128 research outputs found

    An examination of communicative dialectical tensions and paradoxes encountered by Native American researchers in the field and in the academy

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    This study investigated the communicative dialectical tensions and paradoxical situations faced by Native researchers in the academy and in research with their own communities or with other Native communities. Thematic analysis was conducted on narratives from 12 semi-structured interviews from participants across the country. Three major themes emerged regarding communicative struggles for the participants when conducting research with Native communities: a dialectic of insider/outsider; challenge of developing positive communication; and concerns of appropriate and inappropriate behavior. Four major themes emerged with regards to communication challenges for the participants while working in the academy: insider-outsider dialectic, paradox of walking the talk, navigating the academy, and open and honest communication. This study also examined the successes encountered by the participants. Overall, the participants deemed success in the community as simply engaging in research with the community. Success in the academy centered on issues of support. Two important implications emerged from this study, one theoretical and one practical. First, the study identified two dialectics not previously discussed in dialectic approach/theory and thus makes a contribution to research/theorizing about dialectics. Specifically, there was the dialectic of insider/outsider related to spiritual identity and the dialectic of insider/outsider related to cultural knowledge. Second, the study illustrates the challenges that Native researchers face in conducting community research and in navigating the academy. The findings point to the importance of mentoring Native researchers in managing the dialectics and paradoxes by senior researchers who are sensitive to indigenous research. The key appears to be developing a mentoring program utilizing a CBPR approach

    Thermogravimetric analysis of resized glass and carbon fibers

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    The demand in growth for composite products over the years has as a consequence increased the volume of composite waste, requiring adequate waste management beyond incineration or landfilling practices. Current composite recycling methods cause an unwanted decrease in the mechanical performance of the recovered fibers due to the deterioration in their capacity to effectively interact with the polymeric matrix. Resizing the recycled glass and carbon fibers is a strategy to enable the rescue of their properties and, thus, the reuse of them on a new composite. This work focuses on the characterization of recycled and resized glass fiber and carbon fiber by Fourier transform infrared analysis (FTIR) and mainly by thermogravimetric analysis (TGA). Fibers were resized with solutions containing different concentrations of coupling agent and film former, in which the coupling agent was added only in the resizing formulation of the recycled glass fibers. Moreover, a study about the extraction of the resizing layer on the fiber’s surface by solvent and by burning is performed. The aim of this work is to determine the amount and composition of sizing on the fibers after the resizing process as well as the accuracy of TGA in the sizing characterization. The understanding of the resized fiber’s surface is important to the development of a suitable resizing method that could contribute to add value to the recycled and resized fibers and make them attractive to the market. As a result, the characterization methods have detected the presence of the sizing layer on the fiber’s surface in all studied samples. Furthermore, the amount and composition of this layer was determined. The extraction process revealed that the resizing layer had both physisorbed and chemisorbed portion either for recycled glass fibers or recycled carbon fiber. On the TGA technique, the analysis was not greatly affected by varying the heating rate from 10 K/min to 5 K/min, but great change occurred when furnace’s atmosphere was changed from nitrogen to air. In addition, TG analysis presented inaccuracies due to the small amount of sizing on the surface comparing to the mass of the fibers that was inserted on the crucible. Then, the use of other characterization methods were important to have better comprehension about the samples

    Inoculação de Lacazia loboi em camundongos BALB/c

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    In a previous study, the authors inoculated Swiss mice with Lacazia loboi (L. loboi) and succeeded in maintaining a granulomatous infiltrate and viable fungal cells up to one year and six months after inoculation. Considering the experimental work on paracoccidioidomycosis, 0.03 ml of a fungal suspension obtained from a biopsy of a Jorge Lobo's Disease patient were inoculated into both hind foot pads of 32 six week-old BALB/c mice of both sexes. The animals were sacrificed 1, 4, 7 and 10 months post inoculation. The suspension contained 1.3 x 10(6) fungi/ml and presented 38% viability. Seven months after inoculation, most of the animals presented profuse infiltrates consisting of isolated histiocytes, foreign body and Langhans' giant cells and a large number of fungi, most of them viable. Emergence of macroscopic lesions was observed during the 8th month. Based on fungal count, viability index before and after inoculation, presence of macroscopic lesions and histopathological findings similar to the findings in humans, the authors believe that BALB/c mice may be a good experimental model to study Jorge Lobo's Disease, mainly regarding therapeutic evaluation.Em trabalho anterior, os autores inocularam camundongos Suíços com o Lacazia loboi (L. loboi) conseguindo a manutenção de um infiltrado granulomatoso e células fúngicas viáveis por até um ano e 6 meses após a inoculação. Considerando-se trabalhos experimentais realizados na paracoccidioidomicose, eles inocularam 0,03 ml de suspensão fúngica, obtida de biópsia de lesão de um paciente portador da doença de Jorge Lobo, em ambos coxins plantares traseiros de 32 camundongos BALB/c, de ambos os sexos e com 6 semanas de idade. Os animais foram sacrificados com 1, 4, 7 e 10 meses pós-inoculação. A suspensão possuía 1.3x10(6) de fungos/ml e 38% de índice de viabilidade. Após 7 meses de inoculação a maioria dos animais já apresentava um infiltrado exuberante constituído por histiócitos isolados, células gigantes tipo corpo estranho e tipo Langhans, grande quantidade de fungos, na sua maior parte viáveis; no 8º mês observou-se o aparecimento de lesões macroscópicas. Tendo como base a contagem do número de fungos, índice de viabilidade antes e após inoculação, presença de lesões macroscópicas e achados histopatológicos semelhantes ao humano, os autores acreditam que os camundongos BALB/c possam se constituir em um bom modelo experimental para o estudo da doença de Jorge Lobo, principalmente com relação às pesquisas terapêuticas

    Dez anos de experiência com a Doença de Jorge Lobo no estado do Acre, região amazônica, Brasil

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    Jorge Lobo's disease is a cutaneous and subcutaneous mycosis that affects patients in the Amazon region. The number of patients is relatively small, but the real situation of the disease as public health problem is not known, because Jorge Lobo's disease is not a notifiable disease. This study aims to report the clinical evolution in patients affected and to determine the prevalence and areas of occurrence of the disease. A retrospective study was carried out based on the analysis of the clinical records, which included a collection of photographs of patients in the Department of Sanitary Dermatology, in Rio Branco, and patients seen in the interior of the state. In a decade, in Rio Branco, 249 cases of the disease were reported, 30 were females and 219 males. Of these patients, 153 had localized lesions, 94 of them were on one ear, 55 had multifocal lesions and 41 had disseminated lesions. The average time between the onset of symptoms and diagnosis was 19 years. The average age at the time of diagnosis was 53 years, and ages ranged from 14 to 96 years.A doença de Jorge Lobo é micose cutânea e subcutânea que afeta pessoas na região Amazônica. O número de pacientes é relativamente pequeno, no entanto, a real prevalência da doença como problema de saúde pública é pouco conhecida. A doença de Jorge Lobo não é de notificação compulsória. Este estudo teve como objetivo determinar a prevalência, as áreas de ocorrência da doença de Jorge Lobo, além de sua evolução clínica. Um estudo retrospectivo foi desenvolvido com base na análise de prontuários de pacientes, incluindo documentação fotográfica dos mesmos, que foram atendidos no Departamento de Dermatologia Sanitária em Rio Branco e no interior do Estado. Foram registrados 249 casos em uma década em Rio Branco, 30 mulheres e 219 homens. Do total 153 apresentavam lesões localizadas, 94 lesões em apenas uma orelha, 55 lesões multifocais e 41 lesões disseminadas. A média de tempo entre o início dos sintomas e o diagnóstico foi de 19 anos. A média de idade no momento do diagnóstico foi de 53 anos, e as idades variaram de 14 a 96 anos

    Serodiagnosis of leprosy and follow-up of household contacts using a commercial rapid test containing ND-O/LID-1 antigens

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    Introduction: Early diagnosis of leprosy, including the diagnosis of sub-clinical disease in contacts of known cases, would be a major advance. The signs of early leprosy are often difficult to assess and a reliable diagnostic test could play an important role in identifying cases and thus reducing transmission. Methods: Subjects were recruited at Centro de Saude Jardim Guanabara, Rondonopolis, Mato Grosso State, Brazil. Sera were obtained from 174 recently diagnosed leprosy patients, 409 household contacts, 53 endemic controls and 12 patients with active TB. 186 of the household contacts were re-tested on subsequent visits. Both the NDO-LID rapid test (Orange Life, Rio de Janeiro, Brazil) and an anti-PGL-1 ELISA test were used on all samples for comparison. Results: LID-1 was positive in 25 of 125 PB cases (20%), but in 41 of 49 MB cases (83.7%), while the anti-PGL-1 ELISA was positive in 8 (6.4%) and 35 (71.4%) cases, respectively. Specificity for LID-1 was 85% and for the anti-PGL-1 ELISA, 97%. Amongst household contacts, 9 of 409 (2.2%) were positive on the LID-1 test, and a further 51 (115%) were weakly positivealthough 9 cases of leprosy were subsequently identified amongst these contacts, 6 had tested negative, 2 were weakly positive and only 1 had been positive. Conclusion: The ND-O-LID-1 assay can be easily performed by the addition of serum to the assay device, and thus can be applied in resource-poor settings. The test was found to be useful for the detection of multibacillary cases, which in the long term will help to reduce transmission of the disease. This is a specific test, but it is not very sensitive for early detection of leprosy in household contacts and paucibacillary forms.Inst Lauro Souza Lime, Bauru, SP, BrazilHlth Ctr Rondonopolis MT, Rondonopolis, BrazilFed Univ Sao Paulo Unifesp, Dept Dermatol, Sao Paulo, BrazilUniv Fed Sao Paulo Unifesp, Dept Dermatol, Sao Paulo, BrazilWeb of Scienc

    Effects of mesophilic and thermophilic anaerobic digestion of sewage sludge on different polymers : Perspectives on the potential of the treatment to degrade microplastics

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    Sewage sludge is produced during municipal wastewater treatment and can be further treated to be used for soil applications due to its high nutrient and carbon content. Anaerobic digestion is often used to manage sewage sludge. However, sewage sludge has a high load of microplastics that can be transferred to the soil, causing a burden to the environment. Some researchers suggest that anaerobic digestion could be used as a method to remove microplastics from sewage sludge, while others have shown the opposite. In this study, a variety of commodity polymers (LLDPE, HDPE, PP, PS, PET, uPVC, PA66 and SBR) are tested under mesophilic (35 °C) and thermophilic (55 °C) anaerobic digestion to evaluate their degradation after the process. As 1 mm thick sheets of polymers were used, in terms of diffusion they were considered to correspond to microplastics. Different characterization methods were used to access the visual, chemical, mechanical and thermal changes caused by anaerobic digestion. The results showed evidence of polymer degradation, for example, surface smoothening of LLDPE, HDPE and PP, embrittlement of PS and uPVC, hydrolysis of PET, plasticization of PA66, and surface cracking of SBR. However, although some changes in properties happened, anaerobic digestion could not comprehensively degrade the studied polymers. Therefore, this study suggests that anaerobic digestion of sewage sludge, at the conditions tested, is not able to be used as a method to eliminate microplastics from the sewage sludge before it is added to the soil.Peer reviewe

    Accidental Jorge Lobo's disease in a worker dealing with Lacazia loboi infected mice: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Jorge Lobo's disease (Lacaziosis) is a subcutaneous infection of humans living in the Amazon region of Latin America, and in dolphins inhabiting the east coastal areas of the United States. The disease mainly affects people from rural areas living or working in close contact with vegetation and aquatic environments. Most patients refer having developed lesions after accidental trauma with plant thorns or insect bites. Inter-human transmission has never been confirmed suggesting that <it>Lacazia loboi </it>is acquired from environmental propagules.</p> <p>Case presentation</p> <p>We report the case of a 41-year-old woman from São Paulo, Brazil, a non-endemic area of Jorge Lobo's disease, with <it>L. loboi </it>skin infection most likely accidentally acquired while manipulating experimentally infected mice in the laboratory.</p> <p>Conclusion</p> <p>Because many patients with Jorge Lobo's disease do not recall accidental skin trauma before their infections, the possibility of accidentally acquired Jorge Lobo's disease through unnoticed broken skin should be considered during the clinical investigation of nodular skin diseases in people who have contact with the fungus or who live in endemic areas. This is the second report of animal to human transmission of this disease.</p

    In vitro and in situ activation of the complement system by the fungus Lacazia loboi

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    Since there are no studies evaluating the participation of the complement system (CS) in Jorge Lobo's disease and its activity on the fungus Lacazia loboi, we carried out the present investigation. Fungal cells with a viability index of 48% were obtained from the footpads of BALB/c mice and incubated with a pool of inactivated serum from patients with the mycosis or with sterile saline for 30 min at 37 ºC. Next, the tubes were incubated for 2 h with a pool of noninactivated AB+ serum, inactivated serum, serum diluted in EGTA-MgCl2, and serum diluted in EDTA. The viability of L. loboi was evaluated and the fungal suspension was cytocentrifuged. The slides were submitted to immunofluorescence staining using human anti-C3 antibody. The results revealed that 98% of the fungi activated the CS by the alternative pathway and no significant difference in L. loboi viability was observed after CS activation. In parallel, frozen histological sections from 11 patients were analyzed regarding the presence of C3 and IgG by immunofluorescence staining. C3 and IgG deposits were observed in the fungal wall of 100% and 91% of the lesions evaluated, respectively. The results suggest that the CS and immunoglobulins may contribute to the defense mechanisms of the host against L. loboi.Considerando que não existe nenhum estudo avaliando a participação do sistema complemento (SC) na doença de Jorge Lobo e sua atividade sobre o fungo Lacazia loboi, realizamos o presente trabalho. Os fungos foram obtidos dos coxins plantares de camundongos BALB/c com índice de viabilidade de 48% e, em seguida, foram incubados com pool de soro inativado de pacientes ou com solução salina estéril (SSE) por 30 min, a 37 ºC. Os tubos foram incubados, por 2 h, com pool de soro AB+ sem inativar, inativado, diluído em EGTA-MgCl2 e EDTA. A viabilidade do L. loboi foi avaliada e a suspensão fúngica foi citocentrifugada. As lâminas foram submetidas à técnica de imunofluorescência empregando o anticorpo anti-C3 humano. Os resultados revelaram que 98% dos fungos ativaram o SC pela via alternativa e que não houve diferença significante na viabilidade do L. loboi após ativação do SC. Em paralelo, cortes histológicos congelados de 11 pacientes foram avaliados quanto à presença de C3 e IgG, pela técnica de imunofluorescência. Foram encontrados depósitos de C3 e de IgG na parede dos fungos em 100% e 91% das lesões avaliadas, respectivamente. Os resultados sugerem que o SC e as imunoglobulinas poderiam contribuir nos mecanismos de defesa do hospedeiro contra o L. loboi

    In situ damage characterization of CFRP under compression using high-speed optical, infrared and synchrotron X-ray phase-contrast imaging

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    The strain rate dependency and failure modes of carbon fiber reinforced plastic (CFRP) laminate were investigated under out-of-plane compressive loading. Simultaneous high-speed optical and infrared imaging were used to measure full-field deformation and temperature in the dynamically loaded specimens. The damage initiation and propagation inside the CFRP laminates at high strain rates were characterized using in-situ ultra-fast synchrotron X-ray phase contrast imaging (XPCI). The visually observed damage onset occurs at the strain value of 4.2 ± 0.6% as a transverse shear fracture at the free edge of specimens. The local temperature increases significantly to 185 °C due to damage initiation at high strain rates, while at low strain rates the temperature rise occurs after the final shear band forms. The XPCI and post-failure analysis provide an integrated perspective on the formation of a diagonal shear crack and disintegration of the specimen into two pieces with the fracture of plies in the in-plane transverse direction. Scanning electron microscopic (SEM) study was integrated with XPCI results to append the time scale for the post-mortem failure pattern as well as the length scale for microcracks and filament-level failure.Peer reviewe
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