Universidade Federal da Bahia
  • Salvador, Bahia, Brazil
Recent publications
Resumo Diante dos impactos ambientais associados à produção do cimento Portland convencional, o estudo de cimentos especiais de reduzido impacto ambiental tem sido uma tendência. Neste contexto, os cimentos contendo ye’elimita (YCC) se destacam devido à baixa emissão de CO2. Apesar das vantagens ambientais, a alta demanda por alumínio limita economicamente a produção destes cimentos. Uma alternativa para viabilizar a sua produção é o uso de matérias-primas residuais como fonte de Al2O3, a exemplo do SFCC (catalizador gasto do craqueamento catalítico de leito fluidizado). Diante disso, este trabalho tem como objetivo avaliar a hidratação na idade inicial de cimentos YCC produzidos a partir do coprocessamento do SFCC. Para isso, foram produzidos seis clínqueres com diferentes teores de ye’elimita, com e sem SFCC. Estes foram caracterizados por DRX/Rietveld. As pastas foram avaliadas por TG/DTG e DRX/Rietveld para compreender o mecanismo de hidratação em idade inicial destes cimentos. Foi possível sintetizar as principais fases dos YCC, nos clínqueres com e sem SFCC. Além disso, na idade avaliada, as pastas com e sem SFCC apresentaram composição de fases comparáveis indicando o potencial de coprocessamento do SFCC neste tipo de cimento.
Resumo O sisal (Agave sisalana) é uma planta explorada nas regiões semiáridas do Brasil para produção de fibras, mas o escapo floral do sisal (flecha) é coletado e frequentemente queimado causando problemas ambientais, até mesmo pelo descarte irregular. Para contornar este cenário, o objetivo deste trabalho foi produzir painéis reconstituídos usando a flecha do sisal e resina poliuretana à base de mamona. Os painéis foram obtidos empregando 175 g do miolo da flecha de sisal triturada com dimensões inferiores a 2 mm e adotando 10% de resina poliuretana à base de mamona e as amostras foram prensadas com tensão de 2 MPa. Avaliou-se no painel reconstituído, através da NBR 14810-1 (ABNT, 2013) e NBR 14810-2 (ABNT, 2018) as propriedades físicas: umidade, densidade, inchamento e absorção; bem como as propriedades mecânicas: MOR, MOE, força de ligação e compressão paralela. Os resultados encontrados mostram que o painel é classificado como de baixa densidade (419,8 kg/m³), e de propriedades físicas e mecânicas semelhantes a outros painéis de mesma classificação da literatura. Para MOR e MOE foram encontrados 5,24 MPa e 147,49 MPa de média, respectivamente. Já os ensaios de tração perpendicular e compressão paralela obtiveram resultados de 0,14 MPa e 1,14 MPa, respectivamente.
The present paper evaluated the potential application of the functionally graded material (FGM) concept to develop more durable concrete to carbonation, one of the main degradation mechanisms of reinforced concrete structures. Accelerated carbonation tests with controlled temperature (27 ( 2°C), CO2 concentration (3 ( 0.5%) and humidity (65 ( 5%) were carried out in homogeneous concretes and with functional gradation in which the porosity of the material was varied across the slices. For the manufacture of graded concrete specimens, concretes with water/cement ratios equal to 0.35, 0.45, and 0.55 were produced, with lower porosity (w/c = 0.35) close to the surface of the specimen. The advance of the carbonation front was evaluated after 8, 9, 10, 14, and 24 weeks of accelerated exposure, using the chemical indicator phenolphthalein. The results show that the functionally graded concrete had a carbonation coefficient (K) slightly higher than that of the concrete with a w/c ratio equal to 0.35 (1.71 and 1.54 mm.week-0.5, respectively) and much lower than concrete with water-cement ratio equal to 0.45 (2.31 mm.week-0.5) and 0.55 (3.78 mm.week-0.5). This demonstrates that functional grading can be an efficient method to increase the durability of concrete elements subject to carbonation.
Resumo Este artigo tem por objetivo evidenciar a necessidade do reconhecimento do campo dos Direitos Raciais, para reflexão e elucidação da complexidade das relações étnico-raciais no Brasil, com fito na superação das desigualdades e discriminações estruturais da sociedade e do direito, conformadas pela modernidade/colonialidade. Através da análise do discurso presente em narrativas que remetem a casos de suicídio, argumenta-se que a negação e silenciamento da diversidade étnica, cultural e epistêmica das identidades contracolonizadoras implicam em sua condenação ao sofrimento físico e psíquico como condição existencial e que, ao serem ignoradas pela episteme jurídica dominante, ratificam o Direito como instrumento de criação e manutenção de privilégios e exclusões. Conclui-se quanto à necessidade de ruptura da univocidade do direito, que performa ao mesmo tempo o racismo epistêmico e o racismo jurídico, por meio do campo dos Direitos Raciais, voltado às investigações atinentes às condições sócio-histórico-culturais que relegam individualidades fecundas à sub-humanidade jurídica, às investigações relativas às dimensões de humanidade que lhes são estruturalmente negadas, e à revisão e proposição normativa decolonial.
Predicting the spread of invasive species and understanding the role of niche dynamics in niche transferability are critical challenges in the management of biological invasions, both theoretically and practically. We used complementary species distribution modelling approaches, such as multivariate niche analysis and reciprocal distribution models, to test the niche conservatism hypothesis and to predict the potential distribution of the fishhook waterflea, Cercopagis pengoi. Our analysis indicated a significant similarity between its native and invasive ranges, suggesting that a subset of the Ponto-Caspian propagules may have been the founders of European populations. However, our results contradict the niche conservatism hypothesis, showing that C. pengoi has not fully occupied the available niche within its current invasive ranges. Moreover, we observed a notable niche expansion, reflecting a significant shift in niche following its intercontinental introduction in North America. Given the suitability of new environments for the expansion of C. pengoi and its tendency to evade detection prior to population surges, we recommend a focus on early detection through monitoring of both water columns and bottom sediments. This should be complemented by strict enforcement of ballast water regulations to curtail its spread in North America, Europe, and other suitable non-native regions globally.
Multiple Myeloma (MM) is a hematological malignancy characterized by the clonal proliferation of plasma cells within the bone marrow. Diagnosing MM presents considerable challenges, involving the identification of plasma cells in cytology examinations on hematological slides. At present, this is still a time-consuming manual task and has high labor costs. These challenges have adverse implications, which rely heavily on medical professionals’ expertise and experience. To tackle these challenges, we present an investigation using Artificial Intelligence, specifically a Machine Learning analysis of hematological slides with a Deep Neural Network (DNN), to support specialists during the process of diagnosing MM. In this sense, the contribution of this study is twofold: in addition to the trained model to diagnose MM, we also make available to the community a fully-curated hematological slide dataset with thousands of images of plasma cells. Taken together, the setup we established here is a framework that researchers and hospitals with limited resources can promptly use. Our contributions provide practical results that have been directly applied in the public health system in Brazil. Given the open-source nature of the project, we anticipate it will be used and extended to diagnose other malignancies.
Introduction It is not yet clear whether cardiac surgery by mini-incision (minimally invasive cardiac surgery [MICS]) is overall less painful than the conventional approach by full sternotomy (FS). A meta-analysis is necessary to investigate polled results on this topic. Methods PubMed®/MEDLINE, Cochrane CENTRAL, Latin American and Caribbean Health Sciences Literature (or LILACS), and Scientific Electronic Library Online (or SciELO) were searched for all clinical trials, reported until 2022, comparing FS with MICS in coronary artery bypass grafting (CABG), mitral valve surgery (MVS), and aortic valve replacement (AVR), and postoperative pain outcome was analyzed. Main summary measures were the method of standardized mean differences (SMD) with a 95% confidence interval (CI) and P-values (considered statistically significant when < 0.05). Results In AVR, the general estimate of postoperative pain effect favored MICS (SMD 0.87 [95% CI 0.04 to 1.71], P=0.04). However, in the sensitivity analysis, there was no difference between the groups (SMD 0.70 [95% CI -0.69 to 2.09], P=0.32). For MVS, it was not possible to perform a meta-analysis with the included studies, because they had different methodologies. In CABG, the general estimate of the effect of postoperative pain did not favor any of the approaches (SMD -0.40 [95% CI -1.07 to 0.26], P=0.23), which was confirmed by sensitivity analysis (SMD -0.02 [95% CI -0.71 to 0.67], P=0.95). Conclusion MICS was not globally less painful than the FS approach. It seems that postoperative pain is more related to the degree of tissue retraction than to the size of the incision.
South America is a pivotal paleontological setting for Late Quaternary megafaunal research. Nonetheless, its paleobiogeography and paleoecology, and the causes for the recent extinction of megafauna in the Late Pleistocene/Early Holocene are not yet fully understood. This study aimed to investigate the potential geographical distribution and historically intertropical stable areas (HISAs) of South American megafauna. We generated maps using Paleo‐Species Distribution Models for 12 megafaunal taxa (11 herbivores and one carnivore) during interglacial and glacial periods in the Late Quaternary: 120 and 21 ka. Our models, together with isotopic data, show that the HSIAs occurred mainly in low‐altitude plains (<1000 m) and were superimposed on seasonal dry forest biomes. We propose the occurrence of two HSIAs: the West Intertropical Region and the Brazilian Intertropical Region, the latter being redefined. We suggest that the Brazilian Intertropical Region is much smaller than previously proposed, but was still a key zoogeographical region for megafauna in South America during the Late Pleistocene.
Antigenic similarities between Zika virus (ZIKV) and other flaviviruses pose challenges to the development of virus-specific diagnostic tools and effective vaccines. Starting with a DNA-encoded one-bead-one-compound combinatorial library of 508,032 synthetic, non-natural oligomers, we selected and characterized small molecules that mimic ZIKV epitopes. High-throughput fluorescence-activated cell sorter-based bead screening was used to select molecules that bound IgG from ZIKV-immune but not from dengue-immune sera. Deep sequencing of the DNA from the “Zika-only” beads identified 40 candidate molecular structures. A lead candidate small molecule “CZV1-1” was selected that correctly identifies serum specimens from Zika-experienced patients with good sensitivity and specificity (85.3% and 98.4%, respectively). Binding competition studies of purified anti-CZV1-1 IgG against known ZIKV-specific monoclonal antibodies (mAbs) showed that CZV1-1 mimics a nonlinear, neutralizing conformational epitope in the domain III of the ZIKV envelope. Purified anti-CZV1-1 IgG neutralized infection of ZIKV in cell cultures with potencies comparable to highly specific ZIKV-neutralizing mAbs. This study demonstrates an innovative approach for identification of synthetic non-natural molecular mimics of conformational virus epitopes. Such molecular mimics may have value in the development of accurate diagnostic assays for Zika, as well as for other viruses.
Spathodea campanulata Beauv. (Bignoniaceae) is a plant frequently employed in the ornamentation of public squares and gardens, attributed to its rapid growth and showy flowers. However, its use is controversial due to the potentially toxic nectar, which can lead to significant mortality rates among various stingless bee species in Brazil, posing a risk to native biodiversity and disrupting natural ecosystems. The aim of this study was to quantify and identify the species of stingless bees found dead within the flowers of the Spathodea campanulata plant. This investigation was conducted at the Ondina Campus of the Federal University of Bahia (UFBA), Brazil. Over a 15-day flowering period, 86 flowers from three specimens of this species were collected. After flower collection, the dead insects found within the flowers were extracted, stored, and identified at the Laboratory of Insect Bionomics, Biogeography, and Systematics (BIOSIS) at UFBA. The analysis revealed that all floral visitors were Hymenoptera insects, with 98.1% identified as bees (Apidae and Meliponini). In conclusion, S. campanulataflowers contain toxic compounds with insecticidal properties, leading to increased mortality among certain Melipona bee species. Melipona scutellaris and Apis mellifera bees are occasional visitors of the S. campanulata flowers; hence the lower mortality rates of these species. Given the damage caused by S. campanulata on native biodiversity, it is advised to avoid cultivating it in public squares, gardens, or in proximity to bee hives. Keywords stingless bee; toxic plant; toxicity; bee mortality
This work presents supervised machine learning techniques for the problem of virtualization design with protection over elastic optical networks (EONs) for predicting the total number of used spectrum slots to support all traffic demands. It considers virtual optical networks (VONs) subject to protection and proposes learning techniques to solve the link capacity problem of EONs with virtualization faster than traditional integer linear programming (ILP) formulations, but keeping the finds near to the optimal ones. The performance of the models were evaluated using statistical metrics, along with the time for training and performing inferences, both using quantitative and qualitative analysis. They showed that the proposed method is effective for predicting the number of required slots (bandwidth) on physical substrate subject to several VONs.
Purpose This study aimed to characterize the histopathological immunohistochemical features of chronic sclerosing sialadenitis, emphasizing the IgG4-related disease. Methods Seventeen cases of chronic sclerosing sialoadenitis were examined for histopathological aspects, (inflammation, fibrosis, glandular parenchyma, and lymphoid follicles) and immunohistochemistry (BCL2, CD3, CD20, CD34, CD163, p63, cyclin D1, mast cell, SMA, S100A4, IgG, and IgG4) which were scored. IgG4-related disease features were investigated. Demographic and clinical data were also collected. Results Males predominated (10:7), with an average lesion size of 3.9 cm. Common histopathological findings included reduced acinar parenchyma, lymphoid follicle formation, and ductular proliferation. CD3-positive T lymphocytes and CD34- and SMA-positive stromal fibroblasts were abundant. Nine cases (53%) showed sialoliths and three cases met the criteria for IgG4-related disease. Conclusion CSS of the submandibular gland represents a reactive pattern rather than IgG4-RD as only 3 cases seemed to be related to IgG4-RD. The immunohistochemical profile revealed an abundant population of CD3-positive T lymphocytes, as opposed to regulatory proteins such as cyclin D1, demonstrating that populations of CD34- and SMA-positive stromal fibroblasts contribute to the fibrosis characteristic of CSS. In addition, our results provide a comprehensive insight into the study of CSS and its relationship with IgG4-RD.
Objective To analyze the factors associated with the individual use of insect repellent by women of childbearing age living in area endemic for arboviruses in Fortaleza, Brazil. Methods This is a cohort study carried out between 2018 and 2019 with women aged between 15 and 39 years in Fortaleza, state of Ceará, Brazil. A total of 1,173 women users of one of the four selected primary health care units participated in the study. The outcome was divided into: continued use, discontinued use, and nonuse of insect repellent. Crude and adjusted multinominal logistic regression analysis was carried out guided by a hierarchical model, with presentation of the respective odds ratio (OR) and 95% confidence intervals (95%CI). The independent variables include: socioeconomic and demographic data, environmental and sanitary characteristics, knowledge of the insect repellent, and behavioral and pregnancy-related aspects. Results Only 28% of the participants reported using insect repellent during the two waves of the cohort. Women with higher education (OR=2.55; 95%CI 1.44–4.51); who are employed (OR=1.51; 95%CI 1.12–2.03); who received guidance from healthcare professionals (OR=1.74; 95%CI 1.28–2.36) and the media (OR=1.43; 95%CI 1.01–2.02); who intensified precautions against mosquitoes during the epidemic (OR=3.64; 95%CI 2.29–5.78); and who were pregnant between 2016 and 2019 (OR=2.80; 95%CI 1.83–4.30) had increased odds for continued use of insect repellent. Conclusion The use of insect repellent among women of childbearing age was associated with a higher level of education, employment, guidance on insect repellent provided by healthcare professionals and the media, behavioral changes to protect against mosquitoes during the Zika virus epidemic, and pregnancy when occurring as of the beginning of the epidemic period. Keywords: Public health; Arboviruses; Zika virus; Women’s health; Insect repellents; Vulnerable populations
Objective To evaluate the inflammatory potential of diets, the specific dietary contributors to said inflammatory potential, the nutritional adequacy of these diets, and the association between the dietary inflammatory potential and sleep complaints among residents of long-term care facilities. Materials and Methods The present is a cross-sectional, quantitative, and exploratory study, with a convenience pilot sample from two long-term care facilities. To assess sleep complaints, the sleep domain of the Nottingham Health Profile was applied, as well as a question about daytime napping. To evaluate the inflammatory potential of the diet, the Dietary Inflammatory Index (DII) was calculated. Results The participants presented energy and protein intakes below the recommendation. The intake of saturated fatty acids, omega 6, dietary fiber, vitamins D, E, B6, and magnesium were inadequate in some of the participants. The mean score on the DII was of 1.6, representing a more proinflammatory potential, due to insufficient intake of anti-inflammatory components. The foods with the most significant inflammatory effect consumed were whole milk and butter. On the other hand, those with less inflammatory potential were beans, beets, coffee, and sweet potatoes. No significant association was observed between the sleep complaints and the DII. Conclusion The data showed inadequacy of many nutrients and a proinflammatory potential regarding the diet in the long-term care facilities. However, the DII was not significantly associated with sleep complaints in our sample. The present study highlights the need for greater attention to meal planning in these institutions.
Dural Arteriovenous Fistulas (dAVFs) of the anterior cranial fossa (ACF) are uncommon but carry a high risk of hemorrhage and pose substantial treatment challenges. Recent advancements in endovascular treatment (EVT), including the introduction of novel liquid embolic agents, have markedly bolstered EVT’s role in managing ACF-dAVFs, with notable series published in the last five years. We aimed to assess the feasibility, safety, and efficacy of EVT for ACF-dAVFs. We searched Medline, Scopus, Web of Science, and Cochrane Library databases following PRISMA guidelines. Eligible studies included those with ≥ 5 patients undergoing embolization of ACF-dAVFs, detailing both angiographic and clinical outcomes. We used single proportion analysis with 95% confidence intervals under a random-effects model, I² to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Publication bias was assessed by funnel-plot analysis and Egger’s test. Outcomes included complete occlusion following embolization, unsuccessful endovascular embolization attempts, incomplete occlusion following embolization, symptom resolution or clinical improvement following embolization, recurrence; procedure-related complications, morbidity, and mortality. Additionally, a subanalysis for studies exclusively utilizing Onyx™ embolic system was done. Eighteen studies comprising 231 ACF-dAVF were included. Unsuccessful endovascular embolization attempts rate was 2%. Complete occlusion rate was 85%, with 4% of complications. Incomplete occlusion rate was 10%. Successfully embolized patients experienced either symptom resolution or clinical improvement in 94% of cases. Morbidity and mortality rates were 1% and 0%, respectively. Onyx subanalyses showed an overall rate of 0% for unsuccessful attempts, 95% for complete occlusion, and 5% for incomplete occlusion. Symptom resolution or clinical improvement was 98% and recurrence rate was 0%. EVT for ACF-dAVF is highly feasible, effective, and safe, with a low rate of complications, morbidity, and mortality. The subanalyses focusing on Onyx embolizations revealed superior efficacy and safety outcomes compared to the findings of the primary analyses involving all included studies.
A spectral criterion involving the model parameters is given for the existence and uniqueness of a periodically correlated and seasonal non‐negative integer‐valued autoregressive process. The structure of the mean and covariance functions of the periodically stationary distribution of the model is derived using its implicit state‐space representation. Two infinite series representations for the process, the moving average, and the immigrant generation, are established. Based on the latter representation, a novel and parallelizable simulation method is proposed to generate the process.
The human T-lymphotropic virus type 1 (HTLV-1) affects over 5 million people worldwide and is endemic in Brazil. Though HTLV-1 is a notifiable disease, the last epidemiological report regarding HTLV-1 infection covered the period from 2012 to 2019. To understand the specific challenges and to develop the best strategies for controlling HTLV-1 infection, it is important to know the characteristics of each region providing care to people living with this virus. This descriptive cross-sectional study evaluated patients treated at the HTLV reference center in Vitória da Conquista, Bahia, Brazil, between July 2021 and August 2022. The data were obtained through the analysis of medical records and routine clinical consultations. A total of 67 patients were evaluated, with 79.1% being female, 79.1% identifying as black, indigenous, and people of color, 37.31% being married, 80.6% identifying as heterosexual, and 59.7% reporting inconsistent condom use. Additionally, 37.3% of the patients were diagnosed with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic disease with a considerable effect on the quality of life. Furthermore, 53.7% of the patients had incomplete/complete elementary education, and 52.2% had an income of up to one minimum wage. The data highlight the necessity for more specific public policies (such as health education strategies, aimed at reducing the number of new infections) targeting the described at-risk population.
En este ensayo presento reflexiones preliminares sobre tecnologías digitales como nuevas formas de promoción de la salud en el mundo contemporáneo. Primero, introduzco los conceptos de tecnología, realidad, presencia, realidad virtual y realidad extendida, a partir del realismo crítico. Segundo, discuto el concepto emergente de metapresencialidad como fundamental para la apropiación sociotécnica de tecnologías digitales en los campos de la educación y de la salud. Tercero, analizo críticamente la noción de Educación a Distancia en contraste con la idea de espacios metapresenciales de aprendizaje, en el contexto de un modelo innovador de educación superior. En cuarto lugar, discuto brevemente la Salud Digital como conjunto de saberes, técnicas y prácticas capaz de superar el dualismo “tecnologías duras” vs “tecnologías blandas” en la salud. Finalmente, evalúo cuestiones epistemológicas propias del campo de la Salud Colectiva, con el objetivo de redefinir la telesalud como cuidado de salud mediado por metapresencialidad.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
7,888 members
Luciano Oliveira
  • Departamento de Ciência da Computação
Federico Costa
  • Instituto de Saúde Coletiva (ISC)
Ruy Kikuchi
  • Instituto de Geociências
Antonio L. Apolinario Jr.
  • Departamento de Ciência da Computação
Information
Address
Rua Augusto Viana, s/n - Palácio da Reitoria, Canela, 40110-909, Salvador, Bahia, Brazil
Head of institution
João Carlos Salles Pires da Silva
Phone
+55 71 3283-7018
Fax
55-71-32836730