649 research outputs found

    The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana

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    Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific ‘‘avirulent’’ pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NBLRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector

    Head-Toes-Knees-Shoulders task and EF in two samples of adolescents in Brazil and United States

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    Executive function (EF) is a foundational cognitive construct, which is linked to better cognitive and physical health throughout development. The present study examines the construct validity of an EF task, the Head-Toes-Knees-Shoulders task (HTKS) that was initially developed for young children, in a sample of adolescents. We investigate the initial validity and range in scores between 54 adolescents from Brazil (mean age 12.58) and 56 US adolescents (mean age 12.48) from different socioeconomic contexts. Results indicated that the HTKS showed sufficient variability in both samples, especially for a measure of HTKS efficiency (completion time divided by the total score). The US sample performed better on all cognitive measures. For the Brazilian sample, regression models controlling for age and sex showed a significant relationship between the digit span working memory task, the HTKS total score, and the HTKS efficiency score. The Heart and Flowers cognitive flexibility measure was also included as an independent variable only for the Brazil sample, showing a significant relationship with both HTKS scores. For the US sample, results showed that only the HTKS efficiency score was significantly related to the digit span working memory task. This study highlights the importance of cognitive efficiency measures to achieve greater validity, as they can assess a broader range of performance with different populations. The HTKS showed good ecological validity with two adolescent samples, as it differentiated between populations with high and low socioeconomic status from different cultural contexts

    A Repeated Measures Experiment of Green Exercise to Improve Self-Esteem in UK School Children

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    Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise. © 2013 Reed et al

    Transcriptional Responses of Arabidopsis thaliana during Wilt Disease Caused by the Soil-Borne Phytopathogenic Bacterium, Ralstonia solanacearum

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    Bacterial wilt is a common disease that causes severe yield and quality losses in many plants. In the present study, we used the model Ralstonia solanacearum-Arabidopsis thaliana pathosystem to study transcriptional changes associated with wilt disease development. Susceptible Col-5 plants and RRS1-R-containing resistant Nd-1 plants were root-inoculated with R. solanacearum strains harbouring or lacking the matching PopP2 avirulence gene. Gene expression was marginally affected in leaves during the early stages of infection. Major changes in transcript levels took place between 4 and 5 days after pathogen inoculation, at the onset of appearance of wilt symptoms. Up-regulated genes in diseased plants included ABA-, senescence- and basal resistance-associated genes. The influence of the plant genetic background on disease-associated gene expression is weak although some genes appeared to be specifically up-regulated in Nd-1 plants. Inactivation of some disease-associated genes led to alterations in the plant responses to a virulent strain of the pathogen. In contrast to other pathosystems, very little overlap in gene expression was detected between the early phases of the resistance response and the late stages of disease development. This observation may be explained by the fact that above-ground tissues were sampled for profiling whereas the bacteria were applied to root tissues

    Superconductivity up to 110 K in Bi2Sr2Ca2Cu3O10 compounds

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    In the Bi-Sr-Ca-Cu-O system, we have studied the compound with the ideal formula Bi2Sr2Ca2Cu3O10 , responsible for the superconductivity up to 110 K. The magnetic measurements reveal the presence of two phases in the samples with superconducting transitions up to 80 K and 110 K. By varying the composition and the thermal treatment of those samples, we have succeeded in increasing the amount of the superconducting phase with Tc up to 110 K. The Meissner effect reaches 30 % of - 3/8 π at 90 K for the undoped samples and more than 50 % for the samples doped with Pb. Because of the high reversibility of the magnetization versus magnetic field around Tc, we have evaluated the critical thermodynamic field. This one gives an electronic specific heat coefficient similar to the one of YBaCuO compounds.Nous avons étudié dans le système Bi-Si-Ca-Cu-O le composé responsable de la supraconductivité jusqu'à 110 K, de formule idéale Bi2Sr2Ca2Cu3O10. Les mesures d'aimantation montrent la présence de deux phases dans les échantillons, avec des transitions à 80 K et 110 K. En faisant varier la composition et les traitements thermiques de ces échantillons, nous avons réussi à augmenter la proportion de la phase supraconductrice jusqu'à 110 K. L'effet Meissner atteint 30 % de - 3/8 π à 90 K pour les échantillons non dopés et 50 % pour ceux dopés au plomb. La grande réversibilité des courbes d'aimantation en fonction du champ au voisinage de Tc nous a permis d'évaluer le champ critique thermodynamique. Celui-ci conduit à un coefficient de chaleur spécifique électronique similaire à celui des composés YBaCuO

    A construção dos prontuários como expressão da prática dos profissionais de saúde

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    O artigo aborda a temática da construção dos prontuários a partir de análise documental no sentido de entender as práticas dos profissionais de saúde que integram equipes de pré-natal de adolescentes em dois ambulatórios da rede pública de atenção básica de saúde estadual e municipal. Partindo da definição contemporânea de prontuário, que entende que, para além da missão de ser um instrumento jurídico de registro de propriedade do paciente, ele também atua como mediador da comunicação intraequipe de saúde e da comunicação dessa equipe com o usuário, fazemos um resgate histórico e crítico, baseado na análise de Michel Foucault sobre a origem do registro como tecnologia disciplinar que caracterizou o nascimento da instituição hospitalar e da clínica moderna. Identificamos que o aspecto comunicativo, segundo conceito do 'agir comunicativo' de Jürgen Habermas, vem sendo negligenciado pelas equipes pesquisadas, fruto de uma visão profissional focada no 'sigilo' e no individual em detrimento da construção de saberes coletivos.The focus of the paper is the construction of medical records by health professionals in two public health assistance services for pregnant teenagers. The medical record, beyond its judicial character, must be understood nowadays as a tool for promoting communication between the staff members, as well as between staff and patients, an instrument that mediates communication actions. Based on Michel Foucault's historical approach to registration as part of a disciplinary technology that emerges together with the modern hospital and clinical view, it was identified that health professionals neglect the communicative aspect, according to the concept of 'communicative acting' developed by Jürgen Habermas, of the registration action, and show a conception of clinical procedures based on 'secrecy' rather than a social construction of new knowledge
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