955 research outputs found

    The orchid bees (Hymenoptera, Apidae, Euglossina) in a forest fragment from western Paraná state, Brazil

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    An orchid bee inventory was carried out in Parque Estadual São Camilo, Palotina, Paraná (Brazil); conservation unit with about 400 hectares of Semidecidual Seasonal forest. Three bait traps were installed at the border of the fragment, each one containing the following fragrances: 1,8-cineole, eugenol, and vanilin. Sampling was carried out from 09am to 03pm, October 2011 to June 2012, summing up nine sampling days. A total of 186 specimens distributed among seven species were sampled. Eufriesea violacea with 140 specimens was the most common species, followed by Euglossa fimbriata (31), Euglossa annectans (9), Eulaema nigrita (4), Euglossa cordata (1), Euglossa pleosticta (1), and Exaerete smaragdina (1). According to qualitative and NMDS analysis, the orchid bee fauna of Parque Estadual São Camilo is representative of Semidecidual Seasonal forest, with richness comparable with other assemblages in the southern distribution of Euglossina. The sampled bee richness indicates that forest fragments, even small and isolated, are important in the conservation of this bees.Abelhas das orquídeas (Hymenoptera, Apidae, Euglossina) em um fragmento florestal do oeste do Paraná. Um inventário de abelhas das orquídeas foi conduzido no Parque Estadual São Camilo, Palotina, Paraná, uma unidade de conservação de cerca de 400 hectares de Floresta Estacional Semidecidual. Três garrafas-armadilha foram instaladas na borda do fragmento, cada uma contendo uma das seguintes essências: 1,8-cineol, eugenol e vanilina. A amostragem foi realizada entre 09 e 15 horas, entre outubro de 2011 e junho de 2012, somando nove dias amostrais. Um total de 186 espécimens distribuídos em sete espécies foram amostrados, Eufriesea violacea com 140 indivíduos foi a mais comum, seguida de Euglossa fimbriata com 31, Euglossa annectans com nove, Eulaema nigrita com quatro, Euglossa cordata, Euglossa pleosticta e Exaerete smaragdina com apenas um indivíduo amostrado cada. De acordo com análise qualitativa e de NMDS a fauna de Euglossina de Parque Estadual São Camilo é representativa de Floresta Estacional Semidecidual, com riqueza comparável a outras áreas no sul da distribuição do grupo. A riqueza de espécie amostrada indica que fragmentos florestais, mesmo que pequenos e isolados, são importantes na conservação destas abelhas

    Investigando o Efeito Leidenfrost: um relato de uma atividade exploratória em dois contextos educativos

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    Autores defendem que alguns dos objetivos do ensino de ciências atualmente são o desenvolvimento do pensamento crítico dos alunos; produção de reflexões e de conhecimento e construção da autonomia para a tomada de decisões cientificamente informadas. Isso envolve problematizar os modelos científicos e estudar os seus contextos e processos de produção. Por esse motivo, é fundamental familiarizar os estudantes com os processos de avaliação e crítica pelos quais se constitui a ciência. Com este objetivo, o presente trabalho traz o relato de uma atividade exploratória proposta a alunos de duas escolas do Rio de Janeiro, tendo como tema o efeito Leidenfrost. As respostas dos alunos foram organizadas em categorias a partir das quais são traçadas possibilidades para o trabalho do professor em sala de aula e delineadas tendências aparentes nos dois contextos educacionais

    Natural based reusable materials for microfluidic substrates: The silk road towards sustainable portable analytical systems

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    Portable analytical systems are versatile tools for application in areas including biomedicine, biosecurity, food safety and environmental monitoring. This work contributes to the increasing demand for low-cost, environmentally friendly substrates for portable analytical systems by using natural Bombyx mori cocoons. Further, silk fibroin is also extracted from these cocoons and electrospun into oriented and randomly oriented fiber substrates. Oxygen plasma treatment is applied to improve their hydrophilicity. Fiber morphology, mechanical properties, porosity, thermal characteristics and surface contact angle are extensively characterized and the ability of the samples for passive capillary flows demonstrated. Plasma treated pressed cocoons show superhydrophilicity, capillary flow rates of 44.8 ± 3.75 mm.min-1, and high mechanical resistance with Young's modulus values up to 592.13 ± 19.83 MPa. The developed materials are used as substrates for the colorimetric quantification of three commonly scrutinized clinical analytes. Hydrophobic barriers are first wax-printed on all samples with a proper design and albumin assays are performed on all substrates. Further assays for uric acid and glucose quantification are successfully accomplished on the pressed cocoons after a simple in between washing step, with overall high coefficient of determination, proving the suitability of the developed materials as low-cost, sustainable and reusable microfluidic substrates.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under strategic funding UID/FIS/04650/2020, UIDB/04436/2020, UIDP/04436/2020 and project PTDC/EMD-EMD/28159/2017 (POCI-01–0145-FEDER-028159). The authors also thank FCT for financial support under grants SFRH/BD/140698/2018 (R.B. P.), 2020.09218.BD (A.S.M.), 2020.04163.CEECIND (C.R.) and 2020.02304.CEECIND (V.F.C.). Finally, the authors acknowledge fund ing by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019–106099RB C43/AEI/10.13039/501100011033 and from the Basque Government Industry Departments under the ELKARTEK program. Finally, the au thors also thank Dr. J. Borges and Prof. F. Vaz for experimental support.info:eu-repo/semantics/publishedVersio

    N′-[3-(Hy­droxy­imino)­butan-2-yl­idene]-4-methyl­benzene-1-sulfono­hydrazide

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    In the title compound, C11H15N3O3S, the C—S—N(H)—N linkage is nonplanar, the torsion angle being 75.70 (12)°. The compound has two almost planar fragments linked to the S atom: the hydrazone-derivative fragment [(HONC4H6)N—N(H)–] and the tolyl fragment (C7H7–) have maximum deviations from the mean plane through the non-H atoms of 0.0260 (10) and 0.0148 (14) Å, respectively. The two planar fragments make an inter­planar angle of 79.47 (5)°. In the crystal, mol­ecules are connected through inversion centers via pairs of N—H⋯O and O—H⋯N hydrogen bonds

    Assessment of data on vector and host competence for Japanese encephalitis virus: A systematic review update of Oliveira et al. 2018

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    Japanese Encephalitis (JE) is an emerging, zoonotic disease transmitted primarily by Culex species mosquitoes (particularly Culex tritaeniorhynchus) carrying the flavivirus Japanese encephalitis virus (JEV). Japanese encephalitis virus maintains its life cycle between mosquitoes and vertebrate hosts, primarily pigs and wading birds (Le Flohic et al., 2013). JE is an untreatable and incurable disease that, in humans, can result in inflammation of the brain (encephalitis) causing fever, headache, respiratory signs, gastrointestinal signs, confusion, seizures, coma, and, in some cases, death (Fischer et al., 2012; Kliegman et al., 2015). The United States (US) is considered a susceptible region with great potential for JEV introduction, given the availability of competent insect vectors, susceptible maintenance (avian) hosts, large populations of susceptible, amplifying hosts (domestic and feral pigs), intensive travel and trade activities to and from JEV-affected countries, and areas with similar climatic and environmental conditions to countries where the virus is epidemic. To investigate the risk of JEV introduction and establishment, Oliveira and colleagues performed a risk assessment (Oliveira et al., 2019) supported by a systematic review of vector and host competency for JEV (Oliveira et al., 2018). 3Although Oliveira et al. (2019) found the risk of introduction of JEV in the US through entry of infected mosquitoes via airplanes to be very high, the risk of establishment was considered negligible; yet, increases in international trade and globalization, as well as changes in climate and land use, and the recent incursion of a new JEV genotype into areas previously free from disease, as observed in Australia with the invasion and expansion of JEV (Genotype IV) in the eastern and southeastern states, warrants the need for an update of the review and risk assessment. The objective of this review is to update the systematic review (Oliveira et al., 2018) on host and vector competence of transmission of the Japanese encephalitis virus

    Can functional exercise capacity discriminate older individuals with poor postural control?

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    Postural instability can be related to functional limitations as a result of the aging process. This study aimed to compare functional exercise capacity and postural control in older adults. Participants were allocated into three groups according to their functional exercise capacity based on the six minute walking test (6MWT): 1) Low performance group (LP: distance walked ≤ 80% of the predicted value n = 19), 2) Normal performance group (NP: distance walked 81-100% of the predicted value n = 21) and, 3) High performance group (HP: distance walked >100% of the predicted value n = 23). All groups performed three trials of a one-leg stance for 30s on a force platform. LP showed worse postural control in comparison to NP and HP, and significant differences (p < .05) were found between groups for area, velocity antero-posterior of center of pressure and time limit variables during the one-leg stance task. These results have implications for rehabilitation management with regard to exercise, balance assessment and intervention in older adults. Instabilidade postural pode estar relacionada com as limitações funcionais, como um resultado do processo de envelhecimento. Este estudo teve como objetivo comparar a capacidade funcional de exercício e o controle postural em indivíduos idosos. Os participantes foram separados em três grupos de acordo com sua capacidade funcional de exercício baseada no teste de caminhada de seis minutos (TC6min): 1) grupo baixo desempenho (BD: distância caminhada ≤ 80% do valor predito n = 19), 2) grupo normal desempenho (ND : distância caminhada 81-100% do valor predito n = 21) e, 3) grupo alto desempenho (AD: distância caminhada >100% do valor predito n = 23). Todos os grupos realizaram três testes com apoio unipodal permanecendo por 30s sobre a plataforma de força. BD apresentou pior equilíbrio postural em comparação com ND e AD; com diferenças significativas (p < 0,05) encontradas entre os grupos para os parâmetros de área e velocidade antero-posterior do centro de pressão e a variável tempo-limite durante a posição unipodal. Estes resultados têm implicações para estratégias de reabilitação no que diz respeito ao exercício, avaliação do equilíbrio e intervenção em idosos. Inestabilidad postural puede estar relacionada con las limitaciones funcionales como resultado del proceso de envejecimiento. Este estudio tuvo como objetivo evaluar la comparación entre la capacidad funcional del ejercicio en el control postural de las personas de edad avanzada. Los participantes fueron divididos en tres grupos de acuerdo a su capacidad de ejercicio funcional basado en la Prueba de Caminada de seis minutos (PC6M): 1) grupo Bajo Rendimiento (BR: distancia recorrida ≤ 80% del valor predijo, n = 19), 2) grupo Normal Rendimiento (NR: distancia recorrida 81-100% del valor predijo, n = 21) y 3) grupo Alto Rendimiento (AR: distancia recorrida >100% del valor predijo, n = 23). Todos los grupos realizaron tres pruebas sobre un solo pie por 30s en la plataforma de fuerza. BR presentó un mal equilibrio postural en comparación con NR y AR; con diferencias significativas (p < 0,05) encontrado entre los grupos de los parámetros área y velocidad antero-posterior del centro de presión y el límite de tiempo para la postura de una sola pierna. Estos resultados tienen implicaciones para las estrategias de rehabilitación en relación con el ejercicio, la evaluación del equilibrio y la intervención en los ancianos

    Differences and similarities of postprandial lipemia in rodents and humans

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    The rat has been a mainstay of physiological and metabolic research, and more recently mice. This study aimed at characterizing the postprandial triglyceride profile of two members of the Muridae family: the Wistar rats (Rattus norvegicus albinus) and C57BL/6 mice (Mus musculus) plus comparing them to the profile obtained in humans. Thirty-one male and twelve female Wistar rats, ten C57BL/6 male and nine female mice received a liquid meal containing fat (17%), protein (4%) and carbohydrates (4%), providing 2 g fat/Kg. Thirty-one men and twenty-nine women received a standardized liquid meal containing fat (25%), dextromaltose (55%), protein (14%), and vitamins and minerals (6%), and providing 40 g of fat per square meter of body surface. Serial blood samples were collected at 2, 4, 6, 8 and 10 h after the ingestion in rats, at 1, 2, 3, 4, 5 and 6 h in mice and in humans at 2, 4, 6 and 8 h. Wilcoxon and Mann-Whitney tests were used. The triglyceride responses were evaluated after the oral fat loads. Fasting and postprandial triglyceridemia were determined sequentially in blood sample. AUC, AUIC, AR, RR and late peaks were determined. Rats are prone to respond in a pro-atherogenic manner. The responses in mice were closer to the ones in healthy men. This study presents striking differences in postprandial triglycerides patterns between rats and mice not correlated to baseline triglycerides, the animal baseline body weight or fat load in all animal groups.101CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão te

    Correlation between LTR point mutations and proviral load levels among Human T cell Lymphotropic Virus type 1 (HTLV-1) asymptomatic carriers

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    <p>Abstract</p> <p>Background</p> <p>In vitro studies have demonstrated that deletions and point mutations introduced into each 21 bp imperfect repeat of <it>Tax</it>-responsive element (TRE) of the genuine human T-cell leukemia virus type I (HTLV-1) viral promoter abolishes <it>Tax </it>induction. Given these data, we hypothesized that similar mutations may affect the proliferation of HTLV-1i</p> <p>nfected cells and alter the proviral load (PvL). To test this hypothesis, we conducted a cross-sectional genetic analysis to compare the near-complete LTR nucleotide sequences that cover the TRE1 region in a sample of HTLV-1 asymptomatic carriers with different PvL burden.</p> <p>Methods</p> <p>A total of 94 asymptomatic HTLV-1 carriers with both sequence from the 5' long terminal repeat (LTR) and a PvL for <it>Tax </it>DNA measured using a sensitive SYBR Green real-time PCR were studied. The 94 subjects were divided into three groups based on PvL measurement: 31 low, 29 intermediate, and 34 high. In addition, each group was compared based on sex, age, and viral genotypes. In another analysis, the median PvLs between individuals infected with mutant and wild-type viruses were compared.</p> <p>Results</p> <p>Using a categorical analysis, a G232A substitution, located in domain A of the TRE-1 motif, was detected in 38.7% (12/31), 27.5% (8/29), and 61.8% (21/34) of subjects with low, intermediate, or high PvLs, respectively. A significant difference in the detection of this mutation was found between subjects with a high or low PvL and between those with a high or intermediate PvL (both <it>p </it>< 0.05), but not between subjects with a low or intermediate PvL (<it>p </it>> 0.05). This result was confirmed by a non-parametric analysis that showed strong evidence for higher PvLs among HTLV-1 positive individuals with the G232A mutation than those without this mutation (<it>p </it>< 0.03). No significant difference was found between the groups in relation to age, sex or viral subtypes (<it>p</it> > 0. 05).</p> <p>Conclusions</p> <p>The data described here show that changes in domain A of the HTLV-1 TRE-1 motif resulting in the G232A mutation may increase HTLV-1 replication in a majority of infected subjects.</p

    Clinical correlates of plasma insulin levels over the life course and association with incident type 2 diabetes: the Framingham Heart Study

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    Introduction Insulin is a glucose-lowering hormone that affects carbohydrate, lipid, and protein metabolism. Limited data exist on the correlates of insulin levels over the life course in healthy community-dwelling individuals. Research design and methods Using multilevel modeling of multiple serial observations over 21 years, we assessed the longitudinal correlates of fasting insulin and the cross-sectional correlates of fasting and 2-hour (2h, post 75 g glucose challenge) plasma insulin concentrations in 2140 relatively healthy Framingham Heart Study participants without diabetes (61% women; mean age, 42 years). We used multivariable-adjusted Cox regression to relate glycemic markers (fasting and 2h-insulin, fasting glucose, 2h-glucose, and hemoglobin A1C) to the risk of type 2 diabetes during follow-up. Results Over the life course, fasting insulin concentrations were inversely associated with age, male sex, and physical activity, whereas waist circumference, the total/high-density lipoprotein (HDL) cholesterol ratio, and blood triglycerides were positively associated with insulin levels (p<0.005 for all). Male sex (inversely related) and the total/HDL cholesterol ratio (positively related) emerged as the most important cross-sectional correlates of 2h-insulin (p<0.005 for all). All markers were associated with higher risk of type 2 diabetes (352 cases, median follow-up 18 years, p<0.001 for all). Conclusions We observed common and distinct correlates of fasting and 2h-insulin levels. Our findings highlight a potential role of insulin in lipid and lipoprotein metabolism. Furthermore, fasting and 2h-insulin are critical markers of future diabetes risk. Further studies are needed to confirm our findings
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