Origins of the Xylella fastidiosa Prophage-Like Regions and Their Impact in Genome Differentiation

Xylella fastidiosa is a Gram negative plant pathogen causing many economically important diseases, and analyses of completely sequenced X. fastidiosa genome strains allowed the identification of many prophage-like elements and possibly phage remnants, accounting for up to 15% of the genome composition. To better evaluate the recent evolution of the X. fastidiosa chromosome backbone among distinct pathovars, the number and location of prophage-like regions on two finished genomes (9a5c and Temecula1), and in two candidate molecules (Ann1 and Dixon) were assessed. Based on comparative best bidirectional hit analyses, the majority (51%) of the predicted genes in the X. fastidiosa prophage-like regions are related to structural phage genes belonging to the Siphoviridae family. Electron micrograph reveals the existence of putative viral particles with similar morphology to lambda phages in the bacterial cell in planta. Moreover, analysis of microarray data indicates that 9a5c strain cultivated under stress conditions presents enhanced expression of phage anti-repressor genes, suggesting switches from lysogenic to lytic cycle of phages under stress-induced situations. Furthermore, virulence-associated proteins and toxins are found within these prophage-like elements, thus suggesting an important role in host adaptation. Finally, clustering analyses of phage integrase genes based on multiple alignment patterns reveal they group in five lineages, all possessing a tyrosine recombinase catalytic domain, and phylogenetically close to other integrases found in phages that are genetic mosaics and able to perform generalized and specialized transduction. Integration sites and tRNA association is also evidenced. In summary, we present comparative and experimental evidence supporting the association and contribution of phage activity on the differentiation of Xylella genomes

Occurrence of eggs and oocysts of gastrointestinal parasites in passerine birds kept in captivity in Para State, Brazil Ocorrência de ovos e oocistos de parasitos gastrointestinais em aves Passeriformes mantidas em cativeiro no estado do Pará, Brasil

ABSTRACT The objective of this study was to detect helminth eggs and protozoan oocysts in samples of feces from birds of the orde

Neurostimulation Combined With Cognitive Intervention in Alzheimer’s Disease (NeuroAD): Study Protocol of Double-Blind, Randomized, Factorial Clinical Trial

Despite advances in the treatment of Alzheimer’s disease (AD), there is currently no prospect of a cure, and evidence shows that multifactorial interventions can benefit patients. A promising therapeutic alternative is the use of transcranial direct current stimulation (tDCS) simultaneously with cognitive intervention. The combination of these non-pharmacological techniques is apparently a safe and accessible approach. This study protocol aims to compare the efficacy of tDCS and cognitive intervention in a double-blind, randomized and factorial clinical trial. One hundred participants diagnosed with mild-stage AD will be randomized to receive both tDCS and cognitive intervention, tDCS, cognitive intervention, or placebo. The treatment will last 8 weeks, with a 12-month follow-up. The primary outcome will be the improvement of global cognitive functions, evaluated by the AD Assessment Scale, cognitive subscale (ADAS-Cog). The secondary outcomes will include measures of functional, affective, and behavioral components, as well as a neurophysiological marker (Brain-derived neurotrophic factor, BDNF). This study will enable us to assess, both in the short and long term, whether tDCS is more effective than the placebo and to examine the effects of combined therapy (tDCS and cognitive intervention) and isolated treatments (tDCS vs. cognitive intervention) on patients with AD.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02772185—May 5, 2016

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

A precarização na sala de aula: reflexões sobre seus efeitos na ótica docente

Este trabalho visa analisar os impactos das condições precárias do trabalho docente na sala de aula, na ótica dos professores. Partimos da análise dos dados de duas pesquisas realizadas em duas escolas públicas da cidade de Maceió/AL, cujos dados foram coletados através da ferramenta da Autoconfrontação desenvolvida por Yves Clot na Clinica da Atividade. As escolas apresentam em comum um grau extremo de dificuldades institucionais que se refletem na sala de aula, fruto de condições materiais precárias. Essa precariedade, e os problemas decorrentes, já são considerados normais pela frequência que ocorrem. Dessa forma, esses problemas estariam irremediavelmente se constituindo no próprio gênero da profissão docente, comprometendo a qualidade do ensino de maneira geral. Para Clot (2007), é o gênero que carrega os procedimentos, as atitudes e as posturas desenvolvidas ao longo da história e serve como orientador para o coletivo profissional, definindo as normas, portanto, o que é aceitável ou não no trabalho. Esse processo de precarização vem afetando negativamente também a profissão docente.Palavras-chave: Precarização do trabalho docente. Atividade docente. Clínica da Atividade. Gênero.Precariousness in the classroom: effects on teacher’s perspectiveAbstractThis study aims to analyse the impacts of precarious conditions of teachers’ work in classroom, in the view of teachers. We start from the analysis of data of two researches conducted in two public schools in the city of Maceió/AL, which were collected through self-confrontation tools developed by Yves Clot at Activity Clinic. The schools have in common an extreme degree of institutional difficulties which are reflected in the classroom, as a result of the poor conditions. This precariousness and problems related are already considered normal by the frequency they occur. Thus, these problems would irreparably constitute the very genre of the teaching profession, compromising the quality of education in general. For Clot (2007), is the genre that carries the procedures, attitudes and behaviors developed through history and serves as guide to the professional collectivity, setting standards and what is acceptable or not at work. This process of precauriousness is negatively affecting the teaching profession as well.Key words: Precariousness of teaching work. Teaching activity. Activity Clinic. Genre.  </p

Characterization of the Phenol Monooxygenase Gene from Chromobacterium violaceum: Potential Use for Phenol Biodegradation

In this work, the biodegradation mechanism of phenol and sub products (such as catechol and hydroquinone) in Chromobacterium violaceum was investigated by cloning and molecular characterization of a phenol monooxygenase gene in Escherichia coli. This gene (Cvmp) is very similar (74 and 59% of similarity and identity, respectively) to the ortholog from Ralstonia eutropha, bacteria capable of utilizing phenol as the sole carbon source. The phenol biodegradation ability of E. coli recombinant strains was tested by cell-growth in a minimal medium containing phenol as the sole source of carbon and release of intermediary metabolites (catechol and hydroquinone). Interestingly, during the growth of these strains on phenol, catechol, and hydroquinone accumulated transiently in the medium. These metabolites were further analyzed by HPLC. These results indicated that phenol can be initially orto or para hydroxylated to produce cathecol or hydroquinone, respectively, followed by meta-cleavage of aromatic rings. To verify this information, the metabolites obtained from HPLC were submitted to LC/MS to confirm their chemical structure, thereby indicating that the recombinant strains utilize two different routes simultaneously, leading to different ring-fission substrates for the metabolism of phenol. (C) KSBBConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq (Brasilia, DF, Brazil)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP (Sao Paulo, SP, Brazil

Sazonalidade dos elementos do clima e sua influência na serapilheira em uma floresta sucessional na Amazônia oriental

The production and decomposition of litter is important in the functioning and dynamic of a forest ecosystem, associating climatological variables to biomass. With that, the litter stock was investigated due to the seasonality of the climate in a successional forest in eastern Amazon. The study was conducted in a successional forest, in the metropolitan region of Belém (RMB), Pará. In the ecosystem, a random sampling was performed in three transects located along the perpendicular of the 50m border line. The analysis of the effect of the seasonality of the elements of the climate on the litter physical properties (volume, thickness, density and dry mass) and carbon content were carried out using the t Student test and ANOVA of the F test at 5% significance level. Precipitation (495.2 ± 125mm and 109.8 ± 60mm) and relative humidity (89.0 ± 1.7% and 79.6 ± 2.8%) showed a statistical difference in seasonality (p&lt;0.05), different from the temperature (27.1 ± 0.2ºC and 27.6 ± 0.3ºC), there was no difference. The litter variables were not influenced by the seasonality of the elements of the climate and did not differ statistically between the rainy and less rainy periods, respectively: amount of accumulated litter (16.46 ± 4.17 Mg.ha-1 and 13.91 ± 7.61 Mg.ha-1), litter carbon stock (7.9 ± 2, 0 Mg.ha-1 and 6.6 ± 3.61 Mg.ha-1), volume (26.21 ± 0.92cm3 and 24.88 ± 0.92 cm3), thickness (4.19 ± 0.92cm and 3.99 ± 0.95cm) and density (0.041 ± 0.92g/cm3 and 0.034 ± 0.92 g/cm3). The seasonality of the elements of the climate did not show considerable variation to the point of altering the litter physical properties and carbon content.A produção e decomposição da serapilheira é importante no funcionamento e na dinâmica de um ecossistema florestal, associando variáveis climatológicas à biomassa. Com isso, investigou-se o estoque de serapilheira em função da sozanalidade dos elementos do clima em uma floresta sucessional na Amazônia oriental. O estudo foi conduzido em uma floresta sucessional, na Região Metropolitana de Belém (RMB), Pará. No ecossistema foi realizada uma amostragem aleatória em três transectos alocados ao longo da perpendicular da linha de borda de 50 m. A análise do efeito da sazonalidade dos elementos do clima nas propriedades físicas (volume, espessura, densidade e massa seca) e no carbono da serapilheira foram realizadas utilizando o teste t student e ANOVA do teste F a 5% de significância. A precipitação (495,2±125mm e 109,8±60mm) e a umidade relativa do ar (89,0±1,7% e 79,6±2,8%) apresentaram diferença estatística na sazonalidade (p&lt;0,05), diferente da temperatura (27,1±0,2ºC e 27,6±0,3ºC) que não houve diferença. As variáveis da serapilheira não foram influenciadas pela sazonalidade dos elementos do clima e não diferiram estatisticamente entre os períodos chuvoso e menos chuvoso, respectivamente: quantidade de serapilheira acumulada (16,46±4,17 Mg ha-1 e 13,91±7,61 Mg ha-1), estoque de carbono da serapilheira (7,9±2,0 Mg ha-1 e 6,6 ± 3,61 Mg ha-1), volume (26,21±0,92cm3 e 24,88±0,92cm3), espessura (4,19±0,92cm e 3,99±0,95cm) e densidade (0,041±0,92g/cm3 e 0,034±0,92 g/cm3). A sazonalidade dos elementos do clima não apresentou variação considerável a ponto de alterar as propriedades físicas e o carbono da serapilheira