2,134 research outputs found
Localized Faraday patterns under heterogeneous parametric excitation
Faraday waves are a classic example of a system in which an extended pattern
emerges under spatially uniform forcing. Motivated by systems in which uniform
excitation is not plausible, we study both experimentally and theoretically the
effect of heterogeneous forcing on Faraday waves. Our experiments show that
vibrations restricted to finite regions lead to the formation of localized
subharmonic wave patterns and change the onset of the instability. The
prototype model used for the theoretical calculations is the parametrically
driven and damped nonlinear Schr\"odinger equation, which is known to describe
well Faraday-instability regimes. For an energy injection with a Gaussian
spatial profile, we show that the evolution of the envelope of the wave pattern
can be reduced to a Weber-equation eigenvalue problem. Our theoretical results
provide very good predictions of our experimental observations provided that
the decay length scale of the Gaussian profile is much larger than the pattern
wavelength.Comment: 10 pages, 9 figures, Accepte
Simulation and evaluation of deep learning autoencoders for image compression in multi-UAV network systems
Mobile multi-robot systems are versatile alternatives
for improving single-robot capacities in many applications, such
as logistics, environmental monitoring, search and rescue, photogrammetry,
etc. In this sense, this kind of system must have a
reliable communication network between the vehicles, ensuring
that information exchanged within the nodes has little losses. This
work simulates and evaluates the use of autoencoders for image
compression in a multi-UAV simulation with ROS and Gazebo
for a generic surveillance application. The autoencoder model
was developed with the Keras library, presenting good training
and validation results, with training and validation accuracy
of 70%, and a Peak Signal Noise Ratio (PSNR) of 40dB. The
use of the CPU for the simulated UAVs for processing and
sending compressed images through the network is 25% faster.
The results showed that this compression methodology is a good
choice for improving the system’s performance without losing too
much information.The authors thank CEFET/RJ, UFF, UFRJ, and the Brazilian
research agencies CAPES, CNPq, and FAPERJ. Besides, the authors are grateful to the Foundation for Science and Technology
(FCT, Portugal) for financial support through national
funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020
and UIDP/05757/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
Doxycycline degradation by the oxidative Fenton process
Doxycycline is a broad-spectrum tetracycline occurring in domestic, industrial and rural effluents, whose main drawback is the increasing emergence of resistant bacteria. This antibiotic could be degraded by the so-called Fenton process, consisting in the oxidation of organic pollutants by oxygen peroxide (H2O2) in the presence of Fe2+. Experiments were performed according to an experimental Rotational Central Composite Design to investigate the influence of temperature (0 \u2013 40.0\ub0C), H2O2 concentration (100 \u2013 900 mg/L) and Fe2+ concentration (5 \u2013 120 mg/L) on residual doxycycline and total organic carbon concentrations. Whereas the final residual doxycycline concentration ranged from 0 to 55.8 mg/L, the oxidation process proved unable to reduce the total organic carbon by more than 30%. The best operating conditions were concentrations of H2O2 and Fe2+ of 611 and 25 mg/L, respectively, and temperature of 35.0\ub0C, but the analysis of variance revealed that only the first variable exerted a statistically-significant effect on the residual doxycycline concentration. These results suggest possible application of this process in the treatment of doxycycline-containing effluents and may be used as starting basis to treat tetracycline-contaminated effluents
Estudo da partição de fitase produzida por Aspergillus niger var. phoenicis utilizando bioconversão extrativa em sistemas de duas fases aquosas PEG/citrato
Existem diversos métodos tradicionais que são utilizados para extratir biomoléculas produzidas por fermentação convencional. Um método alternativo é o sistema de duas fases aquosas, o qual foi desenvolvido para a extração de bioprodutos. A bioconversão extrativa trata-se de um sistema de duas fases aquosas que integra cultivo microbiológico à produção e recuperação do bioproduto. Fitases são fosfatases específicas que estão envolvidas na catálise do ácido fitico. O objetivo deste trabalho foi estudar a partição da fitase produzida por A. niger var. phoenicis por bioconversão extrativa utilizando PEG/citrato. Realizou-se um planejamento fatorial completo 25, estudando as seguintes variáveis: massa molar do PEG, concentração do PEG, concentração de citrato, pH e agitação, onde obteve-se como variável-resposta o coeficiente de partição em atividade (KATIV). Neste trabalho conseguiu-se um coeficiente de partição de 25,77 utilizando MPEG (8000 g/mol), CPEG, (26,0% m/m), CCIT (20,0% m/m), pH (6,0) e agitação (100 rpm). Através dos resultados obtivos, pode-se concluir que a fitase utilizada no presente estudo apresenta uma tendência de particionar para a fase superior do sistema (K>1). A técnica de fermentação extrativa utilizando SDFA PEG/citrato demonstrou ser promissora para extração de fitase produzida por A. niger var. phoenicis, podendo ser aplicada na composição de rações comerciais
ABC 2 -SPH risk score for in-hospital mortality in COVID-19 patients: development, external validation and comparison with other available scores
Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Hospitalitzacions; MortalitatCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Hospitalizaciones; MortalidadCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Hospitalizations; MortalityObjectives
The majority of available scores to assess mortality risk of coronavirus disease 2019 (COVID-19) patients in the emergency department have high risk of bias. Therefore, this cohort aimed to develop and validate a score at hospital admission for predicting in-hospital mortality in COVID-19 patients and to compare this score with other existing ones.
Methods
Consecutive patients (≥ 18 years) with confirmed COVID-19 admitted to the participating hospitals were included. Logistic regression analysis was performed to develop a prediction model for in-hospital mortality, based on the 3978 patients admitted between March–July, 2020. The model was validated in the 1054 patients admitted during August–September, as well as in an external cohort of 474 Spanish patients.
Results
Median (25–75th percentile) age of the model-derivation cohort was 60 (48–72) years, and in-hospital mortality was 20.3%. The validation cohorts had similar age distribution and in-hospital mortality. Seven significant variables were included in the risk score: age, blood urea nitrogen, number of comorbidities, C-reactive protein, SpO 2 /FiO 2 ratio, platelet count, and heart rate. The model had high discriminatory value (AUROC 0.844, 95% CI 0.829–0.859), which was confirmed in the Brazilian (0.859 [95% CI 0.833–0.885]) and Spanish (0.894 [95% CI 0.870–0.919]) validation cohorts, and displayed better discrimination ability than other existing scores. It is implemented in a freely available online risk calculator (https://abc2sph.com/).
Conclusions
An easy-to-use rapid scoring system based on characteristics of COVID-19 patients commonly available at hospital presentation was designed and validated for early stratification of in-hospital mortality risk of patients with COVID-19.This study was supported in part by Minas Gerais State Agency for Research and Development ( Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG ) [grant number APQ-00208-20], National Institute of Science and Technology for Health Technology Assessment ( Instituto de Avaliação de Tecnologias em Saúde – IATS )/ National Council for Scientific and Technological Development ( Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq ) [grant number 465518/2014-1], and CAPES Foundation ( Coordenação de Aperfeiçoamento de Pessoal de Nível Superior ) [grant number 88887.507149/2020-00]. AS was supported by a postdoctoral grant “Juan Rodés” (JE18/00022) from Instituto de Salud Carlos III through the Ministry of Economy and Competitiveness, Spain
Genetic comparison of sickle cell anaemia cohorts from Brazil and the United States reveals high levels of divergence
Genetic analysis of admixed populations raises special concerns with regard to study design and data processing, particularly to avoid population stratification biases. The point mutation responsible for sickle cell anaemia codes for a variant hemoglobin, sickle hemoglobin or HbS, whose presence drives the pathophysiology of disease. Here we propose to explore ancestry and population structure in a genome-wide study with particular emphasis on chromosome 11 in two SCA admixed cohorts obtained from urban populations of Brazil (Pernambuco and Sao Paulo) and the United States (Pennsylvania). Ancestry inference showed different proportions of European, African and American backgrounds in the composition of our samples. Brazilians were more admixed, had a lower African background (43% vs. 78% on the genomic level and 44% vs. 76% on chromosome 11) and presented a signature of positive selection and Iberian introgression in the HbS region, driving a high differentiation of this locus between the two cohorts. The genetic structures of the SCA cohorts from Brazil and US differ considerably on the genome-wide, chromosome 11 and HbS mutation locus levels9CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP8367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-48367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-42008/57441-0; 2014/00984-3; 2012/06438-5; 2015/13152-9; 2008/10596-
Fishers and groupers (epinephelus marginatus and E. morio) in the coast of Brazil : integrating information for conservation
Groupers are a vulnerable but economically important group of fish, especially for small-scale fisheries. We investigated catches and local ecological knowledge (LEK) of diet, habitat, and past fishing experiences. Landings, prices, interviews, and restaurants demand for two species, Epinephelus marginatus (dusky grouper) and Epinephelus morio (red grouper), were registered. We visited 74 markets and 79 sites on the coast of Brazil in 2017–2018, and we interviewed 71 fishers: Bahia (NE), Rio de Janeiro and São Paulo (SE), and Santa Catarina (S). The landings sampled of dusky grouper (2016–2017) in Rio de Janeiro were: n = 222, size 38–109 cm, weight 1–24 kg, average 3.84 kg; in São Paulo, São Sebastião were: n = 47, size 39–106 cm, weight 2–8 kg, average of 2.77 kg; and at Santos: n = 80, 26–120 cm, weight 0.36–15 kg, average 2.72 kg. Red grouper was observed in markets in the northeastern Brazil. We did not observe Epinephelus marginatus from Bahia northward; a maximum size of 200 cm was reported south of the Bahia, besides Rio de Janeiro and São Paulo coasts, 20 years ago (or longer) by 12 fishers. Local knowledge of fishers was important for grouper data of habitat and diet; the reproduction period was identified by fishers as September to March. Groupers can be considered as a cultural and ecological keystone species. We suggest protective measures: 1) fishing zoning, 2) islands (MPAs) with the surveillance of fishers, 3) late Spring and early Summer as key periods for management (grouper reproduction), 4) studies on grouper larvae, 5) mapping of fishing spots, 6) studies on local knowledge. Collaboration with small-scale fishers and local knowledge could contribute to low-conflict management measures. In that regard, integrative models of management from Latin America, by using local knowledge and citizen science, could produce successful grouper management for Brazilian data-poor fisheries, a contrasting reality to the Mediterranean areas. Finally, the distribution of E. marginatus in Brazil leave us with questions: a) Have dusky groupers disappeared from Bahia because of a decline in the population? b) Was it uncommon in Northeast Brazil? c) Did changes in water temperatures forced a movement southward?151CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP307762/2013–0; 301592/2017–914/16939–7In addition to FAPESP and CNPq, we acknowledge Eduardo Camargo and
Marco Antonio A. G. Araújo for helping with fieldwork in NE Brazil and Mara
Magenta (UNISANTA) for helping us with infrastructure for fish larvae
observation in the laboratory. We are grateful to the fisher-buyers Antonio,
Elenilson and Valdecir. We are also very grateful to Rodrigo Caires, who supported us with taxonomic matter
Granulocyte-Colony Stimulating Factor-Overexpressing Mesenchymal Stem Cells Exhibit Enhanced Immunomodulatory Actions Through the Recruitment of Suppressor Cells in Experimental Chagas Disease Cardiomyopathy
Genetic modification of mesenchymal stem cells (MSCs) is a promising strategy to improve their therapeutic effects. Granulocyte-colony stimulating factor (G-CSF) is a growth factor widely used in the clinical practice with known regenerative and immunomodulatory actions, including the mobilization of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Here we evaluated the therapeutic potential of MSCs overexpressing G-CSF (MSC_G-CSF) in a model of inflammatory cardiomyopathy due to chronic Chagas disease. C57BL/6 mice were treated with wild-type MSCs, MSC_G-CSF, or vehicle (saline) 6 months after infection with Trypanosoma cruzi. Transplantation of MSC_G-CSF caused an increase in the number of circulating leukocytes compared to wild-type MSCs. Moreover, G-CSF overexpression caused an increase in migration capacity of MSCs to the hearts of infected mice. Transplantation of either MSCs or MSC_G-CSF improved exercise capacity, when compared to saline-treated chagasic mice. MSC_G-CSF mice, however, were more potent than MSCs in reducing the number of infiltrating leukocytes and fibrosis in the heart. Similarly, MSC_G-CSF-treated mice presented significantly lower levels of inflammatory mediators, such as IFNγ, TNFα, and Tbet, with increased IL-10 production. A marked increase in the percentage of Tregs and MDSCs in the hearts of infected mice was seen after administration of MSC_G-CSF, but not MSCs. Moreover, Tregs were positive for IL-10 in the hearts of T. cruzi-infected mice. In vitro analysis showed that recombinant hG-CSF and conditioned medium of MSC_G-CSF, but not wild-type MSCs, induce chemoattraction of MDSCs in a transwell assay. Finally, MDSCs purified from hearts of MSC_G-CSF transplanted mice inhibited the proliferation of activated splenocytes in a co-culture assay. Our results demonstrate that G-CSF overexpression by MSCs potentiates their immunomodulatory effects in our model of Chagas disease and suggest that mobilization of suppressor cell populations such as Tregs and MDSCs as a promising strategy for the treatment of chronic Chagas disease. Finally, our results reinforce the therapeutic potential of genetic modification of MSCs, aiming at increasing their paracrine actions
Concepções de um grupo de alunos do ensino médio de uma escola pública do município Nova Floresta/PB sobre reações químicas
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Self-reported arm and shoulder problems in breast cancer survivors in Sub-Saharan Africa: the African Breast Cancer-Disparities in Outcomes cohort study
BACKGROUND: Arm and shoulder problems (ASP), including lymphedema, were common among women with breast cancer in high-income countries before sentinel lymph node biopsy became the standard of care. Although ASP impair quality of life, as they affect daily life activities, their frequency and determinants in Sub-Saharan Africa remain unclear. METHODS: All women newly diagnosed with breast cancer at the Namibian, Ugandan, Nigerian, and Zambian sites of the African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort study were included. At each 3-month follow-up interview, women answered the EORTC-QLQ-Br23 questionnaire, including three ASP items: shoulder/arm pain, arm stiffness, and arm/hand swelling. We estimated the cumulative incidence of first self-reported ASP, overall and stratified by study and treatment status, with deaths treated as competing events. To identify determinants of ASP, we estimated cause-specific hazard ratios using Cox models stratified by study site. RESULTS: Among 1476 women, up to 4 years after diagnosis, 43% (95% CI 40-46), 36% (33-38) and 23% (20-25), respectively, self-reported having experienced arm/shoulder pain, stiffness and arm/hand swelling at least once. Although risks of self-reported ASP differed between sites, a more advanced breast cancer stage at diagnosis, having a lower socioeconomic position and receiving treatment increased the risk of reporting an ASP. CONCLUSION: ASP are very common in breast cancer survivors in Sub-Saharan Africa. They are influenced by different factors than those observed in high-income countries. There is a need to raise awareness and improve management of ASP within the African setting
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