467 research outputs found
Black-Hole Mass and Growth Rate at High Redshift
We present new H and K bands spectroscopy of 15 high luminosity active
galactic nuclei (AGNs) at redshifts 2.3-3.4 obtained on Gemini South. We
combined the data with spectra of additional 29 high-luminosity sources to
obtain a sample with 10^{45.2}<\lambda L_{\lambda}(5100A)<10^{47.3} ergs/sec
and black hole (BH) mass range, using reverberation mapping relationships based
on the H_beta method, of 10^{8.8}-10^{10.7} M_sun. We do not find a correlation
of L/L_Edd with M_BH but find a correlation with \lambda L_{\lambda}(5100A)
which might be due to selection effects. The L/L_Edd distribution is broad and
covers the range ~0.07-1.6, similar to what is observed in lower redshift,
lower luminosity AGNs. We suggest that this consistently measured and
calibrated sample gives the best representation of L/L_Edd at those redshifts
and note potential discrepancies with recent theoretical and observational
studies. The lower accretion rates are not in accord with growth scenarios for
BHs at such redshifts and the growth times of many of the sources are longer
than the age of the universe at the corresponding epochs. This suggests earlier
episodes of faster growth at z>~3 for those sources. The use of the C IV method
gives considerably different results and a larger scatter; this method seems to
be a poor M_BH and L/L_Edd estimator at very high luminosity.Comment: 8 pages (emulateapj), 4 figures. Accepted for publication in Ap
Hypoxically Induced Nitric Oxide: Potential Role as a Vasodilator in Mytilus edulis Gills
Intertidal Mytilus edulis experience rapid transgression to hypoxia when they close theirvalves during low tide. This induces a physiological stress response aiming to stabilizetissue perfusion against declining oxygen partial pressure in shell water.We hypothesizedthat nitric oxide (NO) accumulation supports blood vessel opening in hypoxia andused live imaging techniques to measure NO and superoxide anion (O?−2 ) formationin hypoxia-exposed gill filaments. Thirty minutes of moderate (7 kPa pO2) and severehypoxia (1 kPa pO2) caused 1.6- and 2.4-fold increase, respectively, of NO accumulationin the endothelial muscle cells of the hemolymphatic vessels of the gill filaments. This ledto a dilatation of blood vessel diameter by 43% (7 kPa) and 56% (1 kPa), which facilitatesblood flow. Experiments in which we applied the chemical NO-donor Spermine NONOate(concentrations ranging from 1 to 6mM) under normoxic conditions corroborate thedilatational effect of NO on the blood vessel. The formation of O?−2 within the filamentepithelial cells increased 1.5 (7 kPa) and 2-fold (1 kPa) upon treatment. Biochemicalanalysis of mitochondrial electron transport complexes in hypoxia-exposed gill tissueindicates decreased activity of complexes I and III in both hypoxic conditions; whereascomplex IV (cytochrome-c oxidase) activity increased at 7 kPa and decreased at 1kPa compared to normoxic exposure conditions. This corresponds to the pattern ofpO2-dependent gill respiration rates recorded in ex-vivo experiments. Severe hypoxia(1 kPa) appears to have a stabilizing effect on NO accumulation in gill cells, sinceless O2 is available for NO oxidation to nitrite/nitrate. Hypoxia thus supports theNO dependent inhibition of complex IV activity, a mechanism that could fine tunemitochondrial respiration to the local O2 availability in a tissue. Our study highlights abasal function of NO in improving perfusion of hypoxic invertebrate tissues, which couldbe a key mechanism of tolerance toward environmental O2 variations.Fil: González, Paula Mariela. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de BioquÃmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquÃmica y Medicina Molecular; ArgentinaFil: Rocchetta, Iara. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Abele, Doris. Alfred Wegener Institute For Polar And Marine Research; AlemaniaFil: Rivera Ingraham, Georgina A.. Alfred Wegener Institute For Polar And Marine Research; Alemani
Viral hepatitis and the immunological response: a review
Introduction: In Brazil, viral hepatitis is infectious disease of compulsory notification and is considered a serious public health problem. Infections with A, B, C, D or E viruses trigger the activation of immune system molecules and cells at the level of innate and acquired immunity. Objective: The present study aimed to review the knowledge about viral hepatitis and the immune system's performance against these infections. Methods: This is a literature overview from academic books and scientific articles available in the Scientific Electronic Library Online, US National Library of Medicine National Institutes of Health and Google Scholar databases. Having as key words hepatitis A, hepatitis B, hepatitis C, hepatitis D, hepatitis E and immune system. The relevant articles corresponding to the period between 1974 and 2017 were selected. Development: Viral hepatitis is characterized by inflammation in liver cells caused by groups of viruses that have hepatotropism in common. The diagnosis is made through serological methods and molecular biology techniques. The approach of the immune system in relation to the combat of this infection follows same particularities. Conclusion: This review demonstrated that the determination of the etiologic agent is essential for the conduct to be taken with the infected individual. Moreover, the immune system is directed related to the viruses elimination, presenting some particularities. In addition, this review highlights that the vaccination is the main responsible for reducing people infected by viruses A and B
Oviposition Behavior of Ceratitis capitata Wiedemann (Diptera: Tephritidae): Association Between Oviposition Preference and Larval Performance in Individual Females
Expectativas y percepciones de la madre respecto a su recién-nacido: aplicación del inventario de percepción neonatal de broussard
OBJECTIVES: To evaluate Broussard's Neonatal Perception Inventory (BPNI), an instrument to measure the mother's perception and expectations regarding her newborn infant at immediate postpartum and one month afterwards in primiparous and multiparous women. METHODS: Prospective cohort of 27 multiparous and 29 primiparous mothers of healthy newborn infants. In the second day postpartum, mothers were asked about the difficulties they thought that babies would offer regarding specific behaviors: crying, spitting, feeding, elimination, sleeping and predictability. Answers were rated in a 5-point scale. Next, mothers were questioned about their own babies regarding the same items. After 30 days, the mothers were questioned again about her perception of most babies and their own baby regarding the same items. The results were analyzed by repeated measures ANOVA considering the following main effects: time, group (primiparous and mul-tiparous), and subjects (mother's baby and most babies). RESULTS: Following birth, mothers expected their babies to have fewer difficulties in the daily activities than the ma-jority of the babies. These expectations were confirmed one month later for all items. There were no differences between primiparous and multiparous mothers. CONCLUSIONS: The Broussard's Neonatal Perception In-ventory was well understood and accepted by mothers and showed consistent results in this study. It can be used as a screening psychological tool to assess bonding between mothers and infants.OBJETIVOS: Analizar el Inventario de Percepción Neonatal de Broussard (BNPI - un instrumento que detecta las percepciones y expectativas maternas respecto a los hijos) enseguida al parto (T1) y con un mes de vida (T2), en puér-peras multÃparas y primÃparas. MÉTODOS: Coorte prospectiva con 27 multÃparas y 29 primÃparas madres de neonatos a término sanos. Se preguntó a la madre en T1 la dificultad que ella esperaba que la mayorÃa de los bebés tuviera respecto a llorar, alimentarse, regurgitar o vomitar, evacuar, dormir y tener una rutina. Las respuestas fueron marcadas en una escala de 5 puntos. Enseguida, se repitieron las preguntas respecto a su hijo recién-nacido. En T2, se preguntaba a la madre la dificultad que ella creÃa que la mayorÃa de los bebés y su propio hijo presentaban respecto a los mismos requisitos. El análisis estadÃstico utilizó ANOVA para medidas repetidas, teniendo en cuenta los siguientes efectos principales: tiempo (T1 y T2), grupo (primÃparas y multÃparas) y categorÃa (su bebé y la mayorÃa de los bebés). RESULTADOS: Enseguida al parto, las madres esperaban que sus hijos tuvieran menos dificultad en las actividades evaluadas que la mayorÃa de los bebés. Esta expectativa se confirmó con 30 dÃas de vida para todos los comportamientos. No hubo diferencias entre primÃparas y multÃparas. CONCLUSIONES: El BNPI fue bien atendido y aceptado por las madres, mostrando resultados consistentes en este estudio. El instrumento puede ser útil para seleccionar pares madre-bebé con dificultades en el establecimiento de vÃnculo.OBJETIVOS: Analisar o Inventário de Percepção Neonatal de Broussard, um instrumento que detecta as percepções e expectativas maternas com respeito aos filhos logo após o parto (Tempo 1) e com um mês de vida (Tempo 2), em puérperas multÃparas e primÃparas. MÉTODOS: Coorte prospectiva com 27 multÃparas e 29 primÃparas mães de neonatos a termo saudáveis. Inquiriu-se à mãe no segundo dia pós-parto quanta dificuldade ela esperava que a maioria dos bebês tivesse em relação a chorar, alimentar, regurgitar ou vomitar, evacuar, dormir e ter uma rotina. As respostas foram marcadas em uma escala de 5 pontos. A seguir, repetiam-se as perguntas em relação ao seu filho recém-nascido. Após 30 dias, perguntava-se à mãe quanta dificuldade ela achava que a maioria dos bebês e seu próprio filho apresentavam em relação aos mesmos quesitos. A análise estatÃstica utilizou ANOVA para medidas repe-tidas, considerando os seguintes efeitos principais: tempo, grupo (primÃparas e multÃparas) e categoria (seu bebê e a maioria dos bebês). RESULTADOS: Logo após o parto, as mães esperavam que seus filhos tivessem menos dificuldade nas atividades avalia-das do que a maioria dos bebês. Essa expectativa se confirmou com 30 dias de vida para todos os comportamentos. Não houve diferenças entre primÃparas e multÃparas. CONCLUSÕES: O Inventário de Percepção Neonatal de Broussard foi bem entendido e aceito pelas mães, mostrando resultados consistentes neste estudo. O instrumento pode ser útil para triar pares mãe-bebê com dificuldades no estabelecimento de vÃnculo.Universidade Federal de São Paulo (UNIFESP)Sociedade Brasileira de Psicanálise de São PauloHospital Geral de Itapecerica da SerraUNIFESPSciEL
Recuperação pós-eletroconvulsoterapia: comparação entre propofol, etomidato e tiopental
OBJECTIVES: To compare post anesthetic time for patient recovery after electroconvulsive therapy, as measured by the post anesthetic Recovery Score of Aldrete and Kroulik, using three different types of hypnotic drugs (propofol, etomidate and thiopental). METHOD: Thirty patients were randomized to receive one of the three drugs (n = 10 in each group), during a course of electroconvulsive therapy treatment. Patients and raters were blinded to which drug was received. Main treatment characteristics were recorded (as total electric charge received seizure threshold, number of treatments, and the mean time for recovery) along the whole treatment. RESULTS: Thiopental and propofol were associated with a significance increase in charge needed to induce a seizure (p < 0.0001) when compared to etomidate, as well as a significant decrease of time for recovery (p = 0.042). CONCLUSIONS: These findings suggest that, although there seems to be no difference in the clinical outcome across these three drugs, propofol offers the best recovery profile. However, it makes a higher mean electric charge necessary.OBJETIVOS: Comparar o tempo de recuperação dos pacientes após eletroconvulsoterapia avaliada com a escala de recuperação pós-anestésica de Aldrete e Kroulik, utilizando três tipos de medicações anestésicas (propofol, etomidato and tiopental). MÉTODO: Trinta pacientes foram randomizados para receber uma das medicações (n = 10 em cada grupo) durante uma série de tratamentos com eletroconvulsoterapia. Os pacientes e o examinador ficaram cegos para o tipo de anestésico utilizado. As principais caracterÃsticas do tratamento foram avaliadas (como carga total de eletricidade recebida, limiar convulsivo, número de sessões e o tempo médio para recuperação) ao longo de toda a série de tratamentos. RESULTADOS: Tiopental e propofol se associaram a um aumento significativo na carga elétrica total utilizada (p < 0,0001) quando comparados com etomidato, bem como uma diminuição significativa no tempo de recuperação pós-anestésica (p = 0,042). CONCLUSÕES: Estes achados sugerem que, apesar de não haver diferença na evolução clÃnica entre os três grupos estudados, a droga propofol oferece o melhor perfil de recuperação apesar de requerer uma carga elétrica média maior
Immune Receptors and Co-receptors in Antiviral Innate Immunity in Plants
Plants respond to pathogens using an innate immune system that is broadly divided into PTI (pathogen-associated molecular pattern- or PAMP-triggered immunity) and ETI (effector-triggered immunity). PTI is activated upon perception of PAMPs, conserved motifs derived from pathogens, by surface membrane-anchored pattern recognition receptors (PRRs). To overcome this first line of defense, pathogens release into plant cells effectors that inhibit PTI and activate effector-triggered susceptibility (ETS). Counteracting this virulence strategy, plant cells synthesize intracellular resistance (R) proteins, which specifically recognize pathogen effectors or avirulence (Avr) factors and activate ETI. These coevolving pathogen virulence strategies and plant resistance mechanisms illustrate evolutionary arms race between pathogen and host, which is integrated into the zigzag model of plant innate immunity. Although antiviral immune concepts have been initially excluded from the zigzag model, recent studies have provided several lines of evidence substantiating the notion that plants deploy the innate immune system to fight viruses in a manner similar to that used for non-viral pathogens. First, most R proteins against viruses so far characterized share structural similarity with antibacterial and antifungal R gene products and elicit typical ETI-based immune responses. Second, virus-derived PAMPs may activate PTI-like responses through immune co-receptors of plant PTI. Finally, and even more compelling, a viral Avr factor that triggers ETI in resistant genotypes has recently been shown to act as a suppressor of PTI, integrating plant viruses into the co-evolutionary model of host-pathogen interactions, the zigzag model. In this review, we summarize these important progresses, focusing on the potential significance of antiviral immune receptors and co-receptors in plant antiviral innate immunity. In light of the innate immune system, we also discuss a newly uncovered layer of antiviral defense that is specific to plant DNA viruses and relies on transmembrane receptor-mediated translational suppression for defense
Differentiation Between Women With Vulvovaginal Symptoms Who are Positive or Negative for Candida Species by Culture
Objective: To investigate whether clinical criteria could differentiate between women with vulvovaginitis who were culture positive or negative for vaginal Candida species. Methods: Vulvovaginal specimens were obtained from 501 women with a vaginal discharge and/or pruritis. Clinical information and wet mount microscopy findings were obtained. All specimens were sent to a central laboratory for species identification. Results: A positive culture for Candida species was obtained from 364 (72.7%) of the specimens. C. albicans was identified in 86.4% of the positive cultures, followed by C. glabrata in 4.5%, C. parapsilosis in 3.9%, C. tropicalis in 2.7% and other Candida species in 1.4%.Women with a positive Candida culture had an increased utilization of oral contraceptives (26.1% vs. 16.8%, p = 0.02) and antibiotics (8.2% vs. 0.7%, p = 0.001), and were more likely to be pregnant (9.1% vs. 3.6%, p = 0.04) than the culture-negative women. Dyspareunia was more frequent in women without Candida (38.0% vs. 28.3%, p = 0.03) while vaginal erythema (p = 0.01) was more common in women with a positive Candida culture. Conclusions: Although quantitative differences were observed, the presence of vaginal Candida vulvovaginitis cannot be definitively identified by clinical criteria
Jovens urbanos: marcos conceituais e metodológicos
Esta publicação traz reflexões sobre o contexto das juventudes e as proposições conceituais e metodológicas do Programa Jovens Urbanos
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