Contribuição da agricultura familiar na construção do conhecimento agroecológico: estudo de caso do projeto raízes da terra.

A agricultura itinerante, caracterizada pelo uso do fogo como preparo de area, tem causado consequencias negativas para a agricultura familiar, resultando em grandes areas desflorestadas com baixa produtividade e diminuicao da capacidade regenerativa da vegetacao secundaria. A busca de alternativas sustentaveis a agricultura de derruba e queima baseada em principios agroecologicos pode resultar no desenvolvimento de um meio rural mais sustentavel. Experiencias veem sendo testadas por agricultores familiares atraves do Projeto Raizes da Terra, nesse sentido este trabalho tem como principal objetivo avaliar a contribuicao dos agricultores familiares na construcao do conhecimento agroecologico nos Municipios de Igarape Acu e Marapanim, identificando as razoes que tem levado a incorporação de princípios agroecologicos no manejo do agroecossistema. Para isso, foram avaliados os processos metodologicos e as ferramentas participativas experimentadas pelos agricultores familiares para introducao de um conjunto de praticas agroecologicas em seus sistemas de uso da terra que se mostram promissoras para melhorar a sustentabilidade dos agroecossistemas. O uso do fogo foi reduzido de 28,5ha observado em 2005 para apenas 2ha em 2011, a diversificacao da producao teve um aumento de 51% quando comparado o período de 2005 a 2011 com a implantacao de 42ha de sistemas agroflorestais multiestratificados no periodo de 2006 a 2007 e ampliacao para 55ha em 2011, representado 13ha a mais do planejado pelo projeto Raizes da Terra. Concluindo-se que o processo de construcao do conhecimento agroecologico praticado pelos agricultores familiares do projeto Raizes da Terra contribuiu para o desenvolvimento de uma agricultura de base agroecologica

Nanoscale-length control of the flagellar driveshaft requires hitting the tethered outer membrane

The bacterial flagellum exemplifies a system where even small deviations from the highly regulated flagellar assembly process can abolish motility and cause negative physiological outcomes. Consequently, bacteria have evolved elegant and robust regulatory mechanisms to ensure that flagellar morphogenesis follows a defined path, with each component self-assembling to predetermined dimensions. The flagellar rod acts as a driveshaft to transmit torque from the cytoplasmic rotor to the external filament. The rod self-assembles to a defined length of ~25 nanometers. Here, we provide evidence that rod length is limited by the width of the periplasmic space between the inner and outer membranes. The length of Braun's lipoprotein determines periplasmic width by tethering the outer membrane to the peptidoglycan layer

Giant flagellins form thick flagellar filaments in two species of marine γ-proteobacteria

Flagella, the primary means of motility in bacteria, are helical filaments that function as microscopic propellers composed of thousands of copies of the protein flagellin. Here, we show that many bacteria encode “giant” flagellins, greater than a thousand amino acids in length, and that two species that encode giant flagellins, the marine γ-proteobacteria Bermanella marisrubri and Oleibacter marinus, produce monopolar flagellar filaments considerably thicker than filaments composed of shorter flagellin monomers. We confirm that the flagellum from B. marisrubri is built from its giant flagellin. Phylogenetic analysis reveals that the mechanism of evolution of giant flagellins has followed a stepwise process involving an internal domain duplication followed by insertion of an additional novel insert. This work illustrates how “the” bacterial flagellum should not be seen as a single, idealised structure, but as a continuum of evolved machines adapted to a range of niches

EDUCAÇÃO A DISTÂNCIA NO BRASIL: uma análise da experiência da UFMA do Maranhão

O objetivo do artigo é apresentar os resultados de pesquisa direcionada a avaliar o processo de implementação da Política da Educação a Distância (EAD) no Ensino Superior, tendo como referência empírica a experiência do Núcleo de Educação a Distância (Nead) da UFMA nos municípios de São Luís e Humberto de Campos, com vistas a identificar a interferência de diferentes contextos socioeconômicos, culturais, políticos e institucionais na dinâmica de tal processo. Adota-se o método crítico dialético para apreender a EAD como fenômeno inserido na totalidade da sociedade capitalista contemporânea. Desenvolve-se uma pesquisa avaliativa tendo como objeto o processo de implementação da referida política, a partir da experiência dos municípios selecionados. Além de pesquisa bibliográfica, documental e análise de dados secundários adota-se como procedimentos metodológicos, na pesquisa empírica.Palavras-chave: Estado. Capital. Educação a Distância. Educação Superior. Universidade Federal do Maranhão.DISTANCE EDUCATION IN BRAZIL: a study about the experience of the Federal University of MaranhãoAbstractThe objective of the article is to present the results of the research directed to evaluate the process of implementation of the D.E Policy in Higher Education, having as an empirical reference the experience of the Distance Education Center (NEAD) - UFMA in the municipalities of São Luis and Humberto de Campos, with a view to identify the interference of different socioeconomic, cultural, political and institutional contexts in the dynamics of this process. The dialectical critical method is adopted to apprehend D.E as a phenomenon inserted in the broader of contemporary capitalist society. An evaluative research is developed having as object the process of implementation of the referred policy, from the experience of the selected municipalities. In addition to bibliographic, documentary and secondary data analysis, it is adopted the following methodological procedures in empirical research such as: focus groups involving policy beneficiaries and semi-structured interviews with managers, teachers and tutors of Nead and the studied poles.Keywords: State. Capital. Distance Education. Higher Education. Federal University of Maranhão

The malaria parasite chaperonin containing TCP-1 (CCT) complex: Data integration with other CCT proteomes

The multi-subunit chaperonin containing TCP-1 (CCT) is an essential molecular chaperone that functions in the folding of key cellular proteins. This paper reviews the interactome of the eukaryotic chaperonin CCT and its primary clients, the ubiquitous cytoskeletal proteins, actin and tubulin. CCT interacts with other nascent proteins, especially the WD40 propeller proteins, and also assists in the assembly of several protein complexes. A new proteomic dataset is presented for CCT purified from the human malarial parasite, P. falciparum (PfCCT). The CCT8 subunit gene was C-terminally FLAG-tagged using Selection Linked Integration (SLI) and CCT complexes were extracted from infected human erythrocyte cultures synchronized for maximum expression levels of CCT at the trophozoite stage of the parasite’s asexual life cycle. We analyze the new PfCCT proteome and incorporate it into our existing model of the CCT system, supported by accumulated data from biochemical and cell biological experiments in many eukaryotic species. Together with measurements of CCT mRNA, CCT protein subunit copy number and the post-translational and chemical modifications of the CCT subunits themselves, a cumulative picture is emerging of an essential molecular chaperone system sitting at the heart of eukaryotic cell growth control and cell cycle regulation

Realidade virtual na função motora de membros inferiores pós-acidente vascular encefálico

O Acidente Vascular Encefálico (AVE) pode gerar importantes alterações motoras, de tônus e sensitivas. A realidade virtual (RV), voltada para reabilitação, pode trazer benefícios em relação à aptidão física, atividades motoras e de equilíbrio. Objetivo: Investigar o efeito da terapia por RV no equilíbrio estático e dinâmico, descarga de peso no membro inferior afetado, tônus e recrutamento muscular, independência funcional e função sensório-motora de indivíduos pós-AVE. Métodos: Trata-se de estudo clínico, quasi-experimental e prospectivo em 6 indivíduos com diagnóstico de AVE. Antes e após intervenção com Nintendo Wii Fit Plus os indivíduos foram avaliados pela Escala de Equilíbrio de Berg, Timed “Up and Go”, Índice do Andar Dinâmico; Teste de Marcha (TM); Escala Modificada de Ashworth (EMA); Eletromiografia; Índice de Barthel e Escala Fugl Meyer (EFM). Para análise estatística utilizou-se o teste Kolmogorov-Smirnov, teste t e Wilcoxon. Foi adotado P 80%. Resultados: No TM inicial da 1ª e 15ª sessão (p = 0,03; d = 1,96; P = 96%), EMA dos músculos extensores de quadril (p = 0,04; d = 3,77; P 99%) e joelho (p = 0,04; d = 3,23; P = 99%) e flexores plantares (p = 0,01; d = 3,18; P = 99%) e EFM nas dimensões coordenação/velocidade (p = 0,02; d = 6,74; P = 100%) e sensibilidade (p = 0,01), foram observados resultados significativos com grande efeito e Power > 90%. Nos demais instrumentos não foram encontrados valores significativos. Conclusão: O programa de reabilitação, por RV, foi eficaz na melhora da descarga de peso no membro inferior afetado, tônus muscular e função sensório-motora nos indivíduos do estudoStrokes can generate significant motor, tonic and sensitive changes. Virtual reality (RV), focused on rehabilitation, can bring several benefits such as improvements on physical fitness, motor skills and balance. Objective: To assess the effects of the RV intervention to the static and dynamic balance, weight load on the affected limb, tone and muscle recruitment, functional independence and sensorimotor function in post-stroke individuals. Methods: Quasi-experimental and prospective clinical study with 6 subjects with diagnosis of stroke. Before and after the intervention with Nintendo Wii Fit Plus, the subjects were assessed by the Berg Balance Scale, Timed “Up and Go” and Dynamic Floor Index; Gait Test (GT); Modified Ashworth Scale (MAS); Electromyography; Barthel Index and Fugl-Meyer Scale (FMS). The Statistical analysis used Kolmogorov-Smirnov test, t test and Wilcoxon. Results: The 1st and 15th session evaluations have shown that GT (p = 0.03, d = 1.96, P = 96%), MAS for hip extensor muscles (p = 0.04; d = 3.77; P = 99%), knee extensors (p = 0.04; d = 3.23; P = 99%), plantar flexors (p = 0.01; d = 3.18; P = 99%), FMS in coordination/velocity dimensions (p = 0.02; d = 6.74; P = 100%) and sensitivity (p = 0.01) presented significant results, large effect size and power above 90%. Significant values were not found to the other evaluations. Conclusion: The RV rehabilitation program was effective and improved the weight-load in affected limb, muscle tone and sensorimotor function of the subject

A MULHER NA CIÊNCIA: UM BREVE HISTÓRICO E REFLEXÕES SOBRE POLÍTICAS E AMBIENTE LABORAL

O presente texto tem por objetivo apresentar um breve histórico da luta das mulheres numa seara tão difícil como é o ambiente laboral na Ciência. Algumas lutas e nomes serão explorados, bem como algumas questões legais ligadas ao tema do protagonismo feminino. O aumento desse protagonismo também será discutido, além da discussão dos espaços sociais dicotomizados e naturalizados por um raciocínio masculino que impactam especialmente as áreas da Física e das Engenharias. É ressaltado o fato de que as mulheres na esfera da ciência não são desobrigadas de suas responsabilidades como mães, com os cuidados da casa, persistindo aí uma divisão sexual do trabalho gerando uma jornada excessiva, o que acaba por desestimular o protagonismo necessário que vem ocorrendo, mas ainda desprovido de políticas públicas que o suporte e o catapulte para um patamar superior aos níveis atuais do mercado de trabalho. É necessário, pois, tomar como ponto de partida a continuação e o aprofundamento do debate quanto ao papel das mulheres no Direito do Trabalho, na Ciência e nos ambientes trabalhistas em geral

Trophic consequences of non-native pumpkinseed Lepomis gibbosus for native pond fishes

Introduced non-native fishes can cause considerable adverse impacts on freshwater ecosystems. The pumpkinseed Lepomis gibbosus, a North American centrarchid, is one of the most widely distributed non-native fishes in Europe, having established self-sustaining populations in at least 28 countries, including the U.K. where it is predicted to become invasive under warmer climate conditions. To predict the consequences of increased invasiveness, a field experiment was completed over a summer period using a Control comprising of an assemblage of native fishes of known starting abundance and a Treatment using the same assemblage but with elevated L. gibbosus densities. The trophic consequences of L. gibbosus invasion were assessed with stable isotope analysis and associated metrics including the isotopic niche, measured as standard ellipse area. The isotopic niches of native gudgeon Gobio gobio and roach Rutilus rutilus overlapped substantially with that of non-native L. gibbosus, and were also substantially reduced in size compared to ponds where L. gibbosus were absent. This suggests these native fishes shifted to a more specialized diet in L. gibbosus presence. Both of these native fishes also demonstrated a concomitant and significant reduction in their trophic position in L. gibbosus presence, with a significant decrease also evident in the somatic growth rate and body condition of G. gobio. Thus, there were marked changes detected in the isotopic ecology and growth rates of the native fish in the presence of non-native L. gibbosus. The implications of these results for present and future invaded pond communities are discussed

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Structural investigation of the evolution, mechanism and assembly of the flagellar motor

The evolution of molecular machines is fundamental to the development of pathogenesis in bacteria. This drives the adaptation to new lifestyles and the colonisation of novel niches. One such machine is the bacterial flagellum, an extracellular motility device which enables cells to actively seek out favourable environments. The flagellum is a vital virulence factor in many bacteria including the important human pathogen, Salmonella enterica. Studying the evolution, mechanism, assembly and regulation of the flagellum will shed light on how modifications in this large molecular machine facilitate life in different environments. At the base of the flagellum is the flagellar motor, which converts electrochemical potential, via the stator complexes, into torque. Torque is then transmitted up the periplasmic rod to rotate the extracellular hook, and filament. The -proteobacterium, Salmonella, has a highly dynamic flagellar motor, perfectly poised for encountering different environments. Surprisingly, this gut pathogen has evolved a different mode of swimming and an environmental niche which is distinct from its close aquatic relatives. Here, using a combination of techniques, I studied the flagellar motor in situ and show that Salmonella’s motor is not native but is a -proteobacterial motor acquired from an ancestor of Bordetella. This new, adaptive motor may have provided a selective advantage to enable Salmonella’s enteropathogenic lifestyle. Interestingly, the non-enteric, -proteobacteria that retained native -motors, swim faster than Salmonella but fare poorly in low nutrient environments. I show that these bacteria have a distinct mechanism for down regulation of motility, for entry into a sessile state. These cells eject their flagella in nutrient limited environments and actively plug the partial structure that is left behind in the outer membrane. I next work towards providing a more detailed understanding of the dynamic mechanism of stator complex incorporation, and finally, provide a novel mechanism for the regulation of rod length. Together, enabled by recent technological advances in the field of electron cryotomography, this work provides insight into some of the fundamental outstanding questions into the evolution, mechanism and regulation of the flagellum.Open Acces