch group (DS), the control group (C) and the sham group (S). They were operated under anesthesia and aseptic technique. In the tenth postoperative day, 0.1mL of sodium pertechnetate was injected via orbital plexus. After 30 min the animals were killed with overdose of anesthetic and samples of liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, bone and brain were harvested, washed with saline and weighed. The detention of radioactivity was made using the automatic Gamma Counter Wizard, PerkinElmer and the percentage of activity per gram of tissue (%ATI/g) was calculated. There was no early or late mortality in either rats groups. The values of percent radioactivity per gram of tissue (%ATI/g), showed no significant difference in liver, stomach, small bowel, duodenum, kidney, heart, bladder, bone and brain, when compared the DS rats with sham and controls rats. A postoperative significant increase in mean %ATI/g levels was observed in spleen, pancreas and muscle in group DS rats, as compared to group S and C rats (p<0.05). In the lung there was an increase and in thyroid a decrease in mean %ATI/g of DS rats, when compared to sham rats (p>0.05). In conclusion, the biliopancreatic diversion with duodenal switch in rats modified the biodistribution of sodium pertechnetate in thyroid, lung, pancreas, spleen and muscle. The study had the participation of the departments and laboratories researches, as Nucleus of Experimental Surgery, Department of Surgery, Laboratory of Radiobiology, Department of Pathology and Service of Nuclear Medicine, certifying the character of a multidisciplinary research
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It historizes and it analyzes the social capital in the area Seridó. The traditions associative seridoenses are reconstructed starting from the dimensions: economical, social, religious person and politics. In them it is possible to notice actions that form the social capital of the area. The country of Seridó present an associative tradition based on the mutual help, in the trust and reciprocity that she remount there are decades in your history. The relationship among the Catholic Church, that historically it is present in the area, and rural communities, through your community associations, it is the backdrop where you/they are the responsible associative elements for the tear of the regional social fabric: in him (the backdrop) he/she is the responsible social capital for the work of the rural community organizations. The Catholic Church, through your social action and the Program of Combat to the Rural Poverty, of Rio Grande do Norte is the league that sustains the actions collective seridoenses
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Shows up the memory of the elderly, as a consistent experience in the in the construction of the social memory of Janduís, Rio Grande do Norte, where the research takes place. Through an autobiographic narrative, in a qualitative approaching, the intent is to stand up aspects about the individual history and collective memories, starting in a simple question: what did they remember? A question that turns into many others, as how the remember and under which circumstances. So, the lived and remembered moments are the subject of this paper, as these testimonials shows and reveals the citizens typical aspects, intending to telling (again) the city s history by the memories of this people. By oral statements and the analysis that followed, subjective aspects that made a social memory, highlight in violent episodes, that, now remembered, occurred in the historical sediment, which connects several social times, establishing a narrative standard. In Janduís, this standard is about the memory that sticks out their individual ways, and the collective life, in the past, standing out the fair and the events that occurred on it, as the most remembered place, where the memories go stronger. When they narrate are incorporated others facts, the story is reinvented, connecting the past to the future. The paper also revels builders subjects aspects of a social memory, as historical sediment that joins the social times. At the present moment, the fair, to them, is a place that doesn t exist anymore; for the city, is a place of enlargement of women s presence at the trending spaces, which means a place of social transformation. That being said, the fair, in both times, present and past, turns into a analysis object, with important elements to reference narrative s time and place. And how the narrative update the past recorded in the old citizen s memory. What was intended to do was articulate the memory and the history form temporal and special etching that define the place and the narrative context: the lived and the remembered at the group s day by day. In that way, were identify the collective memory s common elements, enunciating the memory and the narratives that update that history, influencing and being influenced, forming in memories in a collective phenomenon fueling the local imaginary
Resumo:
The purpose of this study is to understand what are the matrix elements in which everyday activities of social author/authors, actor/actors and actress/actresses are embedded, in order to carry out the Escola da Ponte s political and pedagogic process (PPP). Thus, the object of this study is to reflect on an experience developed in a public school supported by the Portuguese State within the scenario of institutions that are committed to building up a school of the people by investing in democratization and community participation in their management process. The methodological course of action was targeted at the presuppositions of qualitative research (WOODS, 1999; BURGESS, 1997; MILLS, 1982; OLIVEIRA, 1998; BOGDAN and BIKLEN, 1994; MACEDO, 2000; CASAL, 1996; GEERTZ, 2000), with data collected from random word association (MACHADO and CARVALHO, 2003), the discourse of the interviewed (KAUFMANN, 1996; SILVA, 2006; 2002), observation notes and documents (ELIAS, 1997). Based on a multiple reference and theoretical framework, the investigation revealed elements that are construed as the raw material and pillars supporting the bridge of a school of the people, as well as the self-organization of the school community which emerges as a dimension that binds together all the elements and brings new arrangements into the school dynamics by moving from the individual to the society (DUPUY, 1990). Along this line, the central argument is that in the short and long run the public school quality does not spring from macro educational policies, nor from ephemeral mass-production programs, projects or governmental policies, but from the intent of the professionals working there in becoming authors and characters in the process of building up and carrying out the PPP. The Project has been conceived in the light of the needs and intentionality of the community whose support comes from the participation and social control held by the students families and the community s power to force to action public administration central agencies aiming at having the State fulfill its responsibilities
Resumo:
The Hospital Epidemiology Nucleus (NHE) is a structure that has a specific organizational climate, which influence the level of job satisfaction among professionals working in it. This is a descriptive study with a quantitative approach, aimed to identify the relationship between organizational climate in the NHE regulated in the city of Natal / RN and the job satisfaction among its professionals from the perspective of theoretical issues about Organizational Development. The research was carried out in 13 hospitals with different kinds of sponsorship, 9 public, 3 philanthropic and 1 private. Data were collected using the instrument "organization in hospitals: issues relating to climate and job satisfaction , with 33 professionals appointed and active on NHE. This study obtained an appropriate consent of the Research Ethics Committee of the Hospital of Pediatrics Professor Heriberto Ferreira Bezerra, from the Riograndense Northern League Against Cancer and the Federal University of Rio Grande do Norte. Data collected were organized and treated with simple descriptive statistics. It was observed that from 33 of surveyed people, 93% was female, had an average of 40 years old age, with activity duration between 1 and 2 years (84.9%). Furthermore, 45.5% of industry professionals were nurses. It was identified that professionals working in NHE perceive and experience its work environment as an Organization Structure in construction. It was found that with the exception of the aspects "working life", "socio-cultural" and "organizational culture , the other internal and external factors to the NHE does not have strong expression in the forming of an organizational climate conducive to the development of the sector. It was found that 70% of interviewed perceive the organizational climate as favorable for the industry's progress. Regarding the job level of satisfaction, respondents feel fairly satisfied with the organizational structure. Therefore, the results of this study are suggestive that there is some factor that is greatly contributing to a healthy organizational climate that encourages the industry team members of the NHE present behaviors that identify them as actors committed and satisfied with the work, even face of all obstacles to implementation of epidemiological surveillance. Thus, it is suggested for futures studies to seek to determine how the organizational culture, while significant internal factor, influencing the organizational climate establishment of NHE and therefore the level of job satisfaction and well-being of each members of the team
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In recent years, the biosafety has been made possible a new look which are based the conceptions of health and illness process, as well as human needs. This new vision is focused on health vigilance that is referenced specifically in this study to the worker s health. The health of workers is essential for the prevention and control of epidemics and outbreaks of diseases as well as emerging and reemerging diseases. The present study wants to show the importance of biosafety measures for health workers, showing them through the concepts in their daily work. It is also to direct the use of biosafety measures in the care of oncology and hematology patients care, because of its infection susceptibility. OBJECTIVES: To analyze the conceptions of health workers in the biosafety pratice to the patients in oncological and hematological treatment in an oncological institution in Natal / RN, as well as make a socio-demographic profile of these workers and to know their difficulties to adequate biosafety measures. METODOLOGIA: The research is exploratory descriptive with qualitative approach, using the technique of oral history. The use of this technique is justified for the possibility of analyze the conceptions of health workers in the face of biosafety measures. From the definition of analysis categories that have emerged in the study. The categories were: daily work, education, occupational risk and onco-hematological care. The research population was the health workers who provide care to patients in oncological and hematological treatment. The study was conducted in the League against Cancer, in Natal / RN, specifically in the unit Luiz Antonio Hospital. Data collections were conducted from June to August of 2011 and were interviewed sixteen employees who assist in oncology and hematology. Structured interviews were conducted in three shifts, given the prospects of expanding the possibilities of analysis of the biosafety concepts. After data collection, the interviews were analyzed qualitatively by the technique of oral history. This genre, thematic oral history is a modern resource used for preparation of documents, files and studies concerning the social experience of people and groups with the construction of a script prior to the interview moment (MEIHY, 2002). ANALYSIS OF INFORMATION: It was made a reflection about the concepts and practices of professionals who take care of patients in oncology and hematology as well as its relation to biosafety measures. The speech of employees revealed that the adoption has been very supportive of these standards, although some have been highlighted gaps in the understanding of employees in relation to biosafety and the proposed categories. CONCLUSION: The analysis of information showed that biosafety has been cited by employees as an immeasurable benefit to safety and occupational health. And the strengths marks in their understanding were: the excellence of care and safety in occupational diseases risk reduction and infections resulting from their work activities, despite some difficulties in adopting appropriate biosafety standards
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The studies paths in the maze: life story of individuals with oncological diseases into use of blood transfusion in Natal has the hemotherapy as a primordial procedure to review the relationship between users of oncological health and the due ramifications. The hemotherapy looks for supply the organic needs through blood transfusion, which acquires vital function to the ones that have cancer, because it might reestablish the functionality of the organism throughout the raising of blood components. The impact over the transfusion affects emotionally and physically the users life. Aiming to reflect on these impacts, this study tried, through narratives of lives, rescue their experience since their knowledge of the disease until the time of blood transfusion using. It s about an exploratory-descriptive study, where the qualitative approach uses the theoretical-methodological reference of the oral life history to analyze a colony consisting of five users of health diagnosed with cancer, with achievement of at least three blood transfusions, the clinic Núcleo de Hematologia e Hemoterapia - UFRN, in Natal-RN. The network, in turn, was composed by employees of both sexes, regardless of age, who voluntarily agreed to participate in the study. The data collection, with approval of the Ethics Committee in Research, Liga Norte Riograndense Contra o Cancer, on the number 001/001/2012, occurred through semi-structured interviews, recorded individually in the home context that was previously chosen by employees. The methodological procedure occurred with the transcription of the interviews and their transcreations, and analysis of reports by thematic content analysis. At the reading orientation and interpretation of the employees stories, were discussed three categories of analysis: the impact on psychological REVIEW; impact on socialization and group membership, the environment and the impact of blood transfusion on treatment. Based on the narrative of the life histories of employees, we conclude that the experiences and feelings, hope and sorrow, pain and faith, even when facing a disease like cancer, bring lots of teaching and learning to health professional that deposits humanization health and reinstate hemotherapy forms of clinical critical
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Several epidemics marked the lives of individuals and communities in all historical periods, and a prime example is leprosy, infectious disease marked by stigma, prejudice and social exclusion. In the past, the compulsory isolation of patients with leprosy caused serious social and psychological problems, resulting in the separation and the partial or total disruption of the family relationship. Children deprived of this living, removed often inhumanely, were kept and bred in preventoriums / educational establishments. This study aimed to: rescue the oral history of life of the children of leprosy patients that were built in preventorium Osvaldo Cruz, Natal, Rio Grande do Norte; develop a contextual analysis about these children; know the life trajectory of children of leprosy patients institutionalized in preventoriums / educational establishments; produce a documentary on the history of life of children of parents separated by leprosy; forming MORHAN of Rio Grande do Norte state; and implement the I Meeting of MORHAN of Rio Grande do Norte state. This is an exploratory and descriptive study, with a qualitative approach, approved by the ERC No. 024/024/2012 Liga Norteriograndense Contra o Câncer. We used the contributions of the method and technique of oral history of life as methodological reference. We interviewed 10 individuals egress from preventorium Osvaldo Cruz in Natal/RN, sons of former patients proven to be residents in the city, of both sexes, older than 18, with cognitive, intellectual and emotional conditions preserved. The analysis of the histories obtained from collaborators was performed in the light of Thematic Content Analysis. The results and discussions are presented through two articles which meet the proposed objectives. The first, called Contextual Analysis on the children of leprosy patients in preventoriums aimed to record the phenomenon of children of leprosy patients in preventorium through four contextual levels, which identified the need to broaden the debate on public policy in the field of leprosy as a way to enable more effective measures to propagate in the search for harm reduction and direct consequences resulting from stigma and marginalization around patients and their healthy children, egress from preventoriums. The second, Leprosy and the denial of history: the story of separated children , aimed to know the life trajectory of children of leprosy patients who were institutionalized in preventoriums / educational establishments. In this article, we discuss the research question through the establishment of three main themes: 1. Losses and damages: disintegration and reintegration into the family and denied childhood; 2. Unforgettable: remarkable things you do not forget; and 3. Expectancy in living new situations: in search of other paths and destinations. These thematic axis highlighted the negative implications for the lives of the subjects, arising from the separation of their parents, leprosy patients at the time of compulsory isolation; however, has also been shown that this separation was not decisive in their life histories, once they have succeeded in providing a new sense of these experiences and lead their lives with dignity and fortitude. It was concluded that these children demonstrated resilience as form of defense and fighting stigma and prejudice, being able to reinvent themselves and build new paths and destinations
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