546 research outputs found

    Culture of history, public history, and history teaching : the investigation and the training of history teachers.

    Get PDF
    O artigo avalia a maneira como estudantes de hist?ria se relacionam com a cultura de hist?ria. Primeiro, discutimos as rela??es entre cultura de hist?ria, hist?ria p?blica e ensino de hist?ria. Na segunda parte, avaliamos as pol?ticas de forma??o e defendemos a investiga??o como princ?pio educativo para a forma??o. Na ?ltima, apresentamos a experi?ncia de produ??o de narrativas curtas produzidas pelos estudantes sobre a cultura de hist?ria. Nas tr?s partes, trazemos as vozes dos estudantes e sua reflex?o sobre a cultura de hist?ria. Defendemos que esse m?todo pode ser ?til no questionamento das rela??es sens?veis e racionais que mantemos com a hist?ria.The article assesses how students of History relate to the culture of History. First, we discuss the relationships between the culture of History, public History, and the teaching of History. The second part evaluates the policies for the formation of History teachers and defends research as an educational principle for their training. In the latter, we present the experience of producing short narratives produced by students about the culture of History. In the three parts, we bring the students? voices and their reflection on the culture of History. We argue that this method can be useful in questioning the sensible and rational relations that we maintain with History

    Distribution of transpulmonary pressure during one-lung ventilation in pigs at different body positions

    Get PDF
    Background. Global and regional transpulmonary pressure (PL) during one-lung ventilation (OLV) is poorly characterized. We hypothesized that global and regional PL and driving PL (ΔPL) increase during protective low tidal volume OLV compared to two-lung ventilation (TLV), and vary with body position.Methods. In sixteen anesthetized juvenile pigs, intra-pleural pressure sensors were placed in ventral, dorsal, and caudal zones of the left hemithorax by video-assisted thoracoscopy. A right thoracotomy was performed and lipopolysaccharide administered intravenously to mimic the inflammatory response due to thoracic surgery. Animals were ventilated in a volume-controlled mode with a tidal volume (VT) of 6 mL kg−1 during TLV and of 5 mL kg−1 during OLV and a positive end-expiratory pressure (PEEP) of 5 cmH2O. Global and local transpulmonary pressures were calculated. Lung instability was defined as end-expiratory PL<2.9 cmH2O according to previous investigations. Variables were acquired during TLV (TLVsupine), left lung ventilation in supine (OLVsupine), semilateral (OLVsemilateral), lateral (OLVlateral) and prone (OLVprone) positions randomized according to Latin-square sequence. Effects of position were tested using repeated measures ANOVA.Results. End-expiratory PL and ΔPL were higher during OLVsupine than TLVsupine. During OLV, regional end-inspiratory PL and ΔPL did not differ significantly among body positions. Yet, end-expiratory PL was lower in semilateral (ventral: 4.8 ± 2.9 cmH2O; caudal: 3.1 ± 2.6 cmH2O) and lateral (ventral: 1.9 ± 3.3 cmH2O; caudal: 2.7 ± 1.7 cmH2O) compared to supine (ventral: 4.8 ± 2.9 cmH2O; caudal: 3.1 ± 2.6 cmH2O) and prone position (ventral: 1.7 ± 2.5 cmH2O; caudal: 3.3 ± 1.6 cmH2O), mainly in ventral (p ≤ 0.001) and caudal (p = 0.007) regions. Lung instability was detected more often in semilateral (26 out of 48 measurements; p = 0.012) and lateral (29 out of 48 measurements, p < 0.001) as compared to supine position (15 out of 48 measurements), and more often in lateral as compared to prone position (19 out of 48 measurements, p = 0.027).Conclusion. Compared to TLV, OLV increased lung stress. Body position did not affect stress of the ventilated lung during OLV, but lung stability was lowest in semilateral and lateral decubitus position

    Regional lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in experimental lung injury

    Get PDF
    INTRODUCTION: There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute lung injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional lung aeration and ventilation during ALI are only poorly defined. METHODS: In 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at lung apex, hilum and base. RESULTS: Compared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern. CONCLUSIONS: In this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean

    Duality in a fermion-like formulation for the electromagnetic field

    Get PDF
    We employ the Dirac-like equation for the gauge field proposed by Majorana to obtain an action that is symmetric under duality transformation. We also use the equivalence between duality and chiral symmetry in this fermion-like formulation to show how the Maxwell action can be seen as a mass term.Comment: 4 pages. Revtex. Final version to be published in Phys. Rev.

    Role of estrogen related receptor beta (ESRRB) in DFN35B hearing impairment and dental decay

    Get PDF
    BACKGROUND: Congenital forms of hearing impairment can be caused by mutations in the estrogen related receptor beta (ESRRB) gene. Our initial linkage studies suggested the ESRRB locus is linked to high caries experience in humans. METHODS: We tested for association between the ESRRB locus and dental caries in 1,731 subjects, if ESRRB was expressed in whole saliva, if ESRRB was associated with the microhardness of the dental enamel, and if ESRRB was expressed during enamel development of mice. RESULTS: Two families with recessive ESRRB mutations and DFNB35 hearing impairment showed more extensive dental destruction by caries. Expression levels of ESRRB in whole saliva samples showed differences depending on sex and dental caries experience. CONCLUSIONS: The common etiology of dental caries and hearing impairment provides a venue to assist in the identification of individuals at risk to either condition and provides options for the development of new caries prevention strategies, if the associated ESRRB genetic variants are correlated with efficacy.Fil: Weber, Megan L.. University of Pittsburgh; Estados UnidosFil: Hsin, Hong Yuan. University of Pittsburgh; Estados UnidosFil: Kalay, Ersan. Karadeniz Technical University; TurquíaFil: Brožková, Dana Š. Charles University; República Checa. University Hospital Motol; República ChecaFil: Shimizu, Takehiko. Nihon University. School of Dentistry; JapónFil: Bayram, Merve. Medipol Istanbul University; TurquíaFil: Deeley, Kathleen. University of Pittsburgh; Estados UnidosFil: Küchler, Erika C.. University of Pittsburgh; Estados UnidosFil: Forella, Jessalyn. University of Pittsburgh; Estados UnidosFil: Ruff, Timothy D.. University of Pittsburgh; Estados UnidosFil: Trombetta, Vanessa M.. University of Pittsburgh; Estados UnidosFil: Sencak, Regina C.. University of Pittsburgh; Estados UnidosFil: Hummel, Michael. University of Pittsburgh; Estados UnidosFil: Briseño Ruiz, Jessica. University of Pittsburgh; Estados UnidosFil: Revu, Shankar K.. University of Pittsburgh; Estados UnidosFil: Granjeiro, José M.. Universidade Federal Fluminense; BrasilFil: Antunes, Leonardo S.. Universidade Federal Fluminense; BrasilFil: Antunes, Livia A.. Universidade Federal Fluminense; BrasilFil: Abreu, Fernanda V.. Universidade Federal Fluminense; BrasilFil: Costabel, Marcelo C.. Universidade Federal do Rio de Janeiro; BrasilFil: Tannure, Patricia N.. Veiga de Almeida University; Brasil. Salgado de Oliveira University; BrasilFil: Koruyucu, Mine. Istanbul University; TurquíaFil: Patir, Asli. Medipol Istanbul University; TurquíaFil: Poletta, Fernando Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mereb, Juan C.. Estudio Colaborativo Latino Americano de Malformaciones Congénitas; ArgentinaFil: Castilla, Eduardo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orioli, Iêda M.. Universidade Federal do Rio de Janeiro; BrasilFil: Marazita, Mary L.. University of Pittsburgh; Estados UnidosFil: Ouyang, Hongjiao. University of Pittsburgh; Estados UnidosFil: Jayaraman, Thottala. University of Pittsburgh; Estados UnidosFil: Seymen, Figen. Istanbul University; TurquíaFil: Vieira, Alexandre R.. University of Pittsburgh; Estados Unido

    Effective Action for QED with Fermion Self-Interaction in D=2 and D=3 Dimensions

    Get PDF
    In this work we discuss the effect of the quartic fermion self-interaction of Thirring type in QED in D=2 and D=3 dimensions. This is done through the computation of the effective action up to quadratic terms in the photon field. We analyze the corresponding nonlocal photon propagators nonperturbatively in % \frac{k}{m}, where k is the photon momentum and m the fermion mass. The poles of the propagators were determined numerically by using the Mathematica software. In D=2 there is always a massless pole whereas for strong enough Thirring coupling a massive pole may appear . For D=3 there are three regions in parameters space. We may have one or two massive poles or even no pole at all. The inter-quark static potential is computed analytically in D=2. We notice that the Thirring interaction contributes with a screening term to the confining linear potential of massive QED_{2}. In D=3 the static potential must be calculated numerically. The screening nature of the massive QED3_{3} prevails at any distance, indicating that this is a universal feature of % D=3 electromagnetic interaction. Our results become exact for an infinite number of fermion flavors.Comment: Latex, 13 pages, 3 figure

    Anatomical study of the mandibular canal course in felines (Felis catus domesticus)

    Get PDF
    Objetivou-se descrever, por meio de tomografia computadorizada, o trajeto do canal mandibular (CM) em 20 gatos sem raça definida, com ausência de alterações na cavidade oral, provenientes do Centro de Controle de Zoonoses do Distrito Federal. Foram realizados cortes tomográficos com 2mm de espessura, acompanhando todo o trajeto do CM, tendo como referência a região do forame mandibular, as raízes distais e mesiais dos dentes pré-molares e molares e o forame mentoniano, obtendo-se medidas desde o CM até as faces vestibular, lingual, ventral e alveolar (profundidade) do corpo da mandíbula, bem como seu diâmetro. Pôde constatar que o CM manteve-se no aspecto lingual do corpo da mandíbula desde o forame mandibular até a raiz mesial do 1º pré-molar, onde se deslocou para a face vestibular, emergindo no forame mentoniano. Com relação à profundidade, seu trajeto sofreu declive a partir do forame mandibular até a região da raiz mesial do 1º molar, onde alcançou seu ponto mais profundo para prosseguir em suave ascensão até o forame mentoniano. Os dados apresentados contribuem para o estudo anatômico da mandíbula de gatos, bem como auxiliam no melhor planejamento e execução de procedimentos cirúrgicos na mandíbula dessa espécie.This study aimed to describe the path of the mandibular canal (MC), using computerized tomography, in twenty mongrel cats, with no changes in the oral cavity, from the Zoonosis Control Center of the Federal District. 2mm thick tomographic sections were taken following the entire path of the mandibular canal, considering as reference the region of the mandibular foramen, the distal and mesial roots of premolar and molar teeth, and mental foramen, obtaining measurements from the MC until the buccal, lingual, ventral and alveolar (depth) surfaces of the mandibular body as well as its diameter. MC remained on the lingual aspect of the mandibular body from the mandibular foramen to the mesial root of the first premolar, where it displaced to the buccal surface, emerging from the mental foramen. Regarding the depth, we observed a downward path from the mandibular foramen to the mesial root of the first premolar, where it reached its deepest point, the path continued in gentle ascent until to the mental foramen. Our data contribute to the anatomical study of the feline jaw and allow a better planning and execution of surgical procedures in the mandible of this species

    Peso medio al nacer entre recién nacidos a término : tendencia, magnitud y factores asociados

    Get PDF
    A trend towards increasing birth weight has been shown, but factors that explain these trends have not been elucidated. The objectives of this study were to evaluate changes in mean birth weight of term newborns and to identify factors associated with them. All cohorts are population-based studies in which random samples of births (Ribeirão Preto, São Paulo State in 1978/1979, 1994 and 2010; Pelotas, Rio Grande do Sul State in 1982, 1993 and 2004; and São Luís, Maranhão State in 1997/1998 and 2010, Brazil). A total of 32,147 full-term, singleton live births were included. Mean birth weight reduced in the first study period (-89.1g in Ribeirão Preto from 1978/1979 to 1994, and -27.7g in Pelotas from 1982 to 1993) and increased +30.2g in Ribeirão Preto from 1994 to 2010 and +24.7g in São Luís from 1997 to 2010. In the first period, in Ribeirão Preto, mean birth weight reduction was steeper among mothers with high school education and among those born 39-41 weeks. In the second period, the increase in mean birth weight was steeper among mothers with low schooling in Ribeirão Preto and São Luís, females and those born 37-38 weeks in Ribeirão Preto and cesarean section in São Luís. Birth weight decreased in the first study period then increased thereafter. The variables that seem to have been able to explain these changes varied over time.Existem evidências de uma tendência de aumento do peso ao nascer, mas pouco se sabe sobre os fatores que explicam essa tendência. Avaliar as mudanças na média de peso ao nascer e identificar os fatores associados. Foram incluídas todas as coortes de base populacional com amostras aleatórias de nascimentos (Ribeirão Preto, São Paulo em 1978/1979, 1994 e 2010; Pelotas, Rio Grande do Sul em 1982, 1993 e 2004; São Luís, Maranhão em 1997/1998 e 2010, Brasil). Foi incluído um total de 32.147 nascidos vivos a termo, de feto único. A média de peso ao nascer diminuiu no primeiro período estudado (-89,1g entre 1978/1979 e 1994 em Ribeirão Preto e -27,7g entre 1982 e 1993 em Pelotas) e aumentou no segundo período, +30,2g entre 1994 e 2010 em Ribeirão Preto e +24,7g entre 1997 e 2010 em São Luís. No primeiro período, em Ribeirão Preto, a redução na média de peso ao nascer foi maior entre mães com escolaridade mais alta e crianças nascidas com 39-41 semanas de idade gestacional. No segundo período, o aumento na média de peso ao nascer foi maior entre mães com escolaridade mais baixa em Ribeirão Preto e São Luís, crianças do sexo feminino e nascidas com 37-38 semanas em Ribeirão Preto e crianças nascidas de cesárea em São Luís. O peso ao nascer diminuiu no primeiro período e aumentou desde então. As variáveis que parecem explicar essas mudanças variaram ao longo do tempo.Se ha mostrado una tendencia de aumento de peso al nacer, pero los factores que explican esta tendencia todavía no han sido elucidados. Evaluar los cambios en el peso medio al nacer de los recién nacidos a término e identificar factores asociados. Se trata de un estudio de todas las cohortes basadas en población, donde existe una muestra aleatoria simple de nacimientos (Ribeirão Preto, São Paulo en 1978/1979, 1994 y 2010; Pelotas, Rio Grande do Sul en 1982, 1993 y 2004; y São Luís, Maranhão en 1997/1998 y 2010, Brasil). Se incluyeron un total de 32.147 de nacimientos a término completo con embarazo de un único feto. El peso medio al nacer se redujo en el primer estudio del período (-89,1g en Ribeirão Preto desde 1978/1979 a 1994 y -27,7g en Pelotas desde 1982 a 1993) y se incrementó +30,2g en Ribeirão Preto desde 1994 a 2010 y +24.7g en São Luís desde 1997 a 2010. En el primer periodo, en Ribeirão Preto, la reducción del peso medio al nacer fue más pronunciada entre madres con una escolarización más alta y entre aquellos nacidos con 39-41 semanas. En el segundo período, el incremento en el peso medio al nacer fue más pronunciado entre las madres con una escolarización más baja en Ribeirão Preto y São Luís, mujeres y aquellos que nacieron con 37-38 semanas en Ribeirão Preto y en el área de cesáreas en São Luís. Disminuyó el peso al nacer durante el primer período de estudio y se vio incrementado después. Las variables que parecen capaces de explicar estos cambios varían a lo largo del tiempo

    Lung-protective ventilation for the surgical patient: international expert panel-based consensus recommendations

    Get PDF
    Postoperative pulmonary complications (PPCs) occur frequently and are associated with substantial morbidity and mortality. Evidence suggests that reduction of PPCs can be accomplished by using lung-protective ventilation strategies intraoperatively, but a consensus on perioperative management has not been established. We sought to determine recommendations for lung protection for the surgical patient at an international consensus development conference. Seven experts produced 24 questions concerning preoperative assessment and intraoperative mechanical ventilation for patients at risk of developing PPCs. Six researchers assessed the literature using questions as a framework for their review. The modified Delphi method was utilised by a team of experts to produce recommendations and statements from study questions. An expert consensus was reached for 22 recommendations and four statements. The following are the highlights: (i) a dedicated score should be used for preoperative pulmonary risk evaluation; and (ii) an individualised mechanical ventilation may improve the mechanics of breathing and respiratory function, and prevent PPCs. The ventilator should initially be set to a tidal volume of 6-8 ml kg-1 predicted body weight and positive end-expiratory pressure (PEEP) 5 cm H2O. PEEP should be individualised thereafter. When recruitment manoeuvres are performed, the lowest effective pressure and shortest effective time or fewest number of breaths should be used. ispartof: BJA: British Journal of Anaesthesia vol:123 issue:6 pages:898-913 ispartof: location:England status: Published onlin
    • …
    corecore