276 research outputs found

    Nutrients balance and tip burn incidence in lettuce from hydroponic system – NFT

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    Para avaliar o efeito do balanço nutricional na incidência de queima de bordos em plantas de alface, conduzidas em hidroponia, foi instalado um experimento em área da Universidade de Brasília, de outubro/2001 a junho/2002. Na primeira etapa do experimento, foram adotadas quatro condutividades elétricas (0,5; 1,5; 2,5 e 4,0 mS.cm-1) para avaliar a que apresentaria a maior incidência de queima de bordos. Em uma segunda etapa, adotou-se a concentração de 4,0 mS.cm-1 e aplicações foliares de três fontes de cálcio (CaCl2, CaB2® e CaNO3) com o objetivo de prevenir a ocorrência dos sintomas. Utilizou-se a formulação proposta por Castellane e Araújo em 1995, variando-se a concentração total dos nutrientes para atingir a condutividade elétrica desejada. O delineamento experimental foi em faixas, com quatro tratamentos e três repetições com 25 plantas cada. Foram avaliados a porcentagem de plantas com incidência de queima de bordos, teor foliar de macro e micronutrientes e peso fresco. Utilizou-se o sistema DRIS para análise dos teores foliares de nutrientes. Foi observado que a solução nutritiva de 4 mS.cm-1 apresentou porcentagem de plantas com queima de bordos superior às soluções com concentração de 2,5 e 1,5 mS.cm-1. Porém, não diferiu estatisticamente da solução com 0,5 mS.cm-1. Na segunda etapa, verificou-se que zinco foi o nutriente mais limitante, em função da alta concentração de boro, tendo sido o responsável pela incidência dos sintomas de queima de bordos. Desta forma, as pulverizações com cálcio, independentemente da fonte, não foram eficientes no controle ou redução dos sintomas.Aiming to evaluate the effect of nutrients balance in lettuce tip burn incidence, an experiment was carried out in Brasília, Brazil, from October 2001 until June 2002, in two phases. During the first phase four solution concentrations (0.5; 1.5; 2.5 and 4.0 mS.cm-1) were evaluated to determine the concentration with the highest percentage of tip burn. During the second phase, a solution concentration of 4,0 mS.cm-1 and foliar applications of three calcium sources (CaCl2, CaB2® and CaNO3) were applied to plants to prevent tip burn. Nutritive solution proposed by Castellane and Araújo in 1995 was used in both phases. The evaluated parameters were percentage of plants with tip burn incidence, leaf nutrient concentration and plant fresh weight. In the first trial the more concentrated (4,0 mS.cm-1) and the less concentrated (0,5 mS.cm-1) nutritive solution presented the highest percentage of plants with the symptoms. In the second trial, the zinc deficiency induced by boron high concentration, was responsible for the symptoms. This was the reason why calcium leaf application was not effective on reducing foliar symptoms

    Avaliação das aprendizagens: Representações sociais elaboradas por estudantes de enfermagem

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    A avaliação envolve variáveis de contexto como dinâmicas de sala de aula e estudantes, em particular na forma como influencia os processos de aprendizagem. Estas variáveis emergem como fatores menos estudados (Fernandes, 2009). Com o objetivo de analisar as representações sociais (RS), sobre avaliação das aprendizagens, elaboradas pelos estudantes de enfermagem realizou-se estudo exploratório com 40 participantes. Recolheram-se dados por questionário elaborado para a técnica da evocação livre de palavras. Os dados foram processados nos softwares Evoc e SIMI que forneceram a estrutura e o campo das RS. Os participantes são maioritariamente do sexo feminino, com idade média de 21 anos. A estrutura das RS obtida é: Núcleo central – conhecimentos, estudar e frequências 2ª Periferia – aulas, importante, praticar e professores. Comprovou-se a centralidade do elemento conhecimentos e uma relação forte entre os elementos conhecimentos e avaliações, trabalhos e frequência. A avaliação é entendida como fazendo parte da aprendizagem (Boggino, 2009; Fernandes,2009; Pinto e Santos, 2006). O teste escrito individual é o instrumento de avaliação por excelência quando o foco é categorizar as respostas dadas (Pinto e Santos, 2006). Qualquer avaliação conduz o aluno ao processo de reflexão orientado para o que estudar e como estudar (Carmona e Flores, 2008). A avaliação deve fazer parte duma abordagem coerente que promova o desenvolvimento profissional, a aprendizagem e a qualificação dos estudantes (Boggino, 2009;Looney, 2011). Conclui-se que no universo estudado a avaliação das aprendizagens significa para os estudantes estudar, realizarem provas e adquirirem conhecimentos. A avaliação significa a relação entre o processo de aprendizagem e os resultados do mesmo o que indicia a existência da dualidade que o conceito encerra. Os elementos da representação social com menor consistência referem-se aos processos que fazem parte da formação reforçando o indício da avaliação ser entendida estratégia para a aprendizagem. Há necessidade de desenvolver a investigação e a investigação-ação em projetos relacionados com as técnicas, as estratégias de avaliação e os resultados na aprendizagem

    From cannabinoids and neurosteroids to statins and the ketogenic diet: new therapeutic avenues in Rett syndrome?

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    Copyright © 2019 Mouro, Miranda-Lourenço, Sebastião and Diógenes. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused mainly by mutations in the MECP2 gene, being one of the leading causes of mental disability in females. Mutations in the MECP2 gene are responsible for 95% of the diagnosed RTT cases and the mechanisms through which these mutations relate with symptomatology are still elusive. Children with RTT present a period of apparent normal development followed by a rapid regression in speech and behavior and a progressive deterioration of motor abilities. Epilepsy is one of the most common symptoms in RTT, occurring in 60 to 80% of RTT cases, being associated with worsening of other symptoms. At this point, no cure for RTT is available and there is a pressing need for the discovery of new drug candidates to treat its severe symptoms. However, despite being a rare disease, in the last decade research in RTT has grown exponentially. New and exciting evidence has been gathered and the etiopathogenesis of this complex, severe and untreatable disease is slowly being unfolded. Advances in gene editing techniques have prompted cure-oriented research in RTT. Nonetheless, at this point, finding a cure is a distant reality, highlighting the importance of further investigating the basic pathological mechanisms of this disease. In this review, we focus our attention in some of the newest evidence on RTT clinical and preclinical research, evaluating their impact in RTT symptomatology control, and pinpointing possible directions for future research.FM was in receipt of a fellowship (IMM/CT/8-2018). The authors would like to thank the following organizations for their funding: AdoRett – LISBOA-01-0145-FEDER-031929; the Association Française du Syndrome de Rett Program “Educação pela Ciência” | Bolsas CHLN/FMUL; GAPIC. Project No. 20190017; Twinning action (SynaNet) from the EU H2020 Programme; and the UID/BIM/50005/2019, project financed by the FCT/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES), through the Fundos do Orçamento de Estado.info:eu-repo/semantics/publishedVersio

    Vida depois da morte: narrativas da experiência de perda de um famliar por suicídio

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    Este estudo, de natureza qualitativa e exploratória, pretende conhecer e analisar os significados que as pessoas constroem a partir da experiência de perda, por suicídio, de um familiar (i.e. sobrevivente-familiar). Procura também perceber se os significados diferem entre pessoas com diferentes níveis de sintomatologia psicopatológica. Foram entrevistados oito adultos que perderam familiares por suicídio, há mais de 1 ano e há menos de 10 anos, recrutados por procedimentos de amostragem por conveniência. Para estes sobreviventes, o suicídio do familiar inserese no campo semântico do drama, existindo uma tendência dos indivíduos com maior sintomatologia para a construção de significados autorreferentes de ineficácia. Estes resultados podem constituir-se como indicadores discursivos de risco psicopatológico. Surge também como uma implicação deste estudo a importância de se intervir na redução do estigma social e na promoção de acesso a serviços de apoio psicológico capazes de auxiliar os sobreviventes na construção de significados adaptativos; Abstract: Life after death: Narratives of a family member loss experience by suicide This qualitative and exploratory study aims to know and analyze the meanings that people construct from the loss experience of a family member, by suicide (i.e. relative-survivor). It also intends to understand if meanings differ between people with distinct psychopathological symptomatology levels. Eight adults who had lost relatives by suicide, for longer than 1 year and less than 10 years, were recruited through convenience sampling procedures. For these survivors, the relative suicide inserts into the semantic field of drama, exhisting a tendency of individuals with greater symptomatology to construct meanings self refering of inefficacy. These results may constitute discursive indicators of psychopathological risk. It also arises as an implication of this study a dimension of intervening in reducing social stigma and promoting access to psychological support services who can assist survivors in constructing adaptive meanings

    Neural stem cells and cannabinoids in the spotlight as potential therapy for epilepsy

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    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Epilepsy is one of the most common brain diseases worldwide, having a huge burden in society. The main hallmark of epilepsy is the occurrence of spontaneous recurrent seizures, having a tremendous impact on the lives of the patients and of their relatives. Currently, the therapeutic strategies are mostly based on the use of antiepileptic drugs, and because several types of epilepsies are of unknown origin, a high percentage of patients are resistant to the available pharmacotherapy, continuing to experience seizures overtime. Therefore, the search for new drugs and therapeutic targets is highly important. One key aspect to be targeted is the aberrant adult hippocampal neurogenesis (AHN) derived from Neural Stem Cells (NSCs). Indeed, targeting seizure-induced AHN may reduce recurrent seizures and shed some light on the mechanisms of disease. The endocannabinoid system is a known modulator of AHN, and due to the known endogenous antiepileptic properties, it is an interesting candidate for the generation of new antiepileptic drugs. However, further studies and clinical trials are required to investigate the putative mechanisms by which cannabinoids can be used to treat epilepsy. In this manuscript, we will review how cannabinoid-induced modulation of NSCs may promote neural plasticity and whether these drugs can be used as putative antiepileptic treatment.This work was supported by IF/01227/2015 and UID/BIM/50005/2019, projeto financiado pela Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) através de Fundos do Orçamento de Estado. D.M.L. (PD/BD/141784/2018) and L.R.-R. (PD/BD/150344/2019) were in receipt of a fellowship from FCT. The authors are in hold of a H2020 Twinning Action from EU (EpiEpiNet).info:eu-repo/semantics/publishedVersio

    Level of nitrate in lettuce as a result of fertilization, harvesting time and storage period

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    O experimento foi conduzido na Fazenda Água Limpa, UnB em Brasília, de janeiro a março de 2004, com o objetivo de avaliar o acúmulo de nitrato em alface, cv. Verônica, sob cultivo protegido, em função da adubação, horário de colheita e tempo de armazenamento (8ºC). O delineamento experimental foi de blocos ao acaso, em esquema fatorial 5 x 4 x 4, em quatro repetições. Os cinco tratamentos de adubação foram: 1,5 kg m-2 de cama-de-frango (T1); 3,0 kg m-2 de esterco bovino (T2); mineral, de acordo com a análise química do solo - M (T3); M acrescida de 1,5 kg m-2 de cama-de-frango (T4) e M acrescida de 3,0 kg m-2 de esterco bovino (T5). Os horários de colheita foram 7; 11; 15 e 18 horas, e os períodos de armazenamento foram 0; 3; 5 e 7 dias. Os tratamentos T1 e T4 resultaram em plantas com os maiores teores de nitrato foliar, 1240,12 e 1303,66 mg NaNO3 kg-1, respectivamente; enquanto T2 resultou no menor acúmulo de nitrato, 547,26 mg NaNO3 kg-1. Porém, quando o esterco bovino foi associado ao adubo mineral (T5), ocorreu um aumento de 2,18 vezes no teor de nitrato foliar (1195,25 mg NaNO3 kg-1). Plantas colhidas às 7 horas apresentaram os menores teores de nitrato, sugerindo ser este o melhor horário para colheita da alface no Distrito Federal. O armazenamento proporcionou uma redução de 29,3% no teor de nitrato ao longo de 7 dias. ________________________________________________________________________________ ABSTRACTThe experiment was carried out in Brasilia, Brazil, from January to March 2004, aiming to evaluate the level of nitrate in lettuce, cv. Veronica, as a result of fertilization, harvesting time and storage period (8ºC). We used the ramdomized blocks experimental design in a factorial 5 x 4 x 4, with four replicates. The five fertilization treatments tested were: 1,5 kg m-2 of chicken manure (T1); 3,0 kg m-2 of cattle manure (T2); mineral, as a result of soil chemical analysis - M (T3); M with 1,5 kg m-2 of chicken manure (T4); and M with 3,0 kg m-2 of cattle manure (T5). The harvesting times were 7 and 11 a.m., and 3 and 6 p.m. The storage periods were 0; 3; 5 and 7 days. The treatments T1 and T4 resulted in plants with the highest levels of nitrate, 1240,12 and 1303,66 mg NaNO3 kg-1, respectivelly, while T2 resulted in the lowest nitrate level, 547,26 mg NaNO3 kg-1. However, when cattle manure was added to M (T5), an increase of 2,18 times was observed in the nitrate level (1195,25 mg NaNO3 kg-1). Plants harvested at 7 a.m. showed the lowest levels of nitrate, suggesting that it is the best moment to harvest lettuce in the Distrito Federal region. During the storage period of seven days, nitrate level was reduced by 29,3%

    Microbiological quality and productivity of lettuce under chemical and organic fertilization

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    A contaminação de hortaliças por micro-oganismos patogênicos é uma realidade. Os adubos orgânicos têm sido responsabilizados por algumas contaminações de hortaliças observadas no Brasil. O objetivo deste trabalho foi avaliar a produtividade e a contaminação de alface por Salmonella sp. e coliformes a 45 °C, cultivada sob adubação orgânica. O delineamento experimental foi de blocos ao acaso, com seis tratamentos, em cinco repetições. Os tratamentos foram: T1 - Testemunha (sem adubação); T2 - Adubação química; T3 - Esterco de galinha; T4 - Esterco bovino; T5 - Húmus de minhoca; e T6 - Composto orgânico. As variáveis analisadas foram matéria fresca, matéria seca, macro e micronutrientes e contaminação microbiológica. Foi observada maior obtenção de matéria fresca nas parcelas adubadas com esterco de galinha (543 g), que diferiu estatisticamente da produção observada nos demais tratamentos. Não foi observada diferença estatística significativa entre tratamentos para matéria seca, com exceção da parcela com composto orgânico que apresentou o menor valor (3,7%). Não foi observada contaminação do solo e nem dos adubos orgânicos por esses micro-organismos. Porém, foi observada contaminação da água de irrigação e da alface por coliformes fecais. Existem fortes indícios de que a água de irrigação tenha sido o principal veículo de contaminação.Vegetable contamination with lethal microorganisms is a reality. Organic manure has been considered responsible for vegetable contamination in Brazil. The aim of this research was to evaluate the yield and lettuce contamination by Salmonella sp. and fecal coliforms, at 45 °C, grown under organic fertilization. The experimental design was in randomized blocks composed with 6 treatments in five replicates. The treatments were: T1 - Control (no fertilization); T2 - Chemical fertilization; T3 - Chicken manure; T4 - Cattle manure; T5 - Worm manure, and T6 - Organic compost. Fresh weight, dry matter percentage, macro and micronutrients, and microbiological contamination were recorded. The highest lettuce weight was observed in the parcels fertilized with chicken manure (543 g), which differed statistically from the weights observed in the other treatments. On the other hand, no statistical difference was observed in the dry matter percentage among the different treatments, with the exception of the value observed at the organic compost treatment, which was the lowest (3,7%). The soil and organic manure samples were not contaminated by Salmonella sp. and fecal coliforms. Nevertheless, irrigation water and lettuce samples were contaminated by fecal coliforms. There is strong evidence that irrigation water was the main source of lettuce contamination

    TrkB-ICD Fragment, Originating From BDNF Receptor Cleavage, Is Translocated to Cell Nucleus and Phosphorylates Nuclear and Axonal Proteins

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    The signaling of brain-derived neurotrophic factor (BDNF) has been suggested to be impaired in Alzheimer's disease (AD), which may compromise the function of BDNF upon neuronal activity and survival. Accordingly, decreased levels of BDNF and its tropomyosin-receptor kinase B-full-length (TrkB-FL) have been detected in human brain samples of AD patients. We have previously found that neuronal exposure to amyloid-beta (A beta) peptide, a hallmark of AD, leads to calpain overactivation and subsequent TrkB-FL cleavage leading to decreased levels of TrkB-FL and the generation of two new fragments: a membrane-bound truncated receptor (TrkB-T') and an intracellular fragment (TrkB-ICD). Importantly, we identified this TrkB-FL cleavage and TrkB-ICD presence in human brain samples, which indicates that this molecular mechanism contributes to the loss of BDNF signaling in humans. The exact role of this TrkB-ICD fragment is, however, unknown. Here, we used a human neuroglioma cell line and rat cortical primary neuronal cultures to track TrkB-ICD intracellularly. Our data show that TrkB-ICD is a relatively stable fragment that accumulates in the nucleus over time, through a phosphorylation-dependent process. We also found that TrkB-ICD has tyrosine kinase activity, inducing the phosphorylation of nuclear and axonal proteins. These findings suggest that TrkB-ICD may lead to a dysregulation of the activity of several proteins, including proteins in the nucleus, to where TrkB-ICD migrates. Since TrkB-ICD is formed by A beta peptide-induced cleavage of TrkB-FL, the present data highlights a new mechanism that may have a role in AD pathophysiology.Peer reviewe

    CuMV VLPs Containing the RBM from SARS-CoV-2 Spike Protein Drive Dendritic Cell Activation and Th1 Polarization.

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    Dendritic cells (DCs) are the most specialized and proficient antigen-presenting cells. They bridge innate and adaptive immunity and display a powerful capacity to prime antigen-specific T cells. The interaction of DCs with the receptor-binding domain of the spike (S) protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pivotal step to induce effective immunity against the S protein-based vaccination protocols, as well as the SARS-CoV-2 virus. Herein, we describe the cellular and molecular events triggered by virus-like particles (VLPs) containing the receptor-binding motif from the SARS-CoV-2 spike protein in human monocyte-derived dendritic cells, or, as controls, in the presence of the Toll-like receptors (TLR)3 and TLR7/8 agonists, comprehending the events of dendritic cell maturation and their crosstalk with T cells. The results demonstrated that VLPs boosted the expression of major histocompatibility complex molecules and co-stimulatory receptors of DCs, indicating their maturation. Furthermore, DCs' interaction with VLPs promoted the activation of the NF-kB pathway, a very important intracellular signalling pathway responsible for triggering the expression and secretion of proinflammatory cytokines. Additionally, co-culture of DCs with T cells triggered CD4+ (mainly CD4+Tbet+) and CD8+ T cell proliferation. Our results suggested that VLPs increase cellular immunity, involving DC maturation and T cell polarization towards a type 1 T cells profile. By providing deeper insight into the mechanisms of activation and regulation of the immune system by DCs, these findings will enable the design of effective vaccines against SARS-CoV-2

    Questionário de Qualidade de Vida de Crianças com Paralisia Cerebral (CP Qol-Child): Tradução e Adaptação para Língua Portuguesa

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    AbstractThe aim of this study was to verify the reliability of the Brazilian Portuguese version of the instrument Cerebral Palsy: quality of life questionnaire for children: primary caregiver questionnaire (CP QOLChild: primary caregiver) translated and culturally adapted. Thus, the translation and cultural adaptation of the instrument was made, and then the procedures to verify its reliability were performed. The translated and culturally adapted questionnaire was answered by 30 caregivers of children with cerebral palsy and inter and intra-observer analysis followed. The data allowed the authors to identify an internal consistency rangering from 0.649 to 0.858, intra-observer reliability from 0.625 to 0.809 and inter-observer reliability from 0.498 to 0.903. The analysis suggests that the instrument has acceptable psychometry.ResumoO objetivo deste estudo foi verificar a confiabilidade da versão em português do Brasil do instrumento Cerebral Palsy: quality of life questionnaire for children: primary caregiver questionnaire (CP QOLChild: primary caregiver) traduzido e adaptado culturalmente. Para tanto, foi realizada a tradução e a adaptação cultural do instrumento e a seguir foram realizados os procedimentos para verificar a confiabilidade. O questionário traduzido e adaptado culturalmente foi respondido por 30 cuidadores de crianças com paralisia cerebral e realizada a análise inter e intraobservadores. Os dados permitiram identificar que consistência interna variou de 0,649 a 0,858, a confiabilidade intraobservador de 0,625 a 0,809 e a confiabilidade interobservador 0,498 a 0,903. A análise realizada sugere que o instrumento utilizado tem aceitabilidade psicométrica
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